| 摘要 |
PROBLEM TO BE SOLVED: To provide a throttle body 1 capable of keeping the smooth rotation of a driven gear 73 even though the driven gear 73 is worn out, by forming a space capable of allowing a foreign matter to stay there, besides an ordinary clearance formed on a fitting part of the driven gear 73 and a fixed shaft 11. SOLUTION: A spiral groove 73d is formed on an inner peripheral face of a central hole 73c of the driven gear 73 as the space for allowing the foreign matter generated on the fitting part such as the worn powder of the driven gear 73 and a foreign matter intruded in the fitting part from the external to stay there, at the fitting part of the driven gear 73 and the fixed shaft 11. Whereby the foreign matter can be prevented from staying in a contact part of the inner peripheral face of the central hole 73c and the fixed shaft 11 by allowing the foreign matter to stay in the groove 73d in a case when the worn powder is generated by the abrasion of the inner peripheral face of the driven gear 73 during the operation of the throttle body 1, or in a case when the fine foreign matter is intruded into the fitting part of the driven gear 73 and the fixed shaft 11 from the external, and the smooth rotation of the driven gear 73 can be continuously secured. COPYRIGHT: (C)2003,JPO
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