Electric compressor

Abstract

An embodiment of the present invention provides an electric compressor. The electric compressor includes: a housing; a compression unit provided in the housing; a motor unit provided in the housing and driving the compression unit; and an inverter unit coupled to one side portion of the housing and controlling the motor unit, in which the inverter unit includes: an inverter body provided at one side portion of the housing; the circuit board is arranged in the inverter body; an inverter cover disposed on one side portion of the inverter body and covering the circuit board; and at least one fastening member passing through the inverter cover and the circuit board and fastened to the housing.

Description

Technical Field

[0001] The present disclosure relates to an electric compressor, and more particularly to an electric compressor capable of improving resonance noise of the inverter cover by reducing weight and increasing natural frequency by fastening an inverter cover and a circuit board together to a motor housing using a single fastening member, and pressing the circuit board toward the motor housing by a limiter welded to the circuit board, and having improved ground power and cooling performance of a switching element. Background Art

[0002] Generally, an air conditioning (A / C) device is installed in a vehicle for cooling or heating a passenger compartment. Such an air conditioning device includes a compressor that compresses a low-temperature and low-pressure gaseous refrigerant drawn from an evaporator into a high-temperature and high-pressure gaseous state and transmits it to a condenser.

[0003] Compressors applied to such vehicles include mechanical compressors driven by receiving driving force of an engine and electric compressors using a motor driven by electricity, and in recent years, the use of electric compressors has increased as electrification of vehicles has accelerated.

[0004] Meanwhile, examples of compressors include a reciprocating compressor that compresses refrigerant according to the reciprocating motion of a piston and a rotary compressor that compresses refrigerant while rotating. Reciprocating compressors include a crank compressor that transmits a driving force from a driving source to a plurality of pistons using a crank, and an inclined plate compressor that transmits a driving force from a driving source to a shaft on which an inclined plate is installed according to power transmission from the driving source, etc. Rotary compressors include a vane rotary compressor that utilizes a rotating shaft and vanes that rotate, and a scroll compressor that utilizes a movable scroll member and a fixed scroll member.

[0005] In addition, in the field of electric compressors, research and development of inverter-type compressors capable of changing the operating speed of a motor has been actively carried out. An example of a conventional inverter-type electric compressor is disclosed in Korean Patent No. 2022-0131164.

[0006] According to one example of a conventional electric compressor, the electric compressor 10 includes a housing 11, a compression portion 12, an electric motor 13, and an inverter portion 14. The housing 11 is made of an aluminum alloy, and has a motor housing 15 that accommodates the compression portion 12 and the electric motor 13, and an inverter housing that accommodates the inverter portion 14. A three-phase terminal portion 26 configured to supply three-phase AC power from the inverter portion 14 to the electric motor 13 passes through the inverter housing 18 and the motor housing 15 and is electrically connected to the circuit board 33.

[0007] In this case, screw holes 25 are formed on the outer wall portion 23 of the inverter case 18, and bolts (not shown) for fastening the inverter cover 24 are inserted into the screw holes 25. In addition, screw holes 28 are formed in the seating portion 27 of the inverter case 18, and bolts 50 for fastening the circuit board 33 are inserted into the screw holes 28.

[0008] Therefore, in the prior art patent, there is a problem that a large number of bolts are required because the bolts for fastening the inverter cover 24 and the inverter case 18 to each other and the bolts 50 for fastening the circuit board 33 and the inverter case 18 to each other and grounding the circuit board 33 and the inverter case 18 are separately configured, and thus the weight increases.

[0009] In addition, the inverter cover 24 is formed to be long, and the fastening bolts are provided only in the outer region and cannot be provided in the center, so the natural frequency is low, and noise caused by resonance of the inverter cover is generated. Summary of the invention

[0010] Technical issues

[0011] An object of the present disclosure is to provide an electric compressor capable of improving the resonance noise of the inverter cover by reducing weight and increasing natural frequency by fastening an inverter cover and a circuit board together to a motor housing using a single fastening member, and pressing the circuit board toward the motor housing by a limiter welded to the circuit board, and having improved ground power and cooling performance of a switching element.

