Hermetic reciprocating compressor with thrust ball bearing

Abstract

A hermetic compressor includes a hermetic container that stores lubricating oil, an electrically-driven element having a stator and a rotor, a shaft having a compressing element driven by the electrically-driven element, and including an eccentric shaft portion, a cylinder block, a piston, a coupling device that connects the piston and the eccentric shaft portion, a main bearing, and a thrust ball bearing that supports a vertical load by the self weight of the rotor and the shaft. The thrust ball bearing includes a plurality of balls having a diameter of 3 mm or less, a holder portion holding the balls and formed of a polymeric material, and an upper washer and a lower washer disposed above and below the balls, respectively, and the viscosity grade of the lubricating oil is from ISO VG3 to ISO VG10.

Description

TECHNICAL FIELD[0001]The present invention relates to a hermetic compressor used for a refrigerating cycle of a freezing refrigerator, etc.BACKGROUND ART[0002]In recent years, as for a hermetic compressor used for a freezer of a freezing refrigerator, etc., attainment of high efficiency for reduction of power consumption is advanced. Conventionally, as a means for attaining the high efficiency of the hermetic compressor, a thrust ball bearing in which the sliding loss of a thrust bearing portion is reduced compared with a sliding bearing has been adopted. Meanwhile, lowering of viscosity of lubricating oil is advanced in order to reduce the sliding loss.[0003]As this type of conventional hermetic compressor, there is one in which upper and lower portions of a ball is sandwiched by a washer, and a thrust ball bearing of an inexpensive and simple configuration using a cage made of a polymeric material is used to attain high efficiency (for example, refer to Patent Document 1).[0004]He...

AI Technical Summary

Benefits of technology

[0019]According to the hermetic compressor having such a configuration, the balls are made light to reduce the centrifugal force, consequently to reduce the surface pressure applied to the holder portion. By using the holder portion under a surface pressure lower than a sliding limit of a polymeric material, the effect of reducing the sliding loss of a thrust bearing portion can be maintained, the wear of holder portion can be prevented even if the high efficiency is attained using a lubricating oil of low viscosity. As a result, a hermetic compressor that is highly efficient and highly reliable can be provided.

Problems solved by technology

However, in the conventional configuration, there is a problem that cage 31 may worn out and reliability may be lowered, in a case where lubricating oil 6 of low viscosity grade like ISO VG3 to ISO VG10 is used.

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