An electric spindle supported by a five-degree-of-freedom alternating current six-pole active magnetic bearing

Abstract

The invention discloses an electric spindle supported by a five-degree-of-freedom alternating current six-pole active magnetic bearing, comprising a three-degree-of-freedom active magnetic bearing, ahigh-speed spindle motor, a two-degree-of-freedom active magnetic bearing and a rotating shaft. The rotating shaft, a rotor of the three-degree-of-freedom active magnetic bearing, the high-speed spindle motor and a rotor of the two-degree-of-freedom active magnetic bearing are fixedly connected in a pivoted manner. Both of the three-degree-of-freedom active magnetic bearing and the two-degree-of-freedom active magnetic bearing adopt three-phase inverter drive cotnrol, which significantly reduces the power consumption and cost of the power amplifier circuit. Both active magnetic bearings adoptsix-pole structure in the radial direction, which greatly reduces the nonlinearity and coupling relationship of levitation force characteristics and makes it easier to achieve accurate control. The invention realizes frictionless rotation between the motor and the rotating spindle, and has the advantages of no mechanical friction and wear, no noise, low power consumption, high speed, high precision and the like.

Description

technical field [0001] The invention belongs to the field of electromechanical transmission, and relates to a non-mechanical contact type magnetic bearing electric spindle, in particular to an electric spindle supported by a five-degree-of-freedom AC six-pole active magnetic bearing, which is suitable for high-speed, ultra-high-speed and high-precision CNC machine tools, It has broad application prospects in aerospace, wind power generation, biomedicine, flywheel systems, and other industrial fields. Background technique [0002] Magnetic bearing is a new type of high-performance bearing that uses magnetic field force to suspend the rotor in space and realizes no mechanical contact between the rotor and the stator. It has no friction, no wear, no lubrication and sealing, high speed, high precision and long life. And a series of excellent quality, fundamentally changed the traditional support form, when the motor spindle speed supported by mechanical bearings is too high, due...

AI Technical Summary

Problems solved by technology

At present, most magnetic bearings adopt a four-pole or eight-pole structure. The drive circuit of this structure is large in size, complex in control, and high in cost.

Therefore, these magnetic bearing structures limit their practical application range in engineering

[0004] Chinese patent (CN200810234272.2) discloses a high-speed electric spindle system supported by an AC magnetic bearing. The AC magnetic bearing is driven by a three-phase power inverter. The three-phase inverter has low power consumption, mature technology, and low cost, so it can The development cycle and project cost are greatly reduced, but the motorized spindle uses a magnetic bearing with a radial structure of three poles. Due to the asymmetry of the structure of the three-pole magnetic bearing, the nonlinear and coupling relationship between the two degrees of freedom is very Strong, not conducive to precise control

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