| 摘要 |
An eddy current or ultrasonic detector is mounted in a rotatable head (44) secured to an axial extension (42) of a hollow rotor (40) axially held in one chamber (36) of a cylindrical housing (12). The bore of the rotor receives an axial extension (32) of a piston (20) reciprocable in a second chamber (14) of the housing under the opposed action of the pressure of a fluid supplied from a conduit (66) and a spring (60). Balls (72) engage in both a helical groove in the piston extension (32), and an axial groove (74) in the rotor (40) , to produce rotation of the latter upon axial movement of the piston. |
