Scroll fluid machine

Abstract

A scroll fluid machine includes a pair of a fixed scroll ( 15 ) and an orbiting scroll ( 16 ). The scroll fluid machine has an one-side stepped scroll structure in which a stepped part ( 16 E) is provided only at a predetermined position on a tooth bottom surface ( 16 D) of a involute spiral wrap ( 16 B) of one of the fixed scroll ( 15 ) and the orbiting scroll ( 16 ) in a spiral direction, and a stepped part ( 15 E) corresponding to the stepped part ( 16 E) on the tooth bottom surface ( 16 D) is provided only at a predetermined position on a tooth top surface ( 15 C) of a involute spiral wrap ( 15 B) of the other scroll in a spiral direction. The stepped part ( 16 E) on the tooth bottom surface ( 16 D) is provided at a position on an inner side of a spiral end position ( 16 F) of the involute spiral wrap ( 16 B) at intake closure by an involute angle of n radians in the spiral direction or at a position on an outer side of the inner-side position.

1 . A scroll fluid machine comprising a pair of a fixed scroll and an orbiting scroll that include respective involute spiral wraps erected on end plates and meshed with each other in a facing manner,
 the scroll fluid machine having a one-side stepped scroll structure in which a stepped part is provided only at a predetermined position on a tooth bottom surface of the involute spiral wrap of one of the fixed scroll and the orbiting scroll in a spiral direction, and a stepped part corresponding to the stepped part of the tooth bottom surface is provided only at a predetermined position on a tooth top surface of the involute spiral wrap of the other scroll in a spiral direction,   wherein the stepped part on the tooth bottom surface is provided at a position on an inner side of a spiral end position of the corresponding involute spiral wrap at intake closure by an involute angle of π radians in the spiral direction or at a position on an outer side of the inner-side position.   
     
     
         2 . A scroll fluid machine comprising a pair of a fixed scroll and an orbiting scroll that include respective involute spiral wraps erected on end plates and meshed with each other in a facing manner,
 the scroll fluid machine having a both-side stepped scroll structure in which stepped parts are provided at predetermined positions on a tooth top surface and a tooth bottom surface of the involute spiral wrap of each of the fixed scroll and the orbiting scroll in a spiral direction,   wherein the stepped parts have heights different between the fixed scroll and the orbiting scroll, and the stepped part on each tooth bottom surface is provided at a position on an inner side of a spiral end position of the corresponding involute spiral wrap at intake closure by an involute angle of π radians in a spiral direction or at a position on an outer side of the inner-side position.   
     
     
         3 . The scroll fluid machine according to  claim 1 , wherein the stepped part on the tooth bottom surface is provided in a positional range on the inner side of the spiral end position of the corresponding involute spiral wrap by an involute angle of π/2 radians to π radians in the spiral direction. 
     
     
         4 . The scroll fluid machine according to  claim 2 , wherein the stepped part on the tooth bottom surface is provided in a positional range on the inner side of the spiral end position of the corresponding involute spiral wrap by an involute angle of π/2 radians to π radians in the spiral direction.