摘要:
A permanent magnet electric motor has a stator and a rotor. The stator has a stator housing with at least a North pole and a South pole, each pole including permanent magnets affixed to an inner surface of the stator housing, where at least two of the magnets within a pole have dissimilar characteristics, e.g., different widths or different grades of demagnetization resistance.
摘要:
A permanent magnet electric motor has a stator and a rotor. The stator has a stator housing with at least a North pole and a South pole. Each pole includes at least two permanent magnets arranged on an inner surface of the stator housing near the pole tips and an overmold of magnetic material molded around the permanent magnets and over the inner surface of the stator between the permanent magnets. Alternatively, an overmold of magnetic material may be provided over an inner surface of the stator, where the thickness of the overmold layer is greater near tips of each pole than in the middle portion of each pole.
摘要:
A power tool is provided, including a housing, a permanent magnet electric motor in the housing, and an output member coupled to the electric motor. The electric motor includes a rotor and a stator with at least a North pole and a South pole. The stator includes a lamination stack of identically-shaped magnetically-conductive laminations with the identically-shaped pockets stamped therein and secured together in alignment to form the at least one magnet pocket at each pole. Each magnet pocket is contained within the lamination stack distanced from the inner and outer surfaces of the lamination stack. The stator further including at least one permanent magnet embedded within each magnet pocket of each pole.
摘要:
A power tool is provided, including a housing, a permanent magnet electric motor in the housing, and an output member coupled to the electric motor. The electric motor includes a rotor and a stator with at least a North pole and a South pole. The stator includes a lamination stack having loose laminations held together via an overmolded resin. The overmolded resin include a longitudinal overmold layer covering at least a portion of at least one of an inner or outer surfaces of the lamination stack, and two end cap portions extending laterally from the ends of the longitudinal overmold layer to firmly cover ends of the lamination stack.
摘要:
A power tool is provided, including a housing, a permanent magnet electric motor in the housing, and an output member coupled to the electric motor. The electric motor includes a rotor and a stator. The stator includes a lamination stack of identically-shaped laminations with a North pole and a South pole. The stator also includes an end cap arranged at one end of the lamination stack. The end cap includes a polarity keying feature in an outer surface therein at a predetermined position with respect to one of the North pole or the South pole to identify a polarity of the stator.