JP5194766B2 - Inverter-integrated electric compressor - Google Patents

Description

  The present invention relates to an electric compressor in which a compression mechanism portion that sucks, compresses and discharges fluid and an electric motor that drives the compression mechanism portion are built in a fuselage container, and the electric motor is driven by an inverter.

  In this type of electric compressor, an inverter, a compression mechanism unit, and an electric motor are partitioned from each other (see, for example, Patent Document 1). As shown in FIG. 5, the one described in Patent Document 1 is provided with a partition wall that partitions an airframe container into a compression chamber and an inverter chamber in the axial direction. The compression chamber and the electric motor are accommodated in the compression chamber, and the inverter chamber Contains an inverter. Here, the inverter has a typical structure in a so-called low-pressure compressor that faces the suction side of the electric motor through the partition wall and cools the inverter and the electric motor with the suction refrigerant and then flows into the compression mechanism. . Further, as shown in FIG. 6, the device described in Patent Document 2 includes an airframe container that houses an electric motor, a compression mechanism section, and an inverter case that houses an inverter on the opposite side of the electric motor across the compression mechanism section in the axial direction. It is fastened with bolts.

The suction refrigerant flowing in from the suction hole provided in the compression mechanism is once guided to a passage provided in the inverter case, and after returning heat to the inverter, is returned to the compression mechanism. Further, the refrigerant gas compressed by the compression mechanism portion is discharged from a discharge hole provided in the fuselage container 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, 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 Greatly impacts performance. Furthermore, since the refrigerant discharged from the compression mechanism is directly discharged to the outside without reaching the motor side, the lubricating oil supplied to the compression mechanism and accompanying the discharged refrigerant should be separated to improve the performance of the refrigeration cycle. Then, it is difficult to separate because it is only performed in the discharge process to the outside. 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, the structure described in Patent Document 2 is different from the structure described in Patent Document 1 in that the suction refrigerant is used only for inverter cooling, and the lubricating oil separator is an empty body container in which the electric motor is accommodated. Since the space can be provided, there are great advantages in terms of performance and the size of the aircraft container.

  However, in the structure described in Patent Document 2, the suction refrigerant passage provided in the inverter case is close to the discharge refrigerant passage with a partition wall, and the inverter case is a fuselage container and a seal portion containing a compression part or an electric motor as a heating element. Since the inverter case is heated by heat conduction, it is necessary to devise a structure that makes it difficult for heat to enter the inverter case together with efficient cooling means. In addition, since this compressor is often installed in the vicinity of the engine, it also has a problem of preventing radiant heat from entering the inverter case and the inverter cover. Further, since the container and the inverter case incorporating the compression section and the electric motor have a laminated structure, there are problems in the number of bolts and seals for assembly adjustment, shaft centering, and fastening.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an inverter-integrated electric compressor structure that can significantly reduce costs, and to prevent heat from entering the inverter case and inverter cover in order to efficiently cool the inverter. Is to provide a machine.

  In order to solve the above-described conventional problems, an electric compressor according to the present invention includes a compression mechanism that performs suction, compression, and discharge of fluid, a main body casing that includes an electric motor that drives the compression mechanism, and the electric motor. An inverter case containing a drive inverter and an inverter cover for sealing the inverter case are provided, the compression mechanism is accommodated in the main body casing, and is sandwiched between an inner peripheral end surface of the inverter case and an inner surface stepped portion of the main body casing. And is sealed using a sealing material between the end face of the main body casing and the outer peripheral end face of the inverter case, and between the inner peripheral end face of the inverter case and the end face of the compression mechanism portion. An inlet that cools the back of the inverter's installation wall by providing a refrigerant suction passage in a sealed space that is configured with a sealing material. It is over data-integrated electric compressor. Next, the seal material is provided with a seal groove provided on either one of the opposing end faces, leaving a maximum portion between the inner peripheral end face of the inverter case and the end face of the compression mechanism, and the inverter case end face and the fuselage container. By providing a gap within the elastic range of the sealing material over the entire circumference, the heat conduction to the inverter case is suppressed.

  Further, in the second embodiment, the sealing material is a plate-shaped sealing material having a protrusion that allows elastic deformation and having a lower thermal conductivity than the material forming the inverter case, and the inner peripheral end surface and the outer peripheral end surface of the inverter case Are formed on the same plane, and the sealing material at the two locations of the inner periphery and the outer periphery is integrally formed as an inverter-integrated electric compressor.

  Furthermore, the inverter case and the inverter cover are made of an aluminum alloy, and the surface is subjected to alumite treatment to suppress heat intrusion due to heat radiation from the external environment.

