| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball screw for allowing quick determination of whether abnormality occurs inside or not without the need for installing other components than indispensable components for the ball screw, and wirings.SOLUTION: A ball screw 10 includes a screw shaft 1, a nut 2, a plurality of balls 3, and end caps 4. A spiral groove 11 of the screw shaft 1 and a spiral groove 21 of the nut 2 form a rolling path where the balls 3 roll in loaded conditions. The nut 2 has a through-hole 22 passing therethrough in the axial direction. The end caps 4 are components which are fixed to the axial ends of the nut 2 to constitute a ball return path 45 together with the through-hole 22. The balls 3 are arranged in the rolling path and in the ball return path 45. Each of the end caps 4 has a tongue 43 arranged in the spiral groove 11 of the screw shaft 1, and it is formed of a resin composition containing inorganic pigment whose color is reversibly changed with temperature, and synthetic resin. |
