JP2013177827A - Electric compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inverter integrated electric compressor that can improve sealing property by surely transmitting force for tightening and fixing by bolts to a cover.SOLUTION: An inverter housing part 14 for housing an inverter device for supplying drive power to an electric motor 20 is provided at an outer periphery of a housing 11 for housing the electric motor 20 and a compressing mechanism 30. The inverter housing part 14 includes an inverter box 15 having a housing chamber at an inner side of a sidewall 15a, and an inverter cover 16 for covering an opening of the inverter box 15, and is fixed to the inverter box 15 by bolts B2. The bolts B2 which are adjacent along a circumferential direction of the inverter box 15 are tightened to fix the inverter cover 16 while one of them is tightened at an outer side of the sidewall 15a and the other is tightened at the inner side of the sidewall 15a.

Description

  The present invention relates to an electric compressor used for an in-vehicle air conditioner.

  A scroll-type compressor often used in an air conditioner includes a fixed scroll and a turning scroll each having a spiral scroll wall. Then, the orbiting scroll is revolved with respect to the fixed scroll to reduce the volume of the compression chamber formed between both scroll walls, thereby compressing the fluid in the compression chamber.

  In recent years, an electric compressor driven by an electric motor is being used in an air conditioner for a vehicle. In such an electric compressor, in the inverter device, a direct current supplied from the battery is converted into an alternating current, and the alternating current is supplied to rotate the electric motor to drive the compressor.

  In an air conditioner for a vehicle, space saving is required in order to accommodate each device in the engine room of the vehicle. Then, the electric compressor assembled | attached to the housing in which the compressor, the electric motor, and the inverter apparatus were integrated is provided (for example, patent document 1). This inverter-integrated electric compressor includes a storage chamber that houses the inverter device, and is sealed by tightening and fixing a lid to the opening with a bolt to achieve waterproofing of the storage chamber. In order to ensure waterproofness, a sealing agent such as a liquid gasket is applied to the sealing surface for hermetic sealing, but it is difficult to apply the sealing agent uniformly. It was difficult to ensure uniform sealing performance, and there was a risk of flooding in the inverter housing. Therefore, Patent Document 1 proposes providing a groove filled with a sealing agent.

JP 2010-59941 A

Patent Document 1 is effective in securing the sealing performance, but before relying on the sealing agent, it is necessary to fasten and fix the lid with a stronger force in order to obtain the sealing performance more reliably.
Accordingly, the present invention has been made based on such a problem, and provides an inverter-integrated electric compressor capable of improving the sealing performance by more reliably transmitting a force to be fastened and fixed by a bolt to the lid. Objective.

An inverter-integrated electric compressor according to the present invention, which is based on this object, has an inverter housing portion that houses an inverter device that supplies driving power to an electric motor on the outer periphery of a housing in which the motor and the compression mechanism are housed. Prepare.
The inverter accommodating part by this invention is equipped with the accommodating main body which has an accommodating chamber inside a side wall, and the lid | cover which closes the opening of an accommodating main body, and fastens and fixes a lid | cover to a accommodating main body with a fastener. The first fastener and the second fastener adjacent to each other along the circumferential direction of the housing body are fastened and fixed by the first fastener on the outside of the side wall and the second fastener on the inside of the side wall.
In the electric compressor of the present invention, the first fastener is outside the side wall and the second fastener is inside the side wall by tightening and fixing the lid, thereby increasing the surface pressure between the housing body and the lid. , Ensure the necessary sealing.

  In the electric compressor of the present invention, it is preferable that at least one of the first fastener and the second fastener is provided in a bent portion that is recessed toward the accommodation chamber. If it is this bending part, it will become difficult to obstruct the member and apparatus which are arranged around.

  Moreover, in the electric compressor of the present invention, the top surface of the side wall while the first fastener and the second fastener are fastened and fixed protrudes from the other region, so that the surface pressure is improved. It is advantageous.

  As in the electric compressor of the present invention, when the bosses adjacent to the side wall of the inverter housing portion are provided, one on the inner side of the side wall and the other on the outer side of the side wall, the load connecting one fastener to the other fastener. Since the line of action intersects the side wall, the lid can be fixed to the side wall with a strong force.

