Numerically controlled machine tool motorized spindle with thermal elongation suppression and method thereof

Abstract

This invention discloses an electric spindle for CNC machine tools and a method thereof for suppressing thermal expansion, relating to the field of electric spindle technology. The invention includes a steel cylinder containing a rotor assembly. A front bearing housing is fixed to the bottom of the steel cylinder, and a front bearing outer sleeve is fixed to the lower outer wall of the front bearing housing. A bearing pressure plate is fixed to the bottom of the front bearing housing. A front inner spacer ring is provided on the lower outer wall of the rotor assembly. A preload ring and a preload cover plate are sequentially arranged from top to bottom on the outer side of the front inner spacer ring. A spacer ring assembly is provided at the bottom of the preload cover plate. Oil injection holes are provided on the sides of the preload ring and the preload cover plate that are far apart from each other. The cooling path of the spindle in this invention combines a ring-shaped double-flow loop formed by four fixed rings with an axial flow cooling loop formed by grooves A and B of the steel cylinder, which can effectively improve the torque output of the spindle and enhance its performance stability under high load and high speed.

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