Viscous fluid clutch with cooling passage means

Claim 2

A viscous clutch comprising first and second relatively rotatable drive means, said first drive means containing a fluid medium and 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 operable with said fluid medium to provide a shear-type fluid drive between said first and second drive means, said operating chamber having an outlet opening at an outer portion and an inlet opening at an inner portion, said first drive means having cooling passage means having an inlet connected to said outlet opening, a heat transfer portion cooled directly by ambient air and an outlet portion connected to said reservoir in a zone radially inward of the annular level of said fluid medium when all of said fluid medium is contained in said reservoir, and pump means on one of said drive means to pump said fluid medium from said operating chamber out of said outlet opening and through said cooling passage means and said outlet portion thereof to said reservoir chamber.

Claim 3

A viscous 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 operable with a fluid to provide a shear-type fluid drive between said drive means, said operating chamber having an outlet opening at an outer portion and an inlet opening at an inner portion, said first drive means having cooling passage means having an inlet connected to said outlet opening, a heat-transfer portion cooled directly by ambient air and an outlet portion connected to said reservoir radially inward of said operating chamber, and pump means on one of said drive means to pump fluid from said operating chamber out of said outlet opening.

Claim 4

A viscous 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 operable with a fluid to provide a shear-type fluid drive between said drive means, said operating chamber having an outlet opening at an outer portion and an inlet opening at an inner portion, said first drive means having cooling passage means having an inlet connected to said outlet opening, a heat-transfer portion cooled directly by ambient air and an outlet portion connected to said reservoir radially inward of said operating chamber, and pump means on one of said drive means to pump fluid from said operating chamber out of said outlet opening.

Claim 5

A viscous 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 operable with a fluid to provide a shear-type fluid drive between said drive means, said operating chamber having an outlet opening at an outer portion and an inlet opening at an inner portion, said first drive means having cooling passage means having an inlet connected to said outlet opening, a heat-transfer portion cooled directly by ambient air for maintaining the fluid in the heat-transfer portion separate from the fluid in the reservoir and an outlet portion connected to said reservoir in a zone radially inward of and axially spaced from said inlet opening, and pump means on one of said drive means to pump fluid from said operating chamber out of said outlet opening.

Claim 6

A viscous 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 operable with a fluid to provide a shear-type fluid drive between said drive means, said operating chamber having an outlet opening at an outer portion and an inlet opening at an inner portion, said first drive means having cooling passage means having an inlet connected to said outlet opening, a heat-transfer portion cooled directly by ambient air for maintaining the fluid in the heat-transfer portion separate from the fluid in the reservoir and an outlet portion connected to said reservoir in a zone radially inward of and axially spaced from said inlet opening, and pump means on one of said drive means to pump fluid from said operating chamber out of said outlet opening.

Claim 7

A viscous fluid clutch comprising a first member, a second member including forward and rear walls encompassing said first member and being rotatably supported thereon, an operating chamber forming a viscous shear drive relation between said members, interior wall means cooperating with one of said members to form an annular reservoir therebetween, viscous fluid disposed in said operating chamber and adapted to be transferred to said annular reservoir, first and second ports operatively connected to said operating chamber, pump means operatively connected to said first member for pumping said viscous fluid from said operating chamber through said first port, saiD second port communicating with said annular reservoir, and cooling means including annular passage means having annular inner opening means adapted to receive said viscous fluid from said first port and to maintain said fluid in contact with one of said walls of said second member apart from said annular reservoir until delivery to the radially inner portion of said annular reservoir via said annular inner opening means.

Claim 8

A viscous fluid clutch comprising a first member, a second member including forward and rear walls encompassing said first member and being rotatably supported thereon, an operating chamber forming a viscous shear drive relation between said members, interior wall means cooperating with one of said members to form an annular reservoir therebetween, viscous fluid disposed in said operating chamber and adapted to be transferred to said annular reservoir, first and second ports operatively connected to said operating chamber, pump means operatively connected to said first member for pumping said viscous fluid from said operating chamber through said first port, saiD second port communicating with said annular reservoir, and cooling means including annular passage means having annular inner opening means adapted to receive said viscous fluid from said first port and to maintain said fluid in contact with one of said walls of said second member apart from said annular reservoir until delivery to the radially inner portion of said annular reservoir via said annular inner opening means.

