| 摘要 |
PURPOSE:To make the value of pre-loading always optimum by detecting temperature, vibration, number of revolution, initial pre-load, actual pre-load, etc. inside a spindle including a rotating part,and controlling a means of giving pre-load depending on the detected value. CONSTITUTION:An FM telemeter transmitter 63 is installed on the outer peripheral part of a rotary shaft 10, and and FM telemeter receiver 64 is installed on the inside part of a housing 30, close to the transmitter 63, in a spindle unit. A hole 65 which is opened radially through the peripheral part of the rotary shaft 10 in a position in contact with, or close to, a bearing inner race 21. And, a temperature sensor 61 is installed in this hole 65 and a pre-load sensor 62 is provided in a notch part formed on a part of the bearing inner race 21. Besides, a bearing outer race sensor 57 and a rotation sensor 59 for the rotary shaft 10 are provided and the signals of these sensors are inputted in a microcomputer 54, to control the oil pressure of a hydraulic pump 56. |
