Gear outer diameterNow I have a plastic (Sai Gang) 44 teeth gear, measuring the outer diameter is 32.5, please ask modulus and so on, what is the parameter?I say that the measurement of the outer diameter is the caliper to the top of the tooth circle diameter, this number is about inaccurate, as close as possible, the operation process is written outTry to figure out is not standard or not and this is the imperial plastic (match just shrunk 1.02) to analysis will shrink the size of the problem
Since there is a mantissa in the calculation process, the inverse calculation should be performed in accordance with the m=0.7:D=mz=0.7 * 44=30.8D top =D+2m=30.8+2 * 0.7=32.2The above calculation and actual measurement of the difference value you 0.3, which means that this is not a standard gear gear, a gear, and a positive displacement gear modification coefficient is +0.15 (with the difference divided by 2).Injection molding is a shrinkage problem, and the size of the shrinkage requires experimentation.In this case, the actual gear is slightly larger than the standard gear to be calculated. It should not be a shrinkage problem, but rather a gear with a center pitch.I hope the above can help you
Upper middle:D - diameter of pitch circleM - modulusZ - number of teethD top diameter of addendum circleAccording to the formula, as follows:D top =D+2mD top =mz+2mD top =m (z+2)D top =m (44+2)D top =46mM=D top /46=32.5/46=0.70652......According to the standard in the manual of mechanical design, the standard modulus should be chosen as:M=0.7
Stj368143321 hello!Answer your question:This gear of yours is a small modular gear, which is calculated according to the basic formula of the gearBasic formula:D=mzD top =D+2m
