| 摘要 |
PROBLEM TO BE SOLVED: To provide an end cap type ball screw unit in a simple structure, which is mass-produced at low costs. SOLUTION: The end cap type ball screw unit comprises a screw shaft 1 forming a spiral groove 11 on the outer periphery, a nut 2 having a large diameter portion 22 expanding toward an outer diameter side in an axially central portion and a spiral groove 21 opposite to the spiral groove 11 of the screw shaft 1 on the inner periphery and a return passage 24 axially passing through to the large diameter portion 22, a pair of end caps 3 and 3 externally fitting on small diameter portions of the nut 2 at both sides and having a turn passage 33 connecting together between both opposing spiral grooves 11 and 21 and the return passage 24, and multiple balls 4 circulatingly arranged therein while rolling over both opposing spiral grooves 11 and 21, the turn passage 33, and the return passage 24. The outer surface of the small diameter portion of the nut 2 is also used as an inner raceway of balls rolling over the turn passage 33. COPYRIGHT: (C)2004,JPO
|
