Abstract: A scrool fluid machine including a fixed scroll an orbiting scroll an Oldham ring and bearing portions which are entirely or partly made of a reaction-bonded precise sintered ceramics which is superior in near-net-shape property, and particularly made of a reaction bonded precise sintered ceramics which is produced by reaction-bonding inorganic compound particles such as A1.sub.2 O.sub.3, SiC, TiN, ZrN etc. with Si.sub.3 N.sub.4 which is a nitride of Si.

Abstract: A hermetic motor compressor for compressing refrigerant gas in air conditioners or refrigerators. The hermetic motor compressor includes a motor compressor disposed in a closed housing and consisting of a motor section and a compressor section formed integrally with each other. The compressor section has a cylinder head cover, discharge silencer and discharge tube through which the compressed refrigerant gas is discharged to the outside. The cylinder head cover, discharge silencer and discharge tube are covered by heat insulating members with suitable spaces provided therearound. Heat radiation from the discharge system is therefore prevented by the spaces as well as by the heat insulating members, so that the temperature rise of refrigerant gas in the closed housing is avoided to ensure a higher volumetric efficiency of the compressor.