Electric compressor

Abstract

[Problem] To provide an electric compressor that makes it possible to prevent deformation of an attachment part provided to a housing and of the housing when the electric compressor is attached to an attachment object. [Solution] An electric compressor 1 comprises a housing 5 that accommodates a motor 2 and a compression mechanism 3, and a plurality of attachment parts 61 that are formed in the housing 5 and each have a through-hole 62. Each of a plurality of attachment bolts 20 is passed through the through-hole 62 of the corresponding attachment part 61 among the plurality of attachment parts 61 and is screwed into a female screw 12 formed in a fixed part 11 of a vehicle body 10, and the electric compressor 1 is thereby attached to the vehicle body 10. On the outer surface of at least one attachment part 61 of the plurality of attachment parts 61, a reinforcement rib 63 is formed so as to extend in the same direction as the through-hole 62 of said attachment part 61.

Description

Electric compressor

[0001] The present invention relates to an electric compressor to be attached to a predetermined attachment object.

[0002] Patent Document 1 describes an example of a conventional electric compressor. The electric compressor described in Patent Document 1 has a housing provided with a plurality of mounting feet (mounting portions), and holes through which bolts are inserted are formed in each of the plurality of mounting portions. The electric compressor described in Patent Document 1 is attached to a vehicle component (attachment object) by screwing a plurality of bolts through the holes of the plurality of mounting portions and into the vehicle component.

[0003] Japanese Patent Application Laid-Open No. 2020-67037

[0004] By the way, due to layout constraints or the like, a stress concentration portion (weak portion) or the like may be formed in or near the mounting portion provided in the housing of the electric compressor. In such a case, especially when the electric compressor is attached to the attachment object by bolts, the mounting portion, and thus the housing, may be deformed and problems may occur.

[0005] An object of the present invention is to provide an electric compressor that can prevent the mounting portion provided in the housing, and thus the housing, from being deformed when attached to an attachment object.

[0006] According to one aspect of the present invention, an electric compressor includes a motor that rotates a rotating shaft, a compression mechanism that is driven by the rotation of the rotating shaft to compress a refrigerant, a housing that houses the motor and the compression mechanism, and a plurality of mounting portions formed in the housing and each having a through hole. Each of the plurality of mounting bolts is configured to be attached to the attachment object by screwing through the through hole of the corresponding mounting portion among the plurality of mounting portions and into the attachment object. In the electric compressor, a reinforcing rib extending in the same direction as the through hole of the mounting portion is formed on an outer surface of at least one of the plurality of mounting portions.

[0007] According to the present invention, it is possible to provide an electric compressor having a structure that can prevent deformation of the mounting portion provided on the housing, and consequently the housing itself, when it is attached to an object to be mounted.

[0008] This is a diagram showing an electric compressor according to an embodiment. This is a diagram showing an electric compressor mounted on a vehicle body. This is a diagram showing an electric compressor mounted on a vehicle body. This is a diagram showing an electric compressor mounted on a vehicle body. This is a diagram showing the rear housing of the electric compressor. This is a diagram showing the rear housing of the electric compressor.

[0009] Hereinafter, embodiments of the present invention will be described based on the attached drawings.

[0010] Figure 1 is a side view showing an electric compressor 1 according to an embodiment of the present invention. The electric compressor 1 according to this embodiment is a so-called inverter-integrated electric compressor. The electric compressor 1 is mounted in a vehicle and constitutes part of the refrigerant circuit of a vehicle air conditioning system that air-conditions the interior of the vehicle. It is configured to inhale and compress refrigerant and discharge the compressed refrigerant.

[0011] Referring to Figure 1, the electric compressor 1 includes a motor 2, a compression mechanism 3, an inverter 4, and a housing 5.

[0012] Motor 2 is, for example, a three-phase synchronous motor. Motor 2 rotates its rotating shaft 2a by power supplied from the inverter 4. The rotating shaft 2a is also called the output shaft of motor 2, and in this embodiment, it extends in the front-to-back direction.

[0013] The compression mechanism 3 is a scroll-type compression mechanism, for example, including a fixed scroll and a movable scroll (neither of which are shown in the illustration). The compression mechanism 3 is configured to compress the refrigerant by being driven by the rotation of the rotating shaft 2a. The compression mechanism 3 is not limited to a scroll-type compression mechanism, and only needs to be driven by the rotation of the rotating shaft 2a, in other words, by the motor 2.

[0014] The inverter 4 includes a plurality of switching elements (not shown) and is configured to convert DC power from the vehicle's battery (not shown) into three-phase AC power, and to drive the motor 2 by supplying this three-phase AC power to the motor 2.

