The company’s DC971 permanent magnet d.c. motor for hand mixers is constructed with an open frame design. According to the company, the magnets of the motor are held in a steel shell that is open at both ends, which allows for a more effective flow of cooling air through the motor and over the armature. Due to a larger surface area, the motor can radiate heat away from the motor.
Combining the open frame design and the larger thermal mass substantially reduces thermal resistance and increases thermal conductivity.
Johnson Electric Group