Nakamura T, Hayashi K, Hirano K, Matsumoto T
Department of Electrical and Information Engineering, Faculty of Engineering, Yamagata University, Yonezawa, Japan.
Biomed Mater Eng. 1994;4(1):27-36.
Limiting factors of the system efficiency of an electric-motor-driven ventricular assist device (VAD) consisting of a brushless dc motor and a ball screw in the actuator were analyzed from the balance of force and torque in the pump and actuator. The results suggested that several mechanical components in the actuator should be improved to increase the efficiency. According to the suggestion, rotor material was changed from stainless steel to a lighter engineering plastics; smaller ball bearings were used to reduce rotor inertia; the ball screw was changed from rolled- to ground-execution type; the friction loss in the anti-rotation column inside the ball screw shaft was reduced by changing sliding mechanism to rolling one. These improvements elevated the total system efficiency from 11% to 15%. The new system cleared durability testing of longer than 900 h. More elaborate assembly of the mechanical components of the actuator would increase the efficiency.
从泵和执行机构中的力与扭矩平衡角度，分析了由无刷直流电机和执行机构中的滚珠丝杠组成的电动心室辅助装置（VAD）系统效率的限制因素。结果表明，应改进执行机构中的几个机械部件以提高效率。根据该建议，将转子材料从不锈钢改为更轻的工程塑料；使用更小的滚珠轴承以降低转子惯性；将滚珠丝杠从轧制型改为研磨型；通过将滚珠丝杠轴内防旋转柱的滑动机构改为滚动机构，降低了摩擦损失。这些改进使系统总效率从11%提高到了15%。新系统通过了超过900小时的耐久性测试。对执行机构的机械部件进行更精细的组装将提高效率。