[0015] The housing 5 houses the motor 2, the compression mechanism 3, and the inverter 4. The housing 5 forms the outer casing of the electric compressor 1. The housing 5 may be made of a metal such as an aluminum alloy. In this embodiment, the housing 5 includes a front housing 51, a center housing 52, a rear housing 53, and an inverter cover 54.

[0016] The front housing 51 houses the motor 2 and the inverter 4. The front housing 51 extends in the front-rear direction and is formed as a hollow body with openings at its front and rear ends. Specifically, in this embodiment, the front housing 51 has a cylindrical body portion 511 having a generally circular cross-section and a non-circular body portion 512 having a non-circular cross-section. The non-circular body portion 512 is located in front of the cylindrical body portion 511, and the cross-section of the non-circular body portion 512 is larger than that of the cylindrical body portion 511. The internal space of the cylindrical body portion 511 and the internal space of the non-circular body portion 512 are separated by a partition wall (not shown). The motor 2 is housed in the cylindrical body portion 511, and the inverter 4 is housed in the non-circular body portion 512. The motor 2 is supplied with three-phase AC power from the inverter 4 via a power supply line (not shown) that extends through the partition wall.

[0017] The center housing 52 houses the compression mechanism 3. The center housing 52 is formed in a cylindrical shape corresponding to the cylindrical body portion 511 of the front housing 51 and is located on the rear side of the front housing 51.

[0018] The rear housing 53 is formed in a bottomed cylindrical shape corresponding to the center housing 52. The rear housing 53 is positioned behind the center housing 52 with its opening facing forward. Although not shown in the figure, the rear housing 53 is provided with a discharge chamber for discharging the refrigerant compressed by the compression mechanism 3, and a separation chamber for separating lubricating oil from the refrigerant.

[0019] The front housing 51, the center housing 52, and the rear housing 53 are fastened together by multiple bolts (hereinafter referred to as "fastening bolts") 55, with sealing material such as a gasket placed between them. The opening at the front end of the front housing 51 (the opening on the non-circular body portion 512 side) is closed by an inverter cover 54, and the inverter cover 54 is fixed to the front housing 51 by multiple cover fixing bolts 56.

[0020] The front housing 51 has an intake port 513 for drawing refrigerant into the housing 5. In this embodiment, the intake port 513 is located near the boundary between the cylindrical body portion 511 and the non-circular body portion 512 of the front housing 51, and is configured to draw refrigerant from the outside between the partition wall and the motor 2. The rear housing 53 also has a discharge port 531 for discharging refrigerant to the outside of the housing 5. In this embodiment, the discharge port 531 is located at the top of the rear housing 53, and is configured to discharge the refrigerant compressed by the compression mechanism 3 to the outside of the housing 5.

[0021] In the electric compressor 1, when the motor 2 is driven by the inverter 4, the motor 2 drives the compression mechanism 3 via the rotating shaft 2a. As a result, the electric compressor 1 draws in refrigerant from the intake port 513, compresses the drawn-in refrigerant with the compression mechanism 3, and discharges the compressed refrigerant from the discharge port 531.

[0022] The electric compressor 1 according to this embodiment is attached to a predetermined location on the vehicle body 10. Figures 2 to 4 show the electric compressor 1 attached to the vehicle body 10. Figure 2 is a side view corresponding to Figure 1, Figure 3 is a top view, and Figure 4 is a side view opposite to that of Figure 2.

[0023] Referring to Figures 2 to 4, the vehicle body 10 is provided with a plurality (four in this case) of fixing parts 11 for attaching the electric compressor 1. The plurality of fixing parts 11 are formed to rise from the vehicle body 10 and are spaced apart from each other. In this embodiment, each of the plurality of fixing parts 11 extends in the vertical direction, and the tip (upper end) of the fixing part 11 is a flat surface. In addition, each of the plurality of fixing parts 11 has a female thread 12 into which a bolt (hereinafter referred to as "mounting bolt") 20 used to attach the electric compressor 1 is screwed. The female thread 12 opens at the tip (upper end) of the fixing part 11 and extends in the axial direction (vertical direction) of the fixing part 11.

[0024] Referring to Figures 1 to 4, the housing 5 of the electric compressor 1 has a plurality of mounting portions 61 (the same number as the fixing portions 11 of the vehicle body 10, in this case four) for attaching the electric compressor 1 to the vehicle body 10. The plurality of mounting portions 61 are arranged to correspond to the plurality of fixing portions 11 provided on the vehicle body 10. In this embodiment, each of the plurality of mounting portions 61 extends in the vertical direction, and both ends of the mounting portion 61 (upper and lower ends) are flat surfaces. The upper end of the mounting portion 61 forms a contact surface that the seating surface of the head of the mounting bolt 20 contacts, and the lower end of the mounting portion 61 forms an opposing surface that faces the tip (upper end) of the fixing portion 11. In addition, each of the plurality of mounting portions 61 has a through hole 62 through which the shaft portion of the mounting bolt 20 passes. The through hole 62 extends in the longitudinal direction of the mounting portion 61, that is, in the vertical direction. The upper end of the through-hole 62 opens into the upper end of the mounting portion 61, and the lower end of the through-hole 62 opens into the lower end of the mounting portion 61. In other words, the through-hole 62 penetrates the mounting portion 61 in the vertical direction.

