Abstract: A rotary blower (26) includes a torsion damping mechanism for transmitting torque from an input drive (48) to a first timing gear (62), the mechanism including an input hub (52), an output hub (64), and a torsion spring (70) having an input end (72) and an output end (74). The housing (42) defines a chamber (44) containing fluid rotation of the timing gears resulting in an air-oil mist. The input hub and output hub define an axial gap (82) intermediate the input and output ends of the torsion spring. The output hub (64) defines an angled passage (86) having a radially outer end (84) in communication with the axial gap (82), and a radially inner end, whereby rotation generates a flow of the air-oil mist through the angled passage (86) and between the outer cylindrical surface of the hubs and the inside surface (76) of the torsion spring (70).

Abstract: A rotary blower (26) of the Roots type, used as an engine supercharger, comprising a housing (50,52) including a forward wall portion (52F) defining an inlet port (30) disposed toward the upper portion of the housing. Typically, the housing defines an outlet port (34) on the underside (54) of the blower. Disposed within the housing is a pair of meshed, lobed rotors (28,29), with one of the rotors being driven by an input shaft (62). The blower includes a pair of timing gears (58,60) disposed adjacent the rearward end (52R) of the housing. The housing includes an inlet duct (32) disposed above the input shaft (62) and extending forwardly and transversely (FIG. 2) from the housing, and having a duct opening (70) in open communication with the inlet port (30). The arrangement of the invention provides substantially improved air flow efficiency through the blower, which corresponds to improved horsepower output of the engine on which the rotary blower is being used.

Abstract: A rotary blower (26) of the type used for supercharging a vehicle internal combustion engine includes an inlet housing (48) defining an inlet port (30) and an outlet port (34). The blower housing defines a bypass passage (38), through which outlet port fluid is bypassed back to the inlet port (30) whenever supercharging of the engine is not needed. The blower housing also defines a bypass bore (52) open to the exterior of the housing and intersecting the bypass passage (38). A bypass module (54) is disposed within the bypass bore (52) and includes a housing assembly (55). Within the bypass module (54) is a bypass valve member (92) which, in the subject embodiment, includes a cam portion (96), whereby the bypass valve (92) may be actuated by axial movement of a diaphragm (64) and a lever (74). The bypass module (54) cooperates with the housing (48) to define a retention arrangement (100-106), whereby the module is merely inserted into the bore (52), rotated to its assembled position (FIG.