JP2007224809A - Electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric compressor having an inverter built therein capable of being operated without deterioration of reliability and performance even under high temperature and intense vibration environment such as engine direct mount. <P>SOLUTION: A main body casing 3 is provided with a compression mechanism part 4, a motor 5 driving the compression part 4 and a motor drive circuit part 101. The compression mechanism part 4 is provided with a compression part and a suction passage 61 cooling a heat generating body 105 of the motor drive circuit part 101 through a partition part 112. The suction passage 61 is constructed to make fluid 30 flowing in from a suction pipe 8 flow to a section opposite to other control part after flowing along the heat generating body 105 opposite to the suction passage 61 with putting the partition part 112 therebetween. Consequently, fluid 30 flowing in from the suction pipe 8 and the heat generating body 105 can be mainly cooled by increasing heat radiation area by heat radiation fins, efficient cooling effect of the heat generating body 105 of the motor drive circuit part 101 can be provided and reliability of the motor drive circuit part 101 is improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to cooling of an electric motor drive circuit section of an electric compressor in which a compression mechanism section, an electric motor, and an electric motor drive circuit section are built in a main body casing.

  In this type of electric compressor, an electric motor drive circuit unit, a compression mechanism unit, and an electric motor are partitioned from each other (see, for example, Patent Document 1 or Patent Document 2). FIG. 4 is a longitudinal cross-sectional view of the electric compressor described in Patent Document 1, and a partition portion that partitions the main body casing into a compression chamber and an electric motor drive circuit portion chamber in the axial direction is provided, and the compression mechanism portion and the compression chamber are provided in the compression chamber. The electric motor is accommodated, and the electric motor drive circuit section is accommodated in the electric motor drive circuit section chamber. The motor drive circuit section faces the suction side where the motor is located through the partition section, and after cooling the motor drive circuit section and the motor with the sucked refrigerant, the typical structure in the so-called low-pressure compressor that flows into the compression section It is.

FIG. 5 is a longitudinal sectional view of an electric compressor described in Patent Document 2, in which a main body casing containing an electric motor, a compression portion, and an electric motor drive circuit portion are accommodated on the opposite side of the electric motor across the compression portion. The compressed compression mechanism portion is fastened with bolts or the like in the axial direction.
The suction refrigerant that has flowed in through the suction hole provided in the compression mechanism portion is once guided to a passage provided in the compression mechanism portion, and is sucked into the compression portion after heat exchange with the motor drive circuit. Further, the refrigerant gas compressed by the compression section is discharged from a discharge hole provided in the main body casing after cooling the electric motor. This is a typical structure in a so-called high-pressure compressor.
JP 2000-291557 A JP 2004-183631 A

  However, the structure described in Patent Document 1 is sucked into the compression unit after exchanging heat with the motor drive circuit unit and the high heat generation component of the motor by the sucked refrigerant, so that the volumetric efficiency decreases due to the rise of the sucked refrigerant temperature, It greatly affects the performance of the compressor. Furthermore, since the refrigerant discharged from the compression section is directly discharged to the outside, if the lubricating oil supplied to the compression section and accompanying the discharged refrigerant is separated to improve the performance of the refrigeration cycle, the discharge to the outside is performed. In the process, a separation device is required, which increases the size and weight of the main casing.

  On the other hand, in the structure described in Patent Document 2, the suction refrigerant is used only for cooling the motor drive circuit section, and the lubricating oil separation device is provided using the empty space of the main body casing in which the motor is accommodated. Therefore, there are great advantages in terms of performance and size of the main casing. However, in the structure described in Patent Document 2, the cooling passage is reduced because the suction passage provided in the compression mechanism portion is divided from the discharge refrigerant passage by a partition, and the heating element of the motor drive circuit portion is connected to the suction passage. The device to arrange on the back was necessary.

