DEVICE FOR RADIATING HEAT OF CAPACITOR OF AN INVERTER IN AN ELECTRIC COMPRESSOR

Abstract

Disclosed herein is an apparatus for cooling an inverter of a vehicle which receives power supplied from a vehicle battery and controls the rotation speed of a motor. The apparatus includes an inverter housing configured to support the inverter, and a heat dissipation unit provided at a predetermined position in the inverter housing and configured to come into contact with an outer circumferential surface of the capacitor so that heat of the capacitor is transferred to the inverter housing.

Claims

1-15. (canceled)

16. An apparatus for cooling an inverter of a vehicle comprising: an inverter housing receiving the inverter, the inverter housing including a capacitor; and a heat dissipation unit disposed in the inverter housing, the heat dissipation unit contacting an outer surface of the capacitor and providing heat transfer communication between the capacitor and the inverter housing.

17. The apparatus of claim 16, wherein the heat dissipation unit extends along a longitudinal direction of the capacitor.

18. The apparatus of claim 16, wherein the outer surface of the capacitor is cylindrical.

19. The apparatus of claim 18, wherein the heat dissipation unit includes a contact surface contacting the outer surface of the capacitor, the contact surface having an arcuate cross-sectional shape.

20. The apparatus of claim 19, wherein the contact surface has a curvature equal to a curvature of the outer surface of the capacitor.

21. The apparatus of claim 16, wherein the heat dissipation unit is integrally formed with the inverter housing.

22. The apparatus of claim 16, wherein the heat dissipation unit includes: a heat dissipation body spaced from the capacitor; and a heat dissipation pad disposed between the heat dissipation body and the capacitor, the heat dissipation pad having a contact surface contacting the outer surface of the capacitor.

23. The apparatus of claim 22, wherein the heat dissipation pad is formed from a flexible material.

24. The apparatus of claim 22, wherein the heat dissipation pad has an arcuate cross-sectional shape and extends along a longitudinal direction of the capacitor, and wherein the heat dissipation body includes a heat dissipation pad receiving portion accommodating the heat dissipation pad.

25. The apparatus of claim 24, further comprising: a capacitor holder disposed in the inverter housing; and a printer circuit board disposed in the inverter housing, the capacitor holder having a pair of clamps clamping the outer surface of the capacitor and attaching the capacitor to the printed circuit board, and wherein the pair of clamps define a space therebetween, the heat dissipation pad disposed in the space, the pair of clamps militating against movement of the heat dissipation pad.

26. An inverter assembly comprising: an inverter controlling a rotation speed of a motor, the inverter including a capacitor; an inverter housing receiving the inverter therein; and a heat dissipation body disposed in the inverter housing and providing heat transfer communication between the capacitor and the inverter housing.

27. The inverter assembly of claim 26, wherein the heat dissipation body includes a contact surface having a shape corresponding to at least a portion of an outer surface of the capacitor.

28. The inverter assembly of claim 26, wherein the heat dissipation body is integrally formed with the inverter housing.

29. The inverter assembly of claim 26, wherein a heat dissipation pad is disposed between and in contact with the heat dissipation body and the capacitor.

30. The inverter assembly of claim 29, wherein the heat dissipation pad has an arcuate cross-sectional shape and extends along a longitudinal direction of the capacitor, and wherein the heat dissipation body includes a heat dissipation pad receiving portion accommodating the heat dissipation pad.

31. The apparatus of claim 30, wherein the inverter includes a capacitor holder and a printed circuit board, the capacitor holder attaching the capacitor to the printed circuit board, the capacitor holder having a pair of clamps clamping an outer surface of the capacitor, and wherein the pair of clamps define a space therebetween, the heat dissipation pad disposed in the space, the pair of clamps militating against rotational movement of the heat dissipation pad.

