Patent ID: 6699024
Filing Date: 2004-03-02
Classification: F03C,F04C

Abstract:
A hydraulic motor comprising:an end cover, which includes a first port and a second port; a drive link; a drive assembly; a flow circuit between the first port and the second port; a coupling shaft, which is connected to the drive link; a shaft housing, which rotatably supports the coupling shaft; and a plurality of clamping members extending through registered openings in the end cover, the drive assembly, and the shaft housing to clamp them together; wherein the flow circuit comprises a working path that causes the drive assembly to hypocycloidally move the drive link in a first direction when fluid passes from the first port to the second port through the working path, and that causes the drive assembly to hypocycloidally move the drive link in a second opposite direction when fluid passes from the second port to the first port through the working path; and wherein the working path is axially confined to a length substantially between the end cover and the drive assembly; wherein the flow circuit defines a cylindrical pressure vessel containing the working path; wherein the clamping members are positioned outside of the pressure vessel; wherein a sealing ring seals an interface between the end cover and a movable member of the drive assembly, the member has a groove in which the sealing ring is positioned, the sealing ring has a cross-sectional shape, and the groove has a cross-sectional shape larger than the cross-sectional shape of the sealing ring whereby the sealing ring is movable within the groove in response to fluid pressure; wherein an axial stop for the drive link is positioned within a part of the drive assembly which moves with the drive link; and wherein the flow circuit also comprises a non-working path passing through a chamber surrounding the drive link and wherein: a coupling shaft centrifugally pumps a diverted portion of fluid from the working path through the non-working path back to the working path; or the housing includes a case drain at the end of the non-working path.