| 摘要 |
PURPOSE:To make it possible to obtain a stable pre-load irrespective of the taper angle of a taper roller bearing, by providing a control means for controlling the speed of a single rotation drive source so that the difference in rotational speed between the inner and outer races of the tapered roller bearing has a reverse relation to the large and small relation between tapered angles. CONSTITUTION:If a tapered roller bearing 2 has a tapered angle theta1, when the inner shaft of a rotary drive head 10 is rotated at about 200r.p.m. while the outer shaft 12 is rotated at about 100r.p.m., a pinion nut 7 is fastened to a driven pinion shaft 4 at about 100r.p.m. Meanwhile when the fastening of the pinion nut 7 is progressed, the value of pre-load is also increased. However, the increase of the pre-load causes a rotating torque to be applied to a housing 1 for a workpiece W, and the value of the torque is measured by a strain gage 32 so that the pre-load may be calculated. Further, when the value of the pre- load reaches a predetermined set value, a controller 26 detects such a condition and stops a motor 25, and therefore, a predetermined pre-load for the housing 1 is stably given to the drive pinion shaft 4 of the workpiece W. |
