Internal and external cooling structure for high-speed motorized spindle

Abstract

The invention provides an internal and external cooling structure for high-speed motorized spindle. According to the structure, cooling water channels are additionally arranged on a casing of the motorized spindle and a front bearing pedestal of the motorized spindle, and a spiral cooling water channel is arranged in the spindle, so that all the main heating components such as a motor stator, a motor rotor, a front bearing and a back bearing of the motorized spindle can be efficiently cooled, therefore, the temperature rising of the motorized spindle is effectively controlled, the service life of a motor and the service life of bearings can be prolonged, and the machining precision and surface machining quality of the motorized spindle are greatly improved by virtue of the reduction of thermal deformation.

Description

technical field [0001] The invention relates to an internal and external cooling structure of a high-speed electric spindle, in particular to a cooling structure for simultaneously cooling the electric spindle internally and externally. Background technique [0002] The main feature of the high-speed electric spindle is that the stator and rotor of the motor are directly installed inside the spindle to form a mechatronic electric spindle. Thus, the "zero transmission" of the spindle system is realized, which has the advantages of compact structure, small moment of inertia, fast start and stop speed, easy to realize stepless speed regulation and precise control, etc. is extremely unfavorable. The built-in electric spindle is mainly composed of a built-in servo motor, front and rear support bearings, a main shaft and a housing, among which the built-in servo motor and the front and rear bearings are the main heating components of the electric spindle. Temperature rise is an ...

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Problems solved by technology

The traditional cooling method is to add a spiral cooling water channel between the motor stator and the shell, and add an annular water channel between the front bearing seat and the shell, and connect it through the water inlet and outlet joints on the rear cover, and the internal cooling The water takes away the heat from the stator and front bearing of the motor to cool the front bearing and stator. However, the rotor and rear bearing, which account for 1 / 3 of the heat generated by the motor, have not been effectively cooled, thus forming an external cooling system for the electric spindle. Phenomenon of internal heat

The thermal expansion of the spindle has a fatal effect on the machining accuracy. If the diameter of the spindle center is calculated as 0.5m, then according to the thermal expansion theory of the metal, if the temperature of the spindle center rises by 1°C, the length of the spindle will extend. The length is 0.005m. If the thermal deformation caused by this is not handled properly, it will seriously affect the machining accuracy and surface processing quality of the electric spindle on the one hand. On the other hand, because the temperature of the outer ring of the bearing is higher than that of the inner ring, the preload of the bearing Increased, further aggravated the wear and heat of the bearing, affecting the service life of the bearing

Aiming at this phenomenon, there is currently a shaft cooling method: a cooling heat pipe is installed on the shell of the electric spindle and the shaft. Although this cooling method can cool the electric spindle to a certain extent, this cooling The cooling medium of this method is not liquid but air. Since the heat exchange power of air is limited, this method cannot effectively solve the heat dissipation problem of the electric spindle under long-term work.

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