It is a figure which shows the compressor in this embodiment, and is sectional drawing along the axial direction of the compressor. It is a top view which shows the inside of an inverter box. It is a figure explaining the action position of the load at the time of fastening and fixing an inverter cover to an inverter box. It is a top view which shows an inverter cover from the top plate side. It is a top view which shows the other example of an inverter cover. It is a top view which shows the other example of an inverter cover.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
As shown in FIG. 1, the electric compressor 10 includes a housing 11 that forms an outline thereof. The housing 11 includes a compressor side housing 12 that houses a scroll type compression mechanism 30, an electric motor side housing 13 that houses an electric motor 20, and an inverter housing portion 14 that houses an inverter device (not shown). These housing components are manufactured by die casting an aluminum alloy.

  The electric compressor 10 has a refrigerant introduced into the housing 11 from a refrigerant suction port (not shown) formed on the side surface of the motor-side housing 13, and from a refrigerant discharge port P2 formed on the end surface of the compressor-side housing 12. The refrigerant compressed by the compression mechanism 30 is discharged.

The electric motor 20 includes a rotor 21 and a stator 22 that are integrally provided on the main shaft 40. The electric compressor 10 is characterized in that a rotor 21 is disposed around a stator 22.
The rotor 21 is composed of a laminated body in which electromagnetic steel plates each having a slit for accommodating a permanent magnet are laminated, and a permanent magnet disposed in the slit of the laminated body (electromagnetic steel plate), which is the same as in the known art. It is. A shaft hole 21 a penetrating in the axial direction is formed around the axis of the rotor 21. The motor side shaft 40a of the main shaft 40 passes through the shaft hole 21a.
The rotor 21 is fixed to the main shaft 40 (motor-side shaft 40a) by press-fitting or other methods, thereby rotating the main shaft 40 integrally.

  The stator 22 is disposed around the rotor 21. The stator 22 has a general configuration in which a coil is wound, and has a cylindrical appearance. The stator 22 is press-fitted into the motor-side housing 13 and fixed by other methods. Inside the stator 22, the rotor 21 is arranged with a minute interval.

  The main shaft 40 is rotatably supported by the housing 11 via a main bearing 41 and a sub bearing 42. The main bearing 41 supports the journal portion 40b of the main shaft 40 having a large diameter, and the sub bearing 42 supports the motor side shaft 40a. The rotor 21 is assembled integrally with the main shaft 40 between the main bearing 41 and the sub bearing 42.

The compression mechanism 30 includes a turning scroll 32 that rotates together with the main shaft 40, and a fixed scroll 33 that is fixed to the housing 11.
In the orbiting scroll 32 and the fixed scroll 33, spiral scroll walls 32b and 33b are provided upright on one side of the disk-like end plates 32a and 33a, respectively. The orbiting scroll 32 and the fixed scroll 33 combine the scroll walls 32b and 33b with each other to form a compression chamber 35 between the scroll walls 32b and 33b.

At the end (one end) of the main shaft 40 on the compression mechanism 30 side, an eccentric shaft 40c is formed to protrude from the central axis of the main shaft 40 by a predetermined dimension. The orbiting scroll 32 is rotatably held on the eccentric shaft 40 c via a drive bush 44 and a drive bearing 45. Thereby, the orbiting scroll 32 is eccentric by a predetermined dimension with respect to the center of the main shaft 40, and when the main shaft 40 rotates around its axis, the orbiting scroll 32 is eccentric with respect to the center of the main shaft 40. Rotate (revolution) with a radius. Thereby, the volume of the compression chamber 35 decreases and the refrigerant is compressed. The Oldham ring 36 is interposed between the orbiting scroll 32 and the main shaft 40 so that the orbiting scroll 32 does not rotate while revolving.
In addition, a balancer 46 is provided between the orbiting scroll 32 and the main shaft 40 in order to eliminate unbalance due to the orbiting scroll 32 eccentric to the main shaft 40.

Now, the inverter accommodating portion 14 includes an inverter box (accommodating body) 15 and an inverter cover (lid) 16. The inverter box 15 has a box shape with one opening, and an inverter device (not shown) is accommodated therein. The inverter device controls the power supplied to the electric motor 20. The opening end of the inverter box 15 is sealed by the inverter cover 16, and the bottom plate 15 f of the inverter box 15 facing the inverter cover 16 closes the opening by contacting the motor-side housing 13. The inverter box 15 is fixed to the motor-side housing 13 by bolts B1, and the inverter cover 16 is fixed to the inverter box 15 by bolts B2.
A boss 17 that supports the sub-bearing 42 is formed on the bottom plate 15 f of the inverter box 15 toward the electric motor 20. The sub bearing 42 rotatably supports the main shaft 40 (motor side shaft 40a) while being supported and fixed by the boss 17.

