Abstract: The performance of Positive Displacement Motor (PDM)with hollow rotor is analyzed in this paper, and the relationships between the rotary speed of rotor, torque, power, efficiency and pressure drop through motor are also discussed.It is pointed out that the soft characteristics of rotary speed and poor performance under overload are serious problems with PDM with hollow rotor.On this basis, a steady flow valve is designed and manufactured to improve the soft rotary speed.Experiments and analysis show that new rotor-hollowed PDM with steady flow valve has a better performance.The soft characteristics of rotary speed and efficiency are improved.Furthermore, a new concept of Critical Flow Rata is given to evaluate the performance of PDM with hollow rotor.

Key words: positive displacement motor, rotary speed, hydraulic power, improvement

摘要： 分析了中空螺杆钻具的外特性,探讨了中空螺杆钻具的输出转速、扭矩、功率以及效率与马达压降的关系,从而指出中空螺杆钻具存在着严重的转速软特性和抗载能力差等问题;并在此基础上研制了一种稳流阀,用于改善中空螺杆钻具转速软特性。实验和分析表明,带稳流阀的新型中空螺杆钻具显着改善常规中空螺杆钻具的转速软特性,并且效率也明显提高。文中还提出的中空螺杆钻具的临界排量的概念,可作为评价中空螺杆钻具性能的一个重要指标。

关键词: 螺杆钻具, 转速, 功率, 改进