Encapsulation of back pressure formula machine is put

The utility model belongs to the mechanical seal device, concretely relates to encapsulation of back pressure formula machine is put, quick -witted big envelope overlaps in the axis of rotation, and the quick -witted big envelope outside is provided with the location boss, and the movable sealing ring cover is on quick -witted big envelope and on the location boss of joint on quick -witted big envelope, and quiet seal annular sleeved meets outside quick -witted big envelope and on one side of movable sealing ring, and the seal end plate cup joints on the static seal ring, sealed lid activity is cup jointed on the seal end plate, and locating pin and quiet ring gland connection are passed through to the one end of sealed lid, the sealed lid is provided with the spring between intermediate position and the seal end plate intermediate position, the one end and the seal box of spring are connected, and the other end and the quiet ring gland connection of spring, sealing box body cup jointand cover sealed, simple