JP2001165041A - Swash plate type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swash plate type compressor of high productivity preventing seizure of a shoe and a swash plate from being easily generated to enhance reliability and decrease man-hours of manufacture with no difficult work required. SOLUTION: This compressor, provided with a swash plate 85 making a rotary motion by a rotational drive source, piston 180 capable of reciprocating motion in a parallel direction to a piston center axis in a cylinder bore 16, and a slide surface of rotary unit surface shape with a shoe center axis serving as the center, has shoes 186, 187 interposed between the swash plate 85 and the piston 180 for converting the rotary motion of the swash plate 85 into the linear reciprocating motion of the piston 180. A relative angle between the piston center axis and the shoe center axis is not changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type compressor suitable for use in an air conditioner mounted on a motor vehicle.
In particular, the present invention relates to an improvement of a mechanism for converting a rotational motion of a swash plate into a linear reciprocating motion of a piston.

[0002]

2. Description of the Related Art Referring to FIG. 4, one example of a conventional swash plate type compressor is a swash plate type fixed displacement compressor included in a refrigeration circuit of an air conditioner for a vehicle, which is provided in a casing having a closed space. The refrigerant gas containing the lubricating oil is sucked, and the compressed refrigerant gas is discharged out of the casing. The casing includes a front housing 3, a cylinder block 4,
It comprises a valve plate 6 and a cylinder head 5.
The cylinder block 4 has a plurality of, for example, seven cylinder bores 16 formed around the axis. A plurality of pistons 80 are respectively housed in the cylinder bores 16 so as to be slidable in the axial direction. These pistons 80
Reciprocate in the cylinder bore 16 in accordance with the rotation of the swash plate 85 caused by the rotation of the drive shaft 8. In the crank chamber 42 formed in the front housing 3, a pair of shoes 86 are provided between the swash plate 85 and the sliding surfaces 83 and 84 formed on the piston 80 and having a substantially hemispherical concave shape.
And 87 are interposed. In other words, the pair of shoes 86 and 87 are connected to the swash plate 8 within the U-shaped piston connecting portion 82 at one end of the piston 80.
5 is inserted. The piston connecting portion 82
Outside the cylinder bore 16 and the front housing 3
Located within.

Referring to FIGS. 4 and 5, shoes 86 and 87 each have a first planar sliding surface 86a that slides on the plate surface of swash plate 85 and a sliding surface of piston 80. And a second sliding surface 86b having a hemispherical convex shape that slides on the surfaces 83 and 84.

[0004]

In the conventional compressor described above, including the example shown in FIG. 4, the shoe and the swash plate are in contact with each other and slide with a relatively large contact area. Therefore, the lubricating oil on the surface of the swash plate is easily wiped by the relatively large flat surface of the shoe. For this reason, there is a problem that seizure between the shoe and the swash plate easily occurs.

[0005] Conventional compressors are also inferior in productivity because a pair of hemispherical concave surfaces must be machined on the piston. In particular, the hemispherical concave surfaces of the pair of pistons must be formed inside the U-shaped piston connecting portion, and are difficult to machine.

An object of the present invention is to provide a highly reliable swash plate type compressor which is less likely to cause seizure between a shoe and a swash plate.

Another object of the present invention is to provide a swash plate type compressor which has a small number of manufacturing steps and high productivity without requiring difficult processing.

[0008]

According to the present invention, the following swash plate type compressors (1) to (6) can be obtained.

(1) A swash plate that rotates by a rotary drive source, a piston that can reciprocate in a direction parallel to the piston central axis in a cylinder bore, and sliding of the rotating body surface shape about the shoe central axis. A swash plate type compressor having a surface, and a shoe interposed between the swash plate and the piston for converting a rotational movement of the swash plate into a linear reciprocating motion of the piston. A swash plate type compressor, wherein a relative angle with respect to the shoe center axis is invariable.

(2) The swash plate compressor according to (1), wherein the sliding surface of the shoe is a curved surface.

(3) The swash plate compressor according to (1), wherein the sliding surface of the shoe is a flat surface.

(4) The shoe has the center axis of the shoe parallel or coaxial with the center axis of the piston.
The swash plate compressor according to any one of (1) to (3), which is fixed to the piston.

(5) The shoe has the center axis of the shoe parallel or coaxial with the center axis of the piston.
The swash plate compressor according to any one of (1) to (3), wherein the swash plate compressor is loosely fitted to the piston so as to be rotatable about the center axis of the shoe.

