Supercharger vent

Claim 1

A rotary blower comprising: a housing defining a rotor chamber and a gear chamber separated by a wall; first and second meshed lobe rotors each disposed for rotation about an axis thereof in the rotor chamber for transferring a gaseous fluid from a housing inlet to a housing outlet; first and second rotor shafts respectively affixed to and extending from the first and second rotors along the axis thereof and into the gear chamber through openings in the wall; first and second meshed timing gears respectively affixed to portions of the first and second rotor shafts in the gear chamber; an input drive shaft extending along an axis thereof from an end exterior of the housing through an input drive opening defined by the housing and into the gear chamber for rotatably driving the timing gears; a lubricating oil disposed in the gear chamber to a level wherein rotation of the gears slings the oil; bearing means rotatably supporting each of the shafts in the opening associated therewith; dynamic seal means, associated with each of the openings and the shaft extending therethrough, for sealingly separating the chambers from each other and the gear chamber from the housing exterior; characterized by: vent passage means in the input drive shaft for venting the gear chamber to the exterior for preventing pressure build up in the chamber, the passage means having one end thereof opening into the gear chamber, an opposite end thereof opening into the exterior, an elongated passage intercommunicating the ends, and a portion of the elongated passage leading to the one end extends radially with respect to the axis of the input drive shaft.