JPH04237887A - Hermetic motor compressor - Google Patents

Abstract

PURPOSE:To facilitate a job for assembly operability and working properties by improving the life and reliability of a ball bearing in the case where it is used, while promoting the stabilization of motor efficiency, and assembling a connecting rod without splitting it, in such a case pertaining to the promotion of efficiency in an enclosed motor compressor available for a refrigerator, etc. CONSTITUTION:This compressor consists of a crank journal 20, an eccentric shaft 21, a ball bearing 24 installed more at the opposite side of a motor element 2 than at the axis of a cylinder 13 and on the same axial center as a shaft center of the crank journal 20, a spacer 25 pressed in an inner ring of the ball bearing 24 and an eccentric hole 26 installed in this spacer 25.

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. 4 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.

[0007] Similarly, the ball bearing 8 is subject to a large load. Therefore, ball bearings 7, 8
This leads to a reduction in the service life of the product, making it difficult to ensure reliability. Further, due to the radial clearance between the ball bearings 7 and 8, the clearance between the stator 4 and the rotor 5 becomes unstable, resulting in a decrease in motor efficiency. In addition, in order to reduce the load due to compressive load, the electric element 2 side (
Sometimes measures are taken to support the crankshaft on both sides (referred to as the main shaft side) and the counter-motorized element 2 side (referred to as the countershaft side), but it is necessary to process both the main shaft and the countershaft, and the main shaft And complex machining is required to achieve coaxiality of the sub-shaft.

Furthermore, since it has a subshaft, in order to downsize the compressor, the connecting rod cannot be assembled as one piece due to its structure, but must be divided, which results in poor workability and complicated machining.

In view of the above-mentioned problems, the present invention reduces the load on the ball bearing to increase its life and reliability, stabilizes the gap size between the stator and rotor, stabilizes the efficiency, and further reduces the assembly work. The present invention provides a compressor with good performance and easy processing.

0010

Means for Solving the Problems In order to solve the above problems, a compressor of the present invention is provided with ball bearings that pivotally support a crank main shaft and an eccentric shaft, and one of the ball bearings is connected to a cylinder of a compression element. A spacer is inserted into the inner ring of the ball bearing, and the spacer is arranged on the opposite side of the axis of the crankshaft and on the same axis as the axis of the crank main shaft. The eccentric shaft is inserted into the hole, and the eccentric shaft is inserted into the hole.

[0011] Furthermore, the eccentric shaft may be loosely fitted into the hole.

0012

[Operation] With the above-described configuration, the present invention reduces the load on the ball bearing to increase its life and reliability, stabilizes the gap between the stator and rotor, stabilizes efficiency, and further improves the assembly work. It has good properties and can be easily processed.

[0013]

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 FIGS. 1 and 2, 20 is a crank main shaft, and an eccentric shaft 21 is integrally formed by casting or forging. Reference numeral 22 denotes an integrally molded connecting rod, one end of which is 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 20.

Reference numeral 24 denotes a ball bearing, which is located on the side opposite to the electric element 2 from the axis of the cylinder 13 and is mounted coaxially with the axis of the crank main shaft 20. A spacer 25 is press-fitted into the inner ring of the ball bearing 24. 26 is a hole provided in the spacer 25, and is provided at a position eccentric to the axis of the ball bearing 24, and the amount of eccentricity is the same as the amount of deviation between the axes of the crank main shaft 20 and the eccentric shaft 21. is loosely fitted.

In the above configuration, since the ball bearings 23 and 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 piston 12
The ball bearings 23 and 24 receive the load due to the reaction caused by the compressive load almost equally, and the load on the ball bearings 23 and 24 can be reduced. Therefore, the life and reliability of the ball bearings 23 and 24 can be increased.

Furthermore, the mounting interval between the ball bearings 23 and 24 can be made longer than in the conventional example, and the variation in the gap size between the stator 4 and the rotor 5 due to the influence of the radial gap between the ball bearings 23 and 24 can be reduced. can be reduced and the efficiency of the motor can be stabilized. In addition, since the crank main shaft 20 and the eccentric shaft 21 are integrally molded and do not have a sub-crank shaft, machining is easy.Furthermore, the connecting rod 22 can be assembled to the eccentric shaft 21 without being divided, which improves assembly workability. It is easy to process the connecting rod 22.

Furthermore, a spacer 2 is attached to the ball bearing 24.
After press-fitting the hole 26 into the eccentric shaft 21, the assembly work becomes easier.

[0019]

[Effects of the Invention] As described above, according to the compressor of the present invention,
two ball bearings that pivotally support a crank main shaft and an eccentric shaft, one of the ball bearings being placed on the side opposite to the electric element from the axis of the cylinder of the compression element and coaxially with the axis of the crank main shaft. A spacer is inserted into the inner ring of the ball bearing, a hole is provided in the spacer eccentric to the axis of the ball bearing, and the eccentric shaft is inserted into the hole. , the load on the ball bearing can be reduced, and the life and reliability of the ball bearing can be increased. Furthermore, the distance between the two ball bearings can be increased, and fluctuations in the gap size between the stator and rotor can be reduced, so motor efficiency can be stabilized. Furthermore, the connecting rod does not need to be divided and can be assembled as a single piece, resulting in good workability and easy machining.

[0020] In addition, by loosely fitting the eccentric shaft into the hole provided in the spacer, assembly work is facilitated, and furthermore, since tolerances in hole diameter and hole position can be made large, machining is also facilitated. Effects can be obtained.

[Brief explanation of the drawing]

[Fig. 1] Side cross-sectional view of a hermetic electric compressor in one embodiment of the present invention.

[Fig. 2] A plan view of the main part of the cross section taken along the line A-A in Fig. 1.

[Figure 3] Side sectional view of a conventional compressor

[Figure 4] 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 13 Cylinder 20 Crank main shaft 21 Eccentric shaft 23 Ball bearing 24 Ball bearing 25 Spacer 26 hole

Claims (2)

[Claims] 1. An electric element and a compression element elastically supported in a closed container, a crank main shaft fixed to a rotor of the electric element, an eccentric shaft provided on the crank main shaft, and the crank main shaft and the eccentric shaft. a ball bearing that pivotally supports a shaft, one of the ball bearings being disposed on the side opposite to the electric element from the axis of the cylinder of the compression element and coaxially with the axis of the crank main shaft; A hermetic electric compressor, characterized in that a spacer is inserted into the inner ring of the ball bearing, a hole eccentric to the axis of the ball bearing is provided in the spacer, and the eccentric shaft is inserted into the hole. 2. The hermetic electric compressor according to claim 1, wherein the eccentric shaft is loosely fitted into the hole.