Rotation-resistance device for machine tool main shaft drive

Abstract

The rotational pulsing of a main shaft drive is limited, and the rigidity of the main shaft is increased without increasing bearing size when a workpiece is finished while rotating using the machine tool main shaft drive. A rotation-resistance device that is configured as described below is provided in the main shaft drive for a machine tool having a main shaft that is supported to be able to rotate relative to frame main body, a rotating body that is fixed to the end of the main shaft, and a drive that rotates the rotating body. The rotation-resistance device has a damping device that has a damping element comprising an elastically deformable damping part provided on the frame main body or the rotating body, a compressive force application device that applies compressive force to the damping element using a working fluid, and a damping surface provided on the frame main body side. The damping device applies compressive force to the damping part, causing flexure, thereby causing the damping surface and a sliding surface to press against each other so that rotational resistance that allows rotation is applied to the rotating body. A low friction coefficient member is fixed to at least the damping surface (32) or the sliding surface.

Description

technical field [0001] The present invention relates to a main shaft driving device in a machine tool that rotatably supports a main shaft supported by a frame body and a member to be driven to be rotated fixed to an end of the main shaft by a driving device. Background technique [0002] There is a device described in Patent Document 1 as one of known technologies related to the spindle drive device in the above-mentioned machine tool. The spindle driving device in the machine tool disclosed in Patent Document 1 is a rotary index table (table) device, and as the driving means of the spindle, a direct-drive motor (so-called DD) that rotates and drives the spindle without a drive transmission means such as a gear motor) is used. [0003] In the rotary indexing table device of the aforementioned Patent Document 1, the clamping state / release state of the table is switched by introduction of the working fluid. The piston system is constantly biased to the brake plate side by t...

AI Technical Summary

Problems solved by technology

[0010] However, if the bearing is enlarged, the vibration accuracy will decrease, and the indexing accuracy will decrease accordingly, resulting in a decrease in machining accuracy.

In addition, since the larger the diameter of the bearing system, the more expensive it is, the manufacturing cost of the device becomes higher.

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