JP7153169B2 - electric compressor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric compressor containing an electric motor and a compression mechanism in a housing, and more particularly to a type of electric compressor in which the housing is divided into a plurality of parts in the axial direction of the electric motor and joined via gaskets. Regarding compressors.

As an electric compressor, an inverter-integrated electric compressor described in Patent Document 1 is known.
This electric compressor includes a housing (body case) that houses an electric motor and a compression mechanism, an inverter case that is open at one end and houses an inverter for driving the electric motor, and a lid-shaped inverter cover that closes the opening of the inverter case. and All of these are made of metal.

Here, the inverter case and the inverter cover are joined together with a gasket as a sealing material interposed between their annular joint surfaces. However, the gasket has insulating properties due to the rubber layer on the surface. Therefore, it is necessary to electrically connect the inverter case and the inverter cover. For this reason, on either one of the annular joint surfaces, a convex portion as an electrical connection portion is provided at a position inside the gasket so that the two are in direct contact with each other.

JP 2015-017577 A

By the way, as a casing structure of the electric compressor, a housing for accommodating the electric motor and the compression mechanism is divided into a first housing for accommodating the electric motor and a second housing for accommodating the compression mechanism. and a type in which the second housing is joined via a gasket.

In the case of an electric compressor having such a type of housing structure, a potential difference may occur between the first housing and the second housing. It can flow and be uncomfortable.
Therefore, it is required to equipotentialize the first housing and the second housing.

As a countermeasure for equipotentialization, similarly to the countermeasure in Patent Document 1, on the annular joint surface of the first or second housing, a convex portion as an electrical connection portion is provided at a position inside the gasket. can be considered.
However, if the width of the annular joint surface (the thickness of the housing) cannot be increased, it is difficult to take measures such as those disclosed in Patent Document 1.

Also, in the case of the inverter case and the inverter cover, it is conceivable to provide an electrical connection by providing a protruding portion rising from the inner bottom of the inverter case and bringing the tip of the protruding portion into contact with the inner surface of the inverter cover. (See Japanese Patent Application No. 2017-109158 filed by the present applicant).
However, since the electric motor is in the first housing and the compression mechanism is in the second housing, it is difficult to provide electrical connections within the housing.

SUMMARY OF THE INVENTION In view of such circumstances, an object of the present invention is to realize equipotential equalization between a first housing that houses an electric motor and a second housing that houses a compression mechanism with a relatively simple structure. and

An electric compressor according to the present invention comprises: a first metal housing containing an electric motor; a second metal housing containing a compression mechanism driven by the electric motor; and an annular gasket interposed between the annular joint surfaces of the housing. Further, the gasket has an electrical connection portion that enables electrical connection between the first and second housings.

Specifically, the gasket includes a metal substrate and rubber layers covering both surfaces thereof.
The gasket has annular beads on its inner edge side and outer edge side, respectively, and has through holes for bolts for fastening the first and second housings between the inner edge side bead and the outer edge side bead . have.
The gasket further has a metal substrate exposed portion formed between the beads on both sides of the gasket and formed by removing a portion of the rubber layer to expose the metal substrate.
The gasket has a convex surface between the bead on the inner edge side and the bead on the outer edge side on one side, and a concave surface between the bead on the inner edge side and the bead on the outer edge side on the other side. The metal substrate exposed portion of is formed at the edge of the through hole on the convex surface.
The gasket has a convex portion that protrudes from a part of the concave surface in the circumferential direction, and the metal substrate exposed portion on the other surface of the gasket is formed in the convex portion.
The metal base exposed portion on one side of the gasket and the metal base exposed portion on the other side are close to each other in the circumferential direction of the gasket.
Further, the metal substrate exposed portion constitutes an electrical connection portion that enables electrical connection between the first and second housings.

According to the present invention, by providing an electrical connection portion in the gasket itself (a part in the circumferential direction and a part in the width direction), it can be implemented without increasing the width of the joint surface, and the first and second Equipotentiality of the housing can be achieved.
In particular, it can be carried out very easily by providing a metal substrate exposed portion in the gasket. Moreover, by providing between the beads, it is possible to avoid the influence on the sealing performance.

