| 摘要 |
PROBLEM TO BE SOLVED: To provide a double row spherical roller bearing whose thermal deformation of a guide ring is suppressed, that is caused by hardening and tempering treatment. SOLUTION: A manufacturer produces a guide ring 13 of specified measurement and shape by forging, cutting and the like and then oil-hardens the guide ring 13 with specified heating treatment and hardening temperature. In such a case, some camber or distortion occurs at the guide ring 13 due to uneven cooling, etc., at the time of hardening. Afterward, the manufacturer fits the guide ring 13 to a cylindrical first correction mold 31. The guide ring 13 is sandwiched by a circular second correction mold 33 and a disc-like third correction mold 35 from upper and lower sides. Next, the manufacturer carries current to a high frequency heating coil 31 through a tempering control device, and heats the guide ring 13 to a specified tempering temperature while watching it through a thermometer 39. The guide ring 13, temporarily showing plasticity at its system, is corrected in its camber or distortion in the first to third correction molds 31, 33, 35. |
