US Patent 7210565 Torque transmission apparatus and case structure

In order to make it possible to shorten an entire length, a torque transmission coupling is provided with a rotating shaft (11) and a drive pinion shaft (17) for carrying out input and output transmission of a torque, and a torque control means (125) arranged between the rotating shaft (11) and the drive pinion shaft (17) and controlling a torque transmission between the rotating shaft (11) and the drive pinion shaft (17) on the basis of a frictional engagement caused by an electromagnetic force of an electromagnet (133), and at least a part of the torque control means (125) is arranged in an outer periphery of a taper roller bearing (117) rotatably supporting the drive pinion shaft (17).