High-speed magnetic suspension electric main shaft for five-freedom numerically-controlled machine tool

Abstract

The invention discloses a high-speed magnetic suspension electric main shaft for a five-freedom numerically-controlled machine tool. The electric main shaft comprises a rotating shaft (1) installed on a steel cylinder, a two-freedom magnetic suspension asynchronous motor and two three-freedom alternating and direct current hybrid magnetic bearings, wherein the two-freedom magnetic suspension asynchronous motor is installed on the rotating shaft (1) through a two-freedom magnetic suspension asynchronous motor rotor (18); the two three-freedom alternating and direct current hybrid magnetic bearings are symmetrically installed on the rotating shaft (1) on the two sides of the two-freedom magnetic suspension asynchronous motor through three-freedom alternating and direct current hybrid magnetic bearing rotors (12); and any one of the three-freedom alternating and direct current hybrid magnetic bearings is combined with the two-freedom magnetic suspension asynchronous motor to form a five-freedom magnetic suspension asynchronous motor. The high-speed magnetic suspension electric main shaft has the beneficial effects that no lubrication is required, the axial space is reduced, the structure is symmetrical, the five-freedom magnetic suspension asynchronous motor can be flexibly formed, the non-failure operation time can be greatly improved on the premise of high-speed operation, and the energy loss is reduced.

Description

technical field [0001] The present invention combines the magnetic levitation asynchronous motor, the magnetic bearing and the electric spindle of the numerical control machine tool to construct a new type of high-speed magnetic levitation electric spindle of the five-degree-of-freedom numerical control machine tool. It is a new product that integrates advanced technology and digital control technology, involving electrical engineering, mechanical engineering, control engineering and other scientific fields, and can be widely used in CNC lathes, CNC milling machines, CNC grinding machines, various high-speed centrifuges, high-speed rotary mills, high-speed Testing machine etc. technical background [0002] At present, domestic and foreign CNC machine tool electric spindle support bearings mainly include dynamic and static pressure bearings, ceramic bearings and magnetic bearings and magnetic suspension bearings. Due to the limitation of the surface speed of the rolling elem...

AI Technical Summary

Problems solved by technology

Due to the limitation of the surface speed of the rolling elements in the bearing, the dynamic and static pressure bearings cannot reach the expected high speed and ultra high speed; the ceramic bearing can increase the maximum speed by 20%~30%, but the life of the bearing is short, only a few thousand at most. Hours; the magnetic bearing speed is 5 000~80 000r / min high, the service life is long, and it can run for tens of thousands of hours, but there are still the following problems in different application fields: On the one hand, the magnetic bearings support the motor because the magnetic bearings installed at both ends of the motor occupy A certain length leads to an increase in the axial length of the motor, which increases the difficulty of high-precision control and limits the critical speed and output power of the motor; Expensive displacement sensors and high-quality digital controllers are bulky and costly, which greatly affects the range and wide application of high-speed motors supported by magnetic bearings

Images