1 is a vertical cross-sectional view of an electric compressor showing an embodiment of the present invention; A front view of the gasket corresponding to the AA arrow view of FIG. Back view of gasket same as above Enlarged view of B part of FIG. CC sectional view of FIG. DD sectional view of FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a longitudinal sectional view of an electric compressor showing one embodiment of the present invention. The electric compressor of the present embodiment is of a horizontal type (compressor center axis is horizontal), is incorporated in a refrigerant circuit of a vehicle air conditioner, sucks refrigerant, compresses it, and discharges it. Lubricating oil is mixed in the refrigerant.

The housing of the electric compressor 1 is divided into a plurality of parts in the direction of the central axis of the compressor. ) 4. These are integrally fastened as described later.

The front housing 2 is generally cylindrical and has a partition wall 5 in the middle in the axial direction. An electric motor housing space is formed on the right side of the partition wall 5 of the front housing 2, and the electric motor 6 is housed therein.
The electric motor 6 includes a rotating shaft 6a rotatably supported in the center of the front housing 2, a rotor 6b with permanent magnets attached around the rotating shaft 6a, and fixedly held on the inner wall of the front housing 2. and a stator 6c with an electromagnetic coil surrounding the rotor 6b.

An inverter storage space is formed on the left side of the partition wall 5 of the front housing 2, and an inverter (drive circuit for an electric motor) 7 is stored therein.
The inverter 7 controls power supply to the electric motor 6 while converting direct current from an external power source into alternating current.

More specifically, the inverter 7 uses a capacitor for smoothing the DC voltage from the external power supply and PWM control (control for generating a voltage whose pulse width is modulated at a constant cycle to obtain a pseudo sine wave). In order to drive the electric motor 6 based on control signals from a power module that converts the DC voltage from the capacitor into an AC voltage and supplies it to the coil on the stator 6c side of the electric motor 6 and an external air conditioning control device, A power module control circuit for controlling the power module is included.

The opening of the inverter housing space of the front housing 2 (in other words, the opening of the inverter case) is sealed with a lid-shaped inverter cover 8 .

The center housing 3 has a generally cylindrical shape and accommodates therein a compression mechanism 9 driven by an electric motor 6 .

The compression mechanism 9 of this embodiment is a scroll-type compression mechanism, and includes a fixed scroll member 10 , a movable scroll member 11 , and a crank mechanism portion 12 .
The fixed scroll member 10 and the movable scroll member 11 have spiral wraps 10b and 11b integrally formed on end plates 10a and 11a, respectively, and are arranged to face each other in the central axis direction.

The movable scroll member 11 orbits on a circular orbit around the central axis of the compressor by the rotary shaft 6a of the electric motor 6 via the crank mechanism 12, and is prevented from rotating.
As a result, the fluid pocket formed between the spiral wrap 10b of the fixed scroll member 10 and the spiral wrap 11b of the movable scroll member 11 moves from the outer peripheral side to the inner peripheral side while decreasing the volume, and the fluid flows at the outer peripheral side. Fluid (ie, refrigerant gas) entrained in the pockets is compressed.

A refrigerant suction port (not shown) is provided on the outer wall of the front housing 2 or the center housing 3 . Refrigerant sucked from the suction port flows through the front housing 2 to lubricate and cool the electric motor 6 (and cools the inverter 7 via the partition wall 5), and then flows into the center housing 3 to swirl. It is taken into the fluid pocket from the outer peripheral side of the wraps 10b and 11b and subjected to compression.

The compressed refrigerant is discharged from a discharge hole 13 with a one-way valve provided in the central portion of the end plate 10a of the fixed scroll member 10. As shown in FIG.

The rear housing 4 is arranged like a lid with respect to the center housing 3 , and forms a refrigerant discharge chamber 14 with an end plate 10 a of a fixed scroll member 10 fixed to the center housing 3 .
Therefore, the refrigerant compressed by the compression mechanism 9 is discharged from the discharge hole 13 into the discharge chamber 14 in the rear housing 4 and then discharged to the outside through the discharge port 15 provided on the outer wall of the rear housing 4 . .

Next, the fastening structure and sealing structure of the front housing 2, the center housing 3 and the rear housing 4 will be described.

The front housing 2 and the center housing 3 are joined with an annular gasket 16 interposed between their outer peripheral joint surfaces. The center housing 3 (and the end plate 10a) and the rear housing 4 are similarly joined with an annular gasket 17 interposed between their joint surfaces on the outer peripheral side.
Gaskets 16 and 17 are formed by providing rubber layers on both sides of a metal substrate, and have insulating properties with respect to members to be joined, as will be described in detail later.

