[0001]

The present invention relates to a rotary compressor.

[Background Art]

[0002]
Rotary compressors have been hitherto proposed that are provided with a roller (also referred to as a piston) that is rotatably mounted on an eccentric portion of a crankshaft, a cylinder that is formed with a cylindrical cylinder chamber that is arranged therein with the roller, and a vane that divides the inside of the cylinder chamber into two spaces, namely, a compression chamber and a suction chamber. In these rotary compressors, an eccentric rotational motion of the roller inside the cylinder chamber compresses a refrigerant that has been drawn into the cylinder chamber. In such conventional rotary compressors, rotary compressors have also been proposed in which the roller is divided into a plurality of components.

[0003]

For example, in conventional rotary compressors in which the roller is divided into a plurality of components, there have been proposed rotary compressors that is devised to prevent wear of a roller outer circumferential surface caused by sliding between a vane and the roller outer circumferential surface by "structuring a piston of the rotary compressor so as to have a double structure, namely, a first roller 16a on the outside and a second roller 16b on the inside, and by providing holes 24 through which an inner surface and an outer surface of the second roller 16b are in communication with each other." (see Patent Literature 1).

[0004]

Furthermore, for example, in conventional rotary compressors in which the roller is divided into an inner roller (corresponding to the first roller 16a of Patent Literature 1) and an outer roller (corresponding to the second roller 16b of Patent Literature 1), a rotary compressor has been proposed that is devised to reduce sliding loss between the inner roller and the outer roller in which "the rotary type compressor includes a cylinder, a main bearing and a sub bearing fixed to end faces of the cylinder, a shaft that rotatably slides inside the main bearing and sub bearing and that includes a crank, an inside roller that is divided into two in the shaft direction and that is rotatably received in the crank of the shaft, an outer roller that is fitted to the outside of the inner roller, a plurality of grooves that are formed at the end faces of the inner roller that face the main bearing and the sub bearing, the grooves formed by the communication portions and sealing portions of the inner circumferential surface portion of the inner roller, and a spring between the facing end faces of the inside roller that is divided into two." (see Patent Literature 2).

[0005]

Furthermore, for example, in conventional rotary compressors in which the roller is divided into a plurality of components, "a hermetic compressor including a cylinder, a rotating shaft having a shaft portion and an eccentric portion, a roller that is attached by insertion to the outer circumference of this eccentric portion and that rotates inside the cylinder, and bearings that seal the openings of the cylinder and that pivotally support the shaft, in which the roller is formed by dividing the roller into a plurality of ring bodies, and in which a relief for moving the divided ring bodies in the diameter direction of the rotating shaft is provided between the eccentric portion and the shaft portion of the rotating shaft" has been proposed (see Patent Literature 3).

[0006]

Furthermore, for example, in conventional rotary compressors provided with a roller that is similar to Patent Literature 2 in which the roller is divided into an inner roller and an outer roller and, further, in which the inner roller is divided into a plurality of components, a rotary compressor has been proposed "equipped with a rotating shaft 4 including a plurality of eccentric portions 4c and 4d in which a main shaft portion 4A and a sub shaft portion 4B are engaged to a roller 13a and 13b, and with a plurality of compression mechanisms 2A and 2B including a plurality of cylinders 8A and 8B provided with cylinder chambers 14a and 14b in which each roller eccentrically moves while being in contact with the corresponding peripheral wall. The rotary compressor is configured such that assuming that Rm is the radius of the main shaft portion, Rs is the radius of the sub shaft portion, Re is the radius of the eccentric portion, and e is the eccentricity of the eccentric portion, then Re < Rm + e and Re > Rs + e are satisfied, and assuming that, when the roller that engages with the eccentric portion of the main shaft portion is divided in the axis direction, ha is the height of the divided roller, H is the thickness of the cylinder, and L is the distance between adjacent end faces of the eccentric portions, then H > L and ha < L are satisfied." (see Patent Literature 4).

[0007]

Furthermore, for example, in conventional rotary compressors provided with a roller that is similar to Patent Literature 2 in which the roller is divided into an inner roller and an outer roller and, further, in which the inner roller is divided into a plurality of components, "a rotary compressor in which a piston, which eccentrically rotates along an inner wall of a cylinder, is structured with a double structure, and in which a second roller that has a smaller thermal expansion coefficient than a first roller on the outside is provided inside the piston" (see Patent literature 5) has been proposed.

[Citation List] [Patent Literature]

[0008]

[Patent Literature 1] Japanese Unexamined Patent Application Publication No. 5-256282 (Abstract, Fig. 1)

[Patent Literature 2] Japanese Unexamined Patent Application Publication No. 3-271591 (Claims, Fig. 1)

[Patent Literature 3] Japanese Unexamined Patent Application Publication No. 64-3290 (Claims, Fig. 1)

[Patent Literature 4] Japanese Unexamined Patent Application Publication No. 2008-157146 (Abstract, Figs. 2 and 5)

[Patent Literature 5] Japanese Unexamined Patent Application Publication No. 2-45683 (Claims, Fig. 2)

[Summary of Invention] [Technical Problem]

[0009]

Currently, due to increased awareness of energy saving and resource saving, downsizing of the rotary compressor is demanded; accordingly, there is a demand to further improve the efficiency of the rotary compressor. In order to achieve this, the thickness of the cylinder may be reduced. That is, reduction in the thickness of the cylinder allows downsizing of the rotary compressor. Furthermore, reduction in the thickness of the cylinder allows the clearance between the inner circumferential surface of the cylinder chamber and the outer circumferential surface of the roller to become smaller; accordingly, refrigerant loss due to leakage of refrigerant from between the two can be reduced, and the rotary compressor can be made to be highly efficient. However, reduction in the thickness of the cylinder reduces displacement. The eccentricity of the eccentric portion of the crankshaft needs to be increased in order to reduce the thickness of the cylinder without changing the displacement.

However, when attempting to increase the eccentricity of the eccentric portion of the crankshaft in conventional rotary compressors, the following problems arise.

[0010]

The crankshaft portion includes center shaft portions (a main shaft that is fixed to the rotor and that is rotatably supported by a main bearing, a sub shaft that is rotatably supported by a sub bearing, and the like) that are rotatably supported by the bearings and that are arranged coaxially with a rotation center of a rotor of an electric motor, and an eccentric portion that is provided between the center shaft portions. Furthermore, the roller mounted on the eccentric portion is mounted on the eccentric portion after the center shaft portion is passed therethrough. Thus, in the rotary compressors described in Patent Literature 1, Patent Literature 2, and Patent Literature 5, a crankshaft is formed such that an outer circumference surface on a counter-eccentric side of the eccentric portion (the outer circumference surface of the eccentric portion that is on the opposite side of the direction of eccentricity) is formed outside a periphery of the center shaft portion in order to mount the inner roller to the eccentric portion. That is, in the rotary compressors described in Patent Literature 1, Patent Literature 2, and Patent Literature 5, the diameter of the eccentric portion needs to be disadvantageously large in order to increase the eccentricity of the eccentric portion. However, an end face of the eccentric portion in the central axis direction slides, for example, with the sub bearing, which occludes the opening portions of the cylinder chamber. Accordingly, when attempting to increase the eccentricity of the eccentric portion of the crankshaft, the rotary compressors described in Patent Literature 1, Patent Literature 2, and Patent Literature 5 encounter a problem in that the efficiency of the rotary compressor is reduced due to increase in sliding loss at the eccentric portion.

[0011]

In the rotary compressor described in Patent Literature 4, assuming that the radius of the main shaft (corresponding to the main shaft portion radius in Patent Literature 4) is Rm, the eccentric portion radius is Re, and the eccentric portion eccentricity is e, then, Re < Rm + e holds true. That is, in the rotary compressor described in Patent Literature 4, the crankshaft is formed such that the outer circumference surface on the counter-eccentric side of the eccentric portion is inside (on the center shaft side of the eccentric portion) the periphery of the main shaft. However, in the rotary compressor described in Patent Literature 4, assuming that the radius of the sub shaft (corresponding to the sub shaft portion radius in Patent Literature 4) is Rs, then, Re > Rs + e holds true. That is, similar to the rotary compressors described in Patent Literature 1, Patent Literature 2, and Patent Literature 5, in the rotary compressor described in Patent Literature 4, the crankshaft is formed such that the outer circumference surface on the counter-eccentric side of the eccentric portion is outside the periphery of the sub shaft (the center shaft portion that is to be inserted into the inner roller). Thus, similar to the rotary compressors described in Patent Literature 1, Patent Literature 2, and Patent Literature 5, in the rotary compressor described in Patent Literature 4, the diameter of the eccentric portion also needs to be disadvantageously large after all in order to increase the eccentricity of the eccentric portion. Accordingly, when attempting to increase the eccentricity of the eccentric portion of the crankshaft, the rotary compressor described in Patent Literature 4 also encounters a problem in that the efficiency of the rotary compressor is reduced due to increase in the sliding loss at the eccentric portion.