In FIG. 2, the top view which looked at the inverter box 15 from the opening side is shown.
The inverter box 15 includes a side wall 15a rising in the axial direction of the electric compressor 10, a storage chamber 15c provided inside the side wall 15a, and bosses 15d provided at a plurality of locations along the side wall 15a. Each boss 15d is formed with a screw hole 15e into which the bolt B2 is screwed. The inverter cover 16 placed on the top surface 15b of the side wall 15a is fastened and fixed to the side wall 15a with the bolt B2, thereby hermetically sealing the accommodation chamber 15c.

In the present embodiment, the bosses 15d are provided in a total of eight locations, and the numbers (Nos. 1 to 8) shown in FIG. The number of the bosses 15d provided is merely an example.
The boss 15d is provided on the inner side of the side wall 15a of the inverter box 15, and protrudes toward the accommodation chamber 15c. This is so as not to obstruct the members and devices arranged around the inverter box 15. However, No. 4 and No. 8 bosses 15d are provided inside the side wall 15a. This is due to the following reason. Suppose that the boss 15d of No. 4 is provided inside the side wall 15a as shown in FIG. If the inverter cover 16 is fastened and fixed by the bolt B2 at the No. 3 boss 15d and the No. 4 boss 15d, the load generated between the No. 3 boss 15d and the No. 4 boss 15d by tightening is as follows. , the center of the boss 15d and No.4 boss 15d of No.3, namely acting along the line of action _{L 2} connecting the centers of two bolts B1. However this action line L ₂ are offset from the top surface 15b of the side wall 15a as shown in FIG. 3 (B), the surface pressure is sufficiently obtained between the inverter cover 16 and the top surface 15b by tightening the bolt B2 I can't.

On the other hand, in the case of this embodiment in which the No. 3 bosses 15d are alternately arranged on the inner side of the side wall 15a and the No. 4 bosses 15d on the outer side of the side wall 15a, as shown in FIG. .3 boss 15d (bolts B2, fasteners) action line _{L 1} connecting the center of the No.4 boss 15d (bolts B2, fasteners) traverses the top surface 15b of the side wall 15a. Therefore, since the surface pressure between the inverter cover 16 and the top surface 15b due to the tightening force by the bolt B2 can be increased, the sealing performance of the inverter box 15 and the inverter cover 16 can be improved. In order to obtain a higher surface pressure, the top surface 15b is preferably protruded from other regions, for example, the top surface 15b between the No. 1 boss 15d and the No. 2 boss 15d.
Therefore, according to the present embodiment, since the airtight state inside the inverter accommodating portion 14 is kept high, it is possible to prevent damage caused by moisture and other substances that are desired to avoid intrusion.

Among the bosses 15d arranged alternately as described above, the No. 4 boss 15d is provided at a portion where the side wall 15a is bent. This bending occurs at the connecting portion between the circular portion (right side in the drawing) and the rectangular portion (left side in the drawing), and is bent toward the accommodation chamber, that is, the inside. Because of the concave bent portion, even if the boss 15d is arranged outside the side wall 15a, the surroundings are hardly hindered. Therefore, one of the bosses 15d arranged alternately is preferably provided in a region where the side wall 15a is bent inward.
In the electric compressor 10, the bosses 15d of No.2, No.3, No.4 and No.5, and the bosses 15d of No.7, No.8 and No.1 are alternately arranged. This is merely an example, and the bosses 15d arranged alternately are appropriately determined according to the shape and dimensions of the inverter box 15 (inverter cover 16). It is clear that a predetermined effect can be obtained if only one set of alternate relationships is included, and the present invention includes this embodiment.

  Next, on the top plate 16a of the inverter cover 16 facing the storage chamber 15c in a state of being mounted on the inverter box 15, as shown in FIG. 4, a seat surface 16b attached to the top surface 15b of the inverter box 15 is provided. It is formed along the periphery. The seat surface 16b protrudes from the top plate 16a by a minute amount. Boss 16d is provided at a plurality of locations along the seat surface 16b. Each boss 16d corresponds to the boss 15d of the inverter box 15, and in order to fasten and fix the inverter cover 16 to the inverter box 15 with the bolt B2, the corresponding boss 15d and the boss 16d are aligned, and the bolt hole 16e is aligned. , 15e, and bolt B2 is screwed in.

