JP2012026310A - Inverter-integrated electric compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inverter-integrated electric compressor that can efficiently cool an inverter without enlarging a body casing.SOLUTION: The inverter-integrated electric compressor includes: the body casing 3 housing a compression mechanism part 5 and a motor 4; and an inverter case 6 that is installed to cover the compression mechanism part of the body casing 3 and that houses an inverter 7 for driving the motor. The inverter case 6 forms an intake chamber 28 between the inverter case 6 and the compression mechanism part 5 and an ejection chamber 30 connecting to an ejection port of the compression mechanism part so that the ejection chamber 30 is located in the intake chamber. The intake chamber includes a sidewall 11c for partitions the intake chamber 28 into the ejection chamber 30, and a lid body 37 for lidding the sidewall. An annular groove 11d that is taller than the sidewall and a heating insulation member 41 having a heat lower transfer rate are disposed around the sidewall, which can prevent an intake coolant from being heated due to the heat transfer from a high-temperature gas of the ejection chamber 30. Accordingly, the cooling effect of the inverter 7 can be improved.

Description

  The present invention relates to an inverter-integrated electric compressor including a compression mechanism section, an electric motor, and an inverter that drives the electric motor.

  Conventionally, this type of inverter-integrated electric compressor has a configuration in which an inverter, a compression mechanism, and an electric motor are partitioned and provided integrally (see, for example, Patent Document 1).

  FIG. 4 is a longitudinal sectional view of the inverter-integrated electric compressor described in Patent Document 1, and is arranged so as to cover the main body casing 113 containing the electric motor 111 and the compression mechanism 112, the compression mechanism 112, and the inverter. The inverter case 115 containing the 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 112 is once led to a suction chamber 117 composed of the inverter case 114 and the end plate of the fixed scroll 119, and heat exchange with the inverter 114 is achieved. Then, it is sucked into the compression mechanism 112 after being cooled. Further, the refrigerant gas compressed by the compression mechanism unit 112 is discharged into the discharge chamber 120 provided in the suction chamber 117, guided into the main body casing 112 through the communication path 121, and after cooling the electric motor 111, The ink is discharged from the provided discharge port 118. This is a typical structure in a so-called high-pressure compressor.

JP 2007-290444 A

  However, in the conventional configuration, the suction chamber 117 is configured by the inverter case 115 and the end plate of the fixed scroll so that the suction refrigerant can be used for inverter cooling while reducing the size of the entire compressor. Since the discharge hole 122 of the compression mechanism unit 112 is configured, a discharge chamber 120 from which high-temperature gas is discharged from the compression mechanism unit 112 is also provided in the suction chamber 117. The intake refrigerant is heated by heat transfer, and the cooling capacity of the inverter 114 is reduced. In addition, there is a problem that causes deterioration in performance due to a decrease in volumetric efficiency.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and mainly aims to provide an inverter-integrated electric compressor that can efficiently cool an inverter without increasing the size of a main body casing and is excellent in performance. .

  In order to solve the above-described conventional problems, an inverter-integrated electric compressor according to the present invention includes a suction chamber formed by an inverter case and a compression mechanism, and an inverter-integrated compression in which a discharge chamber is formed in the suction chamber. In this machine, an annular groove having a depth substantially equal to the height of the side wall is formed on the entire circumference of the side wall forming the discharge chamber, and a heat insulating member having a low heat transfer coefficient is disposed.

  Thereby, while maintaining the downsizing by providing the discharge chamber in the suction chamber, it is possible to suppress the heating of the suction refrigerant due to the heat transfer through the side wall between the discharge chamber and the suction chamber due to the high temperature gas in the discharge chamber. Since the cooling effect of the heat generating components can be enhanced, the performance and reliability can be improved.

  The inverter-integrated electric compressor of the present invention can improve the cooling efficiency of inverter parts without increasing the size of the main casing, and can be directly mounted on an engine such as a hybrid vehicle to heat, vibrate, etc. from the engine. Even in the harsh environment, it is possible to operate without impairing performance and reliability.

1 is a longitudinal sectional view of an inverter-integrated electric compressor according to Embodiment 1 of the present invention. Exploded perspective view of the same discharge chamber Expanded sectional view of the discharge chamber Vertical section of a conventional inverter-integrated electric compressor

  A first aspect of the present invention is a main body casing incorporating a rear portion of a compressor and an electric motor that drives the compression mechanism portion, and an inverter that is attached so as to cover the compression mechanism portion side of the main body casing and that drives the electric motor. A case in which the inverter case forms a suction chamber with the compression mechanism, and forms a discharge chamber in communication with a discharge port of the compression mechanism so as to be positioned in the suction chamber. Comprises a side wall that partitions the suction chamber and the discharge chamber and a lid that closes the side wall, and an annular groove having a height approximately equal to or higher than the side wall height is provided on the entire circumference of the side wall to provide a heat transfer coefficient. The low-temperature heat insulating member is arranged, and the heating of the suction refrigerant due to the heat transfer through the side wall between the discharge chamber and the suction chamber due to the high temperature gas in the discharge chamber can be suppressed. To enhance the cooling effect of the heat-generating components in the converter case, it is possible to improve the performance and reliability.

