Nsk Corporation

Daisuke Kuroiwa

Kazuo Miyaguchi

Kazunari Miyazaki

A method for manufacturing a ball screw according to the present invention includes a seal fixing step of fixing a ring shaped seal to an attachment portion disposed in an end portion of a nut of a ball screw in an axis direction using a fixing member. The attachment portion has an inner circumferential surface having a diameter larger than that of an inner circumferential surface on which a spiral groove of the nut is formed. A through hole is formed in the attachment portion, the through hole penetrating the attachment portion in a radial direction from an outer circumferential surface thereof to the inner circumferential surface thereof. The seal fixing step includes passing the screw through the through hole and engaging the screw with an outer circumferential portion of the ring shaped seal to exert an outward-directed force in the radial direction on the ring shaped seal because of a force of the head pressing the bearing face to fix the ring shaped seal to the nut.

Method for manufacturing ball screw and ball screw

A ball screw device is provided in which a dust-proof member can be simply attached to a nut. The ball screw device () is a ball screw device () in which a concave portion () is formed in an inner circumferential end portion of a nut () through which a screw shaft () passes and the concave portion () is provided with a dust-proof member (), wherein the dust-proof member () is formed of a cylindrical elastic member into which the screw shaft () is inserted and includes at least one protrusion () protruding in an outward diameter direction from an outer circumferential surface of the dust-proof member (), and the concave portion () has a groove shape to which the dust-proof member () is fitted and is provided with a locking portion () to which the protrusion () is locked.

Ball screw device and dust-proof member extracting tool

In a ball screw device which provides a screw shaft including a ball screw groove in the outer peripheral surface, a ball nut including a ball screw groove formed in the inner peripheral surface opposite to the ball screw groove of the screw shaft, a plurality of balls fitted between the ball screw grooves of the screw shaft and ball nut, and a tube type circulation path for circulating these balls, the ball screw device can reduce the moment of inertia of a rotary portion of the device so as to facilitate the use of the ball screw device of a nut rotation type. Further, the ball screw device further provides an oil supplying structure which includes a first oil supplying hole formed in the outer race of the rolling bearing and passing through the outer race from the outer peripheral surface thereof to the inner peripheral surface thereof, and a second oil supplying hole formed in the ball nut, passing through the ball nut from the outer peripheral surface thereof to the inner peripheral surface thereof and also communicating with the first oil supplying hole through an annular gap. The oil supplying structure can supply oil even while the ball screw device is in operation, and eliminate the mounting and removal of an oil supplying pipe when supplying the oil.

Growing community of inventors

Ukiha, Japan

Daisuke Kuroiwa