We are in the planning stages of a Mechanical Engineering senior design project. We have been tasked to build a multi-person pedal powered bus.
Anyway, I want to run a peerless 820 and I have some questions.
#1) I read somewhere that these things will run upside down (820-017) because they are grease lubricated not oil bathed. Could I run one unmodified rotated 90 degrees backward from the original position. So input shaft pointing torwards rear of vehicle instead of vertically?
Yes, according to Peerless engineering, you can run these transaxles with the input shaft in a horizontal position. If you do this and run axle-down, I would recommend that you do as the racers do and also add 6-8 oz. of Lucas Gear Oil Additive to the Bentonite grease to better protect the shift mechanism and cluster gears.
#2) Do I need to run a viscous clutch (slips while engaging until fully engaged) or can I run an on/off electric PTO clutch?
I suppose you could run either one, although the electric clutch will produce more of a shock load on the transaxle. My recommendation would be to use a belt/idler clutch, like riding mowers.
#3) Can I shift on the go? Stock lawn tractors usually require you to stop to change gears. However, these 820s seem like they should shift while moving forward if supplied with a clutch.
You can shift on the go only
if you declutch and have the pedalers momentarily stop pedaling to remove the input load on the transaxle.
#4) Will it be strong enough to move 3k lbs with a much slower than average acceleration? Assuming outboard brakes and fully supported (no shear load) on axle shafts?
That's considerably more maximum load than it was designed for but since it will be a very low-speed input, you should be okay. The 820 is designed for "ground-engaging attachments", so if you're using one to pull a 2-bottom plow, you're approaching that much of a static load anyway.
#5) If it comes to it (hope to design in a way that doesn't require this) could this transaxle withstand being towed at highway speeds in neutral?
Only if you want to replace the transaxle after you arrive at your towed-to destination.
#6) Can I run slightly higher than maximum tire size? I am looking at 180/75-13 trailer tires as my smallest option after accomodating brakes.
Peerless recommends a maximum tire diameter of 23" for the 820. Your 180/75-13 probably aren't much larger than that. Again, with the low-speed application of your bus, it should be okay.
#7) Will it have a reasonably long service life?
Define "reasonably long". The Peerless 820 is the heaviest-duty gear-drive transaxle available, so it's the best choice for this project going in. The only way to find out is to build it and see how it performs.
Sorry, that is a lot of questions. Some of these things I will have to do analysis on to prove them to my sponsor but if it isn't going to work I don't want to waste my time on it. Especially, because I have not been able to get a response from Peerless about the load specifications of the transmission.
Thanks, A lot.
Apology not necessary. "You won't learn if you don't ask." If your sponsor wishes to contact me, that's fine. And if you need further questions answered, feel free to email me. I've helped with mini-bajas in the past. And...you're most welcome. If you do go ahead with this, you'll have to let us know how it works out.
Your only other choice would be to use a transaxle from a small FWD car, but that would be considerably heavier than the 820.
My question: How many people is "multi-person" -- how many pedalers are you planning to have powering this 820-in-a-bus?
Respectfully; Rodney Rom; Rom's Reworks; Butler, MO