Claim 9

The viscous fluid clutch described in claim 4, and valve means for controlling the flow of said viscous fluid through said second port.

Claim 10

The viscous fluid clutch described in claim 5, and temperature control means for operating said valve 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 an operating 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 operating chamber operable with a fluid medium to provide a shear-type fluid drive therebetween, baffle wall means between said first wall and said divider wall in said second chamber dividing said second chamber into an annular reservoir adjacent the divider wall and an annular cooling passage adjacent the front wall and having an inlet and an outlet delivering fluid to said reservoir for maintaining fluid in contact with the inner surface of said front wall and separate from fluid in said reservoir, a first opening means in said first member for providing communication from said operating chamber to said annular cooling passage inlet, pump means on one of said drive members for causing said fluid medium to flow from said operating chamber through said first opening means to said cooling passage inlet and second opening means formed in said divider wall for communicating said fluid medium from said reservoir to said operating chamber.

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 an operating 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 operating chamber operable with a fluid medium to provide a shear-type fluid drive therebetween, baffle wall means between said first wall and said divider wall in said second chamber dividing said second chamber into an annular reservoir adjacent the divider wall and an annular cooling passage adjacent the front wall and having an inlet and an outlet delivering fluid to said reservoir for maintaining fluid in contact with the inner surface of said front wall and separate from fluid in said reservoir, a first opening means in said first member for providing communication from said operating chamber to said annular cooling passage inlet, pump means on one of said drive members for causing said fluid medium to flow from said operating chamber through said first opening means to said cooling passage inlet and second opening means formed in said divider wall for communicating said fluid medium from said reservoir to said operating chamber.

Claim 13

A viscous fluid clutch comprising an input shaft, a clutch plate secured to said shaft, a fluid clutch housing rotatably mounted on said input shaft, a cover member sealed to said housing, a divider wall secured for rotation with said cover member and said housing and mounted between said cover member and said clutch plate so as to form an annular chamber with said cover member and an operating chamber with said housing, baffle wall means secured for rotation with said cover member and said housing in said annular chamber and forming a narrow annular passage with said cover member and an annular reservoir with said divider wall, a first opening formed in said divider wall between said operating chamber and said narrow annular passage, pump means operatively connected to said divider wall for pumping a fluid medium from said operating chamber through said first opening to said annular passage, a second opening formed in said divider wall for at times communicating said fluid medium from said annular reservoir to said operating chamber, and temperature-responsive valve means operatively connected to said divider wall for controlling the flow of said fluid medium through said second opening, said narrow annular passage spacing said annular reservoir from said cover member and providing means for cooling said fluid medium prior to entry into said annular reservoir at a point radially inward of the inner annular surface level of said fluid medium as determined by the action of centrifugal force thereon.

Claim 14

A viscous fluid clutch comprising an input shaft, a clutch plate secured to said shaft, a fluid clutch housing rotatably mounted on said input shaft, a cover member sealed to said housing, a divider wall secured for rotation with said cover member and said housing and mounted between said cover member and said clutch plate so as to form an annular chamber with said cover member and an operating chamber with said housing, baffle wall means secured for rotation with said cover member and said housing in said annular chamber and forming a narrow annular passage with said cover member and an annular reservoir with said divider wall, a first opening formed in said divider wall between said operating chamber and said narrow annular passage, pump means operatively connected to said divider wall for pumping a fluid medium from said operating chamber through said first opening to said annular passage, a second opening formed in said divider wall for at times communicating said fluid medium from said annular reservoir to said operating chamber, and temperature-responsive valve means operatively connected to said divider wall for controlling the flow of said fluid medium through said second opening, said narrow annular passage spacing said annular reservoir from said cover member and providing means for cooling said fluid medium prior to entry into said annular reservoir at a point radially inward of the inner annular surface level of said fluid medium as determined by the action of centrifugal force thereon.

