This fluid-type retarding device includes: a rotating disk provided to a rotating shaft; a rotating housing that includes paired disk portions and a cylinder portion connecting outer circumferential portions of the disk portions so as to surround the rotating disk, and is rotatably supported with the rotating shaft; and a friction brake that presses a friction member against the rotating housing at the time of braking to bring the rotating housing to a stop. On at least one surface of the rotating disk, a disk vane extending from an inner circumference of the surface toward an outer peripheral side is formed, and on an inner surface of each of the paired disk portions corresponding to the disk vane, a housing vane extending from an inner circumference to an outer periphery is formed. Furthermore, working fluid is accommodated within the rotating housing.

A rotational speed control device includes a housing containing a viscous fluid, a shaft disposed in the housing and rotatable relative to the housing, a hub assembly secured to the shaft for rotation with the shaft, and a rotor coupled with the shaft by a frictional engagement with the hub assembly. A spring is disposed in the housing and acts on the rotor to bias the rotor axially on the shaft in a low torque direction. A braking torque between the rotor and the housing is varied according to an axial position of the rotor on the shaft.

A rotational speed control device includes a housing containing a viscous fluid, a shaft disposed in the housing and rotatable relative to the housing, a hub assembly secured to the shaft for rotation with the shaft, and a rotor coupled with the shaft by a frictional engagement with the hub assembly. A spring is disposed in the housing and acts on the rotor to bias the rotor axially on the shaft in a low torque direction. A braking torque between the rotor and the housing is varied according to an axial position of the rotor on the shaft.

A cooling circuit for a motor vehicle having a cooling medium pump that circulates a cooling medium in the cooling circuit having a hydrodynamic retarder. The cooling circuit further includes a main circuit in which the cooling medium pump and a drive motor of the motor vehicle, as well as a heat exchanger are positioned. A secondary branch of the cooling circuit includes a feed that branches off from the main circuit at a branch-off point and ends in the hydrodynamic retarder, and a return which proceeds from the hydrodynamic retarder and ends at a junction location in the main circuit. The return ends upstream of the branch-off location of the feed as viewed in a flow direction of the cooling medium in the main circuit, however on the same side of the cooling medium pump or at the branch-off location of the feed in the main circuit.

A cooling circuit for a motor vehicle having a cooling medium pump that circulates a cooling medium in the cooling circuit having a hydrodynamic retarder. The cooling circuit further includes a main circuit in which the cooling medium pump and a drive motor of the motor vehicle, as well as a heat exchanger are positioned. A secondary branch of the cooling circuit includes a feed that branches off from the main circuit at a branch-off point and ends in the hydrodynamic retarder, and a return which proceeds from the hydrodynamic retarder and ends at a junction location in the main circuit. The return ends upstream of the branch-off location of the feed as viewed in a flow direction of the cooling medium in the main circuit, however on the same side of the cooling medium pump or at the branch-off location of the feed in the main circuit.

A bearing raceway ring (25) disposed near a mounting section (9) is disposed on the outer periphery of a circular cylinder section (19). A fluid-sealed chamber (40) in which a measurement liquid is hermetically enclosed is provided between a first member (8) and the bearing raceway ring (25) which is disposed near the mounting section (9). Pressure acting on the fluid to be measured changes as the bearing raceway ring (25) moves in the cylinder-axis direction, the bearing raceway ring (25) being disposed near the mounting section (9). The fluid-sealed chamber (40) is provided with a pressure sensor (44) capable of detecting a change in the pressure of the fluid to be measured.

A method and a system to control an auxiliary brake system in a vehicle 100 having a service brake system 150 and an auxiliary brake system 160. Also a system for prevention of wheel lock when braking, which may deactivate a braking action provided by the auxiliary brake system 160 and may actively control a braking action provided by the service brake system 150. The system determines whether the vehicle 100 is in a driving mode for which it is acceptable in terms of safety and/or drivability to block the deactivation of the braking action for the auxiliary brake system 160. If a first manual control 170, which is set up solely for activating braking action for the auxiliary brake system 160, is activated, this means it is acceptable, from a safety and/or drivability point of view, for the driving mode in question, to block the deactivation. Also arranging block deactivation for the auxiliary brake system 160 if it is acceptable in terms of safety and drivability to block it.

A method and a system to control an auxiliary brake system in a vehicle 100 having a service brake system 150 and an auxiliary brake system 160. Also a system for prevention of wheel lock when braking, which may deactivate a braking action provided by the auxiliary brake system 160 and may actively control a braking action provided by the service brake system 150. The system determines whether the vehicle 100 is in a driving mode for which it is acceptable in terms of safety and/or drivability to block the deactivation of the braking action for the auxiliary brake system 160. If a first manual control 170, which is set up solely for activating braking action for the auxiliary brake system 160, is activated, this means it is acceptable, from a safety and/or drivability point of view, for the driving mode in question, to block the deactivation. Also arranging block deactivation for the auxiliary brake system 160 if it is acceptable in terms of safety and drivability to block it.

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. In one arrangement, 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. In another arrangement, the rotor may be designed to cooperate with the housing or other nonrotating features within the housing to vary a shear gap according to radially expanding components 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 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. In one arrangement, 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. In another arrangement, the rotor may be designed to cooperate with the housing or other nonrotating features within the housing to vary a shear gap according to radially expanding components 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.