Patent ID: 8888630

Claim:
An oil pump driving mechanism having a linking mechanism that links a first sprocket, which is linked by a chain to a second sprocket that drives an oil pump disposed in a radially detached position from a rotary shaft of a torque converter and rotates about the rotary shaft of the torque converter, and an engaging pawl of the torque converter, wherein the linking mechanism comprises: a recessed portion which extends axially from a side face of the first sprocket facing the torque converter and into which the engaging pawl of the torque converter is inserted; and a friction reducing mechanism provided on at least one of the side face and the engaging pawl, wherein the side face is cone-shaped and is tilted relative to an end face of the engaging pawl, wherein the end face and the side face are configured to contact each other at a point contact without surface contact, such that a contact area between the side and end faces is reduced, and wherein the first sprocket is rotated by a torque converter sleeve through the engaging pawl.