A hydrodynamic retarder system for a vehicle is provided. In a first operational state with the vehicle powered on and a retarder deactivated, a pump directs fluid flow from a fluid sump to a retarder inlet valve in the closed position and directs fluid flow to a second sump. In a second operational state with the vehicle on and the retarder activated, the retarder inlet valve moves to the open position directing fluid flow into a retarder chamber and flowing out of the retarder chamber after filling a second volume and discharging to the second sump.

This travel control device includes: a road determining unit which determines whether a road including a downward slope along which a vehicle is traveling includes a first curved road and a second curved road; and a travel control unit which, if the road determining unit has determined that the road contains the first curved road and the second curved road, causes the vehicle, when being caused to travel in such a way as to maintain a target speed, to decelerate at a curved road entry side of the first curved road and to coast from a curved road exit side of the first curved road, such that the vehicle can pass through the first curved road.

A wet brake system, a method therefor, and a vehicle including such system, the system comprising: a housing enclosing a brake compartment, at least one friction plate rotatably disposed within the brake compartment, at least one separator plate disposed within the brake compartment, coupled to the housing and configured to be frictionally engaged with the at least one friction plate for braking the at least one friction plate, the at least one friction plate and the at least one separator plate configured to be at least partially submersed in a liquid held within the brake compartment, and a liquid reservoir, wherein a drain port is arranged such that the at least one friction plate when rotating is configured to convey liquid held within the brake compartment to the liquid reservoir via the drain port and a drain channel for draining the brake compartment.

A hydrodynamic retarder having a rotor and a stator or a rotor and an oppositely running rotor, which together form a toroidal working chamber to filled with working medium, in order to transmit a torque by means of a hydrodynamic working chamber working medium circuit. An external working medium circuit has a heat exchanger that discharges heat from the working medium. The external working medium circuit is connected by a working medium inlet and a working medium outlet to the working chamber. The working medium inlet and outlet open to the working chamber at a torus outer diameter of the working chamber. A working medium feed line opens into the external working medium circuit. A core ring filling line is connected in working-medium-conducting fashion to the working chamber. The core ring filling line opens into a core ring of the working chamber radially within the torus outer diameter.

A hydrodynamic retarder having a rotor and a stator or a rotor and an oppositely running rotor, which together form a toroidal working chamber to filled with working medium, in order to transmit a torque by means of a hydrodynamic working chamber working medium circuit. An external working medium circuit has a heat exchanger that discharges heat from the working medium. The external working medium circuit is connected by a working medium inlet and a working medium outlet to the working chamber. The working medium inlet and outlet open to the working chamber at a torus outer diameter of the working chamber. A working medium feed line opens into the external working medium circuit. A core ring filling line is connected in working-medium-conducting fashion to the working chamber. The core ring filling line opens into a core ring of the working chamber radially within the torus outer diameter.

A cooling system and method for an auxiliary braking device of a hydrogen fuel cell truck, are provided in consideration that auxiliary braking force generated by the regenerative braking of the motor may be unnecessary and the brake resistor may be unnecessary when a sufficient amount of auxiliary braking force is generated alone by the operation of a retarder. A portion of thermal energy generated by the retarder is distributed to a stack cooling system so that the portion of thermal energy is removed by the stack cooling system. Accordingly, due to sufficient cooling of the retarder, a sufficient amount of auxiliary braking force is provided, and the brake resistor that has consumed surplus electrical energy generated by regenerative braking is removed.

The present invention relates to an auxiliary transmission brake arrangement (100) for a transmission (10) of a vehicle. In particular, the invention relates to an auxiliary transmission brake arrangement comprising a lubrication arrangement for improved lubrication of gear wheels connecting the auxiliary transmission brake arrangement to an output shaft.

A brake system may comprise a hydraulic brake system or a hybrid brake system. The hydraulic brake system may include an inner axle disposed in an inner axle housing. The inner axle housing may include a working fluid therein. The inner axle may comprise a plurality of paddles extending radially from the inner axle. The working fluid may be pressurized and/or create friction with the plurality of paddles. The pressurized working fluid may impede a free rotation of the plurality of paddles.

A brake system may comprise a hydraulic brake system or a hybrid brake system. The hydraulic brake system may include an inner axle disposed in an inner axle housing. The inner axle housing may include a working fluid therein. The inner axle may comprise a plurality of paddles extending radially from the inner axle. The working fluid may be pressurized and/or create friction with the plurality of paddles. The pressurized working fluid may impede a free rotation of the plurality of paddles.

A drive train has a hydrodynamic retarder including a rotating bladed rotor and bladed stator, forming a working chamber for hydrodynamic transmission of power from rotor to stator, a power input feeding drive power to the retarder, and a synchronized separating clutch connected between power input and rotor. The clutch has two clutch halves, friction elements contacting each other and mechanical blocking elements. The friction elements equalize rotational speed between clutch halves, and the blocking elements form-lockingly connect the clutch halves. The clutch has an actuator displaceable along a displacement travel, over a first distance bringing the friction elements into mutual contact, and a second distance adjoining the first distance to synchronize the friction elements and rotational speed for locking with the blocking elements. At least one displacement sensor directly or indirectly detects displacement travel by the actuator and/or position of the actuator on the displacement travel.