  The second invention is a heat insulating member in the side wall of the first invention in particular, and is configured to seal between the side wall of the discharge chamber and the lid, and there is no need to provide a seal member separately from the heat insulating member. Further, the side wall of the discharge chamber can be made thin, the increase in the size of the main body casing can be suppressed, and the deterioration of the assemblability can be suppressed.

  In the third invention, in particular, the heat insulating member in the side wall of the second invention is manufactured with a two-layer structure of an elastic body and an inelastic body, and the sealing between the side wall of the discharge chamber and the lid body is performed on the elastic body side. Yes, the crushing allowance and crushing ratio as a sealing member can be set effectively regardless of the groove depth, and the leakage from the discharge chamber to the suction chamber due to the deterioration of the sealing performance due to the thermal deterioration of the heat insulating member is suppressed. A decrease in reliability can be suppressed.

  The fourth invention has a configuration in which a convex shape that fits the entire circumference of the annular groove portion of the side wall is formed on the assembly surface on the side wall upper surface side of the lid body of the third invention. The force applied to the inside of the side wall by the discharge gas can be supported by the convex part of the lid, preventing deformation and breakage of the side wall, suppressing leakage from the discharge chamber to the suction chamber, and suppressing deterioration in performance and reliability. Can do.

  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 electric compressor according to Embodiment 1 of the present invention, FIG. 2 is an exploded perspective view of the discharge chamber, and FIG. 3 is an enlarged sectional view of the discharge chamber.

FIG. 1 shows, as an example, a horizontal electric compressor that is installed sideways by a mounting leg 2 around a body portion of the electric compressor 1, and the electric compressor 1 is placed in the main body casing 3. 4 is built in and the compression mechanism part 5 inserted in this main body casing 3 or press-fit is driven. An inverter case 7 in which an inverter 6 is incorporated is attached and fixed to one end opening side (left side in FIG. 1) of the main body casing 3 with bolts (not shown) so as to cover the opening. The electric motor 4 is driven by an inverter 7 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 fixed scroll 11 and the fixed scroll plate 11a of the orbiting scroll 12 and the blades rising from the swivel end plate 12a are meshed to form a compression space 10. Then, the volume of the compression space 10 is changed by causing the orbiting scroll 12 to circularly move with respect to the fixed scroll 11 via the drive shaft 13 by the electric motor 4, and the suction, compression and refrigerating of the refrigerant 14 returning from the external cycle are performed. Discharge to the external cycle is performed through a suction port 15 provided in the inverter case 6 and a discharge port 16 provided in the main body casing 3.

  A main bearing member 20 having a pump 17, a sub-bearing 18, an electric motor 4, and a main bearing 19 is disposed from the other side wall 3 a (right side in FIG. 1) in the axial direction 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 4 a is shrink-fitted and fixed to the main body casing 3, or is fixed by a bolt 24, and the drive shaft 13 can be rotationally driven by the rotor 4 b fixed around the drive shaft 13. 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 the Oldham ring 26 and causing the circular movement is provided. It is connected to the scroll 12 so that the orbiting scroll 12 can be turned on a circular path.

  When the inverter case 6 is attached to the main body casing 3, the suction chamber 28 is formed by airtightly combining the space communicating from the suction port 15 with the fixed end plate 11 a of the fixed scroll 11 using the 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. By providing the discharge chamber 30 in the suction chamber 28 in this way, the length in the main body casing axial direction can be shortened, that is, the size can be reduced. A through passage (not shown) 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 6a of the inverter case 6 that covers the opening of the main casing 3. 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 is demonstrated using FIG.2 and FIG.3. 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, and FIG. 3 is an enlarged sectional view of the discharge chamber 30. The discharge chamber 30 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 is formed by sealing a lid 37 formed of a heat insulating member with a bolt 38 on a substantially quadrangular side wall 11c formed so as to surround the discharge hole 29 of the fixed end plate 11a. It is configured to be fixed, and is 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.

  Here, in this embodiment, as shown in FIG. 3, an annular groove 11d having a depth substantially equal to or greater than the side wall height is formed in the side wall 11c of the discharge chamber 30, and a heat insulating member 41 is disposed. ing. The heat insulating member 41 has a two-layer structure including an elastic body 41a and a non-elastic body 41b in the vertical direction. Further, the lid body 37 is formed with a convex portion 37a that fits into the annular groove 11d.