The front housing 2, the center housing 3, and the rear housing 4 are fastened together with a plurality of (for example, six) bolts 18 arranged at suitable intervals in the circumferential direction.

Each bolt 18 passes through the rear housing 4 and the center housing 3 from the rear housing 4 side in parallel with the central axis of the compressor and is screwed into the front housing 2 .

Accordingly, bolt holes are formed in the rear housing 4 and the center housing 3 . The gaskets 17 and 16 are also formed with bolt holes. The front housing 2 is formed with screw holes 2s into which the bolts 18 are screwed.
The bolt 18 has the bearing surface of the head thereof locked to the rear housing 4 , the shaft portion passing through the bolt through holes of the rear housing 4 , the gasket 17 , the center housing 3 and the gasket 16 , and the threaded portion of the tip of the bolt 18 passing through the front housing 2 . It is screwed into the screw hole 2s.

Therefore, the front housing 2 and the rear housing 4 are electrically connected through the bolts 18, although they are not in direct contact with each other. This is because the head of the bolt 18 is in contact with the rear housing 4 with sufficient contact pressure, and the threaded portion of the bolt 18 is in contact with the threaded hole 2s of the front housing 2 with sufficient contact pressure.

On the other hand, the front housing 2 and the center housing 3 are not electrically connected. This is because the insulating gasket 16 is interposed to prevent direct contact, and the bolt 18 is only loosely fitted in the bolt through hole of the center housing 3 .

Therefore, in this embodiment, the gasket 16 between the front housing 2 and the center housing 3 is provided with equal potential.
The detailed structure of the gasket 16 and countermeasures for potential equalization will be described with reference to FIGS. 2 to 6. FIG.

2 is a front view of the gasket 16 corresponding to the AA arrow view of FIG. 1, FIG. 3 is a rear view of the gasket 16, FIG. 4 is an enlarged view of the B part of FIG. 2, and FIG. C sectional view, and FIG. 6 is a DD sectional view of FIG.

The gasket 16 is formed by stamping a metal plate coated with a rubber layer into an annular shape, and processing a bead at the same time as the stamping, before or after the stamping.
Therefore, as shown in FIG. 5 (and FIG. 6), the gasket 16 includes a metal substrate 16a and rubber layers 16b covering both surfaces thereof. The thickness of the metal substrate 16a is about 0.2 mm, and the thickness of each of the rubber layers 16b on both sides is about 0.1 mm.

The gasket 16 has annular beads (half beads) 101 and 102 on its inner edge side and outer edge side, respectively.
The inner side of the bead 101 on the inner edge side and the outer side of the bead 102 on the outer edge side serve as bearing surfaces (reference surfaces) 103 and 104 .
A space between the bead 101 on the inner edge side and the bead 102 on the outer edge side becomes a convex surface (convex plane) 105 when viewed from the front side, and a concave surface (concave plane) 106 when viewed from the rear side.

When assembling the front housing 2, the center housing 3, and the rear housing 4, generally, the front housing 2 is set on a jig with its joining surface facing up, and the gasket 16, the center housing 3, and the gasket 16 are mounted on the jig. The gasket 17 and the rear housing 4 are placed and set in this order. Therefore, the gasket 16 faces down for better seating.
In this case, the seating surfaces 103 and 104 (and the concave surface 106) of the gasket 16 are on the front housing 2 side, and the convex surface 105 of the gasket 16 is on the center housing 3 side.

The gasket 16 also has, for example, six bolt holes 107 and two positioning holes 108 between the bead 101 on the inner edge side and the bead 102 on the outer edge side.
The bolt through holes 107 are through holes for the bolts 18 that fasten the rear housing 4, the center housing 3 and the front housing 2, as described above.
The positioning hole 108 is a positioning hole for setting the gasket 16 on the front housing 2 during assembly. For such positioning, a positioning pin 19 (see FIG. 1) protrudes from the joint surface on the front housing 2 side. A guide hole 20 (see FIG. 1) into which the positioning pin 19 is fitted is formed in the joint surface on the center housing 3 side.

The shape and structure of the gasket 16 described above are the same for the gasket 17 as well.
The following shape and structure are adopted as the shape and structure specific to the gasket 16 for countermeasures for potential equalization.