  An object of the present invention is to provide an electric compressor that efficiently cools an electric motor drive circuit unit without increasing the size of a main body casing, and further reduces the resistance of fluid flowing in from a suction pipe to reduce performance degradation. To do.

In order to solve the conventional problem, an electric compressor of the present invention includes a compression mechanism section, an electric motor that drives the compression mechanism section, and an electric motor drive circuit section in a main body casing, and the compression mechanism section. Comprises a compression part and a suction passage for cooling the heating element of the motor drive circuit part through the partition part, and the suction passage is along the heating element facing the fluid flowing in from the suction pipe across the partition part. And then flow to a portion opposite to other control components.

  As a result, the fluid flowing in from the suction pipe flows along the heating element with the partition portion interposed therebetween, and is efficiently cooled. Further, the heat radiation area is improved by the radiation fins, so that the heating element is generated in the motor drive circuit. Thus, an efficient cooling effect of the heating element of the motor drive circuit unit can be obtained. As a result, the reliability of the motor drive circuit section can be improved. Further, the electric compressor can be reduced in performance by reducing the resistance of the fluid flowing in from the suction pipe by devising the shape and position of the radiating fin. Furthermore, since the compression mechanism section can be configured with a minimum sealing surface and fastening bolts between the compression mechanism section and the main body casing by configuring the motor drive circuit section and the compression section through the partition section, the compressor can be downsized and Weight can be reduced.

  The electric compressor of the present invention can be directly mounted on an engine such as a hybrid vehicle due to the reduction in size and weight, and further impairs performance and reliability even under severe environments such as heating and vibration from the engine. It becomes possible to drive without.

According to a first aspect of the present invention, a main body casing includes a compression mechanism portion having a fixed scroll, a turning scroll, and a bearing, and an electric motor that drives the compression mechanism portion. A partition portion and a suction pipe are provided on the opening side of the main body casing. Airtightly comprising a sub-casing having a suction passage formed by the fixed scroll and the partition portion, and having an electric motor drive circuit portion having a heating element on a surface opposite to the suction passage of the partition portion, The suction passage is configured such that the fluid flowing in from the suction pipe flows along the heating element facing the partition portion and then flows to a portion facing the other control component. As a result of cooling, the heating element of the motor drive circuit section can be preferentially and efficiently cooled. By providing the central wall with the central wall and having a substantially U shape, the distance of the suction passage is increased, so that the heat exchange area is increased and a high cooling effect can be obtained.

  In the third aspect of the invention, particularly in the second aspect, the tip curvature of the central wall of the suction passage has a shape that roughly follows the curvature of the outer peripheral wall surface of the suction passage, thereby reducing the resistance of the suction passage and reducing performance. Can be reduced.

  In the fourth invention, particularly in the first to third inventions, by providing the fins on the partition portion facing the heating element of the suction passage, the heat radiation area is further increased, and a higher cooling effect is obtained. Can do.

  In the fifth aspect of the invention, in particular, in the fourth aspect of the invention, the fins have a shape approximately along the flow of the fluid, whereby the resistance of the suction passage is reduced, and the performance deterioration of the electric compressor can be suppressed.

  In the sixth invention, particularly in the fourth or fifth invention, the plurality of passages formed by the fins reduces the resistance of the suction passage by increasing the passage width on the outer peripheral wall surface side of the suction passage, The performance degradation of the electric compressor can be suppressed.

According to a seventh aspect of the invention, in particular, in the first to sixth aspects of the invention, by providing a bypass passage that bypasses the fluid flowing in from the suction pipe in the vicinity of the suction passage outlet, a part of the fluid is bypassed without passing through the entire suction passage. As a result, the resistance of the suction passage can be reduced and the performance degradation of the electric compressor can be suppressed.

  In the eighth invention, in particular, in the first to seventh inventions, the chamfering process is provided at the outlet portion of the suction pipe flowing into the suction passage, so that the resistance of the suction passage is reduced, and the performance of the electric compressor is reduced. Can be suppressed.

