Bearing Types and their application
All bearings and bushings have the same basic function which is to reduce the rolling resistance of an assembly to minimize power losses. However, there are a few basic scenarios where one has an advantage over the other.
Bushings
Let’s start with bushings which are usually porous brass oil impregnated sleeves which a shaft rotates within. These typically have a shorter lifespan than regular bearings and can be used in lower speed scenarios or submariner applications where the vehicle will be spending a lot of its time in contact with water or even underwater.
Open bearings
Then come open bearings which can primarily be used inside sealed components such as servos or internal gearboxes. These types of bearings have no protection to dirt ingress and have the least amount of rolling resistance hence can be used for precision high speed applications.
Sealed and hybrid bearings
Lastly there are sealed bearings which have contact rubber seals which have a lip that rides on the inner and outer race of the bearing, in turn this creates maximum protection for the bearing, however since the races contact the seal, the bearing has some resistance to rotate. The best of all worlds would be a hybrid bearing, which has a rubber seal outside, towards the elements and a metal shield on the inside for higher redundance and lower seal induced friction.
Maintaining the bearings can include simply spraying wd-40 on the bearing or even going as far as opening the bearings with a dedicated seal pick and using a solvent to clean the bearing and repacking it with grease for significantly longer life.
