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US4503377A Expired / Lapsed US ⏱️ 0.0 years remaining

Variable speed rotary electric machine

Assignee: Hitachi Ltd
•
Filing: 1984-01-04
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Granted: 1985-03-05
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Expires: 2004-01-04
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Abstract

Abstract A variable speed rotary electric machine comprises a stator composed of a stator core and first and second stator windings wound on the stator core, and a cage rotor mounted rotatably within the stator and composed of a rotor core and rotor conductor disposed in a squirrel-cage configuration. The first stator winding is connected to an AC power supply of a fixed frequency. The second stator winding is connected to a power supply of a variable frequency. The first and second stator windings are so wound as to form, respectively, numbers of poles differing from each other. The rotor conductors of the cage rotor are electromagnetically coupled with the magnetic flux generated by the first and second stator windings, respectively, and so disposed as to form a number of poles which is intermediate between the number of the poles formed by the first stator winding and the number of poles formed by said second stator winding.

Inventors

  • 👤 Yukio Kitabayashi
  • 👤 Noriyoshi Takahashi
  • 👤 Masatoshi Watanabe
  • 👤 Toshiaki Okuyama
  • 👤 Yoji Tanaka

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 06:06
CPC Classifications
H; H02; H02K; H02K17/00; H02K17/42; H02P; H02P9/00; H02P9/007; H02P9/48

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 149 words
A variable speed rotary electric machine, comprising a stator having first and second stator windings wound on a stator core and a cage rotor mounted rotatably within said stator and including a rotor core and rotor conductors constituting a cage rotor winding, wherein said first stator winding is connected to an AC power supply of a constant frequency while said second stator winding is connected to a power supply of variable frequency, said first and second stator windings being so wound as to form magnetic poles in numbers differing from each other, the rotor conductors of said cage rotor being electromagnetically coupled with magnetic fluxes generated by said first and second stator windings and so disposed as to form magnetic poles whose number is intermediate between the number of magnetic poles formed by said first stator winding and the number of magnetic poles formed by said second stator winding.
Claim 2
Dependent Claim 149 words
A variable speed rotary electric machine, comprising a stator having first and second stator windings wound on a stator core and a cage rotor mounted rotatably within said stator and including a rotor core and rotor conductors constituting a cage rotor winding, wherein said first stator winding is connected to an AC power supply of a constant frequency while said second stator winding is connected to a power supply of variable frequency, said first and second stator windings being so wound as to form magnetic poles in numbers differing from each other, the rotor conductors of said cage rotor being electromagnetically coupled with magnetic fluxes generated by said first and second stator windings and so disposed as to form magnetic poles whose number is intermediate between the number of magnetic poles formed by said first stator winding and the number of magnetic poles formed by said second stator winding.
Claim 3
Dependent Claim 43 words
A variable speed rotary electric machine according to claim 1, wherein the number of the rotor conductors of said cage rotor is so selected as to correspond to an average of the numbers of poles formed by said first and second stator windings.
Claim 4
Dependent Claim 37 words
A variable speed rotary electric machine according to claim 1, wherein the rotor bars of said cage rotor are realized in a multiple cage structure, the rotor conductors constituting respective cages being electrically independent of one another.
Claim 5
Dependent Claim 173 words
A variable speed rotary electric machine, comprising a stator having first and second stator windings wound on a stator core and a cage rotor mounted rotatably within said stator and including a rotor core and rotor conductors constituting a cage rotor winding, wherein said first stator winding is connected to an AC power supply of a constant frequency and said second stator winding is connected to a power supply of variable frequency, said first and second stator windings being adapted for simultaneous energization by said constant frequency power supply and said variable frequency power supply, respectively, said first and second stator windings being so wound as to form magnetic poles in numbers differing from each other, the rotor conductors of said cage rotor being electromagnetically coupled with magnetic fluxes generated by said first and second stator windings and so disposed as to form magnetic poles whose number is intermediate between the number of magnetic poles formed by said first stator winding and the number of magnetic poles formed by said second stator winding.
Claim 6
Dependent Claim 173 words
A variable speed rotary electric machine, comprising a stator having first and second stator windings wound on a stator core and a cage rotor mounted rotatably within said stator and including a rotor core and rotor conductors constituting a cage rotor winding, wherein said first stator winding is connected to an AC power supply of a constant frequency and said second stator winding is connected to a power supply of variable frequency, said first and second stator windings being adapted for simultaneous energization by said constant frequency power supply and said variable frequency power supply, respectively, said first and second stator windings being so wound as to form magnetic poles in numbers differing from each other, the rotor conductors of said cage rotor being electromagnetically coupled with magnetic fluxes generated by said first and second stator windings and so disposed as to form magnetic poles whose number is intermediate between the number of magnetic poles formed by said first stator winding and the number of magnetic poles formed by said second stator winding.
Claim 7
Dependent Claim 43 words
A variable speed rotary electric machine according to claim 4, wherein the number of the rotor conductors of said cage rotor is so selected as to correspond to an average of the number of poles formed by said first and second stator windings.
Claim 8
Dependent Claim 37 words
A variable speed rotary electric machine according to claim 4, wherein the rotor bars of said cage rotor are realized in a multiple cage structure, the rotor conductors constituting respective cages being electrically independent of one another.
Claim 9
Dependent Claim 29 words
A variable speed rotary electric machine according to claim 4, wherein said stator having said first and second stator windings wound on said stator core is a non-rotatable member.

References Cited (Backward Citations)

US1617394A Cited
US2280456A Cited
US2573283A Cited
US2808552A Cited
US2845588A Cited
US2896143A Cited
US4039910A Cited
US4143309A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-03-04 1988-09-03 1989-03-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-03-04 1992-09-03 1993-03-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-03-04 1996-09-03 1997-03-05 $7700.00 Window Closed / Lapsed

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