JPH03194187A - Rotary compressor - Google Patents

Abstract

PURPOSE:To suppress vibration during high speed rotation by making a rotary compressor in such a construction that the rotary shaft of a motor for driving the compressing device accommodated in a sealed case is borne by an upper and a lower bearing of the compressing device, and therein protruding up the rotary shaft above the rotor and supporting the top with a third bearing. CONSTITUTION:A motor 2 installed in the upper part of a sealed case 1 is composed of a stator 3 fixed to the inner wall of the sealed case 1 and a rotor 5 accommodated inside of the stator with a gap reserved and rotating as in a single piece with a rotary shaft 4, and a compressing device 8 is driven with rotation of the rotary shaft 4. This rotary shaft 4 is supported rotatably by No.1 and No.2 bearing 9, 10 at an upper and a lower point of the compressing chamber of the compressing device 8. Therein the top of the rotary shaft 4 is protruded up above the oversurface of the rotor 5, and the top is supported rotatably by a third bearing 11. This third bearing 11 is formed dividedly consisting of a bearing bracket 12 fixed to the stator 3 and a bearing 13 fixed to this bearing bracket 12.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a rotary compressor used in an air conditioner, etc.
More specifically, the present invention relates to a structure for further reducing vibrations generated during high-speed rotation.

[Conventional technology]

As shown in FIG. 3, the rotary compressor has a motor 22 disposed in the upper part of a sealed case 21, and a compression device 23 for compressing the bath medium as the motor 22 rotates in the lower part. The rotating shaft 24 of the motor 22 is rotatably supported by a first bearing 25 and a second bearing 26 formed on the upper and lower surfaces of the compression device 23. In order to cancel the imbalance of the shaft histone part (not shown) in the
An upper balancer 28 and a lower balancer 29 are attached to a rotor 27 fixed to the rotor 4.

However, during high-speed rotation under inverter control, the centrifugal force of the upper balancer 28 increases, bending and deforming the rotating shaft 24, causing a problem in which the rotor 27 comes into contact with the stator 3o.

As a countermeasure, the weight of the upper balancer 2 is made lighter than necessary for balance to reduce bending and deformation of the rotating shaft 24.

[Problem to be solved by the invention]

However, as mentioned above, in order to reduce the bending deformation of the rotating shaft during high-speed rotation, if the weight of the upper balancer is made lighter than the weight necessary for balance, the rotation of the rotating shaft becomes unbalanced, causing vibration. Become the source.

Further, in order to ensure mechanical safety even if the above-mentioned bending deformation occurs, it is necessary to use a highly rigid and expensive material for the rotating shaft.

Therefore, an object of the present invention is to solve these problems and provide a rotary compressor that can further reduce bending and deformation of the rotating shaft even during high-speed rotation.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and includes a motor disposed in the upper part of a sealed case, and a refrigerant compressed in the lower part as the motor rotates. A rotary compressor is provided with a compression device, and a rotary shaft of the motor is rotatably supported by first and second bearings formed on an upper surface and a lower surface of the compression device. The rotation axis
A third bearing was provided which protruded from the upper surface of the rotor fixed to the rotary shaft and rotatably supported the protruded rotary shaft.

[Function] With the above configuration, the upper end of the rotating shaft can be rotatably supported by the third bearing, so that wobbling of the rotating shaft can be suppressed and occurrence of bending deformation of the rotating shaft can be prevented.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 and 2.

Fig. 1 is a vertical side view schematically showing the internal structure of a rotary compressor, where ■ is a sealed case, 2 is a motor disposed at the upper part of the sealed case 1, and a stator 3 that constitutes the motor 2. is fixed to the inner wall of the sealed case 1, and an upper balancer 6 and a lower balancer 7 are attached to a rotor 5 fixed to a rotating shaft 4.

Reference numeral 8 denotes a compression device disposed at the lower part of the sealed case 1. The outer periphery of the compression device 8 is fixed to the inner wall of the sealed case I, and there is a compression device inside that compresses the refrigerant as the motor 2 rotates. A chamber, etc. is formed, and the upper and lower walls of the compression chamber are provided with a first bearing 9 that rotatably supports the rotating shaft 4 of the motor 2.
and a second bearing 10.

Incidentally, the upper end of the rotating shaft 4 projects higher than the upper surface of the rotor 5 fixed to the rotating shaft 4, and the projecting portion is rotatably supported by a third bearing 11. .

The third bearing 11 is divided into a ring-shaped bearing bracket 12 fixed to the inner wall of the sealed case 1 and a bearing 13 attached to the bearing bracket 12.

FIG. 2 is a perspective view schematically showing the bearing bracket 12 and the bearing 13. The outer periphery of the bearing bracket 12 is easily fixed by shrink fitting, press fitting, welding, etc. to the inner peripheral wall of the sealed case 1. A plurality of screw holes 1.2b are provided near the inner circumference, and a plurality of holes 12c through which compressed refrigerant gas and the like pass are provided near the outer circumference.

On the other hand, the bearing 13 has a cylindrical bearing part 13a in the center of the disc.
is provided, and the bearing bracket 1 is provided near the outer periphery of the disc.
A hole 13b corresponding to a plurality of screw holes 12b provided near the inner circumference of the hole 2 and a hole 13c for passing compressed refrigerant gas etc. are provided. 12b, and rotatably supports the rotating shaft 4 of the motor 2.

Since the third bearing 11 is thus divided into the bearing bracket 12 and the bearing 13, it can be easily attached to the sealed case 1, and the positional relationship between the rotating shaft 4 and the bearing 13 can be fixed with high accuracy.

〔Effect of the invention〕

As explained above, if the compressor is equipped with the third bearing, the shaking of the rotating shaft will be suppressed, and the bending and deformation of the rotating shaft will be reduced, so large vibrations will be generated even during high-speed rotation. With the reduction of the surface deformation, there is no need to use highly rigid and expensive materials, and since the bearing has a two-piece structure, it is easy to assemble. Mechanical precision can also be easily increased.

[Brief explanation of drawings]

Fig. 1 is a vertical side view of a rotary compressor showing an embodiment of the present invention, Fig. 2 is a perspective view of essential parts of the same embodiment, and Fig. 3 is a longitudinal side view of a rotary compressor showing a conventional example. It is. In the figure, 1--1 sealed case, 2=-motor, 3-peripheral constant, 4=rotating shaft, 5=rotor, 6-upper balancer, 7-lower balancer, 8-compression device, 9-first bearing, 10-second bearing, 11-third bearing, 12-bearing bracket I.
, 12a - outer periphery, 1.2b - screw hole, 12c hole, l
3-bearing, 1.3a-bearing part, 13b-hole, 13c hole, 14-screw.

Claims (3)

[Claims] (1) A motor is installed in the upper part of the sealed case, and a compression device is installed in the lower part to compress the refrigerant as the motor rotates.
In a rotary compressor, a rotary shaft of the motor is rotatably supported by first and second bearings formed on an upper surface and a lower surface of the compressor, the rotary shaft of the motor is supported by the same rotary shaft. A rotary compressor, comprising: a third bearing that protrudes from the upper surface of a rotor fixed to the rotor, and rotatably supports the protruding rotating shaft. (2) The rotary compressor according to claim 1, wherein the third bearing is divided into a ring-shaped bearing bracket fixed to the inner wall of the sealed case and a bearing attached to the bearing bracket. (3) The rotary compressor according to claim 1 or 2, wherein one or both of the bearing bracket and the bearing constituting the third bearing are provided with a passage hole for compressed refrigerant gas or the like.