| 摘要 |
PURPOSE:To broaden the surface of shearing movement of roller and the spherical surface of central body of spider and thus prevent the displacement of roller and the vibration of spider by forming circular concave part around the trunnion and making it possible to make a part of roller go into the concave part. CONSTITUTION:On the three trunnions 5 is mounted roller 6 so that it can do shearing movement, while on the spherical surface of central body of spider 3 touches tripod spring 12 with pressure. Around each trunnion 23 circular concave part 25 is formed and further projecting part 34 is formed on the edge surface inside roller 31 in such a way that the part 34 can go into concave part 25. Accordingly, in the state that the minimum pitch P formed by central body and roller 31 is secured to be a set value, distance H3 made between the apex of spherical surface 26 of central body and its edge surface 24 and width M3 made by inserting part 32 of roller 31 overlap with each other, thus making it possible to set the setting sphere of spherical surface 26 of central body and inserting part 32 of roller 31 widely enough. |