[0025] In this embodiment, some of the multiple mounting portions 61 (in this case, two mounting portions 61) are formed on the cylindrical body portion 511 of the front housing 51. These two mounting portions 61 are located radially outward of the cylindrical body portion 511 of the front housing 51. The remaining multiple mounting portions 61 (in this case, two mounting portions 61) are formed on the rear housing 53. These two mounting portions 61 are located radially outward of the rear housing 53.

[0026] The electric compressor 1 is attached to the vehicle body 10, for example, as follows.

[0027] First, the same number of mounting bolts 20 as the number of fixing parts 11 provided on the vehicle body 10 and the number of mounting parts 61 formed on the housing 5 of the electric compressor 1 (i.e., four) are prepared.

[0028] Next, the multiple mounting portions 61 formed on the housing 5 of the electric compressor 1 are positioned on the multiple fixing portions 11 provided on the vehicle body 10. That is, each of the multiple mounting portions 61 is positioned on the corresponding fixing portion 11 among the multiple fixing portions 11. At this time, intervening members 21 such as washers and / or vibration damping materials are placed between the fixing portion 11 (upper end) and the mounting portion 61 (lower end) as needed.

[0029] Then, each of the multiple mounting bolts 20 passes through the through hole 62 of the corresponding mounting part 61 among the multiple mounting parts 61 and is screwed into the female thread 12 formed in the corresponding fixing part 11 among the multiple fixing parts 11 provided on the vehicle body 10. In this way, the electric compressor 1 is attached to the vehicle body 10. In other words, the electric compressor 1 is fixed to the multiple fixing parts 11 provided on the vehicle body 10.

[0030] Figures 5 and 6 show the rear housing 53 that constitutes the housing 5 of the electric compressor 1. Figure 5 is a view of the rear housing 53 from the rear, and Figure 6 is a perspective view of the rear housing 53 from the rear.

[0031] In this embodiment, the outer surface of the rear housing 53 has two recesses 532 formed therein, which accommodate the heads of two of the multiple fastening bolts 55 that fasten the front housing 51, the center housing 52, and the rear housing 53. These two recesses 532 are each formed near the mounting portion 61, or more precisely, a part of them extends over the mounting portion 61. Therefore, there is a notch 533, in other words, a stress concentration area (weak point), in the mounting portion 61 and / or its vicinity formed on the rear housing 53. Consequently, when a high compressive force is applied to the mounting portion 61 when the electric compressor 1 is attached to the vehicle body 10 by multiple mounting bolts 20, there is a risk that the mounting portion 61 formed on the rear housing 53, and consequently the rear housing 53, may deform. If the rear housing 53 deforms, problems such as a decrease in the sealing performance between the center housing 52 and the rear housing 53 may occur.

[0032] Therefore, in this embodiment, the rear housing 53 employs the following configuration.

[0033] Reinforcement ribs 63 are formed on the outer surfaces of each of the two mounting portions 61 of the rear housing 53. The reinforcement ribs 63 protrude from the rearward-facing outer surface of the mounting portion 61, that is, they protrude to the rear. Furthermore, the reinforcement ribs 63 extend in the same direction (i.e., vertically) as the through holes 62 in the mounting portion 61 on which they are formed. This increases the strength of the mounting portion 61, especially its strength against compressive forces in the vertical direction, and prevents deformation of the two mounting portions 61 of the rear housing 53, and consequently the rear housing 53, when the electric compressor 1 is attached to the vehicle body 10 by the mounting bolts 20. In addition, the radial expansion of the rear housing 53 (i.e., the housing 5) due to the provision of the reinforcement ribs 63 can be suppressed. Here, the protruding height, width, and length of the reinforcement ribs 63 can be set as appropriate, but regarding the length, it is preferable that the reinforcement ribs 63 have a length of 1 / 2 or more of the length of the mounting portion 61 and / or the length of the through holes 62.

