1
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
SCROLL 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 5 scroll compressor.
Background Art
[0002]
In a scroll compressor, an orbiting scroll is made to orbit relative to a stationary
scroll provided in a hermetic container, such that the sizes of a plurality of
10 compression chambers defined between the stationary scroll and the orbiting scroll
are gradually reduced from an outer peripheral side of the chambers toward an inner
peripheral side of the chambers, thereby also performing compression.
[0003]
Such a scroll compressor includes a compression mechanism that includes a
15 compliant frame and a guide frame, in addition to the stationary scroll and the orbiting
scroll described above. The compliant frame supports the orbiting scroll and a main
shaft in an axial direction of the scroll compressor. The main shaft is provided to
drive the orbiting scroll. The guide frame is fixed to the hermetic container, and
supports the compliant frame in a radial direction. Because of movement of the
20 compliant frame relative to the guide frame in the axial direction, the guide frame is
moved, and as a result the orbiting scroll can be moved in the axial direction.
[0004]
In such a manner, in the scroll compressor employing the compliant frame, the
pressure in a boss area space defined provided between the orbiting scroll and the
25 compliant frame is lower than that in the hermetic container. Thus, in a well-known
compressor, a communication hole that causes the boss area space and a
compression chamber to communicate with each other is provided in a base plate of
an orbiting scroll to enable refrigerating machine oil to be supplied to a compression
mechanism because of a pressure difference between the boss area space and the
30 hermetic container (see, for example, Patent Literature 1).
3
[0005]
In a vertical scroll compressor in which a discharge pressure in a hermetic
container is high and a compression mechanism is provided above an electric motor
that drives the compression mechanism, a discharge pressure Pd in an oil reservoir is
high, the oil reservoir being provided in a bottom portion of the hermetic 5 container to
store the refrigerating machine oil. In this case, since refrigerating machine oil
whose discharge pressure Pd is high is supplied to the compression mechanism
located in an upper region of the hermetic container, a boss area space whose
discharge pressure is, for example, a middle pressure Pα lower than the discharge
10 pressure Pd is provided at part of a main shaft that is close to the compression
mechanism. The middle pressure Pα is adjusted by a pressure regulating valve and
a spring provided at the compliant frame. Thus, in design, the middle pressure Pα is
set as the sum of a suction pressure Ps and a pressure regulating spring pressure α,
(Pα = Ps + α).
15 [0006]
Because of a differential pressure ΔP between the discharge pressure Pd in the
oil reservoir and the middle pressure Pα in the boss area space (ΔP = Pd - Pα), the
refrigerating machine oil in the oil reservoir rises in the main shaft and is supplied to
the boss area space at the middle pressure Pα. This oil feed method is referred to
20 as a differential pressure oil feed method.
[0007]
However, in the differential pressure oil feed method, under a condition that the
differential pressure between the discharge pressure Pd and the suction pressure Ps
is, for example, lower than the pressure regulating spring pressure α (Pd - Ps < α), a
25 force that lifts the compliant frame against the pressure regulating spring pressure α
toward the stationary scroll is insufficient. As a result, oil feed because of the
differential pressure cannot be performed.
[0008]
In the differential pressure feed method, in order to enable oil feed because of
30 the differential pressure to be performed under the above condition (Pd - Ps < α), a
4
pressure condition (Pd - Ps ≥ α) under which differential pressure oil feed can be
performed can be set for the boss area space at the middle pressure Pα.
[0009]
Therefore, in the scroll compressor disclosed in Patent Literature 1, an orbital
base plate, the base plate of the orbiting scroll, has the communication 5 hole through
which the boss area space and the compression chamber intermittently communicate
with each other is provided in an orbital base plate that is a base plate of the orbiting
scroll. The scroll compressor has a mechanism that opens the communication hole
between the compression chamber and the boss area space to cause the
10 compression chamber that is being in a compression process and the boss area
space to communicate with each other, at a timing at which the following pressure
condition is satisfied: an intermediate pressure Pm is higher than or equal to the
suction pressure Ps and lower than or equal to the middle pressure Pα (Ps ≤ Pm ≤
Pα).
15 Citation List
Patent Literature
[0010]
Patent Literature 1: Japanese Unexamined Patent Application Publication No.
2011-111969
20 Summary of Invention
Technical Problem
[0011]
However, in the above scroll compressor, there is a possibility that hightemperature
refrigerating machine oil sucked upward from the oil reservoir into the
25 boss area space may flow into the compression chamber through the communication
hole at the timing at which the communication hole is opened. If this happens, the
temperature of the high-temperature refrigerating machine oil that flows into the
compression chamber is higher than that of refrigerant that is sucked into or present
in the compression chamber and heat is thus transferred from the refrigerating
30 machine oil to the refrigerant. As a result, the temperature of the refrigerant rises,
5
and the sucked refrigerant is superheated. Thus, the refrigeration capacity is
deteriorated. Therefore, the scroll compressor compresses a large amount of
refrigerating machine oil, which is an incompressible fluid, and a compression work of
the scroll compressor is increase. Accordingly, there is a possibility that the
performance of the scroll compressor 5 will be reduced.
[0012]
The present disclosure is applied to solve the above problem, and relates to a
scroll compressor that prevents deterioration of the refrigeration capacity and
improves the refrigeration capacity.
10 Solution to Problem
[0013]
A scroll compressor according to an embodiment of the present disclosure is
provided with a stationary scroll and an orbiting scroll. The stationary scroll includes
a scroll lap protruding and spirally formed on a stationary base plate, and the orbiting
15 scroll includes a scroll lap protruding and spirally formed on an orbital base plate.
The stationary scroll and the orbiting scroll are provided such that the scroll lap of the
stationary scroll and the scroll lap of the orbiting scroll are engaged with each other,
and the stationary scroll and the orbiting scroll defines a compression chamber. The
scroll compressor includes: a guide frame that supports in a radial direction a main
20 shaft provided to drive the orbiting scroll, and that is fastened and connected to the
stationary scroll; and a compliant frame that is floated upon reception of a middle
pressure in the compression chamber as a back pressure to press the orbiting scroll
against the stationary scroll. The orbital base plate has a communication hole
through which the compression chamber communicates with a boss area space
25 defined by the compliant frame and the orbiting scroll at a timing at which an
intermediate pressure becomes higher than a suction pressure and lower than the
middle pressure. The communication hole has a flow-amount reducing portion to
reduce a flow amount of refrigerating machine oil that flows between the boss area
space and the compression chamber.