[0012] The technical problems to be achieved by the present disclosure are not limited to the above-mentioned technical problems, and a person of ordinary skill in the art to which the present disclosure belongs will clearly understand other technical problems not mentioned through the following description.

[0013] Technical Solutions

[0014] One embodiment is an electric compressor, which includes: a shell; a compression part, which is arranged in the shell; a motor part, which is arranged in the shell and is configured to drive the compression part; and an inverter part, which is connected to one side of the shell and is configured to control the motor part. The inverter part may include: an inverter body, which is arranged on one side of the shell; a circuit board, which is seated in the inverter body; an inverter cover, which is arranged on one side of the inverter body and covers the circuit board; and at least one or more fastening members, which pass through the inverter cover and the circuit board to be fastened to the shell.

[0015] According to an embodiment, the fastening member may penetrate the inverter cover, the circuit board, and the inverter body to be fastened to the case.

[0016] According to an embodiment, the electric compressor may further include at least one or more limiters that contact the circuit board and allow the fastening member to pass through an inside of the limiter.

[0017] According to an embodiment, when the fastening member may be fastened to the case, the restrictor may be in contact with the inverter cover.

[0018] According to an embodiment, the limiter may press the circuit board toward the case by a fastening force of the fastening member.

[0019] According to an embodiment, the limiter may be soldered and surface-mounted to a surface of the circuit board facing the inverter cover.

[0020] According to an embodiment, the restrictor may pass through the circuit board and may be welded to the surface facing the housing via a flange.

[0021] According to an embodiment, the fastening member may be provided in plurality, and at least one of the plurality of fastening members may be provided closer to the centerline than to the tip end with respect to a longitudinal direction in which the length of the inverter cover is longest.

[0022] According to an embodiment, the fastening members may be provided in plurality, and the plurality of fastening members may be provided more on a side where the switching element connected to the circuit board is provided based on a longitudinal center line, wherein the longitudinal center line is perpendicular to the longitudinal direction and passes through the center of the inverter cover, and the length of the inverter cover is the longest in the longitudinal direction.

[0023] According to an embodiment, a plurality of fastening members disposed on one side on which the switching element is disposed based on a longitudinal center line of the inverter cover may be disposed in one line.

[0024] According to an embodiment, the inverter cover may include a plurality of guide protrusions, and a plurality of guide holes into which the plurality of guide protrusions are inserted may be formed on the circuit board.

[0025] According to an embodiment, a stepped surface protruding toward the circuit board may be formed around each of the plurality of guide protrusions.

[0026] According to an embodiment, at least some of the plurality of guide protrusions may be heat-fused.

[0027] According to an embodiment, a diameter of the guide hole may be smaller than a diameter of a fastening hole formed on the circuit board to allow the fastening member to pass therethrough.

[0028] According to an embodiment, the inverter body may be made of a plastic material.

[0029] Beneficial effects

[0030] According to the present disclosure, since the number of bolts can be reduced by fastening the inverter cover and the circuit board together to the motor case using a single fastening member, the weight can be reduced, and since the distance between the fastening members is reduced, the resonance noise of the inverter cover can be improved by increasing the natural frequency.

[0031] In addition, the limiter soldered to the circuit board can function as a ground while electrically connecting the inverter cover, the circuit board, and the motor housing, thereby improving the grounding power.

[0032] In addition, since the restrictor can press the circuit board, in particular the switching element, toward the motor housing by the fastening force of the fastening member, the cooling performance of the switching element can be improved.

[0033] In addition, since the inverter body and the circuit board respectively include guide protrusions and guide holes configured to engage with each other, the inverter body and the circuit board can be aligned before the inverter body and the circuit board are fastened using fastening components, and the circuit board can be more stably seated on the inverter body by hot melting.

