Abstract: A tool such as a string trimmer having an outer-rotor motor is disclosed. The tool includes a motor housing configured to align a rotor assembly, a stator assembly, a bearing support structure that fully pilots and supports the rotor assembly on one side of the motor housing, and a heat sink that fully supports the stator assembly on another side of the motor housing. The heat sink seals the motor housing from debris and is configured to absorb heat generated by the outer-rotor motor without added airflow from a fan or from openings. The disclosed outer-rotor motor requires no adhesives to hold magnets, thereby simplifying fabrication and improving magnet performance.

Abstract: A brushless direct-current (BLDC) motor is provided. The motor includes a stator including a stator core, stator teeth, and windings; a rotor shaft disposed within the stator and extending along a longitudinal axis; and a rotor. The rotor includes a rotor core including a body extending around the longitudinal axis, a permanent magnet mounted on the body of the rotor core, and a mold structure formed at least partially through the rotor core. In an embodiment, the mold structure engages two axial ends of the permanent magnet to axially retain the permanent magnet relative to the rotor core and integrally forms a fan adjacent the rotor core. In an embodiment, the permanent magnet includes at least one tooth extending from an axial end thereof and having angled side edges, and the mold structure engages the at least one tooth to fixedly secure the permanent magnet to the rotor core.

Abstract: A brushless direct-current (BLDC) motor is provided. The motor includes a stator including a stator core, stator teeth, and windings; a rotor shaft disposed within the stator and extending along a longitudinal axis; and a rotor. The rotor includes a rotor core having a cylindrical body, a permanent magnet ring mounted on an outer surface of the cylindrical body with no intermediate adhesive therebetween, and metal sleeve securely fitted outside the permanent magnet ring. The metal sleeve includes a flange extending radially inwardly that covers an axial end of the permanent magnet ring and is bonded to the rotor core to secure the permanent magnet ring to the rotor core.

Abstract: A motor assembly is provided including a stator assembly and a rotor assembly rotatably disposed relative to the stator assembly. The rotor assembly includes a rotor core having magnet pockets formed therethrough along a longitudinal direction, permanent magnets received within the magnet pockets, and a spring structure disposed in contact with the end of the rotor core. The spring structure includes spring elements configured to apply biasing forces to the permanent magnets along the longitudinal direction of the magnet pockets. Optionally a magnet retention end cap is provided to secure the spring structure to the end of the rotor core.

Abstract: A brushless direct-current (BLDC) motor is provided. The motor includes a stator including a stator core, stator teeth, and windings; a rotor shaft disposed within the stator and extending along a longitudinal axis; and a rotor. The rotor includes a rotor core including an inner body mounted on the rotor shaft and radial projections projecting outwardly from the inner body, a permanent magnet mounted on an outer end of the radial projections, and a mold structure formed in contact with the radial projections and configured to secure the permanent magnet to the rotor core.

Abstract: A brushless direct-current (BLDC) motor is provided. The motor includes a stator including a stator core, stator teeth, and windings; a rotor shaft disposed within the stator and extending along a longitudinal axis; and a rotor. The rotor includes a rotor core having a cylindrical body, a permanent magnet ring mounted on an outer surface of the cylindrical body with no intermediate adhesive therebetween, and metal sleeve securely fitted outside the permanent magnet ring. The metal sleeve includes a flange extending radially inwardly that covers an axial end of the permanent magnet ring and is bonded to the rotor core to secure the permanent magnet ring to the rotor core.

Abstract: A brushless direct-current (BLDC) motor is provided. The motor includes a stator including a stator core, stator teeth, and windings; a rotor shaft disposed within the stator and extending along a longitudinal axis; and a rotor. The rotor includes a rotor core including an inner body mounted on the rotor shaft and radial projections projecting outwardly from the inner body, a permanent magnet mounted on an outer end of the radial projections, and a mold structure formed in contact with the radial projections and configured to secure the permanent magnet to the rotor core.

Abstract: A motor assembly is provided including a stator assembly and a rotor assembly rotatably disposed relative to the stator assembly. The rotor assembly includes a rotor core having magnet pockets formed therethrough along a longitudinal direction, permanent magnets received within the magnet pockets, and a spring structure disposed in contact with the end of the rotor core. The spring structure includes spring elements configured to apply biasing forces to the permanent magnets along the longitudinal direction of the magnet pockets. Optionally a magnet retention end cap is provided to secure the spring structure to the end of the rotor core.