Eric Twiest Brad Pierson Hieu Nguyen Matt Miiller February 14 th , 2007. Wheelchair Gearing System Project Proposal. Problem Statement.
When operating a manual wheelchair it can be very difficult for the user to traverse an incline plane or ramp. In addition some people don’t have the strength required and dangers exist, for example rolling back down a ramp. The goal of this project is to develop an attachment or modification to a manual wheelchair which would provide the user with a mechanical advantage when traversing a ramp.
Calculated Forces, Torques and Effective Gear Ratios.
-Forces: Fincline=136.1 lbf, Fflat=120 lbf
-Torques: Tincline= 816.6 lb·in, Tflat=720 lb·in
-Angular Velocities: ωincline=38.58 rpm, ωflat= 43.77 rpm
-Effective Gear Ratio:
-Design for 2:1 ratio to guarantee for factor of safety.
Assumptions made( 200 lb person, 0.5 hp input, wheel diameter = 24 in)