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US3916273A Expired / Lapsed US ⏱️ 0.0 years remaining

Electric machine having poles switchable for operation at frequencies of 50 Hz and 60 Hz

Assignee: Siemens AG
•
Filing: 1974-12-05
•
Granted: 1975-10-28
•
Expires: 1994-12-05
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Abstract

Abstract An electrical synchronous machine having a slotted stator and having a rotor equipped with salient poles which are adjustable in number to enable the machine to operate at 50 and 60 Hz is equipped with an improved stator winding. The number of poles for each of these frequencies defines a corresponding pole pitch. The improved stator winding is a switchable stator winding having a plurality of coils arranged in the slots of the stator so as to be two coil sides deep thereby defining a two-layer symmetrical three-phase winding wherein the number of slots per pole per phase, q, is given by: WHERE THE NUMERATOR, Z, IS SELECTED SO AS TO BE DIVIDABLE BY 6 WITHOUT REMAINDER FOR 50 Hz operation and by 5 without remainder for 60 Hz operation, and wherein at least one of the following conditions is satisfied: A. THE NUMBER OF SLOTS PER POLE APPROXIMATES 10 FOR 60 Hz operations and 12 for 50 Hz operations; and, B. APPROXIMATES 5 FOR 60 Hz operations and 6 for 50 Hz operation. The stator winding has winding heads at each end of the machine and each of the winding heads is made up of conductor rods having an inclination defining a winding pitch corresponding to the mean value of the pole pitch for 50 Hz operation and the pole pitch for 60 Hz operation. Each of the slots contains an upper conductor rod and a lower conductor rod defining the coil sides disposed therein, the upper conductor rods being respectively connected to the lower conductor rods, at least at one end of the machine, so as to deviate from the winding pitch corresponding to the above-mentioned inclination by at least one slot pitch.

Inventors

  • 👤 Werner Leistner

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 00:37
CPC Classifications
H; H02; H02K; H02K3/00; H02K3/04; H02K3/28; H02K1/00; H02K1/06; H02K1/22; H02K1/28; H02K19/00; H02K19/16; H02K19/26; H02K19/32

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 157 words
In an electrical synchronous machine having a slotted stator and having a rotor equipped with salient poles which are adjustable in number to enable the machine to operate at 50 and 60 Hz, the number of poles for each of said frequencies defining a corresponding pole pitch, the rotor periphery defining a space of sufficient size to accommodate thereon the excitation poles corresponding to the larger number of poles, the excitation poles being configured for the excitation current and the magnetic flux required for the smaller number of poles, attachment means for securing the excitation poles to the rotor in a symmetrical arrangement for each number of the poles, wherein the improvement comprises: a switchable stator winding having a plurality of coils arranged in the slots of the stator so as to be two coil sides deep thereby defining a two-layer symmetrical three-phase winding wherein the number of slots per pole per phase, q, is given by:
Claim 2
Dependent Claim 157 words
In an electrical synchronous machine having a slotted stator and having a rotor equipped with salient poles which are adjustable in number to enable the machine to operate at 50 and 60 Hz, the number of poles for each of said frequencies defining a corresponding pole pitch, the rotor periphery defining a space of sufficient size to accommodate thereon the excitation poles corresponding to the larger number of poles, the excitation poles being configured for the excitation current and the magnetic flux required for the smaller number of poles, attachment means for securing the excitation poles to the rotor in a symmetrical arrangement for each number of the poles, wherein the improvement comprises: a switchable stator winding having a plurality of coils arranged in the slots of the stator so as to be two coil sides deep thereby defining a two-layer symmetrical three-phase winding wherein the number of slots per pole per phase, q, is given by:
Claim 3
Dependent Claim 32 words
The improvement of claim 1, said attachment means comprising slots formed in the rim of the rotor for mounting the excitation poles therein to achieve said symmetrical arrangement of the excitation poles.
Claim 4
Dependent Claim 51 words
The improvement of claim 2 for 60 Hz operation, the winding pitch determined by the connections between said upper conductor bars and said lower conductor bars being shortened by at least one slot pitch compared to said winding pitch corresponding to said inclination of said conductor rods in said winding heads.
Claim 5
Dependent Claim 62 words
The improvement of claim 3 wherein the rotor includes a lamination chain made up of overlapped laminated metal sheets whereon the excitation poles are attached, and wherein the improvement further comprises said slots of the rotor being uniformly distributed about the outer peripheral surface of the laminated chain such that six slots are provided per pole pitch corresponding to 50 Hz operation.
Claim 6
Dependent Claim 62 words
The improvement of claim 2 wherein the rotor includes a lamination chain made up of overlapped laminated metal sheets whereon the excitation poles are attached, and wherein the improvement further comprises said slots of the rotor being uniformly distributed about the outer peripheral surface Of the laminated chain such that six slots are provided per pole pitch corresponding to 50 Hz operation.

References Cited (Backward Citations)

US3140637A Cited
US3419905A Cited
US3611084A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-10-27 1979-04-28 1979-10-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-10-27 1983-04-28 1983-10-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-10-27 1987-04-28 1987-10-28 $7700.00 Window Closed / Lapsed

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