Patent ID: 7287969
Filing Date: 2007-10-30
Classification: F03C,F04C

Abstract:
1. A rotary fluid pressure device of the type including a housing defining a fluid inlet and a fluid outlet; a rotary fluid displacement mechanism including an output member having one of orbital and rotational movement; said device including an output shaft extending axially relative to said output member and operable to transmit said movement of said output member; said housing defining a generally cylindrical brake chamber, and a piston member disposed in said brake chamber, said piston member being moveable between a first, retracted position under the influence of fluid pressure in said brake chamber, and a second engaged position under the influence of a biasing spring disposed in engagement with a rearward side of said piston member; and braking means operably associated with said piston member and one of said output member and said output shaft, such that movement of said piston member to said second, engaged position results in braking of said output shaft; characterized by: (a) said housing defining a fluid pressure port in fluid communication with said fluid inlet; (b) a first area of said piston member defining at least a portion of a first pressure release chamber that is in fluid communication with said fluid pressure port; (c) a second area of said piston member defining at least a portion of a second pressure release chamber that is in fluid communication with said fluid pressure port, wherein said second area is less than said first area; (d) valve means operable, wherein fluid pressure in said first pressure release chamber reaches a predetermined pressure, to communicate said first pressure chamber to a source of low pressure fluid.