JPH07301176A - Double head swash plate type compressor - Google Patents

Abstract

PURPOSE:To reduce vibration, and increase service life of a thrust bearing. CONSTITUTION:Pressure receiving seats 51, 31 to hold at least one of thrust bearings 6A, 6B provided before and after a swash plate 5 are formed in the shape of a truncated cone having an outward-expanded micro-gap to a race to which at least one of them is applied, and thereby unbalanced load to be applied to a track surface of the thrust bearing 6B is reduced to improve its durability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-headed swash plate compressor, and more particularly to improvement of a thrust bearing portion for receiving an axial load of the swash plate.

[0002]

2. Description of the Related Art Most of the double-headed swash plate type compressors used for vehicle air conditioning have a pair of cylinder blocks 10A, 10B as disclosed in Japanese Patent Laid-Open No. 64-63669.
A swash plate 12 is mounted on a drive shaft 11 supported by the thrust shaft 13, and the thrust bearings 13 are provided in front of and behind the swash plate 12,
The cylinder block 10 is sandwiched between the cylinder blocks 10A and 10B and the housings 14 and 15 that close the outer ends of the cylinder blocks 10 and 15 together by a through bolt 16. In order to absorb the interference in the axial direction due to the joint tightening by the elastic deformation generated in the race of the thrust bearing 13, the inner race 13a has an annular pressure receiving seat 12a formed on both boss portions of the swash plate 12 near its outer diameter. And, on the other hand,
The outer race 13b has an annular pressure receiving seat 10a formed on the bearings of the cylinder blocks 10A and 10B near the inner diameter thereof.
(Fig. 7).

[0003]

The axial load generated by the compression reaction force of the refrigerant gas due to the rotation of the swash plate 12 is received by the thrust bearings 13 and 13 described above. Both of them are configured to positively elastically deform (cushioning function) by sandwiching the annular pressure receiving seats 10a and 12a having different diameters as described above. Therefore, as shown in FIG. Swash plate 1
This effectively results in the interposition of spring means S on both sides of 2. That is, the moment that the compression reaction force acts on the swash plate 12 is
Mutual buffering of the spring means S, S induces unstable vibration in the swash plate 12, and the frequency component having strong transparency particularly at the time of high speed rotation further promotes noise disturbance.

[0004] On the other hand, on the other hand
As disclosed in the publication, there is also a type in which both thrust bearings are rigidly held by using both bosses of the swash plate and both bearings of the cylinder block as flat pressure receiving seats. When the moment based on the compression reaction force acts on the swash plate, the inner race that abuts the pressure receiving seat of the swash plate on all the planes is strongly pressed by the outer end of the rolling element (roller). There is a problem that such an unbalanced load applied to the rollers not only accelerates the wear of the thrust bearing extremely, but also has a considerable influence on the generation of vibration and noise and power loss.

An object of the present invention is to reduce the vibration and noise with a very simple structure and to extend the life of the thrust bearing at the same time.

[0006]

According to a first aspect of the invention for solving the above-mentioned problems, a pressure-receiving seat formed on a boss portion of a swash plate that cooperates with a drive shaft and a pressure-receiving seat formed on a pair of cylinder blocks. In a double-headed swash plate compressor in which thrust bearings are respectively sandwiched between the bearings, the pressure-receiving seats that sandwich at least one thrust bearing, at least one of them is
It is characterized in that it is formed in a frusto-conical shape that has a minute play like an outer flank between it and the abutting race. In addition,
In the type in which the thrust bearings arranged on both sides of the swash plate are both rigidly sandwiched, it is desirable to apply the above-mentioned pressure bearing structure to both thrust bearings.

According to the second aspect of the present invention, the pressure receiving seat formed on the boss portion of the swash plate holding at least one thrust bearing acts on the pressure receiving seat with respect to a plane orthogonal to the drive axis. The feature is that it is slightly inclined toward the position where the moment is maximum. In a preferred mode, the other thrust bearing sandwiched by the pressure receiving seats has a cushioning function of absorbing an axial load.

In a preferred mode, the cushioning function is an elastic deformability of the race itself provided by annular pressure receiving seats having different diameters that sandwich the other thrust bearing. In a preferred mode, the cushioning function is an elastic deformability unique to a spring member interposed between the other thrust bearing and the cylinder block.

[0009]

Therefore, when the moment based on the compression reaction force acts on the swash plate, the thrust bearing is clamped in a rigid manner (both opposing pressure receiving seats abut against the thrust bearing on a flat surface). In that case, since the moment is mainly received by the thrust bearing, a strong unbalanced load is exerted especially on the outer peripheral area of the raceway surface (the surface portion on which the rollers roll) via both pressure bearing seats and races that abut against this. However, since at least one of the pressure receiving seats is formed into a truncated cone shape and has a microscopic play of an outward flare between the abutting races, it is possible to receive the acting moment. The radial load that supports the drive shaft divides the load, and the unbalanced load that acts on the raceway surface of the thrust bearing is reasonably reduced.