[0034] The effects of the embodiments of the present disclosure are not limited to the above-described effects, and it should be understood that the effects of the present disclosure include all effects that can be inferred from the configuration of the present invention described in the detailed description of the present invention or the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is an exploded perspective view of an electric compressor according to an embodiment of the present disclosure,

[0036] Figure 2 It is a partial diagram Figure 1 A cross-sectional view of a state where the electric compressor is connected.

[0037] Figure 3 It is a graphic Figure 1 A front view of a state in which the electric compressor is connected and the inverter cover is separated.

[0038] Figure 4 yes Figure 1 Front view of the circuit board with the circuit board separated.

[0039] Figure 5 yes Figure 1 Front view of the inverter body with it separated.

[0040] Figure 6 yes Figure 5 Rear view showing the circuit board installed.

[0041] Figure 7 It is a perspective view showing a state where the limiter is surface-mounted to a circuit board.

[0042] Figure 8 is a cross-sectional view illustrating a state in which the restrictor passes through a circuit board and is soldered.

[0043] Figure 9a and Figure 9b They are shown separately Figure 5 A perspective view of part A and part B.

[0044] Fig.10a and Fig.10b It is along Figure 3 The cross-sectional view taken along line XX illustrates the state of the guide protrusion before and after hot melting. DETAILED DESCRIPTION

[0045] Hereinafter, exemplary embodiments of the electric compressor of the present disclosure will be described with reference to the accompanying drawings.

[0046] In addition, terms used herein are defined in consideration of functions in the present disclosure and may vary according to user or operator's intention or practice, and the following embodiments do not limit the scope of the present disclosure but are merely examples of components presented in the claims.

[0047] In addition, for the sake of clarity, parts not related to the description are omitted, and the same or similar parts are assigned the same reference numerals throughout the specification. It should also be understood that, unless otherwise defined, the terms "include" and "comprising" used herein specify the presence of the stated elements, but do not exclude the presence or addition of other elements.

[0048] First, refer to Figure 1 The configuration of the electric compressor 1 according to the embodiment of the present disclosure will be briefly described.

[0049] The electric compressor of the present disclosure includes a housing 10 , a motor portion, a compression portion, and an inverter portion 20 .

[0050] The housing 10 forms the exterior of the electric compressor 1 , and in the present embodiment, the housing 10 is composed of a front housing (motor housing) 12 and a rear housing 14 .

[0051] The motor part is disposed in the front housing 12 and provides power to the compression part for compressing the refrigerant. Although not shown, the motor part may include: a rotor coupled to a rotating shaft rotatably mounted at the center of the front housing 12; and a stator fixed to the front housing 12 and disposed radially outside the rotor. In addition, the stator may include a stator core and a coil wound around the stator core.

[0052] The compression part is disposed in the rear housing 14, and although not shown, the compression part may include a movable scroll member coupled to the rotating shaft through an eccentric bushing and a fixed scroll member forming a compression chamber, and the refrigerant is compressed in the compression chamber together with the movable scroll member. Therefore, since the compression part is connected to the motor part through the rotating shaft, the rotational force generated by the motor part can be transmitted to the movable scroll member of the compression part through the rotating shaft. However, it is not limited thereto, and other types of compression parts may obviously be used.

[0053] The inverter part 20 is coupled to one side of the housing 10, which is the opposite side of the compression part relative to the motor part. The inverter part 20 is electrically connected to the motor part, supplies power to the motor part, and controls the operation of the motor part by means of power and control signals transmitted from the outside. Specifically, the stator forms an electromagnetic field by power applied from the inverter part 20, and generates a rotational force for driving the compression part when the rotor is rotated by the electromagnetic field formed by the stator.

