| 摘要 |
PROBLEM TO BE SOLVED: To provide a piece type ball screw equipped with a piece member having contradictory characteristics of strength, durability and toughness. SOLUTION: The piece type ball screw is equipped with a screw shaft 1 provided with a spiral thread groove 2 on the outer surface, a nut 3 externally fitted to the screw shaft 1 and provided with a spiral thread groove 4 on the inner surface, a plurality of balls 5 accommodated in a rolling passage formed by two facing thread grooves, an arm 9 fitted to a piece window 6 bored in a barrel part of the nut 3, provided with a coupling groove 8 taking the rolling passage as a revolving passage and positioned by being engaged with the screw groove 4 of the nut 3, and a piece member 7 integrally provided with a guide wall 11 caulked and fixed to both side edges of the piece window 6. The piece member 7 is molded by MIM, formed by precipitation hardening stainless steel having toughness allowing plastic deformation of the guide wall 11, and hardened by solution heat treatment, wherein the surface hardness is set to 30 HRC or higher. COPYRIGHT: (C)2006,JPO&NCIPI
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