JP2012057504A - Electric compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric compressor that effectively cools an electric-motor drive circuit without increasing cost and the size of a body casing.SOLUTION: The electric compressor includes an intake passage 61, in which a coolant for cooling the electric-motor drive circuit flows, at a part corresponding to the electric-motor drive circuit 101. One or more level differences 114 is provided at a portion being an inlet into the intake passage 61, and the level difference 114 is provided at a position where the level difference faces a part of the electric-motor drive circuit 101. Naturally, the electric-motor drive circuit 101 also effectively cools a heating element mounted on the circuit, and thereby the electric-motor drive circuit can be constituted of low-cost electric parts and the compact and low-cost electric compressor can be provided.

Description

  The present invention relates to an electric compressor having a motor casing circuit in a main body casing in addition to a compression mechanism and an electric motor.

  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). The electric compressor described in Patent Literature 1 is provided with a partition portion that partitions the main body casing into a compression chamber and a motor drive circuit portion chamber in the axial direction, and the compression mechanism portion and the motor are accommodated in the compression chamber, and the motor drive circuit portion chamber is provided. The motor drive circuit section is housed in The motor drive circuit section faces the suction side where the motor is located through the partition section, and is configured to flow into the compression section after cooling the motor drive circuit section and the motor with the sucked refrigerant, which is a typical low pressure compressor. It has a typical structure.

  Further, the one described in Patent Document 2 is configured by fastening a circuit case containing an electric motor drive circuit portion with a bolt or the like to an end portion in an axial direction of a main body casing incorporating an electric motor and a compressor with the compression portion interposed therebetween. It is. This type of electric compressor is also provided in the main casing after the motor drive circuit is cooled by the refrigerant sucked from the suction hole provided in the circuit case and then sucked into the compressor in the main casing and the motor is cooled. It is configured to be discharged from the discharged discharge hole, and has a typical structure in a so-called high-pressure compressor.

JP 2000-291557 A JP 2004-183631 A

  In any of the above-described electric compressors, the motor drive circuit unit is cooled by the suction refrigerant, and therefore, a device has been devised such as providing fins on the surface for cooling the motor drive circuit in order to increase the cooling effect. However, even if such fins are provided, sufficient cooling performance is still not obtained, and it is necessary to increase the heat resistance of the motor drive circuit, and there is a problem that expensive electronic components are required and expensive. It was. In particular, the electric drive circuit section is equipped with a heat generating component that generates high heat, such as an IPM (intelligent power module), and effective cooling is required. This is because in a high-pressure compressor as described in Patent Document 2, high-temperature and high-pressure gas after compression flows in the main body casing and is at a high temperature, and therefore heat conduction from the main body casing to the circuit case. However, the cooling effect by the suction refrigerant has been offset, and improvement of the cooling performance of the motor drive circuit has been a major issue.

  An object of the present invention is to solve the above-described conventional problems, and to provide an electric compressor that can efficiently cool an electric motor drive circuit unit without increasing costs and enlarging a main body casing.

In order to solve the above-described conventional problems, an electric compressor of the present invention includes a main body casing including a compression mechanism portion and an electric motor for driving the compression mechanism portion, and a sub-casing attached to the main body casing and an electric motor drive circuit portion. And a suction passage that serves as an inlet to the suction passage and a suction passage that includes a suction passage through which a refrigerant that cools the motor drive circuit portion flows in a portion corresponding to the motor drive circuit portion. One or a plurality of step portions where the refrigerant collides with each other are provided, and the step portions are provided at positions facing a part of the motor drive circuit portion.

  With the above configuration, the refrigerant from the outside (refrigeration cycle) flows from the suction port via the step portion through the suction passage, and cools the motor drive circuit portion with the refrigerant flowing through the suction passage. Since the compatible lubricating oil has a large inertial force, it collides with the stepped portion. At that time, the refrigerant dissolved in the lubricating oil evaporates, and the stepped portion is efficiently cooled by the latent heat of evaporation. Since a part of the electric motor drive circuit unit is opposed to the stepped portion, the electric motor drive circuit unit can be efficiently cooled by both the cooling action of the refrigerant itself and the latent heat of vaporization. Thereby, the reliability of the motor drive circuit unit can be improved without greatly changing the shape of the main body casing and causing an increase in size.

  Since the electric compressor of the present invention can improve the cooling performance of the electric motor drive circuit unit, the electric drive circuit unit can be configured with inexpensive electronic components, and a small and inexpensive electric compressor can be provided. It can be directly mounted on an engine such as a hybrid vehicle. Furthermore, it is possible to operate without impairing performance and reliability even under severe environments such as heating and vibration from the engine.

