页岩气旋转式井壁取心液压马达的设计与研究

Design and research of the shale-gas rotary shaft wall coring hydraulic motor

液压马达作为页岩气旋转式井壁取心机器人钻头的直接驱动装置,其性能的优劣决定了整个取心机器人能否正常完成井下取心任务。根据川渝地区页岩气长水平段取心的高温、高压、高腐蚀等工作特点,对传统三齿轮液压马达进行适应性改进设计。根据齿轮马达的工作原理,分析了取心液压马达的排量、输出转矩、径向力等工作性能。分析表明,取心马达分别有两对高压腔和低压腔,实现了转矩的叠加,在相同体积情况下,其排量、输出转矩大,有利于在页岩气长水平段井下的狭小空间工作。

The hydraulic motor is used as the direct drive device of the robot bit’s shale-gas rotary shaft wall coring.Its performance determines whether the entire coring robot can normally complete the underground coring task.According to the hightemperature,high-pressure,high-corrosion and other working characteristics of the long horizontal sections of shale gas in the Sichuan-Chongqing area,the three-geared hydraulic motor is subject to the adaptive design.Based on the working principle of the gear motor,such factors as the hydraulic motor’s displacement,output torque,and radial force are explored.The results show that the coring motor has two pairs of high-pressure cavity and low-pressure cavity respectively,therefore achieving the superposition of torque.With the same volume,the coring motor’s displacement and output torque are large,which is beneficial to those tasks in the narrow space in the long horizontal sections of shale gas.