Ball Screw Device

摘要

There is provided a ball screw device having a cooling mechanism of efficiently cooling down a bearing device supporting a screw shaft of a ball screw or vicinities of the bearing device. For this purpose, the ball screw device (1) includes the ball screw (10) and a bearing device (101) supporting at least one end of the screw shaft (110). The bearing device (101) includes a housing (130) rotatably supporting the screw shaft (110). The housing (130) has plural cooling through holes (170) penetrating in the axial direction and allowing passage of a cooling medium. In addition, a combination type of rolling bearings (120A, 120B) of the bearing device (101) is to be a DB type (back face combination type), which is a system of applying a preload by adding a compressive force in the axial direction to the inner ring side of the rolling bearings (120A, 120B).

主权项

1. A ball screw device, comprising:
a nut having a spiral groove formed on an inner circumferential surface; a screw shaft having a spiral groove formed on an outer circumferential surface; balls loaded in a raceway formed with the spiral groove of the nut and the spiral groove of the screw shaft; and a bearing device configured to support an end of the screw shaft, the bearing device comprising: a plurality of bearings having inner rings fit with the end of the screw shaft and rotating integrally with the screw shaft, and outer rings rotatably supporting the inner rings via a plurality of rolling elements arranged on outer circumferential surfaces of the inner rings; and a housing having an inner circumferential surface abutting with the outer circumferential surfaces of the outer rings and rotatably supporting the screw shaft, wherein a plurality of cooling through holes penetrating through both ends of the housing for allowing passage of a cooling medium are arranged in an axial direction of the housing.