Non-spherical orthogonal structure two-degree-of-freedom hybrid stepping motor and its method

Abstract

The invention discloses a two-degree-freedom mixed type stepping motor with a non-spherical orthogonal structure and a method thereof. The motor comprises a pedestal, and a first-degree-freedom motor installed on the pedestal. The rotating shaft of the first-degree-freedom motor is of a semi-cylindrical shape, and the external diameter of the rotating shaft is greater than the external diameter of a stator iron core of a second-degree-freedom motor. A notch is arranged on the planar side of the rotating shaft, so that the second-degree-freedom motor is integrally embedded in the notch. The rotating shaft of the second-degree-freedom motor is of a complete cylinder shape and is provided with an output shaft. The central axis of the rotating shaft of the first-degree-freedom motor is positioned on a horizontal plane and is set as an X-axis, and the central axis of the rotating shaft of the second-degree-freedom motor is vertically orthogonal to the X-axis. The central axis of the rotating shaft of the second-degree-freedom motor is set to be Y-axis, and the rotating shaft of the first-degree-freedom motor drives the second-degree-freedom motor to integrally rotate about the X-axis within a certain scope. The axis of the output shaft is vertically orthogonal to the Y-axis, thereby realizing two-degree-freedom movement of the output shaft.

Description

technical field [0001] The invention belongs to the field of motors, in particular to a non-spherical orthogonal structure two-degree-of-freedom hybrid stepping motor and a method thereof. Background technique [0002] A multi-degree-of-freedom motor refers to a motor that has two or three rotational degrees of freedom and can rotate around a fixed-point spatial axis. It has the characteristics of high mechanical integration, motor structural materials and high utilization of drive control system components. In a mechanical system with multiple degrees of freedom of motion, one multi-degree-of-freedom motor can replace two or more single-degree-of-freedom motors. The structure of the mechanical system can be greatly simplified, the volume and weight can be reduced, thereby improving the accuracy and dynamic performance of the system, and improving the performance-price ratio. Therefore, multi-degree-of-freedom motors are widely used in robots, multi-coordinate machining cen...

AI Technical Summary

Problems solved by technology

Among them, the manufacturing and processing technology of the multi-degree-of-freedom motor with the traditional spherical structure is relatively difficult, and the motor control system is too complicated. It is necessary to install a position detection device to form a closed-loop control, so as to achieve accurate positioning of the output shaft, resulting in a larger overall volume and weight of the motor. ; The manufacturing and processing technology of the two-degree-of-freedom motor based on the orthogonal structure is relatively mature, and the motor can be controlled in an open-loop manner, thereby eliminating the need for a position sensor, simplifying the control system, and reducing the overall volume and weight of the motor, but there are still A series of difficult problems, such as:

[0006] 1. figure 1 Schematic diagram of an orthogonal cylindrical structure two-degree-of-freedom motor developed for Harbin Institute of Technology. The motor is composed of a first-degree-of-freedom motor 1, a second-degree-of-freedom motor 2, an output shaft 3, and a positive base 4. Among them, the first-degree-of-freedom motor 1 works In the state of hybrid stepping motor, the step angle is small and the open-loop positioning accuracy is high. The second degree of freedom motor 2 works in the state of permanent magnet stepping motor, the step angle is large, and the open-loop positioning accuracy is low, so the two degrees of freedom The overall positioning accuracy of the motor is poor

[0007] 2. figure 2 Schematic diagram of an orthogonal structure two-degree-of-freedom hybrid stepping motor developed for Zhejiang University, image 3 Schematic diagram of the two-degree-of-freedom hybrid stepping motor developed for Shandong University, both of which are composed of the first degree of freedom motor 1, the second degree of freedom motor 2, the output shaft 3 and the positive base 4, and the first degree of freedom motor 1. The second degree of freedom motor 2 is working in the state of hybrid stepping motor, with small step angle and high open-loop positioning accuracy. Since the second degree of freedom motor 2 adopts a special non-cylindrical structure motor, it will be in the rotation process Under the influence of asymmetric electromagnetic torque and gravity, mechanical unbalanced force will be generated, which will cause motor disturbance, and may cause the motor to fail to operate normally in serious cases

[0008] 3. by figure 1 , figure 2 , image 3 It can be seen that the outer diameter of the first-degree-of-freedom motor of the traditional orthogonal structure two-degree-of-freedom motor is smaller than the inner diameter of the second-degree-of-freedom motor, that is, the first-degree-of-freedom motor (usually a complete cylindrical motor that needs to drive the second 2 degrees of freedom motor and load movement) adopts a small motor structure, while the second degree of freedom motor (a complete or part of cylindrical structure motor, which only needs to drive the load movement) that plays a secondary driving role adopts a large motor structure, and the first The increase of the volume and torque of the 1 degree of freedom motor is limited by the size of the 2nd degree of freedom motor, which has certain problems in the rationality of the motor structure design

[0009] 4. by figure 1 , figure 2 It can be seen that the space at both ends of the first degree of freedom motor and the second degree of freedom motor of the two structures of the two degrees of freedom motor is not fully utilized, which reduces the overall mechanical integration of the two degrees of freedom motor to a certain extent. , increasing the overall size of the motor

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