JP2010106683A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve volumetric efficiency at the time of compression in a compressor by inhibiting heat of discharge fluid of a compression mechanism from being transmitted to sucked fluid. <P>SOLUTION: This compressor has the compression mechanism 20 sucking and compressing fluid held in a housing 10. The housing 10 comprises a motor housing 11 in which at least fluid sucked by the compression mechanism 20 flows, and a rear housing 12 covering a discharge port (25) discharging fluid compressed by the compression mechanism 20. A heat insulating member 100 comprising a low heat conductivity member 101 having lower heat conductivity than the motor housing 11, a first gasket 102 sealing a part between the motor housing 11 and the low heat conductivity member 101, and a second gasket 103 sealing a part between the rear housing 12 and the low heat conductivity member 101 is interposed between the motor housing 11 and the rear housing 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a compressor that compresses fluid by operation of a compression mechanism housed in a housing.

Conventionally, in a compressor in which a compression mechanism for sucking and compressing fluid and discharging it into a discharge chamber is housed in a housing, in order to suppress the heat of the discharge fluid in the discharge chamber from being transferred to the suction fluid sucked into the compression mechanism, A discharge chamber provided with heat insulation means is known (for example, Patent Document 1). In this patent document 1, since the suction fluid flows through the housing, a part of the discharge chamber is formed by a member (rear plate) different from the housing, and heat insulating means is provided on the rear plate. The heat insulating means provided on the rear plate suppresses the heat of the discharge fluid in the discharge chamber from being transmitted to the suction fluid (the suction fluid is heated by the heat of the discharge fluid).
JP 2005-146958 A

  However, in the compressor described in Patent Document 1, heat tends to be trapped in the discharge chamber. Therefore, the heat trapped in the discharge chamber is transferred to components (such as the housing of the compression mechanism) other than the heat insulating member provided on the rear plate, and the temperature of the suction fluid rises through the component other than the heat insulating member. There is. There has been a problem that the volumetric efficiency at the time of compression in the compressor decreases due to the temperature rise of the suction fluid.

  In view of the above points, an object of the present invention is to improve the volume efficiency at the time of compression in a compressor by suppressing the heat of the discharge fluid of the compression mechanism from being transmitted to the suction fluid.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a compressor in which a compression mechanism (20) for sucking and compressing fluid is housed in a housing (10), and the housing (10) A suction side housing (11) through which at least a fluid sucked into the compression mechanism (20) flows; and a discharge side housing (12) covering a discharge port (25) for discharging the fluid compressed by the compression mechanism (20); A low thermal conductivity member (101) having a lower thermal conductivity than the suction side housing (11), between the suction side housing (11) and the discharge side housing (12), and the suction side housing (11) and the low thermal conductivity member (101) are sealed between the first gasket (102), and the discharge side housing (12) and the low thermal conductivity member (101) are sealed between the second gasket. (103), characterized in that an intervening insulating member (100) made of.

  Thus, the low thermal conductivity member (101), the first and second gaskets (102, 103) are provided between the suction side housing (11) and the discharge side housing (12) constituting the housing (10) of the compressor. ) Is interposed, it is possible to suppress the heat of the discharge fluid from being transmitted to the suction fluid through the discharge side housing (12) and the suction side housing (11). Thereby, the compression efficiency at the time of compression of a compressor can be improved.

  The invention according to claim 2 further includes an electric motor (30) for driving the compression mechanism (20) in the invention according to claim 1, and the electric motor (30) is provided in the suction side housing (11). It is stored in.

  According to this, the discharge capacity of the compression mechanism (20) can be easily adjusted, and the electric motor (30) can be cooled by the fluid sucked into the compression mechanism (20).

  Specifically, as in the invention described in claim 3, in the invention described in claim 1 or 2, the compression mechanism (20) is moved relative to the fixed scroll (21) fixed to the housing (10). By turning the orbiting scroll (22), a scroll type compression mechanism that compresses fluid in the compression chamber (23) formed between the fixed scroll (21) and the orbiting scroll (22) can be obtained. .

