JP2008082266A - Electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a lowering in the cooling efficiency of an inverter circuit 30, in an electric compressor 100. <P>SOLUTION: In this electric compressor 100, an elastic member 60 is sandwiched between an inverter cover 21 and the inverter circuit 30 to be elastically deformed and made in a compressed state. Therefore, even though the height dimension (Lz) of the inverter cover 21 and the height dimension (La) of the inverter circuit 30 are varied, the elastic member 60 is elastically deformed to absorb variations in height dimensions, and pushes the inverter circuit 30 to the side of the mounting surface 16 of a motor housing 11 by elastic force. Since the inverter circuit 30 is tightly stuck to the mounting surface 16, the inverter circuit 30 is sufficiently cooled by a refrigerant in a refrigerant channel 11d. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric compressor that drives a compressor by an electric motor.

Conventionally, in an electric compressor, as shown in FIG. 9, the inverter circuit 4 is disposed on the outer surface 3 a of the housing 3 that houses the compressor 1 and the electric motor 2, and the inverter cover 5 is disposed so as to cover the inverter circuit 4. Further, there is a configuration in which the inverter cover 5 is fastened to the housing 3 and the inverter circuit 4 is cooled by the refrigerant flowing in the housing 3 as the compressor 1 is compressed (for example, Patent Document 1). reference).
JP 2004-190547 A

  In the electric compressor described above, the height dimension Lz of the inverter cover 5 and the height dimension La of the inverter circuit 4 vary, and the inverter circuit 4 is larger than the dimension Lb between the outer surface 3a of the housing 3 and the inverter cover 5. The height dimension La becomes smaller, and a gap S may be generated between the inverter circuit 4 and the inverter cover 5.

  Therefore, the inverter circuit 4 cannot be brought into close contact with the outer surface 3 a of the housing 3. For this reason, heat exchange between the refrigerant flowing as indicated by the arrow T in the housing 3 and the inverter circuit 4 cannot be sufficiently performed, and the cooling efficiency of the inverter circuit (motor drive circuit) 4 is lowered.

  In view of the above points, an object of the present invention is to provide an electric compressor that suppresses a decrease in cooling efficiency of a motor drive circuit even if dimensional variation occurs.

  In order to achieve the above object, in the present invention, the fluid flows in the housing as the compressor sucks, compresses and discharges the fluid, and the motor drive circuit is driven by the fluid flowing in the housing through the housing. An electric compressor adapted to be cooled and disposed in an elastically deformed and contracted state between a cover for an electric circuit and a motor drive circuit, and the motor drive circuit is arranged on the outer wall surface side of the housing by elastic force A first feature is to provide an elastic member that is pressed against and closely contacts.

  Therefore, even if the height dimension (La) of the motor drive circuit and the height dimension (Lz) of the electric circuit cover vary, the elastic member is elastically deformed to absorb the variation of the dimension. Then, the motor drive circuit can be pressed against the outer wall surface of the housing to be brought into close contact therewith. For this reason, heat exchange between the refrigerant flowing in the housing and the motor drive circuit can be performed satisfactorily, and it is possible to suppress a decrease in cooling efficiency of the motor drive circuit even if dimensional variation occurs.

  Here, the height dimension (La: see FIG. 9) of the motor drive circuit is a dimension in a direction in which the electric circuit cover and the housing intersect each other in the motor drive circuit. Moreover, the height dimension (Lz: refer FIG. 9) of the cover for electric circuits is a dimension of the direction for crossing the cover for electric circuits and a housing among the covers for electric circuits.

  In the present invention, the motor drive circuit is formed so as to surround the periphery of the motor drive circuit, and is disposed in an elastically deformed and contracted state between the electric circuit cover and the outer wall surface of the housing. A second feature is that a seal member for sealing between the wall surfaces is provided.

  Therefore, since the space between the electric circuit cover and the outer wall surface of the housing can be sealed, it is possible to prevent foreign matter from entering the electric circuit cover.

  In addition, the code | symbol in the bracket | parenthesis of each means described in a claim and this column shows the correspondence with the specific means as described in embodiment mentioned later.

  1 to 4 show an electric compressor 100 according to an embodiment of the present invention. 1 shows the configuration of a refrigeration cycle apparatus to which the electric compressor 100 of the present embodiment is applied, FIG. 2 shows the internal configuration of the electric compressor 100 viewed from a direction orthogonal to the rotation axis, and FIG. 3 shows the electric compressor The internal structure which looked at 100 from the axial direction of the rotating shaft is shown.

  As shown in FIG. 1, the electric compressor 100 constitutes a refrigeration cycle device for a vehicle air conditioner together with a condenser 101, a decompressor 102, and an evaporator 103.

