FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
ROTARY COMPRESSOR
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION
AND THE MANNER IN WHICH IT IS TO BE PERFORMED
2
DESCRIPTION
Technical Field
[0001]
The present disclosure relates to a rotary compressor, and more 5 particularly, to
a fixing structure for a spring configured to push a vane onto a piston.
Background Art
[0002]
A related-art rotary compressor includes an annular cylinder, a piston
10 configured to rotate in a cylinder chamber formed in the cylinder, a vane configured to
move back and forth in a through-hole penetrating the cylinder in a radial direction,
and a spring configured to press the vane so that a distal end of the vane contacts the
outer peripheral surface of the piston. The spring is housed in a through-hole
formed radially inside the cylinder such that the spring can be compressed and
15 decompressed in the radial direction, and the end of the spring is held by being
screwed into a spiral groove formed on the inner surface of the through-hole (see, for
example, Patent Document 1).
Citation List
Patent Literature
20 [0003]
Patent Literature 1: Japanese Unexamined Patent Application Publication No.
2010-084575
Summary of Invention
Technical Problem
25 [0004]
In the rotary compressor disclosed in Patent Literature 1, an end of the spring
is required to be inserted into the helical groove on the inner surface of the throughhole
during assembly. However, Patent Literature 1 does not describe as to the
degree of easiness in insertion for screwing.
30 [0005]
3
In order to solve the above problem, the present disclosure aims at providing a
rotary compressor that realizes increased easiness in insertion of the spring for
screwing into the through-hole.
Solution to Problem
5 [0006]
A rotary compressor according to an embodiment of the present disclosure
includes a compression mechanism section configured to compress refrigerant. The
compression mechanism section includes an annular cylinder; a piston configured to
rotate inside a cylinder chamber in the cylinder; a vane configured to move back and
10 forth in a through-hole penetrating the cylinder in a radial direction; and a spring
configured to push the vane to make a distal end of the vane contact an outer surface
of the piston. The spring includes, at an end thereof opposite from the vane, an end
turn serving as a male thread, and the spring is fixed to the through-hole by the end
turn being screwed into a female thread on an inner surface of the through-hole.
15 The spring includes a handle portion formed by bending an end of the end turn
inwardly in an inner diameter direction of the spring.
Advantageous Effects of Invention
[0007]
According to an embodiment of the present disclosure, since the spring has a
20 handle portion, easiness in inserting the spring for screwing it into the through-hole
can be improved.
Brief Description of Drawings
[0008]
[Fig. 1] Fig. 1 is a schematic longitudinal sectional view of a rotary compressor
25 according to Embodiment 1 of the present disclosure.
[Fig. 2] Fig. 2 is a schematic cross-sectional view of a compression mechanism
section of the rotary compressor according to Embodiment 1 of the present
disclosure.
[Fig. 3] Fig. 3 illustrates a fixing structure for a spring of the rotary compressor
30 according to Embodiment 1 of the present disclosure.
4
[Fig. 4] Fig. 4 illustrates the spring in Fig. 3.
[Fig. 5] Fig. 5 illustrates an end turn of the spring in Fig. 3 when viewed from a
rear end of the spring.
[Fig. 6] Fig. 6 illustrates a fixing structure for the spring of the rotary
compressor according to Embodiment 2 of the present 5 disclosure.
Description of Embodiments
[0009]
A rotary compressor according to embodiments of the present disclosure will be
described below with reference to the drawings. Here, in the following drawings,
10 including Fig. 1, components with the same sign are the same or equivalent, which
are common throughout the entire description of the embodiment described below,
and the forms of the components in the entire specification are merely examples and
are not intended to be limiting.
[0010]
15 Embodiment 1
Fig. 1 is a schematic longitudinal sectional view of a rotary compressor
according to Embodiment 1 of the present disclosure. Fig. 2 is a schematic crosssectional
view of a compression mechanism section of the rotary compressor
according to Embodiment 1 of the present disclosure.
