Hermetically encapsulated rotary piston compressor with horizontally disposed, at least partially hollow crankshaft. The lubricating oil is sucked up by a dynamic vacuum created in a compressed gas line, out of an oil sump, by means of an oil suction pipe, and is conveyed together with the compressed gas into the hollow part of the crankshaft, which has inside the cylinder housing radial bores for oil supply to the moving parts of the compressor. According to the invention, the oil suction pipe is mounted for rotation about the axis of the crankshaft. Thereby the oil supply is maintained in any position resulting from any rotation of the compressor about the horizontal axis of its crankshaft.