| 摘要 |
PROBLEM TO BE SOLVED: To suppress deformation caused by difference in linear expansion coefficients between different materials.SOLUTION: A telescopic actuator includes a feed screw mechanism 48 composed of a male screw member 112 having a male screw portion 112a, and a female screw member 114 engaged with the male screw portion 112a, and converting the rotating motion of a motor 42 into reciprocating linear motion. The male screw member 112 and the female screw member 114 are respectively composed of different materials, and include an auxiliary member 200 of a linear expansion coefficient αin the axial direction, satisfying a relationship of α<α<αwhen a linear expansion coefficient in the axial direction of the male screw member 114 is α, a linear expansion coefficient in the axial direction of the female screw member 114 is α, and a magnitude relationship of the linear expansion coefficients is α<α. The an auxiliary member 200 is integrally coupled inside the male screw member 112 and within an axial range including the male screw portion 112a. |
