Pulley with two flanges
In a pulley with two flanges, a pulley body and a flange body are joined by ultrasonic welding with molten resin in a resin reservoir defined by: a first space defined by a first gap and a second gap, the first gap being between an annular connecting surface connecting a first outer cylindrical surface and a second outer cylindrical surface of an inner-diameter portion of the flange body and an end face of a core metal of the pulley body, the second gap being between the second outer cylindrical surface and an inner cylindrical surface of a resin portion in the pulley body; and a second space defined by a third gap between the second outer cylindrical surface and the inner cylindrical surface of the core metal.
1 . A pulley with two flanges, the pulley comprising:
a pulley body made of a synthetic resin; and
a flange body that is made of a synthetic resin and joined to the pulley body in a concave-convex fitting state, wherein
the pulley body includes a resin portion including teeth, and a cylindrical core metal,
the resin portion includes:
a first flange that protrudes outward in a radial direction perpendicular to a rotation axis, at a first end of the resin portion in an axial direction parallel to the rotation axis; and
a fitting protrusion that has a cylindrical shape protruding in the axial direction, at a second end of the resin portion in the axial direction,
the flange body includes:
a second flange that protrudes outward in the radial direction;
a fitting recess that has a cylindrical shape depressed in the axial direction to fit to the fitting protrusion; and
an inner-diameter portion that has a cylindrical shape to be positioned inward of the fitting recess in the radial direction,
the inner-diameter portion includes:
a first outer cylindrical surface that faces an inner cylindrical surface of the resin portion, the inner cylindrical surface of the resin portion connecting to an inner cylindrical surface of the fitting protrusion; and
a second outer cylindrical surface that has a diameter reduced inward in the radial direction from an end of the first outer cylindrical surface in the axial direction, the end being close to the first end, and faces an inner cylindrical surface of the core metal or the inner cylindrical surface of the resin portion, the inner cylindrical surface of the resin portion covering a part of the core metal in the axial direction, the part including an end face close to the second end,
the pulley body and the flange body are joined by ultrasonic welding with molten resin in a resin reservoir that is defined by:
a first space defined by a first gap and a second gap, the first gap being between an annular connecting surface connecting the first outer cylindrical surface and the second outer cylindrical surface and one of the end face of the core metal and an end face of the resin portion covering the end face of the core metal, the second gap being between the second outer cylindrical surface and the inner cylindrical surface of the resin portion; and
a second space defined by a third gap between the second outer cylindrical surface and one of the inner cylindrical surface of the core metal and the inner cylindrical surface of the resin portion.