Electric compressor

Abstract

The invention provides an electric compressor capable of suppressing deformation of a stator housing for fixing a stator through sintering and embedding and realizing light weight. The electric compressor is provided with a cylindrical stator housing (7) having an opening at one end, and a rear housing joined to the opening of the stator housing with a gasket interposed therebetween, the stator of the electric motor is housed from the opening of the stator housing, and the stator is fixed to the inner surface of the stator housing by burn-fitting. This electric compressor is provided with: a plurality of burn-in affixing surfaces (42) which are formed on the inner surface of a stator housing (7) and which affix a stator; a gasket sealing surface (7B) which is formed on the opening end surface of the stator housing (7) and in which a gasket is disposed; and a plurality of ribs (49) formed on the opening side of the outer surface of the stator housing corresponding to the burn-in fixing surface.

Description

Technical Field

[0001] The present invention relates to an electric compressor in which a stator of a motor is fixed in a stator housing by burn-fitting. Background Art

[0002] In the past, this electric compression mechanism became a compression mechanism that was provided with a motor and driven by this motor in a stator housing. In this case, an end opening of the stator housing, the motor was arranged in the stator housing from this opening, and the opening of the stator housing was sealed by engaging with the rear housing.

[0003] In addition, the stator of the motor is fixed to the inner surface of the stator housing by burn-in. Therefore, there is a risk of deterioration of sealing performance due to deformation of the gasket sealing surface joined to the rear housing, so conventionally, a plurality of ribs are formed on the outer peripheral surface of the stator housing to increase the strength of the stator housing, thereby suppressing deformation of the gasket sealing surface (for example, see Patent Document 1).

[0004] Patent Document 1: Japanese Patent No. 6700674

[0005] However, if a large number of ribs are formed as in the conventional method, the weight of the stator case increases, and when the electric compressor is used, for example, for an air conditioner of an electric vehicle, there is a problem of reduced cruising range. Summary of the invention

[0006] The present invention has been made to solve the above-mentioned conventional technical problems, and an object of the present invention is to provide an electric compressor which can achieve weight reduction while suppressing deformation of a stator housing to which a stator is fixed by shrink-fitting.

[0007] The electric compressor of the present invention includes a cylindrical stator shell with an opening at one end, and a rear shell connected to the opening of the stator shell through a gasket. The stator of the motor is accommodated through the opening of the stator shell, and the stator is fixed to the inner surface of the stator shell by burn-in. The rear shell includes: a plurality of burn-in fixing surfaces formed on the inner surface of the stator shell to fix the stator; a gasket sealing surface formed on the open end surface of the stator shell to be provided with a gasket; and a plurality of ribs formed on the open side of the outer surface of the stator shell corresponding to the burn-in fixing surfaces.

[0008] The electric compressor of the invention of mode 2 includes a center plate based on the above invention. The center plate is accommodated in the stator housing and is located on the opening side of the motor. The inner surface of the stator housing on the opening side of the burn-in fixing surface is formed with a fitting surface for fitting the center plate.

[0009] The electric compressor according to the third aspect of the invention is the one described above, wherein a scroll compression mechanism is provided in a space formed by the center plate and the rear housing.

[0010] The electric compressor of the invention of mode 4 includes, based on the above invention, a refrigerant suction port formed at the other end of the stator housing; and a refrigerant channel formed between each embedded fixing surface to connect the suction port with the refrigerant suction part of the scroll compression mechanism.

[0011] According to the present invention, the electric compressor includes a cylindrical stator housing with an opening at one end, and a rear housing joined to the opening of the stator housing via a gasket, and the stator of the motor is accommodated through the opening of the stator housing, and the stator is fixed to the inner surface of the stator housing by burn-in, wherein a plurality of burn-in fixing surfaces for fixing the stator are formed on the inner surface of the stator housing, and a gasket sealing surface for arranging the gasket is formed on the open end surface of the stator housing, and a plurality of ribs are formed on the open side of the outer surface of the stator housing corresponding to the burn-in fixing surfaces, so that the strength of the open side of the stator housing, which is most easily deformed when the stator is burn-in, can be improved by the ribs.

[0012] Thus, deformation of the gasket sealing surface with the rear housing can be suppressed, and an increase in the weight of the stator housing due to the formation of the ribs can be suppressed, thereby achieving weight reduction of the electric compressor.

