JP2024061303A - Electric Compressor - Google Patents

Abstract

[Problem] To provide an electric compressor capable of suppressing liquid compression in a compression section while suppressing the axial size of a rotating shaft. [Solution] The compressor ECP includes a housing 10, a compression section 30 that compresses a refrigerant, and an electric motor 50 that drives the compression section 30. The housing 10 includes an inner housing 16 to which a stator 54 of the electric motor 50 is fixed, a motor housing 12 that contains the inner housing 16 and has a refrigerant suction port 127 formed therein, and a discharge housing 14 fixed to the motor housing 12. The motor housing 12 and the inner housing 16 are separated at least in part of the overlapping portion in the radial direction Dr of the rotating shaft 20. The compressor ECP is structured such that the refrigerant that flows into the inside of the motor housing 12 from the suction port 127 flows through a clearance space 164 formed between the inner housing 16 and the motor housing 12, and is then sucked into the compression section 30. [Selected Figure] Fig. 6

Description

This disclosure relates to an electric compressor.

Conventionally, there is known a device that integrates a compressor and a gas-liquid separation means to save space (see, for example, Patent Document 1). Patent Document 1 discloses a device that suppresses liquid compression in the compressor by arranging the compressor body and electric motor in the lower space inside the sealed case and providing a refrigerant storage chamber that stores liquid refrigerant in the upper space inside the sealed case.

Japanese Patent Application Laid-Open No. 5-256275

However, in Patent Document 1, the compressor body, electric motor, and refrigerant storage chamber are arranged in the axial direction of the rotating shaft, which results in a large axial size. A large axial size in an electric compressor is undesirable because it can lead to reduced mountability, etc. This was discovered after extensive research by the inventors.

The objective of this disclosure is to provide an electric compressor that can suppress liquid compression in the compression section while minimizing the axial size of the rotating shaft.

The invention described in claim 1 is
An electric compressor for use in a vapor compression refrigeration cycle (1),
A housing (10);
A rotating shaft (20) accommodated inside the housing;
a compression section (30) that compresses a refrigerant by rotating a rotary shaft;
an electric motor (50) having a rotor (52) that rotates integrally with the rotary shaft and a stator (54) that is fixed to the housing, and that drives the compression section;
The housing is
an inner housing (16) that accommodates at least a portion of the electric motor and to which the stator is fixed;
an outer housing (12) that accommodates the inner housing and has a refrigerant inlet (127) formed therein;
a discharge housing (14) through which the refrigerant compressed by the compression section is discharged and which is fixed to the external housing;
The external housing and the internal housing are separated at least partially in the radial direction of the rotating shaft, and the refrigerant that flows into the inside of the external housing from the suction port flows through a gap space (164) formed between the internal housing and the external housing and is then sucked into the compression section.

With this structure, the gap formed between the outer housing and the inner housing in the radial direction of the rotating shaft can function as a liquid storage space for storing liquid refrigerant. Therefore, with the electric compressor disclosed herein, it is possible to suppress liquid compression in the compression section while keeping the axial size small.

The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below.

1 is a schematic configuration diagram of a refrigeration cycle including an electric compressor according to a first embodiment. FIG. 1 is a schematic cross-sectional view of an electric compressor according to a first embodiment. FIG. FIG. 3 is a cross-sectional view taken along line III-III of FIG. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. FIG. 3 is an enlarged view of a portion V in FIG. 2 . 3 is an explanatory diagram for explaining an operation of the electric compressor according to the first embodiment. FIG. 5 is an explanatory diagram for explaining a flow of a refrigerant sucked into the inside of the housing from a suction port. FIG. FIG. 3 is an explanatory diagram for explaining how a refrigerant flows in a V portion in FIG. 2 . FIG. 5 is a schematic cross-sectional view of an electric compressor according to a second embodiment. 10 is an explanatory diagram for explaining an operation of the electric compressor according to the second embodiment. FIG.

Embodiments of the present disclosure will be described below with reference to the drawings. In the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments may be given the same reference numerals, and their description may be omitted. In addition, in the embodiments where only some of the components are described, the components described in the preceding embodiments may be applied to the other parts of the components. The following embodiments may be partially combined with each other, as long as the combination does not cause any problems, even if not specifically stated.

First Embodiment
The present embodiment will be described with reference to Figures 1 to 8. In the present embodiment, an example will be described in which an electric compressor according to the present disclosure (hereinafter, referred to as a compressor ECP) is applied to a refrigeration cycle device 1 constituting a vehicle air conditioner.

The refrigeration cycle device 1 constitutes a vapor compression type refrigeration cycle. As shown in FIG. 1, the refrigeration cycle device 1 includes a compressor ECP, a radiator CD, a pressure reducing device EXV, and an evaporator EV. The compressor ECP is a device that compresses and discharges a refrigerant, which is a fluid. The radiator CD is a heat exchanger that exchanges heat between the refrigerant discharged from the compressor ECP and the air blown from the first blower FAN1 to dissipate heat. The pressure reducing device EXV is a device that reduces the pressure of the refrigerant that has passed through the radiator CD and expands it. The evaporator EV is a heat exchanger that exchanges heat between the refrigerant depressurized by the pressure reducing device EXV and the air blown from the second blower FAN2 to evaporate it. The radiator CD may be configured to dissipate heat to a heat medium different from the air blown from the first blower FAN1. The same applies to the evaporator EV.

The refrigeration cycle device 1 uses a fluorocarbon-based refrigerant as the refrigerant. The refrigerant is mixed with a lubricating oil that lubricates each sliding part inside the compressor ECP. A portion of the lubricating oil circulates within the cycle together with the refrigerant. Note that the refrigerant may be a refrigerant other than a fluorocarbon-based refrigerant (e.g., carbon dioxide).

The refrigeration cycle device 1 of this embodiment configures an accumulatorless cycle in which no accumulator is installed in the path from the refrigerant outlet of the evaporator EV to the refrigerant inlet of the compressor ECP. The accumulator is a liquid storage device that separates the refrigerant into gas and liquid and temporarily stores the liquid refrigerant.

The compressor ECP will be described in detail below with reference to FIG. 2. FIG. 2 is an axial cross-sectional view showing a cross-section cut along the axis CL of the rotating shaft 20 of the compressor ECP. Note that the arrows indicating up and down in FIG. 2 indicate the vertical direction Dg when the compressor ECP is mounted on a vehicle. Also, in FIG. 2, the direction along the axis CL of the rotating shaft 20 is the axial direction Dax, and the direction perpendicular to the axis CL of the rotating shaft 20 is the radial direction Dr. These are the same in other drawings as well as FIG. 2.

As shown in FIG. 2, the compressor ECP includes a housing 10, a rotating shaft 20, a compression section 30, and an electric motor 50. The rotating shaft 20, the compression section 30, and the electric motor 50 are housed inside the housing 10. The compressor ECP has a horizontally mounted structure in which the axis CL of the rotating shaft 20 extends in a substantially horizontal direction, and the compression section 30 and the electric motor 50 are aligned in a substantially horizontal direction and installed in the vehicle.

The housing 10 includes a motor housing 12, a discharge housing 14, and an inner housing 16. The motor housing 12, the discharge housing 14, and the inner housing 16 are made of metal materials. The motor housing 12 and the discharge housing 14 are external housings that form the outer shell of the compressor ECP. The motor housing 12 and the discharge housing 14 are made of, for example, aluminum or an aluminum alloy.

The motor housing 12 accommodates the internal housing 16. The motor housing 12 is a cylindrical shape with a bottom that is open on one side in the axial direction Dax of the rotating shaft 20. Specifically, the motor housing 12 has a plate-shaped first bottom wall portion 121 and a first outer peripheral wall portion 122 that extends in a cylindrical shape from the outer peripheral portion of the first bottom wall portion 121. The motor housing 12 is configured as a seamless, integrally molded product with the first bottom wall portion 121 and the first outer peripheral wall portion 122. In this embodiment, the motor housing 12 constitutes the "external housing".

