JP4529973B2 - Electric compressor - Google Patents

Description

  The present invention relates to an electric compressor in which a compression mechanism section and an electric motor that drives the compression mechanism section are built in a body container and the electric motor is driven by an inverter.

  In this type of electric compressor, an inverter, a compression mechanism section, and an electric motor are partitioned and provided integrally (see, for example, Patent Document 1 or Patent Document 2).

  FIG. 3 is a longitudinal sectional view of the electric compressor described in Patent Document 1. A partition wall 104 is provided to partition the fuselage container 101 into a compression chamber 102 and an inverter chamber 103 in the axial direction, and the compression chamber 102 is compressed. The mechanism unit 105 and the electric motor 106 are accommodated, and the inverter 107 is accommodated in the inverter chamber 103. The inverter 107 faces a certain suction side of the electric motor 106 through the partition wall 104, cools the inverter 107 and the electric motor 106 with the sucked refrigerant, and then flows into the compression mechanism unit 105, which is a typical structure in a so-called low-pressure compressor. It is.

FIG. 4 is a longitudinal sectional view of the electric compressor described in Patent Document 2. An airframe container 112 containing the electric motor 111, an inverter on the opposite side of the electric motor 111 with the compression mechanism 113 and the compression mechanism 113 interposed therebetween. The inverter case 115 that accommodates 114 is fastened with bolts or the like in the axial direction. The suction refrigerant flowing in from the suction port 116 provided in the compression mechanism unit 113 is once guided to the passage 117 provided in the inverter case 115 and exchanges heat with the inverter 114 and then sucked into the compression mechanism unit 113. Is done. Further, the refrigerant gas compressed by the compression mechanism unit 113 cools the electric motor 111 and is then discharged from the discharge port 118 provided in the body container 112. This is a typical structure in a so-called high-pressure compressor.
JP 2000-291557 A JP 2004-183631 A

  However, since the structure described in Patent Document 1 is sucked into the compression section after exchanging heat with the inverter and the high heat-generating parts of the electric motor by the sucked refrigerant, the volume efficiency is lowered due to the rise of the sucked refrigerant temperature, and the compressor Adversely affects performance. Furthermore, since the refrigerant discharged from the compression mechanism section is directly discharged to the outside, if the lubricating oil supplied to the compression mechanism section and accompanying the discharged refrigerant is separated to improve the performance of the refrigeration cycle, the refrigerant is discharged to the outside. Separation is difficult because it is performed only in a short discharge process. For this reason, a full-scale and large-sized separator is required, which causes an increase in the size and weight of the fuselage container.

  On the other hand, in the structure described in Patent Document 2, the suction refrigerant is used only for inverter cooling, and the lubricating oil separation device can be provided by using the empty space of the fuselage container in which the electric motor is accommodated. There are significant advantages in terms of performance and size of the fuselage container. However, in the structure described in Patent Document 2, the suction refrigerant passage provided in the inverter case is divided from the discharge refrigerant passage by a partition wall, so that the cooling area is reduced, and the heating element of the inverter portion is connected to the back of the suction refrigerant passage. It was necessary to devise the arrangement. Further, the suction refrigerant is heated by heat transfer from the partition wall by the high-temperature discharge gas, the cooling capacity is lowered, and the performance is deteriorated due to the volumetric efficiency reduction.

  An object of the present invention is mainly to provide an electric compressor capable of efficiently cooling an inverter without increasing the size of a fuselage container.

In order to solve the above-described conventional problems, a fuselage container including a fixed scroll for sucking, compressing and discharging refrigerant, a compression mechanism having a turning scroll, and an electric motor for driving the compression mechanism, and the electric motor An inverter case with a built-in inverter to drive, and the inverter case and the fixed scroll portion form a suction chamber to cool the heat generating components of the inverter, and the discharge chamber of the fixed scroll is independent in the suction chamber Formed.
As a result, the suction refrigerant can be diffused and flown throughout the suction chamber, and by cooling the entire end face wall of the inverter case, the degree of freedom in arranging the heat generating components of the inverter is increased and a cooling effect can be obtained over a wide range. Therefore, the performance and reliability can be improved.

