Sealing device for oil rotary vacuum pump.

摘要

A sealing device of an oil rotary vacuum pump of the type which includes a rotar (2), a cylinder (4) accommodating the rotor, the cylinder having a suction port and a discharge port, a cylinder end cover (5), a rotor shaft (6) passing through the end cover, an oil casing (1) attached to the end cover such that it encloses the cylinder and contains a space (22) above the oil, and a rotor shaft bearing (7) in the end cover. The sealing device includes: a pair of sealing members (8) mounted on the rotor shaft and provided in the end cover, spaced to form a gap (17) and located on the side of the bearing (7) remote from the rotor; an oil reservoir (9) between the bearing and the sealing member closer to the rotor; a first passage (11) connecting the oil reservoir (9) with the interior of the cylinder in the vicinity of the discharge port; a lubricant in the gap (17); and a second passage (18) connecting the gap (17) to the space (22) in the oil casing.