  As shown in FIG. 2, the electric compressor 100 includes an electric motor unit 10, a compressor 20, and an inverter circuit 30. The electric motor unit 10 rotationally drives the compressor 20 via the rotary shaft 12. Specifically, the electric motor unit (electric motor) 10 includes a motor housing 11, a rotating shaft 12, a rotor 13, a stator core 14, and a stator coil 15.

  The motor housing 11 is made of a metal such as iron having high heat conductivity, and is formed in a substantially cylindrical shape centering on the rotating shaft 12. A refrigerant suction port is provided at one end side in the axial direction Z of the motor housing 11. (Fluid suction port) 11a is provided.

  Here, a refrigerant discharge port 11 b (fluid discharge port) is provided on the other end side in the axial direction Z of the motor housing 11. A mounting surface 16 on which the inverter circuit (motor drive circuit) 30 is mounted is formed in the direction perpendicular to the axis of the outer wall of the motor housing 11. The axis orthogonal direction is a direction orthogonal to the rotation axis 12. The motor housing 11 corresponds to the housing described in the claims.

  The rotating shaft 12 is disposed in the motor housing 11 and is rotatably supported by a bearing 12a and another bearing (not shown). The rotating shaft 12 transmits the rotational driving force received from the rotor 13 to the compressor 20. The bearing 12 a and other bearings are supported by the motor housing 11.

  The rotor 13 is made of a permanent magnet and is formed in a cylindrical shape having a hollow portion. The rotary shaft 12 is press-fitted into the hollow portion, and the rotor 13 and the rotary shaft 12 are fixed. The rotor 13 rotates together with the rotating shaft 12 based on the rotating magnetic field generated from the stator core 14.

  The stator core 14 is disposed radially outward with respect to the rotor 13 (rotating shaft 12), and the stator core 14 is formed in a substantially annular shape within the motor housing 11. The stator core 14 is made of a magnetic material and is supported from the inner peripheral surface of the motor housing 11. The stator coil 15 is wound around the stator core 14.

  Here, a refrigerant channel 11d is formed between the mounting surface 16 side of the motor housing 11 and the stator core 14, and the refrigerant channel 11d is a refrigerant (in order to cool the inverter circuit 30 as described later). Fluid).

  The compressor 20 is a rotary type compressor, and the compressor 20 is swung by the rotational driving force from the rotating shaft 12 of the electric motor unit 10 to suck, compress, and discharge the refrigerant.

  The inverter circuit 30 is mounted on the mounting surface (outer wall surface) 16 of the motor housing 11. The inverter circuit 30 is composed of a semiconductor element or the like, and constitutes a drive electric circuit that supplies power to the stator coil 15 of the electric motor unit 10 to drive the electric motor unit 10.

  Here, in order to connect between the inverter circuit 30 and the stator coil 15, the cluster block 40 and the airtight terminal 50 are used.

  The cluster block 40 constitutes a stator-side connector to which the end of the stator coil 15 is connected. The cluster block 40, together with the airtight terminal 50, is the axial end portion side (Z direction end portion side) of the stator core 14. , The stator core 14 and the compressor 20 are disposed.

  The airtight terminal 50 is fitted in the opening 17 of the motor housing 11, and the airtight terminal 50 includes three needle-like terminals (one needle-like terminal in FIG. 2) that penetrates the inside and outside of the motor housing 11. Only show). The other end sides of the three needle terminals are connected to the cluster block 40, respectively.

  On the other hand, an inverter cover 21 is provided to fix the inverter circuit 30 to the motor housing 11, and the inverter cover 21 is a metal member formed so as to cover the inverter circuit 30.

  Specifically, as shown in FIGS. 2 and 3, the inverter cover 21 includes an upper surface portion 21 b that sandwiches the inverter circuit 30 together with the mounting surface 16, a protrusion protruding from the upper surface portion 21 b toward the mounting surface 16, and an inverter. An annular side portion 21 a formed so as to surround the circuit 30 is provided. As shown in FIG. 4, the inverter cover 21 is fastened to the motor housing 11 with four bolts Ba. 4 is a view taken in the direction of arrow Y in FIG.

  Here, between the upper surface portion 21 b of the inverter cover 21 and the inverter circuit 30, a plate-like elastic member 60 made of rubber, sponge or the like is sandwiched.

  FIG. 5 shows a top view of the elastic member 60 (viewed from the inverter cover 21 side). The elastic member 60 has four triangular openings 61a, and the four openings 61a penetrate between the upper surface portion 21b of the inverter cover 21 and the inverter circuit 30, and the inverter cover 21 and the inverter A non-contact portion that does not contact the circuit 30 is formed.

  On the other hand, the region 61b of the elastic member 60 other than the four triangular holes 61a is formed in a substantially X shape so as to follow a diagonal line, thereby forming a contact portion that contacts the upper surface portion 21b of the inverter cover 21.

