Abstract: The invention relates to a plate heat exchanger that consists of several pieces of sheet metal that are arranged parallel to one another, that are at least partially corrugated and that form a considerable number of heat-exchange passages. A header creates a flow connection among at least some of the heat-exchange passages. At least two parts (1, 2, 3) of the plate heat exchanger consist of metallic materials that cannot be welded to one another.

Abstract: A drive for selectively driving a wheel hub which includes a motor with a hollow output shaft driving a planetary gear train with a sun wheel on the hollow output shaft. An output element is fixed to a portion of the wheel hub and a multi-plate clutch or brake selectively connects and disconnects the wheel hub and the hollow output shaft. An axially movable rod operates the clutch or brake and pressurized hydraulic fluid and a spring shift the rod axially to connect and disconnect the clutch or brake to control rotation of the wheel hub by the motor.