Sectional drawing of the electric compressor in Embodiment 1 of this invention The exploded perspective view of the sub casing of the electric compressor in Embodiment 1 Sectional drawing of the partition part of the electric compressor in the same Embodiment 1 (BB arrow line view of FIG. 2)

  1st invention is equipped with the main body casing which incorporated the compression mechanism part and the electric motor which drives this, and the subcasing which attached to the said main body casing and attached the electric motor drive circuit part, and respond | corresponds with the said electric motor drive circuit part An electric compressor having a suction passage through which a refrigerant for cooling the motor drive circuit portion flows, wherein the refrigerant collides with the suction passage between the suction passage serving as an inlet to the suction passage and the suction passage. One or a plurality of step portions are provided, and this step portion is provided at a position facing a part of the motor drive circuit portion, so that the motor drive circuit portion can be efficiently cooled and is inexpensive. An electric drive circuit unit can be configured with simple electronic components, and a small and inexpensive electric compressor can be provided.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, the compression mechanism section includes a fixed scroll and a turning scroll, and a sub casing is attached to the end side of the main casing provided with the compression mechanism section. The sub casing has a partition portion and a suction port, and is attached to the main body casing to form a suction passage between the fixed scroll and the partition portion, and the surface of the partition portion opposite to the suction passage. An electric motor drive circuit portion having a heating element is provided in the electric drive circuit, and a part of the electric drive circuit is positioned to face the step portion. Thereby, like the first invention, the electric motor drive circuit section and the heating element mounted on the circuit can be efficiently cooled.

  According to a third aspect of the invention, particularly in the first or second aspect, a cooling fin is provided in the suction passage, and the refrigerant flowing from the suction port collides with the cooling fin after colliding with a stepped portion between the suction port and the suction passage. In this cooling fan, the cooling action by the latent heat of vaporization is added and the motor drive circuit section can be efficiently cooled.

  In the fourth invention, in particular, in the first to third inventions, the partition portion is made of a material having good thermal conductivity such as an aluminum material, and heat exchange efficiency with the refrigerant flowing through the suction passage is improved. High cooling effect can be obtained.

  The fifth aspect of the invention is a construction using a low GWD refrigerant as the refrigerant in the first to fourth aspects of the invention, and is also a refrigerant mainly composed of carbon dioxide 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 sectional view of an electric compressor according to an embodiment of the present invention. FIG. 1 shows an example of a horizontal electric compressor that is installed sideways by mounting legs 2 around the body of the electric compressor 1.

  The electric compressor 1 has a built-in electric motor 5 in the main body casing 3, and drives the compression mechanism 4 that is fitted or press-fitted into the main body casing 3. 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 lubricating 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 unit 6 through 54. The auxiliary bearing 41 is supported by the end wall 3a and pivotally supports the side of the drive shaft 14 connected to the pump 13.

  The electric motor 5 is configured such that the stator 5a is shrink-fitted and fixed to the main body casing 3 or is fixed by the annular member 17, and the drive shaft 14 can be rotationally driven by the rotor 5b fixed around the drive shaft 14. . The main bearing member 51 is fixed by a fixed scroll 11 and a bolt (not shown) or the like, and is sandwiched by the sub casing 102 located on the opening side of the main body casing 3, and the compression mechanism portion 4 side of the drive shaft 14 is held by the main bearing 42. It is pivotally supported. 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 such as an Oldham ring for preventing the orbiting scroll 12 from rotating and providing a circular motion is provided, and the drive shaft 14 orbits via the eccentric bearing 43. It is connected to the scroll 12 so that the orbiting scroll 12 can be turned on a circular path.

The sub casing 102 is fitted and fixed to the opening side of the main casing 3, and forms a suction passage 61 by being hermetically combined with the fixed end plate 11 a of the fixed scroll 11 using a seal member 11 b in a space communicating from the suction port 8. ing. 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. Here, since the discharge chamber 63 is formed so as to protrude into the suction passage 61, that is, overlap the discharge chamber 63, the discharge chamber 63 is formed in comparison with the case where the discharge chamber 63 and the suction passage 61 are separately formed and superposed. The axial dimension can be reduced by the amount of protrusion.

  The electric motor drive circuit unit 101 is attached to the partition 112 of the sub casing 102 and includes a circuit board 103 and an electrolytic capacitor (not shown) on the opposite surface of the suction passage 61. 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 a compressor terminal 107 connected to the electric motor 5 by a harness connector 106, and the electric motor drive circuit unit 101 monitors the motor 5 for necessary information such as temperature. To be driven 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 and drives the compression mechanism unit 4 and the pump 13 via the drive shaft 14. 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 motor drive circuit unit 101 and the heating element 105 in the suction passage 61 of the sub casing 102 will be described. FIG. 2 is an exploded perspective view of the suction passage of the electric compressor in the embodiment of the present invention, and shows a state in which the sub casing 102 and the fixed scroll 11 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 so that the refrigerant flows from the suction port 8 to the suction passage outlet hole 70 as indicated by an arrow A. In the drawing, 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 refrigerant immediately after flowing in from the suction port 8 sandwiches the partition portion 112 and the motor drive circuit portion 101 and A step portion 114 is formed between the suction port 8 and the suction passage 61 as shown in FIG. 3 and flows to the suction passage 61 via the step portion 114. It is configured to flow. In addition, a plurality of cooling fins 72 are integrally formed from the partition portion 112 in the suction passage portion facing the motor drive circuit portion 101 and the heating element 105, and in particular, a bent portion is provided in the portion of the cooling fin 72 facing the heating element 105. 72a is provided.

