A rotary rolling piston type compressor having a cylinder mounted in a hermetic shell and a rolling piston driven by a crankshaft carried by the rotor of an electric motor whose stator is fixed internally to the shell. An external part of the cylinder has a radial slot that houses a slidable vane which defines with the cylinder and the piston compression and a suction chamber. The vane surface facing the suction chamber has a planar surface on its upper portion parallel to the vane surface facing the compression chamber and the lower portion of the surface facing the suction chamber has a relieved, or chamfered, section(s). The chamfered surface(s) develops a hydrodynamic wedge effect upon the vane during downward displacement, increasing the lubricating and stability capacity of the vane against the wall of the slot in which the vane slides, and reduces the area of the vane which is in actual contact with the wall of the slot.