|
Re: Bevel/Miter Gear Mounting Distances
Are thrust bearings required behind the bevel gears? No. Some teams have not used them and it will work. Our justification for them is long term protection from wear. Our robots rack up hours and hours of run time from many events, driver practice and demos. They are cheap failure protection. Also note that there are some very large dynamic loads. This years game was very tame for drive trains. And then there was 2014. We have never had any failures in this part of the module. We will always use thrust bearings. We do not use radial ball bearings on the vertical. We use needle bearings and the thrust bearings. The drive shaft is 4140 steel. We have contemplated going with a 7075 drive shaft with radial ball bearings. Have always questioned the durability of a 7075 shaft in this application. We try to maintain tight tolerances on the bevel gears. That said we have 1 module that is about .023" off on the vertical bevel. It's been bouncing around since 2013 and still works. Just beginning to have very slight wear. No matter how a team chooses to do the bevel gear and bearings the 1 most important thing for teams to do is design the lower module so that it does not "rack". Racking will lead to wear and failure.
|