30 Advantageous Effects of Invention
6
[0014]
In the scroll compressor of the embodiment of the present disclosure, the
communication hole that is provided in the orbital base plate and causes the boss
area space and the compression chamber intermittently to communicate with each
other has the flow-amount reducing portion to reduce the 5 flow amount of the
refrigerating machine oil that flows between the boss area space and the
compression chamber. It is therefore possible to reduce the amount of refrigerating
machine oil that flows into the compression chamber, reduces a decrease in the
amount of refrigerant that can be sucked, and thus prevents deterioration of a
10 refrigeration capacity, thus improving the capacity.
Brief Description of Drawings
[0015]
[Fig. 1] Fig. 1 is a vertical sectional view illustrating a scroll compressor
according to Embodiment 1 of the present disclosure.
15 [Fig. 2] Fig. 2 is a vertical sectional view illustrating an orbiting scroll in the
scroll compressor as illustrated in Fig. 1.
[Fig. 3] Fig. 3 is a plan view illustrating a surface of the orbiting scroll that is
opposite to a scroll lap in the scroll compressor as illustrated in Fig. 1.
[Fig. 4] Fig. 4 is a plan view illustrating a surface of the orbiting scroll where the
20 scroll lap in the scroll compressor as illustrated in Fig. 1 is located.
[Fig. 5] Fig. 5 is a vertical sectional view illustrating a compliant frame in the
scroll compressor as illustrated in Fig. 1.
[Fig. 6] Fig. 6 is a vertical longitudinal cross-sectional view illustrating a guide
frame in the scroll compressor of Fig. 1.
25 [Fig. 7] Fig. 7 indicates a trail laid by a communication hole in accordance with
an orbital motion of the orbiting scroll in the scroll compressor as illustrated in Fig. 1.
[Fig. 8] Fig. 8 indicates a relative position of the orbiting scroll to a stationary
scroll and a correlation between the scrolls and the communication hole when a
rotation angle of a main shaft is 0° in the scroll compressor as illustrated in Fig. 1 on
30 the assumption that the rotation angle of the main shaft is 0° when suction of
7
refrigerant is completed.
[Fig. 9] Fig. 9 indicates the relative position of the orbiting scroll to the
stationary scroll and the correlation between the scrolls and the communication hole
when the rotation angle of the main shaft is 90° in the scroll compressor as illustrated
in Fig. 1 on the assumption that the rotation angle of the main shaft 5 is 0° when suction
of the refrigerant is completed.
[Fig. 10] Fig. 10 indicates the relative position of the orbiting scroll to the
stationary scroll and the correlation between the scrolls and the communication hole
when the rotation angle of the main shaft is 180° in the scroll compressor as
10 illustrated Fig. 1 on the assumption that the rotation angle of the main shaft is 0°
when suction of the refrigerant is completed.
[Fig. 11] Fig. 11 indicates the relative position of the orbiting scroll to the
stationary scroll and the correlation between the scrolls and the communication hole
when the rotation angle of the main shaft is 270° in the scroll compressor as
15 illustrated in Fig. 1 on the assumption that the rotation angle of the main shaft is 0°
when suction of the refrigerant is completed.
[Fig. 12] Fig. 12 indicates the relative position of the orbiting scroll to the
stationary scroll and the correlation between the scrolls and the communication hole
when the rotation angle of the main shaft is 360° in the scroll compressor as
20 illustrated in Fig. 1 on the assumption that the rotation angle of the main shaft is 0°
when suction of the refrigerant is completed.
[Fig. 13] Fig. 13 indicates the relative position of the orbiting scroll to the
stationary scroll and the correlation between the scrolls and the communication hole
when the rotation angle of the main shaft is 450° in the scroll compressor as
25 illustrated in Fig. 1 on the assumption that the rotation angle of the main shaft is 0°
when suction of the refrigerant is completed.
[Fig. 14] Fig. 14 indicates the relative position of the orbiting scroll to the
stationary scroll and the correlation between the scrolls and the communication hole
when the rotation angle of the main shaft is 540° in the scroll compressor as
30 illustrated in Fig. 1 on the assumption that the rotation angle of the main shaft is 0°
8
when suction of the refrigerant is completed.
[Fig. 15] Fig. 15 indicates the relative position of the orbiting scroll to the
stationary scroll and the correlation between the scrolls and the communication hole
when the rotation angle of the main shaft is 630° in the scroll compressor as
illustrated in Fig. 1 on condition that the rotation angle of the main 5 shaft is 0° when
suction of the refrigerant is completed.
[Fig. 16] Fig. 16 is a graph for explanation of a relationship between pressure in
a first chamber and a rotation angle of the main shaft in the scroll compressor as
illustrated in Fig. 1.
10 [Fig. 17] Fig. 17 is a vertical sectional view illustrating an orbiting scroll in a
scroll compressor according to Embodiment 2 of the present disclosure.
[Fig. 18] Fig. 18 is a vertical sectional view illustrating an orbiting scroll in a
scroll compressor according to Embodiment 3 of the present disclosure.
Description of Embodiments
15 [0016]
Embodiments of the present disclosure will be described with reference to the
drawings. The configurations of components as described in the full text of the
specification are merely examples and these descriptions of the configurations are
not limiting. In other words, the configurations can be modified as appropriate
20 without deviating from the subject matter or concept that can be read from the
appended claims and the full text of the specification. Scroll compressors modified
in the above manner also fall within the scope of the technical idea of the present
disclosure. In each of the above figures, components that are the same as or
equivalent to those in a previous figure or figures are denoted by the same reference
25 sings. The same is true of the full text of the specification.
[0017]
Embodiment 1

A scroll compressor 1 according to Embodiment 1 of the present disclosure will
30 be described with reference to Fig. 1. Fig. 1 is a vertical sectional view illustrating
9
the scroll compressor 1 according to Embodiment 1 of the present disclosure.