  As a result, the motor and the compression mechanism unit are accommodated in the same machine body container, so that the shaft center shift can be prevented without performing special shaft center adjustment. By sandwiching and fixing in a hermetically sealed state, the compressor can be configured with a minimum sealing surface and fastening bolts, so that the compressor can be reduced in size and weight.

  In addition, the inverter case seal structure has been devised to reduce heat ingress from the external environment by heat conduction from the fuselage container and compression section and anodizing treatment of the inverter cover, etc. It can be carried out.

  The inverter-integrated 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, performance and reliability can be obtained even under severe environments such as heating and vibration from the engine. It becomes possible to drive without impairing the performance.

  A first aspect of the present invention is a compression mechanism portion that performs suction, compression, and discharge of fluid, a main body casing that includes an electric motor that drives the compression mechanism portion, an inverter case that includes an inverter that drives the electric motor, and the inverter case An inverter cover that hermetically seals, the compression mechanism portion is accommodated in the main body casing, and is sandwiched and fixed by an inner peripheral end surface of the inverter case and an inner surface stepped portion of the main body casing, and the end surface of the main body casing and the It is a structure that is sealed using a sealing material between the outer peripheral end surfaces of the inverter case, and a sealed space that is configured by installing a sealing material between the inner peripheral end surface of the inverter case and the end surface of the compression mechanism section. By providing an inverter-integrated electric compressor that cools the back surface of the inverter installation wall by providing a refrigerant suction passage, By accommodating the motive and the compression mechanism in the same machine body container, it is possible to prevent misalignment of the shaft without performing special shaft center adjustment, and to reduce the number of parts of the sealing material and fastening bolt. .

  In the second aspect of the invention, in particular, the sealing material of the first aspect of the invention is provided with a seal groove provided on one of the opposing end faces, and a maximum portion is provided between the inner peripheral end face of the inverter case and the end face of the compression mechanism portion. The gap between the end face of the inverter case and the end face of the main body casing is provided within the elastic range of the sealing material over the entire circumference, thereby suppressing heat conduction to the inverter case. The cooling effect is improved.

  According to a third aspect of the invention, in particular, the plate-shaped sealing material of the second aspect of the invention comprises a protrusion having an elastic deformation and a material having a lower thermal conductivity than the material forming the inverter case, and the inverter case The inner peripheral end surface and the outer peripheral end surface are formed on the same plane, and the sealing material at the two locations of the inner periphery and the outer periphery is integrally molded, so that the processing cost can be reduced and the use of a low heat conductive material can be applied to the inverter case. Heat conduction can be suppressed.

  In the fourth aspect of the invention, the inverter case and the inverter cover are made of an aluminum alloy, and the surface is subjected to alumite treatment, so that heat entry due to heat radiation from the external environment can be suppressed, so that the cooling efficiency of the inverter is greatly 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)
1 is a longitudinal sectional view of an inverter-integrated electric compressor according to Embodiment 1 of the present invention. 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 5 is housed inside, and the compression mechanism 4 that is inserted into or pressed into the main casing 3 is driven. The electric motor 5 is driven by a motor drive circuit unit 101 incorporated in the inverter case 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. However, the present invention is not limited to these. Basically, a compression mechanism unit 4 that sucks, compresses and discharges liquid, a main body casing 3 that houses an electric motor 5 that drives the compression mechanism unit 4, and a motor drive circuit unit 101 that drives the electric motor 5 are incorporated. The following description does not limit the description of the scope of the claims.

  The compression mechanism section 4 of the electric compressor 1 according to the present embodiment is of a scroll type as an example. As shown in FIG. 1, the fixed end plate 11a and the fixed spiral section 11 whose blades rise from the revolving end plate 12a, The compression space 10 formed by meshing with the swirling spiral portion 12 changes its volume with movement when the swirling spiral portion 12 is circularly orbitally moved with respect to the fixed spiral portion 11 via the drive shaft 14 by the electric motor 5. Thus, the refrigerant 30 returning from the external cycle is sucked, compressed and discharged to the external cycle through the suction port 8 provided in the inverter case 102 and the discharge port 9 provided in the main body casing 3.

  At the same time, the lubricating oil 7 stored in the liquid storage part 6 of the main body casing 3 is driven by driving the positive displacement pump 13 or the like by the drive shaft 14 or using the differential pressure in the main body casing 3. As the swirl spiral portion 12 is driven to rotate through the oil supply passage 15 of the shaft 14, the liquid is supplied to the liquid reservoir 21 and the liquid reservoir 22 on the back surface of the swirl spiral portion 12. A portion of the lubricating oil 7 is supplied to the back side of the outer peripheral portion of the swirl swirl 12 through the swirl swirl 12 to a predetermined restriction base such as a throttle 23 to back up the swirl swirl 12, The swirl spiral part 12 is supplied to a holding groove 25 that holds a tip seal 24 that is an example of a seal member between the blades of the swirl spiral part 12 and the fixed spiral part 11 at the tip of the swirl spiral part 12, and fixed and swirl each spiral part 11, 12 Seal between Reduce the fine lubrication. Further, another part of the lubricating oil 7 supplied to the liquid reservoir 21 lubricates the bearings 42 and 43 through the eccentric bearing 43, the liquid reservoir 22, and the main bearing 42, and then flows out to the electric motor 5 side. It is collected into the liquid storage unit 6.

