JPS62139994A - Rotary compressor - Google Patents

Abstract

PURPOSE:To prevent a rotor and cylinder from being subjected to abnormal wear due to contact with each other by disposing an intermediate member having the coefficient of thermal expansion larger than that of a side plate on a portion of the outer periphery of a bearing to absorb a difference between the thermal expansion amounts of the bearing and side plate with said member. CONSTITUTION:Intermediate members 20 made of synthetic resin having the coefficient of thermal expansion larger than that of aluminum alloy side plates 6, 7 having the coefficient of thermal expansion larger than that of iron system bearings 8, 9 are disposed on at least a portion of the bearings 8, 9, and side plates 6, 7. Thus, a difference between the thermal expansion amounts of the bearings 8, 9 and side plates 6, 7 will be absorbed by the intermediate members 20. As a result, in temperature rise, a rotor 3 will not contact a cylinder 1 and further a top gap 2 between the rotor 3 and cylinder 1 can be initially set small to provide a rotary compressor with few leakage, high efficiency and reliability and light weight.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rotary compressor used in a cooling device for an automobile or the like.

Conventional technology Compressors used in automobile cooling systems are installed in narrow engine compartments and driven by a belt by the engine, so they have to meet requirements such as being smaller, lighter, quieter, and able to withstand high speed rotation. There are many. In recent years, rotary compressors, which are particularly small and quiet, have been increasingly adopted in place of conventional reciprocating compressors.

However, due to the harsh operating conditions mentioned above, rotary compressors lag behind conventional reciprocating compressors in terms of weight reduction. One of the difficulties is managing the gap between the rotating member and the stationary member. That is, in the rotary type, the gap must be made smaller than in the reciprocating type.
In order to secure this gap, it is difficult to maintain the rigidity of the members, especially the strain control caused by pressure and heat. For example, in FIG. 5, 1 is a cylinder having an inner wall, a top gap 2 is provided, and a rotor 3 is disposed within the cylinder 1.

There are a plurality of radial slits within the rotor 3, through which the vanes 5 slide. Reference numerals 6 and 7 are front and rear plates that close the cylinder 1 from the front and back, and the rotor 3 is connected to the front bearing 8. It is supported by a rear bearing 9 via a shirt 10.

Here, the cylinder 1 and rotor 3 are assembled with a top gap 2 set, but if this top gap 2 is too wide, it will significantly impair the performance of the compressor. If it is too narrow, the rotor 3 will hit the cylinder 1, causing abnormal wear and problems such as seizure of the compressor.

Problems to be Solved by the Invention By the way, when the front and rear side plates 6 and 7 are made of aluminum alloy,
The above-mentioned phenomenon becomes even more severe.

That is, the bearings 8.9 are iron-based bearings such as needle roller bearings, and the front plate 6.9 is a bearing block. When the rear plate 7 is made of an aluminum alloy, there is a difference of approximately twice the coefficient of thermal expansion between the two. As a result, when the compressor temperature increases, bearing 8
The fitting margin between the side plates 6 and 7 is reduced, and a gap is created between the two. Therefore, during rotation, the rotor 3 may have some play and may move in the direction of the top clearance 2 with respect to the cylinder 1, making it more likely that the rotor 3 will be attached to the cylinder 1.

Therefore, in order to make the side plates 6 and 7 made of aluminum alloy, the top gap 2 had to be set slightly wider than in the case of side plates made of ferrous metal.

In view of the above-mentioned drawbacks, the present invention has been developed to provide a lightweight lightweight construction that does not cause abnormal wear due to contact between the rotor and cylinder even when the temperature of the members increases, and allows the gap between the rotor and cylinder to be set small. The purpose is to provide a rotary compressor.

Means for Solving the Problems In the present invention, the above-mentioned problems are addressed by the following configuration. That is, the side plate has a larger coefficient of thermal expansion than the bearing, and an intermediate member made of a material with a coefficient of thermal expansion smaller than that of the bearing is disposed on at least a portion of the outer periphery of the bearing.

Function In the conventional configuration, when the temperature of each member rises uniformly, for example, the thermal expansion coefficient of the aluminum alloy side plate (bearing block) is approximately 19 x 1 d-6, and the thermal expansion coefficient of the iron-based bearing is approximately 19 x 1 d-6. Since the coefficient is larger than approximately 11×10=, in the conventional configuration, the press-fit margin (usually about 20 μm at room temperature) disappears at a temperature above a certain level, and conversely, a gap occurs. In the configuration of the present invention, an intermediate member with a thermal expansion coefficient lower than that of aluminum alloy is placed between the bearing and the side plate (bearing block), so the difference in thermal expansion between the bearing and the side plate (bearing block) is The component absorbs.