[0034] Furthermore, in each of the two mounting portions 61 of the rear housing 53, the center line 63A of the reinforcing rib 63 is located outside the center line 62A of the through hole 62 (= center line of the mounting bolt 20) when viewed from the rotation axis 2a (see Figure 5). Moreover, in this embodiment, in each mounting portion 61, when viewed from the rotation axis 2a, the center line 62A of the through hole 62 is located outside the notch portion 533, i.e., the stress concentration portion (weak portion), and the center line 63A of the reinforcing rib 63 is located outside the center line 62A of the through hole 62. With this configuration, it becomes possible to form reinforcing ribs 63 on the outer surface of the mounting portion 61 that can provide higher strength to the mounting portion 61, and deformation of the two mounting portions 61 of the rear housing 53, and consequently the rear housing 53, can be prevented more effectively.

[0035] In this embodiment, the vehicle body 10, front housing 51, center housing 52, and rear housing 53 correspond to the "mounting object," "first housing," "second housing," and "third housing" in the present invention.

[0036] The following describes some modified examples of the electric compressor 1 according to this embodiment.

[0037] In the above embodiment, the plurality of mounting portions 61 consist of a total of four mounting portions 61: two mounting portions 61 formed on the front housing 51 (the cylindrical body portion 511) and two mounting portions 61 formed on the rear housing 53. However, it is not limited to this. For example, the plurality of mounting portions 61 may consist of three or five mounting portions 61, or some of the plurality of mounting portions 61 may be formed on the center housing 52.

[0038] In the above-described embodiment, reinforcing ribs 63 are formed on the outer surfaces of the two mounting portions 61 formed in the rear housing 53. This is because, in the above-described embodiment, a recess 532 is formed in the rear housing 53 to accommodate the heads of the fastening bolts 55, and as a result, there is a notch 533 that can become a stress concentration area (weak area) in or near the two mounting portions 61 formed in the rear housing 53. However, it is not limited to this. For example, reinforcing ribs 63 may be formed on the outer surface of a mounting portion 61 in which a low-strength area is located nearby. Alternatively, reinforcing ribs 63 may be formed on the outer surface of a mounting portion 61 simply for the purpose of increasing the strength of the mounting portion 61 or for the purpose of increasing the strength of a mounting portion 61 that is weaker than other mounting portions 61. In other words, it is sufficient that reinforcing ribs 63 are formed on the outer surface of at least one of the multiple mounting portions 61 formed in the housing 5.

[0039] In the above embodiment, the reinforcing rib 63 is formed on the rearward-facing outer surface of the mounting portion 61 and protrudes rearward. However, it is not limited to this. If possible, the reinforcing rib 63 may be formed on the frontward-facing outer surface of the mounting portion 61 and protrude forward, or a first reinforcing rib protruding rearward and a second reinforcing rib protruding forward may be formed on the outer surface of the mounting portion 61.

[0040] Although embodiments and modifications of the present invention have been described above, the present invention is not limited to the embodiments and modifications described above, and further modifications are possible based on the technical concept of the present invention.

[0041] 1...Electric compressor, 2...Motor, 2a...Rotating shaft, 3...Compression mechanism, 4...Inverter, 5...Housing, 10...Body, 11...Fixing part, 12...Female thread, 20...Mounting bolt, 51...Front housing (first housing), 52...Center housing (second housing), 53...Rear housing (third housing), 54...Inverter cover, 55...Fastening bolt, 61...Mounting part, 62...Through hole, 62A...Center line of through hole, 63...Reinforcement rib, 63A...Center line of reinforcement rib, 513...Intake port, 531...Discharge port

Claims

1. An electric compressor comprising a motor for rotating a rotating shaft, a compression mechanism for compressing a refrigerant driven by the rotation of the rotating shaft, a housing for housing the motor and the compression mechanism, and a plurality of mounting parts formed in the housing, each having a through hole, wherein each of the plurality of mounting bolts is screwed into the object to be mounted by passing through the through hole of the corresponding mounting part among the plurality of mounting parts, wherein a reinforcing rib is formed on the outer surface of at least one of the plurality of mounting parts, extending in the same direction as the through hole of the mounting part.

2. The electric compressor according to claim 1, wherein the housing includes a first housing that houses the motor and has an intake port for drawing in refrigerant, a second housing that houses the compression mechanism, and a third housing that has a discharge port for discharging the refrigerant compressed by the compression mechanism, the third housing having recesses for accommodating the heads of fastening bolts that fasten the first housing, the second housing, and the third housing together, and at least one mounting portion is formed in the third housing.

3. The electric compressor according to claim 2, further comprising an inverter for driving the motor, wherein the first housing houses the motor and the inverter.

4. The electric compressor according to any one of claims 1 to 3, wherein the rotating shaft extends in the front-rear direction, the plurality of mounting portions and their through holes extend in the up-down direction, and in at least one mounting portion, the center line of the reinforcing rib is located outside the center line of the through hole of the mounting portion when viewed from the rotating shaft.

5. The electric compressor according to claim 4, wherein the reinforcing ribs protrude forward or backward.

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