  Further, a main bearing member 51 having a pump 13, a sub-bearing 41, an electric motor 5, and a main bearing 42 is arranged 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 side connected to the pump 13 of the drive shaft 14 is 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 to the fixed spiral portion 11 with a bolt (not shown) or the like, fitted into the opening end of the main body casing 3, and clamped by the inverter case 102 so that the compression mechanism portion 4 side of the drive shaft 14 is held. The main bearing 42 is used for bearing. Further, a scroll compressor is configured by sandwiching the swirl spiral portion 12 between the main bearing member 51 and the fixed spiral portion 11. Between the main bearing member 51 and the swirl spiral portion 12, a rotation restraint portion 57 for preventing the swirl spiral portion 12 such as an Oldham ring 57 from rotating and causing a circular motion is provided, and the drive shaft 14 is connected to the eccentric bearing 43. The swirl spiral part 12 is connected to the swirl spiral part 12 through the circular orbit.

  The compression mechanism section 4 is provided with a discharge hole 31 and a reed valve 31a, and is opened to a discharge chamber 62 composed of a fixed end plate 11a and a lid 65. The discharge chamber 62 is an electric motor having a discharge hole 9 between the compression mechanism portion 4 and the end wall 3a through the fixed spiral portion 11 and the main bearing member 51 or a communication passage 63 formed between them and the main body casing 3. It leads to the 5th side.

  The motor drive circuit unit 101 is configured by accommodating a circuit board 103 and an electrolytic capacitor (not shown) on the opposite side of the suction chamber 61 and the discharge chamber 62 with an end wall 102 a in the inverter case 102. Is mounted with an IPM (intelligent power module) 105 including a switching element having a high heat generation degree. The motor drive circuit unit 101 is electrically connected to the electric motor 5 or the like via a compressor terminal 106 connected by a harness connector 107, and the motor drive circuit unit 101 monitors the motor 5 for necessary information such as temperature. 101 is driven. For this reason, the motor drive circuit unit 101 is provided with a harness connector (not shown) for electrical connection with the outside.

  As described above, the electric motor 5 is driven by the motor drive circuit unit 101 to move the compression mechanism unit 4 in a circular orbit via the drive shaft 14 and to drive the pump 13. At this time, the compression mechanism section 4 is supplied with the lubricating oil 7 of the liquid storage section 6 by the pump 13 and receives the lubricating and sealing action, and sucks the return refrigerant from the refrigeration cycle through the suction port 8 provided in the inverter case 102. , Compressed and discharged from the discharge port 31 to the discharge chamber 62. The refrigerant discharged into the discharge chamber 62 enters the electric motor 5 side through the communication passage 63, and in the long process until the electric motor 5 is cooled and discharged from the discharge port 9 of the main body casing 3, the refrigerant collides, centrifuges, throttles, etc. The sub-bearing 41 is also lubricated by the accompanying partial lubricating oil 7 while various types of gas-liquid separation is performed and the lubricating oil 7 is separated.

  In the electric compressor 1 having the above configuration, a cooling passage structure in the inverter case 102 will be described with reference to FIG. FIG. 2 is an exploded view of the cooling passage space constituted by the inverter case 102 and the fixed end plate 11a. The refrigerant sucked from the suction port 8 provided in the inverter case 102 is diffused into the suction passage space 70, cools the end wall 102a, and exchanges heat with a heating element such as the IPM 105 mounted on the back surface. After that, it flows into the compression space 10 through the passage hole 71 of the fixed end plate 11a.

  In addition, the compressor terminal 106 is fixed to the inverter case 102 by a tome 80 or the like. The lead wire 81 from the electric motor 5 is connected to the harness connector 107 through a communication passage 82 provided in the vicinity of the outer periphery of the fixed end plate 11a, and is inserted and fixed to the compressor terminal 106.

  Further, the cooling effect can be further enhanced by providing guide fins 75 for controlling the flow of the refrigerant on the end wall 102a of the inverter case 102 at positions facing the heating elements mounted on the back surface.

  Returning again to FIG. Further, by fixing the inverter cover 113 to the inverter case 102 with a screw or the like, the motor drive circuit unit 101 can be protected from external effects. Furthermore, an anodized surface treatment layer 114 is formed on the outer walls of the inverter case 102 and the inverter cover 113 to prevent heat from entering the inverter case 102 when the engine room becomes hot or the engine room becomes hot, and reflects the radiant heat. To prevent heat conduction.

