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US 2003/0118439 A1Published application
Fuel pump
AssigneeAisan Kogyo Kabushiki Kaisha
InventorsTakayuki Usui, Kenzo Nagasaka, Koichi Iwata
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Abstract
A fuel pump capable of using the pump efficiency most efficiently without reducing the useful service life is provided. A relatively large clearance allowing for the expected amount of wear is ensured in a region where the flow passage groove pressure is low. In a region where the flow passage groove pressure is high, it is unnecessary to allow for the wear. Therefore, the clearance is set relatively small.
Claims7
A fuel pump comprising:
- an impeller having an approximately disk-shaped configuration with a plurality of blade grooves formed serially in a region extending along outer peripheries of obverse and reverse sides of the impeller, wherein an outer peripheral surface of said impeller is a circumferential surface, said impeller being rotated by driving means;
- and
- a pump casing having a circumferentially extending recess for forming a circumferentially extending flow passage groove between the same and the blade grooves of said impeller, said pump casing further having a suction opening communicating with an upstream end of said recess and a discharge opening communicating with a downstream end of said recess, said pump casing further having a circumferential wall forming an inner peripheral surface facing the outer peripheral surface of said impeller;
- wherein a clearance between the outer peripheral surface of said impeller and the inner peripheral surface of said pump casing is relatively small in a region where a flow passage groove pressure is high, and said clearance is relatively large in a region where the flow passage groove pressure is low.
1 more element
Dependencies are inferred from the claim text.