[0013] In particular, in an electric compressor including a center plate and a scroll compression mechanism such as in forms 2 to 4, the present invention is extremely suitable because it can reduce weight while suppressing deformation of the center plate fitting surface of the stator housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic cross-sectional view of an electric compressor according to an embodiment of the present invention. Figure 2 yes Figure 1 A three-dimensional view of a stator housing of an electric compressor. Figure 3 yes Figure 1 Another perspective view of the stator housing of an electric compressor. Figure 4 Viewed from the opening side Figure 1 Diagram of the stator housing of an electric compressor. DETAILED DESCRIPTION

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 It is a schematic cross-sectional view of an electric compressor 1 according to one embodiment of the present invention.

[0016] The electric compressor 1 of the embodiment is a so-called horizontal inverter-integrated scroll electric compressor, which is used, for example, in the refrigerant circuit of an air-conditioning device for an electric vehicle, and sucks in a refrigerant as a working fluid of the air-conditioning device, compresses the refrigerant and discharges it to a discharge pipe. The electric compressor 1 includes: a three-phase electric motor 2 as a motor in the present invention; an inverter 3 for operating the electric motor 2; and a scroll compression mechanism 4 as a compression mechanism driven by the electric motor 2.

[0017] The electric compressor 1 of the embodiment includes: a cylindrical stator housing 7, which accommodates an electric motor 2 and a center plate 6 on the inside; an inverter box 8, which is installed on the end wall 7A on the other end side of the stator housing 7 and accommodates the inverter 3 on the inside; and a rear shell 9, which is installed on the stator housing 7 in a manner to block the opening on one end side of the stator housing 7.

[0018] The stator housing 7 , the inverter case 8 , and the rear housing 9 are all made of metal (aluminum in the embodiment), and are integrally joined to form a housing 11 of the electric compressor 1 of the embodiment.

[0019] A motor chamber 12 for accommodating the electric motor 2 is formed in the stator housing 7. One end of the motor chamber 12 is open, and after the electric motor 2 is accommodated in the motor chamber 12 through the opening, the center plate 6 is accommodated through the same opening. In addition, the other end surface of the motor chamber 12 is basically closed by the end wall 7A of the stator housing 7. A sub-bearing 16 is mounted on the inner surface (motor chamber 12 side) of the end wall 7A, and the sub-bearing 16 is used to support the other end of the drive shaft 14 of the electric motor 2 so that it can rotate.

[0020] The center plate 6 has an opening on the side opposite to the electric motor 2 (one end side), and after accommodating the movable scroll 22 of the scroll compression mechanism 4, the opening is closed by fixing the rear housing 9 to the opening of the stator housing 7, and the rear housing 9 has the fixed scroll 21 of the scroll compression mechanism 4 fixed thereto. Thus, the scroll compression mechanism 4 is located in the space formed by the center plate 6 and the rear housing 9.

[0021] At this time, the open end surface of one end of the stator housing 7 becomes the gasket sealing surface 7B ( Figure 2 ), an annular gasket 41 for sealing the gap between the stator housing 7 and the rear housing 9 is provided on the gasket sealing surface 7B. And, the rear housing 9 is fixed to the opening end surface 7B of the stator housing 7 by bolts via the gasket 41.

[0022] In addition, a through hole 17 is opened in the center plate 6 for passing one end of the driving shaft 14 of the electric motor 2, and a main bearing 18 is installed on the side of the scroll compression mechanism 4 of the through hole 17 and in the center plate 6. The main bearing 18 supports one end of the driving shaft 14 on the side of the scroll compression mechanism 4 so that it can rotate.

[0023] The electric motor 2 is composed of a stator 25, on which a coil is wound, and a rotor 23 that rotates inside the stator 25. The stator 25 is fixed to the inner side of the peripheral wall of the stator housing 7 by shrink-fitting. The inverter 3 converts a direct current from a battery (not shown) of the vehicle into a three-phase alternating current and supplies the three-phase alternating current to the coil of the stator 25 of the electric motor 2, thereby driving the rotor 23 to rotate. The drive shaft 14 is fixed to the rotor 23.

[0024] In addition, a suction port 30 is formed at the other end of the stator housing 7. The refrigerant sucked from the suction port 30 flows into the center plate 6 after passing through the motor chamber 12 of the stator housing 7, and is sucked into the suction portion 37 outside the scroll compression mechanism 4. Thus, the electric motor 2 is cooled by the sucked refrigerant. In addition, the refrigerant compressed by the scroll compression mechanism 4 is discharged from the discharge chamber 27 to the discharge piping of the refrigerant circuit (not shown) outside the housing 11 through the discharge port 20 formed in the rear housing 9.

