JPH04308373A - Closed-type motor-driven compressor - Google Patents

Abstract

PURPOSE:To prolong the life of a ball bearing and heighten its reliability in the case of using the ball bearing regarding the high efficiency of a closed-type motor-driven compressor used for a refrigerator or the like, and facilitate assembling work performance and reduce the number of parts by applying pre-load to the ball bearing without using another means. CONSTITUTION:A closed-type motor-driven compressor is formed of a master crankshaft 20a, an auxiliary crankshaft 20b, a ball bearing 23 press-fitted to the master crankshaft 20a, a sliding bearing 24 with the auxiliary crankshaft 20b fitted thereto, and a housing 25 with which the outer wheel 23a of the ball bearing 23 is brought into contact.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic electric compressor used in refrigerators and the like.

0002

BACKGROUND OF THE INVENTION In recent years, there has been a demand for higher efficiency of hermetic electric compressors (hereinafter referred to as compressors) from the standpoint of improving energy efficiency. Compressors have become highly efficient and have reached a high level, but we must strive for even higher efficiency.

An example of a conventional compressor will be described below with reference to the drawings. FIG. 2 is a side sectional view of a compressor disclosed in Japanese Patent Application Laid-Open No. 63-5186. 1 is a closed container which elastically supports an electric element 2 and a compression element 3. The electric element 2 includes a stator 4, a rotor 5, and a crank main shaft 6 fitted into the rotor 5.

Ball bearings 7 and 8 are attached to the upper and lower ends of a bearing 9 that supports the crankshaft 6. Reference numeral 10 denotes an eccentric shaft integrally molded with the crankshaft 6, into which one end of a connecting rod 11 is fitted. A piston 12 is connected to the other end of the connecting rod 11 and is fitted into the cylinder 13.

[0005] In the compressor configured as above,
When the compressor starts operating, the rotor 5 rotates, which causes the crank main shaft 6 to rotate via ball bearings 7 and 8, and the piston 12 to rotate via the eccentric shaft 10 and connecting rod 11.
reciprocates within the cylinder 13 to compress the gas.

[0006]

[Problems to be Solved by the Invention] However, in the above-mentioned configuration, the piston 12 is supported on one side of the shaft in the compression direction (cantilevered structure), so the compression effect is affected by the action of the moment, as shown in FIG. The load acting on the ball bearing 7 against the reaction W becomes W·L/K, which is larger than W. Further, the ball bearing 8 is similarly subjected to a large load.

[0007] Therefore, the life of the ball bearings 7 and 8 is shortened, and it is difficult to ensure reliability. In addition, it is necessary to apply preload to the ball bearings 7 and 8 in order to improve reliability and reduce noise. Due to the structure, one ball bearing is preloaded due to the weight of the compression element, but the other ball bearing is not. It is necessary to apply preload using the means described above, which results in poor workability and an increase in the number of parts.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a compressor that reduces the load on ball bearings, increases lifespan and reliability, and has good assembly workability and a reduced number of parts.

[0009]

[Means for Solving the Problems] In order to solve the above problems, the compressor of the present invention includes an electric element and a compression element elastically supported in a closed container, and a crankshaft fixed to the rotor of the electric element. and an eccentric shaft provided on the crankshaft, the crankshaft having a crank main shaft and a crank subshaft on both sides of the eccentric shaft in the axial direction, and a ball bearing on either the crank main shaft or the crank subshaft. It has a configuration in which the following are arranged.

0010

[Operation] With the above-described structure, the present invention can reduce the load on the ball bearing to increase its life and reliability, improve assembly workability, and reduce the number of parts.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A compressor according to an embodiment of the present invention will be described below with reference to the drawings. Note that the same reference numerals are used for the same configurations as those of the conventional example, and detailed explanation thereof will be omitted.

In FIG. 1, a crankshaft 20 has a crank main shaft 20a, a crank subshaft 20b, and an eccentric shaft 21. A connecting rod 22 has one end fitted into the eccentric shaft 21 and the other end connected to the piston 12.

A ball bearing 23 is located on the electric element 2 side with respect to the axis of the cylinder 13, and is press-fitted and fixed to the crank main shaft 20a. 24 is a sliding bearing located on the side opposite to the electric element 2 from the axis of the cylinder 13, into which the crank subshaft 20b is fitted. 25 is a housing into which the outer ring 23a of the ball bearing 23 is inserted, and the weight of the crankshaft 20 and rotor 5 is absorbed by the housing 25 and the outer ring 2.
It is supported by the contact surface 26 of 3a.

In the above configuration, since the ball bearing 23 and the slide bearing 24 are arranged on the electric element 2 side and the non-electric element 2 side with respect to the axis of the cylinder 13, the reaction due to the compressive load of the piston 12 The load is received almost equally by the ball bearing 23 and the slide bearing 24, and the load applied to the ball bearing 23 can be reduced. Therefore, the life and reliability of the ball bearing 23 can be increased.

Furthermore, it is necessary to apply preload to the ball bearing 23 in order to improve reliability and reduce noise, but since the outer ring 23a of the ball bearing 23 supports the weight of the crankshaft 20 and rotor 5, it is structurally difficult. ball bearing 2
3 is preloaded, so there is no need to use a separate part to apply preload, making assembly easier and reducing the number of parts.

[0016]

[Effects of the Invention] As described above, according to the compressor of the present invention,
It includes an electric element and a compression element elastically supported in a closed container, a crankshaft fixed to a rotor of the electric element, and an eccentric shaft provided on the crankshaft, the crankshaft having an axis line of the eccentric shaft. A crank main shaft and a crank sub-shaft are provided on both sides in the direction, and a ball bearing is disposed on one of the crank main shaft and crank sub-shaft, thereby reducing the load on the ball bearing. can extend the life of ball bearings,
Reliability can be increased. Further, since preload can be applied to the ball bearing without using any special means, workability is improved and the number of parts is reduced.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a compressor in one embodiment of the present invention.

[Figure 2] Side sectional view of a conventional compressor

[Figure 3] Schematic diagram of the load applied to the crank shaft of a conventional compressor

[Explanation of symbols]

1　Airtight container 2　Electric element 3 Compression element 5 Rotor 20 Crankshaft 20a Crank main shaft 20b Crank subshaft 21 Eccentric shaft 23 Ball bearing

Claims (1)

[Claims] 1. A motor-driven element comprising an electric element and a compression element elastically supported in a closed container, a crankshaft fixed to a rotor of the electric element, and an eccentric shaft provided on the crankshaft, the crankshaft being A hermetic electric compressor, characterized in that the eccentric shaft has a crank main shaft and a crank subshaft on both sides in the axial direction, and a ball bearing is disposed on either the crank main shaft or the crank subshaft.