Research on counter-roller active spinning forming process and equipment for vehicle-mounted LNG cylinders

WANG Jun; LI Fan; ZHANG Zongyuan; GUO Xiaofeng; SHEN Yuxing; HUANG Sheng; JIN Xin

doi:10.3969/j.issn.1001-196X.2025.04.008

Abstract：To address the issues of poor weld quality and complex processes in traditional roll-welding methods for manufacturing vehicle-mounted liquefied natural gas(LNG)cylinders,this study proposes a novel counter-roller active spinning forming process and designs a dedicated full-electric servo spinning equipment.Based on analysis of process requirements for cylinder thinning and dome forming of LNG tanks,key technical parameters are established,including a maximum radial force of 300 kN and processing range of 600-800 mm.The equipment employs a vertical structural layout with innovative independent radial/axial feed systems for inner and outer spinning rollers.The spindle turntable is driven by three servo motors in coordination,while the outer roller assembly features dual-cone rollers and axial screw transmission.The inner roller achieves precision feeding through worm-gear and wedge mechanisms.Finite element analysis verifies critical components:The frame demonstrates maximum equivalent stress of 64.58 MPa with 0.174 mm deformation,and its six-order modal frequencies(8.42-30.48 Hz)remain distant from the operational frequency of 1.33 Hz.The inner roller support shows maximum stress of 192.21 MPa and radial deformation of 0.31 mm,both meeting the strength requirements of 45# steel.This integrated equipment combines cylinder thinning and dome forming capabilities,achieving seamless weld-free fabrication of LNG cylinders through coordinated control between active roller rotation and workpiece revolution.The design provides an innovative solution for manufacturing new energy fuel storage and transportation equipment.