Optimization for Profiles of Vibration-Suppressing Oil Cavities in Electromagnetic Spherical Joint Fully Suspended Rotors

doi:10.3969/j.issn.1004-132X.2026.02.012

Abstract

Abstract:

In order to meet the specific requirements of extreme non-structural environment on variable stiffness control performance of the joints， and to address the common problems such as electromagnetic drive structure complexity， coupled magnetic field modelling difficulties， magnetic moment singularity， a two-degree-of-freedom electromagnetic flexible spherical joint， driven through the axis control of the rotating magnetic field， was proposed based on the rotational coaxial effect that the lateral coupling magnetic moment drived the axis of the permanent magnet rotor to turn to the axis of rotating magnetic fields. Since the instantaneous alternating coupling magnetic moment， which generated by the permanent magnet rotor， gave rise to a vibration problem at the output end of the joints if a rigid rolling bearing was used to support the permanent magnet rotor， this paper put forward dynamic pressure oil film vibration suppression method of a fully-suspended rotor based on multi-vee effect. The fluid dynamic characteristic equation of the oil films in sealing cavities was derived， thereafter， rotor system dynamics equation with combined variable stiffness by the electromagnetic stiffness and the stiffness of rotor dynamic pressure oil film was deduced， and the contour size and number of sealing cavities were optimized with the goal of optimal stability of the rotor systems. Simulations and experiments demonstrate that the fully suspended rotor system scheme may reduce the output end’s swing errors effectively， with a maximum reduction in vibration amplitude by 55.70%， laying a foundation for the theoretical research of anti-interference in novel electromagnetic joints.

Key words: electromagnetic spherical joint, rotating magnetic coaxial effect, critical electromagnetic frequency, profile optimization, vibration suppression

摘要：

为满足极端非结构环境对关节变刚度控制性能的特殊需求，解决球型关节普遍存在的电磁驱动结构复杂、耦合磁场建模困难、磁矩奇异性等问题，基于永磁转子轴线始终转向旋转磁场轴线的旋转定轴效应，设计了一种通过旋转磁场轴线控制驱动的两自由度电磁柔性球型关节。由于永磁体转子产生瞬时交变耦合磁矩，针对滚动轴承刚性支撑永磁转子导致的关节输出末端振动的问题，提出一种全悬浮转子多楔形效应动压油膜振动抑制方法。通过建立密封腔油膜流体动态特性方程推导了电磁与转子动压油膜复合变刚度转子系统动力学方程，以转子系统稳定性最优为目标，对密封腔廓形尺寸和数量进行优化设计。仿真和试验结果表明：全悬浮转子系统方案能够有效减小输出端摆动误差，振动幅值最大可减小55.70%，为新型电磁关节抗干扰理论研究奠定了基础。

关键词: 电磁球型关节, 旋转定轴效应, 临界电磁频率, 廓形优化, 振动抑制

CLC Number:

TP242

SUN Lifeng, ZHANG Yongshun, LU Tianyu, LIU Zhenhu, SUN Limin. Optimization for Profiles of Vibration-Suppressing Oil Cavities in Electromagnetic Spherical Joint Fully Suspended Rotors[J]. China Mechanical Engineering, 2026, 37(2): 374-382.

孙立峰, 张永顺, 鲁天宇, 刘振虎, 孙丽敏. 电磁球型关节全悬浮转子抑振油腔廓形优化[J]. 中国机械工程, 2026, 37(2): 374-382.

Figures/Tables 15

Fig.1 Structure of electromagnetic spherical joint

Fig.2 Permanent magnet rotor support method

Fig.3 rotor system coordinate system

Fig.4 Plan view of the seal chamber

Fig.5 Force diagram of the joint

Fig.6 Stiffness relationship analysis

Fig.7 Comparison of equivalent stiffness of optimised oil cavity profiles

Fig.8 Effect of number of endface profiles on rotor axial eccentricity

Fig.9 Simulation of critical electromagnetic frequency of joint

Fig.10 Electromagnetic spherical joint experiment platform

Fig.11 Experimental model of rotor system

Fig.12 Experimental deflection angle

Tab.1 Maximum amplitude of vibration for the two support methods

偏转角度/（°）	多楔形油腔支撑/（°）	轴承支撑/（°）	振动抑制率/%
0	1.14	1.52	25.00
6	1.28	1.84	30.44
12	1.33	1.91	30.36
18	1.36	3.07	55.70

Fig.13 Vibration comparison of deflection experiment

Fig.14 Critical electromagnetic frequency verification

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