The subject matter described herein relates to a spin pump that includes a combination of a compressor and a vacuum pump on respective pistons extending from a common crankshaft in a rotating housing. Related methods, apparatuses, systems, techniques and articles are also described.

An axial variable displacement piston pump includes a drive shaft disposed on an axis, a piston barrel comprising a plurality of pistons disposed about the drive shaft, and a swash plate disposed about the drive shaft. Each of the piston barrel and the swash plate are rotationally coupled to the drive shaft such that the drive shaft is configured to simultaneously drive rotation of each of the piston barrel and the swash plate.