Jtekt Corporation

Yuji Okawa

Kunimichi Nakashima

Toshiharu Takashima

Takamasa Shibata

Nobumitsu Hori

Takahito Umeki

Katsuhiro Maseki

Kazunari Ogura

The damping property of a rear rolling bearing () is adjusted by controlling a damping force that is applied by damping application means () based on, for example, the type of a tool (T). Thus, it is possible to provide the optimum damping properties for various tools that differ in natural vibration, and to suppress the generation of chattering of the various tools. As a result, it is possible to increase the cut amount per unit time to increase the productivity.

Spindle device for machine tool

By controlling an amount of preload applied to a rolling bearing that supports a spindle in accordance with the change of state of the spindle in actual machining, the rotation of the spindle is controlled in an optimal state, and the service life of the bearing is extended while the required stiffness of the spindle is ensured. When a corrected preload amount falls outside a range of a preload as a controllable region, the corrected preload amount is corrected so as to fall within the range of the preload. That is, an actually controlled preload is regulated to fall within the preset range of preload. Therefore, it is possible to ensure the stiffness of the rolling bearing or prevent heating and excessive increase in contact pressure of the rolling bearing.

Spindle device

In a main spindle device provided with a housing and a main spindle, a labyrinth-forming annular groove is formed, in the circumferential direction of the main spindle, on the outer circumferential surface of a protruding portion of the spindle that protrudes from the housing on the front side. A housing lid member having a protruding portion that is inserted into the labyrinth-forming annular groove so as not to contact an inside surface of the labyrinth-forming annular groove all around the periphery is fixed to the housing on the front side thereof and forms a labyrinth seal portion between the protruding portion and the labyrinth-forming annular groove. The housing lid member is constructed so that the housing lid member can be divided into at least two pieces with respect to the circumference of the labyrinth-forming annular groove.

Main spindle device

A main spindle device includes: a housing having an air supply passage; a spindle that is inserted into the housing and supported by a bearing so as to be able to rotate relative to the housing; and an air sealing member that is positioned between an outer circumferential surface of the spindle and the housing on a front side with respect to the bearing along a rotation axis of the spindle, has a substantially annular shape, and is detachably fixed to the housing with an inner circumferential surface of the air sealing member facing the outer circumferential surface of the spindle, wherein air supplied from the air supply source through the air supply passage is discharged into a gap between the outer circumferential surface of the spindle and the housing, thereby effecting non-contact air sealing at least between the inner circumferential surface of the air sealing member and the outer circumferential surface of the spindle.

Growing community of inventors

Kariya, Japan

Yuji Okawa