Another way you can gain efficiency (without adding gears) is to switch between a parallel (current to both the armature and the stator) and series (armature and stator in series). It does not alleviate the mechanical losses at higher speeds, however. This method was used on streetcar motors so they had good starting torque and could also go faster when there were fewer stops. You could feel when the motor arrangement "shifted."
That only works for motors with wound rotors. Most (all?) modern EVs use sophisticated reluctance, induction or hybrid motors that don't have a wound rotor.
The use of gears is preferable and the best because it reduces the complexity of sensitive electronics, reduces energy consumption very significantly, increases efficiency and effectiveness, and limits losses in the complex electrical system. Controlling the output while keeping the input constant is best.
Anybody else old enough to remember the General Motors 2 speed Powerglide transmission? Wouldn't it be interesting to fit the Inmotive transmission concept to a gasoline or diesel powered car or light truck? The Powerglide was very reliable, but quite heavy. The Inmotor design looks like it might be much lighter than conventional automotive transmissions. Certainly, there needs to be an alternative to the notoriously unreliable, belt-driven CVT's now sprouting up everywhere.
Hi Grey Jay. Yes, the Ingear can be applied to gasoline engines too, but it's not optimized for the power and torque curves of a gas engine. That's why you see 8 and 10 speed automatic transmissions coming into the market. We could put two Ingear units together for a 4-spd transmission though.
Oh yes. Poweglide 2-speed is a combination torque converter + epicyclic gear train. It is not unlike the model T Ford transmission - also a 2-speed ( + Reverse) epicyclic gear arrangement. The Ford used foot-operated clutches to effect gear changes; the Power-glide uses hydraulics to operate the clutches. With electric motors, you would not need the torque converter for low-speed torque multiplication.
If you can connect two of these together and synchronize them so that one of them shifts to the smaller sprocket at the same time as the other one shifts to the larger sprocket, and vice versa, then it would work equally well in both directions and regenerative breaking wouldn't be an issue.
I don't get it - how does that presumably-spring-loaded idler not absorb torque in either the regen or the acceleration modes? If I picture the smaller upper pulley as the motor power input, it makes sense that the idler will, well... idle properly. But if the direction of torque changes, or if the motor goes to apply power in reverse (same idea), it'll pull against the idler and the belt will relax and not transfer torque. Seems like a ridiculously basic problem that no engineer would've even contributed any time to, with a flaw like that, but... what's the solution?
Hi Jake. Thank you for your question. The number of segments in the above video is just one design that we've proven to work. However, more or less segments could be used, depending on the application. Thanks!
Hi Kirk. Thanks for your comment. That's an insightful observation and a concern we also had when we started the development. That's why we made the decision to do full vehicle trial to show that the stresses can be controlled in a real application. The transitory stresses are controlled by the guiding segment's geometry and are thus able to be calculated, predicted, and managed. Although not shown in this video, we have other iterations with flexible geometry tailored for different applications.
The difference between a derailleur and this transmission is that this one keeps the chain straight. Cross chaining in a derailleur arrangement wears the chain quickly.
This "contraption" may be efficient whatever, but to me, this is just adding something to add to the list of maintenance items. Just looking at that chain/belt, it's obvious you have an item that requires it. Can't we just keep things simple? Electric motor + Wheels. Done. Even my 9 year old see it as simple as that.
Simple is not always more efficient. That's the reason there are gears in a car or even in a bicycle. An electric car, OTOH, doesn't usually need different transmission ratios, but only until ypu reach certain speed. Then it's useful to lower the engine RPMs.
Credo che sia più bello che pratico.... Saltellamenti nei cambi marcia son difficili da evitare e alla lunga si a usura. Preferirei un monomarcia su una elettrica
I see mechanical issues with this design that will manifest themselves over time and use. The slider pins will wear from constant shifts. The link chain will stretch with normal use. The chain will become longer, link to link. That will result in a less than desirable fit up to the segment gears. Then both the chain and the segment gears will wear. The hydraulically stabilized idler assembly will have little to no effect at reducing that abnormal wear. It's a cool idea while it works, but i believe it will be an expensive item to maintain and repair. That cost will inevitably fall to the owner of the vehicle after a few years. Read up on problems Nissan owners have with their CVT transmission cars.
It would seem to me that this should be tried on electric bikes first, get a chinese partner to manufacture it and get it on a few bikes with either belt or chain drive (it seems that either would work but don't know if gates belts produce a long enough chain) and then you can get people accustomed to the idea. Most ebikes are used in urban invironments and 2 speed is usually good enough, and since there is no meshing of gears against chains it should work with higher torque ebike motors.
Износ на подвижных направляющих будет дикий, плюс переключение на дикой скорости у этой коробки нет будущего, вариатор надежней его будет , развивайте планитарный вариатор от приуса вот где будущие
