PURPOSE: To reduce a cut-off wrap angle for enhancing the compression ratio of a scroll type fluid device, and to miniaturize the device by reducing the outside diameter of the scroll.
CONSTITUTION: A scroll type fluid device is provided with a pair of fixed scrolls 5a, 5b, a turning scroll 60 arranged between both the fixed scrolls 5a, 5b, and a crankshaft penetrating through the respective scrolls 5a, 5b, and 60. The inner circumferential surface of the lap 52 of the fixed scroll 5a or 5b is made up of an inner circumferential circular-arc surface 55 that has been formed at the starting end and an inner circumferential involute surface 56 that is continued to the inner circumferential circular-arc surface 55. The outer circumferential surface of the lap 62 of the turning scroll 60 is made up of an outer circumferential circular-arc surface 67 that has been formed at the starting end, and an outer circumferential involute surface 68 that is continued to the outer circumferential circular-arc surface 67. On the other hand, the eccentric part of the crankshaft is formed so as to have a smaller diameter than that of the shaft body, and to the shaft body a communicating passage that is opened to the end surface and is capable of being communicated with the operation chamber is formed.
KOSHO KAZUHIRO
YAMAJI HIROYUKI
FUKUNAGA TAKESHI
