Viscous fluid clutch

Claim 2

A viscous fluid clutch comprising first and second relatively rotatable drive means, said first drive means having an annular operating chamber and a reservoir chamber, fluid shear drive means on said first and second drive means located in said operating chamber forming a shear space therebetween and operable with a fluid to provide a shear-type fluid drive between said first and second drive means, said operating chamber having outlet-opening means at an outer portion and inlet-opening means at an inner portion, pump means on one of said drive means to pump fluid from said operating chamber through said outletopening means to said reservoir chamber, and passage means formed through said second drive means and transversely across a portion of said fluid shear drive means and terminating at a point adjacent and radially inward of the outer edge of said second drive means for causing said fluid flowing from said reservoir chamber through said inlet opening means into said operating chamber to fill said shear space between said fluid shear drive means on said first and second relatively rotatable drive means at a predetermined temperature.

Claim 3

A viscous fluid clutch comprising first and second relatively rotatable drive members, said first drive member including a first wall, a second wall and a divider wall sealed between said first and second walls providing a working Chamber between said divider and second walls and a second chamber between said first and divider walls, fluid shear drive means on said first and second drive members in said working chamber operable with a fluid medium having a viscosity of up to 9,000 centistokes and beyond to provide a shear-type fluid drive therebetween, first opening means in said divider wall for providing communication from said working chamber to said second chamber, pump means on one of said drive members for causing said fluid medium to flow from said working chamber through said first opening means to said second chamber, second opening means formed in said divider wall for communicating said fluid medium from said second chamber to said working chamber, and radially extending circulation means on one of said drive members and having an open inner portion and a closed outer portion for causing said fluid medium to fill said shear-type fluid drive portion of said working chamber and bring said first drive member up to maximum speed at a predetermined ambient temperature.

Claim 4

A viscous fluid clutch comprising first and second relatively rotatable drive members, said first drive member including a first wall, a second wall and a divider wall sealed between said first and second walls providing a working Chamber between said divider and second walls and a second chamber between said first and divider walls, fluid shear drive means on said first and second drive members in said working chamber operable with a fluid medium having a viscosity of up to 9,000 centistokes and beyond to provide a shear-type fluid drive therebetween, first opening means in said divider wall for providing communication from said working chamber to said second chamber, pump means on one of said drive members for causing said fluid medium to flow from said working chamber through said first opening means to said second chamber, second opening means formed in said divider wall for communicating said fluid medium from said second chamber to said working chamber, and radially extending circulation means on one of said drive members and having an open inner portion and a closed outer portion for causing said fluid medium to fill said shear-type fluid drive portion of said working chamber and bring said first drive member up to maximum speed at a predetermined ambient temperature.

Claim 5

A viscous fluid clutch comprising first and second relatively rotatable drive means, said first drive means having an annular operating chamber and a reservoir chamber, a plurality of annular ridges formed on one of said first and second drive means and a plurality of cooperating annular grooves formed on the other of said first and second drive means in said operating chamber, said annular ridges and grooves forming a shear space operable with a fluid to provide a shear-type fluid drive between said first and second drive means, said operating chamber having outlet-opening means at an outer portion and inlet-opening means at an inner portion, pump means on one of said drive means to pump fluid from said operating chamber through said outlet-opening means to said reservoir chamber, opening means formed through said second drive means and dead ended groove means formed on the fluid shear drive side of said second drive means for receiving fluid from said reservoir chamber through said inlet opening means and said last-mentioned opening means and causing said fluid to flow circumferentially into said annular grooves to fill said shear space.

