The idea of stacking two or more Honda Insight IMA motors together in tandem fashion has been suggested by others for powering an EV or for enhancing the Insight's battery only performance. The ORNL study on the Accord IMA motor shows what might be expected and a way in which this type of adaptation may be accomplished. We should be able to make up some end plates, adapters, bearings, and shaft for an Insight setup.
An Insight specific conversion/adaptation probably should 1.) bolt up to existing hardware in a tandem arrangement and/or 2.) use Insight parts in a free standing motor for general EV propulsion. A lot of work has been done by Mike and others on the electronic end and hopefully we should be able to work up some practical motor hardware also.
To begin with, on the Insight ICE engine, can someone furnish the dimension between the end of the ICE crankshaft (IMA motor rotor mounting surface) and the machined surface on the ICE block where the IMA motor is mounted? In other words, how far beyond the engine block does the crankshaft protrude (or not). With this dimension we should be able to work out the critical relationship between IMA rotor and stator.
interesting idea. how many would you have to stack for ev only use?
I see potential in the EV only use, but stacking them with the engine seems not worth it, since that much effort could be spent on an electric motor external to the engine that only drives the wheels.
__________________
2002 Silver MT 225k miles LMPG - 60.8
Best Tank Distance = 722 miles @ 74.2
I think two IMA motors stacked would give 10kw continuous power with a peak of perhaps 30kw if over driven. Enough for a slowish EV and max speed of perhaps 60-70mph.
Three would be better giving 45kw peak and probably 80mph+ top speed
Four would be the performance version giving 60kw and getting on for 100mph I bet.
Four stacked would be about around the width of the IC engine + IMA motor so would fit in the standard space. If they were aligned carefully you probably would only need one set of commutation sensors and could drive them in parallel with a single highpower AC drive say the siemens unit or similar.
Uping the voltage to 200V or so would also boost power.
If you remove the fuel tank and all the other stuff including all the old IMA gubbins you could probably fit a decent battery pack in the IMA compartment possibly split and have some underneath in a box as well.
I don't think it's practicable to use the existing IMA drive to run multiple motors, although it might just run two but would need lots of reverse engineering.
..............
Four would be the performance version giving 60kw and getting on for 100mph I bet.
Four stacked would be about around the width of the IC engine + IMA motor so would fit in the standard space. If they were aligned carefully you probably would only need one set of commutation sensors and could drive them in parallel with a single highpower AC drive say the siemens unit or similar..............
It appears that what we need is a free standing triple stack motor with a mounting face identical to the ICE (which it will replace) to which the existing IMA motor may be mounted and synchonized so that the existing commutation system may be used for all four. In addition, the power bus will have to be extended to include all four motors. The entire assembly should be totaly enclosed because the strong magnets used could accumulate debris over time. Simple provision for water cooling the motor(s) using existing plumbing could also furnish cabin heating when needed. The use of a commercially available motor control unit would remove a lot of uncertainty from the project.
Simple provision for water cooling the motor(s) using existing plumbing could also furnish cabin heating when needed. The use of a commercially available motor control unit would remove a lot of uncertainty from the project.
There is no existing plumbing as the IMA motor system is not water cooled.
The commercially available controller that comes to mind is the Kelly BLDC controllers.
I have looked at this issue for some time, and have 4 of the IMA motors, as well as 15 or more civic power inverters.
The magnetic field issues that Peter and I were initially concerned with do not seem to be a major issue.
I base this on a test of the magnet strength inside the coil assembly, and outside. When the magnets are on the bench, they will yank a hammer out of your hand. When they are in the coil assembly, a screwdriver barely sticks directly on the magnet. This is due to the intense magnetic flux path and narrow gap between the coil structure and the magnets.
I was thinking that one IMA motor for each rear wheel would be a better way to go than to make one motor with two rotors. A single motor on one wheel would probably be all any hypermiler would need.
Sink the flat IMA motor into the body so the motor output shaft lines up with the rear suspension hinge point, and weld a large timing belt sprocket to the rear wheel.
Pick a sprocket ratio that will let the drive do 90 mph at the motors max rpm.
Have a switchover system so the stock IMA motor can be switched to the rear motor, and the stock drive electronics could give an EV mode.(MIMA)
As far as max power from a permanent magnet motor, I am no expert, but understand that the limiting factor is demagnetization of the rotor magnets, as well as how cool you can keep the coils.
Series wound motors typically used on home built EV's can do intermittent burst of 20 or more times the average power, where PM motors need to stay closer to their rated output.
The Prius MG2 is a pretty nice drive motor if more power is desired, it has bearings, sealed case, cooling and a max rating of ~50KW.
The interesting thing about the honda and toyota motors is that the rotors all have about the same diameter.
The more powerful the motor, the longer the magnet rotor assembly, MG2 is about 8 inches deep, compared to the toyota MG1 and the IMA motors ~2.5 "
There is no existing plumbing as the IMA motor system is not water cooled.
The commercially available controller that comes to mind is the Kelly BLDC controllers.
I hope this helps.
It is well known that the Honda IMA motors are water cooled. They are all bolted up to the water jacket of their respective IC engines. In the continuous EV application discussed here, there probably would be even more of a need for cooling than in the intermittant assist or IMA mode in the hybrids. The stacked motor undoubtedly would need cooling and could utilize existing ICE plumbing such as the radiator, heater, etc.
My preference for an AC variable frequency motor controller would be a heavy duty industrial unit such as Peter mentioned. It is my understanding that Kelly controllers should be realistically rated at half their advertised output to be on the safe side. With that in mind, no Kelly controller available today would be suitable for the four stack motor.
Guess I don,t understand why you need someone else to give you that that dimension, if you have the components on the bench, all the pieces required to make the measurements are in front of you, or am I missing something?
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
Stacked Insight IMA Motors