The motor housing 12 has a stepped shape with a step surface 123 formed on the inner portion of the first outer wall portion 122. The step surface 123 intersects with the axial direction Dax. In this embodiment, the step surface 123 extends along the radial direction Dr of the rotating shaft 20.

The step surface 123 is set between a first housing part 124, which has a smaller inner diameter in the inner part of the motor housing 12, and a second housing part 125, which has a larger inner diameter than the first housing part 124. Specifically, a protrusion 126 that protrudes closer to the rotating shaft 20 is provided between the first housing part 124 and the second housing part 125. The facing surface of the protrusion 126 that faces the shaft support member 40 constitutes the step surface 123.

The first housing portion 124 is a portion connected to the first bottom wall portion 121. The inner housing 16 is housed inside the first housing portion 124. The shaft support member 40 and a part of the compression portion 30 are housed inside the second housing portion 125.

Although not shown, the first bottom wall portion 121 of the motor housing 12 is provided with an airtight terminal to which the electrical wiring of the electric motor 50 is connected. The electric motor 50 is electrically connected to an inverter (not shown) via the airtight terminal.

The motor housing 12 is formed with a refrigerant suction port 127. The refrigerant outlet side of the evaporator EV is connected to this suction port 127. Therefore, the space in the housing 10 in which the electric motor 50 is disposed is a low-pressure, low-temperature atmosphere. This allows the electric motor 50 to be cooled, improving the efficiency and reliability of the electric motor 50.

In this embodiment, the suction port 127 is formed in a position on the motor housing 12 that does not face the inner housing 16. Specifically, the suction port 127 is provided above the axis CL of the rotating shaft 20 in the motor housing 12 in the vertical direction Dg. The refrigerant drawn in from the suction port 127 flows through the gap space 164 between the motor housing 12 and the inner housing 16.

As described above, the refrigeration cycle device 1 of this embodiment is configured as an accumulatorless cycle. Therefore, depending on the load condition of the refrigeration cycle device 1, the refrigerant may not completely evaporate in the evaporator EV, and two-phase gas-liquid refrigerant including liquid refrigerant may flow into the gap space 164 through the suction port 127.

The discharge housing 14 forms a space into which the refrigerant compressed in the compression section 30 is discharged. The discharge housing 14 is a cylindrical shape with a bottom that opens on the other side in the axial direction Dax of the rotating shaft 20. Specifically, the discharge housing 14 has a plate-shaped second bottom wall portion 141 and a second outer peripheral wall portion 142 that extends in a cylindrical shape from the outer peripheral portion of the second bottom wall portion 141. The discharge housing 14 is configured as a seamless one-piece molded product in which the second bottom wall portion 141 and the second outer peripheral wall portion 142 are integrally molded.

The discharge housing 14 is fixed to the motor housing 12 by fastening bolts 15 with the opening edge on the other side of the axial direction Dax of the discharge housing 14 butting against the opening edge on one side of the axial direction Dax of the motor housing 12. The motor housing 12 and the discharge housing 14 form a pressure vessel. The atmosphere consisting of low-pressure, low-temperature refrigerant inside the motor housing 12 and the atmosphere consisting of high-pressure, high-temperature refrigerant discharged from the compression section 30 are separated by a sealing member (not shown).

Although not shown, the discharge housing 14 has a refrigerant discharge port. The refrigerant inlet side of the radiator CD is connected to this discharge port. An oil separator that separates the lubricating oil in the refrigerant is installed in the discharge port. Therefore, the lubricating oil in the refrigerant discharged from the compression section 30 is stored inside the discharge housing 14.

The rotating shaft 20 is accommodated inside the housing 10. Specifically, the rotating shaft 20 is disposed inside the motor housing 12 so that the axis CL coincides with the central axis of the first outer peripheral wall portion 122 of the motor housing 12.

The rotating shaft 20 has an eccentric shaft portion 21 at one end in the axial direction Dax, which is eccentric from the axis CL of the rotating shaft 20. The eccentric shaft portion 21 is integral with the main body of the rotating shaft 20. The eccentric shaft portion 21 is supported by an eccentric bearing portion 344 provided on a first boss portion 343 of the orbiting scroll 34, which will be described later.

The rotating shaft 20 has an enlarged diameter section 22 adjacent to the eccentric shaft section 21, the outer diameter of which is enlarged. This enlarged diameter section 22 is provided with a balance weight 23 to suppress eccentric rotation of the rotating shaft 20.

An oil supply passage 24 is formed inside the rotating shaft 20 to supply lubricating oil to the eccentric bearing 344, the first bearing 411 described later, the second bearing 17, etc. The oil supply passage 24 is connected to the inside of the discharge housing 14 via an oil supply path (not shown) formed in the fixed scroll 32 and the orbiting scroll 34. The lubricating oil stored inside the discharge housing 14 is supplied to the eccentric bearing 344, the first bearing 411 described later, the second bearing 17, etc. via the oil supply path and the oil supply passage 24.

The compression section 30 is configured as a scroll-type compression mechanism. The compression section 30 has a fixed scroll 32, an orbiting scroll 34, and a discharge plate 36. The orbiting scroll 34, the fixed scroll 32, and the discharge plate 36 are arranged in this order in the axial direction Dax. The fixed scroll 32, the orbiting scroll 34, and the discharge plate 36 are made of steel material, aluminum alloy, etc.

The fixed scroll 32 has a fixed base portion 321 formed in a disk shape and a spiral-shaped fixed tooth portion 322 that protrudes from the fixed base portion 321 toward the orbiting scroll 34 on the other side in the axial direction Dax.

The orbiting scroll 34 has a disk-shaped orbiting base portion 341 and a spiral orbiting tooth portion 342 that protrudes from the orbiting base portion 341 toward the fixed scroll 32 on one side in the axial direction Dax.

The orbiting scroll 34 has a cylindrical first boss portion 343 on the side of the orbiting base plate portion 341 opposite the orbiting teeth portion 342. An eccentric bearing portion 344 is provided inside the first boss portion 343. The eccentric bearing portion 344 is made of a plain bearing. The eccentric bearing portion 344 may be made of a bearing other than a plain bearing.

An Oldham ring 35 is connected to the orbiting scroll 34. The Oldham ring 35 constitutes a rotation prevention mechanism that prevents the orbiting scroll 34 from rotating on its axis. When the rotating shaft 20 rotates, the orbiting scroll 34 performs an orbital motion (i.e., an orbital motion) around the axis center CL of the rotating shaft 20. Note that the rotation prevention mechanism may be composed of something other than the Oldham ring 35.

Between the fixed scroll 32 and the orbiting scroll 34, the fixed teeth 322 and the orbiting teeth 342 mesh and come into contact at multiple points, forming multiple crescent-shaped working chambers 31. As the orbiting scroll 34 orbits, the working chambers 31 move from the outer periphery to the center while decreasing in volume. For convenience, in FIG. 2 and other figures, only one of the multiple working chambers 31 is labeled with a reference number.

The working chamber 31 is supplied with refrigerant drawn from a refrigerant suction passage 38 formed adjacent to the compression section 30. In this embodiment, the refrigerant suction passage 38 is formed on the outer periphery of the fixed scroll 32 and the orbiting scroll 34. The refrigerant supplied from the refrigerant suction passage 38 to the working chamber 31 is compressed by reducing the volume of the working chamber 31.

A discharge hole 323 is formed in the center of the fixed base plate part 321 to discharge the refrigerant compressed in the working chamber 31. A reed valve (not shown) that serves as a check valve to prevent the refrigerant from flowing back into the working chamber 31, and a stopper 324 that regulates the maximum opening degree of the reed valve are provided on one end face of the fixed base plate part 321 in the axial direction Dax. The reed valve and stopper 324 are fastened and fixed to the fixed base plate part 321 by bolts 325.