Between the bead 101 on the inner edge side and the bead 102 on the outer edge side of the gasket 16, an electrical connection 109 is formed on the side of the convex surface 105 at the edge of any one of the bolt through holes 107 ( 2, 4 and 6).
The electrical connection portion 109 is a metal substrate exposed portion obtained by removing (for example, scraping off) the rubber layer of the corresponding portion to expose the metal substrate.

Between the bead 101 on the inner edge side of the gasket 16 and the bead 102 on the outer edge side, a convex portion 110 projecting in a circular shape is formed on the side of the concave surface 106 (see FIGS. 3 and 6). The convex portion 110 is a convex portion when viewed from the back side and a concave portion 110' when viewed from the front side.
An electrical connection portion 111 is formed at the edge of the circular projection 110 on the concave surface 106 side between the bead 101 on the inner edge side and the bead 102 on the outer edge side of the gasket 16 (FIGS. 3 and 6). reference).
The electrical connection portion 111 is a metal substrate exposed portion obtained by removing (for example, scraping off) the rubber layer of the portion to expose the metal substrate.

The convex portion 110 is provided close to the bolt through hole 107 in which the electrical connection portion 109 is formed. For example, the distance in the circumferential direction between the bolt through hole 107 forming the electrical connection portion 109 and the protrusion 110 is set to be shorter than the distance in the circumferential direction between the other bolt through hole 107 and the protrusion 110. do. As a result, the electrical connection portion (metal base exposed portion) 109 on one side of the gasket 16 and the electrical connection portion (metal base exposed portion) 111 on the other side of the gasket 16 come close to each other in the circumferential direction of the gasket 16. .

By using the gasket 16 having such a structure, the following effects can be obtained.
The corners of the beads 101 and 102 of the gasket 16 are crushed between the front housing 2 and the center housing 3 by fastening them. Thereby, the joint surfaces of the front housing 2 and the center housing 3 are reliably sealed.

Therefore, since the joint surfaces of the front housing 2 and the center housing 3 are sealed by generating contact pressure at the corners of the beads 101 and 102 of the gasket 16, the bead 101 on the inner edge side and the bead 102 on the outer edge side are sealed. does not affect the seal during

Therefore, a part (109) of one surface between the bead 101 on the inner edge side and the bead 102 on the outer edge side is removed to expose the metal base material, and a part (111) of the other surface is removed. ) to expose the metal substrate.

By providing the metal substrate exposed portions 109 and 111 on both sides in this way, the gasket 16 is crushed by the tightening axial force, so that the front housing 2 and the center housing 3 are separated through the metal substrate exposed portions 109 and 111. It can make metal contact and ensure equipotentiality.

Here, on the convex surface 105 side between the beads 101 and 102 of the gasket 16 , a metal substrate exposed portion 109 is provided at the edge of the bolt through hole 107 . Since the axial force of the bolt 18 reliably acts on this portion and the surface pressure increases, the gasket is easily crushed and the contact pressure is high. Therefore, electrical connection can be ensured.

A convex portion 110 is provided on the side of the concave surface 106 between the beads 101 and 102 of the gasket 16, and a metal substrate exposed portion 111 is provided at the edge thereof. As a result, the surface pressure of this portion can be increased to secure the contact pressure and ensure the electrical connection.

In addition, the metal substrate exposed portions 109 and 111 on both sides are slightly separated in the circumferential direction, but are close to each other in the circumferential direction. Connections can be made over relatively short distances without damaging these electrical connections.

According to this embodiment, the gasket 16 has an electrical connection that enables electrical connection of the first and second housings (the front housing 2 and the center housing 3), so that the width of the joint Equipotentiality of the first and second housings can be achieved without increasing .

Further, according to this embodiment, the gasket 16 includes a metal substrate 16a and rubber layers 16b covering both surfaces thereof, and the electrical connection portions are formed on both surfaces of the gasket 16, respectively. These are metal base exposed portions 109 and 111 obtained by removing part of the layer 16b to expose the metal base 16a. Therefore, it can be easily implemented using existing gaskets.

Further, according to this embodiment, the gasket 16 has annular beads 101 and 102 on its inner edge side and outer edge side, respectively, and has a through hole 107 for the bolt 18 between the beads 101 and 102, The metal substrate exposed portions 109 and 111 are formed between the beads 101 and 102 . Therefore, it is possible to avoid the influence on the sealing property.

