A built-in permanent magnet synchronous motor for high-speed electric spindle

Abstract

The invention relates to a built-in permanent magnet synchronous motor used for a high-speed electric spindle. The built-in permanent magnet synchronous motor comprises a stator iron core, a rotor iron core, a rotation shaft, magnetic steel and stator three-phase symmetrical windings. The built-in permanent magnet synchronous motor is characterized in that the magnetic steel is V-shaped magnetic steel which is evenly inlaid in the circumferential direction and radially magnetized; the V-shaped magnetic steel comprises a plurality of permanent magnets, a plurality of magnetic insulation bridges and a plurality of magnetic bridges; the permanent magnets are arranged on the two sides of the V-shaped magnetic steel, the magnetic bridges are arranged between the adjacent permanent magnets and the magnetic insulation bridges are arranged at the top ends of the V-shaped edges on the two sides and the bottom ends of the V-shaped magnetic steel. The built-in permanent magnet synchronous motor used for the high-speed electric spindle has the advantages that the motor has the high-torque running performance achieved during low-speed running, and has a wide weak magnetic speed raising range at the constant power section above base speed; during constant-power high-speed running, the leakage flux of the permanent magnets is high and the weak magnetic speed raising capacity is high; during non-load running, the leakage flux of the motor is low and the output torque is high; the segmented unequal-thickness magnetic steel enables gap flux densities of the motor to be distributed similar to a sine, therefore, the torque pulsation is low, the control precision is high and the permanent magnets of the motor are not prone to excitation loss.

Description

Technical field [0001] The invention relates to a built-in permanent magnet synchronous motor for a high-speed electric spindle, in particular to a permanent magnet synchronous motor with high rotation speed, wide speed regulation range and high control accuracy. Background technique [0002] At present, domestic high-end CNC machine tools mainly use permanent magnet synchronous electric spindles. However, its core component-the permanent magnet synchronous motor is excited by permanent magnets. Its magnetic field is relatively constant and the excitation intensity is difficult to adjust. In the constant power operation area above the base speed of the permanent magnet synchronous motor, as the motor speed increases, the motor back EMF rises accordingly. Therefore, the upper limit of the power supply voltage and the saturation of the current controller limit its operating range, making it very It is difficult to operate in a higher speed range above the base speed. Therefore, t...

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Problems solved by technology

[0004] In order to avoid the deficiencies of the existing technology, the present invention proposes a built-in permanent magnet synchronous motor for high-speed electric spindles, which solves the problem of difficulty in increasing the speed of electric spindles with weak magnetic fields in domestic high-end CNC machine tools. Torque running performance, and in the constant power section above the base speed, it has a wide field-weakening speed-up range and high control accuracy

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