[0018]
As illustrated in Fig. 1, the scroll compressor 1 includes a compression
mechanism 10 and an electric motor 20 that are housed in a hermetic container 2.
The electric motor is provided to drive the compression 5 mechanism 10. The
compression mechanism 10 includes a stationary scroll 11, an orbiting scroll 12, an
Oldham ring 13, a compliant frame 14, and a guide frame 15. The electric motor 20
includes a rotor 21 and a stator 22, and drives the compression mechanism 10 via a
main shaft 30. In Embodiment 1, the electric motor 20 is a brushless direct current
10 (DC) motor, but is not limited to the brushless DC motor. For example, the electric
motor 20 may be a single-phase or three-phase induction motor or other types of
motors.
[0019]
Specifically, the stationary scroll 11 includes a scroll lap 11b that is spirally
15 formed on a stationary base plate 11a. In a central part of the stationary scroll 11, a
gas outlet 11c is formed to allow gas corresponding to a compressed heat medium to
be discharged. Furthermore, a suction pipe 16 is press-fitted into the stationary
scroll 11 in such a manner as to extend through the hermetic container 2 and
communicate with a suction pressure space 11e in a direction orthogonal to the scroll
20 lap 11b. An outer peripheral part of the stationary scroll 11 is fastened to the guide
frame 15 by bolts (not illustrated).
[0020]
The orbiting scroll 12 includes a lap as well as the stationary scroll 11. To be
more specific, the orbiting scroll 12 includes a scroll lap 12b that is spirally formed on
25 an orbital base plate 12a. The stationary scroll 11 and the orbiting scroll 12 are
disposed such that the scroll lap 11b and the scroll lap 12b are engaged with each
other, thereby forming a compression chamber 3.
[0021]
The orbiting scroll 12 also includes an orbital bearing 12c and is supported in
30 such a way as to be rotatable around an orbital shaft portion 32 that is an upper end
10
of the main shaft 30 which will be described later. The Oldham ring 13 is engaged
with the orbiting scroll 12 such that the Oldham ring 13 can be slid forward and
backward. The orbiting scroll 12 can orbit eccentrically relative to the stationary
scroll 11 without rotating on the axis of the orbiting scroll 12.
5 [0022]
A space 17 is provided under the guide frame 15, and a discharge pipe 18 is
connected with the space 17. The discharge pipe 18 communicates with the outside
of the scroll compressor 1. In an upper region in the hermetic container 2, a
discharge gas space 4 is provided. A gas to be compressed that is sucked into the
10 compression chamber 3 from the outside is compressed and is discharged as a hightemperature
and high-pressure heat medium into the discharge gas space 4.
[0023]
The Oldham ring 13 prevents the orbiting scroll 12 from rotating on the axis of
the orbiting scroll 12 relative to the stationary scroll 11, and includes a pair of
15 stationary-scroll claws 13a provided adjacent to the stationary scroll 11 and a pair of
orbiting-scroll claws 13b provided adjacent to the orbiting scroll 12. The stationaryscroll
claws 13a are fitted in an Oldham guide groove 11d formed in an outer
peripheral part of the stationary scroll 11 in such a way as to be slidable forward and
backward. The orbiting-scroll claws 13b are fitted in an Oldham guide groove 12d
20 (see Fig. 3 to be referred to later) formed in an outer peripheral part of the orbiting
scroll 12.
[0024]
The orbital shaft portion 32 is provided as an upper portion of the main shaft
30, is rotatably fitted in the orbital bearing 12c of the orbiting scroll 12, and the axis of
25 the orbital shaft portion 32 is displaced form that of a main shaft portion 31 by a given
dimension. The main shaft 30 includes a main shaft balancer 33 that is shrink-fitted
into lower part of the orbital shaft portion 32. On the main shaft portion 31, which is
located below the part of the orbital shaft portion 32 to which the main shaft balancer
33 is fitted, a main bearing 14a of the compliant frame 14 is rotatably fitted.
30 [0025]
11
A sub shaft portion 34 is formed below the main shaft portion 31 and is
rotatably fitted in a sub bearing 5a of a sub-frame 5 that supports the sub shaft portion
34. The stator 22 of the electric motor 20 is fixed between the sub shaft portion 34
and the main shaft portion 31 by shrink fitting or other methods. The stator 22 is
rotated in accordance with rotation of the rotor 21, thereby driving 5 and rotating the
compression mechanism 10. It should be noted that an upper balancer 6a is fixed to
an upper end of the stator 22, and a lower balancer 6b is fixed to a lower end of the
stator 22 such that the lower balancer 6b is offset from the upper balancer 6a by a
phase difference of 180°.
10 [0026]
Furthermore, an oil pipe 35 is press-fitted into a lower end of the main shaft 30
and serves as an oil supply mechanism. In a bottom portion of the hermetic
container 2 where the oil pipe 35 is located, an oil reservoir 7 is provided to store
refrigerating machine oil 7a. The oil pipe 35 is provided to suck upwards the
15 refrigerating machine oil 7a stored in the oil reservoir 7 and supply the refrigerating
machine oil 7a to sliding portions via a shaft hollow hole 36 in the main shaft 30.
[0027]
The orbiting scroll 12 will be described with reference to Figs. 2 to 4. Fig. 2 is
a vertical sectional view illustrating the orbiting scroll 12 in the scroll compressor 1 as
20 illustrated in Fig. 1. Fig. 3 is a plan view illustrating a surface of the orbiting scroll 12
that is opposite to the scroll lap 12b in the scroll compressor 1 of Fig. 1. Fig. 4 is a
plan view illustrating a surface of the orbiting scroll 12 where the scroll lap 12b in the
scroll compressor 1 as illustrated Fig. 1 is located.
[0028]
25 As illustrated in Fig. 2, at a substantially central part of a surface of the orbital
base plate 12a that is opposite to the scroll lap 12b, a boss 12f is formed in the shape
of a hollow cylinder. The boss 12f and the orbital shaft portion 32 of the upper end of
the main shaft 30 are engaged with each other such that the orbital shaft portion 32 is
rotatable.
