Motor cooling solution
How to achieve more efficient heat dissipation has always been a key issue in motor design. It is more prominent for the hub motor. In general, in order to reduce costs, the hub motor uses more air cooling. Therefore, the problem is refined into how to improve the cooling capacity of air cooling. Generally, it can be divided into two types: optimizing the existing cooling structure and adopting a new cooling system.
To optimize the existing structure, one method increases the area of the heat dissipation ribs and increases the heat dissipation power.
Another method is to optimize the arrangement direction of the heat dissipation ribs, and adjust the direction to the same direction as the wind speed, and also slightly improve the heat dissipation effect.
The effect of local optimization is limited, and if there is a qualitative improvement in cooling power, a new cooling system is required. A heat pipe cooling technique is described below.
UQM's motors use a heat pipe cooling technology. The copper heat pipes extend axially into the motor casing, quickly transferring heat from the stator to specially designed heat sinks, where ventilation is good. For a 13.7kw motor, the peak cooling power is 1.3kW without forced cooling. If forced cold source (air-cooled) is applied, the peak heat dissipation power can reach 3.7kw.
In practice, this heat pipe cooling technology can significantly reduce the motor temperature. In the case of natural cooling, the temperature of the stator is lowered to 65 ° C and the temperature of the rotor is lowered to 52 ° C. If forced air cooling is used, the temperature can be further reduced.
