Permanent magnet rotor and method and apparatus for making same
First Claim
1. A permanent magnet rotor for use in an electric motor, said rotor comprising, in combination, a core, a plurality of magnetizable elements disposed about a generally fixed diameter cylindrical outer peripheral surface of said core, said magnetizable elements being arcuate in transverse cross-section and having arcuate outer surfaces lying in a common cylindrical envelope, and an outer cup-shaped relatively thin-walled metallic shell having an annular wall terminating at one end in a substantially closed end wall and having a peripheral edge defining an opposite open end, said core and magnetizable elements being disposed within said shell, said annular wall having an inner diameter to create an interference fit with said magnetizable elements when said core and elements are inserted into said shell, and an end plate within said open end of said shell opposite corresponding ends of said core and magnetizable elements, said peripheral edge of said shell being formed to overlie said end plate and retain said core and magnetizable elements in encapsulated relation within said shell.
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Accused Products
Abstract
A permanent magnet rotor includes a core and a plurality of magnetizable elements adhesively secured to the outer surface of the core. The core and adhered magnetizable elements are cold-pressed into a deep drawn cup-shaped outer metallic shell having a substantially closed end wall and an opposite open end defined by a peripheral edge which is rolled over the periphery of an end plate to encapsulate the core and magnetizable elements within the shell with an insulator disk disposed between each end of the core and the adjacent shell end wall and end plate. A method and apparatus for cold pressing the core and magnetizable elements into the cup-shaped shell and forming the peripheral edge of the shell over the end plate to effect encapsulation are also disclosed.
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Citations
22 Claims
- 1. A permanent magnet rotor for use in an electric motor, said rotor comprising, in combination, a core, a plurality of magnetizable elements disposed about a generally fixed diameter cylindrical outer peripheral surface of said core, said magnetizable elements being arcuate in transverse cross-section and having arcuate outer surfaces lying in a common cylindrical envelope, and an outer cup-shaped relatively thin-walled metallic shell having an annular wall terminating at one end in a substantially closed end wall and having a peripheral edge defining an opposite open end, said core and magnetizable elements being disposed within said shell, said annular wall having an inner diameter to create an interference fit with said magnetizable elements when said core and elements are inserted into said shell, and an end plate within said open end of said shell opposite corresponding ends of said core and magnetizable elements, said peripheral edge of said shell being formed to overlie said end plate and retain said core and magnetizable elements in encapsulated relation within said shell.
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10. A permanent magnet rotor for use in an electric motor, said rotor comprising, in combination, a core, a plurality of magnetizable elements disposed about a generally cylindrical outer peripheral surface of said core, said magnetizable elements being arcuate in transverse cross-section and having arcuate outer surfaces lying in a common cylindrical envelope, and an outer cup-shaped metallic shell having an annular wall terminating at one end in a substantially closed end wall and having a peripheral edge defining an opposite open end, said core and magnetizable elements being disposed within said shell, an end plate within said open end of said shell opposite corresponding ends of said core and magnetizable elements, a first substantially electrically nonconducting insulating disk disposed within said shell between said closed end wall and adjacent ends of said core and magnetizable elements, a second substantially electrically nonconducting insulating disk disposed between the opposite ends of said core and magnetizable elements and said end plate, said peripheral edge of said shell being formed to overlie said end plate and retain said core and magnetizable elements in encapsulated relation within said shell, said core having an axial bore formed therethrough, said closed end of said shell having a central aperture therethrough, and said end plate and first and second insulating disks having annular configurations so as to expose opposite ends of said axial bore.
- 11. A permanent magnet rotor for use in an electric motor and comprising a plurality of arcuate magnetizable segments secured to an outer substantially cylindrical surface of a core, said core and magnetizable segments having generally equal longitudinal lengths and being disposed within a metallic cup-shaped shell having an annular wall surrounding said magnetizable segments in a press fit therewith, said shell having a substantially closed end wall defining one end thereof and having a peripheral edge defining an opposite open end thereof, a metallic end plate disposed within said open end of said cup, said peripheral edge being formed to create a lip over said end plate to encapsulate said core and magnetizable segments within said shell between said closed end and said end plate.
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17. Apparatus for making a permanent magnet rotor which includes a core having a plurality of magnetizable elements adhered to an outer peripheral surface of the core with the magnetizable elements having outer surfaces lying in a cylindrical envelope, and a cup-shaped metallic shell having an annular wall terminating at one end in a generally closed end wall and having an open opposite end defined by a peripheral edge, said apparatus comprising, in combination,
stripper plate means defining a generally cylindrical recess adapted to have a cup-shaped shell inserted therein with its open end exposed, press shaft means disposed within said recess in a manner enabling relative movement between said stripper plate means and said press shaft means, said press shaft means defining a support end enabling placement of the closed end of a cup-shaped shell thereon when inserted into said recess with the open end of the shell oriented to have a core and adhered magnetizable elements placed on the shell in axial alignment with said open end, and press plate means operative to cold-press the core and adhered magnetizable elements into the shell while simultaneously effecting progressive release of the shell from said recess as the core and magnetizable elements enter the shell.
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22. Apparatus for use in making a permanent magnet rotor which includes a cup-shaped shell having an annular wall terminating at one end in a generally closed end wall and having an open opposite end defined by a peripheral edge, a core having a plurality of magnetizable elements adhered to an outer peripheral surface of the core with the magnetizable elements having outer surfaces lying in a generally cylindrical envelope, said core and magnetizable elements being disposed within said shell so that the peripheral edge of the shell extends outwardly from the core and elements, and an end plate within the open end of the shell and overlying the core and magnetizable elements, said apparatus comprising, in combination,
rotatable support means defining a generally horizontal rotor support surface adapted to support a rotor thereon with the peripheral edge of the shell exposed, clamp means operative to clamp the rotor to said support surface while maintaining said peripheral edge exposed, means for effecting rotation of said support means so that the rotor rotates about a longitudinal axis of the shell, and forming means movable from a non-operating position spaced from the rotor to an operating position to roll the exposed peripheral edge of the shell over the periphery of the end plate to encapsulate the core and magnetizable elements within the shell.
Specification