(6) One pair of the shoes is provided for each of the pistons, and each of the pair of shoes includes a convex portion extending coaxially with the center axis of the shoe. A piston connection part having a U-shaped cross section is provided at one end in the direction, and a pair of concave parts are formed on two opposite sides of the piston connection part in parallel or coaxially with the piston central axis. In the pair of shoes, each of the protrusions is a pair of shoes such that the center axis of each shoe is parallel or coaxial with the center axis of a piston, and the swash plate is sandwiched between the sliding surfaces. The swash plate type compressor according to (4) or (5) inserted into each of the recesses.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a swash plate type compressor according to an embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 1, this swash plate type compressor is a swash plate type fixed displacement compressor included in a refrigeration circuit of an automobile air conditioner, similarly to a conventional example, and has a casing having a closed space. The refrigerant gas is sucked into the compressor and the compressed refrigerant gas is discharged out of the casing.

The casing includes a front housing 3 and
It comprises a cylinder block 4 and a cylinder head 5. At the center of the cylinder block 4, a drive shaft 8 that extends in the axial direction and is rotatable is provided. The front housing 3, the cylinder block 4, and the cylinder head 5 are fastened and fixed by a plurality of bolts (not shown) through which these are commonly inserted. One end of the drive shaft 8 is exposed to the outside through the front housing 3 fixed to one end of the cylinder block 4 in the axial direction, and is connected to an external power source via an electromagnetic clutch so as to be able to be appropriately detached. A cylinder head 5 is fixed to the other axial end of the cylinder block 4 via a valve plate 6. One end of the drive shaft 8 has an inner wall hole 31 formed in a shaft support portion 30 protruding outward from a central portion of the front housing 3.
Are rotatably supported via a radial bearing 11 and a shaft sealing device. The other end of the drive shaft 8 is supported by a shaft hole 41 formed in the center of the cylinder block 4 via a bearing device. The bearing device is provided with a needle bearing 14 that is in contact with the other end surface of the drive shaft 8.

In the cylinder block 4, a plurality of, for example, seven cylinder bores 16 are formed around the axis. These cylinder bores 16 include seven pistons 18.
0 are slidably fitted in the axial direction, respectively. Each of the pistons 80 linearly reciprocates in the cylinder bore 16 according to the rotation of the drive shaft 8. A swash plate 85 rotated by the drive shaft 8 is provided in the crank chamber 42 formed in the cylinder block 4.

The rotational movement of the swash plate 85 is converted into a reciprocating movement of a piston 180 connected via a shoe described later. A discharge hole 61 and a suction hole 62 are formed in the valve plate 6 so as to correspond to each cylinder bore 16.
A leaf valve 64 as a discharge valve faces the discharge hole 61. A retainer 65 is provided on the leaf valve. The cylinder head 5 has a central discharge chamber 53 and a suction chamber 52 extending therearound. The discharge chamber 53 is connected to the high pressure side of the refrigeration circuit through a discharge port (not shown), and supplies high pressure gas to the condenser. The suction chamber 52 is connected to the low-pressure side of the refrigeration circuit through a suction path including a gas passage and a suction port, and receives a return gas from the evaporator.

Referring to FIG. 1, FIG. 2 and FIG. 3 (a), the present swash plate type compressor has a sliding surface 186a having a rotating body surface shape about the center axis of the shoe. And a pair of shoes 186 and 187 interposed between the piston 180 and the piston 180 to convert the rotational movement of the swash plate 85 into a linear reciprocating movement of the piston 180. The relative angles of the piston center axis and the shoe center axis do not change during the operation of the swash plate compressor. Shoes 186 and 187
The sliding surface 186a has a partially spherical shape.

As is apparent from FIG.
Has a U-shaped piston connecting portion 182 at one end side, similarly to the conventional example shown in FIG. In the piston connecting portion 182, mounting through holes 183 and 184 are formed coaxially with the piston center axis. On the other hand, each of the shoes 186 and 187 has a column portion 186c (FIG. 3A). Since the inner diameters of the mounting through holes 183 and 184 are formed slightly larger than the outer diameter of the cylindrical portion, the shoes 186 and 187 respectively
The shoe central axis is parallel or coaxial with the piston central axis, and is loosely fitted into the mounting through holes 183 and 184 so as to be rotatable about the shoe central axis.

According to the structure of the swash plate type compressor described above, the swash plate 85 and the shoes 186 and 187 are formed in a plane.
In the state of spherical contact and contact and sliding with a relatively small contact area, the lubricating oil on the swash plate surface is unlikely to be wiped by the relatively large surface of the shoe as in the past,
Therefore, seizure between the shoe and the swash plate is unlikely to occur.

In addition to the fact that the shoes 186 and 187 have the same simple and simple rotating body shape as the conventional one (for example, can be easily processed by a lathe), the piston 180 has a pair of mounting through holes 183 coaxially. And 184, it is not necessary to form a partial spherical concave portion inside the piston connecting portion as in the conventional example, and the productivity is excellent. A swash plate 85 is provided between the pair of shoes 186 and 187.
186 and 187 during the assembly process of inserting
The cylindrical portion 186c has through holes 183 and 18 for mounting.
4, it does not come off easily, and the assembling work is easy.

