The invention relates to a drive device for a vehicle, comprising at least one electric machine, in particular an electric motor, having a rotor and a stator, a drive axle and a main service brake, the drive device being equipped with an additional service brake in the form of a fluid gap brake, comprising a fluid gap which is situated between the rotor and the stator and can be flooded with a fluid to achieve a braking effect. The invention also relates to a vehicle having a drive device having a fluid gap brake and to a method for braking a drive device by means of the fluid gap brake, characterized by the following method steps: —flooding the fluid gap with fluid from a reservoir by means of the flooding device; —emptying the fluid gap of fluid into a reservoir by means of the drainage device.

A controllable hydrodynamic retarder system for a transmission including an electronic controller unit (ECU) for selecting and controlling brake torque by adjusting a retarder outlet pressure is described. The system can include an algorithm to calculate a retarder outlet pressure set point or tables or brake torque curves or profiles to allow the ECU to calculate or look up the functional relationships between the retarder RT outlet pressure, a vehicle or rotor speed, and a brake torque curve selected by the operator to provide the selected RT outlet pressure. The systems disclosed can also include a cooling system or utilize a vehicles engine cooling system. In one embodiment, the cooler can be shared between a transmission and the controllable retarder and can be adjusted to accommodate cooling requirements. The ECU can also make adjustments to the RT outlet pressure to address short term and long term RT overheating protection independent of the cooling system.

A controllable hydrodynamic retarder system for a transmission including an electronic controller unit (ECU) for selecting and controlling brake torque by adjusting a retarder outlet pressure is described. The system can include an algorithm to calculate a retarder outlet pressure set point or tables or brake torque curves or profiles to allow the ECU to calculate or look up the functional relationships between the retarder RT outlet pressure, a vehicle or rotor speed, and a brake torque curve selected by the operator to provide the selected RT outlet pressure. The systems disclosed can also include a cooling system or utilize a vehicles engine cooling system. In one embodiment, the cooler can be shared between a transmission and the controllable retarder and can be adjusted to accommodate cooling requirements. The ECU can also make adjustments to the RT outlet pressure to address short term and long term RT overheating protection independent of the cooling system.

A coolant diverter system and method of controlling coolant flow are provided. The coolant diverter system includes a coolant diverter body having a coolant inlet opening, a driveline retarder outlet opening and a bypass outlet opening. The coolant diverter system also includes a valve positioned in the coolant diverter body. The valve is configured in a first valve orientation to fluidly couple the coolant inlet opening to the driveline retarder outlet opening in isolation from the bypass outlet opening. The valve is configured in a second valve orientation to fluidly couple the coolant inlet opening to the driveline retarder outlet opening and the bypass outlet opening. The coolant diverter system also includes a valve controller configured to place the valve in the first valve orientation in response to activation of a driveline retarder coupled to the driveline retarder outlet opening for braking.

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.

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.

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.

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.