A swash pump for compressible fluids uses sealing contacts made between the nutatable swash plate and the fixed cone plates to center and locate the inner swash sphere which slides against two resiliently mounted ring seals only, minimizing pump friction. A slanted end of a common drive shaft supporting and turned by the rotor of an integrated, variable speed motor causes nutation of the sphere. All bearings, especially axially slidable roller bearings inside the sphere, may settle in position with respect to the common shaft for least frictional loss. This pump is also adapted for pumping explosive gases.