tndr_1 said:
But anyways… I am about to do the first real test runs on real roads this weekend.
* I have found correct hall/phase cable combo
* I run it at 60V
* I added 80A fuse at battery output
* I will add a current monitor display inside the cabin to be able to see how the current behaves while rest driving
* I will add a temperature sensor to the motor, but sadly not in the same enclosed area that the windings are in because they are hard to reach without dismantling the whole motor installation on the differential.
What more should I have in mind?
* check if phase cables get warm
* check if outer motor shell (aluminum) gets warm
How warm is OKEY?
Sorry for hte long long delay....So: generally if a motor is getting towards boiling water temperatures, it's probably too hot (being overloaded in some way, or is at too high a load for the speed it is running (wrong gearing), wrong phase/hall combo, etc).
If the phase wires get hot, they're either too thin, or the above overloading/etc is occuring, drawing more phase current than should be necessary--controller itself will also typically get pretty hot in the wrong phase/hall combo scenario.
The best place for a sensor in the motor is at the windings, but if that's not possible, the next best is the casing that the windings are mounted to, at the point they are mounted there, where the least airflow occurs over it. (assuming the motor is an inrunner with the stator on the outside and the rotor on the shaft inside).
tndr_1 said:
What I can do is to put the original differential in reverse gear which makes it output an higher RPM.
These are the specifications of the differential. The DC-motor should output 580 RPM at 48V but now I run it in 60V. Do u think I should run the differential in reverse instead? Of course switching the phase wires to run the BLDC motor reverse also.
Please note that my BLDC motor has planetary gears which brings it down to 580 RPM.
Forward gear
Gear Ratio: 0.4225
Input: 580 RPM
Output: 245 RPM
Reverse gear
Gear Ratio: 0.5965
Input: 580 RPM
Output: 346 RPM
Depends on what you're trying to do. If you need to go faster for the same motor speed, the reverse gear would do that (assuming you can just change the motor controller to reverse mode) by the gearing ratio you have between F and R (346/245). Won't reduce the motor load, though (will go up because of faster speed needing more power).
If you're trying to reduce the load on the motor to prevent overheating, using the reverse gear to keep the same speed you already have should then reduce the load on the motor, I think. (am still tired from being sick, so certain things are hard for me to keep straight in my head ATM).
The idea is to let the motor spin faster for the same vehicle speed and same power requirement from the motor. It lets motor current drop, which means less motor heating from that.
Oh, also, if you haven't already done regular mechanical maintenance on the bearings and gearing of the drive system past the motor (diff/gearbox, axle bearings, etc) I'd recommend that. Bearings should all spin freely; if they don't they add to the load the motor must drive without doing anything for you. Same thing for the gearing--if grease or oil has aged or become contaminated, it may cause excess drag or wear on the gears (and their bearings).