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram of an axial cross section of an electric compressor according to an embodiment, and FIG. 2 is a partially enlarged view of a portion A in FIG.

  As shown in FIG. 1, in this embodiment, the electric compressor 1 provided with the compression mechanism 20, the electric motor 30, etc. in the housing 10 is employ | adopted as a compressor.

  Further, the compressor is applied to a subcritical refrigeration cycle (not shown) using a chlorofluorocarbon-based or HC-based alternative chlorofluorocarbon as a refrigerant (fluid). As is well known, the refrigeration cycle includes a compressor that sucks and compresses refrigerant, a condenser that condenses the high-temperature and high-pressure refrigerant compressed by the compressor, an expansion valve that decompresses the refrigerant condensed by the condenser, and a pressure that is reduced by the expansion valve. It consists of an evaporator that evaporates the refrigerant.

  The housing 10 of the electric compressor 1 includes a substantially cup-shaped motor housing 11 that houses the compression mechanism 20 and the electric motor 30, and a substantially cup-shaped rear housing 12 that covers the opening side of the motor housing 11. The motor housing 11 and the rear housing 12 are connected by fastening means such as a bolt 10a with a heat insulating member 100 described later interposed therebetween. Both housings 11 and 12 are made of an aluminum alloy die casting.

  In the motor housing 11, an electric motor 30 is disposed on the front wall portion 11a side (closed side) of the motor housing 11, and a compression mechanism 20 is disposed on the rear housing 12 side (opening side). The motor housing 11 is rotatably supported by a shaft support member 13 disposed between the electric motor 30 and the compression mechanism 20 and bearings 14 a and 14 b disposed on the front wall portion 11 a of the motor housing 11. A shaft 15 is provided.

  First, the electric motor 30 of the electric compressor 1 will be described. The electric motor 30 of the present embodiment employs an inner rotor type electric motor. Specifically, the electric motor 30 uses a brushless DC motor including a stator 31 fixed to the motor housing 11, a rotor 32 rotating in the stator 31, and the like.

  The stator 31 includes a stator core (yoke) 31a made of a magnetic material such as a silicon steel plate, and windings (coils) 31b wound around the stator core 31a. Further, the rotor 32 is coupled to rotate integrally with the shaft 15. The rotor 32 is provided with a plurality of permanent magnets (rotor magnetic poles) on the outer peripheral side which is the surface facing the stator core 31a of the stator 31.

  Here, on the outer peripheral surface of the motor housing 11 of the electric compressor 1, an inverter device 40 that controls driving of the electric motor 30 is integrally disposed. The inverter device 40 includes a motor drive circuit (not shown) that switches the winding 31b of the stator 31 that allows current to flow depending on the rotational position of the rotor 32 in the electric motor 30, and a control circuit that controls the current supplied to the motor drive circuit. And an output terminal 41 for electrically connecting to the electric motor 30. The output terminal 41 is electrically connected to the stator 31 of the electric motor 30 through a through hole 11b formed in a portion corresponding to the stator 31 on the outer peripheral surface of the motor housing 11.

  The circuit of the inverter device 40 will be briefly described. A current supplied from a DC power source (not shown) such as a battery via a capacitor is converted into a pair of series-connected semiconductor switching elements (U and X, V and Y). , W and Z) are taken out as currents for the U phase, V phase, and W phase of the three-phase AC motor and supplied to the electric motor 30. And the electric current supplied to the electric motor 30 is controlled by the control circuit by the command from the main controller (not shown).

  Next, as the compression mechanism 20 of the electric compressor 1, a known scroll type compression mechanism having a fixed scroll member 21 and a turning scroll member 22 is employed.

