| 摘要 |
PURPOSE:To attempt improvement of precision of inner and outer cylindrical parts of a synthetic resin pulley and improvement of strength of the whole pulley. CONSTITUTION:A synthetic resin part main body 2 formed on the periphery of a rolling bearing 1 is composed of an inside diameter cylindrical part 3, outside diameter cylindrical part 4, a disc part and ribs 6 radially provided on the disc part. Gates 7, 8 are alternately provided in the position facing the parts between the inner ends and between the outer ends of the mutually adjacent ribs 6 of the inside diameter cylindrical part 3 and the outside diameter cylindrical part 4. In molding of synthetic resin pulley, melt resin to be pressed in and filled in from respective gates 7, 8 are joined with each other in a cavity for the inner and outer cylindrical parts in the high temperature state, so as to attempt improvement of precision of the inner and outer cylindrical parts. |
