The Analysis Of Motorcycle Gear Tooth Broken
There are many kinds of motorcycle gear, such as master and driving gear, fiddle with gear, start gear, rear driving gear, balancing gear, timing gear, tachometer gear and fuel pump gear. Here is some analysis roughly some common gear damage, next gear tooth viewpoint wear, gear fatigue and gear tooth broken.
We have discussed very nearly the tooth face wear of motorcycle gear and gear fatigue in last two articles.
Here is the analysis upon gear tooth broken.
- Gear fracture
What is worst, one or several teeth broke from the gear.It generally starts from the root of break until the broken teeth.
It happens mainly because the bending put the accent on on the tooth exceeds the bending fatigue limit. There are two kinds of fracture, rude rupture due to the short-time overload and fatigue fracture caused by repeated bending.
The specific reasons are:
- Defect material. The nonmetal impurity will degrade the bending fatigue strength.
- Defect forging parts. Micro cracks happened as soon as quenching caused by internal defects, even worse, there may appear gear splitting. Banded structure may easily cause terrific polluted crystal.
- The density of gear powder is low or uneven, which will greatly edit the bending fatigue strength.
- Surface decarburization during heat treatment. Decarburization on the surface will reduce regulate fatigue strength. Especially those motorcycle gear in imitation of tall hardness, the correct fatigue limit will be lowered at half or more.
- The transition curve ofmotorcycle garnishes aren’t within acceptable limits or rounded corners is too small, which will consequences in put the accent on concentrated upon gear tooth.
- There is difficult impurity inside the mesh of motorcycle gear.
Resolution:
- Control steel quality, especially condense the non-metallic impurities.
- Ensure the tone of forging and stamping, especially internal defects and banded structure.
- Ensure the environment of heat treatment, especially prevent surface decarbonization and direct the microstructure.
- Enpower the shot peening process. It can tally the bending fatigue strength.
- Optimize parameters of gear tooth and growth the fillet radius.
- Guarantee the sealing ofcheap brakes in view of that as to avoid hard impurities.
Example:
- Riding a motorcycle after 7000 km, bearing in mind started it, there is shortly a loud unquestionable and next the hermetic is carry upon there, more obviously as soon as idling. open the gear box, and next found a primary driven gear tooth broken.
- Check the appearance, therectifier regulator is stamping formed. There is no difficult impurities inside the gear box except the broken tooth. Heat treatment environment is fine, size and thickness is qualified, but fillet radius is a little small, lonely R0.1 to 0.2 even if the tolerable should be R0.5. Besides, the tooth density is uneven, the thickest narrowing is 6.8 g/cm3 even if the thinest dwindling is on your own 6.4 g/cm3 and the damage teeth is just close the thinest point. In a word, the general thickness should be more than 6.8 g/cm3.
- Primary driven gear will mesh taking into account the primary driving gear upon the crankshaft and there will be a categorically large impact force like starting. The impact resistant finishing is unquestionably needy if the density is low or uneven, which will next cause the gear tooth brake, besides, if the fillet radius is small, it will with cause the damage of gear tooth broken.
In conclusion, there are alternative kinds of motorcycle gear damage faults as skillfully as its reasons, you can detect and test your motorcycle gear in the same way as the above points. hope these will back up you know more virtually your motorcycle gear.
Thanks for your get older and attention.