30 [0029]
12
The surface of the orbital base plate 12a that is opposite to the scroll lap 12b
has a thrust surface 12e that can be slid over a thrust bearing 14b (see Fig. 1) of the
compliant frame 14 while being pressed to be in contact with the thrust bearing 14b.
[0030]
As illustrated in Fig. 3, in the outer peripheral part of the orbital 5 base plate 12a,
a pair of Oldham guide grooves 12d of the orbiting scroll 12 are formed in a
substantially straight line in such a manner to be shifted in phase from the Oldham
guide groove 11d (see Fig. 1) of the stationary scroll 11 (see Fig. 1) by 90°. In the
Oldham guide grooves 12d of the orbiting scroll 12, the orbiting-scroll claws 13b of
10 the Oldham ring 13 are fitted in such a manner as to be slidable forward and
backward. Furthermore, in the orbital base plate 12a, an extraction hole 12g is
formed as a hole through which the compression chamber 3 and the thrust surface
12e communicate with each other. The extraction hole is used in order to extract
refrigerant gas that is being compressed and guide the refrigerant gas to the thrust
15 surface 12e.
[0031]
In Embodiment 1, as illustrated in Fig. 2, in the orbital base plate 12a of the
orbiting scroll 12, a communication hole 12i is also formed as a hole through which
the compression chamber 3 and a boss area space 12h intermittently communicate
20 with each other. The communication hole 12i is provided to allow oil to be fed due to
a differential pressure even under a condition in which a differential pressure ΔP
between the oil reservoir 7 where a discharge pressure Pd is high and the boss area
space 12h whose pressure is middle pressure Pα is lower than the pressure
regulating spring pressure α and thus oil cannot be fed due to the differential
25 pressure.
[0032]
Specifically, the communication hole 12i has a flow-amount reducing portion
12ia configured to reduce the flow amount of the refrigerating machine oil 7a that
flows between the boss area space 12h and the compression chamber 3. In
30 Embodiment 1, the flow-amount reducing portion 12ia has projections and
13
depressions that are projected and depressed in a direction crossing the flow
direction of the refrigerating machine oil 7a. The flow-amount reducing portion 12ia
can be variously shaped, for example, shaped to have a threaded hole having a
screw thread, as long as the flow-amount reducing portion 12ia is formed in such a
manner as to have projections and depressions. Furthermore, 5 an orbital bearing
space 12j is formed between the orbital bearing 12c of the orbiting scroll 12 and the
main bearing 14a of the compliant frame 14.
[0033]
Next, the compliant frame 14 will be described with reference to Fig. 5. Fig. 5
10 is a vertical sectional view illustrating the compliant frame 14 in the scroll compressor
1 as illustrated in Fig. 1. An upper cylindrical surface and a lower cylindrical surface
of the compliant frame 14 that are two upper and lower portions located at the outer
peripheral part of the compliant frame 14 are supported in a radial direction by an
upper cylindrical surface and a lower cylindrical surface located at an inner peripheral
15 part of the guide frame 15 (see Fig. 1).
[0034]
The main bearing 14a is fitted in a substantially central portion of the compliant
frame 14 to support in the radial direction the main shaft 30, which is driven and
rotated by the electric motor 20 (see Fig. 1). The main bearing 14a and the
20 compliant frame 14 are separated components.
[0035]
In the compliant frame 14, a communicating passage 14c is formed to extend
from a surface of the thrust bearing 14b through the compliant frame 14 in the axial
direction. An opening port 14d of the communicating passage 14c that adjoins the
25 thrust bearing 14b is located to face the extraction hole 12g of the orbiting scroll 12.
[0036]
Next, the guide frame 15 will be described with reference to Fig. 6. Fig. 6 is a
vertical sectional view illustrating the guide frame 15 in the scroll compressor 1 as
illustrated in Fig. 1. In Fig. 6, the compliant frame 14 and the hermetic container 2
30 are partly indicated by dash-dot-dash lines.
14
[0037]
An outer peripheral surface of the guide frame 15 is fixed to the hermetic
container 2 by shrink fitting, welding, or other methods. Between the hermetic
container 2 and the guide frame 15, a flow passage 2a is provided for the refrigerant
gas. The flow passage 2a is configured such that high-pressure 5 refrigerant gas
discharged from the gas outlet 11c (see Fig. 1) of the stationary scroll 11 is guided by
a cutout provided in the outer peripheral part of the guide frame 15 to the discharge
pipe 18 (see Fig. 1) provided between the compression mechanism 10 and the
electric motor 20.
10 [0038]
At an inner peripheral surface of the guide frame 15, the upper cylindrical
surface and the lower cylindrical surface and sealing grooves 15b and 15c are
provided. The upper cylindrical surface and the lower cylindrical surface are fitted to
the upper cylindrical surface and the lower cylindrical surface of an outer peripheral
15 surface of the compliant frame 14, respectively. The sealing grooves 15b and 15c
are formed at respective positions, that is, an upper position and a lower position in
an axial direction of the main shaft 30.
[0039]
A sealing material 19a is provided in the sealing groove 15b, and a sealing
20 material 19b is provided in the sealing groove 15c. A frame space 15a defined by
the inner peripheral surface of the guide frame 15 and the outer peripheral surface of
the compliant frame 14 is hermetically sealed with the two sealing materials 19a and
19b. The frame space 15a communicates only with the communicating passage 14c
of the compliant frame 14. In the frame space 15a, the refrigerant gas that is being
25 compressed and is to be feed through the extraction hole 12g is enclosed.
[0040]

Next, an operation of the scroll compressor 1 will be described. It should be
noted that the following description is made by referring to by way of example the
30 case where the scroll compressor 1 employs the compliant frame 14 that is a high15
pressure shell type of compliant frame in which an interior of the hermetic container 2
is a high-pressure side of a refrigeration cycle circuit.
[0041]
When the scroll compressor 1 is in operation, the compression mechanism 10
takes in refrigerant to be sucked (low-pressure refrigerant gas) from 5 a suction side of
the refrigeration cycle circuit through the suction pipe 16. The sucked refrigerant is
filled into the compression chamber 3 defined by the scroll laps 11b and 12b of the
stationary scroll 11 and the orbiting scroll 12.
