Abstract: A reciprocating vacuum pump characterized in that each part to be lubricated of a crank moving portion and piston moving portions is made oilless, two pistons in the piston moving portions being formed so that their load working lines are aligned, a suction exhaust valve being provided on each of the two pistons. This pump may have a multistage structure in which two pistons extend in a horizontally opposed state. The reciprocating vacuum pump thus constructed is small in size and light in weight, and is substantially free from vibration.

Abstract: An evacuation apparatus comprising (1) a reciprocating vacuum pump, the piston rings and piston shaft sealing material of which are made of a self-lubricating material at least on the surface and in which metallic bellows is or are used to seal between the piston shaft outside the cylinder and the outer face of the cylinder end wall, and (2) a turbomolecular pump in which a casing, stationary blades mounted on the casing, a rotor, and moving blades provided on the rotor are arranged coaxially, and in which the delivery opening of the reciprocating vacuum pump is open to the atmosphere and the suction opening of the turbomolecular pump is joined to an apparatus to be evacuated.