centrifugal clutch and transaxle

[whateg0]

Has anybody ever used a centrifugal clutch with a transmission or transaxle? It seems like it would work, and would give you almost hydrostat-like functionality. But if it works, it seems like it would be more common.

My thoughts for a project involve a riding mower, which usually uses a spring-loaded idler as a "clutch" that goes to a transaxle. However, I don't necessarily have a good way of acuating the idler in my design. So, I thought about using a centrifugal clutch, but then I'm limited in my top speed. So, if I used a centrifugal clutch, I could just idle the motor down and it would be effectively disengaged.

Thoughts?

Dave

 

[Scotty370]

Short answers, "No", and "No" !! That said, since I'm reading that your 'designing', (Building from scratch'?), perhaps a variable v-belt type clutch would fit into your plans. Similar to those used in (old?) snowmobiles. The belt rides deep in the drive pulley and high in the driven pulley at idle, then as engine rpm gains, the pulley flanges compress on the engine end and expand at the driven end! Problem I see with a straight centrifugal clutch is that once it engages, the only speed adjustment is what throttle you've got left! A snowmobile bone yard would be a source, 'cause new, they'd be huge bucks! ~Scotty

 

[zzvyb6]

Golf cart.

 

[Scotty370]

ZZ- Is that what they have?

 

[zzvyb6]

That seems to be the way my Yamaha gas cart is set up. Once it get up to operating rpm, the centrifugal clutch deals out the speed to balance the load (hill climbing, extra payload, pulling a trailer, etc.) at a constant rpm I use mine for all around transport of "stuff" on the ranch: hay feed, firewood, fueling tanker, pulling the chipper and dump cart and portable rifle rack. Its a great way to run the dogs out in the field, too. Putting more motor on it would give you a nice CV platform to run a self propelled mower or ground drive implement. Cooling seems to be my only concern about my current setup. They recommend synthetic motor oil if you are gonna run at full power a lot. Maybe a remote engine cooling fan with a thermal sensor on it from a FWD car would improve this issue... There is a parts book for these carts on the Yamaha web site, Just pick a year and a gas type cart. You can see what the powerplant configuration looks like.

 

[Scotty370]

Thanks for the education! A neighbor (country-place) of mine has about 4, both gas & electric, to run around all his mowed trails on some 200ac. The Grand-Kids, think he's the greatest!!!! ~S

 

[Renze]

The Citroen 2CV car (aka ugly duckling) of the 50's, produced well into the 80's, had an optional centrifugal clutch in front of a 3 speed manual. The idea was to be cheaper than a fully automatic. I think the car had a 25 horse 3 cylinder W engine (a flat two with a third upright cylinder) which wouldnt be able to carry the weight of an automatic, and the cost would blow the price up way higher than anyone would give for such a pile of junk.\
Anyways, they advised the 1st gear for hill climbing, 2nd as city speed and 3rd as main road speed (it wouldnt get to highway speeds anyways)

I think they only sold it for a couple of years in the 60's because granny drivers (the main buyer target) would only use the 2nd and overrev it, or only use the 3rd and burn the centrifugal clutch when going uphill.

The Daf car of the 50's (with the Daf Variomatic belt transmission) had only 600cc but was quicker than many 6 cylinder cars of that era, because it was light, effective and the engine kept running at its optimum (the transmission acted not just on input RPM but also on intake vacuum: the car would lower the transmission ratio when you reached cruise speed and decreased engine power by taking your foot partly off the gas pedal, reducing intake manifold vacuum)
That worked great because the centrifugal clutch only had to engage at takeoff, with a low gear ratio, the centrifugal clutch would be fully engaged before the variator would increase its ratio.

 

[Oldmax]

Chushman used a centrifugal clutch in front of a two speed trans. it had a clutch pedel that would disingauge clutch to change gears. The Standred 4 wheelers have some sort centrifugal set up.

 

[BHD]

the variable speed double Vee pulley works reasonable to very well, (depending on the application) as it gears down the low speed and then converts to a higher ratio as it speeds up, (almost an automatic transmission in it self),

a centrifugal clutch does not let the motor have enough speed to get going in my opinion, when I was a kid I built a motor bike and it was not that good, if it would had the variable speed pulley like the units I was trying to copy it would have been great,

you will get in situations that you can not rev up the motor enough to get the clutch to engage solidly as there is to much drag on the motor, but not enough speed,

 

[jamtuc]

Polaris 4 wheelers use a CV Belt drive. Might find one cheap on ebay or craigslist