Centrifugal Clutch in, CVT out

[LocomotiveBreath]

Hello all,

I had the real pleasure to go to Quality Drive Services (local Comet Dist.) today to exchange my Comet CVT for a Centrifugal Clutch. Roy is very knowlegable with many many drive systems, and I look forward to working with him more. We met for over 2 hours looking at many of his designs and talking about the future of Diesel and electric powered vehicles

I've changed my mind about the use of a CVT in our application. (I'm back peddling) and I'm going a very simple clutch/transmission route, and just going a straight Centrifugal clutch.

I was doing some thinking last night and my old dual quad 1963 Buick Wildcat with a Dynaflow came into mind. Buicks back in the late 40's came out with a single speed transmission (Dynaflow) A low range was also incorporated in the transmission, but low never was used in the normal drive mode. See: http://en.wikipedia.org/wiki/Dynaflow


With the very flat torque band of the diesel, I think this will work, and I know I'm going to get from a few people, What the F*&K. Well I'm going to see how it works. I'm not going to use the usual mini-bike clutch, but a new Noram Tri-Lobe Clutch rated up to 50hp. See: http://www.noram-clutch.com/clutchtrilobe.html I'm not looking for drag racing performance.

[darkdemonwolf]

I'm curiuos to see how your idea pans out, please keep us posted.

Wolf

[Byrdman]

You mention the Buick single speed transmission so I'm confused.

Will you be running the clutch and no transmission, effectively having a single gear?

[andrewaust]

Not a bad concept if you can get your gearing right. I remember the transmissions you are talking about - the fluid connector (Torque Converter) was the reason for the transmission using only one gear. They tended to have a bad reputation for slow acceleration.

Fluid connection is a great idea if you can get it right though, some manual semi auto boxes that came out in some Leyland buses used a torque converter with a manual pneumatic change box and proved ultra reliable. Like the saying goes - never say never - good things sometimes come by chance.



Cheers


Andrew

[LocomotiveBreath]

The Dynaflow and centrifugal clutch both have a torque multiplier given off in heat, either hydraulic or friction.

I've owned several centrifugal clutch vehicles, and with the efficiency at close to 98% & 99.5% with a poly-cog belt vs. the CVT claiming 92% at best, I'm sure this will work just fine. My Hatz and Ruggerini have 31-33ft lbs torque the Daihatsu 954DT has 51-55 ft lbs at start of clutch engagement @1400-1500rpm.

I also have sourced a small Cushman sized 50 hp capable 2 speed w/reverse transmission that will be available in the up coming year and that will be incorporated if I need a lower gear is necessary. I'll be gearing my bikes at a 75-95 mph top speed.

Jack rabbit starts are not my concern at this point.

In my younger mini-bike days, we had built a very simple very large cushman sized mini-bike (Briggs and Stratton 13hp direct drive via centrifugal clutch) and it would do 60 mph+ and had tons of acceleration and power. My little Taco 3hp would do 25 and neighbors 3.5 hp Bonanza was sold because him and his friend were ticketed for doing 43 mph. This was also at a 7400 ft elevation in Flagstaff AZ.

It dawned on me that most CVT applications are geared for mountain climbing capabilities or narrow power/torque bands.

If this works, we might be able to rethink the more complex installation of a CVT.

I’m trying to find the torque chart of the Yanmar and clone L100 engines so I can do some calculations.

Dave

[andrewaust]

Yeah you don't get much happening to quick when starting off - especially the diesel singles

It's not unheard of having a bike with only one gear - I raced Solo Speedway bikes back in the 90's, 75hp - no gears or brakes, and the power to weight was incredible = acceleration was something you had to experience to appreciate - totally opposite to chuggy

If your looking for Yanmar/clone L100 torque charts etc, just do a search on the Yanmar site: http://www.yanmar.com.au/industrial/la_ ... l100ae.htm

Be sure to keep us posted how it goes, as it's an interesting idea you have.





Cheers



Andrew

[LocomotiveBreath]

I received my Centrifugal Clutchs (2) yesterday, Noram built these actually on 3/27/07, they are fast, and one day shipment. I thought I'd give you a size comparison with your inexpensive basic centrifugal clutch most people think of, this one is set to engage @ 1430 RPM
It is rated up to 50hp, if you need a clutch larger, look at these puppys, what I'm doing is nothing new.
http://www.crower.com/pdf/189-196.pdf

[smokyjoe]

Saw this old post--- Did you ever get this clutch contraption up and running? Looks interesting if you've got enough bottom end torque. I searched and couldn't find a follow up and curiosity got the best of me!

Kind of like the time when my transmission wouldn't shift into 1st or 3rd- stuck in 2nd. Slip the clutch and I was off, once I got up to speed all was OK to about 40 Mph, above that I'd turn up the radio and let the engine scream. Finally fixed it and got another 50,000 miles out of the car before it rusted out from beneath me.

[LocomotiveBreath]

I got the old Ruggerini/Honda up and running back in Sept. of 2007. 30,000 miles and five (5) sets of clutch shoes @ $100 a set later, clutch is sitting on a shelf while I get my Hatz/Dnepr on the road.

Did it work? It got me on the road, better fuel mileage than a CVT, could have used a 2 or 3 speed box to be more user friendly, stop and go traffic heated the clutch up, starting on hills was a pain.

Dave

[smokyjoe]

That's a nice looking bike, even if the clutch didn't work out well. Yea, a little 2 or 3 speed would have been nice, kind of like my old Chevy II with the 6 cyl and 2 speed auto trans. It would start off at pretty high RPM, then shift and be back down to about 1,000 rpm until it crawled up to speed but it worked well. Maybe a 2 speed and the Centrifugal would be work well on a Diesel if there weren't a lot of hills to climb due to the Diesel's narrow power band, unlike the old 194 Chevy 6.

Is that an old '80s CB350?

Take care,
Brad