[0025] The scroll compression mechanism 4 is composed of the aforementioned fixed scroll 21 and movable scroll 22. The fixed scroll 21 is integrally provided with a disc-shaped cover plate 23, and a spiral volute (wrap) 24 which is vertically arranged on the surface (one surface) of the cover plate 23 and is formed of an involute shape or a curve similar to the involute shape, and the surface of the cover plate 23 on which the volute 24 is vertically arranged is fixed to the rear housing 9 as the center plate 6 side. A discharge hole 26 is formed in the center of the cover plate 23 of the fixed scroll 21, and the discharge hole 26 is connected to the discharge chamber 27 in the rear housing 9. In the figure, 28 is a discharge valve, and the discharge valve 28 is arranged at the opening of the discharge hole 26 on the back side (the other side) of the cover plate 23.

[0026] The movable scroll 22 is a scroll that revolves relative to the fixed scroll 21, and is integrally provided with a disc-shaped cover plate 31, a spiral volute 32 in an involute shape or a spiral volute formed by a curve similar to the involute shape and arranged upright on the surface (one surface) of the cover plate 31, and a boss 33 formed protrudingly at the center of the back surface (the other surface) of the cover plate 31. The movable scroll 22 is arranged in such a manner that the volute 32 and the volute 24 of the fixed scroll 21 are opposed to each other and meshed with each other, with the protruding direction of the volute 32 being the fixed scroll 21 side, and a pressure chamber 34 is formed between each volute 24, 32.

[0027] That is, the volute 32 of the movable scroll 22 is opposed to the volute 24 of the fixed scroll 21, and meshes with each other in a manner that the top end of the volute 32 contacts the surface of the cover plate 23 and the top end of the volute 24 contacts the surface of the cover plate 31, and an eccentric portion 36 is fitted in the boss 33 of the movable scroll 22, and the eccentric portion 36 is eccentrically arranged from the axis at one end of the drive shaft 14. Moreover, if the drive shaft 14 rotates together with the rotor 23 of the electric motor 2, the movable scroll 22 does not rotate on its own, but revolves relative to the fixed scroll 21.

[0028] Since the movable scroll 22 revolves eccentrically relative to the fixed scroll 21, the eccentric directions and contact positions of the volutes 24 and 32 move while rotating, and the pressure chamber 34 that sucks the refrigerant from the suction portion 37 on the outside gradually shrinks while moving inward. As a result, the refrigerant is continuously compressed and finally discharged from the discharge hole 26 in the center through the discharge valve 28 to the discharge chamber 27.

[0029] exist Figure 1 38 is a circular thrust plate. The thrust plate 38 is used to divide the back pressure chamber 39 formed between the back side of the cover plate 31 of the movable scroll 22 and the center plate 6 and the suction portion 37 on the outside of the scroll compression mechanism 4, and is located on the outside of the boss 33 and between the center plate 6 and the movable scroll 22.

[0030] In addition, reference numeral 48 denotes a centrifugal oil separator installed in the discharge chamber 27 of the rear housing 9 (casing 11). The oil separator 48 separates the lubricating oil mixed in the refrigerant discharged from the scroll compression mechanism 4 to the discharge chamber 27, and the refrigerant is discharged toward the discharge port 20 to the discharge pipe.

[0031] An oil storage chamber 44 is formed in the rear housing 9 below the oil separator 48, and the oil separated from the refrigerant by the oil separator 48 flows into the oil storage chamber 44 from the lower end of the oil separator 48. In the figure, 43 is a back pressure passage formed from the rear housing 9 to the center plate 6, and has a throttle hole 50. The discharge pressure adjusted by the throttle hole 50 of the back pressure passage 43 is configured to be supplied to the back pressure chamber 39 together with the oil in the oil storage chamber 44 separated by the oil separator 48.

[0032] The pressure (back pressure) in the back pressure chamber 39 generates a back pressure load that presses the movable scroll 22 against the fixed scroll 21. The movable scroll 22 overcomes the compression reaction force from the pressure chamber 34 of the scroll compression mechanism 4 and is pressed against the fixed scroll 21 by the back pressure load, and the contact between the volutes 24 and 32 and the cover plates 31 and 23 is maintained, so that the refrigerant can be compressed by the pressure chamber 34.

[0033] On the other hand, the inverter box 8 is composed of a box body 10 having an inverter housing portion 13 formed therein, and a cover member 15 that closes the opening of the box body 10. The inverter 3 is housed in the inverter housing portion 13, and the cover member 15 is attached to the box body 10 after the inverter 3 is housed in the inverter housing portion 13.

[0034] Next, refer to Figure 2 to Figure 4 The shape of the stator housing 7 of the electric compressor 1 of the embodiment will be described. As described above, one end of the stator housing 7 is open, and the open end surface serves as the gasket sealing surface 7B, and the other end is closed by the end wall 7A. On the inner surface of the stator housing 7, a plurality of (four locations in the embodiment) shrink-fit fixing surfaces 42 are formed at intervals to protrude inward, and each shrink-fit fixing surface 42 abuts against the outer surface of the stator 25. After the stator 25 is housed in the stator housing 7 from the opening, it is fixed to each shrink-fit fixing surface 42 by shrink-fitting.