20 The rotary compressor is one of the components of the refrigerant circuit used
in heat pump equipment, such as air-conditioning apparatuses, refrigerators, freezers,
or water heaters, for example. The rotary compressor is a hermetically sealed
electric compressor, and has a structure in which a compression mechanism section
3 and an electric mechanism section 2 that drives the compression mechanism
25 section 3 via a rotating shaft 4 are arranged in a sealed container 1. The
compression mechanism section 3 is located in the lower part of the sealed container
1, and the electric mechanism section 2 is located in the upper part of the sealed
container 1. A space A is provided between the compression mechanism section 3
and the electric mechanism section 2. The rotary compressor in Embodiment 1 will
30 be described by using, as an example, a twin rotary compressor in which the
5
compression mechanism section 3 has two cylinders. However, the compressor
mechanism section 3 is not limited to this, and the compression mechanism section 3
may include one or three or more cylinders.
[0011]
The sealed container 1 includes a cylindrical center body 1a, 5 an upper body 1b,
and a lower body 1c, for example. The upper body 1b and the lower body 1c are
fitted into an upper opening and a lower opening of the center body 1a, respectively,
thereby sealing the interior of the sealed container 1. A discharge pipe 5 is
connected to the upper body 1b. The discharge pipe 5 is a connection pipe for
10 allowing high-temperature and high-pressure gas refrigerant inside the sealed
container 1 compressed by the compression mechanism section 3 to be discharged
into a refrigerant pipe.
[0012]
The sealed container 1 stores lubricating oil in the lower portion thereof. The
15 lubricating oil is pumped up by an oil supply mechanism (not shown) at a lower end of
the rotary shaft 4 and is supplied to each portion of the compression mechanism
section 3 to thereby keep it lubricated.
[0013]
The electric mechanism section 2 includes a stator 2a and a rotor 2b. The
20 rotor 2b is fixed to the rotary shaft 4, and rotation of the rotor 2b causes the rotary
shaft 4 to rotate, whereby rotating power is transmitted to the compression
mechanism section 3. The rotor 2b includes a gas hole 21 penetrating the rotor 2b
in a rotational axis direction. An air gap 22 is provided between the rotor 2b and the
stator 2a. The gas hole 21 and the air gap 22 serve as passages through which
25 refrigerant gas passes, and refrigerant gas discharged from the compression
mechanism section 3 moves above the electric mechanism section 2 through these
passages, and discharged to the outside from the discharge pipe 5.
[0014]
The compression mechanism section 3 includes a first compression
30 mechanism 30A, a second compression mechanism 30B, an upper bearing 40
6
disposed on an upper end face of the first compression mechanism 30A, a lower
bearing 50 disposed on a lower end face of the second compression mechanism 30B,
and an intermediate plate 60.
[0015]
The upper bearing 40 includes a hollow cylindrical bearing 5 portion 41 that
supports the rotary shaft 4 such that the rotary shaft 4 can rotate, and a flat annular
end plate 42 that closes an upper end face of a cylinder 31 (described later).
Likewise, the lower bearing 50 includes a hollow cylindrical bearing portion 51 that
supports the rotary shaft 4 such that the rotary shaft 4 can rotate, and a flat annular
10 end plate 52 that closes a lower end face of the cylinder 31 (described later). The
end plate 42 and the end plate 52 respectively include a discharge port 42a and a
discharge port 52a each provided with a discharge valve that opens under a
predetermined pressure or more inside a compression chamber (described later).
The end plate 42 and the end plate 52 respectively further include a muffler 43 and a
15 muffler 53 respectively covering the discharge port 42a and the discharge port 52a.
[0016]
Hereinbelow, a description will be made on configurations of the first
compression mechanism section 30A and the second compression mechanism
section 30B of the compression mechanism section 3. As the configurations of the
20 first compression mechanism section 30A and the second compression mechanism
section 30B are basically similar to each other, the following description illustrates the
first compression mechanism section 30A in particular.
