Bearing variable preload system utilizing gap between strokes for preload adjustment and elastic deformation of sealing member

Abstract

A bearing variable preload system utilizing gaps between strokes for preload adjustment and elastic deformation of a sealing member, according to the present invention, comprises: a housing; bearings provided to the housing; a spindle coupled to the inner wheels of the bearings so as to rotate; and a variable preload unit provided to the housing and applying a variable preload to the outer wheels of the bearings, wherein the variable preload unit has a chamber of which the airtightness is maintained by a sealing member between a pressing member coming into contact with the outer wheel of the bearing and the bearing housing part and a pressure supply unit for supplying air pressure or oil pressure to the chamber through a supply pipe provided to the housing so as to vary a preload applied to the outer wheel of the bearing. The spindle having the preload system, according to the present invention, has the effects of improving rigidness, preventing heat, reducing noise and vibration, extending the lifespan of the bearing or the like.

Description

technical field [0001] The present invention relates to a variable preload system for bearings, and more specifically, to a system for applying constant pressure and variable preload to an outer ring of a bearing supporting a high-speed rotatable spindle, which utilizes stroke clearance and variable preload to adjust the preload. Variable preload system for elastically deformable bearings of sealing material. Background technique [0002] The performance of the machine tool spindle system and the life of the bearings are affected by the preload applied to the bearings. When the preload is appropriately changed according to the number of revolutions and operating conditions, the vibration of the spindle can be reduced. Moreover, when a preload is applied to the spindle of the machine tool, not only can the surface illumination of the finished product be improved, but also heat generation of the spindle can be suppressed and the life of the spindle can be extended. Therefore,...

AI Technical Summary

Problems solved by technology

[0013] First, there is a structure in which a bearing sleeve is provided between the outer ring of the bearing and the housing, so in order to adjust the preload of the bearing, the point of action acting on the outer ring of the bearing is inclined outward, making it difficult to accurately apply preload to the outer ring of the bearing

[0014] Second, because a sleeve is provided between the outer ring of the bearing and the housing, the main shaft becomes relatively large or the bearing supporting the mandrel becomes small

When the bearing is reduced, although the allowable rotational speed of the bearing increases, the acting preload becomes smaller. Due to the difference in specifications of the upper and lower bearings, the life of the smaller bearing becomes shorter when considered in terms of preload.

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