Further, according to this embodiment, the gasket 16 has a convex surface 105 between the beads 101 and 102 on one surface thereof, and a concave surface 106 between the beads 101 and 102 on the other surface of the gasket 16 . The metal substrate exposed portion 109 is formed at the edge of the through hole 107 on the convex surface 105 . Since the fastening axial force is high and the contact pressure is high in the vicinity of the through hole 107, electrical connection can be ensured.

Further, according to the present embodiment, the gasket 16 has a convex portion 110 protruding from the concave surface 106 , and the metal substrate exposed portion 111 on the other surface of the gasket 16 is formed on the convex portion 110 . By doing so, the contact pressure can be increased even on the side of the concave surface 106, and electrical connection can be ensured.

Further, according to the present embodiment, the metal base exposed portion 109 on one side of the gasket 16 and the metal base exposed portion 111 on the other side are close to each other in the circumferential direction of the gasket 16. . As a result, the connection distance for electrical connection via the metal substrate 16a can be shortened.

Returning to FIG. 1, measures for equalizing the potentials of the inverter case portion of the front housing 2 and the inverter cover 8 will be described.
The inverter case portion of the front housing 2 and the inverter cover 8 are joined and fixed via an insulating gasket 21 .
Here, a projecting portion 22 rising from the inner bottom of the inverter case of the front housing 2 is provided, and the tip of the projecting portion 22 is brought into contact with the inner surface of the inverter cover 8, whereby electrical connection can be made. In this case, the inverter cover 8 is slightly deformed.

In the above description, the electrical connection is provided only in the gasket 16 between the first housing (front housing 2) and the second housing (center housing 3). A gasket 17 between the housing 3) and the third housing (rear housing 4) may also be provided with a similar electrical connection.

It should be noted that the illustrated embodiment is merely an example of the present invention, and the present invention includes various modifications and improvements made by those skilled in the art within the scope of the claims in addition to what is directly shown by the described embodiment. It goes without saying that changes are included.
For example, in the above description, an existing gasket is processed, but a new gasket having electrical connections may be created.

1 electric compressor 2 front housing (first housing)
2s screw hole 3 center housing (second housing)
4 rear housing (third housing)
5 Partition Wall 6 Electric Motor 6a Rotating Shaft 6b Rotor 6c Stator 7 Inverter 8 Inverter Cover 9 Compression Mechanism 10 Fixed Scroll Member 10a End Plate 10b Spiral Wrap 11 Movable Scroll Member 11a End Plate 11b Spiral Wrap 12 Crank Mechanism Part 13 Discharge Hole 14 Discharge Chamber 15 Discharge port 16 Gasket 16a Metal substrate 16b Rubber layer 17 Gasket 18 Bolt 19 Positioning pin 20 Guide hole 21 Gasket 22 Protruding parts 101, 102 from the inner bottom of the inverter case Beads 103, 104 Seat surface (reference surface)
105 convex surface (convex plane)
106 concave surface (concave plane)
107 bolt through hole 108 positioning hole 109 electrical connection portion (metal substrate exposed portion)
110 convex portion 111 electrical connection portion (metal base exposed portion)

Claims (1)

A first housing made of metal that houses an electric motor, a second housing made of metal that houses a compression mechanism driven by the electric motor, and between annular joint surfaces of the first and second housings. In an electric compressor comprising an interposed annular gasket,
The gasket comprises a metal base material and rubber layers covering both sides thereof,
The gasket has annular beads on its inner edge side and outer edge side, respectively, and has through holes for bolts for fastening the first and second housings between the inner edge side bead and the outer edge side bead . have
The gasket further has a metal substrate exposed portion formed between the beads on both sides of the gasket and formed by removing a part of the rubber layer to expose the metal substrate,
The gasket has a convex surface between the bead on the inner edge side and the bead on the outer edge side on one side, and a concave surface between the bead on the inner edge side and the bead on the outer edge side on the other side. The metal substrate exposed portion of is formed at the edge of the through hole on the convex surface,
The gasket has a convex portion that protrudes from a part of the concave surface in the circumferential direction, and the metal substrate exposed portion on the other surface of the gasket is formed in the convex portion,
the metal base exposed portion on one side of the gasket and the metal base exposed portion on the other side are close to each other in the circumferential direction of the gasket,
The electric compressor according to claim 1, wherein the metal substrate exposed portion forms an electrical connection portion enabling electrical connection between the first and second housings.

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