Throttle apparatus having axial displacement restricting structure

A throttle apparatus for an internal combustion engine, the throttle apparatus comprising:

• a throttle body that includes a cylindrical bore wall part defining an intake air passage, the bore wall part including,
• a first bearing supporting portion that is arranged on a first end side of the bore wall part in a radial direction of the bore wall part which is substantially perpendicular to a central axis of the cylindrical bore wall part, and
• a second bearing supporting portion that is arranged on a second end side of the bore wall part in the radial direction of the bore wall part,
• a first beating that is supported by the first bearing supporting portion, the first bearing defining a first sliding hole;
• a second bearing that is supported by the second bearing supporting portion, the second bearing defining a second sliding hole;
• a throttle shaft that is supported by the first sliding hole of the first bearing on an axially first end side of the throttle shaft slidably in a rotating direction, and is supported by the second sliding hole of the second bearing on an axially second end side of the throttle shaft slidably in the rotating direction;
• and
• a throttle valve that is supported by the throttle shaft so that the throttle valve integrally rotates with the throttle shaft to control an amount of intake air flowing into the internal combustion engine,
• wherein the throttle body is integrally molded of a resinous material,
• the first bearing has a first thrust restricting means that is integrally formed with the first bearing,
• the first thrust restricting means is formed of a same material as a material of the first bearing,
• the second bearing has a second thrust restricting means that is integrally formed with the second bearing,
• the first thrust restricting means is formed of a same material as a material of the second bearing, and
• the throttle shaft is at least partially inserted between the first thrust restricting means and the second thrust restricting means from both axially end sides of the throttle shaft to restrict the throttle shaft from moving axially with respect to the first bearing supporting portion and the second bearing supporting portion,
• wherein the throttle shaft includes a valve holding portion that is integrally formed with the throttle shaft to steadily hold the throttle valve in the intake air passage,
• the throttle shaft includes a first sliding portion that is integrally formed with the throttle shaft on the axially first end side axially outwardly with respect to the valve holding portion,
• the first sliding portion slides inside of the first sliding hole of the first bearing in the rotation direction of the throttle shaft so that the first sliding portion is rotatably supported by the first bearing supporting portion via the first bearing,
• the throttle shaft includes a second sliding portion that is integrally formed with the throttle shaft on the axially second end side axially outwardly with respect to the valve holding portion, and
• the second sliding portion slides inside of the second sliding hole of the second bearing in the rotation direction of the throttle shaft so that the second sliding portion is rotatably supported by the second bearing supporting portion via the second bearing.