upright bearings

[carmaxxx]

We have decided on using tapered roller bearings for our wheel bearings, ID 25mm, OD 52mm. What is the best way to lubricate/seal them, and how much should the centre distance between them be? I have kept approximately 20mm. Any more and the upright goes wider than 42mm.

Carrol Smith has shown a diagram of tapered bearings in use, and the centre distance was really large compared to the width of the bearings themselves.

Do teams experience any problems with lubrication and sealing of the bearings? Would a boot-type oil seal as used with a Torsen Differential work?

[Wesley]

A lot of OEM vehicles use tapered roller bearings for spindles/axles, along with a typical rubber/metal seal. Can't remember what its called.

Now whether or not that would be acceptable on an FSAE car I don't know, but it would surely seal if done properly.

[Brian Evans]

Taper rollers are pretty old school for wheel bearings these days, went out of favor for small race cars in the '70's. You seal them with lip oil seals, you lube them with wheel bearing grease. I imagine the distance between races would be dicated by the stiffness of your axle and the loads you expect to see. There are taper roller bearings available with back-to-back inner races in one piece, with the cones on either side, for effectively zero distance. There are two common ways of installing taper roller bearings - setting preload using a castle fixing nut, setting for zero pre-load and backing off to install a cotter pit through a hole in the axle, and using a precise spacer between the races to positively set pre-load and fixing with a nut tightened to say 80 Lb's ft of torque, depending on your design. This provides a far stiffer installation.

People use cartridge bearings for a reason. On the other hand, I think Grand Am Prototypes sometimes use taper rollers.

Brian

[Brian Evans]

I thought of some really old school stuff that might amuse... Triumph Herald front uprights were common for use in F1 cars up till the early/mid 1960's. The design used taper roller bearings in a live hub on a axle bolted (with a taper) into the forged steel spindle/upright. The inner seal was a felt ring, the outer seal was a metal cap tapped into a recess in the hub face. The upright typically used spherical joints in single shear on the bottom and a ball joint (or the upgrade was a rod end) in single shear on the top. You could use those and say its an homage to someone...

Brian

[NetKev92]

As much driving time as most FSAE cars get, you almost don't need seals at all. Like he said, felt was the oldschool way to do it. Trailer axles often don't have anything more than a thin sheetmetal piece on the hub a few thousandths clear of the stationary axle. The mechanical guard keeps the largest pieces of FOD out and tries to keep some of the grease in.