Rotary viscous damper

A rotary viscous damper providing damping force constancy over an operating temperature range of a viscous working fluid, comprising:

• a damper housing defining an internal damping chamber for the viscous working fluid, said damper housing having an internal sidewall having a conical configuration with respect to the rotational axis of said rotary viscous damper, said conical internal sidewall defining a stationary conical damping surface of said rotary viscous damper;
• a shaft member mounted in rotatable combination with said damper housing;
• a rotor member mounted in combination with said shaft member, said rotor member being axially displaceable with respect to said shaft member, said rotor member having a peripheral surface having a conical configuration with respect to the rotational axis of said rotary viscous damper, said conical peripheral surface defining a rotating conical damping surface of said rotary viscous damper;
• said stationary conical damping surface and said rotating conical damping surface in opposed combination defining a shear gap of said rotary viscous damper;
• a bias spring having a constant spring force mounted in combination with said shaft member to exert said constant spring force against said rotor member;
• and
• a temperature compensation mechanism mounted in combination with said shaft member in compressive abutting engagement with said rotor member;
• said temperature compensation mechanism and said bias spring acting in combination against said rotor member to define a baseline shear gap for said rotary viscous damper;
• said temperature compensation mechanism being operative in response to temperature changes in the viscous working fluid to exert a temperature-dependent biasing force acting in opposition to said constant spring force against said rotor member to cause axial displacement thereof;
• axial displacement of said rotor member causing corresponding dimensional changes in said shear gap to compensate for changes in the viscosity of the viscous working fluid due to the temperature changes therein such that said rotary viscous damper provides damping force constancy over the operating temperature range of the viscous working fluid.

A rotary viscous damper, comprising:

• a damper housing defining an internal damping chamber for a viscous working fluid, said damper housing having an internal sidewall having a conical configuration with respect to the rotational axis of said rotary viscous damper, said damper housing further including a least one cylindrical partition wall protruding into said internal damping chamber, one sidewall of said at least one cylindrical partition wall having a conical configuration with respect to the rotational axis of said rotary viscous damper, said conical internal wall and said at least one conical partition sidewall defining stationary conical damping surfaces of said rotary viscous damper;
• a shaft member rotatably mounted in combination with said damper housing;
• at least first and second rotor members mounted in combination with said shaft member and in abutting engagement with one another, each of said first and second rotor members having a peripheral surface having a conical configuration with the rotation axis of said rotary viscous damper, said conical peripheral surfaces defining rotating conical damping surfaces of said rotary viscous damper;
• said stationary conical damping surfaces and said rotating conical damping surfaces in opposed combination defining first and second baseline shear gaps of said rotary viscous damper;
• and
• adjustment means for axially positioning said at least first and second rotor members to vary said first and second baseline shear gaps of said rotary viscous damper.