  In the ninth aspect of the invention, in particular, in the first to eighth aspects of the invention, by providing the heat insulating member on the wall surface of the suction passage, the influence from the radiant heat of the engine or the like can be prevented, and the reliability is improved.

  In the tenth aspect of the invention, in particular, in the first to ninth aspects of the invention, by providing a plurality of circular recesses on the partition portion of the suction passage, the heat radiation area is increased and the cooling effect can be improved.

  In the eleventh aspect of the invention, in particular, in the first to tenth aspects of the invention, the provision of the semicircular protrusion on the partition portion of the suction passage causes a turbulent flow of the gas refrigerant and improves the cooling effect. Can do.

  According to a twelfth aspect of the invention, in particular, in the first to eleventh aspects of the invention, the cross-sectional area of the suction passage outlet hole is 1.1 to 3.0 times the cross-sectional area of the suction pipe, so that the fluid by heat exchange in the suction passage Therefore, it is possible to reduce the resistance of the suction passage and suppress the performance deterioration of the electric compressor.

  In the thirteenth invention, in particular in the first to twelfth inventions, the partition portion is made of a material having good thermal conductivity such as an aluminum material, so that the efficiency of heat exchange from the fluid is improved and a high cooling effect is obtained. Obtainable.

  In the fourteenth aspect of the invention, in particular, in the first to thirteenth aspects of the invention, the fluid is a refrigerant mainly composed of carbon dioxide, and the refrigerant mainly composed of carbon dioxide, which has been promoted from the viewpoint of environmental protection in recent years. It is possible to respond.

  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 cross-sectional view of the electric compressor according to Embodiment 1 of the present invention. FIG. 1 shows one example in the case of a horizontal electric compressor that is installed sideways by a mounting leg 2 around a body portion of the electric compressor 1. The electric compressor 1 is inside the main casing 3. The motor 5 is built in, and the compression mechanism part 4 inserted or press-fitted into the main casing 3 is driven. The electric motor 5 is driven by an electric motor drive circuit unit 101 incorporated in the sub casing 102. Further, the main body casing 3 is provided with a liquid storage section 6 for storing a liquid used for lubrication of each sliding section including the compression mechanism section 4. The refrigerant to be handled is a gas refrigerant, and a liquid such as a lubricating oil 7 is employed as a liquid to be used for lubrication of each sliding part and a seal of the sliding part of the compression mechanism part 4. The lubricating oil 7 is compatible with the refrigerant.

The compression mechanism part 4 of the electric compressor 1 of this Embodiment is a scroll system as an example. In FIG. 1, a main bearing member 51 having a pump 13, a sub-bearing 41, an electric motor 5, and a main bearing 42 is disposed from one end wall 3 a side in the axial direction in the main body casing 3. The pump 13 is accommodated from the outer surface of the end wall portion 3a and is held between the lid body 52 and the pump body 53 which is inserted into the lid body 52. 54 is connected to the liquid storage section 6 through 54. The auxiliary bearing 41 is supported by the end wall 3a and the pump 1 of the drive shaft 14 is supported.
The side connected to 3 is pivotally supported. The electric motor 5 is configured such that the stator 5a can be rotationally driven by a rotor 5b that is fixed by shrink-fitting the stator 5a to the main casing 3 or is fixed by an annular member 17 and is fixed around the middle of the drive shaft 14. Yes. The main bearing member 51 is fixed by a fixed scroll 11 and a bolt (not shown) and is sandwiched by the sub casing 102 fitted to the opening side of the main body casing 3, and the compression mechanism portion 4 side of the drive shaft 14 is held on the main bearing. The shaft is supported by 42. Further, a scroll compressor is configured by sandwiching the orbiting scroll 12 between the main bearing member 51 and the fixed scroll 11. Between the main bearing member 51 and the orbiting scroll 12, a rotation restraining portion 57 for preventing the rotation of the orbiting scroll 12 such as an Oldham ring 57 and causing the circular movement is provided, and the drive shaft 14 is interposed via the eccentric bearing 43. The orbiting scroll 12 is connected to the orbiting scroll 12 so that the orbiting scroll 12 can be orbited on a circular path.

