Electric vehicle gear ratio help ??

Question

An electric vehicle used in a fairground ride uses an electric motor that should run at a constant speed of 1000 r.p.m. The diameter of the driven wheel is 20cm. if you are using a chain and sprocket to deliver the power from the motor to the wheel, what gear ratio is required if the vehicle has to be designed to move at a constant speed of 10km/hr? the range of drive sprockets available is from 10 teeth to 50 teeth. you must get as close to the required drive speed as possible?

i dont even know where to start when answering this question !! PLEASE HELP !!

Answer 1

YOu can use 38 and 10 too, hope this helps.

Answer 2

Not enough information.

You know that you need to get the driven wheel to go 265 r.p.m.   (10,000 m/hr / ((0.2  x π m/rev) x 60 min/hr))

Without a relationship between teeth and diameter of the sprocket (or of the driven wheel), you cannot set up the relationships required to solve the problem.

Answer 3

The wheel has a diameter of 20 cm which is a circumference of πd or 62.83 cm or 0.6283 m

The vehicle is moving at 10 km/hr which is 10000 m/hr or 166.7 m/min

In order for the wheel to move 166.7 m, at a rate of 1 rev/0.6283, you get 265.27 rev, which means the wheel has to rotate 265.27 times per minute.

The electric motor is rotating at 1000 rev/min, so the gear ratio has to be

1000/265.27 or 3.770 to 1. A step down by that ration, with big gear on the rear axle.

Now we have to pick ratios to get that.

50 and 13 is close, at 3.85

49 and 13 is ever closer at 3.770

I'd go with the 49 and 13

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