  Next, a seal groove is provided on the end surface 3a of the main casing 3 and an O-ring 3b is provided. In addition, an O-ring groove 11b and an O-ring 11c are provided on the end surface 11a on the inverter case 102 side of the fixed spiral portion 11 constituting the compression portion in order to form the suction passage space 70. The former is closed by the outer peripheral end face of the inverter case 102, and the latter is closed by the inner peripheral end face of the inverter case 102. Here, on the inner peripheral end face of the inverter case 102, a surface within the elastic range of the O-ring 11c is used to reduce the heat conduction area from the fixed spiral part 11 to the inverter case 102 as much as possible except for the face for pressing the compression part 4. A gap 11d is provided.

  On the other hand, when the inverter case 102 is bolted to the main casing 3 between the outer peripheral end face of the inverter case 102 and the end face of the main casing 3, there is a minute gap 3 c within the elastic range of the O-ring 3 b over the entire circumference. The heat conduction from the main casing 3 to the inverter case 102 is set to be suppressed (see FIG. 3).

(Embodiment 2)
A second embodiment relating to a seal structure between the inverter case 102 and the opposing structure will be described with reference to FIG. The plate-shaped sealing material 120 has a protrusion that allows elastic deformation, and is formed of a material having a lower thermal conductivity than the material forming the inverter case 102. It is a stainless steel metal sealing material. In this structure, the inner peripheral end surface and the outer peripheral end surface of the inverter case 102 are formed in the same plane, and the two locations of the inner periphery and the outer periphery are formed as an integral plate-shaped sealing material 120.

  As described above, the inverter-integrated electric compressor according to the present invention is smaller, lighter, and more efficient than the conventional electric compressor with a built-in inverter, and further, the electronic component is improved by improving the inverter cooling efficiency. Reliability is also improved. This facilitates mounting on the 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 1 is an exploded structural view of the cooling passage space of the inverter case shown in FIG. Partial sectional view of the O-ring seal shown in FIG. Partial sectional view of a metal seal portion in the second embodiment Sectional drawing of the conventional electric compressor described in Patent Document 1 Sectional drawing of the conventional electric compressor described in Patent Document 2

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric compressor 2 Mounting leg 3 Main body casing 3a Sealing groove 3b O-ring 3c Minute gap 4 Compression mechanism part 5 Electric motor 5a Stator 6 Liquid storage part 7 Lubricating oil 8 Inlet 9 Discharge port 10 Compression space 11 Fixed spiral part 11a Fixation End plate 11b Seal groove 11c O-ring 11d Small gap 12 Swirl spiral part 12a Swivel end plate 13 Pump 14 Drive shaft 15 Oil supply path 17 Annular member 21 Liquid reservoir 22 Liquid reservoir 23 Restriction 24 Tip seal 25 Holding groove 30 Refrigerant 31 Discharge hole 41 Sub bearing 42 main bearing 43 eccentric bearing 51 main bearing member 52 lid body 53 pump chamber 54 suction passage 57 Oldham ring 61 suction chamber 62 discharge chamber 63 communication passage 65 lid body 70 suction passage space 71 passage hole 75 guide fin 80 tomewa 81 lead wire 82 Communication path 101 Motor drive circuit section 1 2 inverter case 102a endwall 103 circuit board 105 IPM
106 Compressor terminal 107 Harness connector 113 Inverter cover 114 Anodized surface treatment layer 120 Plate-shaped sealing material

Claims (1)

A compression mechanism section that sucks, compresses and discharges fluid; a main body casing that includes a motor that drives the compression mechanism section; an inverter case that includes an inverter that drives the motor; and an inverter cover that seals the inverter case The compression mechanism portion is housed in the main body casing, and is sandwiched and fixed by an inner peripheral end surface of the inverter case and an inner surface stepped portion of the main body casing, and between the end surface of the main body casing and the outer peripheral end surface of the inverter case. It is a structure that is sealed with a sealing material in between, and a refrigerant suction passage is provided in a sealed space that is configured by installing a sealing material between the inner peripheral end face of the inverter case and the end face of the compression mechanism section. An inverter-integrated electric compressor that cools the back surface of the inverter installation wall ,
The sealing material is provided with a sealing groove on either one of the facing end faces, leaving a maximum portion between the inner peripheral end face of the inverter case and the end face of the compression mechanism, and the end face of the inverter case and the end face of the main casing. And a gap within the elastic range of the sealing material over the entire circumference,
The inverter case and the inverter cover are made of an aluminum alloy, and an inverter-integrated electric compressor in which at least one surface is anodized .