Negative-Poisson ratio structure-based self-adaptive principal axis preload adjusting method

Abstract

The invention discloses a negative-Poisson ratio structure-based self-adaptive principal axis preload adjusting method. According to the method, a bearing inner ring spacer bush adopts a negative-Poisson ratio structure; in the initial assembly stage and the low-speed stage, the bearing inner ring spacer bush is located in a pressed state, unit cells are located in a closed state due to pressing,and the bearing inner ring spacer bush is capable of providing relatively large bearing preloading force and rigidity to a bearing; in the speed raising process of a principal axis, the bearing innerring spacer bush of the negative-Poisson structure generates trace extension in the axial direction under the action of centrifugal force, so that the inner ring of the bearing generates trace deformation or displacement along the principal axis so as to decrease the preloading force of the bearing and then realize the target of having small preloading force under high-speed working conditions; when the rotation speed is reduced, the centrifugal force is reduced, and the axial action of the bearing inner ring spacer bush of the negative-Poisson structure is decreased, so that the bearing is transferred to an initial position and then the pre-loading force of the bearing is enlarged again. The method is a material-based preloading force adjusting method which has the advantages of being simple and reliable, and is a brand-new preloading force adjusting technology.

Description

technical field [0001] The invention relates to the technical field of self-adjustment of spindle pretightening force, in particular to an adaptive adjustment method of spindle pretightening force based on a negative Poisson's ratio structure. Background technique [0002] Preload is one of the key parameters to regulate the service performance of the spindle. Studies have shown that a reasonable preload can increase the rigidity of the spindle by 65%, reduce the temperature at high speed by 41.6%, and increase the limit speed of the spindle by 54.5%. The traditional constant preload cannot fully meet the variable preload requirements of high-speed spindles and wide operating conditions. Therefore, the real-time control technology of the pretightening force of the spindle bearing becomes the key technology of the high-speed spindle. [0003] With the development of high-speed spindles in our country, more and more attention has been paid to the self-adjustment of preload. ...

AI Technical Summary

Problems solved by technology

[0004] The advantage of the current adjustment preload method proposed in the above patent is that the response speed is fast, but the electromagnetic force loading device is limited by the installation space, and the preload adjustment range is small; the proposed automatic adjustment of the preload based on temperature changes , due to the hysteresis of temperature changes, it is difficult to realize the rapid response of the preload force to the change of the spindle operating speed, and the precision of the preload force is also difficult to control, and piezoelectric ceramics also have the problems of easy aging of components and poor reliability

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