[0042]
10 The orbiting scroll 12 is driven by the electric motor 20 via the main shaft 30
and orbits eccentrically relative to the stationary scroll 11 in accordance with rotation
of the main shaft 30 to gradually reduce the capacity of the compression chamber 3
and compress the compression gas. The compression mechanism 10 discharges
high-pressure compression gas obtained by the above compression, as a high15
temperature and high-pressure heat medium, from the gas outlet 11c located at a
central portion of the stationary scroll 11 to the discharge gas space 4 in the hermetic
container 2. In such a manner, the discharge gas discharged as the heat medium is
filled into the discharge gas space 4 in the hermetic container 2, passes through the
space 17 below the guide frame 15, and is discharged from the discharge pipe 18 to
20 the outside of the scroll compressor 1.
[0043]
In a compression process, refrigerant gas having an intermediate pressure Pm
that is being compressed is guided from the extraction hole 12g (see Fig. 2) of the
orbiting scroll 12 to the frame space 15a through the communicating passage 14c of
25 the compliant frame 14, and maintains an intermediate-pressure atmosphere in the
frame space 15a. After changing into high-pressure discharge gas, the discharge
gas causes the inside of the hermetic container 2 to be filled with a high-pressure
atmosphere and is discharged from the discharge pipe 18 to the outside of the scroll
compressor 1.
30 [0044]
16
The refrigerating machine oil 7a stored in the oil reservoir 7 is guided to the
orbital bearing space 12j (see Fig. 2) through the shaft hollow hole 36, which passes
through the main shaft 30 in the axial direction, due to a differential pressure ΔP
between the oil reservoir 7 in which a discharge pressure Pd is high and the boss
area space 12h in which a pressure is middle pressure Pα (5 ΔP = Pd - Pα). The
refrigerating machine oil 7a in which a pressure reaches the intermediate pressure
Pm because of a squeeze of the orbital bearing space 12j is filled into the boss area
space 12h, which is a space surrounded by the orbiting scroll 12 and the compliant
frame 14.
10 [0045]
The refrigerant is guided to the suction pressure space 11e, which is a lowpressure
space, via a pressure regulating valve 8 (see Fig. 1) through which the boss
area space 12h and a space in which atmosphere has a low pressure communicate
with each other, and is sucked together with the low-pressure refrigerant gas into the
15 compression chamber 3. By the compression process, the refrigerating machine oil
7a is discharged together with the high-pressure refrigerant gas into the hermetic
container 2 through the gas outlet 11c.
[0046]
In the scroll compressor 1 according to Embodiment 1, the boss area space
20 12h communicates with an outermost one of a plurality of compression chambers 3
through the communication hole 12i when the rotation angle of the main shaft 30 falls
within a predetermined range, as described in detail later.
[0047]
The outermost one of the plurality of the compression chambers 3 that are
25 defined by the scroll lap 11b of the stationary scroll 11 and the scroll lap 12b of the
orbiting scroll 12, which are engaged with each other, is gradually compressed by the
rotation of the main shaft 30 and is moved to a central part of the compression
mechanism 10 while increasing in pressure.
[0048]
30 A trail laid by the communication hole 12i in accordance with the orbital motion
17
of the orbiting scroll 12 in the scroll compressor 1 will be described with reference to
Figs. 7 to 15. Fig. 7 indicates a trail laid by the communication hole 12i in
accordance with the orbital motion of the orbiting scroll 12 in the scroll compressor 1
as illustrated in Fig. 1. Fig. 8 indicates a relative position of the orbiting scroll 12 to
the stationary scroll 11 and a correlation between the scrolls and 5 the communication
hole 12i when the rotation angle of the main shaft 30 is 0° in the scroll compressor 1
as illustrated in Fig. 1 on the assumption that the rotation angle the main shaft is 0°
when suction of the refrigerant is completed. Fig. 9 indicates the relative position of
the orbiting scroll 12 to the stationary scroll 11 and the correlation between the scrolls
10 and the communication hole 12i when the rotation angle of the main shaft 30 is 90° in
the scroll compressor 1 as illustrated in Fig. 1 on the assumption that the rotation
angle of the main shaft is 0° when suction of the refrigerant is completed. Fig. 10
indicates the relative position of the orbiting scroll 12 to the stationary scroll 11 and
the correlation between the scrolls and the communication hole 12i when the rotation
15 angle of the main shaft 30 is 180° in the scroll compressor 1 as illustrated in Fig. 1 on
the assumption that the rotation angle of the main shaft is 0° when suction of the
refrigerant is completed.
[0049]
Fig. 11 indicates the relative position of the orbiting scroll 12 to the stationary
20 scroll 11 and the correlation between the scrolls and the communication hole 12i
when the rotation angle of the main shaft 30 is 270° in the scroll compressor 1 as
illustrated in Fig. 1 on the assumption that the rotation angle of the main shaft is 0°
when suction of the refrigerant is completed. Fig. 12 indicates the relative position of
the orbiting scroll 12 to the stationary scroll 11 and the correlation between the scrolls
25 and the communication hole 12i when the rotation angle of the main shaft 30 is 360°
in the scroll compressor 1 as illustrated in Fig. 1 on the assumption that the rotation
angle of the main shaft is 0° when suction of the refrigerant is completed. Fig. 13
indicates the relative position of the orbiting scroll 12 to the stationary scroll 11 and
the correlation between the scrolls and the communication hole 12i when the rotation
30 angle of the main shaft 30 is 450° in the scroll compressor 1 as illustrated in Fig. 1 on
18
the assumption that the rotation angle of the main shaft is 0° when suction of the
refrigerant is completed. Fig. 14 indicates the relative position of the orbiting scroll
12 to the stationary scroll 11 and the correlation between the scrolls and the
communication hole 12i when the rotation angle of the main shaft 30 is 540° in the
scroll compressor 1 as illustrated in Fig. 1 on the assumption that the 5 rotation angle of
the main shaft is 0° when suction of the refrigerant is completed. Fig. 15 indicates
the relative position of the orbiting scroll 12 to the stationary scroll 11 and the
correlation between the scrolls and the communication hole 12i when the rotation
angle of the main shaft 30 is 630° in the scroll compressor 1 as illustrated in Fig. 1 on
10 the assumption that the rotation angle of the main shaft is 0° when suction of the
refrigerant is completed.
