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robots:armadillo:hardware:gearratio [2012/01/11 18:50] claes created |
robots:armadillo:hardware:gearratio [2021/08/14 04:21] (current) |
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The gear ratio $R$ is inversely proportional to ratio of the number of teeth, $N_a$ and $N_b$, of the two gears. | The gear ratio $R$ is inversely proportional to ratio of the number of teeth, $N_a$ and $N_b$, of the two gears. | ||
$$R=\frac{N_b}{N_a} $$ | $$R=\frac{N_b}{N_a} $$ | ||
+ | The beltmodules uses the same concept as shown in the picture below, from [[http:// | ||
+ | {{ : | ||
+ | From this it is possible to derive the gear ratio formula for the cogs in the beltmodule. | ||
+ | $$R=\frac{N_b}{N_a}*\frac{N_d}{N_c} $$ | ||
- | | + | /* |
- | *$ N_2=22 | + | To get the correct gear-ratio the ratio between the drivewheel and the belt also needs to be taken in to account. The belt and drivewheel can be seen as 2 cirkles, the ratio is the the ratio between circumference , diameter or radius. |
- | *$ N_3=22 $ | + | $$R_{belt/ |
- | *$ N_4=22 | + | |
+ | */ | ||
+ | |||
+ | The complete solution for the gear-ratio in the beltmodule is | ||
+ | $$R=\frac{N_b}{N_a}*\frac{N_d}{N_c}$$ | ||
+ | |||
+ | ===== Gears ===== | ||
+ | The beltmodule has the following gears from the motor to the drivewheel | ||
+ | *$ N_a=22 $ | ||
+ | *$ N_b=80 $ | ||
+ | *$ N_c=17 $ | ||
+ | *$ N_d=45 $ | ||
+ | |||
+ | which gives the following ratio | ||
+ | |||
+ | $$R=\frac{N_b}{N_a}*\frac{N_d}{N_c}=\frac{80}{22}*\frac{45}{17}=\frac{3600}{374}=\frac{1800}{187}=9, | ||
+ | |||
+ | From the divewheel to the motor the ratio is | ||
+ | |||
+ | $$G=\frac{N_a}{N_b}*\frac{N_c}{N_d}=\frac{22}{80}*\frac{17}{45}=\frac{374}{3600}=\frac{187}{1800}=0, | ||
+ | |||
+ | <file matlab gearing.m> | ||
+ | close all; clear all; | ||
+ | |||
+ | %no of teeth on the cogs | ||
+ | Na=22; %Small belt cog on the motor | ||
+ | Nb=80; %large belt cog on driveshaft 1 | ||
+ | Nc=17; %small chain cog on driveshaft 1 | ||
+ | Nd=45; %large chain cog on driveshaft 2 | ||
+ | |||
+ | R = Nb/Na*Nd/Nc | ||
+ | G = Na/Nb*Nc/Nd | ||
+ | </ |