Research on a novel high stiffness axial passive magnetic bearing for DGMSCMG

• A novel high stiffness axial passive magnetic bearing for DGMSCMG.
• The proposed APMB is composed of segmented permanent magnets and magnetic rings.
• The APMB is analyzed by EMCM and infinitesimal method based on the end magnetic flux.
• The axial displacement stiffness measurement method of the APMB is proposed.
• The DGMSCMG is manufactured and proved the correctness of theoretical analysis.

To increase the displacement stiffness and decrease power loss of double gimbals magnetically suspended control momentum gyro (DGMSCMG), this paper researches a new structure of axial passive magnetic bearing (APMB). Different from the existing APMB, the proposed APMB is composed of segmented permanent magnets and magnetic rings. The displacement stiffness and angular stiffness expressions are derived by equivalent magnetic circuit method and infinitesimal method based on the end magnetic flux. The relationships are analyzed between stiffness and structure parameters such as length of air gap, length of permanent magnet, height of permanent magnet and end length of magnetic ring. Besides, the axial displacement stiffness measurement method of the APMB is proposed, and it verified the correctness of proposed theoretical method. The DGMSCMG prototype is manufactured and the slow-down characteristic experiment is carried out, and the experimental result reflects the low power loss feature of the APMB.