[0012]

As for the rotary compressor described in Patent Literature 3, a relief for moving rings constituting the roller to the radial direction is formed at the boundary with the eccentric portion of the center shaft portion. Accordingly, in the rotary compressor described in Patent Literature 3, the rings constituting the roller can be mounted on the eccentric portion even when employing a crankshaft in which the outer circumferential surface on the counter-eccentric side of the eccentric portion is formed inside (on the central axis side of the eccentric portion) the periphery of the center shaft portion, that is, even when the eccentricity is increased without increasing the diameter of the eccentric portion

[0013]

Now, in a rotary compressor, a roller carries out eccentric rotational motion inside a cylinder chamber. As such, in order to prevent wear of the end faces of the roller, clearances are formed between the roller and the components (a main bearing, a sub bearing, a partition plate, and the like) that occlude the opening portions of the cylinder chamber. Furthermore, the amount of each of these clearances needs to be appropriate in order to suppress refrigerant leakage from the clearances.

[0014]

However, in the rotary compressor described in Patent Literature 3, the roller is constituted by ring bodies that are stacked in the central axis direction of the eccentric portion. Accordingly, in the rotary compressor described in Patent Literature 3, accuracy in the roller height (the length in the central axis direction of the eccentric portion) becomes poor and, thus, it is difficult to secure appropriate clearances between the roller and the components that occlude the opening portions of the cylinder chamber. As such, the rotary compressor described in Patent Literature 3 has a problem in that the end faces of the roller become worn out. Furthermore, there is a problem in that the efficiency of the rotary compressor is reduced due to increase in refrigerant leakage loss caused by refrigerant leakage from between the roller and the components that occlude the opening portions of the cylinder hamber. Additionally, in the rotary compressor described in Patent Literature 3, the outer circumferential surface of the roller becomes disadvantageously uneven due to, for example, variation in the outer diameter dimension of each ring body. Accordingly, in the rotary compressor described in Patent Literature 3, there is also a problem in that the efficiency of the rotary compressor is reduced due to increase in refrigerant leakage loss caused by refrigerant leakage from between the outer circumferential surface of the roller and the vane.

[0015]

The invention has been made in order to solve the problems described above and an object thereof is to provide a highly efficient rotary compressor that is capable of suppressing sliding loss at the eccentric portion, wear of the roller, and refrigerant leakage loss occurring in the vicinity of the roller even when the eccentricity of the eccentric portion is increased.

[Solution to Problem]

[0016]
A rotary compressor according to the invention includes an electric motor including a stator and a rotor; a crankshaft including a plurality of center shaft portions arranged coaxially with a rotation center of the rotor and at least one eccentric portion provided between the center shaft portions, the at least one eccentric portion being arranged on a central axis that is eccentric with respect to a central axis of the center shaft portions, wherein one end of the center shaft portions is fixed to the rotor; a compression mechanism provided with, in the same number as the number of the at least one eccentric portion, a roller rotatably mounted on the at least one eccentric portion, a cylinder formed with a cylindrical cylinder chamber, the cylinder being arranged with the at least one eccentric portion and the roller in the cylinder chamber, and a vane that divides an inside of the cylinder chamber into two spaces that are a compression chamber and a suction chamber; and a hermetic vessel that houses the electric motor, the crankshaft, and the compression mechanism, in which at least one of the rollers includes an inner circumferential side roller that is rotatably provided to an outer circumferential surface of the at least one eccentric portion, and a single-piece outer circumferential side roller that is provided to an outer circumferential surface of the inner circumferential side roller, the inner circumferential side roller has a plurality of ring bodies parted in a central axis direction of the at least one eccentric portion, an outer circumferential surface on a counter-eccentric side of the at least one eccentric portion is formed closer to the central axis side of the at least one eccentric portion than an outer circumferential surface of the center shaft portions, and a relief for moving the ring bodies towards a direction of eccentricity of the at least one eccentric portion is formed on at least one side of two edges of the at least one eccentric portion and in a center shaft portion at the boundary with the at least one eccentric portion.

[Advantageous Effects of Invention]

[0017]

A rotary compressor according to the invention includes a roller having an inner circumferential side roller and an outer circumferential side roller. Furthermore, the inner circumferential side roller includes a plurality of ring bodies that has been divided in a central axis direction of an eccentric portion. Furthermore, a crankshaft of the rotary compressor according to the invention is formed with a relief, in the central axis at a boundary with the eccentric portion, for moving the ring bodies to a direction of eccentricity of the eccentric portion. Accordingly, in the rotary compressor according to the invention, the ring bodies constituting the inner circumferential side roller can be mounted on the eccentric portion even when the outer circumferential surface on the counter-eccentric side of the eccentric portion is formed more on the center shaft side of the eccentric portion with respect to the outer circumferential surface of the center shaft portion, that is, even when the eccentricity of the eccentric portion is increased without increasing the diameter of the eccentric portion. Accordingly, the rotary compressor according to the invention is capable of suppressing sliding loss at the eccentric portion even when the eccentricity of the eccentric portion is increased.

[0018]

Furthermore, in the rotary compressor according to the invention, a single-piece outer circumferential side roller is provided to the outer circumferential surface of the inner circumferential side roller. Accordingly, with the outer circumferential side roller, the rotary compressor according to the invention can obtain accuracy in the roller height and, further, suppress unevenness of the roller outer circumferential surface. The rotary compressor according to the invention can thus suppress wear of the roller and refrigerant leakage loss occurring in the vicinity of the roller.

[0019]

Therefore, the invention can provide a highly efficient rotary compressor even when the eccentricity of the eccentric portion is increased.

[Brief Description of Drawings]

[0020]

[Fig. 1] Fig. 1 is a longitudinal sectional view illustrating a rotary compressor according to Embodiment 1 of the invention.

[Fig. 2] Fig. 2 is an enlarged view (longitudinal sectional view) of a main section illustrating a vicinity of an eccentric portion of the rotary compressor according to Embodiment 1 of the invention.

[Fig. 3] Fig. 3 illustrates explanatory diagrams for describing an assembling process of a typical compression mechanism.

[Fig. 4] Fig. 4 is an explanatory diagram for describing an assembling process of the typical compression mechanism subsequent to Fig. 3.

[Fig. 5] Fig. 5 is an explanatory diagram for describing an assembling process of the typical compression mechanism subsequent to Fig. 4.

[Fig. 6] Fig. 6 is an explanatory diagram for describing an assembling process of the typical compression mechanism subsequent to Fig. 5.

[Fig. 7] Fig. 7 is an explanatory diagram for describing an assembling process of the typical compression mechanism subsequent to Fig. 6.

[Fig. 8] Fig. 8 is an explanatory diagram for describing an assembling process of the typical compression mechanism subsequent to Fig. 7.

[Fig. 9] Fig. 9 is an explanatory diagram for describing an assembling process of the typical compression mechanism subsequent to Fig. 8.

[Fig. 10] Fig. 10 is an explanatory diagram illustrating a state in which a single-piece roller is being assembled to the crankshaft according to Embodiment 1 of the invention.

[Fig. 11] Fig. 11 illustrates explanatory diagrams for describing a process of assembling an upper roller and a lower roller according to Embodiment 1 of the invention to the crankshaft according to Embodiment 1 of the invention.

[Fig. 12] Fig. 12 is a plan view illustrating an example of a roller according to Embodiment 3 of the invention.

[Fig. 13] Fig. 13 is a plan view illustrating another example of a roller according to Embodiment 3 of the invention.

[Fig. 14] Fig. 14 is an enlarged view (longitudinal sectional view) of a main section illustrating a vicinity of an eccentric portion of a rotary compressor according to Embodiment 4 of the invention.