  In the sub-casing 102, a suction passage 61 is formed by airtightly combining a space communicating from the suction port 8 with the fixed end plate 11a of the fixed scroll 11 using a seal member 11b. The suction passage outlet hole (70 in FIG. 2) of the suction passage 61 corresponds to the suction hole in the fixed scroll 11. Further, the fixed scroll 11 is provided with a discharge hole 31 and a reed valve 31a, and is opened to a discharge chamber 63 which is constituted by a fixed end plate 11a and a lid 62 and protrudes into the suction passage 61. The discharge chamber 63 communicates with the electric motor 5 through a communication passage 64 formed between the fixed scroll 11 and the main bearing member 51 and the main casing 3.

  The motor drive circuit unit 101 includes a circuit board 103 and an electrolytic capacitor (not shown) on the opposite surface of the suction passage 61 in the partition 112 of the sub casing 102. Further, an IPM (intelligent power module) heating element 105 including a switching element having a high heat generation degree is mounted on the circuit board 103 so as to be in thermal contact with the partition portion 112. The electric motor drive circuit unit 101 is electrically connected via the compressor terminal 107 connected to the electric motor 5 by the harness connector 106, and the electric motor drive circuit unit 101 monitors the motor 5 for necessary information such as temperature. It is made to drive by. A cover 113 is provided so as to cover the motor drive circuit unit 101.

  With the above configuration, the electric motor 5 is driven by the electric motor drive circuit unit 101 to cause the compression mechanism unit 4 to move in a circular orbit via the drive shaft 14 and to drive the pump 13. At this time, the compression mechanism section 4 is provided with the return refrigerant from the refrigeration cycle in the sub-casing 102 while being supplied with the lubricating oil 7 of the liquid storage section 6 through the oil supply passage 15 of the drive shaft 14 by the pump 13 and receiving lubrication and sealing action. The air is sucked through the suction port 8, the suction passage 61 and the suction hole (not shown), compressed in the compression space 10, and discharged from the discharge hole 31 to the discharge chamber 63. The refrigerant discharged into the discharge chamber 63 enters the electric motor 5 side through the communication passage 64 and is discharged from the discharge port 9 of the main casing 3 while cooling the electric motor 5. In the process up to the discharge port 9, the refrigerant 30 is subjected to various gas-liquid separations such as collision, centrifugation, throttling, and the like, and is subjected to separation of the lubricating oil 7. Also lubricate.

  Next, a configuration for effectively cooling the heating element 105 of the electric motor drive circuit unit 101 in the suction passage 61 of the sub casing 102 will be described. FIG. 2 is a perspective view of the suction passage of the electric compressor according to the first embodiment of the present invention, showing a state in which the sub casing and the fixed scroll are disassembled. In addition, the discharge chamber 63 formed in the fixed scroll 11 is assembled so as to fit into the recess 63 a of the sub casing 102, and the suction passage 61 is formed.

The suction passage 61 is provided with a central wall 71 and is formed in a U-shape as indicated by an arrow A from the suction port 8 to the suction passage outlet hole 70. In the figure, the portion that becomes the bottom surface of the suction passage 61 is a partition portion 112 having the motor drive circuit portion 101 on the back surface, and in particular, the portion immediately after flowing in from the suction pipe 8 extends along the heating element 105 with the partition portion 112 interposed therebetween. In addition, fins 72 are formed in a portion facing the heating element 105 to improve heat exchange efficiency. The fins 72 are formed along the flow of the refrigerant 30, and the U-shaped curved portion has a shape that substantially follows the curvature of the outer peripheral wall surface 73 of the suction passage 61. Further, the plurality of passages formed by the fins 72 have a passage width (a <b <c) on the outer peripheral wall surface 73 side increased. Further, two hemispherical protrusions 74 are formed on the front and rear sides of the fin 72 to form a screw for fixing the heating element 105 on the back surface. Further, a chamfer 8 a is provided at the outlet portion of the suction pipe 8 that flows into the suction passage 61.

