Encapsulated motor with precision bearing registration
First Claim
1. An encapsulated stator electrical motor comprising, in combination:
- a rotor assembly having a plurality of rotor laminations fixed in a stack on a rotor shaft, rotor bearings on the rotor shaft at either end of the rotor lamination stack, the outer diameter of the bearings being slightly greater than the outer diameter of the rotor lamination stack;
a unitary potted stator assembly including a stator lamination stack with exterior exposed and stator end caps on either end of the stator lamination stack;
a continuous bore formed in the stator assembly through a first one of the end caps, through the stator lamination stack and through a second one of the stator end caps, the bore forming an internal cylindrical area for receipt of the rotor lamination stack and bearing surfaces in the end caps, the bore comprising a smoothly machined surface free of discontinuities capable of trapping machining debris formed during machining of the bore, the smoothly machined surface of the bore exposing portions of the end caps, the stator lamination stack and interposed potting material; and
the rotor assembly being carried within the bore formed in the stator assembly with the rotor bearings engaging the bearing surfaces in the end caps leaving an air gap between the rotor lamination stack and the stator lamination stack.
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Accused Products
Abstract
The rotor of an electrical motor, such as a hybrid permanent magnet stepping motor or a variable reluctance motor is assembled on a rotor shaft, and includes at least one lamination stack and a pair of supporting bearings, with the outer diameter of the bearings being slightly larger than that of the lamination stack. A stator is assembled from a stator lamination stack including a pole configuration and a pair of unmachined end caps registered and secured to the lamination stack such as by thru bolts. The registered stator assembly is potted to unitize the assembly, fixing the relationship between the end caps and the lamination stack, and providing a smooth continuous bore through the center of the stator assembly. The thus potted assembly is machined as by diamond lapping to form a continuous bore accurately machined through the center of the stator, concurrently forming bearing surfaces in the end caps and an intermediate machined section in the lamination stack. The rotor assembly is inserted into the stator assembly, with the machined bore providing bearing mounting surfaces in the end caps and an air gap for rotation of the rotor in the lamination stack.
92 Citations
10 Claims
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1. An encapsulated stator electrical motor comprising, in combination:
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a rotor assembly having a plurality of rotor laminations fixed in a stack on a rotor shaft, rotor bearings on the rotor shaft at either end of the rotor lamination stack, the outer diameter of the bearings being slightly greater than the outer diameter of the rotor lamination stack; a unitary potted stator assembly including a stator lamination stack with exterior exposed and stator end caps on either end of the stator lamination stack; a continuous bore formed in the stator assembly through a first one of the end caps, through the stator lamination stack and through a second one of the stator end caps, the bore forming an internal cylindrical area for receipt of the rotor lamination stack and bearing surfaces in the end caps, the bore comprising a smoothly machined surface free of discontinuities capable of trapping machining debris formed during machining of the bore, the smoothly machined surface of the bore exposing portions of the end caps, the stator lamination stack and interposed potting material; and the rotor assembly being carried within the bore formed in the stator assembly with the rotor bearings engaging the bearing surfaces in the end caps leaving an air gap between the rotor lamination stack and the stator lamination stack. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification