Self-centering coupling

The utility model provides a self-centering coupler which comprises a first clamping jaw, a second clamping jaw and a third clamping jaw. The second clamping jaw is provided with a second clamping face, and the first clamping face and the second clamping face define a containing opening; the actuating mechanism comprises a rotating element and a driving device, and the driving device drives the rotating element to rotate around a rotating axis; wherein the rotating element has a first actuation structure acting on the first jaw and a second actuation structure acting on the second jaw, during the rotating movement, the first actuating structure and the second actuating structure drive the first clamping face and the second clamping face to move towards each other by the same distance in the clamping direction perpendicular to the rotating axis. According to the self-centering coupler, the precise self-centering effect can be achieved independent of the size of the valve rod. 本实用新型提供一种自对中联轴器，其包括：第一卡爪，其具有第一夹持面；