  In the configuration described above, the refrigerant 30 that has flowed from the suction port 8 flows through the U-shaped suction passage 61. The low-temperature refrigerant 30 first flows along the opposing heating element 105 with the partition portion 112 interposed therebetween, thereby effectively exchanging heat with the heating element 105 and cooling. After that, it also flows to the part facing the other control components, cools the entire motor drive circuit unit 101, and flows into the compression space 10 from the suction passage outlet hole 70 of the fixed end plate 11a.

  Thus, the suction passage 61 is formed in a substantially U shape along the fins 72, so that the fluid flowing in from the suction pipe 8 flows into the compression space 10 through the suction passage outlet hole 70 of the fixed end plate 11a. The distance until this is increased and the heat exchange area is increased, so that the heating element 105 can be cooled effectively. In addition, the suction passage 61 has a larger heat exchange area due to the fins 72 being configured, so that the heating element 105 can be cooled more efficiently.

  Moreover, the fin 72 reduces the resistance of the suction passage 61 due to the shape approximately along the flow of the fluid, and can suppress the performance degradation of the electric compressor. Further, by forming the plurality of passages formed by the fins 72 so that the passage width on the outer peripheral wall surface 73 side is increased, the resistance of the suction passage 61 is reduced, and the performance deterioration of the electric compressor can be suppressed. . Further, by providing the chamfer 8a at the outlet portion of the suction pipe 8 that flows into the suction passage 61, the resistance of the suction passage 61 is reduced, and the performance deterioration of the electric compressor can be suppressed. Furthermore, by providing the semicircular projections 74 before and after the fins 72, a turbulent flow of the gas refrigerant occurs, and a higher cooling effect can be obtained.

(Embodiment 2)
FIG. 3 is a front view of a sub casing of the electric compressor according to the second embodiment of the present invention. In FIG. 3, in addition to the fins 72, the suction passage 61 is formed with a large number of circular recesses 75 in the partition 112. In addition, the curvature of the tip of the central wall 71 is set to a shape that roughly follows the curvature of the outer peripheral wall surface 73 of the suction passage 61, and a heat insulating member 76 is provided on the entire side wall surface of the suction passage 61 including the central wall 71 and the outer peripheral wall surface 73. Yes. Further, a bypass passage 77 is formed on the rear end side of the central wall 71 to bypass the refrigerant 30 flowing from the suction pipe 8 in the vicinity of the suction passage outlet hole 70 serving as the outlet of the suction passage 61. The bypass passage 77 has the same form as that shown in FIG.

  With the above configuration, the refrigerant 30 in the suction passage 61 generates a turbulent flow in the concave portion 75 in addition to the fins 71 and promotes heat exchange. A smooth flow is guided at the tip of the central wall 71. Further, in the bypass passage 77, a part of the refrigerant 30 reaches the suction passage outlet hole 70 without passing through the suction passage 61.

In this way, by bypassing the refrigerant 30 flowing in from the suction pipe 8 by the bypass passage 77, the resistance of the suction passage 61 can be reduced, and the performance deterioration of the electric compressor can be suppressed. Moreover, by making the front-end | tip part of the center wall 71 into the curved surface along the outer peripheral wall surface 73, the resistance of the suction passage 61 can be reduced and the performance fall of an electric compressor can be suppressed. Furthermore, by providing the heat insulating member 120 on the side wall surface of the suction passage 61, it is possible to prevent the influence of radiant heat from the engine or the like and to improve the reliability.

  In the above embodiment, if the cross-sectional area of the suction passage outlet hole 70 is 1.1 to 3.0 times the cross-sectional area of the suction pipe 8, the amount of expansion of the fluid due to heat exchange in the suction passage 61 is sucked. The passage outlet hole 70 will not be throttled, the resistance of the suction passage 61 can be reduced, and the performance deterioration of the electric compressor can be suppressed.

