Here’s something that I have wondered about that I feel like I’m missing something.
Why don’t most eskate use any kind of active cooling on the motors and ESC?
The background story is: I see many comments and discussions about going to bigger motors, 80xx etc, for more torque/power, hooked up to battery + escs that can’t even sustain half of what the motor is capable of handling. Huge, bulky motors capable of 6-8kWs each that theoretically would require 20p+ packs with watercooled ESCs. Since motor torque is directly related to amperage, increasing motor size at the exact same power input would only realistically only increase torque by a very low amount, at the expense of a motor 2-3x the weight. The only conclusion to me then is that the bigger motor can sink more heat due to more material before losing efficiency and torque to overheating.
Obviously heat is a big issue with any electrical drive system, almost all electric cars use some type of fluid cooling on the motors and even battery. Liquid cooling is a bit inhibiting for eskate, but why not forced air cooling? The brushless out runners we use originated from RC things, yet there are companies like scorpion motors making outrunners in the 40mm can size that can hold sustained wattages higher than most 63xx eskate motors. The difference is 1: trading torque for RPMs, then gaining the torque back through high gear reductions (disregard the erpm limit for now), and 2: machining a centripetal fan into the motor casing to pull a lot of airflow through the core.
Now why does no eskate motor use the can as a fan to eject heat? Or any kind of active airflow for cooling? (including the esc? My RC cars have fans on the esc, why not eskate?). A smaller motor can achieve similar power outputs as a large one (to a reasonable extent) as long as the smaller motor can stay cool. Dust/waterproofing is not an excuse here. Outrunners are surprisingly resilient to dust/water ingress as long as the vents are of reasonable size. And ESCs can be waterproofed with protruding heatsinks and fans attached. If a $60 RC esc with an active cooling fan can be driven underwater, there’s no reason for eskate escs and motors to have the same?