[0054] At this time, the motor part and the inverter part 20 can be electrically connected to each other through a connecting pin. Since a three-phase motor is used in the present embodiment, three connecting pins connected to the three phases are provided respectively so that three-phase power is supplied from the inverter part 20 to the motor part. The three connecting pins are electrically connected to the three-phase coils of the stator, respectively, pass through the front housing 12 and protrude toward the inside of the inverter part 20. Each of the connecting pins protruding toward the inside of the inverter part 20 passes through the circuit board 200 of the inverter part and is electrically connected to the circuit board 200. To this end, a through hole can be formed on one side of the front housing 12 and on the circuit board 200 so as to allow the connecting pin to pass through the through hole.

[0055] In the following, reference will be made to Figures 1 to 7 The inverter part 20 is described in detail. The inverter part 20 may include an inverter body 100 , a circuit board 200 , an inverter cover 300 , a fastening member, and a limiter 500 .

[0056] The inverter body 100 is disposed on one side of the front housing 12, and a circuit board 200 to which a switching element is connected is seated on the inverter body 100. The inverter body 100 is made of plastic resin in order to reduce costs and make the inverter body 100 lighter. According to an embodiment, even if the inverter body 100 is made of plastic resin, an electromagnetic interference shielding member (not shown) made of metal may be provided on the inside or outside of the inverter body 100 to allow shielding of interference of electromagnetic waves.

[0057] The inverter cover 300 is disposed on one side of the inverter body 100 and covers the circuit board 200. In the present embodiment, the inverter cover 300 is formed in the same shape as the inverter body 100 and completely covers one side of the inverter body 100.

[0058] In this case, at least one or more fastening members pass through the inverter cover 300, the circuit board 200, and the inverter body 100 and are fastened to the front housing 12. In the present embodiment, a description will be provided based on that the fastening member is a fastening bolt 400. That is, the inverter cover 300 and the circuit board 200 are coupled to the front housing 12 together by a single type of fastening bolt 400, rather than falling into a situation where the inverter cover 300 and the circuit board 200 are coupled to the front housing 12 by different types of fastening bolts, respectively. For this reason, the first to third fastening holes 120, 220, and 320 through which the fastening bolts 400 pass are illustrated on the inverter body 100, the circuit board 200, and the inverter cover 300, respectively. Therefore, since the number of bolts can be reduced by using a single type of fastening bolt 400 to fasten the inverter cover 300 and the circuit board 200 to the front housing 12 together, the weight can be reduced. In the present embodiment, a plurality of fastening members are provided, and five fastening bolts 400 a to 400 e are illustrated as an example, however, the present embodiment is not limited thereto.

[0059] It is desirable that at least one of the plurality of fastening bolts 400 is disposed closer to the center line CL than to the tip end with respect to the longitudinal direction in which the length of the inverter cover 300 is longest. Figure 3 As shown in the figure, in the present embodiment, one fastening bolt 400b is disposed closer to the center line CL in the longitudinal direction of the inverter cover 300. Therefore, the central portion of the inverter cover 300 can be supported, and therefore, compared with a conventional structure in which fastening bolts for fastening the inverter cover are disposed only on the outer side of the inverter cover 300, the distance between the fastening bolts 400 is reduced, thereby improving the resonance noise of the inverter cover 300 by increasing the natural frequency.

[0060] The plurality of limiters 500 contact the circuit board 200, and the plurality of fastening bolts 400 pass through each of the plurality of limiters 500. In the present embodiment, the plurality of limiters 500 are provided corresponding to the plurality of fastening bolts 400. The limiters 500 are provided between the inverter cover 300 and the circuit board 200, and Figure 2As shown, when the fastening bolt 400 is fastened to the front housing 12, the limiter 500 contacts the inverter cover 300. The limiter 500 is formed to have a cylindrical shape with a hollow hole, and the fastening bolt 400 passes through the inside of the limiter 500, so the limiter 500 can be used as a guide for the fastening bolt 400. The limiter 500 can be formed of a metal material.

