Amateurdesigners of vehicles, and motor agricultural machinery often have to work with what is at hand. Typically, this is the engine from a moped or motorcycle, the wheels of a Bicycle, scooter or sidecar, some factory default or self-made components and parts. When the idea to connect them all in varying designs, the inevitable question what to take counter sprocket (driving is already on the engine), how to calculate?
The simplest and most affordable is the calculation of the proportion. For example, you have the engine from a moped, the diameter of the rear wheel which D, is driven sprockets with number of teeth z And you want to use it on my car complete with wheel diameter d. Therefore, you need to find or fabricate the sprocket with number of teeth Z2 — it is easily calculated by the following formula:
Z2 = d*Z1/D.
The result may be not integer and fractional. It is clear that stars with a half or quarter of a tooth does not happen. Therefore, the value should be rounded to the nearest whole number. But remember that rounding off in a big way, you can win in power (the throttle response is better, the engine will handle the increased load), but lose top speed. With a smaller integer number of teeth will succeed Vice versa.
And again. Don’t forget when calculating to compare between a number of teeth Z1 leading (on the engine) and Z2 slave (count) of the sprockets. They don’t have to be a multiple of, that is:
Z1 ≠ Z2*P;
Z2 ≠ Z1*P,
where N is any integer. Or perhaps a periodic summation of the load chain due to the intenseness of the veins, making uneven transfer code, increases wear, increases noise.
In addition to the transfer has not worn out, do not forget this rule: any number of teeth of the sprocket should not be a multiple of the number of chain links, that is:
N≠ Z1*N ≠ Z2*P,
where N is the number of links.
Why? Let’s consider an example. For example, the asterisk in the calculations turned 25 teeth and the chain has 100 links. If the combination of any one tooth with a certain link is the largest tightness of the chain, it is the combination of our calculated data will be repeated for every four (100:25=4) of the turnover sprockets. Add to that the natural oscillations of the circuit, appearing at great speed. Thus, rapid wear of the transmission is inevitable.
By the way, to reduce the effect of resonance in the design of the rear wheels injected rubber vibration absorbers, the serviceability of which is to follow.