[0050]
Fig. 7 indicates a trail that is laid by the communication hole 12i, which is
formed in the orbital base plate 12a of the orbiting scroll 12, when the communication
15 hole 12i is rotated in accordance with the orbital motion of the orbiting scroll 12. In
the figure, the communication holes 12i not communicating with the boss area space
12h are indicated by circles of thin solid lines, and the communication holes 12i
communicating with the boss area space 12h are indicated by circles of thick solid
lines.
20 [0051]
It is assumed that when the rotation angle of the main shaft 30 is 0°, suction of
the refrigerant is completed and the outermost chamber 3a is formed as a first
hermetically sealed chamber (see Fig. 8), for example. As rotation of the main shaft
30 advances, the hermetically sealed outermost chamber 3a moves closer to the gas
25 outlet 11c in the central part while decreasing in capacity and increasing in pressure.
[0052]
As illustrated in Figs. 9 to 15, the outermost chamber 3a that is the outermost
one of the plurality of the compression chambers 3 defined by the scroll lap 11b of the
stationary scroll 11 and the scroll lap 12b of the orbiting scroll 12 that are engaged
30 with each other is re-formed each time the main shaft 30 is rotated by 360°. That is,
19
the outermost one of the compression chambers 3 that are re-defined by the scroll lap
11b of the stationary scroll 11 and the scroll lap 12b of the orbiting scroll 12 that are
engaged with each other, each time the main shaft 30 is rotated by 360°, is the
outermost chamber 3a.
5 [0053]
It should be noted that in this example, the outermost one of the plurality of
compression chambers 3 that are successively defined by the scroll lap 11b of the
stationary scroll 11 and the scroll lap 12b of the orbiting scroll 12, which are engaged
with each other, will be referred to as an outermost chamber 3a.
10 [0054]
Re-referring to Fig. 7, the communication hole 12i communicates with the boss
area space 12h when an intermediate pressure Pm of the outermost chamber 3a
hermetically sealed satisfies a pressure condition in which the intermediate pressure
Pm is higher than a suction pressure Ps and lower than a middle pressure Pα (Ps <
15 Pm < Pα). In other words, the communication hole 12i is closed by the surface of
the thrust bearing 14b of the compliant frame 14 when the intermediate pressure PM
does not satisfy the pressure condition.
[0055]
It is indispensable that with respect to the communication hole 12i, the opening
20 port 14d of the compliant frame 14 satisfies the following conditions.
Firstly, the opening port 14d communicates with the boss area space 12h when
the intermediate pressure Pm of the hermetically sealed outermost chamber 3a
satisfies the pressure condition in which the intermediate pressure Pm is higher than
the suction pressure Ps and lower than the middle pressure Pα (Ps < Pm < Pα).
25 Secondly, the opening port 14d does not communicate with the boss area
space 12h when the intermediate pressure Pm of the hermetically sealed outermost
chamber 3a does not satisfy the above pressure condition (Ps < Pm < Pα). In other
words, the communication hole 12i is closed by the surface of the thrust bearing 14b
of the compliant frame 14.
30 [0056]
20
It is indispensable that an opening port of the communication hole 12i that is
located opposite to the opening port 14d and adjacent to the scroll lap 12b
communicates with the outermost chamber 3a of the compression chambers 3 at
least when the opening port 14d communicates with the boss area space 12h.
When the opening port of the communication hole 12i that is 5 located opposite
to the opening port 14d and adjacent to the scroll lap 12b does not communicate with
the boss area space 12h, the opening port of the communication hole 12i that is
located opposite to the opening port 14d and adjacent to the scroll lap 12b may or
may not communicate with the outermost chamber 3a of the compression chambers
10 3.
[0057]
A relationship between the pressure in the outermost chamber 3a and the
rotation angle of the main shaft 30 in the scroll compressor 1 will be described with
reference to Fig. 16. Fig. 16 is a graph for explanation of the relationship between
15 the pressure in the outermost chamber 3a and the rotation angle of the main shaft 30
in the scroll compressor 1 as illustrated in Fig. 1. Fig. 16 indicates a change in the
pressure in the outermost chamber 3a in a range of the rotation angle of the main
shaft 30 from 0°, at which suction of refrigerant to be sucked is completed and the
outermost chamber 3a is formed, to 630°. In Fig, 16, the vertical axis represents the
20 pressure in the outermost chamber 3a, and the horizontal axis represents the rotation
angle of the main shaft 30.
[0058]
When the rotation angle of the main shaft 30 is 0°, suction of the refrigerant to
be sucked is completed and the outermost chamber 3a is formed, and the pressure in
25 the outermost chamber 3a is thus equal to the suction pressure Ps. Then, during the
rotation of the main shaft 30, the outermost chamber 3a moves inwardly while
decreasing in capacity, and the pressure in the outermost chamber 3a gradually rises.
In a period t1 in which the intermediate pressure Pm of the hermetically sealed
outermost chamber 3a satisfies the above pressure condition Ps < Pm < Pα, the boss
30 area space 12h and the outermost chamber 3a communicate with each other.
21
[0059]
In the period t1, the intermediate pressure Pm of the outermost chamber 3a is
lower than the middle pressure Pα of the boss area space 12h. Thus, the refrigerant
and the refrigerating machine oil 7a in the boss area space 12h are drawn into the
outermost chamber 3a. Therefore, the pressure in the outermost 5 chamber 3a is not
released from the outermost chamber 3a into the boss area space 12h even when the
boss area space 12h and the outermost chamber 3a communicate with each other.
[0060]
In this case, after the intermediate pressure Pm of the outermost chamber 3a
10 increases to a level higher than the suction pressure Ps, that is, at and after the
rotation angle of 0° of the main shaft 30 at which the refrigerant has already been
sucked, the boss area space 12h and the outermost chamber 3a communicate with
each other. It is therefore possible to prevent the amount of refrigerant that can be
sucked from being reduced by the refrigerating machine oil 7a that flows into the
15 outermost chamber 3a through the communication hole 12i, and thus prevent a
refrigeration capacity from being reduced.
