A friction device for a torsional vibration damper includes an axis of rotation, an input side with a first disc and a second disc, and an output side between the first disc and the second disc and rotatable relative to the input side. The output side has a first friction disc, a second friction disc, and a spring element between the first friction disc and the second friction disc. The spring element has first, second and third contact regions. At a first angle of rotation between the input side and the output side, an axial contact force between the first friction disc and the second friction disc is transmittable via the first contact region and the third contact region. At a second angle of rotation, different than the first angle of rotation, the axial contact force is transmittable via the second contact region and the third contact region.

Vehicles that are relatively heavy and/or configured to transport heavy loads may utilize a powertrain comprising an electric machine capable of operating at high speeds and a multispeed transmission to propel the vehicle. An interface module is configured to modulate torque between the electric machine and the multispeed transmission allowing the electric machine to smoothly match speed as the multispeed transmission shifts between gears. The interface module facilitates efficient, predictable, and reliable modulation of torque between an input and an output of the powertrain of the vehicle.

A torsion shaft assembly includes a torque carrying shaft including a driven end configured for receiving torque input to the torque carrying shaft and a driving end configured for outputting torque output from the toque carrying shaft. The torque carrying shaft includes an axial facing damping interface surface axially between the driven end and the driving end. A friction tube is disposed outboard of the torque carrying shaft. The friction tube is connected at a first axial location to be driven by the torque carrying shaft. The friction tube includes an axial facing damping interface surface that abuts the axial facing damping interface surface of the torque carrying shaft, forming a damping interface to provide frictional dampening against angular vibrations occurring as differential angular displacement between the driven end and the driving end of the torque carrying shaft.

A torsion shaft assembly includes a torque carrying shaft including a driven end configured for receiving torque input to the torque carrying shaft and a driving end configured for outputting torque output from the toque carrying shaft. The torque carrying shaft includes an axial facing damping interface surface axially between the driven end and the driving end. A friction tube is disposed outboard of the torque carrying shaft. The friction tube is connected at a first axial location to be driven by the torque carrying shaft. The friction tube includes an axial facing damping interface surface that abuts the axial facing damping interface surface of the torque carrying shaft, forming a damping interface to provide frictional dampening against angular vibrations occurring as differential angular displacement between the driven end and the driving end of the torque carrying shaft.

A torsion damping device for a vehicle drivetrain includes: a first rotary element, a second rotary element, an elastic device, a friction device including an actuating washer mounted to rotate as one with a friction washer and including an actuating tab interposed circumferentially between a first end of a spring and the first rotary element so as to allow relative rotation between the actuating washer and the second rotary element when the first end of the spring is compressed by the first rotary element in the direction of a second end of the spring opposite to the first end.

Systems and methods for damping torsional oscillations of downhole systems are described. The systems include a downhole drilling system disposed at an end of the downhole system in operative connection with a drill bit. A damping system is installed on the downhole drilling system, the damping system having at least one damper element configured to dampen at least one HFTO mode. At least one mode-shape tuning element is arranged on the drilling system. The at least one mode-shape tuning element is configured and positioned on the drilling system to modify at least one of a shape of the HFTO mode, a frequency of the HFTO mode, an excitability of the HFTO mode, and a damping efficiency of the at least one damper element.

Systems and methods for damping torsional oscillations of downhole systems are described. The systems include a downhole drilling system disposed at an end of the downhole system in operative connection with a drill bit. A damping system is installed on the downhole drilling system, the damping system having at least one damper element configured to dampen at least one HFTO mode. At least one mode-shape tuning element is arranged on the drilling system. The at least one mode-shape tuning element is configured and positioned on the drilling system to modify at least one of a shape of the HFTO mode, a frequency of the HFTO mode, an excitability of the HFTO mode, and a damping efficiency of the at least one damper element.

An apparatus for damping vibrations includes an inertial mass disposed in a cavity in a rotatable downhole component, the rotatable component configured to be disposed in a borehole in a subsurface formation, such as a resource bearing formation, the inertial mass coupled to a surface of the cavity by a damping fluid and configured to move within the cavity relative to the downhole component. The apparatus also includes a damping fluid disposed in the cavity between the inertial mass and an inner surface of the cavity, where rotational acceleration of the rotatable downhole component causes shear in the damping fluid to dissipate energy from rotational acceleration of the rotatable downhole component and causing the rotational acceleration to be reduced.

An apparatus for damping vibrations includes an inertial mass disposed in a cavity in a rotatable downhole component, the rotatable component configured to be disposed in a borehole in a subsurface formation, such as a resource bearing formation, the inertial mass coupled to a surface of the cavity by a damping fluid and configured to move within the cavity relative to the downhole component. The apparatus also includes a damping fluid disposed in the cavity between the inertial mass and an inner surface of the cavity, where rotational acceleration of the rotatable downhole component causes shear in the damping fluid to dissipate energy from rotational acceleration of the rotatable downhole component and causing the rotational acceleration to be reduced.

A power transmission device includes an input rotary member, an intermediate rotary member, an output rotary member, a friction engaging part and a load adjusting mechanism. A torque is inputted to the input rotary member. The torque is inputted from the input rotary member to the intermediate rotary member. The torque is outputted from the output rotary member. The friction engaging part is engaged by friction with a friction force depending on a load applied thereto. The friction engaging part is configured to transmit the torque between the intermediate rotary member and the output rotary member. The load adjusting mechanism is configured to adjust the load applied to the friction engaging part in accordance with the torque inputted to the input rotary member.