Opening and closing friction-free ball valve

The invention relates to the field of ball valves, in particular to an opening and closing friction-free ball valve which comprises a valve body, a rotating mechanism, a ball core and linkage mechanisms in one-to-one correspondence with seat rings, and a valve seat is mounted in the valve body; the rotating mechanism comprises a support rotationally supported on the valve body and a rotating shaft connected with the support to drive the support to rotate. The support is sleeved with the ball core, the ball core is located in the valve body, and a seat ring used for being matched with the valve seat to achieve sealing is installed on the ball core. The linkage mechanism is arranged among the valve body, the support and the seat ring and used for enabling the seat ring to retract towards the ball core side and then enabling the ball core to rotate along with the support when the support rotates so that the ball valve can be closed from the full-open state or opened from the full-closed state. And when the ball