  The fixed scroll member 21 has a cylindrical outer peripheral wall 21b projecting toward the front wall 11a side on the outer peripheral side of the disc-shaped substrate 21a, and a fixed spiral on the inner peripheral side of the outer peripheral wall 21b in the substrate 21a. The wall 21c protrudes toward the electric motor 30 side.

  A rotating scroll member 22 is supported on a crankshaft 15 a provided at one end of the shaft 15 on the side of the shaft support member 13 via a bush 16 and a bearing 17 so as to be relatively rotatable so as to face the fixed scroll member 21. ing. The orbiting scroll member 22 has an orbiting spiral wall 22b protruding from a disk-shaped substrate 22a toward the substrate 21a of the fixed scroll member 21.

  The fixed scroll member 21 and the orbiting scroll member 22 are meshed with each other by the fixed spiral wall 21c and the orbiting spiral wall 22b, and the front end surfaces of the spiral walls 21c and 22b are the opposite scroll members 21 and 22, respectively. It is in contact with the substrates 21a and 22a. Accordingly, the substrate 21 a of the fixed scroll member 21, the fixed spiral wall 21 c, the substrate 22 a of the orbiting scroll member 22, and the orbiting spiral wall 22 b define the compression chamber 23.

  Between the substrate 22a of the orbiting scroll member 22 and the shaft support member 13 facing the substrate 22a, an annular hole 13a provided in the shaft support member 13 and a projecting projection of the orbiting scroll member 22 are loosely fitted into the annular hole 13a. A well-known rotation prevention mechanism 24 including a pin 22c is provided.

  A suction port (not shown) for sucking a refrigerant that connects the inside of the compression chamber 23 and the side of the electric motor 30 in the motor housing 11 is formed on the outermost peripheral side of the orbiting spiral wall 22b of the substrate 22a in the orbiting scroll member 22. ing. Here, the suction port is connected to the external refrigerant circuit via a suction passage (not shown) such as a groove formed in the inner wall of the motor housing 11 on the electric motor side, a gap of the electric motor 30 in the motor housing 11, and the like. It communicates with the external piping connected to the evaporator. Accordingly, the motor housing 11 constitutes a suction side housing through which the suction refrigerant sucked into the compression mechanism 20 flows.

  A discharge port 25 for discharging the refrigerant compressed in the compression chamber 23 is formed substantially at the center of the substrate 21 a of the fixed scroll member 21. The discharge port 25 is provided with a discharge valve 26 that opens to the discharge chamber 27 side described later. The discharge valve 26 has a maximum opening regulated by a stopper (not shown), and is fixed to the fixed scroll member 21 by fastening means (not shown) such as a bolt.

  The fixed scroll member 21 has a cylindrical cylindrical wall portion 21 d that protrudes toward the opening side of the motor housing 11. The cylindrical wall portion 21 d of the fixed scroll member 21 is provided so as to surround the discharge port 25.

  Here, a cylindrical wall portion 12 a having a cylindrical shape projects from the rear housing 12 connected to the motor housing 11 toward the opening side of the motor housing 11. The distal end surface of the cylindrical wall portion 21d of the fixed scroll member 21 is in contact with the distal end surface of the cylindrical wall portion 12a of the rear housing 12, and the fluid flows from the discharge port of the compression mechanism 20 by the cylindrical wall portions 21d and 12a. A discharge chamber 27 is defined. Accordingly, the rear housing 12 constitutes a discharge-side housing that covers the discharge port 25 that discharges the discharge refrigerant compressed by the compression mechanism 20.

  The discharge chamber 27 communicates with external piping connected to a condenser of an external refrigerant circuit (not shown) via a discharge passage 12c formed in the rear wall portion 12b of the rear housing 12. An oil separator 18 is provided in the discharge passage 12 c of the rear housing 12. The oil contained in the refrigerant discharged from the compression mechanism 20 is separated by the oil separator 18 and returned to the suction port, the suction passage, and the like via the oil return passage 19.

