1/19/14 10:42 AM

i watched this video of the assembly of cartridge bearing assemblies, but i cannot for the life of me figure out the magic of how the polished bearings are jammed into the space between inner/outer races.

that race-bearing-race fit is an interference fit...which is how radial bearings stay together...but if the bearings and races are fully polished/finished before final assembly...how are they all combined together w/o some sort of deformation being required?!

just calling it a "ball pusher" as they do in the video doesnt help me understand how that insertion really takes place...help a brother find some Truth!

https://www.youtube.com/watch?v=b6svVy1lYOA

1/19/14 10:51 AM

found this vid...the bearing spacer is key...w/o it the bearings can all jam together on one side, allowing the inner race to slide into place.

duh.

https://www.youtube.com/watch?v=KsGh0wbJWtQ

1/21/14 7:23 AM

That's good to know, as I was afraid someone was trying to bust your balls (bearings).

1/22/14 8:37 PM

how in the hell do you get all them bearings inside of those races?!

i only see it with full ceramics, so maybe there's some difference in the mfg process that makes this possible? definitely a head-scratcher!

1/23/14 4:45 AM

The races are oversized then deformed by the press into the final shape which captures the balls.

1/23/14 7:57 AM

very skeptical. bearings require precision-ground races to function at all.

there's no way races can be resized, ceramic in particular, while maintaining that high a level of precision around shape/geometry *and* not damage the fragile surfaces of the bearings and races themselves.

also, ceramics are an incredibly brittle class of material -- to call it "non-malleable" is a serious understatement.

i just emailed VXB to see what they can/will share.

also, i found an example of cageless stainless bearings...so it's not material specific to ceramics:

1/23/14 8:16 AM

filling slots that are machined to a spec requiring heat/cooling for assembly.

the slots are in the inner/outer races and must be aligned for bearing insertion...in addition to significant heat added to the outer race and significant cooling applied to the inner race...with that combination of alignment and temps, the bearings will go in. back @ room temp, everything stays locked in place.

doesnt look to be relevant for cycling applications: "Full complement ball bearings are specified for high radial load applications, often in pairs. Axial load ratings are reduced because of the fill slots."

1/23/14 1:14 PM

Walter, when are you going to get to the bottom of this? ;)

1/24/14 9:12 AM

How difficult it's been not to post this?

1/24/14 11:40 AM

Andy, that shot cartridge illustration is really old. Overshot wads, and fiber over-powder wads haven't been used since the '60's.

1/24/14 12:33 PM

It's closer to 100 years old, but it does have to do with ball bearings and cartridges...

1/24/14 2:47 PM

Actually Andy's cartridges are used in bottom brackets, both to initiate the final sprint and to dispatch opponents.

1/24/14 2:48 PM

nm