BALL SCREW DEVICE

• Main Authors: HAYASHI YUKI, AMEMIYA YOHEI
• Format: Patent
• Language: English; Japanese
• Published: 13.12.2023
• Subjects: BLASTING; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; THERMAL INSULATION IN GENERAL; WEAPONS

To provide a ball screw device capable of realizing smooth ball circulation on an endless circulation passage while forming a circulation groove to an inner peripheral surface of a nut member by cutting work.SOLUTION: A ball screw device includes: a number of balls; a screw shaft having a ball rolling groove spirally formed on its outer peripheral surface; and a nut member having a through hole for inserting the screw shaft, further having a forwarding passage formed on an inner peripheral surface of the through hole for circulating the number of balls only by one round at the circumference of the screw shaft, and engaged with the screw shaft via the number of balls. The forwarding passage has a load rolling groove opposed to a part of the rolling groove of the screw shaft, and a circulation groove connecting both ends of the load rolling groove while crossing a screw thread of the screw shaft. The forwarding passage is provided in adjacent to an opening edge of the through hole of the nut member, and a corner portion where an inner peripheral surface of the through hole and an axial end face of the nut member cross, is provided with an inclination portion formed by cutting out the corner portion with an uneven width along a circumferential direction of the through hole.SELECTED DRAWING: Figure 7 【課題】ナット部材の内周面に対して循環溝を切削加工で形成しつつも、無限循環路における円滑なボールの循環を実現することができるボールねじ装置を提供する。【解決手段】多数のボールと、外周面に前記ボールの転動溝が螺旋状に形成されたねじ軸と、前記ねじ軸が挿通される貫通孔を有すると共に、当該貫通孔の内周面には前記多数のボールを前記ねじ軸の周囲で一周のみ循環させる回送路を有し、多数のボールを介して前記ねじ軸に螺合するナット部材と、を備え、前記回送路は、前記ねじ軸の転動溝の一部に対向する負荷転動溝と、前記ねじ軸のねじ山を横切って前記負荷転動溝の両端を接続する循環溝と、を有し、前記回送路は前記ナット部材の貫通孔の開口縁に隣接して設けられ、前記貫通孔の内周面と前記ナット部材の軸方向端面が交わる角部には、当該貫通孔の周方向に沿って不均一な幅で前記角部を切り欠いた傾斜部が設けられていることを特徴とする。【選択図】 図７