  The electric compressor of the present invention can improve the cooling efficiency of the inverter parts without increasing the size of the fuselage container, and is severely affected by heating, vibration, etc. from the engine by being directly mounted on the engine such as a hybrid vehicle. Even in an environment, it is possible to operate without impairing performance and reliability.

  According to a first aspect of the present invention, there is provided a fuselage container including a compression mechanism having a fixed scroll and a revolving scroll for sucking, compressing and discharging refrigerant, an electric motor for driving the compression mechanism, and an inverter for driving the electric motor. An electric compressor having a built-in inverter case, wherein the inverter case and the end plate of the fixed scroll form a suction chamber to cool a heat generating component of the inverter, and the fixed scroll is placed in the suction chamber. The discharge chamber is formed independently. As a result, the refrigerant can be diffused and flown throughout the suction chamber, and by cooling the wide range of the inverter case, the degree of freedom of arrangement of the heat generating components of the inverter is increased and a cooling effect is obtained over a wide range. Performance and reliability can be improved.

  In the second invention, in particular, since the discharge chamber of the fixed scroll of the first invention is constituted by a part of the fixed scroll and the lid, it is easy to enter the suction chamber constituted by the inverter case and the fixed scroll portion. The discharge chamber can be provided independently. As a result, the entire end face wall of the inverter case can be cooled over a wide range, and the cooling performance of the heat generating components of the inverter is greatly improved.

  According to the third aspect of the invention, in particular, a groove is provided in the outer peripheral portion of the fixed scroll of the first or second aspect of the invention, and a communication passage for discharging discharge gas is formed between the inner peripheral surface of the machine body container, It is possible to ensure a larger flow path area than providing a discharge hole directly in the fixed scroll. Thereby, the discharge resistance is reduced and the performance is improved.

  According to the fourth aspect of the invention, in particular, the lid of the second or third aspect of the invention is formed using a heat insulating member, so that the influence of heat transfer of the high-temperature discharge gas can be suppressed. Thereby, the cooling effect of the heat-emitting components of the inverter is increased, and the reliability is improved.

  In the fifth aspect of the invention, in particular, by providing the communication passage of the third or fourth aspect below the discharge hole of the fixed scroll, the lubricating oil contained in the discharge gas may stay in the discharge chamber. Can be prevented, and performance and reliability are improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of an electric compressor according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view of a discharge chamber shown in FIG. FIG. 1 shows one example in the case of a horizontal type electric compressor installed sideways by a mounting leg 2 around a body portion of the electric compressor 1. The electric compressor 1 includes a main body casing 3. An electric motor 4 is housed therein, and a compression mechanism 5 that is fitted or press-fitted into the main body casing 3 is driven. The electric motor 4 is driven by an inverter 7 incorporated in an inverter case 6. Further, the main body casing 3 is provided with a liquid storage section 8 for storing a liquid used for lubricating each sliding section including the compression mechanism section 5. The refrigerant to be handled is a gas refrigerant, and lubricating oil 9 is used as a liquid to be used for lubrication of each sliding portion and for sealing the sliding portion of the compression mechanism portion 5.

  The compression mechanism unit 5 of the electric compressor 1 of the present embodiment is of a scroll type. The compression space 10 formed by meshing the fixed scroll 11 having the blades rising from the fixed end plate 11a and the turning end plate 12a and the turning scroll 12 is circular with respect to the fixed scroll 11 via the drive shaft 13 by the electric motor 4. The suction port 15 provided in the inverter case 6 and the main body casing 3 are provided with suction, compression, and discharge to the external cycle of the refrigerant 14 returning from the external cycle by changing the volume accompanying movement when the track is moved. The discharge port 16 is used.

