Abstract: In a gear pump with variable throughput volume, with two meshed gears with external toothing which are rotatably held in the working chamber of a pump housing, at least one of the two gears is driven from a drive shaft and one of the gears, preferably the driven gear, is shiftable in the direction of its axis. In order to realize a control mechanism in a simple manner a gap width defined as the distance measured in axial direction between an essentially plane first interior side wall of the working chamber of the pump housing and a first front face of the shiftable gear, is designed to be variable.

Abstract: A clutch element for a unit is driven via a drive shaft, especially for a water pump. The clutch element comprises a temperature- and/or speed-sensitive clutch member which is rigidly connected with the drive shaft and which acts on a part of the unit to be driven depending on the temperature and/or rotational speed, with the clutch member being formed by a clutch disk whose surface forms at least one clutch surface for non-positive connection with a respective counter-surface which is formed by a surface of the part to be driven. At least one clutch surface comprises at least one drainage groove.