A rotational speed control device includes a housing containing a viscous fluid and a shaft disposed in the housing and rotatable relative to the housing. A rotor may be movable axially on the shaft depending on the rotating speed of the shaft. The rotor is biased in a low torque direction. A braking torque between the rotor and the housing and/or between the rotor and a drive control ring is varied according to an axial position of the rotor on the shaft. The device may incorporate bypass channels to control a circulating pressure of the viscous fluid.

A rotational speed control device includes a housing containing a viscous fluid and a shaft disposed in the housing and rotatable relative to the housing. A rotor may be movable axially on the shaft depending on the rotating speed of the shaft. The rotor is biased in a low torque direction. A braking torque between the rotor and the housing and/or between the rotor and a drive control ring is varied according to an axial position of the rotor on the shaft. The device may incorporate bypass channels to control a circulating pressure of the viscous fluid.

Electronic devices, such as consumer electronics devices and constrol systems in vehicles are controlled by way of a haptic operating device with a rotating unit. Selectable menu items are displayed on a display unit, and a menu item is selected by rotating the rotating unit. The rotating unit latches at a number of haptically perceptible latching points during rotation. The number and rotational position of the haptically perceptible latching points is dynamically changed in accordance with a specific menu item selected by the user.

A braking control apparatus comprises at least one torque source. At least one magnetorheological (MR) fluid clutch apparatus having an input coupled to the at least one torque source to receive torque from the torque source, the MR fluid clutch apparatus controllable to transmit a variable amount of torque via an output thereof. A modulation interface couples the output of the at least one MR fluid clutch apparatus to a braking power transmission of a brake system. At least one sensor provides information indicative of a braking state of the load. A processing unit receives the information indicative of the braking state of the load and for outputting a signal to control the at least one MR fluid clutch apparatus in exerting a desired force on the braking power transmission to assist in braking the load. A method for assisting a manually-actuated braking of a vehicle is also provided.

A method for damping a movement of a door system of a vehicle that is equipped with a damping system having an adjustable and controllable damping action. A movement of the door system between a closed position and an open position is damped in a controlled manner. A measurement of the change in speed of the speed of movement of the door system is calculated and if the change in speed exceeds a predefined limit value, a set, gentle damping action is changed over to a greater damping action.

A door component has a controllable damper device that contains a magnetorheological fluid as a working fluid. Two connection units of the damper device can be moved relative to each other. One of the two connection units can be connected to a support structure, and the other connection unit can be connected to a pivotal door device in order to damp a movement of the door device between a closed position and an open position in a controlled manner. The magnetorheological damper device has a piston unit and a cylinder unit which surrounds the piston unit. The piston unit divides a cylinder volume into two chambers. The piston unit has a first piston rod, which extends through the first chamber, and a second piston rod, which extends through the second chamber.

An apparatus for retarding rotation of a nozzle includes a hollow housing, a rotary shaft within the housing, a rotatable rotor on the rotary shaft free to move axially along the shaft, and a cam assembly coupling the rotor and shaft together in the housing such that rotor rotation on the shaft causes the cam assembly to displace the rotor axially on the shaft in a first direction. A set of springs on the shaft biases the rotor in a second direction opposite the first direction on the shaft. Finally, a viscous fluid disposed between the rotor and the housing generates a drag on rotor rotation with the shaft. Relative rotation of the rotor with respect to the shaft in conjunction with a variable gap between the rotor and housing are used to slow and thus control rotary nozzle speed.

Apparatus and method for operating vehicles by way of a haptic operating device having a rotating unit. Selectable menu items are displayed on a display unit, and a menu item being selected by rotating the rotating unit. The rotating unit latches at a number of haptically perceptible latching points during rotation. The number and rotational position of the haptically perceptible latching points is dynamically changed.

A rotational speed control device maintains a shaft rotation speed. The device includes a housing containing a viscous fluid and a shaft disposed in the housing and rotatable relative to the housing. A rotor is coupled with the shaft for rotation in the viscous fluid. The rotor is axially displaceable along the shaft between a low-shear position and a high-shear position. A spring mechanism is disposed in the housing and biases the rotor toward the low-shear position. The rotor may be designed to cooperate with the housing or other nonrotating features within the housing to vary a shear gap according to the axial position of the rotor. The rotor, housing and spring mechanism can be designed to cooperate to create large changes in braking torque in response to small changes in shaft rotational speed. This allows the rotation speed to be controlled within a relatively narrow range.

A machine includes: an axle having wheels mounted to it; a brake system configured to provide service braking to the wheels; a brake pedal operatively connected to the brake system to provide a braking power to the wheels in proportion to the position of the brake pedal; a pedal sensor operatively connected to the brake pedal to sense the position of the brake pedal; a retarder system configured to selectively slow the wheels down; a speed sensor operatively connected to the machine to detect a speed associated with the machine; a controller operatively connected to the speed sensor, brake pedal position sensor, and retarder system wherein the controller is configured to operate the retarder system based on signals received from the speed sensor and brake pedal position sensor. A method for providing an indication to an operator may also be included.