Patent ID: 6742638
Filing Date: 2004-06-01
Classification: F16D,F16H

Abstract:
A fluid-operated apparatus for transmitting torque from a rotary output element of a prime mover to a coaxial input element of a driven unit, comprising: a hollow rotary fluid containing housing coaxial with and connected to the output element; a pump connected with and located in said housing; a turbine rotatable with the input element and being located in and rotatable relative to said housing; a bypass clutch disposed in said housing and being engageable to connect said housing with said input element, said clutch including a piston movable axially in and dividing the interior of said housing into a plurality of chambers in the engaged condition of said clutch, a first chamber of said plurality having an inlet and a second chamber of said plurality having an outlet, said piston being movable axially of said housing to engage the clutch in response to an increase of fluid pressure in said first chamber above the fluid pressure in said second chamber; and means for establishing a path for the flow of fluid between said first and second chambers in the engaged condition of said clutch, including a first friction surface borne by said housing, a second friction surface adjacent said first friction surface at least in the engaged condition of said clutch and rotatable with said input element, at least one of said surfaces having a groove communicating with said first and second chambers, defining a first portion of said path and being arranged to offer a pronounced resistance to the flow of fluid therethrough, and at least one throttling orifice defining a second portion of said path, wherein the fluid flows radially inwards from a boundary line between an outside diameter of at least one of the first and second friction surfaces and a neighboring surface and as the fluid flows radially inside from the outside diameter, the flow of the fluid is redirected at least once in the axial direction.