Mechanical stroke limiting device mounted at valve rod of electric valve

The invention discloses a stroke mechanical limiting device installed at a valve rod of an electrically operated valve, which comprises a valve body and a limiting unit, the limiting unit is arranged in the valve body and is used for preventing a motor from rotating after a disconnecting link reaches a limit position, so that the phenomenon that the motor is burnt out is avoided, the valve body comprises the valve rod, a first driving piece and the disconnecting link, the valve rod is a threaded rod, and the first driving piece is arranged on the valve rod. And the first driving piece drives the valve rod to rotate. The limiting unit comprises a cylinder matched with the valve rod in a threaded mode, a movable clamping block matched with the cylinder in a rotating mode, a first sliding block and a second sliding block, wherein the first sliding block and the second sliding block are arranged on the movable clamping block and matched with the movable clamping block in a sliding mode. According to the device, t