[0061] like Figure 7 As shown, in the present embodiment, the limiter 500 is welded and surface-mounted to the surface of the circuit board 200 facing the inverter cover 300. Therefore, when the fastening bolt 400 is fastened, the inverter cover 300 contacts the limiter 500 and generates a force that presses the limiter 500 toward the housing 10 side. Therefore, the limiter 500 can press the circuit board 200 toward the housing 10 side by the fastening force of the fastening bolt 400.

[0062] In particular, it is desirable that the fastening bolts 400 are more disposed on the side where the switch element 204 connected to the circuit board 200 is disposed based on the longitudinal center line CL which is perpendicular to the longitudinal direction and passes through the center of the inverter cover 300 in which the length of the inverter cover 300 is the longest. Figure 6 As shown in the figure, in the present embodiment, the capacitor 202 and the switching element 204 are arranged on the lower side based on the longitudinal center line CL of the inverter cover 300, and therefore, it can be seen that the number of the fastening bolts 400 arranged on the lower side is greater than the number of the fastening bolts 400 arranged on the upper side based on the longitudinal center line CL of the inverter cover 300. In more detail, as Figure 3 As illustrated, two fastening bolts 400 a and 400 b are disposed on the upper side, and three fastening bolts 400 c , 400 d , and 400 e are disposed on the lower side based on the longitudinal center line CL of the inverter cover 300 .

[0063] At this time, the three fastening bolts 400c, 400d and 400e provided on the side where the switch element 204 is provided can be provided in a line based on the longitudinal center line CL of the inverter cover 300. With this configuration, all surfaces of the switch element 204 can be in close contact with the front housing 12, so that the cooling of the switch element can be effectively performed.

[0064] As described above, the limiter 500 welded to the circuit board 200 electrically connects the inverter cover 300, the circuit board 200, and the front housing 12 to each other, and can be used as a ground in its function, so that the grounding power can be improved. In addition, since the limiter 500 can press the circuit board 200, especially the switching element 204, toward the housing 10 side by the tightening force of the tightening bolt 400, the cooling performance of the switching element can be improved.

[0065] However, the embodiment is not limited thereto, and as Figure 8 As shown, the limiter 1500 may pass through the circuit board 200 and may be welded to the surface facing the housing 10 through the flange 1520. In this case, since the fastening bolt 400 and the limiter 1500 must pass through the circuit board 200 together, the size of the second fastening hole 220 of the circuit board may become larger than the size of the second fastening hole 220 used in the case where the limiter is surface mounted.

[0066] According to the implementation mode, Figure 4 and Figure 5 As shown, the inverter body 100 may include a plurality of guide protrusions 140, and a plurality of guide holes 240 may be formed on the circuit board 200, and the plurality of guide protrusions 140 are respectively inserted into the plurality of guide holes 240. In the present embodiment, nine guide protrusions 140 and nine guide holes 240 are formed, but the present embodiment is not limited thereto. Since the inverter body 100 and the circuit board 200 include the guide protrusions 140 and the guide holes 240 configured to engage with each other, the inverter body 100 and the circuit board 200 may be aligned with each other before the inverter body 100 and the circuit board 200 are fastened using a fastening member.

[0067] In order to ensure a space for arranging components on the circuit board 200, it is desirable that the diameter of the guide hole 240 is smaller than the diameter of the second fastening hole 220 through which the fastening bolt 400 passes. A plurality of guide holes 240 are disposed closer to the second fastening hole 220, or are disposed on an outer region of the circuit board 200. The guide holes 240 may be formed as through holes passing through the circuit board, or as cutout holes cut from the outer circumference of the circuit board to the inside.

[0068] Around each of the guide protrusions 140, a stepped surface 160 protruding toward the circuit board 200 may be formed. Figure 9a and Figure 9b , a rectangular or circular stepped surface 160 is illustrated surrounding the guide protrusion 140. With this configuration, the circuit board 200 can be prevented from being lifted due to interference with the inverter body 100, and helps the circuit board 200 to be stably seated on the inverter body 100.

