초록 ▼

A drive unit for vehicles with an engine and a gearbox, and with a hydrodynamic retarder. The retarder is in constant drive connection with the engine. The unit includes a coolant circuit whose coolant is at the same time the working medium of the retarder, and the retarder can be utilized as a cool

A drive unit for vehicles with an engine and a gearbox, and with a hydrodynamic retarder. The retarder is in constant drive connection with the engine. The unit includes a coolant circuit whose coolant is at the same time the working medium of the retarder, and the retarder can be utilized as a coolant pump. The retarder is arranged before the gearbox, and the retarder can be united with an engine brake to an overall brake unit (OBU). The overall brake unit is configured such that the retarder can in a braking operation engage sooner than the engine brake.

대표청구항 ▼

A method for operating a drive unit for a vehicle having an engine braking system, the drive unit comprising an engine, a gearbox, a retarder in constant drive connection with the engine, and a cooling circuit having a coolant comprising a working medium of the retarder, the retarder being usable as

A method for operating a drive unit for a vehicle having an engine braking system, the drive unit comprising an engine, a gearbox, a retarder in constant drive connection with the engine, and a cooling circuit having a coolant comprising a working medium of the retarder, the retarder being usable as a pump for the cooling circuit, wherein a maximum possible braking output is deliverable during sustained braking operation, said maximum possible braking output provided jointly by the retarder and the engine braking system, the method comprising: delivering an overall braking output during a sustained braking operation, said overall braking output comprising a first share and a second share, said first share being provided by the retarder and said second share being provided by the engine braking system; comparing the overall braking output delivered during the sustained braking operation to a maximum possible braking output of the engine braking system; and when said overall braking output is less than the maximum braking output of the engine braking system, activating the retarder to deliver the overall braking output; when the overall braking output is greater than the maximum braking output of the engine braking system, activating the engine braking system to deliver the maximum braking output of the engine braking system, and activating the retarder to deliver the difference between the overall braking output and the maximum braking output of the engine braking system.