[Fig. 15] Fig. 15 is an explanatory diagram for describing an assembling method of an upper roller and a lower roller to a crankshaft according to Embodiment 4.

[Fig. 16] Fig. 16 is an explanatory diagram for describing the assembling method of the upper roller and the lower roller to the crankshaft according to Embodiment 4 subsequent to Fig. 15.

[Fig. 17] Fig. 17 is an explanatory diagram for describing the assembling method of the upper roller and the lower roller to the crankshaft according to Embodiment 4 subsequent to Fig. 16.

[Fig. 18] Fig. 18 is an explanatory diagram for describing the assembling method of the upper roller and the lower roller to the crankshaft according to Embodiment 4 subsequent to Fig. 17.

[Fig. 19] Fig. 19 is an explanatory diagram for describing the assembling method of the upper roller and the lower roller to the crankshaft according to Embodiment 4 subsequent to Fig. 18.

[Description of Embodiments]

[0021]

Embodiment 1

Fig. 1 is a longitudinal sectional view illustrating a rotary compressor according to Embodiment 1 of the invention. Furthermore, Fig. 2 is an enlarged view (longitudinal sectional view) of a main section illustrating a vicinity of an eccentric portion of this rotary compressor.

A rotary compressor 100 houses, inside a hermetic vessel 1, an electric motor unit 2 that includes a stator 2a and a rotor 2b, and a compression mechanism 3 that is driven by the electric motor unit 2. The torque of the electric motor unit 2 is transmitted to the compression mechanism 3 through a crankshaft 4. Furthermore, lubricant oil (refrigerating machine oil) that lubricates the compression mechanism 3 is retained inside the hermetic vessel 1.

[0022]

The crankshaft 4 includes a main shaft 4a that is fixed to the rotor 2b of the electric motor unit 2, a sub shaft 4b that is provided on the opposite side of the main shaft 4a, a main shaft side eccentric portion 4c and a sub shaft side eccentric portion 4d that are provided between the main shaft 4a and the sub shaft 4b with a predetermined phase difference (for example, 180 degrees), and an intermediate shaft 4e that is provided between the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d.
Note that the main shaft 4a, the sub shaft 4b, and the intermediate shaft 4e are arranged coaxially with the rotation center of the rotor 2b of the electric motor unit 2 and correspond to "center shaft portions" of the invention.

[0023]

Furthermore, in Embodiment 1, the shape of the crankshaft 4 is formed as illustrated in Fig. 2. Specifically, in Embodiment 1, the eccentricities of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d are increased without increasing the diameters of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. Accordingly, in the crankshaft 4, an outer circumference surface on a counter-eccentric side of the main shaft side eccentric portion 4c and an outer circumference surface on a counter-eccentric side of the sub shaft side eccentric portion 4d (the outer circumference surface of each of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d that are on the opposite side with respect to the direction of eccentricity) are each formed inside (more to the central axis side of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d) the periphery of the center shaft portions (the main shaft 4a, the sub shaft 4b, and the intermediate shaft 4e).

[0024]

Furthermore, reliefs 4f and 4g are formed in the crankshaft 4 according to Embodiment 1 in order to allow an upper roller 10 and a lower roller 11 that are described later to be mounted on the crankshaft 4. The relief 4f is provided in the main shaft 4a at the boundary with the main shaft side eccentric portion 4c. This relief 4f includes an inclined surface that connects the outer circumferential surface of the main shaft 4a and the outer circumference surface on the counter-eccentric side of the main shaft side eccentric portion 4c. Furthermore, the relief 4g is provided in the sub shaft 4b at the boundary with the sub shaft side eccentric portion 4d. This relief 4g includes a stepped portion that is recessed from the outer circumferential surface of the sub shaft 4b towards the outer circumferential surface on the counter-eccentric side of the sub shaft side eccentric portion 4d.

[0025]

The crankshaft 4 structured as above is rotatably supported by a main bearing 5 and a sub bearing 6. Specifically, the main bearing 5 is provided at the upper portion of the compression mechanism 3 and rotatably supports the main shaft 4a of the crankshaft 4. Furthermore, the sub bearing 6 is provided at the lower portion of the compression mechanism 3 and rotatably supports the sub shaft 4b of the crankshaft 4.

[0026]

The compression mechanism 3 includes an upper cylinder 7 on the main shaft 4a side and a lower cylinder 8 on the sub shaft 4b side.

[0027]

The upper cylinder 7 has a cylindrical cylinder chamber. The cylinder chamber is provided with the upper roller 10 that is rotatably fitted to the main shaft side eccentric portion 4c of the crankshaft 4. Furthermore, the two end faces of the cylinder chamber of the upper cylinder 7 in the shaft direction are occluded by the main bearing 5 and a partition plate 9. The upper cylinder 7 is further provided with an upper vane 12 that carries out reciprocating motion in accordance with the rotation of the main shaft side eccentric portion 4c. This upper vane 12 partitions the inside of the cylinder chamber into a suction chamber and a compression chamber.

[0028]

The lower cylinder 8 also has a cylindrical cylinder chamber. The cylindrical chamber is provided with the lower roller 11 that is rotatably fitted to the sub shaft side eccentric portion 4d of the crankshaft 4. Furthermore, the two end faces of the cylinder chamber of the lower cylinder 8 in the shaft direction are occluded by the sub bearing 6 and the partition plate 9. The lower cylinder 8 is further provided with a lower vane 13 that carries out reciprocating motion in accordance with the rotation of the sub shaft side eccentric portion 4d. This lower vane 13 partitions the inside of the cylinder chamber into a suction chamber and a compression chamber.

[0029]

Now, in Embodiment 1, the upper roller 10 and the lower roller 11 are structured as illustrated in Fig. 2.
Specifically, the upper roller 10 includes an inner circumferential side roller 10b that is rotatably provided to the outer circumferential surface of the main shaft side eccentric portion 4c, and an outer circumferential side roller 10a that is provided to the outer circumferential surface of the inner circumferential side roller 10b. Furthermore, the inner circumferential side roller 10b includes a plurality of ring bodies 10c that has been divided in the central axis direction of the main shaft side eccentric portion 4c. In other words, the inner circumferential side roller 10b includes the plurality of ring bodies 10c that is stacked in the central axis direction of the main shaft side eccentric portion 4c. Furthermore, in Embodiment 1, the length of the outer circumferential side roller 10a in the central axis direction of the main shaft side eccentric portion 4c is greater than the length of the inner circumferential side roller 10b in the central axis direction of the main shaft side eccentric portion 4c. The clearance between each edge of the outer circumferential side roller 10a and the corresponding one of the main bearing 5 and the partition plate 9 is maintained at an appropriate amount. That is to say, the length of the outer circumferential side roller 10a in the central axis direction of the main shaft side eccentric portion 4c is somewhat smaller than the length of the upper cylinder 7 in the central axis direction of the main shaft side eccentric portion 4c.

[0030]

Furthermore, the lower roller 11 includes an inner circumferential side roller 11b that is rotatably provided to the outer circumferential surface of the sub shaft side eccentric portion 4d, and an outer circumferential side roller 11a that is provided to the outer circumferential surface of the inner circumferential side roller 11b. Furthermore, the inner circumferential side roller 11b includes a plurality of ring bodies 11c that has been divided in the central axis direction of the sub shaft side eccentric portion 4d. In other words, the inner circumferential side roller 11b includes the plurality of ring bodies 11c that is stacked in the central axis direction of the sub shaft side eccentric portion 4d. Furthermore, in Embodiment 1, the length of the outer circumferential side roller 11a in the central axis direction of the sub shaft side eccentric portion 4d is greater than the length of the inner circumferential side roller 11b in the central axis direction of the sub shaft side eccentric portion 4d. The clearance between each edge of the outer circumferential side roller 11a and the corresponding one of the sub bearing 6 and the partition plate 9 is maintained at an appropriate amount. That is to say, the length of the outer circumferential side roller 11a in the central axis direction of the sub shaft side eccentric portion 4d is somewhat smaller than the length of the lower cylinder 8 in the central axis direction of the sub shaft side eccentric portion 4d.

[0031]

In the compression mechanism 3 structured as above, the upper cylinder 7 and the main bearing 5 that are fixed by bolting and the lower cylinder 8 and the sub bearing 6 that are fixed by bolting sandwiches the partition plate 9. Furthermore, these components are fixed and secured with bolts that are inserted from the outer side of the main bearing 5 to the lower cylinder 8 and with bolts that are inserted from the outer side of the sub bearing 6 to the upper cylinder 7.