The discharge plate 36 is disposed adjacent to the fixed scroll 32. Between the discharge plate 36 and the fixed scroll 32, a muffler chamber 361 is formed to reduce discharge pulsation of the refrigerant discharged from the discharge hole 323. The discharge plate 36 is formed in a cup shape. Although not shown, an outlet port is formed at the bottom of the discharge plate 36 to discharge the refrigerant from the muffler chamber 361. Note that the discharge plate 36 is not an essential component of the compression section 30.

The fixed scroll 32 and the discharge plate 36 have approximately the same outer diameter. The fixed scroll 32 and the discharge plate 36 have approximately the same outer diameter as the inner diameter of the second housing portion 125.

The compression section 30 thus configured is fixed to the step surface 123 of the motor housing 12 via the shaft support member 40 by a mounting bolt (not shown). The step surface 123 of the motor housing 12 constitutes a fixing portion for fixing the compression section 30.

The shaft support member 40 includes a first bearing portion 411 that rotatably supports the rotating shaft 20. The shaft support member 40 is disposed between the compression section 30 and the electric motor 50. Between the shaft support member 40 and the fixed scroll 32, a space is formed to accommodate the orbiting scroll 34, the Oldham ring 35, a part of the rotating shaft 20, etc. The shaft support member 40 is made of steel material, aluminum alloy, etc.

The shaft support member 40 has a cylindrical shape. The outer diameter and inner diameter of the shaft support member 40 are gradually reduced from one side to the other side in the axial direction Dax. Specifically, the shaft support member 40 has a small diameter portion 41 where the inner diameter is the smallest, a large diameter portion 42 where the outer diameter is the largest, and a connecting portion 43 that connects the small diameter portion 41 and the large diameter portion 42. The small diameter portion 41, the large diameter portion 42, and the connecting portion 43 are integrally configured.

The shaft support member 40 has a first bearing portion 411 formed on the inner periphery side of the small diameter portion 41. The first bearing portion 411 is made of a plain bearing. The first bearing portion 411 is made of a cylindrical steel member and a resin layer coated on its inner periphery. The first bearing portion 411 may be made of the same material as the shaft support member 40 and may be integrally formed with the shaft support member 40. The first bearing portion 411 may be made of a bearing other than a plain bearing.

A circular thrust plate 44 is disposed between the shaft support member 40 and the orbiting scroll 34. The thrust plate 44 allows the orbiting scroll 34 to slide relative to the shaft support member 40.

The outer diameter of the large diameter portion 42 of the shaft support member 40 is set to be approximately the same as the dimensions of the fixed scroll 32 and the discharge plate 36. The outer diameter of the large diameter portion 42 of the shaft support member 40 is larger than the inner diameter of the first housing portion 124 of the motor housing 12 and smaller than the inner diameter of the second housing portion 125.

Between the shaft support member 40 and the motor housing 12, a refrigerant introduction passage 45 is provided to guide the refrigerant from the inside of the internal housing 16 to the compression section 30. This refrigerant introduction passage 45 is provided at least below the axis CL of the rotating shaft 20. The refrigerant introduction passage 45 is a passage that connects the inside of the internal housing 16 with the refrigerant suction passage 38. In this embodiment, one refrigerant introduction passage 45 is provided below the axis CL of the rotating shaft 20. Note that multiple refrigerant introduction passages 45 may be formed between the shaft support member 40 and the motor housing 12. Note that the refrigerant introduction passage 45 may be provided, for example, penetrating the shaft support member 40.

The shaft support member 40 configured in this manner is fixed to the motor housing 12 together with the compression section 30 by mounting bolts (not shown).

The electric motor 50 is configured as an inverter-driven DC motor that is driven by power supplied from an inverter (not shown). It is arranged on the other side of the shaft support member 40 in the axial direction Dax. The electric motor 50 drives the compression section 30 and has a rotor 52 that rotates integrally with the rotating shaft 20 and a stator 54 that is fixed to the housing 10. The electric motor 50 is configured as an inner rotor motor in which the rotor 52 is arranged inside the stator 54.

The rotor 52 is a cylindrical member to which the rotating shaft 20 is fixed by press-fitting or the like. A permanent magnet (not shown) is disposed inside the rotor 52. In addition, balance weights 521 and 522 are attached to the side of the rotor 52 to offset the imbalance of the eccentric rotation of the orbiting scroll 34 and the like.

The stator 54 has a stator core 541 made of a metallic magnetic material and a coil 542 wound around the stator core 541. When power is supplied to the stator 54 from an inverter (not shown), the stator 54 generates a rotating magnetic field that rotates the rotor 52. The stator 54 is fixed to the cylindrical portion 161 of the inner housing 16 by shrink fitting or press fitting.

The inner housing 16 is accommodated inside the motor housing 12. The stator 54 is fixed to the inner housing 16. The inner housing 16 is made of the same metal material as the stator 54. When the stator 54 is made of a steel material, the inner housing 16 is made of the same steel material as the stator 54 (e.g., iron).

Here, the operating environment range of the on-vehicle compressor ECP is assumed to be -40 to 100°C, taking into consideration everything from low outside temperatures to heat generated by the main motor and engine. Electromagnetic steel sheets are generally used for the stator core 541. Taking these factors into consideration, it is desirable for the constituent material of the inner housing 16 to have a linear expansion coefficient of 20×10 ^-6 [/°C] or less.

By reducing the difference in linear expansion coefficient between the stator 54 and the internal housing 16, the tightening margin can be set appropriately in the expected temperature range. For example, if a metal material with a large linear expansion coefficient such as aluminum is used as the material for the internal housing 16, the difference in linear expansion coefficient with the stator 54 will be large. Therefore, when a tightening margin that can ensure tension in the high temperature range is set and a low outside air range is assumed, the tightening margin increases. This increases the distortion of the stator core 541 and reduces the efficiency of the electric motor 50. Conversely, if the tightening margin is set so that the effect of distortion is small at low outside air temperatures, there is a risk that the tension will decrease and the fixation of the stator 54 will become unstable at high outside air temperatures.

The internal housing 16 has a generally cup-shaped configuration. The internal housing 16 has a cylindrical tube portion 161 to which the stator 54 is fixed, and a flange portion 162 that protrudes from one end 161a of the tube portion 161 close to the compression portion 30 in a direction away from the rotating shaft 20. The internal housing 16 also includes a support portion 163 that extends from the other end 161b located opposite the one end 161a so as to approach the rotating shaft 20 and support the second bearing portion 17. The tube portion 161, the flange portion 162, and the support portion 163 are configured as an integrally molded product. In this embodiment, the support portion 163 configures the "bottom surface portion" of the internal housing 16. Note that the tube portion 161, the flange portion 162, and the support portion 163 may be partially configured as separate bodies.

The support portion 163 has a bottom portion 163a in an annular shape connected to the other end portion 161b of the tube portion 161, and a cylindrical second boss portion 163b provided in the center portion of the bottom portion 163a. The second boss portion 163b protrudes from the other side to one side in the axial direction Dax so that a part of the second boss portion 163b overlaps with the stator 54 in the radial direction Dr. The second bearing portion 17 is formed on the inner peripheral side of the second boss portion 163b. The second bearing portion 17 is composed of a sliding bearing. The second bearing portion 17 is composed of a cylindrical steel member and a resin layer coated on its inner peripheral surface. The second bearing portion 17 may be composed of the same material as the inner housing 16 and may be integral with the shaft support member 40. The second bearing portion 17 may be composed of a bearing other than a sliding bearing.