The cooling operation in the above configuration will be described below. The lubricating oil including the low-temperature refrigerant 30 flowing from the suction port 8 flows through the suction passage 61 via the stepped portion 114 of the suction port 8. The lubricating oil including the refrigerant 30 flowing through the stepped portion 114 and the suction passage 61 cools the partition portion 112 as in the conventional case, but further exhibits the following cooling action. That is, the lubricating oil containing the refrigerant 30 first collides with the stepped portion 114, the refrigerant in the lubricating oil evaporates, further cools the partition portion 112 by the latent heat of evaporation, and the motor drive circuit attached to the partition portion 112. Part 101 is cooled in cooperation. Further, the refrigerant flowing into the suction passage 61 via the stepped portion 114 collides with the bent portion 72a of the cooling fin 72, and similarly, the refrigerant in the lubricating oil evaporates, and is mounted on the motor drive circuit portion 101 in particular. The heating element 105 is cooled in cooperation. And this refrigerant 3
The lubricating oil containing 0 flows into the compression space 10 from the suction passage outlet hole 70 of the fixed end plate 11a.

  In this way, not only the motor drive circuit unit 101 but also the heating element 105 mounted thereon is effectively cooled. Therefore, the electric drive circuit unit can be configured with inexpensive electronic components, and the electric compressor can be made small and inexpensive. This high cooling effect can be achieved with a configuration in which the stepped portion 114 and the bent portion 72a are provided in a portion facing a part of the conventional motor drive circuit portion 101, and a special effect for increasing the cooling effect. There is no need to add a new configuration, and the electric compressor can be made small and inexpensive.

  In addition, since this electric compressor is constructed by using a material having good thermal conductivity such as an aluminum material, the efficiency of heat exchange with the refrigerant 30 can be improved and a high cooling effect can be obtained. Is preferable. Furthermore, it is possible to cope with low GWP refrigerants such as a refrigerant mainly composed of carbon dioxide, which has been promoted from the viewpoint of environmental protection in recent years. In the improvement of efficiency and reliability of the present invention, and reduction in size and weight. Is preferred.

  As described above, the electric compressor according to the present invention can efficiently cool the electric motor drive circuit unit with a simple configuration, can employ inexpensive electronic components, can reduce costs, and also has the reliability of the electric drive circuit unit. In addition, the size and weight can be reduced. As a result, it can be mounted on an engine and can be widely applied to environmental vehicles such as hybrid vehicles.

DESCRIPTION OF SYMBOLS 1 Electric compressor 3 Main body casing 4 Compression mechanism part 5 Electric motor 8 Suction port 11 Fixed scroll 11a Fixed end plate 12 Orbiting scroll 30 Refrigerant 61 Suction passage 62 Lid 63 Discharge chamber 64 Connection passage 70 Suction passage outlet hole 71 Central wall 72 Cooling fin 72a Bent part 101 Electric motor drive circuit part 102 Subcasing 105 Heating element 112 Partition part 114 Step part

Claims (5)

A main body casing including a compression mechanism section and an electric motor that drives the compression mechanism section; and a sub casing that is attached to the main body casing and has an electric motor driving circuit section attached thereto; and the electric motor driving circuit corresponding to the electric motor driving circuit section An electric compressor having a suction passage through which a refrigerant for cooling the section flows, wherein one or a plurality of step portions where the refrigerant collides between the suction passage serving as an inlet to the suction passage and the suction passage. Electric compressor provided. The compression mechanism section includes a fixed scroll and a turning scroll, and a sub casing is attached to an end side of the main casing provided with the compression mechanism section. The sub casing includes a partition section and a suction pipe. A suction passage is formed between the fixed scroll and the partition portion by being attached to the main body casing, and an electric motor drive circuit portion having a heating element is provided on a surface opposite to the suction passage of the partition portion. The electric compressor according to claim 1, wherein a part of the electric drive circuit is positioned to face the stepped portion. The cooling fin is provided in the suction passage, and the refrigerant flowing in from the suction port collides with the stepped portion between the suction port and the suction passage and then collides with the cooling fin. Or the electric compressor of 2. The electric compressor according to any one of claims 1 to 3, 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 4, wherein a low GWP refrigerant is used as the refrigerant.