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 formed on oppositely disposed annular portions of 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 outlet opening means to said reservoir chamber, and an annular wear-cushion member mounted radially outwardly of said fluid shear drive means intermediate second oppositely disposed annular portions of said first and second drive means and operatively connected to one of said first and second drive means so as to be rotatable therewith and axially movable relative thereto for minimizing wear on the other of said first and second drive means and cushioning the impact therebetween during relative operational wobble of said first and second drive means.

Claim 3

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, said second drive means being rotatably mounted in said operating 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 therebetween the operable with a fluid to provide a shear-type fluid drive between said first and second drive means, said operating chamber having an 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, and a plurality of longitudinal slots formed at spaced intervals in the surface of said first drive means around the outer periphery of said annular operating chamber and coordinated with the locations of said outlet opening means and said pump means for aiding said pump means to quickly pump said fluid from said operating chamber through said outlet opening means during a cold start operation.

Claim 4

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, said second drive means being rotatably mounted in said operating 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 therebetween the operable with a fluid to provide a shear-type fluid drive between said first and second drive means, said operating chamber having an 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, and a plurality of longitudinal slots formed at spaced intervals in the surface of said first drive means around the outer periphery of said annular operating chamber and coordinated with the locations of said outlet opening means and said pump means for aiding said pump means to quickly pump said fluid from said operating chamber through said outlet opening means during a cold start operation.

Claim 5

The clutch described in claim 1, wherein said wear-cushion member is connected for rotation with said first drive means.

Claim 6

The clutch described in claim 1, wherein said wear-cushion member is connected for rotation with said second drive means.

Claim 7

A viscous fluid clutch comprising first and second relatively rotatable drive members; and first drive member including a first wall, a second wall, 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, and a plurality of longitudinal slots formed therein adjacent said working chamber; fluid shear drive means formed on each of said first and second drive members, at first oppositely disposed annular portions thereof in said working chamber forming a shear space therebetween and a plurality 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 for causing said fluid medium to flow form 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; a wear-cushion member mounted radially outwardly of said fluid shear drive means intermediate second oppositely disposed annular portions of said first and second drive means for minimizing wear on said first and second drive means and preventing contact between said fluid shear drive means during relative operational wobble of said first and second drive means; plurality of protrusions formed on said wear-cushion memBer for being slidably mounted in said longitudinal slots to cause said wear-cushion member to rotate with said first drive member and to permit said wear-cushion member to slide axially relative to said first drive member and thereby permit said fluid medium to provide a fluid shear drive relationship between said wear-cushion member and said second drive member and to provide a cushioning means between said wear-cushion member and said first drive member.

Claim 8

A viscous fluid clutch comprising first and second relatively rotatable drive members; and first drive member including a first wall, a second wall, 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, and a plurality of longitudinal slots formed therein adjacent said working chamber; fluid shear drive means formed on each of said first and second drive members, at first oppositely disposed annular portions thereof in said working chamber forming a shear space therebetween and a plurality 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 for causing said fluid medium to flow form 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; a wear-cushion member mounted radially outwardly of said fluid shear drive means intermediate second oppositely disposed annular portions of said first and second drive means for minimizing wear on said first and second drive means and preventing contact between said fluid shear drive means during relative operational wobble of said first and second drive means; plurality of protrusions formed on said wear-cushion memBer for being slidably mounted in said longitudinal slots to cause said wear-cushion member to rotate with said first drive member and to permit said wear-cushion member to slide axially relative to said first drive member and thereby permit said fluid medium to provide a fluid shear drive relationship between said wear-cushion member and said second drive member and to provide a cushioning means between said wear-cushion member and said first drive member.

Claim 9

A viscous fluid clutch comprising relatively rotatable housing and clutch plate members, said housing 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 to first and second chambers, said clutch plate member being rotatable in said first chamber, said clutch plate member and said rear wall having opposed spaced annular parallel ridge and groove surfaces formed thereon 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 in said first chamber adjacent said first opening for causing said fluid medium to flow through said first opening for varying the volume of said fluid medium in said shear space to vary the torque transmitted between said housing and clutch plate members, a second opening formed in said divider wall for at times communicating said fluid medium for 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 housing and clutch plate members, an annular wear-cushion member secured for rotation with an axial movement relative to said housing member and adjacent opposing faces of said clutch plate and housing members, said faces being located radially outwardly of said opposed spaced annular parallel ridge and groove surfaces.

Claim 10

A viscous fluid clutch comprising relatively rotatable housing and clutch plate members, said housing 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 to first and second chambers, said clutch plate member being rotatable in said first chamber, said clutch plate member and said rear wall having opposed spaced annular parallel ridge and groove surfaces formed thereon 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 in said first chamber adjacent said first opening for causing said fluid medium to flow through said first opening for varying the volume of said fluid medium in said shear space to vary the torque transmitted between said housing and clutch plate members, a second opening formed in said divider wall for at times communicating said fluid medium for 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 housing and clutch plate members, an annular wear-cushion member secured for rotation with an axial movement relative to said housing member and adjacent opposing faces of said clutch plate and housing members, said faces being located radially outwardly of said opposed spaced annular parallel ridge and groove surfaces.

Claim 11

The viscous fluid clutch described in claim 6, and bimetallic thermostat means for actuating said valve means.

Claim 12

The viscous fluid clutch described in claim 6, wherein said faces are parallel to one another and extend radially outwardly from the axis of said viscous fluid clutch.

Claim 13

The viscous fluid clutch described in claim 6, wherein said face on said clutch plate includes a first portion closely adjacent an outer annular portion of said wear-cushion member and an inwardly extending portion tapering away from said wear-cushion member, and said face on said housing includes a first portion closely adjacent an inner annular portion of said wear-cushion member of the side opposite said outer annular portion and an outwardly extending portion tapering away from said wear-cushion member, said wear-cushion member being caused to flex intermediate and housing and clutch plate members during relative pivotal movement of one of said housing and clutch plate members, thereby cushioning the impact therebetween.

Claim 14

The viscous fluid clutch described in claim 6, wherein said face on said clutch plate a first portion closely adjacent a first annular portion of said wear-cushion member and a second portion tapering away from said wear-cushion member and a second portion tapering away from said wear-cushion member, ans said face on said housing includes a first portion closely adjacent a second annular portion of said wear-cushion member on the side opposite said first annular portion and a second portion tapering away from said wear-cushion member, said wear-cushion member being caused to flex intermediate said housing and clutch plate members during relative pivotal movement of one of said housing and clutch plate members, thereby cushioning the impact therebetween.