The outer diameter of the cylindrical portion 161 of the inner housing 16 is smaller than the inner diameter of the first housing portion 124 of the motor housing 12. The outer diameter of the flange portion 162 of the inner housing 16 is larger than the inner diameter of the first housing portion 124 of the motor housing 12 and smaller than the inner diameter of the second housing portion 125.

The entire flange portion 162 of the internal housing 16 faces the shaft support member 40 in the axial direction Dax. The flange portion 162 is fixed to the shaft support member 40 by a fixing bolt (not shown).

The internal housing 16 is formed with an internal/external communication part 165 that penetrates from the inside to the outside. As a result, the refrigerant sucked from the suction port 127 of the motor housing 12 into the gap space 164 between the motor housing 12 and the internal housing 16 is supplied to the inside of the internal housing 16 via the internal/external communication part 165.

In this embodiment, the internal/external communication portion 165 is provided above the axis CL of the rotating shaft 20 in the vertical direction Dg. Specifically, the internal/external communication portion 165 is provided in each of the tube portion 161 and the bottom portion 163a constituting the bottom surface portion of the inner housing 16. That is, the internal/external communication portion 165 has a tube side communication portion 165a provided in the tube portion 161 and a bottom side communication portion 165b provided in the bottom portion 163a.

The cylinder side communication part 165a is provided in a position close to the shaft support member 40 in a part of the cylinder part 161 above the axis CL of the rotating shaft 20. The gas refrigerant present in the gap space 164 passes through the cylinder side communication part 165a and flows into the inside of the inner housing 16. The refrigerant that passes through the cylinder side communication part 165a flows along the surface of the shaft support member 40 and is then introduced into the refrigerant introduction passage 65.

The bottom-side communication part 165b is provided at a portion of the bottom 163a above the axis CL of the rotating shaft 20. The gas refrigerant present in the gap space 164 passes through the bottom-side communication part 165b and flows inside the inner housing 16. The refrigerant that passes through the bottom-side communication part 165b flows through the gap between the rotor 52 and the stator 54, and is then introduced into the refrigerant introduction passage 65.

On the other hand, the inside of the inner housing 16 and the gap space 164 between the motor housing 12 and the inner housing 16 are partitioned by the tubular portion 161 and the bottom portion 163a so that the inside and outside of the inner housing 16 are not connected to each other below the axis CL in the vertical direction Dg. In other words, the inner housing 16 does not have an inside-outside communication portion 165 below the axis CL in the vertical direction Dg.

Here, in the compressor ECP of this embodiment, the wiring that electrically connects the stator 54 and the airtight terminal is pulled out from the stator 54 to the airtight terminal via the internal/external communication part 165. In this way, by using the internal/external communication part 165 as a route for pulling out the wiring, etc., the structure of the compressor ECP can be simplified and costs can be reduced.

The inner housing 16, shaft support member 40, and compression section 30 are arranged in this order in the axial direction Dax. The inner housing 16 and compression section 30 are fixed to the stepped surface 123 of the motor housing 12 by mounting bolts (not shown) at the portion between the stator 54, which is a heavy part, and the compression section 30.

Specifically, as shown in FIG. 3, the inner housing 16 is fixed to the step surface 123 of the motor housing 12 with the portion other than the flange portion 162 spaced apart from the first housing portion 124.

The inner housing 16 has an axial length Dax that is smaller than the axial length Dax from the step surface 123 to the first bottom wall portion 121 in the motor housing 12. As a result, a gap is formed between the support portion 163 and the motor housing 12 in the inner housing 16.

A separation plate 18 is disposed between the support portion 163 of the inner housing 16 and the first bottom wall portion 121 of the motor housing 12. This separation plate 18 promotes separation of the gas and liquid refrigerant by colliding the refrigerant introduced into the gap space 164 from the suction port 127. The separation plate 18 is disposed below the axis CL of the rotating shaft 20 in the vertical direction Dg so as not to impede the flow of gas refrigerant to the internal/external communication portion 165.

Specifically, the separation plate 18 is made of a punched metal with many holes formed therein that penetrate from the front to the back. The shape of the holes is not particularly limited and may be, for example, a round hole, a slit hole, or the like. Furthermore, a plurality of separation plates 18 may be arranged in a line in the vertical direction Dg. Furthermore, the separation plate 18 may be fixed to either the motor housing 12 or the inner housing 16. However, it is desirable to arrange the separation plate 18 so that it is separated from either the motor housing 12 or the inner housing 16 so that the separation plate 18 does not become a vibration transmission element.

The first outer peripheral wall portion 122 of the motor housing 12 is provided with a protrusion 166 that protrudes toward the rotating shaft 20 and extends in the axial direction Dax of the rotating shaft 20. The protrusion 166 may be integral with the motor housing 12, or may be formed separately and attached to the motor housing 12.

As shown in Figures 3 and 4, the protrusion 166 is provided in a portion of the first outer wall portion 122 that faces the internal housing 16. The protrusion 166 may be provided over the entire portion that faces the internal housing 16 in the axial direction Dax, or may be provided partially.

The protrusion 166 has a protruding height Lh set so as not to come into contact with the internal housing 16. The protrusion 166 is formed at a position that is approximately the same height as the rotating shaft 20 in the vertical direction Dg. The position at which the protrusion 166 is provided is not limited to the position shown in Figures 3 and 4, but it is preferable that the protrusion 166 is provided below the suction port 127 in the vertical direction Dg. In addition, it is preferable that the protrusion 166 is provided at a position equivalent to the separation plate 18 or above the separation plate 18 in the vertical direction Dg.

Furthermore, inside the housing 10, a communication passage 19 is provided that connects the gap space 164 formed between the motor housing 12 and the inner housing 16 to the refrigerant introduction passage 45. The communication passage 19 is a throttle passage with a smaller flow cross-sectional area than the refrigerant introduction passage 45.

Specifically, as shown in FIG. 5, the communication passage 19 includes a first through hole 191 provided in the protrusion 126 provided in the motor housing 12 and a second through hole 192 provided in the flange portion 162 of the inner housing 16.

The first through hole 191 is formed on the base side of the protrusion 126. The second through hole 192 is formed on the tip side of the flange portion 162 so as to overlap with the first through hole 191 in the axial direction Dax.

The size of each of the first through hole 191 and the second through hole 192 is smaller than the cross-sectional area of the refrigerant introduction flow path 45. Specifically, the hole diameter φ1 of the first through hole 191 is larger than the hole diameter φ2 of the second through hole 192 and is smaller than the flow path height FH of the refrigerant introduction flow path 45. The hole diameter φ1 of the first through hole 191 may be equal to or smaller than the hole diameter φ2 of the second through hole 192.

Next, the operation of the compressor ECP will be described with reference to Figures 6 to 8. When power is supplied to the stator 54 of the electric motor 50 from an inverter (not shown), the compressor ECP rotates the rotor 52 and the rotating shaft 20, and the orbiting scroll 34 revolves around the rotating shaft 20. This drives the compression section 30, and the low-temperature, low-pressure refrigerant that has passed through the evaporator EV is sucked into the inside of the housing 10 through the suction port 127.

Specifically, as shown by the arrow FR1 in Figures 6 and 7, the refrigerant flows into the gap space 164 formed between the motor housing 12 and the inner housing 16, and is then introduced into the inside of the inner housing 16 through the inside-outer communication part 165.

The internal/external communication part 165 is formed above the axial center CL of the rotating shaft 20 in the internal housing 16. The gas refrigerant, which has a low specific gravity, is introduced into the inside of the internal housing 16 through the internal/external communication part 165, while the liquid refrigerant, which has a high specific gravity, is stored in the gap space 164 as shown in FIG. 7. In particular, since the separation plate 18 is arranged in the gap space 164, the gas and liquid refrigerant can be appropriately separated.

