想問問冇刷有感馬達t數和扭力問題

再請教ryancmlam師兄:
小弟想透過測試車速以配搭出最接近 摩打最高理論轉速的齒比
設小弟有大,小pully(前 ...
bravohk 發表於 2010-9-26 00:50

                               
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Linear car speed = v (m/s)
wheel radius = r (m)
wheel angular speed, w = v/r (rad/s)
Transmission geat ratio = n:1
motor angular speed, w = nv/r (rad/s)

If we convert the unit from m/s to km/h (1 m/s = 3.6 km/h) and rad/s to r.p.m (1 rad/s = 9.55 rpm) , the equation would become
motor rpm = n (3.6 v)/ (9.55 r) = 0.377n v/r

Assume speed of touring is 100 km/h with a gear ratio of 8:1 and wheel radius of 3cm, motor rpm = 0.377 x 8 x 100 / 0.03 ~ 10000 rpm.

You can observe that 10000 rpm is speed of a ~1400 kv motor and how come faster like that. Pls note it is a theoretical value only, if you take into account the loss due to transmission,  friction, road slip etc, I guess it is in the order.

As it is just my rough calculation, may not correct, would Mechanical Engineer pls comment and share you view pls.