| 摘要 |
PURPOSE:To enhance positioning accuracy, by setting a diameter of a rolling element between a contact surface and a guideway so as to cause a moving body's position to be kept constant to waviness on the guideway of wavelength of more than the overall length of the guideway. CONSTITUTION:When a moving body 5 is moved by driving force of a linear motor 12, a rolling element group moves as far as one a half of travel of the moving body 5. At this time,a first rolling element 4a and a second rolling element 4b are situated in position between a first contact surface 13 of the moving body 5 and a guideway 2. And, a fourth rolling element 4d and a fifth rolling element 4e are situated in position between a second contact surface 14 of the moving body 5 and the guideway 2. At the time of movement, a guideway 2a opposite to the second contact surface 14 of the moving body 5 is more protuberant than a guideway 2b opposite to the first contact surface 13 of the moving body 5, but the mean value of each diameter of these first and second rolling elements 4a and 4b is larger than that of these fourth and fifth rolling elements 4d and 4e. With this constitution, a positional change due to wavy height variations in the moving body 5 is compensated. |
