Patent ID: 6969235

Claim:
An air turbine starter comprising: a first housing defining an air inlet, an air outlet and a flow path therebetween; a second housing coupled to the first housing to enclose a gearbox and an output shaft coupled to the gearbox; a turbine wheel having circumferentially mounted blades disposed in the flow path of the first housing; a rotatable turbine drive shaft coupled to the turbine wheel and extending into the second housing to drive the gearbox, the turbine shaft being supported by at least one bearing characterized by: a plurality of balls, each ball having a uniform diameter (â€œDâ€) and a longitudinal centerline; a radially inner ring having a first shoulder, a second shoulder and a race surface therebetween to receive the balls, the first and second shoulders each having a radial height, the first shoulder radial height being less than the second shoulder radial height; a radially outer ring having a first shoulder, a second shoulder and a race surface therebetween, the first and second shoulders each having a radial height, the first shoulder radial height being greater than the second shoulder radial height, and wherein the outer ring is located concentrically about the inner ring, with the balls therebetween, in a plane generally perpendicular to a predetermined axis of rotation, the longitudinal centerline of each ball parallel to the axis of rotation; an annular cage located between the inner and outer rings and having openings to receive and separate the balls nested between the inner ring race surface and the outer ring race surface; and an oil circulation system to flow oil in a direction flowing from the first shoulder of the outer ring toward the second shoulder of the outer ring.