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robots:armadillo:hardware:gearratio

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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)
Line 2: Line 2:
 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://www.dynamicscience.com.au/tester/solutions/hydraulicus/gears1compound.htm|dynamicscience.com.au]] where the gear train of four gears are connected, and the gears "B" and "C" are fixed together on the same shaft.
 +{{ :robots:armadillo:hardware:gearscompound1.gif?nolink& |}}
 +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_1=22 $ +/
-  *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 $ +$$R_{belt/drivewheel}=\frac{C_{belt}}{C_{drivewheel}}=\frac{D_{belt}}{D_{drivewheel}}=\frac{R_{belt}}{R_{drivewheel}} $$
-  *$ 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
 +
 +$$R=\frac{N_b}{N_a}*\frac{N_d}{N_c}=\frac{80}{22}*\frac{45}{17}=\frac{3600}{374}=\frac{1800}{187}=9,625 $$
 +
 +From the divewheel to the motor the ratio is
 +
 +$$G=\frac{N_a}{N_b}*\frac{N_c}{N_d}=\frac{22}{80}*\frac{17}{45}=\frac{374}{3600}=\frac{187}{1800}=0,10389$$
 +
 +<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
 +</file>
robots/armadillo/hardware/gearratio.1326304207.txt.gz · Last modified: 2021/08/14 04:20 (external edit)