The inverter cover 16 has a plurality of ribs 16c formed on the top plate 16a. The rib 16 c is a characteristic part of the electric compressor 10, and the rib 16 c suppresses the noise from the inverter cover 16 by suppressing the vibration of the inverter cover 16. That is, if the top plate 16a is flat, the inverter cover 16 fixed to the inverter box 15 may cause a drumming phenomenon as the inverter device is driven. On the other hand, providing the rib 16c increases the rigidity of the top plate 16a and suppresses the occurrence of vibration.
The rib 16c connects the two bosses 16d and the boss 16d. Since the portion provided with the boss 16d has higher rigidity than the seat surface 16b without the boss 16d, the effect obtained by providing the rib 16c becomes remarkable.
The form which provides the rib 16c is arbitrary. As shown in FIG. 4, each rib 16c can be provided so as not to be engaged with the other ribs 16c (except around the boss 16d as a starting point), or as shown in FIG. It can also be provided.
Further, the rib 16c is not limited to a linear shape, and may include a curved portion (circle) as shown in FIG. Moreover, as shown in FIG. 6, the circular rib 16c connected indirectly to the boss | hub 16d can be provided by connecting the some linear rib 16c.
In addition, the inverter cover 16 provided with the rib 16c as described above can be manufactured without any special work by integral molding by die casting.

In the electric compressor 10 configured as described above, the low-pressure refrigerant gas after being circulated in the refrigeration cycle is sucked into a motor-side housing 13 from a refrigerant suction port (not shown) and circulated in the motor-side housing 13. It is sucked into the compression mechanism 30. The refrigerant gas compressed by the compression mechanism 30 to become high temperature and pressure is circulated from the refrigerant discharge port P2 provided at the end of the compressor side housing 12 to the refrigeration cycle through the discharge pipe.
In this process, when electric power is supplied to the stator 22 while being controlled by an inverter device (not shown), the rotor 21 is rotationally driven. Then, the main shaft 40 fixed to the rotor 21 is rotationally driven integrally with the rotor 21 and the orbiting scroll 32 performs the orbiting motion. The main shaft 40 has a journal portion 40b whose diameter is larger than that of the other portion, is supported by the main bearing 41, and the motor-side shaft 40a is supported by the sub-bearing 42 held inside the stator 22, Driven by rotation.

Since the No. 3 boss 15d is arranged inside the side wall 15a and the No. 4 boss 15d is arranged outside the side wall 15a, the airtightness in the inverter accommodating portion 14 can be maintained at a high level. The risk of the inverter device losing its function due to flooding is extremely low.
In addition, the inverter device vibrates when it operates, but since the top plate 16a of the inverter cover 16 has a plurality of ribs 16c on the back side, noise diffused to the surroundings through the inverter cover 16 is reduced. Can be reduced.

In the said embodiment, although the inverter accommodating part 14 demonstrated the example which applied this invention to the electric compressor 10 arrange | positioned coaxially with the compression mechanism 30 and the electric motor 20, this is an example to the last, an inverter accommodating part The present invention can be applied to an inverter-integrated electric compressor 14 provided on the side of the electric motor 20.
In the above-described embodiment, the scroll type compression mechanism 30 has been described. However, this is only an example, and an electric motor provided with a rotary type compression mechanism or a multistage type compression mechanism that combines a scroll type and a rotary type. The present invention can be applied to a compressor.
In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

DESCRIPTION OF SYMBOLS 10 Electric compressor 11 Housing 12 Compressor side housing 13 Motor side housing 14 Inverter accommodating part 15 Inverter box 15a Side wall 15b Top surface 15c Accommodating chamber 15d Boss 15e, 16e Screw hole 16 Inverter cover 16a Top plate 16b Seat surface 16c Rib 16d Boss 17 boss 20 motor 21 rotor 22 stator 30 compression mechanism 32 orbiting scroll 33 fixed scroll 35 compression chamber 40 spindle 40a motor-side shaft 40b journal portion 40c eccentric shaft 41 main bearing 42 sub bearing B1, B2 bolt _L 1, _{L 2} line of action

Claims (3)

On the outer periphery of the housing in which the electric motor and the compression mechanism are accommodated, an inverter accommodating portion that accommodates an inverter device that supplies driving electric power to the electric motor,
The inverter housing
A storage body having a storage chamber inside the side wall; and a lid for closing the opening of the storage body;
Fastening and fixing the lid to the housing body with a fastener,
The first fastener and the second fastener adjacent to each other along the circumferential direction of the housing main body are fastened and fixed by the first fastener outside the side wall and the second fastener inside the side wall.
An electric compressor characterized by that. At least one of the first fastener and the second fastener is provided in a bent portion that is recessed toward the storage chamber;
The electric compressor according to claim 1. The top surface of the side wall while the first fastener and the second fastener are fastened and fixed protrudes from other regions.
The electric compressor according to claim 1 or 2.

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