FIXING MECHANISM FOR GEAR, FLANGE, AND THE LIKE

PURPOSE: To facilitate alignment and prevent the shape of each member from being changed irregularly by piercing an outer member from the outside of a fixed member to screw the outer member with the threaded hole of a fixing member, and making the fixing member movable in an insert part by rotation. CONSTITUTION: A fixing member 3 is inserted in the insert part 10 of a gear 6 in such a relational position that the recessed part 7 of the insert part 10 and the protruding part 5 of the fixing member 3 are engaged with each other. A screw rod 9 is inserted from a hole formed at the bottom part of the insert part 10, and the tip thread part of the screw rod 9 is screwed with the threaded hole 4 of the fixing member 3. The integrated body of the fixing member 3 and the gear 6 including the insert part 10 is inserted in the end part opening part of a pipe 1 in the state of the protruding part 8 of the insert part 10 being engaged with a recessed part 2 formed on the inner surface of the pipe 1. When the screw rod 9 is further rotated, the fixing member 3 advances onto the small diameter part, side in the insert part 10 so as to open a peripheral wall part, formed at an annular rib forming the insert part 10, outward. The wall part is thereby brought into pressure contact with the inner surface of the pipe 1 to fix the gear 6 firmly to the pipe 1.