[0032]

A bolt 14 depicted in Fig. 1 is a portion of a bolt that is inserted from the outer side of the main bearing 5 to the lower cylinder 8 and that fastens the components.

[0033]

Furthermore, a bolt 15 depicted in Fig. 1 is a portion of a bolt that fastens the lower cylinder 8 and the sub bearing 6 together.

[0034]

In the rotary compressor 100 structured as such, the rotation of the rotor 2b rotates the crankshaft 4 that is fitted to the rotor 2b. Accordingly, the upper roller 10 that is rotatably mounted on the main shaft side eccentric portion 4c of the crankshaft 4 carries out eccentric rotary motion inside the cylinder chamber of the upper cylinder 7. Similarly, the lower roller 11 that is rotatably mounted on the sub shaft side eccentric portion 4d of the crankshaft 4 carries out eccentric rotary motion inside the cylinder chamber of the lower cylinder 8. The eccentric rotary motion of the upper roller 10 and the lower roller 11 gradually reduces the volume of the compression chamber of the upper cylinder 7 and that of the lower cylinder 8, respectively; accordingly, refrigerant gas inside each of the compression chambers is compressed. The compressed a refrigerant gas is discharged into the hermetic vessel 1 and is then sent outside through a discharge pipe 23. Note that an accumulator 40 is provided adjacent to the hermetic vessel 1. This accumulator 40 is in communication with the cylinder chamber of the upper cylinder 7 and the cylinder chamber of the lower cylinder 8 through a suction connecting pipe 21 and a suction connecting pipe 22, respectively. That is, the refrigerant gas is sent to the cylinder chamber of the upper cylinder 7 and to the cylinder chamber of the lower cylinder 8 through the suction connecting pipe 21 and the suction connecting pipe 22, respectively.

[0035]

In a state in which the crankshaft 4 is mounted in the compression mechanism 3, the underside (the end face in the central axis direction) of the sub shaft side eccentric portion 4d of the crankshaft 4 is supported by the sub bearing 6 of the compression mechanism 3. Accordingly, the underside of the sub shaft side eccentric portion 4d slides against the sub bearing 6 during the refrigerant compression stroke. As such, if the diameter of the sub shaft side eccentric portion 4d is large, sliding loss between the two increases. However, in Embodiment 1, the eccentricity of the sub shaft side eccentric portion 4d is increased without increasing the diameter of the sub shaft side eccentric portion 4d. Accordingly, the rotary compressor 100 according to Embodiment 1 is capable of suppressing sliding loss between the underside of the sub shaft side eccentric portion 4d and the sub bearing 6.

[0036]

Furthermore, suppression of increase in the diameter of the sub shaft side eccentric portion 4d allows the sliding length between the outer circumferential surface of the sub shaft side eccentric portion 4d and the inner circumferential surface of the lower roller 11 to be suppressed. Accordingly, an advantage can be gained in that the sliding loss between the outer circumferential surface of the sub shaft side eccentric portion 4d and the lower roller 11 (more specifically, the inner circumferential side roller 11b) can be suppressed. In Embodiment 1, the eccentricity of the main shaft side eccentric portion 4c is also increased without increasing its diameter. Accordingly, an advantage can be gained in that the sliding loss between the outer circumferential surface of the main shaft side eccentric portion 4c and the upper roller 10 (more specifically, the inner circumferential side roller 10b) can be suppressed.

[0037]

Furthermore, in Embodiment 1, the clearance between each edge of the outer circumferential side roller 10a and the corresponding one of the main bearing 5 and the partition plate 9 is maintained at an appropriate amount; thus, it is possible to suppress refrigerant leakage loss occurring at each of the two clearances and to suppress wear of the edges of the outer circumferential side roller 10a. Similarly, the clearance between each edge of the outer circumferential side roller 11a and the corresponding one of the sub bearing 6 and the partition plate 9 is maintained at an appropriate amount; thus, it is possible to suppress refrigerant leakage loss occurring at each of the two clearances and to suppress wear of the edges of the outer circumferential side roller 11a.

[0038]

Subsequently, an assembling process of the compression mechanism 3 according to Embodiment 1 will be described. Note that the assembling process of a typical compression mechanism (a compression mechanism provided with a single-piece roller) will be first described with reference to Figs. 3 to 9 in order to facilitate understanding of the advantage of the rotary compressor 100 according to Embodiment 1. Then, an assembling process of the compression mechanism 3 according to Embodiment 1 will be described while referring to the assembling process of the typical compression mechanism.

Note that components of the typical compression mechanism that have the same functions as the compression mechanism 3 of Embodiment 1 are denoted by same reference signs.

[0039]

The typical compression mechanism is assembled as follows.

(1) As illustrated in Fig. 3(a), the upper cylinder 7 and the main bearing 5 are first fixed and fastened together by bolts 16. A plurality of bolts 16 is used. As illustrated in Fig. 3(b), the main shaft 4a is passed through the upper roller 10 to assemble the upper roller 10 to the main shaft side eccentric portion 4c.

(2) As illustrated in Fig. 4, the main shaft 4a of the crankshaft 4 that is assembled with the upper roller 10 is inserted to the main bearing 5 from the upper cylinder 7 side. At this time, the upper vane 12 is incorporated into the upper cylinder 7 (not illustrated).

(3) As illustrated in Fig. 5, the sub shaft 4b and the sub shaft side eccentric portion 4d are passed through the partition plate 9 such that the partition plate 4e is assembled to the intermediate shaft 4e. As shown by an arrow, the sub shaft 4b and the sub shaft side eccentric portion 4d are, in this state, merely passed through the partition plate 9. Thus, the center of the partition plate 9 and the center of the upper cylinder 7 do not match each other.

(4) As illustrated in Fig. 6, the partition plate 9 is moved in a direction orthogonal to the shaft, and the partition plate 9 is set so that the center of the upper cylinder 7 and that of the partition plate 9 are aligned with each other. Furthermore, bolt through holes 9a provided in the partition plate 9, bolt through holes 7a of the upper cylinder 7, and bolt through holes 5a of the main bearing 5 are respectively made to align with each other. This is to allow the bolts 14 described later to be inserted therethrough.

(5) As illustrated in Fig. 7, the sub shaft 4b is passed through the lower roller 11. The lower roller 11 is then assembled to the sub shaft side eccentric portion 4d.

(6) As illustrated in Fig. 8, the lower cylinder 8 and the sub bearing 6 are fixed together with the bolts 15. Furthermore, the lower vane 13 is incorporated into the lower cylinder 8 (not illustrated). The sub shaft 4b of the crankshaft 4 is inserted through the sub bearing 6. Furthermore, bolt through holes 9b provided in the partition plate 9, bolt through holes 8b of the lower cylinder 8, and bolt through holes 6b of the sub bearing 6 are respectively made to align with each other. This is to allow the bolts 17 described later to be inserted therethrough.

(7) As illustrated in Fig. 9, the bolts 17 are inserted through from the outer side of the sub bearing 6 and are screwed into the female screw portion of the upper cylinder 7. As such, the lower cylinder 8 and the upper cylinder 7 are fixed so as to sandwich the partition plate 9 with the lower cylinder 8 and the upper cylinder 7. Similarly, the bolts 14 are inserted through from the outer side of the main bearing 5 and are screwed into the female screw portion of the lower cylinder 8. As such, the upper cylinder 7 and the lower cylinder 8 are fixed so as to sandwich the partition plate 9 with the upper cylinder 7 and the lower cylinder 8.

