CVT transmissions for buses

CrabbyMilton · November 10, 2021, 09:54:35 AM

Yeah it seems that MCI bypassed the whole hybrid option and it going 100% electric on the J4500. Time will tell and as those batteries get old they may put some operators off. But I think those use some form of a CVT or perhaps not. You idea sounds interesting.

chessie4905 · November 10, 2021, 10:54:53 AM

100% electric would use wheel motors not a cvt. Good benefit on heavy vehicles to control downhill speed and reverse current into batteries

6805eagleguy · November 10, 2021, 04:54:25 PM

I believe certain models of case tractors have cvt's. Not sure on hp but above 400 for sure.

luvrbus · November 10, 2021, 05:25:29 PM

Quote from: 6805eagleguy on November 10, 2021, 04:54:25 PM
I believe certain models of case tractors have cvt's. Not sure on hp but above 400 for sure.

CVT has been in farm tractor for 10 years ,John Deere,Case,AGCO and others have the CVT,I know Cat has it in some loaders like the 966 and small skid loaders

chessie4905 · November 10, 2021, 05:36:06 PM

I would imagine their belt is a lot more robust than ones in cars, since packaging space would be less limited. Also rpm range would be a lot less than in cars.

windtrader · November 10, 2021, 06:59:38 PM

ditto Cheese. CVT is old school. Transmissions are gone in EV. Just bolt the motor to the wheel or drive axle. It is definitely a big shift in thinking going to EV as they provide 100% torque from the first spin of the motor and being direct drive in general. Motor to wheel are basically locked together.

Jim Blackwood · November 10, 2021, 07:29:46 PM

I like the idea of putting the motor inside the wheel but I don't suppose that will become practical until motors can be made much lighter. Maybe something like the centerless wheels on video game vehicles. Probably still a couple decades away from that one.

Jim

luvrbus · November 11, 2021, 05:35:46 AM

Fossil fuel power will be around for a long, long time to come, there is nothing in your daily life that is not tied to petroleum.EV's are just a small part of life to me and not enough to worry about

CrabbyMilton · November 11, 2021, 06:41:03 AM

You are certainly correct. The BEV movement is still in the early stages but will increase over time. LION is starting to push a BEV ambulance now. BEV's may work fine for short trips around town like taxis, school and some transit buses, airport car rental/hotel buses and local delivery trucks. But emergency vehicles I would be skeptical as well as that new BEV J4500. Not sure about a long distance charter trip in one. Especially when the batteries get old and don't like to hold charges well anymore.

chessie4905 · November 11, 2021, 07:27:17 AM

I think the motors used in bell housings for start-stop technology is a great start for wheel motors that they'll be using in vehicles and have had a few years of use to demonstrate their reliability.

windtrader · November 11, 2021, 09:22:18 AM

Old news. Lookup vehicle hub motors. There are plenty in small utility vehicles and many are used on bikes and motos. I'm guessing the fundamental problem exists in increasing power in the reduced size, maybe economies of scale costs too. Then there is the obvious, practical factor of needing more hub motors.

luvrbus · November 11, 2021, 09:56:02 AM

Quote from: windtrader on November 11, 2021, 09:22:18 AM
Old news. Lookup vehicle hub motors. There are plenty in small utility vehicles and many are used on bikes and motos. I'm guessing the fundamental problem exists in increasing power in the reduced size, maybe economies of scale costs too. Then there is the obvious, practical factor of needing more hub motors.

Hub motors use old technology from the 20's to get power and speed using the planetary gears or some call it the sun gear they are not direct drive.You ever seen a electric traction motor on train engine you could call those hub motors they been around since the 40's some times what is new is actually old technology

Jim Blackwood · November 11, 2021, 10:01:43 AM

I think rail gun technology could be used on hubless wheels. Either embed magnets in the rim or use induction. Maybe a 3d printed polymer rim with conducting traces printed in place. Then a mating stator connected to the car. We have the technology to do that now, but it'll probably take 20 years to perfect it.

Jim

luvrbus · November 11, 2021, 10:14:48 AM

When I worked for Stewart/Stevenson back in the day they were working on induction motors for the military. They were neat but after 2 years and no telling how money they were tossed in junk pile

Tedsoldbus · November 11, 2021, 12:35:02 PM

My wife misses shifting of the Allegro bus. Probably because she didn't have to. Big Cat engine and 6 speed Allison. She could put it in "D" and just drive it. I get to do most of the driving in the Prevost because I do a fair amount of manual shifting of the HT 740 to keep it in no lug RPM range, That took a bit of getting used to, but I actually like doing it. I would think a big CVT might work on a newer bus if designed for it. But try to add to an old Detroit? Could it keep RPM in the 2000 range? Guess we won't ever know. I expect a Biden mandate any minute the Buses must be electric. At least we have enough space for the batteries and enough roof for the solar panels!!