| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric fuel pump having reduced noises without causing the concentration of peak sound pressure on a specified frequency and improved discharge efficiency. SOLUTION: The electric fuel pump has an impeller 30 formed in a disc shape consisting of a number of blade pieces 31 provided on the outer periphery edge and protruded in the circumferential direction, partition walls 32 extending between the blade pieces 31 and blade grooves 33 formed by the partition walls 32 and the blade pieces 31 provided before and behind the partition walls 32. Pitches between the adjacent blade pieces 31, 31 continuously change to form one cycle of a trigonometric function on one round of the impeller 30 in its peripheral view. COPYRIGHT: (C)2004,JPO
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