Claim 15

A viscous fluid clutch comprising an input shaft, a first member secured to said shaft, a second member rotatably mounted on said input shaft, a cover member fixed to said second member such that said first member is relatively rotatable between said second member and said cover member, a divider wall secured for rotation with said cover member and said second member and mounted between said cover member and said first member so as to form an annular chamber with said cover member and an operating chamber with said second member, baffle wall means operatively connected to said cover member for rotation therewith in said annular chamber and forming a narrow annular passage with said cover and an annular reservoir with said divider wall, an annular opening formed at the radial innermost portion of said narrow annular passage adjacent said annular reservoir, a second opening formed in said divider wall between said operating chamber and said narrow annular passage, pump means operatively connected to said first and second members for forcing a fluid medium from said operating chamber through said second opening to said narrow annular passage bypassing said annular reservoir, said narrow annular passage serving to expose said fluid medium to a maximum area of said cover member prior to the exit of said fluid medium through said annular opening into said annular reservoir, thereby cooling said fluid medium, a third opening formed in said divider wall for permitting said fluid medium to flow from said annular reservoir to said operating chamber.

Claim 16

A viscous fluid clutch comprising an input shaft, a first member secured to said shaft, a second member rotatably mounted on said input shaft, a cover member fixed to said second member such that said first member is relatively rotatable between said second member and said cover member, a divider wall secured for rotation with said cover member and said second member and mounted between said cover member and said first member so as to form an annular chamber with said cover member and an operating chamber with said second member, baffle wall means operatively connected to said cover member for rotation therewith in said annular chamber and forming a narrow annular passage with said cover and an annular reservoir with said divider wall, an annular opening formed at the radial innermost portion of said narrow annular passage adjacent said annular reservoir, a second opening formed in said divider wall between said operating chamber and said narrow annular passage, pump means operatively connected to said first and second members for forcing a fluid medium from said operating chamber through said second opening to said narrow annular passage bypassing said annular reservoir, said narrow annular passage serving to expose said fluid medium to a maximum area of said cover member prior to the exit of said fluid medium through said annular opening into said annular reservoir, thereby cooling said fluid medium, a third opening formed in said divider wall for permitting said fluid medium to flow from said annular reservoir to said operating chamber.

Claim 17

The viscous fluid clutch described in claim 9, and valve means operatively connected to said third opening for controlling passage of said fluid medium therethrough.

Claim 18

The viscous fluid clutch described in claim 10, and bimetallic thermostat means for actuating said valve means.

Claim 19

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, baffle wall means operatively connected to said divider wall in said second chamber and dividing said second chamber into an annular reservoir and an annular cooling passage and forming an annular inner opening with said front wall, a first opening formed in said divider wall for providing communication between said first chamber and said annular cooling passage, 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 reservoir to said first chamber, a temperature-responsive valve 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, said annular cooling passage maintaining said fluid medium being pumped from said first chamber in contact with the inner surface of said front wall and delivering said fluid medium via said annular inner opening to the radial inner portion of said annular reservoir remote from said valve-controlled second opening.

Claim 20

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, baffle wall means operatively connected to said divider wall in said second chamber and dividing said second chamber into an annular reservoir and an annular cooling passage and forming an annular inner opening with said front wall, a first opening formed in said divider wall for providing communication between said first chamber and said annular cooling passage, 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 reservoir to said first chamber, a temperature-responsive valve 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, said annular cooling passage maintaining said fluid medium being pumped from said first chamber in contact with the inner surface of said front wall and delivering said fluid medium via said annular inner opening to the radial inner portion of said annular reservoir remote from said valve-controlled second opening.