Lubricant gear pump and control piston

The invention relates to a lubricant pump (1), in particular for an internal combustion engine of a motor vehicle, comprising a housing (3) in which at least one pair (4) of intermeshing gear wheels (5) is disposed for delivering lubricant, wherein a first of the gear wheels is rotatably mounted on a drive shaft and the second of the gear wheels (5) is rotatably mounted on an axially displaceable displacement unit (6) for adjusting a variable volume to be delivered, and further comprising a control piston (16) which can be moved axially in a receptacle (15) of the housing (3) for hydraulically adjusting the position of the displacement unit (6), wherein the control piston (16) has a central longitudinal shaft (17) and cylinder rings (18-21) enclosing control edges (18', 18"; 19', 19") for exposing or closing control channels (12, 13) opening into the receptacle (15). The control piston (16) is designed as a composite component (31), wherein the cylinder rings (18-21) are produced from a material which reduces friction and/or wear with respect to the receptacle (15), and the central longitudinal shaft (17) is produced at least in some sections from a material which has a coefficient of thermal expansion that corresponds at least substantially to that of the receptacle (15). The invention further relates to a control piston for a lubricant pump.