Here, when the liquid refrigerant stored in the gap space 164 is heated by the heat generated by the compression section 30 and the electric motor 50 doing work, it may become gasified and be introduced into the inside of the inner housing 16 through the internal/external communication section 165.

The refrigerant introduced into the inner housing 16 passes through the gaps between the various components of the electric motor 50 and the refrigerant introduction passage 45 provided between the motor housing 12 and the shaft support member 40. The refrigerant passing through the refrigerant introduction passage 45 flows into the refrigerant suction passage 38 formed on the outer periphery of the fixed scroll 32 as shown by the arrow FR2 in FIG. 6, and is then sucked into the working chamber 31 from the refrigerant suction passage 38. The refrigerant supplied to the working chamber 31 is compressed as the volume of the working chamber 31 decreases. When the pressure in the working chamber 31 reaches the valve opening pressure of the reed valve, the refrigerant compressed in the working chamber 31 is discharged from the discharge hole 323 of the fixed scroll 32 to the muffler chamber 361 as shown by the arrow FR3 in FIG. The refrigerant discharged into the muffler chamber 361 flows into the inside of the discharge housing 14 from the outlet provided in the discharge plate 36, and is then discharged from the discharge port provided in the discharge housing 14 as discharge refrigerant for the compressor ECP. At this time, the lubricating oil contained in the discharged refrigerant is separated by an oil separator provided at the discharge port, and falls under its own weight and accumulates on the lower side of the discharge housing 14. The lubricating oil is then supplied to each sliding part inside the housing 12 via the oil supply passage 24 etc. due to the pressure difference of the refrigerant inside the housing 10. A part of the lubricating oil supplied to the sliding parts flows into the gap space 164. Unlike the refrigerant, the lubricating oil does not vaporize, so it temporarily accumulates in a liquid state on the lower side of the gap space 164, but is led to the refrigerant introduction passage 45 via the communication passage 19 that communicates the gap space 164 and the refrigerant introduction passage 45.

Here, the communication flow path 19 is a throttle flow path with a smaller flow cross-sectional area than the refrigerant introduction flow path 45. Therefore, the gas refrigerant flowing through the inner housing 16 passes through the refrigerant introduction flow path 45, which has a smaller pressure loss than the communication flow path 19, and easily flows to the refrigerant suction flow path 38. At this time, the refrigerant flow from the refrigerant introduction flow path 45 to the refrigerant suction flow path 38 draws the liquid refrigerant containing the lubricating oil stored in the gap space 164 into the refrigerant suction flow path 38, as shown in FIG. 8.

In the compressor ECP of this embodiment described above, the motor housing 12 and the inner housing 16 are separated in parts that overlap in the radial direction Dr of the rotating shaft 20. The refrigerant that flows into the inside of the motor housing 12 from the suction port 127 flows through the gap space 164 formed between the inner housing 16 and the motor housing 12, and is then sucked into the compression section 30.

In this structure, the gap formed between the motor housing 12 and the inner housing 16 in the radial direction Dr of the rotating shaft 20 can function as a liquid storage space for storing liquid refrigerant. Therefore, compared to a structure in which the space accommodating the electric motor 50 and the liquid storage space are arranged in the axial direction Dax, it is possible to suppress liquid compression in the compression section 30 while keeping the size in the axial direction Dax down.

However, if the internal housing 16 and the compression section 30 are fixed to the discharge housing 14 in a cantilever-like manner, the distance between the position that supports the internal housing 16 and the compression section 30 and the position where the vibration occurs becomes large, and the amplitude of the vibration becomes large.

In particular, when the space housing the electric motor 50 and the liquid storage space are arranged in the axial direction Dax, the amplitude of vibration increases. In this case, the amplitude of the piping and other components connected to external equipment of the compressor ECP also increases, which may increase noise levels and damage the connections. In addition, when the space housing the electric motor 50 and the liquid storage space are arranged in the axial direction Dax, the wiring connecting the stator 54 and the airtight terminal must be arranged to avoid the area that forms the liquid storage space, which complicates the structure of the compressor ECP.

In contrast to these, the compressor ECP of this embodiment has a portion located midway between the internal housing 16 and the compression section 30 fixed to the step surface 123 of the motor housing 12. This makes it possible to reduce the distance between the position supporting the internal housing 16 and the compression section 30 and the position where vibration occurs, compared to when the internal housing 16 and the compression section 30 are fixed in a cantilever-like manner. In particular, in the compressor ECP of this embodiment, the liquid storage space is formed outside the radial direction Dr of the electric motor 50. As a result, the vibration of the electric motor 50 and the compression section 30 is reduced and is less likely to be transmitted to the motor housing 12, thereby suppressing noise.

Moreover, the compressor ECP of this embodiment has the following features.
(1) The inner housing 16 is provided with an interior/exterior communication portion 165 that communicates the inside and outside of the inner housing 16. The refrigerant that flows into the inside of the motor housing 12 from the suction port 127 flows through the gap space 164, and is then introduced into the inside of the inner housing 16 via the interior/exterior communication portion 165 and sucked into the compression section 30. With this, liquid refrigerant with a high specific gravity is stored in the gap space 164, while gas refrigerant with a low specific gravity can be caused to flow from the inside of the inner housing 16 toward the compression section 30 via the interior/exterior communication portion 165.

(2) Specifically, the internal housing 16 includes a cylindrical tube portion 161 to which the stator 54 is fixed, and a support portion 163 extending from an end portion 161b of the tube portion 161 located on the opposite side to an end portion 161a closer to the compression portion 30, toward the rotating shaft 20. At least one of the tube portion 161 and the support portion 163 is provided with an inside-outside communication portion 165 that communicates between the inside and outside of the internal housing 16, at a location located above the axis CL of the rotating shaft 20 in the vertical direction Dg.

This allows the liquid refrigerant, which has a high specific gravity, to be stored in the lower part of the gap space 164, while the gas refrigerant, which has a low specific gravity, can flow from the inside of the internal housing 16 toward the compression section 30 via the internal/external communication section 165.

In particular, the internal/external communication portion 165 of this embodiment has a cylinder side communication portion 165a provided in the cylinder portion 161 of the internal housing 16 and a bottom side communication portion 165b provided in the bottom portion 163a. By changing the ratio of the opening areas of the cylinder side communication portion 165a and the bottom side communication portion 165b, the cooling effect of the refrigerant on the electric motor 50 can be adjusted.

For example, if the heat resistance grade of the electric motor 50 is low, the cooling effect of the refrigerant on the electric motor 50 can be improved by providing only the bottom communication part 165b on the inner housing 16.

On the other hand, if the electric motor 50 has a high heat resistance grade, providing only the cylinder side communication part 165a in the inner housing 16 can prevent foreign matter from entering the electric motor 50. Even in this case, the electric motor 50 can be cooled by heat conduction through the inner housing 16.

(3) The inside of the internal housing 16 and the gap space 164 are partitioned by the tube portion 161 and the support portion 163 below the axis CL of the rotating shaft 20 in the vertical direction Dg so that the inside and outside of the internal housing 16 are not in communication with each other. This makes it possible to prevent the liquid refrigerant that has accumulated on the lower side of the gap space 164 from flowing into the inside of the internal housing 16.

(4) A refrigerant suction passage 38, a refrigerant introduction passage 45, and a communication passage 19 are provided inside the housing 10. This allows the lubricating oil in the gap space 164 to be guided to the compression section 30 side via the communication passage 19, thereby preventing the lubricating oil from accumulating in the gap space 164.

(5) The communication passage 19 is a throttle passage with a smaller cross-sectional area than the refrigerant introduction passage 45. This makes it possible to appropriately guide the lubricating oil in the gap space 164 to the compression section 30 while suppressing the flow of liquid refrigerant into the compression section 30. As a result, abnormal wear and seizure of the sliding parts of the compression section 30 can be prevented.

