A damping apparatus for a drivetrain of a motor vehicle, with a first damping element which is rotatable about an axis of rotation, a second damping element which can be driven by the first damping element and is thereby rotatable about the axis of rotation, at least two damping chambers, the volumes of which can be modified by a relative rotation between the damping elements, at least one overflow channel, by which the damping chambers are connected to one another fluidly, and having a damping fluid, which flows from one damping chamber into the other damping chamber via the overflow channel upon a volume reduction of one of the damping chambers. The overflow channel flowing into the respective damping chambers at both ends is formed by a gap between the damping elements, the gap being directly limited by the damping elements, at least in a lengthwise region.

A viscous damper has an inertial mass in the form of a tubular member that is applicable for dissipating (removing) destructive torsional vibration in power transmitting shaft assemblies. A viscous fluid contained between moving surfaces is sheared, thereby producing frictional heat which is then allowed to transfer across the moving surfaces to the ambient surroundings. Surfaces of the inertial mass and housing are arranged with respect to each other to provide high shear rate and energy dissipation (damping) is obtained within a small volume.

A viscous damper has an inertial mass in the form of a tubular member that is applicable for dissipating (removing) destructive torsional vibration in power transmitting shaft assemblies. A viscous fluid contained between moving surfaces is sheared, thereby producing frictional heat which is then allowed to transfer across the moving surfaces to the ambient surroundings. Surfaces of the inertial mass and housing are arranged with respect to each other to provide high shear rate and energy dissipation (damping) is obtained within a small volume.

This invention discloses a novel product of a Wheel Hub Assembly for damping and noise reduction. It absorbs vibration and noise of brake rotor and brake drum in the braking process by changing flange face structure as well as adding damping coating. During the production, the flange face of the Wheel Hub Assembly is equipped with one or several technical groove(s) while a damping coating is designed to reduce vibration and noise. The damping coating is made of rubber materials, composite materials, damping coating materials or high polymer materials. In this invention, the damping coating is added between wheel hub and brake disk or brake drum. This can not only absorb a part of noise, but also reduce braking vibration to decrease the noise.

A power transmission device for a vehicle is disclosed. The power transmission device includes a first rotating member, a second rotating member configured to rotate relative to the first rotating member, a torque transmission portion, and a hydraulic pressure applying portion. The torque transmission portion is configured to transmit torque from one of the first rotating member and the second rotating member to the other of the first rotating member and the second rotating member by pressure of hydraulic fluid. The torque transmission portion is disposed between the first rotating member and the second rotating member. The hydraulic pressure applying portion is configured to apply pressure to the hydraulic fluid of the torque transmission portion.

A power transmission device for a vehicle is disclosed. The power transmission device includes a first rotating member, a second rotating member configured to rotate relative to the first rotating member, a torque transmission portion, and a hydraulic pressure applying portion. The torque transmission portion is configured to transmit torque from one of the first rotating member and the second rotating member to the other of the first rotating member and the second rotating member by pressure of hydraulic fluid. The torque transmission portion is disposed between the first rotating member and the second rotating member. The hydraulic pressure applying portion is configured to apply pressure to the hydraulic fluid of the torque transmission portion.

A rotary vibration reduction device for a motor vehicle for transmitting drive power from a drive machine to a drivetrain is provided. The vibration reduction device includes a primary and secondary connectors between the drive machine and drivetrain, and a coupling device between the primary connector and the secondary connector. The coupling device has a vibration reduction actuator with a piston chamber and has a piston element movable to generate a vibration reduction force in response to changes in working pressure in the piston chamber controlled by a pressure-generating device.

A rotary vibration reduction device for a motor vehicle for transmitting drive power from a drive machine to a drivetrain is provided. The vibration reduction device includes a primary and secondary connectors between the drive machine and drivetrain, and a coupling device between the primary connector and the secondary connector. The coupling device has a vibration reduction actuator with a piston chamber and has a piston element movable to generate a vibration reduction force in response to changes in working pressure in the piston chamber controlled by a pressure-generating device.

A viscous damper has an inertial mass in the form of a tubular member that is applicable for dissipating (removing) destructive torsional vibration in power transmitting shaft assemblies. A viscous fluid contained between moving surfaces is sheared, thereby producing frictional heat which is then allowed to transfer across the moving surfaces to the ambient surroundings. Surfaces of the inertial mass and housing are arranged with respect to each other to provide high shear rate and energy dissipation (damping) is obtained within a small volume.

A viscous damper has an inertial mass in the form of a tubular member that is applicable for dissipating (removing) destructive torsional vibration in power transmitting shaft assemblies. A viscous fluid contained between moving surfaces is sheared, thereby producing frictional heat which is then allowed to transfer across the moving surfaces to the ambient surroundings. Surfaces of the inertial mass and housing are arranged with respect to each other to provide high shear rate and energy dissipation (damping) is obtained within a small volume.