As electric vehicles gradually enter the market, the manufacturing requirements for permanent magnet motors are becoming increasingly stringent. I'd like to know, with the development of permanent magnet motors, what specific requirements are placed on the motor housing?
The development trend of electric motors is actually towards higher efficiency and lighter weight. Using permanent magnets is an important means of improving efficiency (their characteristics are another issue); it also reduces weight to some extent. If an aluminum alloy frame and end caps are used, the weight can be reduced significantly. Of course, if better plastics or other materials are developed in the future, achieving both high strength and hardness, as well as high temperature resistance and aging prevention, that will be another technological revolution.
Permanent magnet synchronous motors (PMSMs) are prone to generating significant eddy current and harmonic losses in their permanent magnets and stator/rotor cores, which manifest as heat. This leads to increased overall or localized temperature rise within the motor and can even cause demagnetization of the permanent magnets, severely impacting the motor's performance and reliability. Therefore, PMSMs have stringent heat dissipation requirements. When welding the protective cover to the PMSM housing, these requirements must be fully considered to avoid hindering heat dissipation, as this would negatively affect the motor's performance and reliability.
The motor guard serves two purposes. First, it prevents solids from entering the casing and prevents people from touching dangerous parts inside the casing. Second, it controls airflow. Because the fan is self-cooling, a guard directs the airflow along the gap between the guard and the heatsink (circumferentially distributed) towards end D, thus carrying away heat from the heatsink. Without a guard, the fan airflow is directionless, resulting in extremely poor heat dissipation.