Claim 6

A viscous fluid clutch comprising first and second relatively rotatable drive means, said first drive means having an annular operating chamber and a reservoir chamber, a plurality of annular ridges formed on one of said first and second drive means and a plurality of cooperating annular grooves formed on the other of said first and second drive means in said operating chamber, said annular ridges and grooves forming a shear space operable with a fluid to provide a shear-type fluid drive between said first and second drive means, said operating chamber having outlet-opening means at an outer portion and inlet-opening means at an inner portion, pump means on one of said drive means to pump fluid from said operating chamber through said outlet-opening means to said reservoir chamber, opening means formed through said second drive means and dead ended groove means formed on the fluid shear drive side of said second drive means for receiving fluid from said reservoir chamber through said inlet opening means and said last-mentioned opening means and causing said fluid to flow circumferentially into said annular grooves to fill said shear space.

Claim 7

A viscous fluid clutch comprising first and second relatively rotatable drive members, said first drive member including front and rear walls and defining a fluid cavity therebetween, a divider wall sealed between said front and rear walls in said fluid cavity and dividing said fluid cavity into first and second chambers, said second drive member being rotatable in said first chamber, said second drive member and said rear wall having opposed spaced parallel surfaces defining a fluid shear space therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive therebetween, a first opening formed in said divider wall for providing communication between said first chamber and said second chamber, a dam element formed on said divider wall in said first chamber adjacent said first opening for causing said fluid medium to flow through said first opening for varying the volume of fluid medium in said shear space to vary the torque transmitted between said first and second drive members, a second opening formed in said divider wall for at times communicating said fluid medium from said second chamber to said first chamber, valve means for controlling the flow of said fluid medium through said second opening to further vary the torque transmitted between said first and second drive members, at least one radial groove formed on said second drive member transverse said spaced parallel surfaces, said at least one radial groove having a closed outer end and an open inner end, and a plurality of openings formed in said second drive member and located on a circle radially inward of said at least one radial groove.

Claim 8

A viscous fluid clutch comprising first and second relatively rotatable drive members, said first drive member including front and rear walls and defining a fluid cavity therebetween, a divider wall sealed between said front and rear walls in said fluid cavity and dividing said fluid cavity into first and second chambers, said second drive member being rotatable in said first chamber, said second drive member and said rear wall having opposed spaced parallel surfaces defining a fluid shear space therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive therebetween, a first opening formed in said divider wall for providing communication between said first chamber and said second chamber, a dam element formed on said divider wall in said first chamber adjacent said first opening for causing said fluid medium to flow through said first opening for varying the volume of fluid medium in said shear space to vary the torque transmitted between said first and second drive members, a second opening formed in said divider wall for at times communicating said fluid medium from said second chamber to said first chamber, valve means for controlling the flow of said fluid medium through said second opening to further vary the torque transmitted between said first and second drive members, at least one radial groove formed on said second drive member transverse said spaced parallel surfaces, said at least one radial groove having a closed outer end and an open inner end, and a plurality of openings formed in said second drive member and located on a circle radially inward of said at least one radial groove.

Claim 9

The viscous fluid clutch described in claim 4, and bimetallic thermostat means for actuating said valve means.

Claim 10

A viscous clutch comprising first and second relatively rotatable drive members, said first drive member including a first wall, a second wall and a divider wall sealed between said first and second walls providing a working chamber between said divider and second walls and a second chamber between said first and divider walls, fluid shear drive means on said first and second drive members in said working chamber operable with a fluid medium to provide a shear-type fluid drive therebetween, first opening means in said divider wall for providing communication from said working chamber to said second chamber, pump means on one of said drive members in cooperation with said rotating second drive member for causing said fluid medium to flow from said working chamber through said first opening means to said second chamber, ambient temperature-responsive opening means formed in said divider wall for communicating said fluid medium from said second chamber to said working chamber on the side of said second drive member adjacent said divider wall, a plurality of openings formed in said second drive member equidistant from the center thereof for permitting said fluid medium to spill over from said side of said second drive member adjacent said divider wall to said shear-type fluid drive side of said first drive member, and a plurality of radial grooves formed transversely through said fluid shear drive means on one of said drive members and having their inner ends adjacent the circle of radial outer edges of said equidistant openings and their outer ends closed within the outer edge of said second drive member for receiving said fluid medium spilled through said equidistant openings and filling the shear-type fluid drive space between said fluid shear drive means.

