When driven by coupling: fan speed = motor speed.
For V-belt transmission: fan speed/motor speed = motor pulley pitch circle diameter/motor pulley pitch circle diameter.
There is probably no other transmission method. If there is gear transmission or sprocket chain transmission, the algorithm is similar to the second one.
The fan motor rotor is generally made of laminated silicon steel sheets, which has fewer slots than the electromagnetic DC motor rotor. Most of the low-power motors used in recorders have 3 slots, and higher-end motors have 5 or 7 slots.
The enameled wire is wound between the two slots of the rotor core (three slots means three windings), and each of its joints is welded to the metal sheet of the commutator. The brush is a conductive component that connects the power supply and the rotor winding. It has both conductive and wear-resistant properties. The brushes of permanent magnet motors use single metal sheets or metal graphite brushes or electrochemical graphite brushes.
First of all, are you sure the wind is strong enough for the fan to rotate? Then, there is no problem with a larger inverter, but there is no problem with a larger inverter. Then, what is your load? It's definitely not a battery. The power of the battery has nothing to do with the operation of the fan. Try connecting it to a large load. Also, if it still doesn't turn, it means the brake is locked inside, so read the manual. Check if there is any internal structure or anything like that. This problem can also occur if there are brakes and protection. 1000W fans are generally systems with a simple structure. As long as there are no problems with the inverter, they should be fine. Be careful not to short circuit.