As a result, the press-fit margins and gaps that occur in the past are eliminated, and the contact between the rotor and cylinder when the temperature rises is eliminated, and the top gap between the rotor and cylinder can be initially set small. It is possible to create a lightweight rotary compressor with low leakage, high efficiency, and high reliability.

Embodiment FIG. 1 is a longitudinal sectional view of a rotary compressor which is an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. 1
1 is a cylinder having a cylindrical inner wall, and a rotor 3 is eccentrically disposed inside the cylinder 1 with a top gap 2 separating the cylinder 1 and the top gap 2. A plurality of radial slits 4 are provided in the rotor 3.
There is a vane 5 inserted therein so as to be freely retractable. 6 is a front side plate, and 7 is a rear side plate, both of which are made of aluminum alloy. 2
゜ is the front plate 6. An intermediate member made of synthetic resin (preferably fluororesin) is press-fitted into each of the rear side plates 7, and each intermediate member 20.20 further includes a front bearing 8 and a rear bearing made of iron-based material. 9 are press-fitted concentrically.

Each of the bearings 8 and 9 supports a shaft 1o that is integral with the rotor 3.

In the above configuration, the temperature of the compressor increases.

Thermal expansion of the front side plate 6, the intermediate member 20, and the bearing 8 will be considered. The coefficient of thermal expansion of each is αB, αR9αJ, the inner diameter of the large engineering hole in the front plate 6 is 21B, and the thickness of the intermediate member is tl.
, assuming that the outer ring diameter of the bearing is 211, in order for the intermediate member 2o to absorb the difference in thermal expansion between the bearing 8 and the front plate 6, t ZH: (RJ+t) (ZB-RJ IIJ=
R, (αB-αJ)+taaB (119X106.a engineering=11X10-6.R1=12
．． 55B.

B- If it is t-2 parrot αR=619X1゜ 9. Resin-based materials are preferred from the viewpoint of thermal expansion coefficient.

FIG. 3 shows a second embodiment of the invention.

In this embodiment, the aforementioned intermediate member 20 is eccentric to the bearing 8, and the thick wall portion 21 of the intermediate member 2o is located in the direction of the aforementioned top gap 2 between the rotor 3 and the cylinder 1.

The purpose of this configuration is that in addition to the contact between the rotor 3 and the cylinder 1 due to the generation of a gap between the bearing outer ring and the bearing block as described in the conventional example, when the rotor 3 rotates at high speed, the bearing section generates heat. This is intended to prevent the top gap 2 from decreasing or disappearing due to the temperature becoming higher than the temperature of the cylinder 1.

That is, by configuring the intermediate member 2o and the bearing 8 to be eccentric, when the temperature rises, the thick portion 21 of the intermediate member 2o has a larger amount of thermal expansion. Move in the direction of enlargement. As a result, the top gap 2 is offset by the above-described difference in thermal expansion between the rotor 3 and the cylinder 1 and is kept constant, so that abnormal wear due to contact between the rotor 3 and the cylinder 1 can be prevented.

FIG. 4 shows a third embodiment of the present invention, in which an intermediate member 2o having a larger coefficient of thermal expansion than the side plate 6 is positioned between the bearing 8 and the front plate 6, which is a bearing block, on the side of the top gap 2. It is press-fitted.

In the embodiment described above, the side plates 6 and 7 are made of aluminum alloy,
Although the intermediate member 20 is made of synthetic resin, it is clear that the same effect can be obtained if both are made of aluminum alloy and the components are made to be different so that the intermediate member 2o has a larger coefficient of thermal expansion.

Effects of the Invention As described above, according to the present invention, a rotary compressor with extremely excellent durability and high performance can be provided by simply arranging an intermediate member having a larger coefficient of thermal expansion than the side plate on the outside of the bearing. can do.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a rotary compressor according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIGS. 3 and 4 each show other embodiments of the present invention. cross section,
FIG. 6 is a longitudinal sectional view of a compression section of a conventional rotary compressor. 1...Cylinder, 2...Top clearance,
3°...rotor, 6.7...side plate, 8.
9...Bearing, 20...Intermediate member, 21
・・・・・・Thick part. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
figure

Claims (2)

[Claims] (1) A rotary compressor comprising a rotor that operates with a top gap formed inside a cylinder, and a side plate that receives a bearing that supports the rotor and has a larger coefficient of thermal expansion than the bearing that closes the cylinder, A rotary compressor, wherein an intermediate member having a larger coefficient of thermal expansion than the side plate is disposed on at least a part of the outer periphery of the bearing. (2) The rotary compressor according to claim 1, wherein the intermediate member is thick in the direction of the top gap or is press-fitted only in the direction of the top gap with respect to the center of the bearing.