JP5592850B2 - Electric compressor - Google Patents

Description

The present invention relates to an electric compressor having a motor driven by power supply from a battery or the like. This type of electric compressor can be used as a compressor for compressing a refrigerant in an in-vehicle air conditioner.

For example, Patent Document 1 discloses an electric compressor for compressing refrigerant in which a compression unit and a motor are integrated. In the electric compressor, a drive circuit for driving the motor is attached to the refrigerant gas suction side of the compressor. The drive circuit uses a power supply smoothing capacitor as one of the components of the inverter. According to this structure, since there is no air-cooled radiator or fan, water-cooled water-cooled radiator or water pipe, the size, cost and assembly time can be reduced. In addition, long lead wires are not necessary. Furthermore, there is an advantage that the emission of electromagnetic noise is reduced and the radio and other in-vehicle devices are not adversely affected.

However, since a large ripple current flows through the power supply smoothing capacitor, heat generation increases. In addition, it is necessary to use a large capacitor, which increases the cost. In addition, since the drive circuit is a separate structure that is built into the electric compressor, a large power supply smoothing capacitor is mounted in a protruding form on the electric compressor housing, and the inverter built-in type electric compressor is large. Turn into.

JP 2000-291557 A

Therefore, an object of the present invention is to provide an inexpensive and small electric compressor in which heat dissipation of a power supply smoothing capacitor is promoted.

According to the present invention, a compression unit for compressing a refrigerant, an electric motor for driving the compression unit, a drive circuit for driving the electric motor including an inverter and a control circuit, and the compression unit And a common housing having a suction housing made of a metal material for containing the electric motor and sucking in the refrigerant, the electric compressor used for an in-vehicle air conditioner, wherein the drive circuit is provided for the suction housing. A capacitor-accommodating chamber dedicated to a capacitor that is attached to the outer surface of the wall and is cooled by the suction refrigerant is provided integrally with the suction housing, and a power supply smoothing capacitor connected between an external DC power source and the drive circuit is the capacitor. Housed in a housing chamber, the capacitor housing chamber containing the power smoothing capacitor has an opening. An electric compressor characterized by this can be obtained.

The power smoothing capacitor may be in close contact with the suction housing via the capacitor housing chamber, and the heat sink of the power smoothing capacitor may be dissipated by the suction housing and the capacitor housing chamber cooled by the sucked refrigerant. It is characterized by promoting.

According to the present invention, it is possible to provide an inexpensive and small electric compressor in which heat dissipation of the power supply smoothing capacitor is promoted.

It is sectional drawing which shows the electric compressor which concerns on the 1st Embodiment of this invention. It is sectional drawing of the electric compressor which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the electric compressor which concerns on the 3rd Embodiment of this invention. FIG. 4 is a circuit diagram mainly showing a configuration of a motor drive circuit that can be used in each of the electric compressors of FIGS. 1 to 3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing an electric compressor according to a first embodiment of the present invention. The electric compressor shown in FIG. 1 includes a discharge housing 11 made of a metal material containing aluminum, an intermediate housing 12, and a suction housing 13. The discharge housing 11, the intermediate housing 12, and the suction housing 13 are connected by bolts 14a and 14b to form a common housing 15.

The discharge housing 11 includes a discharge port 16 on the end surface. A fixed scroll member 17 fixed to the discharge housing 11 and a movable scroll member 18 facing the fixed scroll member 17 are arranged in the discharge housing 11, and the refrigerant is compressed by the fixed and movable scroll members 17 and 18. A compression unit 19 is configured.

The fixed scroll member 17 includes a bottom plate 21, a spiral body 22 provided on one surface of the bottom plate 21, and a fixing portion 23 provided on the other surface of the bottom plate 21. The fixing portion 23 is fixed to the end wall of the discharge housing 11 by screws 24.

The movable scroll member 18 includes a bottom plate 26, a spiral body 27 provided on one surface of the bottom plate 26, and a boss portion 28 protruding in a cylindrical shape from the other surface side of the bottom plate 27. Between the surface of the bottom plate 26 around the boss portion 28 and one end of the intermediate housing 12, there is provided a rotation prevention mechanism 29 comprising an Oldham coupling that prevents the movable scroll member 18 from rotating and enables a turning motion. Yes.