Further, the pressure receiving seat formed on the boss portion of the swash plate holding at least one thrust bearing has a position where the moment acting on the pressure receiving seat becomes maximum with respect to the plane orthogonal to the drive axis. Even if it is tilted in the direction of, the slight unevenness that spreads toward the dead center position of the swash plate is secured between it and the abutting race, so the eccentric load acting on the raceway surface is also reduced. It

With one thrust bearing sandwiched in this way, the other thrust bearing is provided with a cushioning function to absorb the axial load, and the axial interference during assembly of the compressor is the other. It is skillfully absorbed by the shock-absorbing function of the thrust bearing, and even when the above-mentioned moment due to the compression reaction force acts on the swash plate during operation of the compressor, the rigidity of one thrust bearing sandwiched by the rigid The unstable vibration of the swash plate is effectively suppressed, and the fluctuating axial load is well absorbed by the cushioning function imparted to the other thrust bearing.

[0012]

EXAMPLE An example of the present invention will be specifically described below with reference to FIG. Since there is no particular change in the overall configuration of the compressor, detailed description thereof will be omitted.
In the figure, reference numeral 1 denotes a drive shaft supported by a front cylinder block 2 and a rear cylinder block 3 via radial bearings 4 and 4, and a swash plate 5 mounted on the drive shaft 1.
Thrust bearings 6A and 6B are provided in front of and behind the pressure bearing seats formed on both boss portions of the swash plate 5 and both cylinder blocks by co-tightening through bolts similar to the conventional thrust bearings 6A and 6B. It is sandwiched between the pressure receiving seats formed in a few.

The pinching means for the thrust bearings 6A and 6B, which is the most characteristic feature of the present invention, will be described in detail below. In the present embodiment, the thrust bearings 6A and 6B are both rigidly pinched, specifically, Since both pressure receiving seats facing each other have flat pressure receiving surfaces, and both have exactly the same structure, only the thrust bearing 6B will be described.

The thrust bearing 6B comprises an inner race 61, an outer race 62, a roller 63 and a retainer (not shown), and a flat pressure receiving seat 31 formed on the cylinder block 3 abuts against all side surfaces of the outer race 62. On the other hand, the pressure receiving seat 51 formed on the boss portion of the swash plate 5 is formed into a truncated cone shape, and has an outwardly extending microscopic clearance α (about 0.02 mm) between the abutting inner race 61. ~ 0.5 °) is retained. The characteristic structure of the pressure receiving seat 51 is not limited to the pressure receiving seat 51 formed on the boss portion of the swash plate 5, and as shown in FIG. Can be applied to both the pressure receiving seats 51 and 31.

FIG. 3 shows a modification of the pressure receiving seat 51. The pressure receiving seat 51 has a swash plate which maximizes the moment acting on the pressure receiving seat 51 with respect to a plane orthogonal to the drive axis. It is tilted in the same direction as the tilt angle (to be precise, a position direction slightly advanced in the rotation direction from the bottom dead center of the swash plate 5), and in this example, between the inner race 61 and the inner race 61 that abuts. A slight play β that spreads toward the dead center of the swash plate 5
(About 0.02 to 0.5 °) is secured.

Therefore, when the moment based on the compression reaction force acts on the swash plate 5, the thrust bearing, for example, 6B is rigidly held (both opposing pressure receiving seats abut on the thrust bearing on a flat surface). In the case of the type, since the moment is mainly received by the thrust bearing 6B, the raceway surface (the surface portion on which the roller rolls) passes through both the pressure receiving seats 51, 31 and the inner race 61 and the outer race 62 that abut against them. ), A strong unbalanced load is exerted particularly in the outer peripheral region, but at least one pressure receiving seat, for example, 51 is formed in a truncated cone shape, and an outer spreading minute clearance is formed between it and the abutting inner race 61. Since α is held, the receiving of the acting moment is divided by the radial bearing 4 supporting the drive shaft 1, and the eccentric load acting on the raceway surface of the thrust bearing 6B is reasonably low. It is.

At least one thrust bearing 6B
The pressure receiving seat 51 formed on the boss portion of the swash plate 5 that holds the
As shown in FIG. 3, even when it is tilted in the direction of the position where the moment acting on the pressure receiving seat 51 is maximized with respect to the plane orthogonal to the drive axis, the space between it and the inner race 61 that abuts. Since a slight play β that spreads toward the dead center position of the swash plate 5 is secured, the unbalanced load acting on the raceway surface is similarly reduced.

In another embodiment shown in FIG. 4, for example, one thrust bearing 6B is rigidly sandwiched by the unique pressure receiving seat structure as described above, and the other thrust bearing 6A has a buffer function of absorbing an axial load. It was given.
That is, a relatively large diameter annular pressure receiving seat 5a is formed on the boss portion of the swash plate 5 that holds the thrust bearing 6A, and the inner race 61 abuts the annular pressure receiving seat 5a near its outer diameter.
On the other hand, the cylinder block 2 is formed with an annular pressure receiving seat 2a having a relatively small diameter, and the outer race 62 is configured to abut against the annular pressure receiving seat 2a in the vicinity of the inner diameter thereof.
In this embodiment, the inner race 61 of both thrust bearings 6A and 6B is formed to have a larger diameter than the outer race 62 from the viewpoint of the function of the thrust bearing 6A and the common use of parts.

