So overwhelmingly popular that you can't find any!!That probably explains their overwhelming popularity. I thought it would be more to do with their more compact use of space, lack of requirement for reduction drives, transmissions and associated losses, reduced weight etc.
Silly me!
Sorry, i thought I posted this on the Non Road Going thread.For something car sized and operating at highway speeds - CRAP
500 kg is car sized - and yes if you want it to go fast then you should run six driveshaftsSorry, i thought I posted this on the Non Road Going thread.
Oh, I did!
Tesla are very clever, however that is a CAR!
Did I fail to mention this is an off road 6x6 that only weighs 500kg. How would you suggest that I drive six wheels without having motors on the hubs? Run six axles and CV joints?
Electric vehicles deal with the same driving conditions as non-electric vehicles, but roadgoing EVs (cars) don't use hub motors. The motors which they do use are well sealed and at least splash-proof, and likely "waterproof" for minimal immersion for a limited time.So far, we cannot find any wheel motors that have a decent IP rating. Why is this? Do electric vehicles not go through pools of water? Do they not get submerged up to the hubs?
Hub motors are popular in electric bicycles, and some types of equipment (such as some robotic devices), but rare otherwise. I realize that this thread is about a robot vehicle, but this should be understood to be a specialty application.That probably explains their overwhelming popularity. I thought it would be more to do with their more compact use of space, lack of requirement for reduction drives, transmissions and associated losses, reduced weight etc.
Why do so many people seem to think that Tesla is the only manufacturer of electric cars? Weird...Tesla are very clever, however that is a CAR!
Did I fail to mention this is an off road 6x6 that only weighs 500kg.
Assuming that you have suspension or steering at each axle, then yes... with a motor or motors not mounted on the hubs you would need CV joints. There have been many 6X6 vehicles of various sizes, and nearly all of them have three conventionally powered axles (either live beam axles, or independent suspensions and jointed drive axles).How would you suggest that I drive six wheels without having motors on the hubs? Run six axles and CV joints?
Motors need cooling. Liquid-cooling a hub motor means coolant lines to and from the motor, which would be an unpopular choice. Cooling entirely via a sealed housing is not very effective. That leaves most small motors air-cooled, and so likely incompatible with even splashed water, let alone submersion.While we would love to use hub motors, we can't find any with an IP65 or IP67 ingress rating. As this will be used in hostile, muddy wet environments, this is a requirement.
So far, we cannot find any wheel motors that have a decent IP rating. Why is this? Do electric vehicles not go through pools of water? Do they not get submerged up to the hubs?
Since there aren't many small able-to-fit-in-a-hub motors available, in my opinion, a reduction drive into the hub may be a better option because it increases the range of motors you can use (ie using the reduction gear to gain as much torque as you need)The only question, which I attempted to highlight in my first post, is whether we will have to design our own reduction drive into the hub, or whether we use hub motors.
Cost is not an issue as we have an appropriate budget.