I am not an engineer, but I'd like to understand the physics and design choices in the following application. I am putting new bearings in my front wheel hubs for my kart. Stock bearings are deep groove. This makes sense to me as a wheel's primary job is to spin. Then I think about cornering forces with grippy tires. I imagine that that puts a large axial load on the bearings as well. So why not angular contact bearings? What is going on here that I don't understand/am not aware of? I read that angular contact bearings have more radial friction. Does that matter when the max rpm of the wheel is probably 1/10 the rated rpm of the bearings? I read that angular bearings are directionally biased, but if there are two per hub, could you just put one in each direction? I read that angular bearings need a pre-load, and the bearings in my hubs are just a friction fit. Would this be a problem? Could a preload be applied with retaining rings and a spacer between the bearings? What kind of bearings are in racecar hubs?
Googles: //store.drpperformance.com/drp-premium-finished-wide-five-bearing-kit/ From a timken guy I used to work with: "at operating temperature, ideally you have a line to line fit" in other words, no preload, no play. Now go figure out what your actual operating temps are on your actual parts and materials and assembly practice... Yay fun
Plus then you have dynamic loading calculations in said operating environment and material behavior, etc. The FEA is easy, gathering the input data in this case is the hard part I don’t know how the cart spindles are but are the bearings retained or get an amount of torque sufficient to pre-load them appropriately? Radial bearings don’t like to have much change in the pre load which is why deep groove are often used as they are more forgiving because of the symmetry of them. This is often why they are used on products with more of a constant side load (in relation to the bearing). Other factor is the forces applied on the inner and outer when cornering but your thought process of mirroring them is in the right direction from an engineering standpoint. Think of bearings on your triples for example and direction they are. Post up a link to a similar spindle / cart and I can so some rough math just because now I’m curious what the loads would be
to put it in a simple term,the angular bearing will wobble in a staight line.the deep groove takes care of both situations.
i agree,the difference in the two bearings for this particular purpose would be minimal i would think.
A lot of factors come into play here with a big one being pre-load, then various dynamic loads at various temperatures, etc. I’m about to head on the lake so no math for me but simple answer- especially with a critical part is go with a known solution.
Wow, I underestimated how deep these waters were. I don't even understand most of the responses. I will go with SOP and get the deep groove. As for loads we are talking about a 400# kart and driver. Spindle is 17mm, bearings are 17x35x8-10 range. Racing is endurance on paved road course. I asked bc I am a driver and usually do arrive and drive stuff. Now I'm starting to learn about kart setup, and while I realize this is a motorcycle racing forum, I am familiar with this place and know that there are some really smart people here, both in life and racing. Onwards with the journey!
