The utility model relates to a rotary-vane vacuum pump, which provides a columnspiral torsional spring which is used for replacing a columnspiral compressing spring.
本实用新型涉及旋片式真空泵，提供一种圆柱螺旋扭转弹簧，用它取代圆柱螺旋压缩弹簧。
2
With spiral hoops strengthen column can raise transshape capacity of vertical reinforcement and concrete when the columns are destroying.