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 vehicle may include rear ground traction members, front ground traction members, a rear drive system to drive the rear ground traction members, a continuously variable speed front drive system to drive the front ground traction members and a controller. The variable speed front drive system may include a hydraulic pump, a hydraulic motor driven by the hydraulic pump and operably coupled to the front ground traction members by a planetary gear assembly. The planetary gear assembly may include a sun gear coupled to and driven by the hydraulic motor, a ring gear operably coupled to the rear ground traction members and a planet carrier carrying planet gears intermeshing between the ring gear and the sun gear. The planet carrier has an output shaft operably coupled to the front ground traction members. At least one sun brake is actuatable by the controller to retard rotation of the sun gear.

A vehicle may include rear ground traction members, front ground traction members, a rear drive system to drive the rear ground traction members, a continuously variable speed front drive system to drive the front ground traction members and a controller. The variable speed front drive system may include a hydraulic pump, a hydraulic motor driven by the hydraulic pump and operably coupled to the front ground traction members by a planetary gear assembly. The planetary gear assembly may include a sun gear coupled to and driven by the hydraulic motor, a ring gear operably coupled to the rear ground traction members and a planet carrier carrying planet gears intermeshing between the ring gear and the sun gear. The planet carrier has an output shaft operably coupled to the front ground traction members. At least one sun brake is actuatable by the controller to retard rotation of the sun gear.

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 drive device for a vehicle having a combustion engine and a multistage manual transmission having first and second sub-transmissions, each of which has a separate input shaft. A first input shaft of the first sub-transmission couples, via a first clutch, the combustion engine or is assigned an electrical machine. A second input shaft of a second sub-transmission couples, via a second clutch, the combustion engine. The first input shaft is additionally assigned a start-up element having at least one hydrodynamic transfer element, which has first and second functional wheels which together form a working chamber. The working chamber can be filled with fluid in order to generate a hydrodynamic transfer torque such that at least one start-up function, affecting the first sub-transmission, can carried out by way of the start-up element.

A drive device for a vehicle having a combustion engine and a multistage manual transmission having first and second sub-transmissions, each of which has a separate input shaft. A first input shaft of the first sub-transmission couples, via a first clutch, the combustion engine or is assigned an electrical machine. A second input shaft of a second sub-transmission couples, via a second clutch, the combustion engine. The first input shaft is additionally assigned a start-up element having at least one hydrodynamic transfer element, which has first and second functional wheels which together form a working chamber. The working chamber can be filled with fluid in order to generate a hydrodynamic transfer torque such that at least one start-up function, affecting the first sub-transmission, can carried out by way of the start-up element.

Technologies for variable retarder control include a control valve for controlling operation of a hydraulic retarder. The control valve includes a valve body having a retarder valve including multiple ports and a valve bore extending through the ports. A valve spool is located in the valve bore and movable to selectively block or connect one or more of the ports. The ports include a retarder-out port and an exhaust port, which are fluidly coupled to each other via an exhaust passageway. In use, the exhaust passageway bleeds lubrication fluid from the retarder-out port to the exhaust port as the valve spool is moved from a fully-off position to a fully-on position. The exhaust passageway is shaped so as to provide a linear relationship between the positioning of the valve spool between the fully-off and fully-on positions and the power of the hydraulic retarder. The control valve may also include a lubrication regulator valve configured to supply lubrication oil to the system while the hydraulic retarder is being bled to the exhaust port via the exhaust passageway to maintain appropriate lubrication pressures in the system.

The present disclosure relates to a device for energy recovery for an electrically driven motor vehicle. The device includes an electric drive unit for driving the motor vehicle and a permanent brake deice which is designed as a hydrodynamic retarder and is or can be drivingly connected to the electric drive unit. A waste heat recovery device has an expansion machine which is or can be connected to the permanent brake device for energy recovery of a waste heat resulting from the braking of the permanent brake device. The present disclosure also relates to a method for energy recovery in an electrically driven motor vehicle.

The present disclosure relates to a device for energy recovery for an electrically driven motor vehicle. The device includes an electric drive unit for driving the motor vehicle and a permanent brake deice which is designed as a hydrodynamic retarder and is or can be drivingly connected to the electric drive unit. A waste heat recovery device has an expansion machine which is or can be connected to the permanent brake device for energy recovery of a waste heat resulting from the braking of the permanent brake device. The present disclosure also relates to a method for energy recovery in an electrically driven motor vehicle.