  A main bearing member 20 having a pump 17, a sub-bearing 18, an electric motor 4, and a main bearing 19 is arranged from one axial side wall 3 a side in the main body casing 3. The pump 17 is held from the outer surface of the side wall 3a and is held between the lid body 21 and the pump body 22 that is fitted thereafter, and a pump chamber 22 that leads to the liquid storage section 8 is formed inside the lid body 21 so that the suction passage 23 is formed. Via the liquid reservoir 8. The auxiliary bearing 18 is supported by the side wall 3a, and supports the side connected to the pump 17 of the drive shaft 13. The electric motor 4 is configured such that the stator 4a can be rotationally driven by a rotor 4b that is fixed by shrink-fitting the stator 4a to the main body casing 3 or by an annular member 24 and fixed around the middle of the drive shaft 13. Yes. An oil supply passage 25 is formed inside the drive shaft 13.

  The main bearing member 20 is fixed by a fixed scroll 11 and a bolt (not shown) and is held by an inverter case 6 fitted to the opening side of the main body casing 3, and the compression mechanism portion 5 side of the drive shaft 13 is held on the main bearing. 19 is pivotally supported. Further, the scroll compressor is configured by sandwiching the orbiting scroll 12 between the main bearing member 20 and the fixed scroll 11. Between the main bearing member 20 and the orbiting scroll 12, a rotation restraining portion for preventing the rotation of the orbiting scroll 12, such as an Oldham ring 26, is provided, and the drive shaft 13 is orbited via an eccentric bearing 27. Connected to the scroll 12, the orbiting scroll 12 can be turned on a circular path.

  In the inverter case 6, a suction chamber 28 is formed by airtightly combining a space communicating with the suction port 15 with the fixed end plate 11 a of the fixed scroll 11 using a seal member 11 b. Further, the fixed scroll 11 is provided with a discharge hole 29 and a reed valve 29a, and is opened to the discharge chamber 30 protruding into the suction chamber 28. The discharge chamber 30 communicates with the motor 4 through a communication passage 31 formed by a groove 31 a provided on the outer periphery of the fixed scroll 11 and the main bearing member 20 and an inner peripheral surface of the main casing 3. A through passage 31b is formed in the fixed scroll 11 from the discharge chamber 30 to the groove 31a.

The inverter 7 includes a circuit board 32 and an electrolytic capacitor (not shown) on the opposite surface of the suction chamber 28 on the end wall 6 a of the inverter case 6. In addition, a heating component 33 of an IPM (intelligent power module) including a switching element having a high heat generation degree is mounted on the circuit board 32 so as to be in thermal contact with the end wall 6a. The inverter 7 is electrically connected to the electric motor 4 via a compressor terminal 35 connected by a harness connector 34, and is driven by the inverter 7 while monitoring necessary information such as temperature. is there. A cover 36 is provided so as to cover the inverter 7.

  The discharge chamber 30 will be described with reference to FIG. FIG. 2 is an exploded view of the discharge chamber 30 and is a perspective view with the main body casing 3 and the inverter case 6 removed. The discharge chamber 3 is formed in a part of the space forming the suction chamber 28 using a part of the fixed end plate 11a. In FIG. 2, the discharge chamber 30 has a substantially rectangular side wall 11c formed so as to surround the discharge hole 29 of the fixed end plate 11a, and a lid 37 formed of a heat insulating member in accordance with the side wall 11c with a bolt 38. The suction chamber 28 is configured to be fixed and arranged independently in the suction chamber 28. In the discharge chamber 30, a reed valve 29 a and a reed valve presser 29 b for opening and closing the discharge hole 29 are fixed by bolts 39.

  With the above configuration, the electric motor 4 is driven by the inverter 7, causes the compression mechanism 5 to move in a circular path via the drive shaft 13, and drives the pump 17. At this time, the compression mechanism section 5 is supplied with the lubricating oil 9 of the liquid storage section 8 through the oil supply passage 25 of the drive shaft 13 by the pump 17 and receives the lubrication and sealing action, and the refrigeration cycle through the suction port 15 provided in the inverter case 6. Inhale the return refrigerant from. The sucked refrigerant 14 cools the end wall 6a over a wide range in the space of the suction chamber 28, and after exchanging heat with a heat generating component 33 such as an IPM mounted on the rear surface thereof, the passage of the fixed end plate 11a It flows into the compression space 10 through the hole 40. The refrigerant is compressed in the compression space 10 and discharged from the discharge hole 29 to the discharge chamber 30.