[0040]

Now, because the compression mechanism is assembled with the assembling process described above, when the shape of the crankshaft 4 according to Embodiment 1 is adopted to the conventional compression mechanism in which the upper roller 10 and the lower roller 11 are each formed as a single piece, a problem is encountered in that the upper roller 10 and the lower roller 11 cannot be assembled to the crankshaft 4. Specifically, in the crankshaft 4 according to Embodiment 1, the outer circumference surface on the counter-eccentric side of the main shaft side eccentric portion 4c and that of the sub shaft side eccentric portion 4d are each formed inside the periphery of the center shaft portions (the main shaft 4a, the sub shaft 4b, and the intermediate shaft 4e). As such, as illustrated in Fig. 10, when attempting to assemble the upper roller 10 to the main shaft side eccentric portion 4c, for example, the upper roller 10 needs to be inclined at the boundary between the main shaft 4a and the main shaft side eccentric portion 4c to assemble the upper roller 10 to the main shaft side eccentric portion 4c. However, if the upper roller 10 is a single piece roller, because the height of the upper roller is large, the inner circumferential surface of the upper roller 10 and the outer circumferential surface of the crankshaft 4 come in contact with each other, for example, at the circled parts in Fig. 10; thus, the upper roller 10 cannot be assembled to the main shaft side eccentric portion 4c. On the basis of a similar reason, the lower roller 11 cannot be assembled to the sub shaft side eccentric portion 4d.

[0041]

Accordingly, in Embodiment 1, the upper roller 10 and the lower roller 11 are structured as above such that the upper roller 10 and the lower roller 11 can be assembled to the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d, respectively. The details will be described below.

[0042]

Fig. 11 illustrates explanatory diagrams for describing a process of assembling the upper roller and the lower roller according to Embodiment 1 of the invention to the crankshaft according to Embodiment 1 of the invention.

[0043]

As shown in Fig. 11(a), the inner circumferential side roller 10b is first assembled to the main shaft side eccentric portion 4c when the upper roller 10 is assembled to the main shaft side eccentric portion 4c. Specifically, the main shaft 4a is passed through one of the ring bodies 10c that constitutes the inner circumferential side roller 10b. Next, the ring body 10c is inclined at the relief 4f and is moved towards the direction of eccentricity of the main shaft side eccentric portion 4c. Then, the inclination of the ring body 10c is returned to its original angle. Since the height of the ring body 10c (the length in the central axis direction of the main shaft side eccentric portion 4c) is small, interference between the inner circumferential surface of the ring body 10c and the outer circumferential surface of the crankshaft 4 can be prevented when returning the inclination of the ring body 10c to its original angle. Accordingly, by returning the inclination of the ring body 10c to its original angle, the ring body 10c can be assembled to the main shaft side eccentric portion 4c. By assembling the ring body 10c to the main shaft side eccentric portion 4c as above in a sequential manner, the inner circumferential side roller 10b can be assembled to the main shaft side eccentric portion 4c. This step of assembling the inner circumferential side roller 10b is carried out in step (1) described above.

[0044]

Furthermore, as shown in Fig. 11(a), the inner circumferential side roller 11b is first assembled to the sub shaft side eccentric portion 4d when the lower roller 11 is assembled to the sub shaft side eccentric portion 4d. Specifically, the sub shaft 4b is passed through one of the ring bodies 11c that constitutes the inner circumferential side roller 11b. Then, the ring body 11c is moved towards the direction of eccentricity of the sub shaft side eccentric portion 4d at the relief 4g, and the ring body 11c is assembled to the sub shaft side eccentric portion 4d. At this time, the relief 4g includes the step that is recessed from the outer circumferential surface of the sub shaft 4b towards the outer circumferential surface on the counter-eccentric side of the sub shaft side eccentric portion 4d; thus, there is no need to incline the ring body 11 c in particular if the height of the step is greater than the height of the ring body 11c. By assembling the ring body 11 c to the sub shaft side eccentric portion 4d as above in a sequential manner, the inner circumferential side roller 11b can be assembled to the sub shaft side eccentric portion 4d. This step of assembling the inner circumferential side roller 11b is carried out earlier than step (5) described above.

[0045]

Note that, as it can be understood from the assembling process of the ring bodies 11 c of the lower roller 11, the mounting of the ring bodies (ring bodies 10c and 11c) is facilitated when the relief is structured to have a step such as the relief 4g. Furthermore, the processing of the crankshaft 4 is facilitated when the relief is structured to have a step such as the relief 4g. However, the strength of the relief is increased when the relief is structured to have an inclined surface such as the relief 4f. Accordingly, the relief provided in the main shaft 4a, which is required to secure more strength than the sub shaft 4b, is made to have the shape of the relief 4f.

[0046]

As described above, the outer circumferential side roller 10a is assembled as illustrated in Fig. 11(b) after the inner circumferential side roller 10b is mounted on the main shaft side eccentric portion 4c. Specifically, after the main shaft 4a is passed through the outer circumferential side roller 10a, the outer circumferential side roller 10a is assembled to the outer circumferential surface of the inner circumferential side roller 10b. As such, a state illustrated in Fig. 11(c) is reached. At this time, the outer circumferential surface on the counter-eccentric side of the inner circumferential side roller 10b is formed outside the outer circumferential surface of the main shaft 4a. Accordingly, the outer circumferential side roller 10a can be assembled in a similar way as that of conventional ones; thus, no problem occurs during assembling even if the outer circumferential side roller 10a is formed as a single piece. This step is carried out in step (1) described above. ,

[0047]

Similarly, as illustrated in Fig. 11(b), the outer circumferential side roller 11a is assembled after the inner circumferential side roller 11b is mounted on the main sub shaft side eccentric portion 4d. Specifically, after the sub shaft 4b is passed through the outer circumferential side roller 11a, the outer circumferential side roller 11a is assembled to the outer circumferential surface of the inner circumferential side roller 11b. As such, a state illustrated in Fig. 11(c) is reached. At this time, the outer circumferential surface on the counter-eccentric side of the inner circumferential side roller 11b is formed outside the outer circumferential surface of the sub shaft 4b. Accordingly, the outer circumferential side roller 11a can be assembled in a similar way as that of conventional ones; thus, no problem occurs during assembling even if the outer circumferential side roller 11a is formed as a single piece. This step is carried out in step (5) described above.

[0048]

As above, in the rotary compressor 100 configured as in Embodiment 1, the lower roller 11 includes the inner circumferential side roller 11 b and the outer circumferential side roller 11a. Furthermore, the inner circumferential side roller 11 b includes the plurality of ring bodies 11 c that has been divided in the central axis direction of the sub shaft side eccentric portion 4d. Additionally, the crankshaft 4 of the rotary compressor 100 according to Embodiment 1 is formed with a relief 4g for moving the ring body 11c towards the direction of eccentricity of the sub shaft side eccentric portion 4d. Accordingly, in the rotary compressor 100 according to Embodiment 1, the ring bodies 11c constituting the inner circumferential side roller 11b can be mounted on the sub shaft side eccentric portion 4d even when the outer circumferential surface on the counter-eccentric side of the sub shaft side eccentric portion 4d is formed inside the outer circumferential surface of the sub shaft 4b, that is, even when the eccentricity of the sub shaft side eccentric portion 4d is increased without increasing the diameter of the sub shaft side eccentric portion 4d. Accordingly, the rotary compressor 100 according to Embodiment 1 is capable of suppressing sliding loss at the sub shaft side eccentric portion 4d even when the eccentricity of the sub shaft side eccentric portion 4d is increased. Furthermore, suppression of increase in the diameter of the sub shaft side eccentric portion 4d allows the sliding length between the outer circumferential surface of the sub shaft side eccentric portion 4d and the inner circumferential surface of the lower roller 11 to be suppressed and, thus, also allows the sliding loss between the two to be suppressed.

[0049]

Furthermore, although the sliding loss described above does not occur at the edge of the main shaft side eccentric portion 4c, in Embodiment 1, the structure of the main shaft 4a, the main shaft side eccentric portion 4c, and the upper roller 10 are devised to have a similar structure to that of the sub shaft 4b, sub shaft side eccentric portion 4d, and the lower roller 11, respectively. That is, similar to the sub shaft side eccentric portion 4d, the eccentricity of the main shaft side eccentric portion 4c is increased without increasing its diameter. Accordingly, the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d are axisymmetric about the center shaft portions (the main shaft 4a, the sub shaft 4b, and the intermediate shaft 4e) of the crankshaft 4, and, thus, vibration and the like caused by the rotation and the like of the crankshaft 4 can be suppressed. Furthermore, suppression of increase in the diameter of the main shaft side eccentric portion 4c allows the sliding length between the outer circumferential surface of the main shaft side eccentric portion 4c and the inner circumferential surface of the upper roller 10 to be suppressed and, thus, also allows the sliding loss between the two to be suppressed.

