摘要 |
A brushless direct current motor for use in a HVAC system, has a stator and a rotor rotatably mounted to the stator. The stator has a stator core, field windings wound on the stator core and a bushing. The rotor has a shaft rotatably supported by the bushing and adapted to connect with a valve adjuster of the HVAC system. The rotor also has at least one permanent magnet fixed with respect to the shaft. The bushing is a monolithic construction with two journal portions and one middle portion. The two journal portions support the shaft and are formed at respective axial ends of the middle portion. The middle portion has an inner diameter larger than an outer diameter of the shaft at portions corresponding to the middle portion, so as to form a gap between the middle portion and the shaft. |