Dynamoelectric machines including metal filled glass cloth slot closure wedges, and methods of making the same
First Claim
1. A high permeability slot wedge material for use as a slot wedge in a dynamoelectric machine in the form of an elongated bar of uniform cross-sectional configuration along the length thereof, the material comprising an electrically insulating ferromagnetic material comprising approximately by weight:
- from 60% to 80% relatively small ferromagnetic particles;
about 10% reinforcing woven fiberglass fabric; and
from 10% to 20% cross-linked thermosetting polyester resin binder uniformly distributed throughout the wedge material.
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Accused Products
Abstract
A high permeability slot wedge for a dynamoelectric machine with the wedge configured as an elongated bar of uniform cross-sectional configuration formed of a ferromagnetic material having modestly good electrically insulative properties comprising approximately by weight 60% to 80% relatively small ferromagnetic particles such as powdered iron, about 10% reinforcing glass fabric; and 15% to 20% unsaturated thermosetting plastic resin binder such as a polyester resin is disclosed. The ferromagnetic material is homogeneously distributed throughout the thermosetting plastic binder so that the permeability and resistivity of the resulting wedge is substantially uniform throughout.
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Citations
21 Claims
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1. A high permeability slot wedge material for use as a slot wedge in a dynamoelectric machine in the form of an elongated bar of uniform cross-sectional configuration along the length thereof, the material comprising an electrically insulating ferromagnetic material comprising approximately by weight:
- from 60% to 80% relatively small ferromagnetic particles;
about 10% reinforcing woven fiberglass fabric; and
from 10% to 20% cross-linked thermosetting polyester resin binder uniformly distributed throughout the wedge material. - View Dependent Claims (2)
- from 60% to 80% relatively small ferromagnetic particles;
- 3. A wound dynamoelectric machine core having a plurality of slots for receiving portions of electrical coils, access openings int he core for facilitating placement of electrical coil portions in the slots, and magnetically conducting, electrically insulating composite slot closing wedges for closing the access openings subsequent to placement of the coil portions in the slots, each of said slot closing wedges being of substantially uniform electrical resistivity throughout the wedge, the electrical resistivity being at least two ohm-centimeters, and each of said slot closing wedges being of substantially uniform relative magnetic permeability throughout the wedge, the relative magnetic permeability being in the range of about 3 to 5.
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8. A dynamoelectric machine comprising:
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a wound dynamoelectric machine stator core having a generally right circular cylindrical rotor receiving bore, a plurality of slots for receiving portions of electrical coils, and access openings in the core where the slots communicate with the bore for facilitating placement of electrical coil portions in the slots, a dynamoelectric machine rotor journalled for rotation centrally within the bore, the electrical coils, when energized, creating a magnetic field between the stator and the rotor, and magnetically conducting, electrically insulating composite slot closing wedges each comprising an elongated bar of uniform cross-sectional configuration along the length thereof for closing the access openings subsequent to placement of the coil portions in the slots, each of said slot closing wedges being formed from an electrically insulative ferromagnetic material including by weight, from 60% to 80% relatively small ferromagnetic particles, about 10% reinforcing woven fiberglass fabric, and from 10% to 20% cross-linked thermosetting polyester resin binder, each of said slot closing wedges being of substantially uniform relative magnetic permeability throughout the wedge, the slot closing wedges functioning to close the access openings and to enhance the uniformity of the magnetic field between the stator and the rotor. - View Dependent Claims (9, 10, 11)
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12. An insulating slot closing wedge for a dynamoelectric machine made according to the method comprising:
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mixing a powdered ferromagnetic material and an uncured polyester resin to form a paste with the ferromagnetic material forming at least 75% of the paste by weight; impregnating a carrier fabric with the paste; compression molding the impregnated carrier fabric to form a sheet and to polymerize the resin, the resulting formed and polymerized sheet having a relative permeability in the range of 3 to 5; and machining the formed and polymerized sheet to transform the sheet into an elongated bar having a generally uniform cross-sectional configuration along the length thereof. - View Dependent Claims (13, 14, 15)
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16. A homogeneous and machinable stator bore wedge made according to the method comprising:
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mixing a powdered ferromagnetic material with an uncured thermosetting plastic resin to form a paste; impregnating a carrier fabric with the paste the impregnated carrier fabric comprising about 10% to 20% thermosetting plastic resin by weight; compression molding the impregnated carrier fabric to form a slab and to polymerize the resin; and machining the formed and polymerized slab to transform the slab into an elongated bore wedge having a generally uniform cross-sectional configuration along the length thereof. - View Dependent Claims (17, 18, 19)
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20. A high permeability slot wedge for a dynamoelectric machine comprising an elongated bar of uniform cross-sectional configuration along the length thereof and formed from an electrically insulative ferromagnetic material comprising approximately by weight:
- at least 60% relatively small ferromagnetic particles;
about 10% reinforcing woven fiberglass fabric; and
at most 20% cross-linked thermosetting polyester resin binder uniformly distributed throughout the wedge, said slot wedge being of substantially uniform electrical resistivity throughout the wedge and of substantially uniform relative magnetic permeability throughout the wedge, the relative magnetic permeability being in the range of about 3 to 5.
- at least 60% relatively small ferromagnetic particles;
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21. A high permeability slot wedge material for use as an elongated slot wedge of uniform cross-sectional configuration in a dynamoelectric machine, the material formed from an electrically insulative ferromagnetic material comprising approximately by weight:
- at least 60% relatively small ferromagnetic particles;
about 10% reinforcing woven fiberglass fabric; and
at most 20% cross-linked thermosetting polyester resin binder uniformly distributed throughout the material, said material being of substantially uniform electrical resistivity throughout the material and of substantially uniform relative magnetic permeability being in the range of about 3 to 5.
- at least 60% relatively small ferromagnetic particles;
Specification