| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a structure which can measure precompression load applied to angular ball bearings 9a to 9d. <P>SOLUTION: A pair of encoders 5a, 5b are externally engaged with a position which is a part of a main shaft 8 and in which an inner ring 15c constituting an angular ball bearing 9c is clamped by the encoders from the axial direction both sides. Magnetic characteristic of the outer peripheral surface of both of the encoders 5a, 5b is alternately changed in a circumferential direction as well as a border between circumferentially adjacent different magnetic characteristics is inclined with respect to the axial direction. Detectors of sensors 21a, 21b constituting a pair of sensor units 6a, 6b supported by a housing 7 are made to face the outer peripheral surfaces of both of the encoders 5a, 5b. In this state, when compression distortion of the members 5a, 5b, 5c in the axial direction changes in accordance with change of precompression load, phase difference between output signals of both of the sensors 21a, 21b changes. Then, a function for calculating the precompression load based on the phase difference is provided to a computing unit (not shown). <P>COPYRIGHT: (C)2013,JPO&INPIT |