  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 configured in the suction chamber 28.

  The refrigerant discharged from the discharge hole 29 to the discharge chamber 30 is transferred to the suction chamber 23 by the heat insulating member 41 inserted into the annular groove 11d in the side wall 11c of the discharge chamber 30 and the lid 37 formed of the heat insulating member. While maintaining the heat insulating property of the fixed scroll 11, it enters the electric motor 4 side through a communication passage 31 formed between the 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, and cools the electric motor 4. In the long process until it is discharged from the discharge port 16 of the main casing 3, the refrigerant undergoes various gas-liquid separations such as collision, centrifugation, throttling, etc., and is subjected to separation of the lubricating oil 9 but is accompanied by partial lubrication. The auxiliary bearing 18 is also lubricated by the oil 9.

  In this way, the annular groove 11d having a depth substantially equal to or higher than the side wall height is formed in the side wall 11c in the side wall 11c partitioning the suction chamber 28 and the discharge chamber 30, and the heat insulating member 41 having a low heat transfer coefficient is disposed. By doing so, heating of the suction refrigerant 14 due to heat transfer through the side wall 11c between the discharge chamber 30 and the suction chamber 28 due to the high temperature gas in the discharge chamber 30 can be suppressed, and cooling of the heat generating components in the inverter case 6 can be suppressed. Since the effect can be enhanced, the performance and reliability can be improved.

  Further, by sealing between the side wall 11c of the discharge chamber 30 and the lid 37 with the heat insulating member 41 in the side wall 11c, it is not necessary to provide a seal member separately from the heat insulating member 41, and the side wall 11c of the discharge chamber 30 is eliminated. Can be configured thinly, the increase in size of the main body casing can be suppressed, and deterioration in assembly can be suppressed.

Further, the heat insulating member 41 in the side wall 11c has a two-layer structure of an elastic body 41a and a non-elastic body 41b, and sealing is performed between the side wall 11c of the discharge chamber 30 and the lid body 37 on the elastic body 41a side. The crushing allowance and crushing rate can be effectively set regardless of the groove depth, and leakage from the discharge chamber 30 to the suction chamber 28 due to a decrease in sealing performance due to thermal deterioration of the heat insulating member 41 can be suppressed, and performance and reliability can be reduced. Can be suppressed.

  Further, by forming a convex shape that fits the entire circumference of the annular groove 11d portion on the assembly surface on the upper surface side of the side wall 11c of the lid 37, the high temperature and high pressure discharge gas in the discharge chamber 30 causes the side wall 11c to Such a force can be supported by the convex portion of the lid body 37, deformation and breakage of the side wall 11c can be prevented, leakage from the discharge chamber 30 to the suction chamber 28 can be suppressed, and deterioration in performance and reliability can be suppressed. .

  In the above-described embodiment, the scroll compression type is described as the compression mechanism unit, but the present invention is not limited to this.

  As described above, the inverter-integrated electric compressor according to the present invention improves the cooling effect of the inverter while maintaining the miniaturization, and improves the reliability of the electronic components. 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 Electric motor 5 Compression mechanism part 6 Inverter case 6a End wall 7 Inverter 11 Fixed scroll 11a Fixed end plate 11c Side wall 11d Annular groove 12 Revolving scroll 14 Refrigerant 28 Suction chamber 29 Discharge hole 30 Discharge chamber 37 Cover body 41 heat insulation member 41a heat insulation member (elastic body part)
41b Thermal insulation member (non-elastic body part)

Claims (4)

A main body casing having a built-in motor that drives the rear portion of the compressor and the compression mechanism, and an inverter case having a built-in inverter that drives the electric motor and is attached so as to cover the compression mechanism portion side of the main body casing, The inverter case forms a suction chamber with the compression mechanism section and forms a discharge chamber communicating with the discharge port of the compression mechanism section so as to be positioned in the suction chamber. The discharge chamber is connected to the suction chamber and the discharge chamber. A side wall that divides the chamber and a lid that closes the side wall, and an annular groove having a height approximately equal to or higher than the side wall height is provided on the entire circumference of the side wall to provide a heat insulating member having a low heat transfer coefficient. The inverter-integrated electric compressor. The inverter-integrated electric compressor according to claim 1, wherein a seal between the side wall of the discharge chamber and the lid is performed by a heat insulating member in the side wall. 3. The inverter-integrated electric motor according to claim 2, wherein the heat insulating member in the side wall is formed by a two-layer structure of an elastic body and an inelastic body, and seals between the side wall of the discharge chamber and the lid on the elastic body side. Compressor. 4. The inverter-integrated electric compressor according to claim 2, wherein a convex shape is formed on the upper surface side of the side wall of the lid so as to be fitted to the entire circumference of the annular groove portion of the side wall.