  As described above, the motor housing 11 and the rear housing 12 of the present embodiment are connected by fastening means such as bolts 10a with the heat insulating member 100 interposed. The heat insulating member 100 is provided in order to suppress the heat of the discharged refrigerant in the discharge chamber 27 defined by the rear housing 12 and the fixed scroll member 21 from being transmitted from the rear housing 12 to the motor housing 11. The heat insulating member 100 is formed with a through hole (not shown) for inserting the bolt 10a.

  Specifically, as shown in FIG. 2, the heat insulating member 100 is configured by a three-layer heat insulating ring including a low thermal conductivity member 101 and first and second gaskets 102 and 103. Here, the low thermal conductivity member 101 and the first and second gaskets 102 and 103 are formed in a ring shape corresponding to the mating surfaces of the motor housing 11 and the rear housing 12.

  The low thermal conductivity member 101 is made of a material having a lower thermal conductivity than the material (aluminum alloy) of the motor housing 11. As a material of the low thermal conductivity member 101, for example, a resin material such as PPS (polyphenylene sulfide), ABS (acrylonitrile-butadiene-styrene plastic), PBT (polybutylene terephthalate), or a metal material such as stainless steel or titanium is adopted. Can do.

  Here, when stainless steel is used as the material of the low thermal conductivity member 101, the thickness of the stainless steel, that is, the axial dimension of the shaft 15, can be 10 to 20 times that of the gaskets 102 and 103.

  According to this, the thermal conductivity between the motor housing 11 and the rear housing 12 is lowered as compared with the configuration in which one gasket is interposed between the motor housing 11 and the rear housing 12 as in the conventional compressor. Can be made.

  The first gasket 101 is provided for sealing between the motor housing 11 and the low thermal conductivity member 101, and the second gasket 102 is for sealing between the rear housing 12 and the low thermal conductivity member 101. Is provided.

  In the electric compressor 1 having the above configuration, when a current is supplied from the inverter device 40 to the electric motor 30, the rotor 32 of the electric motor 30 rotates in the stator 31, and the compression mechanism 20 is driven.

  By driving the compression mechanism 20, the refrigerant is supplied from the external pipe into the compression mechanism 20 through the suction passage and the suction port in the motor housing 11. Then, the refrigerant is compressed to high temperature and high pressure by the compression mechanism 20. The refrigerant compressed by the compression mechanism 20 is discharged into the discharge chamber 27 through the discharge port 25 formed in the fixed scroll member 21 and led out to the external pipe through the discharge passage 12c formed in the rear housing 12. .

  The discharge chamber 27 from which the discharge refrigerant is discharged from the discharge port 25 is defined by the fixed scroll member 21 and the rear housing 12, and the heat of the high-temperature and high-pressure discharge refrigerant in the discharge chamber 27 is applied to the rear housing 12. The rear housing 12 becomes hot.

  Here, the housing 10 of the conventional compressor 1 is configured to connect the motor housing 11 and the rear housing 12. Therefore, the heat of the rear housing 12 is transmitted to the suction refrigerant inside the motor housing 11 through the motor housing 11, and the suction refrigerant is heated.

  As described above, in the present embodiment, since the motor housing 11 through which the suction refrigerant flows and the rear housing 12 that covers the discharge port 25 are connected via the heat insulating member 100, the heat of the discharge refrigerant is sucked through the housing 10. It is possible to suppress the transmission to. Thereby, the rise in the temperature of the suction refrigerant can be suppressed by the heat of the discharged refrigerant, and the reduction in volume efficiency during compression due to the decrease in the refrigerant density of the suction refrigerant can be suppressed.

  Further, the motor housing 11 and the rear housing 12 in which the inverter device 40 is disposed on the outer peripheral surface are connected via the heat insulating member 100, so that the heat of the discharged refrigerant flows through the housings 11 and 12. It is possible to suppress the transmission to.