(6) The refrigerant inlet passage 45 is provided below the axis CL of the rotating shaft 20 in the vertical direction Dg. In this way, the flow of refrigerant through the refrigerant inlet passage 45 can suck the lubricating oil on the lower side of the housing 10 into the compression section 30.

(7) A separation plate 18 is disposed in the gap space 164, which causes the refrigerant introduced into the gap space 164 from the suction port 127 to collide with the separation plate 18, thereby accelerating gas-liquid separation of the refrigerant. In this way, the refrigerant can be caused to collide with the separation plate 18 in the gap space 164, thereby accelerating gas-liquid separation of the refrigerant.

When the rotor 52 of the electric motor 50 rotates as shown by the solid arrow in Figure 7, a swirling flow of the refrigerant occurs inside the housing 10 in the direction of rotation of the rotor 52, as shown by the dotted arrow in Figure 7, and the liquid refrigerant may be stirred up upward.

On the other hand, if a separation plate 18 is placed in the gap space 164, the liquid refrigerant that has accumulated on the lower side of the gap space 164 can be prevented from being swirled upward by the swirling flow of the refrigerant.

(8) The motor housing 12 is provided with a protrusion 166 that protrudes toward the rotating shaft 20 and extends in the axial direction Dax of the rotating shaft 20. This also prevents the liquid refrigerant that has accumulated on the lower side of the gap space 164 from being swirled upward by the swirling flow of the refrigerant.

(9) The compressor ECP of this embodiment has a double-supported structure in which the rotating shaft 20 is supported by the first bearing portion 411 and the second bearing portion 17. This allows the sliding area of each of the bearing portions 411, 17 to be set short, making it easier to steadily supply lubricating oil to the entire sliding surface under conditions of low to high rotation speeds of the rotating shaft 20, thereby ensuring reliability.

Furthermore, the compressor ECP of this embodiment has the following features:

(10) If the internal housing 16 is simply cylindrical with both ends open, when the stator 54 vibrates, the internal housing 16 may vibrate in response to the vibration, resulting in slight deformation. Such deformation is undesirable because it increases the vibration transmitted from the internal housing 16 to the motor housing 12. The same is true when the internal housing 16 is configured to partially support the stator 54 with multiple plate-shaped support pieces.

In contrast, the compressor ECP of this embodiment has an internal housing 16 that is generally cup-shaped, with a tubular portion 161, a support portion 163, and a flange portion 162. This makes it easier to ensure rigidity compared to a simple cylindrical shape, and can suppress deformation of the internal housing 16 due to vibration of the stator 54.

In addition, since the support portion 163 is integrally formed with the cylindrical portion 161 of the inner housing 16, the rigidity of the support portion 163 can be increased, and deformation due to the load received by the second bearing portion 17 from the rotating shaft 20 can be further suppressed. This makes it possible to reduce the amount of imbalance of the axis center CL of the rotating shaft 20.

(11) The compressor ECP is structured so that the inner housing 16, shaft support member 40, and compression section 30 are fixed to the step surface 123 of the motor housing 12. This makes it possible to reduce the contact area between the inner housing 16 and compression section 30 and the motor housing 12 and discharge housing 14, compared to when the stator 54 and compression section 30 are fixed to the inner circumferential surfaces of the motor housing 12 and discharge housing 14. This makes it difficult for vibrations of the stator 54 and compression section 30 to be transmitted to the motor housing 12 and discharge housing 14, thereby suppressing sound and vibrations radiated to the outside of the motor housing 12 and discharge housing 14.

(12) The inner housing 16 is made of the same metal material as the stator 54. This makes it possible to prevent the fixed state between the inner housing 16 and the stator 54 from becoming unstable due to the difference in the linear expansion coefficient between the inner housing 16 and the stator 54. For example, when the stator 54 is fitted and fixed to the inner circumferential surface of the inner housing 16, the tightening margin can be set appropriately.

Here, "the same kind of metallic material" means metallic materials that have the same most abundant element in their chemical composition. Note that the term "same kind of metallic material" includes not only metallic materials that have the exact same chemical composition, but also those that have the same designation in standards.

(13) When the stator 54 is fixed to the motor housing 12 and discharge housing 14 that constitute the outer housing by shrink fitting, it is necessary to set the shrink fit interference large, taking into account deformation due to pressure inside the housing 10.

In contrast, if the stator 54 is fixed to the inner housing 16 as in this embodiment, the motor housing 12 and the discharge housing 14 can be simplified. Also, if the stator 54 is fixed to the inner housing 16, restrictions on the shapes of the motor housing 12 and the discharge housing 14 can be reduced. This makes it possible to connect multiple components, such as a pressure adjustment valve, a refrigerant path, a water path, and a heat exchanger, to the motor housing 12 and the discharge housing 14.

Here, the pressure from inside the motor housing 12 acts on both the inner and outer circumferential surfaces of the tubular portion 161 of the internal housing 16, so the pressure acting on the tubular portion 161 is offset. This makes it difficult for the tubular portion 161 to deform due to the pressure from inside the motor housing 12. This makes it possible to reduce the tightening margin associated with shrink-fitting or press-fitting the stator 54 into the tubular portion 161 of the internal housing 16.

Second Embodiment
Next, a second embodiment will be described with reference to Figures 9 and 10. In this embodiment, differences from the first embodiment will be mainly described.

As shown in FIG. 9, the motor housing 12 of this embodiment does not have the step surface 123 described in the first embodiment, and the inner diameter of the first outer peripheral wall portion 122 is approximately constant. In addition, the discharge housing 14 has a second outer peripheral wall portion 142 extending to the other side in the axial direction Dax so that the fixed scroll 32 and discharge plate 36 are housed inside. The motor housing 12 and discharge housing 14 of this embodiment are fixed by fastening bolts 15 with their respective opening edges abutting against the shaft support member 40.

The shaft support member 40 has an outer diameter of the large diameter portion 42 that is approximately the same as the outer diameter of the motor housing 12 and the outer diameter of the discharge housing 14. The large diameter portion 42 has an insertion hole SH through which the fastening bolt 15 is inserted at a portion facing the opening edge of the motor housing 12 and the discharge housing 14 in the axial direction Dax. The shaft support member 40 is fixed to the motor housing 12 and the discharge housing 14 by the fastening bolt 15 while being sandwiched between the motor housing 12 and the discharge housing 14.

The shaft support member 40 is provided with a refrigerant introduction passage 45. The refrigerant introduction passage 45 is a passage that guides the refrigerant from the inside of the internal housing 16 to the compression section 30. The refrigerant introduction passage 45 is provided obliquely penetrating the shaft support member 40. Specifically, the opening of the refrigerant introduction passage 45 on the internal housing 16 side is positioned radially inward of the opening on the compression section 30 side.

In addition, the shaft support member 40 is formed with a communication passage 46 that connects the gap space 164 with the refrigerant introduction passage 45. The communication passage 46 extends along the axial direction Dax so as to intersect with the refrigerant introduction passage 45. The communication passage 46 is a throttle passage with a smaller cross-sectional area than the refrigerant introduction passage 45.

The internal housing 16 does not include the flange portion 162 described in the first embodiment. The outer diameter of the internal housing 16 is the same size as the outer diameter of the compression section 30. The internal housing 16 has a cylindrical portion 161 with a thickness in the radial direction Dr that is greater than that described in the first embodiment. The internal housing 16 has multiple female threaded holes formed on the opening edge of the cylindrical portion 161, into which the mounting bolts 37 can be screwed.

The inner housing 16 is fixed to the large diameter portion 42 of the shaft support member 40 together with the fixed scroll 32 and the discharge plate 36 by screwing the mounting bolt 37 into the female threaded hole provided in the cylindrical portion 161. In this embodiment, the inner housing 16 and the compression portion 30 are fixed to the motor housing 12 and the discharge housing 14 via the shaft support member 40.

