To provide a ball spline improving the service life by preventing edge stress when the moment is applied.
A ball spline outer cylinder 4 is formed in a barrel shape, and is fitted in a cylindrical surface 16 formed in an inner periphery of a housing 6 through a cylindrical elastic supporting body 13 having a cylindrical outer peripheral surface 22 and a barrel shaped inner peripheral surface 21. Key grooves 17 and 18 are respectively formed on an outer peripheral surface 15 of the ball spline outer cylinder 4 and the inner peripheral surface 16 of the housing 6, and an inward protruding part 23 and an outward protruding part 24 fitted in the key grooves 17 and 18 are provided on the outer peripheral surface and the inner peripheral surface of the elastic supporting body 13.
Einosuke Kishimoto
Akira Watanabe
Matsumura Naoto