Pipe expander

A tube expander, comprising:

• a driver;
• a chuck, wherein the chuck comprises a plurality of jaws which are movable between a contracted state and an expanded state, in the contracted state, the plurality of jaws abut against one another and jointly define a tapered chuck end, and in the expanded state, the plurality of jaws expand radially outward;
• and
• a transmission assembly, wherein the transmission assembly is configured to transmit power of the driver to the chuck, so as to drive the plurality of jaws to expand and the chuck to rotate around an axis of the tube expander,
• wherein the transmission assembly comprises:
• a tapered needle comprising a conical section and a cylindrical section, wherein the cylindrical section is provided with a guiding groove comprising an inclined section extending obliquely relative to the axis, and the driver is configured to drive the tapered needle to advance along the axis towards the chuck, allowing the conical section to push the plurality of jaws to transition from the contracted state to the expanded state;
• a return mechanism, wherein the return mechanism is configured to retract the tapered needle away from the chuck along the axis, so that the plurality of jaws are switched from the expanded state to the contracted state;
• a pin and a pin mounting seat, wherein the pin is disposed in the pin mounting seat and at least a part of the pin is received in the guiding groove, and the pin is capable of cooperating with the inclined section of the guiding groove, enabling the tapered needle to rotate around the axis while moving along the axis;
• and
• a one-way torque transmission mechanism, wherein the one-way torque transmission mechanism is configured to transmit torque generated by rotation of the tapered needle in one direction to the chuck, and not to transmit torque generated by rotation of the tapered needle in an opposite direction to the chuck.