The motor housing 12 also has an intake port 127 at a location facing the internal housing 16. Specifically, the intake port 127 is provided at a side location of the first outer peripheral wall portion 122 of the motor housing 12 facing the internal housing 16. Instead, no separation plate 18 is disposed in the gap space 164. As a result, the gap formed between the first bottom wall portion 121 of the motor housing 12 and the support portion 163 of the internal housing 16 is smaller than in the first embodiment. This contributes to a reduction in the size of the compressor ECP in the axial direction Dax.

Next, the operation of the compressor ECP will be described with reference to FIG. 10. When the stator 54 of the electric motor 50 is supplied with power and the rotor 52 and the rotating shaft 20 rotate, the refrigerant that has passed through the evaporator EV is sucked into the inside of the housing 10 through the suction port 127.

Specifically, as shown by arrow FR1 in FIG. 10, the refrigerant is introduced from the suction port 127 into the gap space 164 formed between the motor housing 12 and the inner housing 16, and then collides with the inner housing 16 to separate the gas and liquid. The refrigerant is then introduced into the inside of the inner housing 16 via the internal/external communication part 165. The gas refrigerant, which has a low specific gravity, is introduced into the inside of the inner housing 16 via the internal/external communication part 165, while the liquid refrigerant, which has a high specific gravity, is stored in the gap space 164.

The refrigerant introduced inside the internal housing 16 passes through the gaps between the various components of the electric motor 50 and the refrigerant introduction passage 45 provided between the motor housing 12 and the shaft support member 40. The refrigerant passing through the refrigerant introduction passage 45 flows into the refrigerant suction passage 38 formed on the outer periphery of the fixed scroll 32, as shown by the arrow FR2 in FIG. 10. At this time, the liquid refrigerant containing the lubricating oil stored in the gap space 164 is sucked into the refrigerant suction passage 38 through the communication passage 46 by the refrigerant flow from the refrigerant introduction passage 45 toward the refrigerant suction passage 38.

The refrigerant that flows into the refrigerant suction passage 38 is sucked into the working chamber 31. The refrigerant supplied to the working chamber 31 is compressed as the volume of the working chamber 31 decreases. When the pressure inside the working chamber 31 reaches the valve opening pressure of the reed valve, the refrigerant compressed in the working chamber 31 is discharged from the discharge hole 323 of the fixed scroll 32 to the muffler chamber 361, as shown by the arrow FR3 in FIG. 10. The refrigerant discharged to the muffler chamber 361 flows from the outlet provided in the discharge plate 36 to the inside of the discharge housing 14, and is then discharged from the discharge port provided in the discharge housing 14 as discharge refrigerant for the compressor ECP.

Otherwise, it is the same as the first embodiment. The compressor ECP of this embodiment can obtain the same effects as the first embodiment, which are achieved from a common configuration or an equivalent configuration to the first embodiment.

The compressor ECP of this embodiment also has the following features:

(1) The motor housing 12 is provided with a suction port 127 at a location facing the inner housing 16. In this way, the refrigerant that passes through the suction port 127 can be caused to collide with the inner housing 16, promoting gas-liquid separation of the refrigerant. This configuration can be easily achieved without the need for additional components.

(2) The compressor ECP can be configured to be smaller than that described in the first embodiment because the outer diameter of the inner housing 16 and the outer diameter of the compression section 30 can be made the same size.

In addition, the inner housing 16 and the compression section 30 are attached to the opening edges of the motor housing 12 and the discharge housing 14 via the shaft support member 40, so the effects of vibration of the inner housing 16 and the compression section 30 can be reduced. As a result, the compressor ECP can be made to have low vibration and low noise.

(Modification of the second embodiment)
In the compressor ECP of the second embodiment, the suction port 127 is provided in a side portion of the first outer peripheral wall portion 122 of the motor housing 12 that faces the inner housing 16, but is not limited thereto. For example, the compressor ECP may have the suction port 127 provided in a bottom portion of the first bottom wall portion 121 of the motor housing 12 that faces the inner housing 16. In this manner, the refrigerant introduced into the inside of the motor housing 12 from the suction port 127 can be caused to collide with the first bottom wall portion 121 of the inner housing 16, thereby efficiently separating the refrigerant into gas and liquid form. As a result, liquid compression in the compressor ECP can be suppressed.

It is desirable that the suction port 127 is provided not in the lower portion that forms the liquid storage space in the first bottom wall portion 121, but in a portion above the lower portion. This prevents the refrigerant introduced into the inside of the motor housing 12 from the suction port 127 from disturbing the liquid level of the liquid refrigerant stored in the liquid storage space or causing the liquid refrigerant to be stirred up upward.

Here, the suction port 127 may be formed in a portion of the first bottom wall portion 121 or the first outer peripheral wall portion 122 that forms a liquid storage space, but in this case, it is desirable that the refrigerant passing through the suction port 127 is guided to the upper side inside the motor housing 12. Such a structure can be realized, for example, by connecting a pipe to the suction port 127 in a manner that protrudes upward. This also promotes gas-liquid separation of the refrigerant and suppresses liquid compression in the compressor ECP.

Other Embodiments
Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as described below.

The internal housing 16 is not limited to being substantially cup-shaped, and may be, for example, cylindrical. In addition, the internal housing 16 is preferably made of the same metal material as the stator 54, but is not limited to this, and may be made of, for example, a different metal material than the stator 54. A portion of the internal housing 16 may be in contact with the motor housing 12 in the axial direction Dax.

As in the above embodiment, it is desirable to provide a communication flow passage 19 inside the housing 10, but this is not limiting, and the communication flow passage 19 may be omitted. In addition, the communication flow passage 19 may be configured as a flow passage having a flow passage cross-sectional area approximately equal to that of the refrigerant introduction flow passage 45.

As in the above embodiment, it is preferable that the refrigerant introduction passage 45 is provided below the axis CL of the rotating shaft 20 in the vertical direction Dg, but this is not limited thereto, and it may be provided above the axis CL of the rotating shaft 20.

As in the above embodiment, it is preferable that a separation plate 18 is disposed in the gap space 164, but this is not limited thereto, and the separation plate 18 may be omitted. Also, it is preferable that a protrusion 166 is provided on the motor housing 12, but this is not limited thereto, and the protrusion 166 may be omitted.

The first bearing portion 411 and the second bearing portion 17 may be configured as, for example, a rolling bearing instead of a sliding bearing. The second bearing portion 17 may be provided on an element other than the inner housing 16. The compressor ECP may have a cantilever structure in which the rotating shaft 20 is supported by one of the first bearing portion 411 and the second bearing portion 17.

The compression section 30 of the compressor ECP is not limited to a scroll type having a fixed scroll 32 and an orbiting scroll 34, but may be, for example, a piston type or a vane type. A portion of the compression section 30 may be in contact with the discharge housing 14 in the axial direction Dax.

In the above embodiment, the compressor ECP applied to a vehicle air conditioner has been described, but the present invention is not limited thereto, and the compressor ECP can also be applied to other air conditioners, temperature control devices for various devices, and the like. The compressor ECP is not limited to a horizontal structure in which the compression section 30 and the electric motor 50 are arranged in a substantially horizontal direction. The various devices constituting the compressor ECP may be fixed by elements other than bolts. The compressor ECP of the present disclosure is not limited to an accumulator-less cycle, but can also be applied to an accumulator cycle. The refrigerant can be reliably separated into gas and liquid before being sucked into the compression section 30, thereby suppressing liquid compression in the compression section 30. In addition, when the refrigeration cycle device 1 is configured to be set to a hot gas cycle in which high-temperature and high-pressure refrigerant discharged from the compressor ECP is circulated, liquid refrigerant may be transiently supplied to the compressor ECP when switching to the hot gas cycle. In contrast, the compressor ECP of the present disclosure has a liquid storage space inside the compressor ECP, so that liquid compression in the compression section 30 can be suppressed even when switching to the hot gas cycle. The refrigeration cycle device 1 has a cycle configuration in which the refrigerant and air are exchanged with each other in the evaporator EV, but is not limited to this. For example, the cycle may be configured to exchange heat between the refrigerant and water, etc., by using a chiller instead of the evaporator EV.

