Thereby measures for improvement are put forward : ( 1 ) adopting a small wheel to replace the steel ball of the ball type unit to ensure more reliable motion of the creeping device ; ( 2 ) applying expansible metallic ring replacing the step - by - step teeth on tooth type unit ; ( 3 ) fixing a sensor in the reversing device for obtaining the information of motion and wear of the creeping device 为此，提出改进措施： 1 .对球型步进式清蜡器采用带穿轴的小轮代替钢球，可使爬行器运动更可靠； 2 .对齿型步进式清蜡器，采用可胀紧金属环代替步进齿，金属环依靠抽油机的冲程力胀大后使爬行器固定，反冲程力使金属环缩小； 3 .将传感器装在换向器内，根据信号的时间间隔判断爬行器的运行速度及磨损等情况。
