CALIBRATED MECHANICAL ORTHOPEDIC DRIVER WITH WEAR-COMPENSATED TORQUE-LIMITING MECHANISM

摘要

A torque-limiting driver (10) for orthopedic surgical use has a housing (16) to which a torque force may be applied and transferred to a driver output shaft (18). The housing (16) encloses a cam bearing assembly (52) having a ball cage (54) disposed so that balls (56) of the ball cage (54) moves along a first vector path (Vr) radial to the axis of rotation (20). The bearing assembly also has an inner race (58) abutting the ball (56) and which inner race (58) travels along a second vector path (F) parallel to the axis of rotation (20). The first vector path (Vr) and the second vector path (F) are not co-axial. A bearing load assembly (70) applies a bias force (F) to the inner race (58) of the cam bearing assembly (52) to set the calibrated maximum amount of torque that can be transmitted via the housing (16) through the cam bearing assembly (52) to output shaft (18) of the torque-limiting driver (10).