It goes without saying that in the above-described embodiments, the elements constituting the embodiments are not necessarily essential, except in cases where they are specifically stated as essential or where they are clearly considered essential in principle.

In the above-described embodiments, when numerical values such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers, except when it is expressly stated that they are essential or when they are clearly limited to a specific number in principle.

In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., there is no limitation to those shapes, positional relationships, etc., unless specifically stated otherwise or in principle limited to a specific shape, positional relationship, etc.

(Aspects of the present disclosure)
According to a first aspect of the present disclosure,
The electric compressor is
It is applied to the vapor compression refrigeration cycle (1),
A housing (10);
A rotating shaft (20) accommodated inside the housing;
a compression section (30) that compresses a refrigerant by the rotation of the rotary shaft;
an electric motor (50) having a rotor (52) that rotates integrally with the rotary shaft and a stator (54) that is fixed to the housing, and that drives the compression section;
The housing includes:
an inner housing (16) that accommodates at least a portion of the electric motor and to which the stator is fixed;
an outer housing (12) that accommodates the inner housing and has a suction port (127) for a refrigerant;
a discharge housing (14) through which the refrigerant compressed by the compression section is discharged and which is fixed to the external housing,
The external housing and the internal housing are separated at least partially in the radial direction of the rotating shaft, and the refrigerant that flows into the inside of the external housing from the suction port flows through a gap space (164) formed between the internal housing and the external housing and then is sucked into the compression section.

[Second viewpoint]
The electric compressor according to the first aspect, wherein the internal housing is provided with an internal/external communication section (165) that communicates the inside and outside of the internal housing, and the refrigerant that flows into the inside of the external housing from the suction port flows through the gap space, and then is introduced into the inside of the internal housing via the internal/external communication section and sucked into the compression section.

[Third viewpoint]
The rotating shaft is accommodated inside the housing in such a manner that an axis (CL) of the rotating shaft intersects with a vertical direction,
the internal housing includes a cylindrical tube portion (161) to which the stator is fixed, and a bottom surface portion (163) extending from one end portion (161b) of the tube portion that is located opposite to one end portion (161a) close to the compression portion, so as to approach the rotation shaft;
The electric compressor according to a first aspect, wherein at least one of the cylindrical portion and the bottom portion is provided with an inside-outside communication portion (165) that communicates between the inside and the outside of the inner housing, at a portion located above the axis in the vertical direction.

[Fourth viewpoint]
The electric compressor according to the second or third aspect, wherein the inside of the inner housing and the gap space are partitioned by the cylindrical portion and the bottom portion below the axis in the vertical direction so that the inside and outside of the inner housing do not communicate with each other.

[Fifth viewpoint]
The electric compressor according to any one of the first to fourth aspects, wherein a refrigerant suction passage (38) for drawing a refrigerant into the compression section at a position adjacent to the compression section, a refrigerant introduction passage (45) for guiding a refrigerant from inside the inner housing to the refrigerant suction passage, and a communication passage (19, 46) for communicating the gap space with the refrigerant introduction passage below the axis in the vertical direction are provided inside the housing.

[Sixth Viewpoint]
The electric compressor according to a fifth aspect, wherein the communication passage is a throttle passage having a smaller flow passage cross-sectional area than the refrigerant introduction passage.

[Seventh Viewpoint]
The electric compressor according to the fifth or sixth aspect, wherein the refrigerant introduction passage is provided below the axis in the vertical direction.

[Eighth Viewpoint]
The electric compressor according to any one of the first to seventh aspects, wherein a separation plate (18) is disposed in the gap space, which causes the refrigerant introduced into the gap space from the suction port to collide with each other to promote separation of the refrigerant into gas and liquid.

[Ninth Viewpoint]
The electric compressor according to any one of the first to eighth aspects, wherein the outer housing is provided with the suction port at a portion facing the inner housing.

[Tenth Viewpoint]
The electric compressor according to any one of the first to ninth aspects, wherein the outer housing is provided with a protrusion (166) that protrudes in a direction approaching the rotating shaft and extends in an axial direction of the rotating shaft.

10 Housing 12 Motor housing (outer housing)
14 Discharge housing 16 Inner housing 164 Clearance space 20 Rotating shaft 30 Compression section 50 Electric motor 52 Rotor 54 Stator

Claims (10)

An electric compressor for use in a vapor compression refrigeration cycle (1),
A housing (10);
A rotating shaft (20) accommodated inside the housing;
a compression section (30) that compresses a refrigerant by rotation of the rotary shaft;
an electric motor (50) having a rotor (52) that rotates integrally with the rotary shaft and a stator (54) that is fixed to the housing, and that drives the compression section;
The housing includes:
an inner housing (16) that accommodates at least a portion of the electric motor and to which the stator is fixed;
an outer housing (12) that accommodates the inner housing and has a suction port (127) for a refrigerant;
a discharge housing (14) through which the refrigerant compressed by the compression section is discharged and which is fixed to the external housing,
the external housing and the internal housing are separated at least in a portion of the overlapping portion in the radial direction of the rotating shaft, and a refrigerant that flows into the inside of the external housing from the suction port flows through a gap space (164) formed between the internal housing and the external housing and is then sucked into the compression section. The electric compressor according to claim 1, in which the internal housing is provided with an internal/external communication part (165) that communicates the inside and outside of the internal housing, and the refrigerant that flows into the inside of the external housing from the suction port flows through the gap space (164), and is then introduced into the inside of the internal housing via the internal/external communication part and sucked into the compression section. The rotating shaft is accommodated inside the housing in such a manner that an axis (CL) of the rotating shaft intersects with a vertical direction,
the internal housing includes a cylindrical tube portion (161) to which the stator is fixed, and a bottom surface portion (163) extending from one end portion (161b) of the tube portion that is located opposite to one end portion (161a) close to the compression portion, so as to approach the rotation shaft;
2. The electric compressor according to claim 1, wherein at least one of the cylindrical portion and the bottom portion is provided with an inside-outside communication portion (165) that communicates between the inside and the outside of the inner housing, at a portion located above the axis in the vertical direction. The electric compressor according to claim 3, wherein the inside of the internal housing and the gap space are partitioned by the tubular portion and the bottom surface portion below the axis in the vertical direction so that the inside and outside of the internal housing do not communicate with each other. The electric compressor according to claim 3 or 4, in which a refrigerant suction passage (38) that draws refrigerant into the compression section at a position adjacent to the compression section, a refrigerant introduction passage (45) that introduces refrigerant from the inside of the inner housing to the refrigerant suction passage, and a communication passage (19, 46) that connects the gap space and the refrigerant introduction passage below the axis in the vertical direction are provided inside the housing. The electric compressor according to claim 5, wherein the communication passage is a throttle passage having a smaller flow cross-sectional area than the refrigerant introduction passage. The electric compressor according to claim 5, wherein the refrigerant introduction passage is provided below the axis in the vertical direction. The electric compressor according to any one of claims 1 to 3, wherein a separation plate (18) is disposed in the gap space to promote separation of the refrigerant into gas and liquid by causing the refrigerant introduced into the gap space from the suction port to collide with the refrigerant. The electric compressor according to any one of claims 1 to 3, wherein the suction port is provided in a portion of the outer housing facing the inner housing. The electric compressor according to any one of claims 1 to 3, wherein the outer housing is provided with a protrusion (166) that protrudes toward the rotating shaft and extends in the axial direction of the rotating shaft.

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