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In Reply to: How about this for a thrust pad material? posted by Ugly on September 9, 2017 at 15:02:56:
Who let the engineers out? The calculation is whether the plastic has sufficient strength and stability to resist the body-contact "Hertzian" stress from the ball sitting on it. This paper has a pretty clear treatment of the Hertzian stress problem: https://wp.optics.arizona.edu/optomech/wp-content/uploads/sites/53/2016/10/Tutorial_LeCainNicholas.pdf
(use R2=infinity for the case of ball on flat surface). Note they conclude the stresses calculated using this approach are conservative. See if the plastic can take it. If it's safe working range is exceeded the pad might tend to flow at the contact. The plastic you posted seems to have a recommended (working?) surface pressure of <7000psi. I'm thinking it's a no-go but I'm awful conservative. You could make it easliy replaceable maybe.
The P-V wear is probably a negligible factor (if that's the right number for a ball against a flat pad?)
I looked at this bearing problem once for something else and decided it was just too hard, and cheated and revised the design...
Some high quality TT bearings use solid sintered tungsten-carbide discs whose modulus is probably 50x that of plastic and hardness 10,000 x. We're talkin' 1800 knoops. Like the little cuties in the link below. You're gonna do all that work, use the best stuff.
Read this guys TT bearing design specs-- stumbled on this writing tonight. These babies are worth the $600USD: http://www.mikenewaudio.com/bearing.php
Good luck!
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Follow Ups
- RE: How about this for a thrust pad material? - mr.bear 09/9/1721:13:33 09/9/17 (15)
- RE: How about this for a thrust pad material? - Ugly 07:42:16 09/10/17 (3)
- RE: How about this for a thrust pad material? - mr.bear 12:01:28 09/10/17 (2)
- Are any of these materials better for the accidental shock impulse loads? - Ugly 18:51:48 09/11/17 (0)
- RE: How about this for a thrust pad material? - Ugly 13:56:11 09/10/17 (0)
- RE: How about this for a thrust pad material? - Tre' 07:26:44 09/10/17 (10)
- RE: How about this for a thrust pad material? - mr.bear 11:03:22 09/10/17 (8)
- RE: How about this for a thrust pad material? - Penguin 22:43:33 09/10/17 (0)
- RE: How about this for a thrust pad material? - Tre' 16:37:52 09/10/17 (6)
- OK, 16.5mm will fit but now.... - Tre' 18:58:36 09/10/17 (5)
- This is the advice I got to remove the ball - Barry 19:13:12 09/11/17 (1)
- RE: This is the advice I got to remove the ball - Tre' 20:29:51 09/11/17 (0)
- RE: OK, 16.5mm will fit but now.... - Not Yet There 10:55:48 09/11/17 (1)
- Got it, thanks - Tre' 11:06:56 09/11/17 (0)
- Should sound terrific and... - Barry 07:11:31 09/11/17 (0)
- RE: How about this for a thrust pad material? - Ugly 07:54:22 09/10/17 (0)