Design/Sourcing consideration for high frequency direction reversal?

[xander18]

Hi everyone,

I feel like I must have forgotten something from college but my old textbooks/notes aren't turning anything up. Neither is my search-fu or bearing manufacturer documentation.

I'm specing a bearing for a roller follower in a reciprocating mechanism (designing for 50 Hz max frequency). These rollers will be low voltage electrical contacts so the normal force on the bearing is whatever spring I'd like to put in, or whatever spring constant will provide enough friction to prevent slip. I've done calculations on the motion profile (and velocity/acceleration plots) of both the linear assembly and rotation of the bearing. But I either never knew or forgot how to apply this to bearing design. I've found bearings that are rated for significantly higher speeds than the maximum rotational speed in my system but I feel like the high acceleration and reversing direction must have an effect on the bearing, right? Or if I'm within the maximum speed of the bearing will I be okay?

Thanks for any tips/thoughts you folks can offer. I don't need a definitive answer, more than happy to spend some time reading texts/technical papers, just looking to get going in the right direction.
-Xander

Edit: I found this webpage, I will work with these equations for now.

http://www.rbcbearings.com/camfollowers/speed.htm

 

[dvd]

My suggestion is to contact Graphalloy. They are good folks and may have solved your problem before. They make graphite alloy bearings and electrical contacts. They may be able to help combine your follower and contact.

http://graphalloy.com/index.html

 

[dvd]

You may find some help in this book - run ocr on it and search for text.

http://www.camcoindex.com/svcman/moonbook.pdf

An issue which you may be facing is the rapid change in direction of rotation of the follower, or crossover.