Abstract
The synergistic control of resistance reduction and sealing poses challenges to enhancing the rapid dynamic response ability of servo hydraulic cylinders; the key to solving this problem is effectively controlling the sealing gap value. In this study, a micro-variation between the hydraulic cylinder and the piston based on the disadvantage of conventional seals, constant gap seals, and lip gap seals was constructed; MSMA assist support blocks were designed on the piston to form a gap seal strip; then, the sealing gap value could be changed by controlling the magnetic field intensity. Simultaneously, the effects of magnetic field strength, parts-manufacturing precision, temperature, and hysteresis on the micro-variation in the MSMA were analyzed, and effective solutions were proposed. Finally, experiments on the magnetic field, temperature, and hysteresis were conducted by the measurement system. The results showed that the variable value of the sealing gap with the MSMA is feasible under ideal conditions, and can effectively change the amount of MSMA expansion by controlling the magnetic field strength, temperature, preload, etc., and then change the amount of the sealing gap of the hydraulic cylinder. This is the key to achieving friction and sealing control, which plays a crucial and active role in improving the efficiency of hydraulic systems. However, the impact of hysteresis effects cannot be ignored, which will be the main problem to be solved in the future.
Highlights
Hydraulic transmission uses liquid as the working medium to transmit motion, and has become one of the forms of transmission in the field of mechanical engineering
A plurality of annular grooves is designed on the outer surface thereof according to the length of the piston, and several Magnetic shape memory alloy (MSMA) auxiliary support blocks are continuously arranged in the annular groove, thereby constructing a few gap seal rings
By analyzing the working principle of the MSMA support block and the work characteristics, the system can be simplified to the equivalent mechanical model shown in Figure 5, where m is the total weight of the MSMA support block and hydraulic oil, F and x are the output force and displacement of MSMA, respectively; K is the equivalent spring stiffness of the recovered magnetic field; and C represents the viscous resistance of the hydraulic oil
Summary
Hydraulic transmission uses liquid as the working medium to transmit motion, and has become one of the forms of transmission in the field of mechanical engineering. Magnetic shape memory alloy (MSMA) is a new and promising type of functional material, and has attracted considerable attention from researchers because of its large recoverable strain (micro deformation), fast response speed, and high-cycle fatigue properties [5,6]. We propose using the electromagnetic drive expansion effect of MSMA to control the sealing gap of the hydraulic cylinder and to achieve the purpose of reducing internal leakage. The MSMA essentially uses a magnetic field to control the reorientation behavior of the twins [17] A plurality of annular grooves is designed on the outer surface thereof according to the length of the piston, and several MSMA auxiliary support blocks are continuously arranged in the annular groove, thereby constructing a few gap seal rings
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
