Patent ID: 8042526

Claim:
A rotary blower including a housing; first and second rotors disposed in the housing and having meshed lobes for transporting air from an inlet port to an outlet port; first and second shafts rotatably supported by the housing and having the first and second rotors fixed for rotation therewith; first and second timing gears fixed for rotation with the first and second shafts for preventing contact of the meshed lobes; an input pulley adapted to be rotatably driven about an axis; and a torsion damping mechanism operably associated with the input pulley, the torsion damping mechanism comprising: a torsion spring; an input hub adapted to engage a first end of the torsion spring; an output hub adapted to engage a second end of the torsion spring; an intermediate hub disposed proximate the output hub, wherein the intermediate hub includes a circumferentially extending flange; and a bearing member disposed between the output hub and the intermediate hub, wherein the output hub, the bearing member, and the intermediate hub are concentric, wherein an axial end of the bearing member is configured for engagement with the circumferentially extending flange of the intermediate hub, and wherein the bearing member has an inner portion connected for rotation with the intermediate hub and an outer portion connected for rotation with the output hub, and wherein the bearing member is a one-way bearing that permits torque to flow from the output hub into the intermediate hub when the output hub is driven in a first rotational direction, and permits the output hub to rotate relative to the intermediate hub with no substantial torque transfer therebetween when the output hub is driven in a second rotational direction opposite the first rotational direction.