[0017]
The first compression mechanism section 30A includes an annular cylinder 31
25 having a through-hole penetrating the cylinder 31 in the rotation axis direction, a
piston 32 rotating in a cylinder chamber formed in the cylinder 31 as described below,
a vane 33, and the like. The upper bearing 40 and the intermediate plate 60 are
located on both ends of the cylinder 31 in the rotational axial direction, and the
through-holes are closed by the end plate 42 of the upper bearing 40 and the
30 intermediate plate 60 to form a cylinder chamber 44 in the cylinder 31.
7
[0018]
The piston 32 is housed in the cylinder chamber 44 inside the cylinder 31 while
being engaged with an eccentric portion 4a of the rotary shaft 4 such that the piston
32 can rotate.
5 [0019]
The cylinder 31 includes a through-hole 34 penetrating the cylinder 31 in a
radial direction. The through-hole 34 communicates at its front end with the cylinder
chamber 44 and opens at its rear end in an outer surface of the cylinder 31. The
vane 33 is disposed in the through-hole 34 such that the vane 33 can move back and
10 forth in the radial direction. Inside the through-hole 34, a spring 35 is disposed
radially outside of the vane 33. The spring 35 pushes the vane 33 radially inwardly,
making a distal end 33b of the vane 33 always in contact with the piston 32. Due to
this contact between the distal end 33b of the vane 33 and the piston 32, the cylinder
chamber 44 is partitioned into a suction chamber 44a and a compression chamber
15 44b.
[0020]
The cylinder 31 further includes a suction port 36 and a discharge notch 37 that
are positioned with the vane 33 interposed therebetween. The suction port 36
penetrates the cylinder 31 in the radial direction. The discharge notch 37
20 communicates with the discharge port 42a in the end plate 42 of the upper bearing
40. An outlet pipe 73 of an accumulator 70 (described later) is connected to the
suction port 36 from the outside of the center body 1a of the sealed container 1.
Meanwhile, the discharge notch 37 communicates with the discharge port 42a in the
end plate 42 of the upper bearing 40.
25 [0021]
The second compression mechanism section 30B differs from the first
compression mechanism section 30A in that a through-hole formed at substantially
the center of the cylinder 31 of the second compression mechanism section 30B is
closed by the intermediate plate 60 and the lower bearing 50; the configuration of the
30 second compression mechanism section 30B is basically similar to that of the first
8
compression mechanism section 30A.
[0022]
The accumulator 70 has a container 71, an inlet pipe 72, an outlet pipe 73, and
an inner pipe 74 that communicates with the outlet pipe 73 inside 5 the container 71.
The accumulator 70 separates the refrigerant that flows into the container 71 from the
inlet pipe 72 into a liquid refrigerant and a gas refrigerant. The separated gas
refrigerant flows out of the container 71 through the inner tube 74 and flows into the
inlet chamber 44a of the cylinder chamber 44 from the inlet 36 of the cylinder 31
10 through the outlet tube 73.
[0023]
Hereinbelow, a description will be made on an operation of the rotary
compressor of Embodiment 1.
In the first compression mechanism section 30A, when electric power is
15 supplied to the electric mechanism section 2, the electric mechanism section 2
causes the rotation shaft 4 to rotate. As the rotating shaft 4 rotates, the eccentric
portion 4a of the rotating shaft 4 rotates eccentrically in the cylinder chamber 44, and
the piston 32 rotates eccentrically in the cylinder chamber 44. With the rotation of
the piston 32, gas refrigerant is suctioned from the accumulator 70 into the inlet
20 chamber 44a of the cylinder chamber 44 through the inlet 36. The suctioned gas
refrigerant is compressed as the volume of the compression chamber 44b is gradually
reduced with the rotation of the piston 32.
[0024]
Upon reaching a predetermined pressure, the compressed gas refrigerant is
25 discharged into an internal space B inside the muffler 43 from the discharge port 42a
of the upper bearing 40 through the discharge notch 37 of the cylinder 31. The gas
refrigerant discharged into the internal space B inside the muffler 43 is then
discharged into the space A inside the sealed container 1 from a discharge port (not
shown) of the muffler 43.