  The refrigerant discharged from the discharge hole 29 to the discharge chamber 30 enters the electric motor 4 side through a communication passage 31 formed between a groove portion 31 a provided in the outer peripheral portion of the fixed scroll 11 and the inner peripheral surface of the main body casing 3. In the long process until the electric motor 4 is cooled and discharged from the discharge port 16 of the main casing 3, the refrigerant is subjected to various gas-liquid separations such as collision, centrifugation, throttling, etc. The auxiliary bearing 18 is also lubricated by the accompanying partial lubricating oil 9.

  As described above, the inverter case 6 and the fixed scroll 11 constitute the suction chamber 28, and the discharge chamber 30 of the fixed scroll 11 is independently formed in the suction chamber 28, whereby the end wall 6 a of the inverter case 6 is formed. By cooling in a wide range, a cooling effect can be obtained without being influenced by the arrangement of the heat generating components 33 on the circuit board 32.

  Further, since the discharge chamber 30 is constituted by a part of the fixed scroll 11 and the lid 37, the discharge chamber 30 can be easily and independently provided in the suction chamber 28 constituted by the inverter case 6 and the fixed scroll 11. Can be provided.

  In addition, since the groove 31a is provided in the outer peripheral portion of the fixed scroll 11 and the communication passage 31 for discharging the discharge gas is formed between the inner peripheral surface of the main body casing 3 and the discharge hole is directly provided in the fixed scroll 11. A large flow path area can be secured, and the discharge resistance can be reduced to improve performance.

  In addition, since the lid body 37 is formed using a heat insulating member, the influence of heat transfer from the high-temperature discharge gas to the low-temperature intake gas can be suppressed.

  Further, the communication passage 31 can be disposed below the discharge hole 29 to prevent the lubricant 9 from staying in the discharge chamber 30.

  As described above, in the electric compressor according to the present invention, the inverter cooling surface is expanded as compared with the conventional electric compressor with a built-in inverter, and the reliability of the electronic components is improved. As a result, it can be mounted on an engine and can be widely applied to environmental vehicles such as hybrid vehicles.

The longitudinal cross-sectional view of the electric compressor in Embodiment 1 of this invention 1 is an exploded perspective view of the discharge chamber shown in FIG. Vertical section of a conventional electric compressor Vertical section of a conventional electric compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric compressor 3 Main body casing 4 Electric motor 5 Compression mechanism part 6 Inverter case 6a End wall part 7 Inverter 11 Fixed scroll 11a Fixed end plate 12 Orbiting scroll 14 Refrigerant 28 Suction chamber 30 Discharge chamber 31 Communication channel 31a Groove part 37 Cover body

Claims (5)

A fuselage container including a fixed scroll for sucking, compressing and discharging refrigerant, a compression mechanism having a revolving scroll, an electric motor for driving the compression mechanism, and an inverter case having an inverter for driving the electric motor. In the electric compressor provided, a suction chamber is formed by the inverter case and the end plate of the fixed scroll so as to cool a heat generating component of the inverter, and the discharge chamber of the fixed scroll is independently provided in the suction chamber. An electric compressor characterized by being formed. The electric compressor according to claim 1, wherein the discharge chamber includes a part of a fixed scroll and a lid. The refrigerant gas discharged into the discharge chamber is discharged into a space in which the electric motor is built through a communication passage formed between a groove provided in the outer peripheral portion of the fixed scroll and the inner peripheral surface of the fuselage container. The electric compressor according to claim 1 or 2, characterized in that. The electric compressor according to claim 2, wherein the lid is formed using a heat insulating member. 5. The electric compressor according to claim 3, wherein the communication passage is provided below the discharge hole of the fixed scroll.