[0061]
Furthermore, it is also possible to prevent the temperature of refrigerant that is
sucked from being raised by high-temperature refrigerating machine oil 7a, that is,
20 prevents the refrigerant that is sucked from being superheated, and thus prevents a
refrigeration capacity from being reduced. When the intermediate pressure Pm is
higher than the suction pressure Ps, the boss area space 12h and the outermost
chamber 3a communicate with each other. It is therefore possible to reduce the
amount of the refrigerating machine oil 7a that flows into the outermost chamber 3a,
25 and to reduce a compression work that is done to compress the refrigerating machine
oil 7a.
[0062]
As for the intermediate pressure Pm of the hermetically sealed outermost
chamber 3a, from the period t1 onward, the boss area space 12h and the outermost
30 chamber 3a do not communicate with each other, and the pressure in the outermost
22
chamber 3a continuously rises. It should be noted that the period t1 is a range in
which the intermediate pressure satisfies the pressure condition Ps < Pm < Pα. As
illustrated in Figs. 8 to 15, according to specifications of the scroll lap 11b of the
stationary scroll 11 and the scroll lap 12b of the orbiting scroll 12, when the rotation
angle of the main shaft 30 falls within the range of 450° to 540°, 5 the outermost
chamber 3a communicates with the gas outlet 11c, and the pressure in the outermost
chamber 3a reaches the discharge pressure Pd.
[0063]
Where the rotation angle of the main shaft 30 at the time when suction of the
10 refrigerant is completed and the hermetically sealed outermost chamber 3a is formed
is 0°, the communication hole 12i allows the outermost chamber 3a and the boss area
space 12h to communicate with each other during the period t1 in which the rotation
angle of the main shaft 30 falls within the range of approximately 10 to 60°. During
this period t1, the middle pressure Pα, which is the pressure in the boss area space
15 12h, is higher than the pressure in the outermost chamber 3a, and the refrigerant in
the outermost chamber 3a does not flow into the boss area space 12h and does not
affect the performance of the scroll compressor 1.
[0064]

20 As described above, the scroll compressor 1 according to Embodiment 1
obtains the following advantages.
In the scroll compressor 1, under the condition (Pd - Ps = ΔP < α) that oil feed
due to a normal differential pressure cannot be performed, the middle pressure Pα is
set to a pressure lower than the sum of the pressure regulating spring pressure α and
25 the suction pressure Ps at which oil can be fed due to a differential pressure. Thus,
in the scroll compressor 1, the orbital base plate 12a has the communication hole 12i
through which the boss area space 12h and the compression chamber 3 intermittently
communicate with each other. The communication hole 12i causes the compression
chamber 3 that is being subjected to compression to communicate with the boss area
30 space 12h to release the intermediate pressure Pm higher than the suction pressure
23
Ps and lower than the middle pressure Pα (Ps < Pm < Pα) to the boss area space
12h, whereby oil can be fed due to a differential pressure.
[0065]
In such a manner, the communication hole 12i causes the boss area space and
the compression chamber to communicate at a timing at which 5 the intermediate
pressure falls within such a range as to satisfy the pressure condition Ps < Pm < Pα.
As a result, the compression chamber 3 and the boss area space 12h communicate
through the communication hole 12i after the scroll compressor 1 sucks the
refrigerant. It is therefore possible to prevent reduction of the amount of refrigerant
10 that is sucked, and thus prevent deterioration of the performance of the scroll
compressor 1.
[0066]
Moreover, in the scroll compressor 1 of Embodiment 1, the communication hole
12i has the flow-amount reducing portion 12ia configured to reduce the flow amount
15 of the refrigerating machine oil 7a that flows between the boss area space 12h and
the compression chamber 3. To be more specific, the flow-amount reducing portion
12ia in Embodiment 1 is shaped in such a manner as to have projections and
depressions that face in a direction crossing the flow direction of the refrigerating
machine oil 7a. Because of this configuration, it is possible to increase the
20 resistance to the flow of the refrigerating machine oil 7a in the communication hole
12i and thus reduce the flow amount of the refrigerating machine oil 7a. It is
therefore possible to prevent refrigerant that is sucked from being superheated by
high-temperature refrigerating machine oil 7a, reduce a compression work that is
compression of the refrigerating machine oil 7a, which is an incompressible fluid, and
25 improve the performance during the normal operation.
[0067]
Embodiment 2
A scroll compressor 1 according to Embodiment 2 of the present disclosure will
be described with reference to FIG. 17. Fig. 17 is a vertical sectional view illustrating
30 an orbiting scroll 12 in the scroll compressor 1 according to Embodiment 2 of the
24
present disclosure. Descriptions of components that are the same as or similar to
those in Embodiment 1 as described above will be omitted.
[0068]
As illustrated in Fig. 17, in the scroll compressor 1 of Embodiment 2, a
communication hole 12k through which a boss area space 12h 5 and a compression
chamber 3 intermittently communicate with each other has a flow-amount reducing
portion 12ka configured to reduce the flow amount of refrigerating machine oil 7a that
flows between the boss area space 12h and the compression chamber 3. In
Embodiment 2, the flow-amount reducing portion 12ka is tapered such that the cross10
sectional area of a flow passage in the communication hole d decreases in a direction
from the boss area space 12h toward the compression chamber 3. It is therefore
possible to reduce the amount of the refrigerating machine oil 7a that flows into the
compression chamber 3 through the communication hole 12k.
[0069]
15
As described above, in the scroll compressor 1 of Embodiment 2, the
communication hole 12k, through which the boss area space 12h and the
compression chamber 3 intermittently communicate with each other, has the flowamount
reducing portion 12ka configured to reduce the flow amount of the
20 refrigerating machine oil 7a that flows between the boss area space 12h and the
compression chamber 3. The flow-amount reducing portion 12ka is tapered such
that the cross-sectional area of the flow passage in the communication hole
decreases in the direction from the boss area space 12h toward the compression
chamber 3. Thus, it is possible to increase the resistance to the flow of the
25 refrigerating machine oil 7a in the communication hole 12k and reduce the amount of
the refrigerating machine oil 7a that flows into the compression chamber 3 through
the communication hole 12k. That is, the scroll compressor 1 of Embodiment 2
prevents refrigerant that is sucked from being superheated by high-temperature
refrigerating machine oil 7a and reduce a compression work that is compression of
30 the refrigerating machine oil 7a, which is an incompressible fluid. It is therefore
25
possible to improve the performance during the normal operation.
