Hitachi, Ltd.

Yasuhiro Ohshima

Masahiro Takebayashi

Hirokatsu Kohsokabe

Shunichi Mitsuya

Kenji Tojo

Hiroaki Hata

Shigetaro Tagawa

Takeshi Kouno

Kingo Moriyama

A displacement type fluid machine has a sliding contact portion between a cylinder and a displacer made into a predetermined section, and the cylinder and the displacer so contoured that when they are made concentric, the normal distance in the sliding contact section between the cylinder contour and the displacer contour may be smaller than that of the remaining section, thereby to decrease the radial gap to lower the internal leakage of the working fluid and to improve the performance and the reliability.

Displacement type fluid machine

In a displacement type fluid machine wherein a space is formed by the inner wall surface of a cylinder and the outer wall surface of a displacer when the center of the cylinder is located on the center of the displacer, and a plurality of working chambers is formed when the positional relationship between the displacer and cylinder is for a gyration, the wear is reduced between the cylinder and displacer. Sliding portions between the displacer,and a cylinder,are fed with a lubricating oil,by forming an oil-feeding groove,in the surface of the displacer,so as to extend from the central portion of the displacer,to the vicinity of a suction port,, and feeding the lubricating oil,from the central portion of the displacer,, so that the wear can be reduced.

A conventional displacement type fluid machine is featured by a low sliding rate and in low vibrations and pulsations, but has a problem, that the radial gap in a displacer sliding portion is enlarged by the clearance of a shaft drive system and a rotating moment acting on a displacer so that the internal leakage of a working fluid is increased to lower the performance and the reliability. To eliminate this problem, the sliding contact portion between a cylinder,and a displacer,is made into a predetermined section, and the cylinder and the displacer are so contoured that when they are made concentric, the normal distance in the sliding contact section between the cylinder contour and the displacer contour may be smaller than that of the remaining section, thereby to decrease the radial gap to lower the internal leakage of the working fluid and to improve the performance and the reliability.

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Tochigi-ken, Japan

Yasuhiro Ohshima