| 摘要 |
PURPOSE:To always keep the center of rotation at a specified position by a method wherein displacement sensors are arranged at one of a pair of magnets and another pair of magnets and a mean value of sensed values of the displacement sensors arranged at a pair of magnets is compared with each of the sensed values as a displacement reference value. CONSTITUTION:Displacement sensors 3y and 3y' are arranged at a pair of magnets 2c and 2d, and a displacement sensor 3x is arranged at a magnet 2b, the sensed values deltay1, deltay2 of the displacement sensors 3y, 3y' are applied to an adder 9 and a multiplier 10 to get a mean value deltam, and the mean value deltam and the sensed value deltay1 of the displacement sensor 3y are compared with the sensed value deltax of the displacement sensor 3x by the comparators 11 and 12 and then an exciting current is controlled by the control devices 14y and 14x in such a way as each of the sensed values deltay1, deltax is equal to the reference value deltam. Thereby, it is possible to correct a clearance standard in response to an expansion caused by an increased temperature of the rotating shaft 1, so that it is possible to keep always the center of rotation at a specified position with a rapid response to the operating condition. |
