A lubricating system has a housing formed with an intake passage, a drive shaft extending longitudinally in the housing and carrying a plurality of longitudinally spaced worm gears, and respective pumps juxtaposed with the worm gears in the housing. Each pump has a cylinder fixed in the housing, centered on a respective transverse axis, and forming an intake port connected to the passage and an output port. A cavity-forming piston is rotatable about and reciprocal along the respective transverse axis and a worm wheel on the piston meshes with the respective worm gear. An axially projecting cam ramp on the worm wheel is axially engageable with an abutment on the housing. This abutment can be moved axially and for fixing it in any of a multiplicity of positions for varying axial deflection of the piston. A spring bearing against the piston urges the ramp toward the abutment. Rotation of the shaft rotates and reciprocates the piston for drawing in a lubricant at the intake ports and expelling it at the output ports so that the range of axial movement of the piston and the amount of lubricant pumped are determined by the axial deflection of the piston by the ramp.