A rotating shaft 31 extending from the intermediate housing 12 to the suction housing 13 is provided. One end 31 a of the rotating shaft 31 is supported via a bearing 34 in a protruding portion 33 that protrudes in a cylindrical shape from the partition wall 32 provided so as to cross the inside of the suction housing 13 toward the compression portion 19 side. Yes.

A motor (electric part) 35 is provided in the stator 36 provided on the inner wall of the intermediate housing 12 and the suction housing 13, a coil 37 provided around the stator 36, and provided in the stator 36. And a rotor 38 fixed to the rotating shaft 31.

A large-diameter portion 31 b is provided at the other end of the rotating shaft 31 and is supported in the intermediate housing 12 via a bearing 39. An eccentric pin 31c is provided so as to protrude from the end of the large-diameter portion 31b. The eccentric pin 31 c is inserted into an eccentric bush 42 supported by the boss portion 28 via a bearing 41.

The above configuration is almost the same as the electric compressor according to the prior art.

In the electric compressor of FIG. 1, a sealing terminal 43 is provided on the upper side of the partition wall 32 in the suction housing 13, and the right side and the left side of the partition wall 32 are isolated. A suction port 44 is provided on the end wall of the suction housing 13. The opening at the outer end of the suction housing 13 is sealed with a lid member 45. The lid member 45 may be made of aluminum or an aluminum alloy of the same material as that of the housing, or may be made of a plate-like sealing material containing iron or other magnetic material. good. The lid member 45 protects each electric circuit provided in the electric compressor from water and foreign matter, and prevents the electromagnetic noise from the drive circuit 46 and the like from being released to the outside.

On the outside of the partition wall 32, a control circuit 47 and an inverter 48 are integrated and attached as a drive circuit 46 in close contact with the partition wall 32 surface of the suction housing 13. The inverter 48 is connected to the sealed terminal 43.

Further, a capacitor accommodation chamber 49 is provided outside the upper outer wall of the suction housing 13, and a capacitor 51 is attached thereto. Thus, the capacitor 51 is in close contact with the suction housing 13. A connector 52 is provided on the side wall of the suction housing 13. The connector 52 is connected to an external power source via the capacitor 51. Electric power is supplied to the drive circuit 4 and the like through the connector 52. As will be described in detail later, the capacitor 51 is a power supply smoothing capacitor used for driving the motor.

According to the electric compressor having such a configuration, since the capacitor 51 is in close contact with the suction housing 13 that is cooled by the refrigerant gas during operation, heat dissipation of the capacitor 51 is effectively promoted. Therefore, the size of the capacitor 51 can be reduced, and an inexpensive and small electric compressor can be provided.

FIG. 2 is a sectional view showing an electric compressor according to a second embodiment of the present invention. Components similar to those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

In the electric compressor of FIG. 2, a capacitor housing chamber 53 that opens in the axial direction is provided inside the lower outer wall of the suction housing 13, and the capacitor 51 is inserted and attached to the capacitor housing chamber 53 from the axial end surface. . Thus, the capacitor 51 is in close contact with the suction housing 13.

According to this electric compressor, the same effect can be obtained, and further downsizing can be achieved.

FIG. 3 is a sectional view showing an electric compressor according to a third embodiment of the present invention. Components similar to those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

Also in the electric compressor of FIG. 3, a capacitor housing chamber 54 opened in a direction intersecting the axial direction is provided inside the lower outer wall of the suction housing 13, and the capacitor 51 is inserted and attached to the capacitor housing chamber 54. Yes. Thus, the capacitor 51 is in close contact with the suction housing 13. In addition, the direction of the capacitor | condenser 51 differs from the electric compressor of FIG.

The same effect can be obtained by this electric compressor.

FIG. 4 is a circuit diagram mainly showing the configuration of the drive circuit 46. The drive circuit 46 has the same configuration as the drive device disclosed in Japanese Patent Laid-Open No. 9-163791. In the drive circuit 46, a three-phase DC motor formed by coupling three exciting coils 64a, 64b, and 64c functions as the motor 35 described above.

The drive circuit 46 includes an inverter 48 having a predetermined number (six in this case) of transistors 61a, 61b, 61c, 63a, 63b, and 63c for supplying a phase current to the three-phase DC motor, and transistors 61a, 61b, And a control circuit 47 for generating a drive control signal for controlling the switching operation of 61c, 63a, 63b, and 63c. Here, as the three-phase direct current motor, a direct current (DC) brushless motor in which the rotor is made of a permanent magnet and the stator has the above-described three exciting coils 64a, 64b, 64c is used.