Description

DESCRIPTION OF DRAWINGS

[0022] FIG. 1 is a perspective view illustrating an electric compressor;

[0023] FIG. 2 is an exploded perspective view illustrating an inverter assembly of an electric compressor;

[0024] FIG. 3 is a perspective view illustrating an assembled state of a capacitor of FIG. 2;

[0025] FIG. 4 is a schematic assembled sectional view showing an inverter assembly of an electric compressor in accordance with a conventional technique;

[0026] FIG. 5 is a schematic sectional view illustrating an apparatus for cooling an inverter of an electric compressor in accordance with an embodiment of the present invention;

[0027] FIG. 6 is a plan view illustrating an inverter housing shown in FIG. 5;

[0028] FIG. 7 is a partial perspective view illustrating the inverter housing shown in FIG. 5; and

[0029] FIG. 8 is a schematic sectional view illustrating an apparatus for cooling an inverter of an electric compressor in accordance with another embodiment of the present invention.

MODE FOR INVENTION

[0030] Hereinafter, an apparatus for cooling an inverter of an electric compressor in accordance with an exemplary embodiment of the present invention will be described in detail with reference to the attached drawings.

[0031] Referring to FIGS. 5 to 7, the inverter cooling apparatus in accordance with the present embodiment of the present invention includes an inverter housing 20 which supports an inverter, and a heat dissipation unit 21 which is provided in contact with an outer circumferential surface of a capacitor 11.

[0032] The inverter is provided in the inverter housing 20 in a configuration in which various kinds of circuit elements including a switching element (IGBT; Insulated Gate Bipolar Transistor) and the capacitor 11 are mounted on a printed circuit board (PCB) 10.

[0033] The PCB 10 of the inverter is fixed to a portion of the inverter housing 20 by a screw. A capacitor holder 12 is provided on a portion of the PCB 10 while protruding toward the inverter housing 20.

[0034] The capacitor holder 12 includes a pair of clamps 13, which clamp the outer circumferential surface of the cylindrical capacitor 11.

[0035] The inverter housing 20 has an approximately ‘U’-shaped cross-sectional shape and receives therein electronic parts including the capacitor 11 that protrudes toward the portion of the PCB 10. The heat dissipation unit 21 is formed to protrude inward from a bottom surface of the inverter housing 20.

[0036] The heat dissipation unit 21 is formed on the bottom surface of the inverter housing 20 at a position below the capacitor 11 and has a contact surface 21a which comes into contact with the outer circumferential surface of the capacitor 11.

[0037] The contact surface 21a of the heat dissipation unit 21 has an arc-shaped cross-section with the same curvature as that of the outer circumferential surface of the cylindrical capacitor 11 and extends along a longitudinal direction of the capacitor 11. Therefore, the contact surface 21a comes into close contact with the outer circumferential surface of the capacitor 11 and thus is able to receive heat generated from the capacitor 11 and transfer it to the inverter housing 20.

[0038] In the present embodiment, the heat dissipation unit 21 is integrally formed with the inverter housing 20 so that heat generated from the capacitor 11 is directly transferred to the inverter housing 20. However, the heat dissipation unit 21 and the invert housing 20 may be separately provided from each other and coupled to come into contact with each other to allow heat transfer therebetween.

[0039] In the case where the heat dissipation unit 21 is integrally formed with the inverter housing 20, the same material is also used to form them. Consequently, the heat dissipation unit 21 has the same thermal conductivity as that of the inverter housing 20.

[0040] Meanwhile, because various vibrations are transmitted to the electric compressor during the driving of a vehicle, the inverter is faced with the problem of a reduction in the lifetime or deterioration in the performance due to continuous vibrations. Particularly, since the capacitor 11 is largest among the circuit elements, it is most vulnerable to vibrations.

[0041] Another embodiment of an inverter cooling device for an electric compressor having an additional vibration-proof function will be described with reference o FIG. 8.

[0042] The heat dissipation unit in accordance with the present embodiment includes a heat dissipation body 31 which is provided to be spaced apart from the capacitor 11 by a predetermined distance, and a heat dissipation pad 32 which is provided between the heat dissipation body 31 and the capacitor 11.