  Further, a seal member 70 is provided between the annular side portion 21a of the inverter cover 21 and the motor housing 11, as shown in FIG. 2 or FIG. The seal member 70 is formed to have an annular shape and a circular cross section so as to surround the inverter circuit 30, and is made of, for example, an elastic material such as rubber. The seal member 70 seals between the annular side portion 21 a of the inverter cover 21 and the motor housing 11.

  Next, assembly of the inverter cover 21 and the inverter circuit 30 will be described.

  First, the inverter circuit 30 is disposed on the mounting surface 16 of the motor housing 11, and then the elastic member 60 is disposed on the inverter circuit 30. Further, a seal member 70 is disposed on the motor housing 11. Thereafter, the elastic member 60 is pressed against the motor housing 11 by the inverter cover 21, and the inverter cover 21 is fastened to the motor housing 11 with the four bolts Ba in this state.

  At this time, the elastic member 60 is pressed from the inverter cover 21 and is elastically deformed to be in a compressed state. For this reason, the elastic member 60 presses the inverter circuit 30 against the mounting surface 16 side of the motor housing 11 by elastic force.

  The seal member 70 is compressed by elastic deformation between the annular side portion 21 a of the inverter cover 21 and the motor housing 11, and seals between the annular side portion 21 a of the inverter cover 21 and the motor housing 11.

  Next, the operation of the electric compressor 100 of the present embodiment will be described.

  First, the inverter circuit 20 is turned on, and a driving current is supplied to the stator coil 15 of the electric motor unit 10. Along with this, a rotating magnetic field is generated from the stator core 14, and thus a rotational force is generated on the rotor 13. Then, the rotor 13 rotates with the rotating shaft 12. Therefore, the compressor 30 is turned by the rotational driving force from the rotary shaft 12 to suck, compress, and discharge the refrigerant.

  Here, the refrigerant from the evaporator side flows into the refrigerant suction port 11a side of the motor housing 11, and the refrigerant flows in the refrigerant channel 11d in the axial direction as indicated by the arrow R in FIG. Flowing. Thereafter, the refrigerant is compressed by the compressor 30 and discharged from the refrigerant discharge port 11b to the condenser side.

  On the other hand, although the inverter circuit 20 generates heat during operation, the inverter circuit 30 is pressed against the mounting surface 16 side of the motor housing 11 by the elastic force of the elastic member 60, so that the inverter circuit 30 is in close contact with the mounting surface 16. Yes. For this reason, the inverter circuit 30 exchanges heat with the refrigerant in the refrigerant flow path 11d while being in close contact with the mounting surface 16.

  According to this embodiment described above, the elastic member 60 is sandwiched between the inverter cover 21 and the inverter circuit 30, and is elastically deformed to be in a compressed state. Therefore, even when variations in the height dimension (Lz) of the inverter cover 21 and the height dimension (La) of the inverter circuit 30 occur, the elastic member 60 is elastically deformed and absorbs the dimension variation, and is elastic. The inverter circuit 30 can be pressed against the mounting surface 16 side of the motor housing 11 by force. For this reason, since the inverter circuit 30 can be adhered to the mounting surface 16, the inverter circuit 30 is sufficiently cooled by the refrigerant in the refrigerant flow path 11d.

  Further, as described above, the seal member 70 is elastically deformed between the annular side portion 21a of the inverter cover 21 and the motor housing 11, and seals between the annular side portion 21a of the inverter cover 21 and the motor housing 11. Therefore, it is possible to prevent foreign matter from entering the inside of the inverter cover 21.

  Here, due to variations in the height dimension (Lz) of the inverter cover 21 and the height dimension (La) of the inverter circuit 30, a variation in the dimension Lb between the inverter cover 21 and the motor housing 11 occurs. This dimensional variation Lb can be absorbed by the elastic deformation of the seal member 70.

  That is, when the dimension Lb between the inverter cover 21 and the motor housing 11 is large, the seal member 70 is elastically deformed small, while when the dimension Lb is small, the seal member 70 is largely elastically deformed to absorb the variation of the dimension Lb. Thus, the space between the annular side portion 21a of the inverter cover 21 and the motor housing 11 can be sealed.

(Other embodiments)
In the above-described embodiment, the example in which the sealing member 70 having a circular cross section is used has been described. Instead, as shown in FIG. 6, as the sealing member 70, the annular side of the inverter cover 21 is used. You may use what has the protrusion part 71 which protrudes in the motor housing 11 side from the part 21a side. Further, as the seal member 70, a member having a protruding portion 71 protruding from the motor housing 11 side to the annular side portion 21a side of the inverter cover 21 may be used.

  In this case, when the dimension Lb between the inverter cover 21 and the motor housing 11 is large, the projecting portion 71 of the seal member 70 is elastically deformed small, while when the dimension Lb is small, the seal member 70 is elastically deformed largely. As a result, variations in the height dimension (Lz) of the inverter cover 21 and the height dimension (La) of the inverter circuit 30 can be absorbed, and the gap between the inverter cover 21 and the motor housing 11 can be sealed.