Each transistor 61a, 61b, 61c, 63a, 63b, 63c in the inverter 48 is distinguished into a plus side and a minus side, and is connected to a DC power source 65 and a control circuit 47 each comprising a battery for the three-phase DC motor 12, The positive side transistors 61a, 61b and 61c form an upper arm, and the negative side transistors 63a, 63b and 63c form a lower arm.

Furthermore, between the emitters and collectors of the transistors 61a, 61b, 61c, 63a, 63b, and 63c, free-wheeling diodes 66a, 66b, and 66c for recirculating back electromotive current generated from the three-phase DC motor to the DC power source, respectively. , 67a, 67b, 67c are connected. These diodes 66a, 66b, 66c, 67a, 67b, 67c are used when the three-phase DC motor is stopped, or when chopping is performed by pulse width modulation (PWM) driving (one or both of the lowest part and the highest part of the waveform). This is for returning the back electromotive force generated from the respective excitation coils 64a, 64b, 64c of the three-phase DC motor to the DC power source 65 at the time of OFF, and is a normal transistor (each transistor 61a, 61b, 61c, 63a, 63b, 63c) having the same current capacity is used. That is, the diodes 66a, 66b, 66c, 67a, 67b, and 67c serve to protect the transistors 61a, 61b, 61c, 63a, 63b, and 63c from being destroyed by the back electromotive voltage.

In addition, the pace side of each transistor 61a, 61b, 61c, 63a, 63b, 63c is connected to the control circuit 3, and the collector side of the upper arm (61a, 61b, 61c) and the lower arm (63a, 63b, 63c). The emitter side is connected to a DC power supply 65 for supplying power to each of the transistors 61a, 61b, 61c, 63a, 63b, and 63c, and a capacitor 51 is interposed between both poles of the DC power supply 65 as a power supply smoothing capacitor. Has been.

When stopping the electric compressor via the three-phase DC motor, the control circuit 47 turns off all of the transistors 61a, 61b, 61c, 63a, 63b, and 63c as a switching operation for a short time by a drive control signal. The lower arms (63a, 63b, 63c) are turned on for a predetermined time or longer with the upper arms (61a, 61b, 61c) turned off. Thereby, the electric compressor is stopped.

In the inverter 48, when the electric compressor is in a normal operation (operation) state, each transistor receives a drive control signal from the control circuit 47, and converts the DC voltage applied from the DC power source (battery) 65 into a three-phase. It converts into alternating current, and supplies it as a drive current to the three-phase direct current motor with which an electric compressor is equipped.

11
Discharge housing 12
Intermediate housing 13
Inhalation housing 15
Common housing 16
Discharge port 17
Fixed scroll member 18
Movable scroll member 19
Compression unit 29
Anti-rotation mechanism 31
Rotating shaft 32
Partition wall 35
Motor (electric part)
36
Stator 37
Coil 38
Rotor 43
Sealed terminal 44
Inhalation port 45
Lid member 46
Drive circuit 47
Control circuit 48
Inverter 49
Capacitor accommodation chamber 51
Capacitor 52
Connector 53
Capacitor accommodation chamber 54
Capacitor storage chamber 65
DC power supply

Claims (2)

Accommodates a compressor for compressing refrigerant, an electric motor for driving the compressor, a drive circuit for driving the electric motor comprising an inverter and a control circuit, and the compressor and the electric motor And a common housing having a suction housing made of a metal material for sucking the refrigerant, and in the electric compressor used for an in-vehicle air conditioner, the drive circuit is attached to an outer surface of the wall of the suction housing. A capacitor housing chamber dedicated to the capacitor cooled by the suction refrigerant is provided integrally with the suction housing, and a power supply smoothing capacitor connected between the external DC power source and the drive circuit is housed in the capacitor housing chamber , the condenser housing chamber in which the power supply smoothing capacitor is accommodated electrodeposition, characterized in that it has an opening Equation compressor.   The power smoothing capacitor is brought into close contact with the suction housing through the capacitor housing chamber, and the heat sink of the power smoothing capacitor is radiated by the suction housing cooled by the sucked refrigerant and the capacitor housing chamber. The electric compressor according to claim 1.

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