[0043] The heat dissipation body 31 is integrally formed with the inverter housing 20 so that heat transferred from the heat dissipation pad 32 is directly transferred to the inverter housing 20. A heat-dissipation-pad receiving portion 31a, on which the heat dissipation pad 32 is seated, is formed on an upper surface of the heat dissipation body 31.

[0044] The heat dissipation pad 32 has on an upper surface thereof a contact surface 32a, which comes into contact with the outer circumferential surface of the capacitor 11. A lower surface of the heat dissipation pad 32 comes into contact with an inner surface of the heat-dissipation-pad receiving portion 31a of the heat dissipation body 31. That is, as the cross-section of the heat dissipation pad 32 has an arc shape corresponding to the arc-shaped contact surface 32a, the upper surface of the heat dissipation pad 32 comes into close contact with the capacitor 11 while the lower surface thereof makes close contact with the heat dissipation body 31. As the arc-shaped cross-section of the heat dissipation pad 32 extends along the longitudinal direction of the capacitor 11, the heat dissipation pad 32 overall has a curved plate shape.

[0045] The heat dissipation pad 32 is provided in space between the heat dissipation body 31 and the capacitor 11. In a state in which the heat dissipation pad 32 is seated on the heat-dissipation-pad receiving portion 31a of the heat dissipation body 31, the upper contact surface 32a of the heat dissipation pad 32 comes into contact with the capacitor 11 while the lower surface thereof comes into contact with the heat dissipation body 31. Thus, the heat dissipation pad 32 receives heat from the capacitor 11 and transfers it to the heat dissipation body 31.

[0046] The heat dissipation pad 32 is disposed between the pair of clamps 13 of the capacitor holder 12. The pair of clamps 13 clamps the outer circumferential surface of the capacitor 11. Here, because the clamps 13 are disposed to be exposed outside the capacitor 11, both ends of the heat dissipation pad 32 are stopped by front ends of the pair of clamps 13 and thus prevented from moving. Thereby, the heat dissipation pad 32 can be prevented from being removed from space between the capacitor 11 and the heat dissipation body 31 without using a separate fixing means.

[0047] While the heat dissipation body 31 is made of the same hard thermal conductor as the material of the inverter housing 20, the heat dissipation pad 32 is made of soft flexible material different therefrom. As such, since the heat dissipation pad 32 has flexibility, it can absorb vibrations transmitted from the inverter housing 20 to the capacitor 11 or from the capacitor 11 to the inverter housing 20, thus providing the vibration-proof function of protecting the capacitor 11 from vibrations.

[0048] The heat dissipation pad 32 is made of soft material, but has high thermal conductivity. Therefore, both the vibration-proof performance and the heat dissipation performance can be satisfactory.

[0049] In the case of the conventional technique using capacitor-fixing silicon having a thermal conductivity of 0.17 W/m-K, when the motor was operated at 4000 rpm under conditions of an ambient temperature of 100° C., the surface of the capacitor 11 was approximately 114° C. However, in the case of the heat dissipation pad 32 having a thermal conductivity of 3.0 Wm-K, the surface temperature of the capacitor 11 was measured as being 85° C., which is reduced by 30° C., under the same conditions. In the case of typical capacitors, when the temperature is increased by 10° C., the lifetime is reduced to ½. Therefore, the present invention can obtain the effect of an increase in the lifetime by eight times.

[0050] Although the exemplary embodiments of the present invention have been disclosed for illustrative purposes, it will be appreciated that the present invention is not limited thereto, and those skilled in the art will appreciate that various modifications, additions, and substitutions are possible, without departing from the scope and spirit of the invention.

[0051] Accordingly, any and all modifications, variations or equivalent arrangements should be considered to be within the scope of the invention, and the detailed scope of the invention will be disclosed by the accompanying claims.