| 摘要 |
<p>PURPOSE:To prevent the oil film cut on a raceway and lengthen the life by consisting of an electromagnetic clutch, a clutch hab, a rotor, and a ball bearing, and making the residual austenite amount in at least one bearing ring of the inner and outer rings of the ball bearing less than 10%. CONSTITUTION:An electromagnetic clutch is formed of a ball bearing 1 supporting a rotor installing a friction material, a clutch hab 4, and a stater 6 having an electromagnetic coil 5. Either of the bearing rings of the ball bearing 1 is subjected to subzero treatment and tempering at 250-380 deg.C to make the residual austenite amount less than 10%. Thus, the contact area of a ball in the ball bearing 1 with the raceway surface is never changed even by receiving a high herze stress in high speed rotation, so that the frictional force, deterioration of the increased greese in heat generation, and an oil film cut on the raceway surface are prevented, resulting in an improvement in the life.</p> |