  Further, since the compressor is the electric compressor 1 in which the compression mechanism 20 is driven by the electric motor 30 in the motor housing 11, the discharge capacity of the compression mechanism 20 can be easily adjusted. Furthermore, by adopting a configuration in which low-temperature and low-pressure suction refrigerant flows in the motor housing 11, the electric motor 30 can be cooled by the suction refrigerant.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows.

  (1) In the above-described embodiment, the compressor housing 10 is made of an aluminum alloy die casting, but other materials, processing methods, and the like may be used. In this case, as the material of the low thermal conductivity member 101, a material having a lower thermal conductivity than the housing (motor housing 11) of the compressor 10 may be selected.

  (2) In the above-described embodiment, the compressor housing 10 includes the motor housing 11 corresponding to the suction-side housing and the rear housing 12 corresponding to the discharge-side housing. However, the present invention is not limited to this. It is not something. For example, the suction side housing may be configured such that a housing for storing the compression mechanism 20 and a housing for storing the motor 30 are connected.

  (3) In the above-described embodiment, the inner rotor type electric motor is adopted as the electric motor 30. However, the present invention is not limited to this, and other electric motors such as an outer rotor type electric motor may be adopted.

  (4) In the above-described embodiment, the inverter device 40 is disposed on the outer peripheral surface of the motor housing 11 (the outer peripheral surface in the radial direction of the shaft 15), but the present invention is not limited to this. For example, the compression mechanism 20, the electric motor 30, and the inverter device 40 may be arranged in series in the axial direction of the shaft 15 and connected, or the inverter device 40 may be arranged independently of the compressor.

  (5) Although the compressor has been described as the electric compressor 1 having the electric motor 30 in the above-described embodiment, for example, the compressor is driven by an external prime mover such as an internal combustion engine (engine) mounted on a vehicle. Also good.

  (6) In the above-described embodiment, the example in which the scroll type compressor mechanism is adopted as the compression mechanism 20 has been described. However, the present invention is not limited to this, and may be a piston type or vane type compression mechanism, for example.

  (7) In the above-described embodiment, the example in which the compressor is applied to a subcritical refrigeration cycle using a chlorofluorocarbon-based or HC-based alternative chlorofluorocarbon as a refrigerant has been described. The present invention may be applied to a supercritical refrigeration cycle using carbon or the like. The compressor is not limited to the refrigeration cycle and may be applied to other devices.

It is a mimetic diagram of an axial section of a compressor concerning an embodiment. It is the elements on larger scale of the A section of FIG.

Explanation of symbols

1 Electric compressor (compressor)
10 Housing 11 Motor housing (suction side housing)
12 Rear housing (discharge side housing)
20 compression mechanism 30 electric motor 100 heat insulation member 101 low thermal conductivity member 102 first gasket 103 second gasket

Claims (3)

A compressor in which a compression mechanism (20) for sucking and compressing fluid is housed in a housing (10),
The housing (10) includes at least a suction-side housing (11) through which fluid sucked into the compression mechanism (20) flows, and a discharge port (25) that discharges fluid compressed by the compression mechanism (20). A discharge-side housing (12) covering the
Between the suction side housing (11) and the discharge side housing (12), a low thermal conductivity member (101) having a lower thermal conductivity than the suction side housing (11), the suction side housing (11). And a first gasket (102) that seals between the low thermal conductivity member (101) and a second gasket (103) that seals between the discharge side housing (12) and the low thermal conductivity member (101). ). A compressor characterized by interposing a heat insulating member (100). An electric motor (30) for driving the compression mechanism (20);
The compressor according to claim 1, wherein the electric motor is accommodated in the suction side housing (11).   The compression mechanism (20) rotates the orbiting scroll (22) with respect to the fixed scroll (21) fixed to the housing (10), whereby the fixed scroll (21) and the orbiting scroll (22). The compressor according to claim 1 or 2, wherein the compressor is a scroll type compression mechanism that compresses fluid in a compression chamber (23) formed therebetween.

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