30 [0025]
9
In the second compression mechanism 30B, similarly, gas refrigerant suctioned
from the accumulator 70 is compressed and discharged into a space inside the
sealed container 1.
[0026]
In the first and second compression mechanism sections 5 30A and 30B,
suctioning and compression of gas refrigerant is repeated by rotation of the rotary
shaft 4. The gas refrigerant that is compressed in each of the first and second
compression mechanism sections 30A and 30B and discharged into the space inside
the sealed container reaches the upper part of the sealed container 1 through the
10 gaps formed in the electric mechanism section 2, namely the gas hole 21 and the air
gap 22, and is discharged from the discharge pipe 5 into the refrigerant circuit. In
this rotary compressor, for example, a flammable refrigerant such as R290 is used as
the refrigerant, but the type of refrigerant is not limited to this.
[0027]
15 A characteristic feature of Embodiment 1 resides in a fixing structure for the
spring 35. Hereinbelow, a description will be made on the fixing structure for the
spring 35. The first and second compression mechanism sections 30A, 30B have
this fixing structure in common. Thus, in this description, the fixing structure for the
spring 35 of the first compression mechanisms 30A will be specifically described.
20 [0028]
Fig. 3 shows the fixing structure for the spring of the rotary compressor
according to Embodiment 1 of the present disclosure. Fig. 4 shows the spring in Fig.
3. Fig. 5 shows an end turn of the spring in Fig. 3 when it is viewed from a rear end
of the spring.
25 [0029]
The spring 35 is made of elastic wire wound in a spiral shape. An end turn
35a, which is a rear end of the spring 35, has a larger diameter than the distal end
35b. A handle portion 35c is formed at the end of the end turn 35a. The handle
portion 35c is a bended portion that is formed by bending an end of the end turn 35a
30 inwardly in an inner diameter direction of the spring 35. A female threaded portion
10
34a is formed on the inner circumference of the through-hole 34 in the outer radial
direction where the spring 35 is placed, and the end turn 35a, which serves as the
male thread, is screwed into the female threaded portion 34a to fix the spring 35 to
the through-hole 34. The depth H of the female threaded portion 34a of the throughhole
34 is larger than the wire diameter J of the spring 35. The 5 diameter K of the
female threaded portion 34a is smaller than the diameter D of the end turn 35a of the
spring 35.
[0030]
Hereinbelow, a description will be made on functions of the handle portion 35c.
10 When fixing the spring 35 to the through-hole 34 during assembly, an operator
holds an outer periphery of the spring 35 and inserts the spring 35 into the throughhole
34 from radially outside. When the end turn 35a comes at a radial outer end of
the through-hole 34, for example, the operator puts his/her thumb and index finger
inside the spring 35 to hold the handle portion 35c. The operator then rotates the
15 handle portion 35c while holding it to thereby rotate the spring 35 and screw the end
turn 35a into the female thread 34a, and as a result, the spring 35 is fixed to the
through-hole 34. In this way, the handle portion 35c of the spring 35 provides
increased easiness in inserting the spring 35 for rotation and inserting the end turn
35a into the female thread 34a.
20 [0031]
As described above, since the handle portion 35c is provided to the end turn
35a of the spring 35, Embodiment 1 increases easiness in inserting the spring 35 for
screwing thereof into the female thread 34a.
[0032]
25 Embodiment 2
Embodiment 2 relates to positioning of the spring 35 when it is inserted. The
following description focuses on differences between Embodiment 2 and Embodiment
1.
[0033]
30 Fig. 6 shows a fixing structure for the spring of the rotary compressor according
11
to Embodiment 2 of the present disclosure.
