Abstract: The invention concerns an electric drive unit with a steering motor and a propulsion motor which are arranged co-axially with one another and which, respectively, steer a wheel of the vehicle or drive it in the sense of propulsive movement. A first motor (1) has a hollow drive shaft (2), through which passes a second drive shaft (3) of the second motor (4). The second drive shaft (3) also extends through an outer wall (5) of the drive unit and, on the outside (6), is connected rotationally fixed to a fan wheel (7), such that air for cooling is blown outside along the housing of the drive unit.

Abstract: A procedure for the circulation of a quantity of oil in an oil circulation system of a transmission of a motor vehicle and also concerns an oil circulation system. A portion of the quantity of the oil, which oil is at a lower temperature and a higher viscosity, is retained in a stationary, porous storage medium, from which, upon increasing oil temperature and lessening viscosity, the oil may be removed and entrained in the existing circulating oil quantity. Preferably, the storage medium is placed within an oil pan.

Abstract: A retarder system for commercial vehicles is provided which consists of a transmission oil circuit (18) for lubrication of the transmission and of a retarder cooling circuit (4) which uses oil as operating fluid, both circuits being coupled via a connection (21) so that in the non-activated braking state of the retarder (1), for increasing the transmission oil flow rate through a radiator (3), oil can be branched off from the transmission oil circuit (18). In addition a retarder pump (12) is proposed which has a prime mover (25), preferably an electrical motor.