Therefore, when both boss portions of the swash plate 5 are sandwiched by the co-fastening members including both cylinder blocks 2 and 3 via the thrust bearings 6A and 6B, annular pressure receiving seats 5a and 2a having different diameters are formed. Since the races 61 and 62 of the thrust bearing 6A that abut against each other are elastically deformed, and the interference of the axial direction is skillfully absorbed by the cushioning function, the co-tightening tightening force can be adjusted easily and stably. it can.

When the compressor is operated, a moment based on the compression reaction force acts on the swash plate 5, but one thrust bearing 6B held by the rigid supports the swash plate 5 stably due to its rigidity. At the same time, the above-mentioned pressure receiving seat configuration also functions well in reducing the eccentric load acting on the thrust bearing 6B, and the fluctuating axial load is skillfully absorbed by the above-mentioned cushioning function imparted to the other thrust bearing 6A.

FIG. 5 shows a modification of the cushioning function provided to the other thrust bearing 6A.
The 0 front boss has a flat pressure receiving seat 50a and abuts on the inner race 61, while the outer race 62 abuts on the disc spring 8 mounted on the cylinder block 20 via the washer 7. . In other words, this embodiment does not require the thrust bearing 6A itself to have a cushioning function to absorb the axial load, but depends on the elastic deformation inherent to the spring member (disc spring 8) interposed between the thrust bearing 6A and the cylinder block 20. It has a feature and has an advantage that the selection of the spring constant is extremely easy.

In the above embodiment, the structure in which the front thrust bearing 6A is provided with a cushioning function has been described, but this may be applied to any of the front and rear thrust bearings. In addition to the disc spring, a coil spring, a roll spring or the like can be adopted.

[0023]

As described above in detail, since the present invention has the structure described in the claims, the unbalanced load acting on the raceway surface of the thrust bearing is reduced and the durability of the thrust bearing is reduced. In addition, the other of the above thrust bearings with a cushioning function to absorb the axial load not only absorbs the axial interference at the time of assembly, but also the thermal influence and fluctuating axial force. It can cope well with the load.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of a compressor according to an embodiment of the present invention.

FIG. 2 is a sectional view of a local portion showing a modification of the embodiment of the present invention.

FIG. 3 is a sectional view of an essential part showing another modification of the same.

FIG. 4 is a sectional view showing a main part of a compressor according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view of a main part showing a modified mode of another embodiment of the present invention.

FIG. 6 is an enlarged explanatory view schematically showing a load absorbing function of a conventional thrust bearing.

FIG. 7 is a cross-sectional view showing the entire structure of a conventional compressor.

[Explanation of symbols]

1 is a drive shaft, 2 and 20 are front cylinder blocks, 3 is a rear cylinder block, 5 and 50 are swash plates, 31 and 51
Is a pressure seat, 6A and 6B are thrust bearings, 61 is an inner race, 62 is an outer race, and 8 is a disc spring.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Mizuno 2-chome Toyota-cho, Kariya city, Aichi stock company Toyota Industries Corporation (72) Inventor Hayato Ikeda 2-chome Toyota-cho, Kariya city, Aichi stock Incorporated Toyota Industries Corporation (72) Inventor Naoto Kawamura 2-chome Toyota Town, Kariya City, Aichi Stock Company Incorporated Toyota Industries Corporation (72) Inventor Michel Alberda 2-chome Toyota Town, Kariya City, Aichi Prefecture Stock Company Toyota Loom Works

Claims (5)

[Claims] 1. A double-headed swash plate type compression device in which thrust bearings are sandwiched between a pressure receiving seat formed on a boss portion of a swash plate that cooperates with a drive shaft and a pressure receiving seat formed on a pair of cylinder blocks. In the machine, at least one of the pressure receiving seats for sandwiching at least one thrust bearing is formed in a truncated cone shape having at least one of the outwardly extending microscopic clearances with the abutting races. A double-headed swash plate compressor. 2. A double-headed swash plate type compression device in which thrust bearings are sandwiched between a pressure receiving seat formed on a boss portion of a swash plate that cooperates with a drive shaft and a pressure receiving seat formed on a pair of cylinder blocks. In the machine, the pressure receiving seat formed on the boss portion of the swash plate holding at least one thrust bearing is located at a position where the moment acting on the pressure receiving seat is maximum with respect to the plane orthogonal to the drive axis. A double-headed swash plate compressor characterized by being slightly tilted in the direction. 3. The compressor according to claim 1, wherein the other thrust bearing sandwiched between the pressure receiving seats is provided with a cushioning function for absorbing an axial load. 4. The compressor according to claim 3, wherein the cushioning function is an elastic deformability of the race itself provided by annular pressure receiving seats having different diameters that sandwich the other thrust bearing. 5. The compressor according to claim 3, wherein the cushioning function is an elastic deformability unique to a spring member interposed between the other thrust bearing and the cylinder block.