Since the spring 35 is fixed by screwing the end turn 35a into the female thread
34a, an insertion depth L1 by which the end turn 35a of the spring 35 is inserted into
the through-hole 34 is restricted by a depth L2 of the female thread 34a in the radial
direction. In other words, a maximum value of the insertion depth 5 L1 equals to the
depth L2 of the female thread 34a. Hence, the insertion depth L1 of the spring 35
can be restricted by restricting the depth L2 of the female thread 34a.
[0034]
A deformation amount of the spring 35 in operation is determined depending on
10 an inner diameter of the cylinder, an outer diameter of the piston, and a length of the
vane. As mentioned above, the deformation amount of the spring 35 in operation is
predetermined, and a length and a spring constant of the spring 35 are selected
taking into account such deformation amount. Therefore, if the spring 35 is inserted
into the through-hole 34 deeper than needed, or in other words, if the insertion depth
15 L1 is too long, the spring 35 would be disposed inside the through-hole 34 while being
compressed more than needed. In operation, the deformation amount is added to
the spring 35 in such a state, which generates excessive stress in the spring 35 and
increases the possibility of breakage.
[0035]
20 In Embodiment 2, the insertion depth L1 of the spring 35 can be restricted by
restricting the depth L2 of the female thread 34a as described above. Thus, the
female thread 34a is limited to a depth range that ensures that the spring 35 disposed
therein can avoid excessive stress. Specifically, the depth L2 of the female thread
34a is set to a length that allows for the deformation amount of the spring 35 in
25 operation in a state where the spring 35 is inserted up to a radial inner end of the
female thread 34a. This can reduce a design margin for fatigue resistance of the
spring 35.
[0036]
As described above, Embodiment 2 enables restricting the insertion depth L1
30 of the spring 35 by restricting the depth L2 of the female thread 34a, as well as
12
providing the same advantageous effects as provided by Embodiment 1.
Embodiment 2 can reduce a design margin for fatigue resistance of the spring 35 as
the depth L2 of the female thread 34a is set to a length that allows for the deformation
amount of the spring 35 in operation in a state where the spring 35 is inserted up to a
radial inner end of the 5 female thread 34a.
Reference Signs List
[0037]
1 sealed container 1a center body 1b upper body 1c lower
body 2 electric mechanism 2a stator 2b rotor 3 compression
10 mechanism 4 rotary shaft 4a eccentric portion 5 discharge pipe 21 gas
hole 22 air gap 30A first compression mechanism 30B second compression
mechanism 31 cylinder 32 piston 33 vane 33a rear end 33b distal
end 33c recess 34 through-hole 34a female thread 35 spring 35a
end turn 35b distal end 35c handle portion 36 suction port 37
15 discharge notch 40 upper bearing 41 bearing portion 42 end plate
42a discharge port 43 muffler 44 cylinder chamber 44a suction
chamber 44b compression chamber 50 lower bearing 51 bearing portion
52 end plate 53 muffler 60 intermediate plate 70 accumulator 71
container 72 inlet pipe 73 outlet pipe 74 inner pipe A space B
20 inner space D diameter of end turn J wire diameter of spring K diameter of
female thread
13
We Claim:
[Claim 1]
A rotary compressor comprising:
a compression mechanism section configured to compress refrigerant, wherein
the compression mechanism 5 section includes:
an annular cylinder;
a piston configured to rotate inside a cylinder chamber in the cylinder;
a vane configured to move back and forth in a through-hole penetrating
the cylinder in a radial direction; and
10 a spring configured to push the vane to make a distal end of the vane
contact an outer surface of the piston,
the spring includes, at an end thereof opposite from the vane, an end turn
serving as a male thread, and the spring is fixed to the through-hole by the end turn
being screwed into a female thread on an inner surface of the through-hole, and
15 the spring includes a handle portion formed by bending an end of the end turn
inwardly in an inner diameter direction of the spring.
[Claim 2]
The rotary compressor of claim 1, wherein
a depth in the radial direction of the female thread has a length that allows for a
20 deformation amount of the spring in operation in a state where the spring is inserted
up to an inner end in the radial direction of the female thread.