#robotics Logs

Jun 22 2020

12:49 PM kerfluffy: suppose a bearing that has axial and radial force ratings of 300N. if that bearing is to hold a 1m long shaft with a 1kg load on the end, will the ratings be exceeded?
12:54 PM kerfluffy: so that's 10Nm. but how do you compare torque to the bearing's force ratings?
01:06 PM ThomasEgi: kerfluffy, bearing radius, axial load component i guess.you probably want to have a different bearing setup than a single bearing at this point.
01:08 PM kerfluffy: ThomasEgi but what is the axial load component when a load is placed at the end of the shaft?
01:08 PM kerfluffy: if the axial force rating is 300N, won't it be enough to have just one bearing?
01:09 PM kerfluffy: and radial force rating as well
02:34 PM Tom_L: a shaft 1 meter out from the bearing is going to be just like a pry bar on the bearing. you need more support
02:35 PM Tom_L: unless of coure like everyone else nowdays you are designing for failure
04:36 PM ThomasEgi: or. unless you have a really big bearing. you could get away with a cross roller bearing. those can tollerate momentum load.. somewhat.
04:39 PM ThomasEgi: but then you can probably assume a dynamic load case and your equivalent load would be something like 2*Momentum/bearingdiameter which would get you a diameter of about 40mm (best case with no safety). and such a bearing would typically be able to handle 10 times the load your bearing has.
04:39 PM ThomasEgi: long story short. it'll most likely fail, if not immediately it will do so mid/long term. get two bearings, space them apart properly to take care of the momentum.
04:40 PM ThomasEgi: and check with the manufactory datasheet. most of them feature detailed lifetime calculations.
11:51 PM kerfluffy: but how about the bearing's rating numbers? will a 1kg load 1m out exceed 300N axial or 300N radial limits?