[0069] At least some of the plurality of guide protrusions 140 may be formed on a flange 130 protruding inward from the periphery of the inverter body 100. The flange 130 forms a surface having the same height as that of the stepped surface 160, and thus, the flange 130 may support the circuit board 200 on a plane.

[0070] At this time, at least one guide protrusion among the plurality of guide protrusions 140 may be heat-fused. The inverter body 100 is made of a plastic material, and thus heat-fused is possible. Fig.10aand Fig.10b The diagram shows the states before and after the guide protrusion 140 is heat-melted. Therefore, since the guide protrusion 140 is heat-melted and fixed on the guide hole 240, the circuit board 200 can be seated on the inverter body 100 more stably.

[0071] The present disclosure is not limited to the above specific embodiments and descriptions, and those skilled in the art may make various modifications without departing from the gist of the present disclosure claimed in the claims. Such modifications are within the scope of protection of the present disclosure.

[0072] Industrial Applicability

[0073] The present invention relates to an electric compressor, and more particularly to an electric compressor capable of improving resonance noise of the inverter cover by reducing weight and increasing natural frequency by fastening an inverter cover and a circuit board together to a motor housing using a single fastening member, and pressing the circuit board toward the motor housing by a limiter welded to the circuit board, and having improved grounding power and cooling performance of a switching element.

Claims

1. An electric compressor, comprising: case; a compression portion disposed in the housing; a motor portion disposed in the housing and configured to drive the compression portion; as well as an inverter portion coupled to one side of the housing and configured to control the motor portion, Wherein, the inverter part includes: An inverter body, the inverter body being arranged on a side portion of the housing; A circuit board, the circuit board is seated in the inverter body; an inverter cover disposed on one side of the inverter body and covering the circuit board; and At least one or more fastening members pass through the inverter cover and the circuit board to be fastened to the housing.

2. The electric compressor according to claim 1, in, The fastening member passes through the inverter cover, the circuit board, and the inverter body to be fastened to the housing.

3. The electric compressor according to claim 1, further comprising: At least one or more limiters that contact the circuit board and allow the fastening member to pass through an interior of the limiter.

4. The electric compressor according to claim 3, in, When the fastening member is fastened to the housing, the restrictor comes into contact with the inverter cover.

5. The electric compressor according to claim 4, in, The restrictor presses the circuit board toward the housing by a fastening force of the fastening member.

6. The electric compressor according to claim 4, in, The limiter is soldered and surface-mounted to a surface of the circuit board facing the inverter cover.

7. The electric compressor according to claim 4, in, The restrictor passes through the circuit board and is welded to a surface facing the housing through a flange.

8. The electric compressor according to claim 1, in, The fastening member is provided in plural, and at least one of the plural fastening members is provided closer to the center line than to the tip end with respect to the longitudinal direction in which the length of the inverter cover is longest.

9. The electric compressor according to claim 5, in, The fastening members are provided in plurality, and the plurality of fastening members are provided more on a side where a switch element connected to the circuit board is provided based on a longitudinal center line, wherein the longitudinal center line is perpendicular to the longitudinal direction and passes through the center of the inverter cover, and the length of the inverter cover is the longest in the longitudinal direction.

10. The electric compressor according to claim 9, in, The plurality of fastening members disposed on the side where the switching element is disposed based on the longitudinal center line of the inverter cover are disposed in one line.

11. The electric compressor according to claim 1, in, The inverter cover includes a plurality of guide protrusions, and Wherein, a plurality of guide holes are formed on the circuit board, and a plurality of guide protrusions are inserted into the guide holes.

12. The electric compressor according to claim 11, in, A stepped surface protruding toward the circuit board is formed around each of the plurality of guide protrusions.

13. The electric compressor according to claim 11, in, At least some of the plurality of guide protrusions are heat-fused.

14. The electric compressor according to claim 11, in, The guide hole has a diameter smaller than a diameter of a fastening hole formed on the circuit board to allow the fastening member to pass therethrough.

15. The electric compressor according to claim 1, in, The inverter body is made of plastic material.

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