[0070]
Embodiment 3
A scroll compressor 1 according to Embodiment 3 of the present disclosure will
be described with reference to Fig. 18. Fig. 18 is a vertical sectional 5 view illustrating
an orbiting scroll 12 in the scroll compressor 1 according to Embodiment 3 of the
present disclosure. Descriptions of components that are the same as or similar to
those in Embodiment 1 as described above will be omitted.
[0071]
10 As illustrated in Fig. 18, in the scroll compressor 1 of Embodiment 3, a
communication hole 12m through which a boss area space 12h and a compression
chamber 3 intermittently communicate with each other has a flow-amount reducing
portion 12ma configured to reduce the flow amount of refrigerating machine oil 7 that
flows a between the boss area space 12h and the compression chamber 3. In
15 Embodiment 3, the flow-amount reducing portion 12ma is formed to have a step that
protrudes in a direction crossing the flow direction of the refrigerating machine oil 7a.
Because of this configuration, it is possible to reduce the amount of the refrigerating
machine oil 7a that flows into the compression chamber 3 through the communication
hole 12m. It should be noted that the flow-amount reducing portion 12ma may be
20 formed to have a single step or a plurality of steps as long as the step or steps
protrude in the direction crossing the flow direction of the refrigerating machine oil 7a.
[0072]

As described above, in the scroll compressor 1 of Embodiment 3, the
25 communication hole 12m, through which the boss area space 12h and the
compression chamber 3 intermittently communicate with each other, has the flowamount
reducing portion 12ma configured to reduce the flow amount of the
refrigerating machine oil 7a that flows between the boss area space 12h and the
compression chamber 3. The flow-amount reducing portion 12ma is formed in the
30 shape of a step that protrudes in the direction crossing the flow direction of the
26
refrigerating machine oil 7a. Because of this configuration, it is possible to increase
the resistance to the flow of the refrigerating machine oil 7a in the communication
hole 12m and reduce the amount of the refrigerating machine oil 7a that flows into the
compression chamber 3 through the communication hole 12m. That is, in the scroll
compressor 1 of Embodiment 3, it is possible to prevent refrigerant 5 that is sucked
from being superheated by the high-temperature refrigerating machine oil 7a and
reduce a compression work that is compression of the refrigerating machine oil 7a,
which is an incompressible fluid. Thus, it is possible to improve the performance
during the normal operation.
10 Reference Signs List
[0073]
1 scroll compressor 2 hermetic container 2a flow passage 3
compression chamber 3a first chamber (outermost chamber) 4 discharge
gas space 5 sub frame 5a sub bearing 6a upper balancer 6b lower
15 balancer 7 oil reservoir 7a refrigerating machine oil 8 pressure regulating
valve 10 compression mechanism 11 stationary scroll 11a stationary
base plate 11b scroll lap 11c gas outlet 11d Oldham guide groove 11e
suction pressure space 12 orbiting scroll 12a orbital base plate 12b
scroll lap 12c orbital bearing 12d Oldham guide groove 12e thrust
20 surface 12f boss 12g extraction hole 12h boss area space 12i
communication hole 12ia flow-amount reducing portion 12j orbital bearing
space 12k communication hole 12ka flow-amount reducing portion 12m
communication hole 12ma flow-amount reducing portion 13 Oldham ring
13a stationary-scroll hook 13b orbiting-scroll hook 14 compliant frame
25 14a main bearing 14b thrust bearing 14c communicating passage 14d
opening port 15 guide frame 15a frame space 15b sealing groove 15c
sealing groove 16 suction pipe 17 space 18 discharge pipe 19a
sealing material 19b sealing material 20 electric motor 21 rotor 22
stator 30 main shaft 31 main shaft portion 32 orbital shaft portion 33
30 main shaft balancer 34 sub shaft portion 35 oil pipe 36 shaft hollow hole
27
t1 period Pd discharge pressure Pm intermediate pressure Ps suction
pressure Pα middle pressure ΔP differential pressure α pressure
regulating spring pressure
28
We Claim:
[Claim 1]
A scroll compressor that is provided with a stationary scroll and an orbiting
scroll, the stationary scroll including a scroll lap protruding and spirally 5 formed on a
stationary base plate, the orbiting scroll including a scroll lap protruding and spirally
formed on an orbital base plate, the stationary scroll and the orbiting scroll being
provided such that the scroll lap of the stationary scroll and the scroll lap of the
orbiting scroll are engaged with each other, the stationary scroll and the orbiting scroll
10 defining a compression chamber, the scroll compressor comprising:
a guide frame that supports in a radial direction a main shaft provided to drive
the orbiting scroll, and that is fastened and connected to the stationary scroll; and
a compliant frame that is floated upon reception of a middle pressure in the
compression chamber as a back pressure to press the orbiting scroll against the
15 stationary scroll,
wherein the orbital base plate has a communication hole through which the
compression chamber communicates with a boss area space defined by the
compliant frame and the orbiting scroll at a timing at which an intermediate pressure
becomes higher than a suction pressure and lower than the middle pressure, and
20 wherein the communication hole has a flow-amount reducing portion
configured to reduce a flow amount of refrigerating machine oil that flows between the
boss area space and the compression chamber.
[Claim 2]
The scroll compressor of claim 1, wherein the flow-amount reducing portion of
25 the communication hole is shaped to have projections and depressions that face in a
direction crossing a flow direction of the refrigerating machine oil.
[Claim 3]
The scroll compressor of claim 1, wherein the flow-amount reducing portion of
the communication hole is tapered such that a cross-sectional area of a flow passage
30 in the communication hole decreases in a direction from the boss area space toward
29
the compression chamber.
[Claim 4]
The scroll compressor of claim 1, wherein the flow-amount reducing portion of
the communication hole is formed in the shape of a step that protrudes in a direction
crossing a flow direction of the refrigerating 5 machine oil.