  Further, in the electric compressor according to the present invention, the sub casing 102 is made of a material having a good thermal conductivity such as an aluminum material, so that the efficiency of heat exchange from the refrigerant 30 is improved and a high cooling effect is obtained. This is preferable. Furthermore, it is possible to cope with a refrigerant mainly composed of carbon dioxide, which has been promoted from the viewpoint of environmental protection in recent years, and is suitable for improving the efficiency and reliability of the present invention and reducing the size and weight.

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

Sectional drawing of the electric compressor in Embodiment 1 of this invention The perspective view of the subcasing of the electric compressor in Embodiment 1 of this invention The perspective view of the subcasing of the electric compressor in Embodiment 2 of this invention Cross section of a conventional electric compressor Cross section of a conventional electric compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric compressor 3 Main body casing 4 Compression mechanism part 5 Electric motor 8 Suction pipe 8a Chamfer 11 Fixed scroll 11a Fixed end plate 12 Orbiting scroll 30 Refrigerant 61 Intake passage 62 Cover body 63 Discharge chamber 64 Connection passage 70 Intake passage outlet hole 71 Central wall 72 Fin 73 Outer peripheral wall surface 74 Projection part 75 Concave part 76 Heat insulation member 77 Bypass passage 101 Electric motor drive circuit part 102 Sub casing 105 Heating element 112 Partition part

Claims (14)

A sub casing having a compression mechanism portion having a fixed scroll, a turning scroll, and a bearing, and an electric motor for driving the compression mechanism portion, and having a partition portion and a suction pipe on the opening side of the main body casing. A suction passage is formed by the fixed scroll and the partition portion in an airtight manner, and includes an electric motor drive circuit portion having a heating element on a surface opposite to the suction passage of the partition portion, and the suction passage includes the suction passage. The fluid flowing in from the pipe flows along the heating elements facing each other across the partition portion, and then flows to a portion facing the other control components to cool the motor drive circuit portion. An electric compressor characterized by that. The electric compressor according to claim 1, wherein the suction passage is provided with a central wall and is substantially U-shaped. 3. The electric compressor according to claim 2, wherein the curvature of the front end portion of the central wall of the suction passage has a shape that substantially matches the curvature of the outer peripheral wall surface of the suction passage. The electric compressor according to any one of claims 1 to 3, wherein the suction passage is provided with fins on a partition portion facing the heating element. The electric compressor according to claim 4, wherein the fin has a shape approximately along the flow of the fluid. 6. The electric compressor according to claim 4, wherein the plurality of passages formed by the fins have a large passage width on the outer peripheral wall surface side of the suction passage. The electric compressor according to any one of claims 1 to 6, further comprising a bypass passage that bypasses the fluid flowing in from the suction pipe in the vicinity of the suction passage outlet. The electric compressor according to any one of claims 1 to 7, wherein a chamfering process is provided at an outlet portion of the suction pipe flowing into the suction passage. The electric compressor according to any one of claims 1 to 8, wherein a heat insulating member is provided on a side wall surface of the suction passage. The electric compressor according to any one of claims 1 to 9, wherein a plurality of recesses are provided on a partition portion of the suction passage. 11. The electric compressor according to claim 1, wherein a hemispherical protrusion is provided on a partition portion of the suction passage. The electric compressor according to any one of claims 1 to 11, wherein a cross-sectional area of the suction passage outlet hole is 1.1 to 3.0 times a cross-sectional area of the suction pipe. The electric compressor according to any one of claims 1 to 12, wherein the partition portion is configured using a material having good thermal conductivity such as an aluminum material. The electric compressor according to any one of claims 1 to 13, wherein the fluid flowing in from the suction pipe uses a refrigerant mainly composed of carbon dioxide.