Study on heat transfer characteristics and thermal error suppression method of cylindrical giant magnetostrictive actuator for ball screw preload

Abstract

Based on the structure analysis and the working principle of cylindrical giant magnetostricve actuator (CGMA) for ball screw preload, a thermal error suppression method using oil cooling system to control the temperature is proposed. Firstly, the heat transfer model and thermal circuit model of CGMA are established; next, the steady-state temperature model and the thermal expansion displacement model of cylindrical giant magnetostrictive material (CGMM) are obtained according to the heat-transfer rules and loop analysis method in circuit analysis; finally, the design parameters of the oil-cooling temperature control system are determined by combining thermal circuit model analysis with finite element simulation analysis. Such optimization method saves a lot of computation and provides a simple way for the design of oil cooling structure. In addition, a test platform for the CGMA is established. The experimental results indicate that the measured temperatures are in good agreement with the simulation results under forced oil cooling, and the relative error is less than 5%, which proves the rationality of the temperature control system. Moreover, the output accuracy and stability of the CGMA is significantly improved with proposed oil cooling method, which further confirms the thermal error suppression method is effective. As a result, this study provides a basis for the application of CGMA in the precise adjustment of double-nut ball screw preload.

Preload degradation mechanism of double-nut ball screws revealed by an innovative wear distribution model

“…The motions between the ball/screw-raceway and the ball/nut-raceway are not pure rolling simultaneously. 24 Besides, v H AS and v H BS are the relative sliding velocities of the point A and the point B, respectively, as presented in equations ( 4) and (5). As the friction coefficient of the nut raceway is larger than that of the screw raceway, the motions of the point A on the screw raceway and the point B on the nut raceway are rolling-sliding mixed and pure rolling, respectively.…”

“…It is therefore highly essential to study raceway wear since the raceway wear is a complex process using kinematics, force balance, and contact mechanics. 3–5…”

“…It is therefore highly essential to study raceway wear since the raceway wear is a complex process using kinematics, force balance, and contact mechanics. [3][4][5] In terms of the kinematics and force balance analyses of ball screws, balls can generate inertial force regardless of whether the screw rotates at a constant or accelerated speed. To reduce the difficulty of mechanical analysis, a number of scholars neglected the effects of inertial force in a low-speed ball screw.…”

Numerical Evaluation and Experimental Test on a New Giant Magnetostrictive Transducer with Low Heat Loss Design

“…Substituting Equations ( 13) and ( 14) into Equation (15), the relationship between the electromagnetic refraction ratio and the incident medium parameters can be derived as,…”

“…Xavier proposes that utilizing specific permanent magnets can achieve magnetic deviation and reduce the thermal effect in the end [14]. A thermal error suppression method using an oil cooling system to control the temperature is proposed by Ju and the research could provide a basis for the application of cylindrical GMT in the precise adjustment of double-nut ball screw preload [15]. Similarly, other researchers put forward their own views on designing a GMT with different aims, such as low eddy current loss characteristics, temperature compensation design, the effect of core geometry on the performance, etc.…”