[0050]

Furthermore, in the rotary compressor 100 according to Embodiment 1, the outer circumferential surface of each of the inner circumferential side rollers 10b and 11b is respectively provided with the single-piece outer circumferential surface rollers 10a and 11a. Accordingly, each edge of the outer circumferential side roller 10a and the corresponding one of the main bearing 5 and the partition plate 9 is maintained with an appropriate clearance; thus, it is possible to suppress refrigerant leakage loss occurring at each of the two clearances and to suppress wear of the edges of the outer circumferential side roller 10a. Similarly, each edge of the outer circumferential side roller 11a and the corresponding one of the sub bearing 6 and the partition plate 9 is maintained with an appropriate clearance; thus, it is possible to suppress refrigerant leakage loss occurring at each of the two clearances and to suppress wear of the edges of the outer circumferential side roller 11a.

[0051]

Furthermore, in the rotary compressor 100 according to Embodiment 1, the outer circumferential surface of the inner circumferential side rollers 10b and 11b are provided with the single-piece outer circumferential side rollers 10a and 11a, respectively; thus, unevenness of the outer circumferential surface of the upper roller 10 and the lower roller 11 can be suppressed. Accordingly, the rotary compressor 100 according to Embodiment 1 can suppress refrigerant leakage loss due to refrigerant leakage between the outer circumferential side roller 10a and the upper vane 12 and refrigerant leakage between the outer circumferential side roller 11a and the lower vane 13.

[0052]

As such, the rotary compressor 100 of Embodiment 1 can be devised as a rotary compressor with high efficiency.

[0053]

Note that while the shape of the relief 4f and the relief 4g are described to have different shapes in Embodiment 1, it goes without saying that the shapes may be the same.

[0054]

Furthermore, while the upper roller 10 and the lower roller 11 are mounted from different directions in Embodiment 1, the upper roller 10 and the lower roller 11 may be mounted from the same direction. For example, the upper roller 10 and the lower roller 11 may be assembled from the sub shaft 4b side. In this case, a relief may be formed in the sub shaft 4b at the boundary with the sub shaft side eccentric portion 4d, in the intermediate shaft 4e at the boundary with the sub shaft side eccentric portion 4d, and in the intermediate shaft 4e at the boundary with the main shaft side eccentric portion 4c.

[0055]

Furthermore, in Embodiment 1, while the invention has been described with an exemplary rotary compressor equipped with two cylinders, it goes without saying that a rotary compressor equipped with three or more cylinders or a rotary compressor equipped with only a single cylinder may embody the invention.

[0056]

Embodiment 2

In the upper roller 10, the outer circumferential side roller 10a can move to a certain degree in the up, down, left, and right directions due to the clearance between the outer circumferential surface of the outer circumferential side roller 10a and the inner circumferential surface of the cylinder chamber of the upper cylinder 7, the clearance between the outer circumferential side roller 10a and each of the main bearing 5 and the partition plate 9, and the like. Furthermore, due to the clearance between the outer circumferential surface of the inner circumferential side roller 10b and the inner circumferential surface of the main shaft side eccentric portion 4c, the clearance between the inner circumferential side roller 10b and each of the main bearing 5 and the partition plate 9, and the like, the inner circumferential side roller 10b can also move to a certain degree in the up, down, left, and right directions. Thus, when the movement of each of the outer circumferential side roller 10a and the inner circumferential side roller 10b becomes excessively large, there may be a case in which, during the operation of the rotary compressor 100, the inner circumferential side roller 10b (more specifically, the ring bodies 10c) may tilt at the inner circumferential surface side of the outer circumferential side roller 10a causing the outer circumferential side roller 10a to be disadvantageously fixed to the main shaft side eccentric portion 4c. If the outer circumferential side roller 10a is disadvantageously fixed to the main shaft side eccentric portion 4c, the rotation speed of the outer circumferential surface of the outer circumferential side roller 10a disadvantageously increases. As such, concerns arise such as sliding loss between the upper vane 12 and the outer circumferential surface of the outer circumferential side roller 10a, damage of the outer circumferential surface of the outer circumferential side roller 10a due to sliding between the upper vane 12 and the outer circumferential surface of the outer circumferential side roller 10a, seizing between the upper vane 12 and the outer circumferential side roller 10a, and the like.

Similar concerns also arise in the lower roller 11.

[0057]

Thus, in Embodiment 2, the inner circumferential side roller 10b is press-fitted into the outer circumferential side roller 10a when the upper roller 10 is assembled. Similarly, the inner circumferential side roller 11b is press-fitted into the outer circumferential side roller 11a when the lower roller 11 is assembled.

[0058]

By assembling the upper roller 10 as in Embodiment 2, the inner circumferential side roller 10b can be prevented from tilting at the inner circumferential surface side of the outer circumferential side roller 10a and, thus, the outer circumferential side roller 10a can be prevented from becoming fixed to the main shaft side eccentric portion 4c. Accordingly, sliding loss between the upper vane 12 and the outer circumferential surface of the outer circumferential side roller 10a, damage of the outer circumferential surface of the outer circumferential side roller 10a due to sliding between the upper vane 12 and the outer circumferential surface of the outer circumferential side roller 10a, seizing between the upper vane 12 and the outer circumferential side roller 10a, and the like can be prevented.

[0059]

Similarly, by assembling the lower roller 11 as in Embodiment 2, the inner circumferential side roller 11b can be prevented from tilting at the inner circumferential surface side of the outer circumferential side roller 11a and, thus, the outer circumferential side roller 11a can be prevented from becoming fixed to the sub shaft side eccentric portion 4d. Accordingly, sliding loss between the lower vane 13 and the outer circumferential surface of the outer circumferential side roller 11a, damage of the outer circumferential surface of the outer circumferential side roller 11a due to sliding between the lower vane 13 and the outer circumferential surface of the outer circumferential side roller 11a, seizing between the lower vane 13 and the outer circumferential side roller 11a, and the like can be prevented.

[0060]

Embodiment 3

The structure that can prevent the inner circumferential side rollers 10b and 11b from tilting at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a, respectively, is not limited to the structure described in Embodiment 2. By structuring each of the outer circumferential side rollers 10a and 11a and the corresponding inner circumferential side rollers 10b and 11b in an integrated and mobile manner, the arbitrary movement of the inner circumferential side rollers 10b and 11b become restricted at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a; thus, tilting of the inner circumferential side rollers 10b and 11b at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a, respectively, can be prevented.

In Embodiment 3, several exemplary structures, which can prevent the inner circumferential side rollers 10b and 11b from tilting at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a, respectively, will be illustrated.

[0061]

For example, the surface roughness of the outer circumferential surface of the inner circumferential side rollers 10b and 11b and that of the inner circumferential surface of the outer circumferential side rollers 10a and 11a may be rougher than the surface roughness of the inner circumferential surface of the inner circumferential side rollers 10b and 11 b and that of the outer circumferential surface of the outer circumferential side rollers 10a and 11a. As structured above, each of the outer circumferential side rollers 10a and 11a and the corresponding inner circumferential side rollers 10b and 11b become integrated and mobile, and the arbitrary movement of the inner circumferential side rollers 10b and 11b become restricted at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a; thus, tilting of the inner circumferential side rollers 10b and 11 b at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a, respectively, can be prevented.

[0062]

Furthermore, as illustrated in Fig. 12, the upper roller 10 may be formed such that recessed grooves 10d and 10e that extend in the central axis direction of the main shaft side eccentric portion 4c are formed in the outer circumferential surface of the inner circumferential side roller 10b and the inner circumferential surface of the outer circumferential side roller 10a, and such that a key 10f is provided between the recessed grooves 10d and 10e, for example. Additionally, the lower roller 11 may have a similar structure. Even structured as above, each of the outer circumferential side rollers 10a and 11a and the corresponding inner circumferential side rollers 10b and 11b are integrated and mobile, and the arbitrary movement of the inner circumferential side rollers 10b and 11b become restricted at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a; thus, tilting of the inner circumferential side rollers 10b and 11b at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a, respectively, can be prevented.

[0063]

Furthermore, as illustrated in Fig. 13, the outer circumferential surface of the inner circumferential side rollers 10b and 11b and the inner circumferential surface of the outer circumferential side rollers 10a and 11a may be formed with concaves and convexes, and the concaves and convexes of the outer circumferential surface of the inner circumferential side rollers 10b and 11b may be meshed with the concaves and convexes of the inner circumferential surface of the outer circumferential side rollers 10a and 11a, respectively, for example. Even structured as above, each of the outer circumferential side rollers 10a and 11a and the corresponding inner circumferential side rollers 10b and 11b are integrated and mobile, and the arbitrary movement of the inner circumferential side rollers 10b and 11b become restricted at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a; thus, tilting of the inner circumferential side rollers 10b and 11b at the inner circumferential surface side of the outer circumferential side rollers 10a and 11a, respectively, can be prevented.