Claim 11

A viscous clutch comprising first and second relatively rotatable drive members, said first drive member including a first wall, a second wall and a divider wall sealed between said first and second walls providing a working chamber between said divider and second walls and a second chamber between said first and divider walls, fluid shear drive means on said first and second drive members in said working chamber operable with a fluid medium to provide a shear-type fluid drive therebetween, first opening means in said divider wall for providing communication from said working chamber to said second chamber, pump means on one of said drive members in cooperation with said rotating second drive member for causing said fluid medium to flow from said working chamber through said first opening means to said second chamber, ambient temperature-responsive opening means formed in said divider wall for communicating said fluid medium from said second chamber to said working chamber on the side of said second drive member adjacent said divider wall, a plurality of openings formed in said second drive member equidistant from the center thereof for permitting said fluid medium to spill over from said side of said second drive member adjacent said divider wall to said shear-type fluid drive side of said first drive member, and a plurality of radial grooves formed transversely through said fluid shear drive means on one of said drive members and having their inner ends adjacent the circle of radial outer edges of said equidistant openings and their outer ends closed within the outer edge of said second drive member for receiving said fluid medium spilled through said equidistant openings and filling the shear-type fluid drive space between said fluid shear drive means.

Claim 12

A viscous clutch comprising first and second relatively rotatable drive members, said first drive member including a first wall, a second wall and a divider wall sealed between said first and second walls providing a working chamber between said divider and second walls and a second chamber between said first and divider walls, fluid shear drive means on said first and second drive members in said working chamber operable with a fluid medium to provide a shear-type fluid drive therebetween, first opening means formed adjacent an outer edge of said divider wall for providing communication from said working chamber to said second chamber, second opening means formed in said second drive member on the same circle as said first opening means, a radial groove formed in said second drive member terminating at said second opening means, pump means on one of said drive members in cooperation with said second opening means and said radial groove for causing said fluid medium to flow from said working chamber through said first opening means to said second chamber, ambient temperature-responsive opening means formed in said divider wall for communicating said fluid medium from said second chamber to said working chamber on the side of said second drive member adjacent said divider wall, a plurality of openings formed in said second drive member equidistant from the center thereof for permitting said fluid medium to spill over from said side of said second drive member adjacent said divider wall to said shear-type fluid drive side of said second drive member, and a plurality of radial recesses formed transversely through said fluid shear drive means radially outwardly of said plurality of openings in said second drive member and having their outer ends closed within the outer edge of said second drive member for receiving said fluid medium spilled through said equidistant openings and filling the shear-type fluid drive space between said fluid shear drive means.

Claim 13

A viscous clutch comprising first and second relatively rotatable drive members, said first drive member including a first wall, a second wall and a divider wall sealed between said first and second walls providing a working chamber between said divider and second walls and a second chamber between said first and divider walls, fluid shear drive means on said first and second drive members in said working chamber operable with a fluid medium to provide a shear-type fluid drive therebetween, first opening means formed adjacent an outer edge of said divider wall for providing communication from said working chamber to said second chamber, second opening means formed in said second drive member on the same circle as said first opening means, a radial groove formed in said second drive member terminating at said second opening means, pump means on one of said drive members in cooperation with said second opening means and said radial groove for causing said fluid medium to flow from said working chamber through said first opening means to said second chamber, ambient temperature-responsive opening means formed in said divider wall for communicating said fluid medium from said second chamber to said working chamber on the side of said second drive member adjacent said divider wall, a plurality of openings formed in said second drive member equidistant from the center thereof for permitting said fluid medium to spill over from said side of said second drive member adjacent said divider wall to said shear-type fluid drive side of said second drive member, and a plurality of radial recesses formed transversely through said fluid shear drive means radially outwardly of said plurality of openings in said second drive member and having their outer ends closed within the outer edge of said second drive member for receiving said fluid medium spilled through said equidistant openings and filling the shear-type fluid drive space between said fluid shear drive means.