The shoes 186 and 187 need not be rotatably loosely fitted into the mounting through holes 183 and 184, but may be fixedly fitted or screwed. However, shoes 186 and 187
It is advantageous to have a degree of freedom by loosely fitting in terms of suppressing wear between the swash plate and the shoe. Further, as the loose fitting structure, instead of simply providing a gap between the outer diameter of the shoe and the inner diameter of the mounting through hole to allow lubricating oil to permeate, a friction reducing bearing structure such as using a bearing may be used.

FIG. 3B shows a modified example of the shoe in the swash plate type compressor according to the present invention. Referring to FIG. 3A, a shoe 186 'includes a sliding surface 186a' having a rotating body surface shape about the center axis of the shoe and a cylindrical portion 186c, and the shoe 186 shown in FIG. , 187 can be used for the present swash plate compressor. Even when the shoe 186 'is used, the relative angle between the piston center axis and the shoe center axis does not change during the operation of the swash plate compressor. The sliding surface 186a 'of the shoe 186' has a substantially conical surface shape, and its apex angle and base angle are rounded.

The sliding surface 186 a ′ of the shoe 186 ′ has a contact with the swash plate 85 and a sliding area of the conventional shoe 8 ′.
6 is smaller than the first sliding surface 86a (FIG. 5), while the sliding surface 186a of the shoe 186 (187) (FIG. 3A).
Greater than. For this reason, the lubricating oil on the surface of the swash plate is wiped by a relatively large surface area of the shoe as in the related art, and is not seized on the swash plate. Is too small, which is advantageous for the problem of wear between the swash plate and the shoe.

Note that the shoes 186 'are also
Similar to 87, it may be rotatably loosely fitted or fixed in the mounting through holes 183 and 184, or may be supported by a friction reducing bearing structure.

[0028]

The swash plate type compressor according to the present invention comprises a swash plate which is rotated by a rotary drive source, a piston which can reciprocate in a direction parallel to the piston center axis in the cylinder bore, and a shoe center axis. And a shoe interposed between the swash plate and the piston for converting the rotational motion of the swash plate into a linear reciprocating motion of the piston. Since the relative angle between the center axis and the center axis is invariable, seizure between the shoe and the swash plate hardly occurs and the reliability is high.

Further, the number of manufacturing steps is small, no difficult processing is required, and the productivity is high.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a swash plate type compressor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a main configuration of a swash plate compressor according to the embodiment of the present invention.

FIGS. 3A and 3B are side views showing a shoe of a swash plate type compressor according to an embodiment of the present invention and a modified example thereof.

FIG. 4 is a sectional view showing a configuration of a conventional swash plate type compressor.

FIG. 5 is a side view showing a shoe of a conventional swash plate type compressor.

[Explanation of symbols]

 Reference Signs List 3 front housing 4 cylinder block 5 cylinder head 6 valve plate 8 drive shaft 16 cylinder bore 42 crank chamber 53 discharge chamber 52 suction chamber 61 discharge hole 62 suction hole 64 leaf valve 65 retainer 80, 180 piston 82, 182 piston connection part 83, 84 Sliding surface 85 Swash plate 86, 87, 186, 187, 186 'Shoe 86a First sliding surface 86b Second sliding surface 183, 184 Mounting through hole 186a, 186a' Sliding surface 186c Cylindrical portion

Claims (6)

[Claims] 1. A swash plate that is rotated by a rotary drive source, a piston that can reciprocate in a direction parallel to a piston central axis in a cylinder bore, and a sliding surface having a rotating body surface shape about a shoe central axis. A swash plate type compressor having a shoe interposed between the swash plate and the piston for converting a rotational motion of the swash plate into a linear reciprocating motion of the piston. A swash plate type compressor characterized in that a relative angle with respect to a shoe center axis is invariable. 2. The swash plate compressor according to claim 1, wherein the sliding surface of the shoe is a curved surface. 3. The swash plate compressor according to claim 1, wherein the sliding surface of the shoe is a flat surface. 4. The swash plate compressor according to claim 1, wherein the shoe is fixed to the piston with the center axis of the shoe parallel or coaxial with the center axis of the piston. 5. The shoe is loosely fitted to the piston so that the center axis of the shoe is parallel or coaxial with the center axis of the piston, and the shoe is rotatable about the center axis of the shoe. A swash plate type compressor according to any one of the above. 6. A pair of the shoes is provided for each of the pistons, and each of the pairs of the shoes has a convex portion extending coaxially with respect to the center axis of the shoe, and the piston is arranged in the axial direction of the piston. Is provided with a piston connecting portion having a U-shaped cross section on one end side, and a pair of concave portions are formed on two opposite sides of the piston connecting portion in parallel or coaxially with the piston central axis. The pair of shoes is such that each of the protrusions is a pair of the shoes so that the center axis of each shoe is parallel or coaxial with the center axis of the piston, and the swash plate is sandwiched between the sliding surfaces. The swash plate compressor according to claim 4, wherein the swash plate compressor is inserted into each of the recesses.