  In particular, since the seal member 70 has the protruding portion 71, the variable range of elastic deformation of the seal member 70 can be made larger than that of the seal member 70 having the circular cross section of the above-described embodiment. Even if the height dimension (Lz) 21 and the height dimension (La) of the inverter circuit 30 are increased, the variation can be absorbed.

  In the above-described embodiment, an example in which a plate-like elastic member made of rubber, sponge, or the like is used as the elastic member 60 has been described. Instead, a coil spring or the like is used as the elastic member 60. Also good.

  Further, as the elastic member 60, a metal plate spring 60 shown in FIGS. 7 and 8 may be used. 7 is a view of the plate spring 60 viewed from the inverter cover 21 side, and FIG. 8 is a cross-sectional view taken along the line CC in FIG.

  Specifically, the plate-like spring (plate-like member) 60 has six movable parts 62 (this corresponds to the movable part described in claim 5), and the six movable parts 62 are plate-like. Part of the spring 60 is cut and raised on the inverter cover 21 side (or on the inverter circuit 30 side).

  Accordingly, each movable portion 62 of the plate spring 60 is pressed by the inverter cover 21 and elastically deforms. Therefore, the remaining portion other than each movable portion 62 of the plate spring 60 houses the inverter circuit 30 by its elastic force. 11 will be pressed. For this reason, the inverter circuit 30 can be adhered to the housing 11.

  In addition, the movable part 62 of the leaf | plate spring 60 does not need to be six places, and the direction cut and raised does not need to be the same. The direction to be cut and raised may be a facing direction, a radial direction, or the like.

It is a mimetic diagram showing the refrigerating cycle device to which the electric compressor concerning the present invention is applied. It is a figure which shows the internal structure of the electric compressor which concerns on the above-mentioned embodiment. It is a figure which shows the internal structure of the electric compressor which concerns on the above-mentioned embodiment. FIG. 3 is a top view of the inverter cover in FIG. 2. FIG. 3 is a top view of the elastic member in FIG. 2. It is sectional drawing which shows the modification of the sealing member in FIG. It is sectional drawing which shows the modification of the elastic member in FIG. It is CC sectional drawing in FIG. It is a figure which shows the internal structure of the conventional electric compressor.

Explanation of symbols

11 ... motor housing,
11d ... Refrigerant flow path, 16 ... Mounting surface 30 ... Inverter circuit, 51 ... Inverter cover,
60 ... elastic member, 100 ... electric compressor,
Lz: Inverter cover height dimension, La: Inverter circuit height dimension.

Claims (6)

A housing having a fluid inlet and a fluid outlet;
A compressor that is housed in the housing, sucks and compresses fluid from the fluid suction port, and discharges the fluid from the fluid discharge port;
An electric motor housed in the housing and driving the compressor;
A motor drive circuit mounted on the outer wall surface of the housing and supplying power to the electric motor;
An electric circuit cover formed to cover the motor drive circuit and attached to the housing;
The fluid flows in the housing as the compressor sucks, compresses and discharges the fluid;
An electric compressor in which the motor drive circuit is cooled by a fluid flowing through the housing through the housing,
An elastic member that is sandwiched in an elastically deformed state between the electric circuit cover and the motor drive circuit, and that presses the motor drive circuit against the outer wall surface of the housing by an elastic force to be in close contact with the motor drive circuit. Electric compressor to do. The elastic member includes a compressed part that is sandwiched between the electric circuit cover and the motor drive circuit and is compressed by elastic deformation, and a non-contact part that is not in contact with the electric circuit cover side. Consisting of
The force applied to the compressed part from the electric circuit cover side is set by setting the contact area that contacts the electric circuit cover side of the compressed part, and presses the motor drive circuit against the housing side The electric compressor according to claim 1, wherein an elastic force of the portion to be compressed is set. The electric compressor according to claim 2, wherein the non-contact portion of the elastic member is an opening penetrating between the electric circuit cover side and the motor drive circuit side. The electric compressor according to claim 1, wherein the elastic member is a spring member. The elastic member includes a plate-like member having a movable part cut and raised on one side of the electric circuit cover and the motor drive circuit,
The plate-like member is elastically deformed when one of the electric circuit cover and the motor drive circuit is pressed against the movable portion, and the motor drive circuit is pressed against the housing by the elastic force accompanying the elastic deformation. The electric compressor according to claim 1. The motor drive circuit is formed so as to surround the periphery, and is disposed in a state of being elastically deformed and contracted between the electric circuit cover and the outer wall surface of the housing, and the electric circuit cover and the housing The electric compressor according to claim 1, further comprising a seal member that seals between the outer wall surface.

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