ChrisDanger
Mechanical
- May 15, 2012
- 33
I'm helping a friend design a coilover shock for a wheelchair for his nephew. He suggested using an o-ring or seal friction damper, but after not finding much information to aid in design I wondered if using hydraulics would be viable, but I couldn't find much information on that either. I'm wondering two things: Which would be cheaper in the long term, and where can I find information about design details? He works in a machine shop and will be fabricating everything himself.
The way I see it, a rubber damper might suffer from wear and need friction elements replaced fairly frequently (also giving a declining performance), whereas the hydraulic damper might be (slightly?) more expensive to produce but last longer between maintenance schedules (and give more uniform performance over time).
Both designs have stumbling blocks. I can't find any guidelines on gland dimensions, seal material, or required surface finish for any friction dampers. And for the hydraulic shock how is oil inserted and topped up? I imagine some kind of valve but again, I couldn't find any information on this either.
Preliminary designs are below for reference.
Elastomeric:
Hydraulic:
The way I see it, a rubber damper might suffer from wear and need friction elements replaced fairly frequently (also giving a declining performance), whereas the hydraulic damper might be (slightly?) more expensive to produce but last longer between maintenance schedules (and give more uniform performance over time).
Both designs have stumbling blocks. I can't find any guidelines on gland dimensions, seal material, or required surface finish for any friction dampers. And for the hydraulic shock how is oil inserted and topped up? I imagine some kind of valve but again, I couldn't find any information on this either.
Preliminary designs are below for reference.
Elastomeric:
![URL]](https://res.cloudinary.com/engtips/image/fetch/w_800,c_lfill,q_auto,f_auto,g_faces:center/[URL unfurl="true"]http://u.cubeupload.com/ChrisDanger/Elastomeric.png[/URL])
Hydraulic:
![URL]](https://res.cloudinary.com/engtips/image/fetch/w_800,c_lfill,q_auto,f_auto,g_faces:center/[URL unfurl="true"]http://u.cubeupload.com/ChrisDanger/Hydraulic.png[/URL])