The pipe connector of the invention adopts the opening annular outer case with the structure connected by two arc-shaped case body hinges, and can be conveniently opened and closed.

A first inwardly extending annular shoulder is provided between the sealable opening and the bottom opening, defining a flow passage along a longitudinal axis of the housing.

A semi-annular bearing with an opening is used to support both ends of inside engaged gear or for fixed-axle gear box.