Combined piston

The utility model discloses a combined piston which comprises a first piston and a second piston. The two first pistons are mutually connected in the axial direction; an annular groove is formed in the joint of the two first pistons; the second piston is annular, a mounting groove is formed in the outer side wall of the second piston, and the sealing ring is mounted in the mounting groove; the second piston is clamped and mounted in the annular groove; the two first pistons and the second piston are combined, the second piston is clamped through the two first pistons, and the combined structure is high in strength, low in specific gravity, convenient to install and suitable for ERC series high-rotating-speed compressors; the second piston is made of steel materials and is more economical and practical, and performance requirements of aluminum materials at the two ends of the piston are reduced. 本实用新型公开了一种组合式活塞，包括两个第一活塞、第二活塞；两个第一活塞在轴向上相互连接；两个第一活塞的连接处形成有环形凹槽；第二活塞形成为环形，第二活塞的外侧壁上设置有安装槽，密封圈安装在安装槽内；第二活塞夹持安装在环形凹槽内；本