Research on Tightening Technique of Turbopump Shaft System Based on Elongation Method

As the key role of turbopumps in spacecraft engines becomes increasingly prominent, accurate control of their shaft system tightening force is significant to ensure the stable operation of the engines. Although the traditional torque method has been widely used in the tightening of threaded connections, the tightening force is easily affected by the quality of threads and lubrication conditions, and the accuracy and consistency are poor. This paper investigates the elongation method based on the turbopump shaft system tightening force control method. It is applied to the turbopump rotor assembly scenario for the first time. The performance of the torque and elongation methods under different thread qualities and lubrication conditions is compared through experiments. The experimental results show that the elongation method has significant advantages in improving the consistency and accuracy of the tightening force, especially under poor thread fit or different lubrication conditions.