[0064]

Embodiment 4

As described above, the rotor 2b of the electric motor unit 2 is mounted on the main shaft 4a of the crankshaft 4. As such, with the rotation of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d, centrifugal force acts on the main shaft 4a. When the main shaft 4a is bent by the bending moment caused by the centrifugal force, there may be cases in which whirling of the rotor 2b is caused. As a result, exciting force of the compression mechanism 3 and the electric motor unit 2 become large leading to cases in which vibration and noise become large. Accordingly, there may be cases in which the main shaft 4a of the crankshaft 4 needs to be configured to be thick in order to prevent the above kind of whirling. However, if the main shaft 4a is configured to be thick, the outer circumferential surface on the counter-eccentric side of the inner circumferential side roller 10b will be disposed inside the outer circumferential surface of the main shaft 4a. As such, there may be cases in which the outer circumferential side roller 10a cannot be assembled from the main shaft 4a side. In such cases, the crankshaft 4 may be configured as below. Note that in Embodiment 4, structures not stated in particular are the same as those in Embodiments 1 to 3.

[0065]

Fig. 14 is an enlarged view (longitudinal sectional view) of a main section illustrating a vicinity of the eccentric portion of the rotary compressor according to Embodiment 4 of the invention.

As illustrated in Fig. 14, in the crankshaft 4 according to Embodiment 4, the outer diameter of the main shaft 4a is larger than the outer diameter of the sub shaft 4b with the aim to, for example, prevent whirling of the rotor 2b. Furthermore, the dimension of each of the crankshaft 4 and the rollers (upper roller 10 and the lower roller 11) is defined as in the following expressions (1) to (6).

[0066]

Specifically, when defining R as the radius of the main shaft 4a, r as the radius of the sub shaft 4b, e as the eccentricity of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d, Re as the radius of the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d, rm as the radius of the intermediate shaft 4e, and Ri as the radius of the periphery of the inner circumferential side rollers 10b and 11b, then the following hold true.

Rc-e r -(5)

Ri - e > rm -(6)

[0067]

That is, as it can be understood from expressions (1) to (3), similar to Embodiment 1 to Embodiment 3, in the crankshaft 4 according to Embodiment 4, the outer circumference surface on the counter-eccentric side of the main shaft side eccentric portion 4c and that of the sub shaft side eccentric portion 4d are each formed inside the outer circumferential surface of the center shaft portions (the main shaft 4a, the sub shaft 4b, and the intermediate shaft 4e). Furthermore, as it can be understood from expressions (5) and (6), similar to Embodiment 1 to Embodiment 3, in the crankshaft 4 according to Embodiment 4, each of the outer circumference surface on the counter-eccentric side of the inner circumferential side rollers 10b and 11b is formed outside the outer circumferential surface of the sub shaft 4b and that of the intermediate shaft 4e.

[0068]

However, in the crankshaft 4 according to Embodiment 4, as described above, the outer diameter of the main shaft 4a is larger than the outer diameter of the sub shaft 4b, thus, as it can be understood from expression (4), each of the outer circumference surface on the counter-eccentric side of the inner circumferential side rollers 10b and 11b is positioned inside the outer circumferential surface of the main shaft 4a. Accordingly, different from Embodiment 1 to Embodiment 3, in the crankshaft 4 according to Embodiment 4, the outer circumferential side rollers 10a and 11a cannot be assembled from the main shaft 4a side. As such, in Embodiment 4, the outer circumferential side rollers 10a and 11a are configured to be assembled from the sub shaft 4b side.

[0069]

Note that when assembling the outer circumferential side roller 10a of the upper roller 10 from the sub shaft 4b side, as described below, the outer circumferential side roller 10a needs to be passed through the intermediate shaft 4e and needs to be moved in a substantially orthogonal direction with respect to the central axis of the intermediate shaft 4e. At this time, in Embodiment 4, a length Hm of the intermediate shaft 4e (the length of the intermediate shaft 4e in the central axis direction) is smaller than a height Ho of the outer circumferential side roller 10a (the length of the outer circumferential side roller 10a in the central axis direction). As such, in Embodiment 4, reliefs 4h and 4i for moving the outer circumferential side roller 10a in the substantially orthogonal direction with respect to the central axis of the intermediate shaft 4e are formed in the two ends of the intermediate shaft 4e at the boundary with the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. Specifically, the relief 4h is formed in the intermediate shaft 4e at the boundary with the sub shaft side eccentric portion 4d. Furthermore, the relief 4i is formed in the intermediate shaft 4e at the boundary with the main shaft side eccentric portion 4c. Note that the reliefs 4h and 4i may have a similar shape as that of the relief 4f, or may have a similar shape as that of the relief 4g.

[0070]

Details of a method of assembling the upper roller 10 and the lower roller 11 to the crankshaft 4 according to Embodiment 4 will be described below with reference to Figs. 15 to 19.

[0071]

As illustrated in Fig. 15, the inner circumferential side roller 10b (that is, the ring bodies 10c) is first assembled to the main shaft side eccentric portion 4c when the upper roller 10 is assembled to the main shaft side eccentric portion 4c. The assembling of the inner circumferential side roller 10b may be carried out from the main shaft 4a side or may be carried out from the sub shaft 4b side. If the inner circumferential side roller 10b is assembled from the sub shaft 4b side, there is no need in particular to provide the relief 4f.

[0072]

After the inner circumferential side roller 10b is assembled to the main shaft side eccentric portion 4c, as illustrated in Figs. 15 to 19, the outer circumferential side roller 10a is assembled. Specifically, as illustrated in Fig. 15, the outer circumferential side roller 10a is first inserted from the sub shaft 4b side to the intermediate shaft 4e. Then, as illustrated in Fig. 16, the inner circumferential side roller 10b that has been assembled beforehand is pushed up towards the main shaft 4a direction. This is because, since the length Hm of the intermediate shaft 4e is smaller than the height Ho of the outer circumferential side roller 10a, the outer circumferential side roller 10a needs to be tilted when the outer circumferential side roller 10a is moved towards the direction of eccentricity of the main shaft side eccentric portion 4c.

[0073]

As illustrated in Fig. 16, after the inner circumferential side roller 10b is pushed up towards the main shaft 4a direction, the outer circumferential side roller 10a is tilted such that the eccentric side of the main shaft side eccentric portion 4c moves towards the sub shaft 4b side and the counter-eccentric side of the main shaft side eccentric portion 4c moves towards the main shaft 4a side. At this time, in Embodiment 4, the relief 4h is formed in the intermediate shaft 4e at the boundary with the sub shaft side eccentric portion 4d. As such, a case such as the inner circumferential surface of the outer circumferential side roller 10a on the eccentric side of the main shaft side eccentric portion 4c becoming in contact with the outer circumferential surface of the intermediate shaft 4e such that the outer circumferential side roller 10a cannot be tilted can be prevented. Furthermore, in Embodiment 4, the relief 4i is formed in the intermediate shaft 4e at the boundary with the main shaft side eccentric portion 4c. As such, a case such as the inner circumferential surface of the outer circumferential side roller 10a on the counter-eccentric side of the main shaft side eccentric portion 4c becoming in contact with the outer circumferential surface of the intermediate shaft 4e such that the outer circumferential side roller 10a cannot be tilted can also be prevented. Tilting of the outer circumferential side roller 10a creates a space that allows the outer circumferential side roller 10a to be moved towards the direction of eccentricity of the main shaft side eccentric portion 4c.

[0074]

As illustrated in Fig. 17, after tilting the outer circumferential side roller 10a, the outer circumferential side roller 10a is moved towards the direction of eccentricity of the main shaft side eccentric portion 4c. Furthermore, as illustrated in Fig. 18, the inner circumferential side roller 10b that had been pushed up towards the main shaft 4a direction is lowered. Finally, as illustrated in Fig. 19, the outer circumferential side roller 10a is pushed up and is assembled to the inner circumferential side roller 10b. As such, the upper roller 10 can be assembled to the main shaft side eccentric portion 4c. This step is carried out in step (1) described in Embodiment 1.

