| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a single-line ball screw supporting multipoint contact ball bearing, achieving space saving while maintaining performance similar to that of a conventional combined angular ball bearing. SOLUTION: An inner ring 32 for supporting a ball screw stem is constructed by a pair of raceway halves 32A, 32B each forming a raceway surface in contact with rolling elements 33. Thus, even a single line configuration can support loads in both the axial directions, as well as the combined angular ball bearing. Preload can be added internally by reducing a preload gap W2 formed between the raceway halves 32A, 32B, whereby the rigidity of the ball screw supporting three-point contact ball bearing 3 is increased, enabling precise positioning. Since the ball screw supporting multipoint contact ball bearing has high probability of damaging the surface due to wear or seizure, the rolling element 33 is formed of a martensitic stainless steel having a highly hard nitride layer on the surface.</p> |
