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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 | ||
| + | </ | ||