Design of small direct drive axial permanent magnet motor
This paper designs an axial permanent magnet cursor motor topology with low speed and large torque characteristics for the lens-driven small direct drive system. The structure uses annular permanent magnets and concentrated windings to adapt to the limited motor installation space and torque output. Claim. In the design, the magnetic circuit analytical model and finite element analysis method of permanent magnet motor are used to evaluate and compare the main steady-state characteristics of the motor, and verify the operating characteristics of the proposed motor at 0-100 rpm low speed, which provides the basis for the design of this type of motor. experience.
1 Introduction
In the lens drive system, depending on the mounting position of the drive motor, it is generally divided into the following categories: body drive type, lens drive type, and body lens double drive type. Among them, the lens drive type (the type in which the drive motor is directly mounted in the lens) makes the system reduce the setting of the reducer and the flexible linkage mechanism, and the motor performance is generally superior to that of the body drive motor, but requires the use of a direct drive capable of achieving low speed and high torque. Motor. At present, most direct-drive applications are driven by low-speed and high-torque through a reduction gear. Although the conventional precision transmission is relatively mature, it is usually bulky, noisy, and inefficient, so there is no need for a shifting device. Low-speed, high-torque direct-drive motors are urgently needed [1]–[3]. The direct drive motor is applied to the small lens drive system, which can directly convert electromagnetic energy and mechanical energy to reduce energy loss. At the same time, the traditional electromagnetic motor can learn from the mature motor control strategy and the ultrasonic motor with the help of piezoelectric ceramics. 4] Drive comparison, to achieve precise and stable control of the motor.
Permanent magnet cursor motor is a popular axial magnetic field type permanent magnet synchronous direct drive motor. Due to its multi-pole design, it has low-speed and high-torque "magnetic gear" characteristics [5]-[6], which overcomes the traditional permanent magnet synchronization. Many shortcomings of the motor in direct drive applications have good application and research prospects. The mechanism of the cursor motor is more complicated than the traditional permanent magnet motor, but the unique design principle makes it have low speed and high torque characteristics without relying on the reduction gear, so it is widely used in the direct drive system. Although the permanent magnet vernier motor has a backward performance compared with the magnetic gear composite motor in terms of torque density, the amount of permanent magnet is reduced by nearly half, and the torque density is greatly improved compared with the conventional permanent magnet motor. At the same time, reasonable pole number design and cogging optimization can optimize the large torque characteristics of the cursor motor, and the disc axial axial gap magnetic field design of the same power level can further reduce the motor volume compared with the radial magnetic field design. , increase the torque density [7].
Therefore, based on the application of the small lens drive system, this paper proposes a design scheme using an axial permanent magnet cursor motor structure, and the motor is at a low speed through the magnetic circuit analysis method and the three-dimensional finite element simulation method. The steady-state characteristics of the area are evaluated, and the operating characteristics and optimization schemes of the low-speed and high-torque electromagnetic motors under such conditions are explored.
Please pay attention to Valve Motor
