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Running small motor in reverse?

Posted: Wed Oct 02, 2019 12:18 am
by cloudy
Thinking of a running a small motor back to front in the car - aside from any transmission issues with running in 'reverse'. Can it generate the same torque in reverse? Can the phases be swapped to have the motor/logic board think it's running forwards?

Thanks!

Re: Running small motor in reverse?

Posted: Wed Oct 02, 2019 8:42 am
by Kevin Sharpe
cloudy wrote: Wed Oct 02, 2019 12:18 amCan it generate the same torque in reverse?
Yes... see here;

viewtopic.php?f=11&t=109

Re: Running small motor in reverse?

Posted: Wed Oct 02, 2019 11:33 am
by joromy
cloudy
Doesn't matter, but if you want the correct DIR shown in the inverter or display.
You must swap phase in motor/PWM or IGBT driver, remember to swap encoder to!!!

Re: Running small motor in reverse?

Posted: Thu Oct 03, 2019 3:14 am
by sfk
cloudy wrote: Wed Oct 02, 2019 12:18 am Thinking of a running a small motor back to front in the car - aside from any transmission issues with running in 'reverse'. Can it generate the same torque in reverse? Can the phases be swapped to have the motor/logic board think it's running forwards?

Thanks!
It's fairly simple to swap 2 phases or instruct the inverter run different phase order AFAIK.

BUT do be aware that some motors and their housing designs require the internals to be running a certain direction for a majority of he time. Case in point: the Nissan Leaf transaxle housing has a oil reservoir that depends on the main gear to "throw" lubricant into it. This won't work in reverse.

Re: Running small motor in reverse?

Posted: Thu Oct 03, 2019 7:25 am
by cloudy
Thank you all! I had the same concerns about oil distribution or gearbox forces in permanent reverse... Glad to know electrically it's possible without performance penalty..