Random pitch impeller for fuel pump

摘要

A random pitch impeller for a fuel pump has number of blades. An incremental angle of the blades is set by the expression: ” �¢ ¸i = 360 N + - 1 i × Am × sin p 1 × 360 N × i × cos P 2 × 360 N × i ,
where ”¸I is the incremental angle between the blades, N is the total number of blades (N=2, 3, 5, 7, 11, 13, 17,...), Am is the distribution magnitude of the inter-blade interval (equally divided angle) (0 < Am < 360/N), i is the order of the blade (i=1, 2, 3, ... , N), and P 1 and P 2 are the factors exerting an influence on the cycle (0 < P 1 < N, and 0 ‰¤ P 2 ‰¤ N). The incremental angle has maximum and minimum values a difference of which satisfies the expression: 2° ‰¤ MAX - MIN ‰¤ 6°, where MAX is the maximum value, and MIN is the minimum value of the incremental angle.