A hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and an electrohydraulic system including an open loop unit and a and closed loop control unit, a working medium accumulator, a pump operable to pump a working medium from the working medium accumulator into the toroidal working chamber, a heat exchanger, a valve operable to switch between a first position, the first position being a non-braking position, and a second position, the second position being a braking position, and a line system operable to allow the pump to pump the working medium in both the first position and the second position into the working chamber.

The present disclosure is directed to a braking system for a work vehicle having hydraulically-actuated brakes. The braking system includes a primary release valve, a secondary release valve, and at least one braking mechanism having one or more brake springs. The braking mechanism(s) is hydraulically coupled to the primary release valve and the secondary release valve via one or more hydraulic lines. As such, during full-power operation of the work vehicle, when the brakes are to be released, the primary release valve is energized so as to overcome a valve biasing spring, thereby shifting the primary release valve so as to direct pressurized hydraulic fluid to the braking mechanism(s). Further, when the brakes are to be applied, the primary release valve is inactive so as to allow the hydraulic fluid to flow away from the braking mechanism(s) to a primary reservoir such that the one or more brake springs compress the braking mechanism(s). Alternatively, when power is lost to the work vehicle, the secondary release valve bypasses the primary release valve and directs pressurized hydraulic fluid to the braking mechanism(s) to release the brakes.

A hydraulic drive unit for use in a vehicle or other application incorporates a motor connected to a pump through a porting system and an output shaft driven by the motor. A mechanical brake is used to brake the motor, while a valve provides a hydraulic brake for preventing flow between the hydraulic motor and the hydraulic pump. A brake actuator is connected to both the mechanical brake and the hydraulic brake, whereby actuation of the brake actuator causes both the mechanical brake and the hydraulic brake to be actuated.

A power machine can include a frame, a power source, a machine hydraulic system, and a rotary implement removably securable to the frame. The machine hydraulic system can provide operational hydraulic power to a hydraulic motor of the rotary implement through an implement hydraulic circuit. In an implement braking mode, flow of hydraulic fluid through the implement hydraulic circuit can provide braking for the hydraulic motor.

A power machine can include a frame, a power source, a machine hydraulic system, and a rotary implement removably securable to the frame. The machine hydraulic system can provide operational hydraulic power to a hydraulic motor of the rotary implement through an implement hydraulic circuit. In an implement braking mode, flow of hydraulic fluid through the implement hydraulic circuit can provide braking for the hydraulic motor.

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.

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 electro-hydrostatic brake system includes a motor controller configured to receive a brake command, a motor in electronic control communication with the motor controller, and a pump mechanically coupled to the motor. In various embodiments, the electro-hydrostatic brake system further includes a hydraulic tank fluidly coupled in fluid providing communication with the pump, a hydraulic pressure rail fluidly coupled in fluid receiving communication with the pump, and a brake actuator in fluid communication with the hydraulic pressure rail and configured to exert a braking force on a wheel, wherein the braking force is directly modulated by the motor and/or the pump.

A hydraulic cylinder retarder includes a hydraulic cylinder mechanism, a hydraulic oil conveying mechanism and a hydraulic oil valve mechanism. A piston component of the hydraulic cylinder mechanism is connected to a transmission device. Resistance to the piston movement of the hydraulic cylinder mechanism is generated by the hydraulic oil conveying mechanism and the hydraulic oil valve mechanism, so as to reduce the operation speed of the transmission device.

A hydraulic cylinder retarder includes a hydraulic cylinder mechanism, a hydraulic oil conveying mechanism and a hydraulic oil valve mechanism. A piston component of the hydraulic cylinder mechanism is connected to a transmission device. Resistance to the piston movement of the hydraulic cylinder mechanism is generated by the hydraulic oil conveying mechanism and the hydraulic oil valve mechanism, so as to reduce the operation speed of the transmission device.