| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ball screw device, in which rolling fatigue life can be extended by improving load capacity and rigidity when moving linearly even if a lead of a shaft side rolling groove of a screw shaft is changed, and which is configured to reduce the manufacturing cost. <P>SOLUTION: The ball screw device includes: the screw shaft 2 provided with a helical shaft side rolling groove 1 formed on the outer circumferential surface; a nut 4 provided with a helical nut side rolling groove 3 formed on the inner circumferential surface; and a plurality of rolling elements 5 which roll between the shaft side rolling groove and the nut side rolling groove. In the device, the precision of the lead of the nut side rolling groove is not changed along the shaft direction and the precision of the lead of a predetermined position in the shaft direction of the shaft side rolling groove is changed. Then, a contact angle between each of the rolling elements 5 and the shaft side rolling groove and a contact angle between each of the rolling element 5 and the nut side rolling groove are set to each predetermined value so that torque does not increase due to a change of the precision of the lead of the shaft side rolling groove. <P>COPYRIGHT: (C)2013,JPO&INPIT |