[0075]

Note that the method described in Fig. 19 for assembling the lower roller 11 to the sub shaft side eccentric portion 4d is similar to that described in Embodiment 1.

[0076]

As described above, in the rotary compressor 100 according to Embodiment 4, the crankshaft 4 is structured as described above. As such, in addition to the advantages described in Embodiment 1 to Embodiment 3, an advantage can be gained in that the upper roller 10 and the lower roller 11 can be assembled to the crankshaft 4 even when the outer diameter of the main shaft 4a is increased with the aim to, for example, prevent whirling of the rotor 2b.

[0077]

Note that, in Embodiment 4, the reliefs 4h and 4i for moving the outer circumferential side roller 10a in the substantially orthogonal direction with respect to the central axis of the intermediate shaft 4e are formed in the two ends of the intermediate shaft 4e at the boundary with the main shaft side eccentric portion 4c and the sub shaft side eccentric portion 4d. However, the reliefs 4h and 4i are not required in particular when the length Hm of the intermediate shaft 4e is smaller than the height Ho of the outer circumferential side roller 10a and when the inner circumferential side roller 10b of the upper roller 10 is assembled from the main shaft 4a side. This is because the outer circumferential side roller 10a can be moved towards the direction of eccentricity of the main shaft side eccentric portion 4c without tilting the outer circumferential side roller 10a of the upper roller 10.

[0078]

Furthermore, in Embodiment 4, the invention has been described with an exemplary rotary compressor equipped with two cylinders. However, in a case of a rotary compressor equipped with only a single cylinder (a configuration with no intermediate shaft in the crankshaft), the advantages described in Embodiment 4 can be gained if the crankshaft is structured to satisfy the above expressions (1), (2), (4), and (5).

[Reference Signs List]

[0079]

1 hermetic vessel; 2 electric motor unit; 2a stator; 2b rotor; 3 compression mechanism; 4 crankshaft; 4a main shaft; 4b sub shaft; 4c main shaft side eccentric portion; 4d sub shaft side eccentric portion; 4e intermediate shaft; 4f relief; 4g relief; 4h relief; 4i relief; 5 main bearing; 5a bolt through hole; 6 sub bearing; 6b bolt through hole; 7 upper cylinder; 7a bolt through hole; 8 lower cylinder; 8b bolt through hole; 9 partition plate; 9a bolt through hole; 9b bolt through hole; 10 upper roller; 10a outer circumferential side roller; 10b inner circumferential side roller; 10c ring body; 10d, 10e recessed groove; 10f key; 11 lower roller; 11a outer circumferential side roller; 11b inner circumferential side roller; 11c ring body; 12 upper vane; 13 lower vane; 14 bolt; 15 bolt; 16 bolt; 17 bolt; 21 suction connecting pipe; 22 suction connecting pipe; 23 discharge pipe; 40 accumulator; 100 rotary compressor.

[Name of Document]

CLAIMS

[Claim 1]

A rotary compressor, comprising;

an electric motor including a stator and a rotor;

a crankshaft including a plurality of center shaft portions arranged coaxially with a rotation center of the rotor and at least one eccentric portion provided between the center shaft portions, the at least one eccentric portion being arranged on a central axis that is eccentric with respect to a central axis of the center shaft portions, one end of the center shaft portions being fixed to the rotor;

a compression mechanism provided with a roller rotatably mounted on the at least one eccentric portion, a cylinder formed with a cylindrical cylinder chamber, the cylinder being arranged with the at least one eccentric portion and the roller in the cylinder chamber, and a vane that divides an inside of the cylinder chamber into two spaces that are a compression chamber and a suction chamber, wherein a same number of the roller, the cylinder, and the vane as the at least one eccentric portion are provided; and

a hermetic vessel that houses the electric motor, the crankshaft, and the compression mechanism, wherein

the roller includes an inner circumferential side roller that is rotatably provided to an outer circumferential surface of the at least one eccentric portion, and a single-piece outer circumferential side roller that is provided to an outer circumferential surface of the inner circumferential side roller,

the inner circumferential side roller has a plurality of ring bodies parted in a central axis direction of the at least one eccentric portion,

an outer circumferential surface on a counter-eccentric side of the at least one eccentric portion is formed closer to the central axis side of the at least one eccentric portion than an outer circumferential surface of the center shaft portions, and

a relief for moving the ring bodies towards a direction of eccentricity of the at least one eccentric portion is formed on at least one side of two edges of the at least one eccentric portion and in the center shaft portions at a boundary of the at least one eccentric portion.

[Claim 2]

The rotary compressor of claim 1, wherein a length of the outer circumferential side roller in the central axis direction of the at least one eccentric portion is greater than a length of the inner circumferential side roller in the central axis direction of the at least one eccentric portion.

[Claim 3]

The rotary compressor of claim 1 or 2, wherein the center shaft portions include a main shaft that is assembled with the rotor and a sub shaft that is disposed on an opposite side of the main shaft with respect to the at least one eccentric portion, and

when defining R as a radius of the main shaft, r as a radius of the sub shaft, e as an eccentricity of the at least one eccentric portion, Re as a radius of the at least one eccentric portion, and Ri as a radius of a periphery of the inner circumferential side roller, then

Re - e < R, Re - e < r, Ri - e < R, and Ri - e > r hold true.

[Claim 4]

The rotary compressor of claim 3, wherein the eccentric portion of the crankshaft, the roller, the cylinder, and the vane comprise a plurality of eccentric portions, a plurality of rollers, a plurality of cylinders, and a plurality of vanes, respectively,
the center shaft portions include an intermediate shaft that is disposed between the eccentric portions, and

when defining rm as a radius of the intermediate shaft, then
Re - e < rm and Ri - e > rm hold true.

[Claim 5]

The rotary compressor of claim 4, wherein reliefs for moving the outer circumferential side roller are formed in two ends of the intermediate shaft at boundaries of the eccentric portions.

[Claim 6]

The rotary compressor of claim 4 or 5, wherein a length of the intermediate shaft is larger than a height of the outer circumferential side roller.

[Claim 7]

The rotary compressor of claim 1 or 2, wherein, in a state in which the inner circumferential side roller is provided to the at least one eccentric portion,

the outer circumferential surface on a counter-eccentric side of the inner circumferential side roller is arranged outside the outer circumferential surface of the center shaft portions.

[Claim 8]

The rotary compressor of claim 1 or 2, wherein the eccentric portion of the crankshaft, the roller, the cylinder, and the vane comprise a plurality of eccentric portions, a plurality of rollers, a plurality of cylinders, and a plurality of vanes, respectively.

[Claim 9]

The rotary compressor of any one of claims 1 to 8, wherein the relief includes an inclined surface that connects the outer circumferential surface of the center shaft portions and the outer circumferential surface on the counter-eccentric side of the at least one eccentric portion.

[Claim 10]

The rotary,compressor of any one of claims 1 to 8, wherein the relief includes a stepped portion that is recessed from the outer circumferential surface of the center shaft portions towards the outer circumferential surface on the counter-eccentric side of the at least one eccentric portion.

[Claim 11]

The rotary compressor of any one of claims 1 to 10, wherein the inner circumferential side roller is press-fitted into the outer circumferential side roller.

[Claim 12]

The rotary compressor of any one of claims 1 to 10, wherein the outer circumferential surface of the inner circumferential side roller and an inner circumferential surface of the outer circumferential side roller have a rougher surface roughness than a surface roughness of an inner circumferential surface of the inner circumferential side roller and an outer circumferential surface of the outer circumferential side roller.

[Claim 13]

The rotary compressor of any one of claims 1 to 10, wherein the outer circumferential surface of the inner circumferential side roller and an inner circumferential surface of the outer circumferential side roller are formed with concaves and convexes, and the concaves and convexes of the inner circumferential side roller and the concaves and convexes of the outer circumferential side roller are meshed together.

[Claim 14]

The rotary compressor of any one of claims 1 to 10, wherein the outer circumferential surface of the inner circumferential side roller and an inner circumferential surface of the outer circumferential side roller are each formed with a recessed groove that extends towards the central axis direction of the at least one eccentric portion, and

a key is provided between the recessed groove of the inner circumferential side roller and the recessed groove of the outer circumferential side roller.