[0035] On the inner surface of the stator housing 7 on the opening side (the opening side of one end of the stator housing 7) of the burn-in fixing surface 42, a plurality of fitting surfaces 46 (center plate fitting surfaces) for fitting with the aforementioned center plate 6 are formed in a manner protruding inward, and after the center plate 6 is accommodated in the stator housing 7 from the opening, it fits with the fitting surfaces 46 and is fixed to the stator housing 7.

[0036] In addition, a refrigerant passage 47 is formed on the inner surface of the stator housing 7 between the shrink-fitting surfaces 42 and the fitting surfaces 46. The refrigerant passage 47 is connected to the suction port 30 and the suction part 37, and the refrigerant sucked from the suction port 30 passes through the refrigerant passage 47 and is sucked into the scroll compression mechanism 4 through the suction part 47.

[0037] Furthermore, a plurality of ribs 49 (such as Figure 2 , Figure 3 As shown. Figure 1 In this case, each rib 49 is formed only on the opening side of one end of the stator housing 7, and the stator housing 7 is reinforced by the rib 49 to suppress deformation during burn-in.

[0038] By configuring as described above, the electric compressor 1 includes a cylindrical stator housing 7 with one end open, and a rear housing 9 joined to the opening of the stator housing 7 via a gasket 41. The stator 25 of the electric motor 4 is accommodated through the opening of the stator housing 7, and the stator 25 is fixed to the inner surface of the stator housing 7 by burn-fitting. In the electric compressor 1, a plurality of burn-fit fixing surfaces 42 for fixing the stator 25 are formed on the inner surface of the stator housing 7, and a gasket sealing surface 7B for providing the gasket 41 is formed on the open end surface of the stator housing 7. A plurality of ribs 49 are formed on the open side of the outer surface of the stator housing 7 corresponding to the burn-fit fixing surfaces 42. Therefore, the strength of the open side of the stator housing 7, which is most likely to be deformed when the stator 25 is burn-fitted, can be improved by the ribs 49.

[0039] Thus, deformation of the gasket sealing surface 7B with the rear housing 9 can be suppressed, and an increase in weight of the stator housing 7 due to the formation of the ribs 49 can be suppressed, thereby achieving weight reduction of the electric compressor 1.

[0040] In particular, in the electric compressor 1 including the center plate 6 and the scroll compression mechanism 4 as in the embodiment, it is possible to suppress deformation of the fitting surface 46 of the stator housing 6 while achieving weight reduction.

[0041] In addition, in the embodiment, the scroll electric compressor 1 is used as an example for explanation, but the invention of mode 1 and mode 2 is not limited to this, and the present invention is effective for various electric compressors. In addition, the specific shapes of the components shown in the embodiment are not limited to this, and can be changed within the scope of the main purpose of the present invention. Description of Reference Numerals

[0042] 1 Electric compressor 2 Electric motor (motor) 3 Inverter 4 Scroll compression mechanism (compression mechanism) 6 Center Plate 7 Stator housing 7B Gasket sealing surface 9 Rear housing 11. Housing 12 Motor room 13 Inverter storage area 30 suction port 37 Inhalation 42 Burn-in fixing surface 46 Fitting surface (center plate fitting surface) 47 Refrigerant channel 49 ribs.

Claims

1. An electric compressor, comprising a cylindrical stator housing with one end open, and a rear housing joined to the opening of the stator housing via a gasket, wherein a stator of a motor is received through the opening of the stator housing, and the stator is fixed to the inner surface of the stator housing by burn-fitting, characterized in that: include: A plurality of burn-in fixing surfaces are formed on the inner surface of the stator housing to fix the stator; A gasket sealing surface is formed on the open end surface of the stator housing and is provided with the gasket; as well as A plurality of ribs are formed on the opening side of the outer surface of the stator housing corresponding to the shrink-fit fixing surface.

2. The electric compressor according to claim 1, characterized in that: comprising a center plate received in the stator housing and located on the opening side of the motor, A fitting surface for fitting with the center plate is formed on the inner surface of the stator housing on the opening side of the shrink-fit fixing surface.

3. The electric compressor according to claim 2, characterized in that: A scroll compression mechanism is disposed in a space formed by the center plate and the rear housing.

4. The electric compressor according to claim 3, characterized in that: include: a refrigerant suction port formed at the other end of the stator housing; and A refrigerant passage is formed between the burn-in fixing surfaces to connect the suction port with the refrigerant suction portion of the scroll compression mechanism.

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