US4028574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synchronous motor structure incorporating rotor having solid poles
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1975-03-20
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Granted: 1977-06-07
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Expires: 1995-03-20
Abstract
Abstract A synchronous motor incorporates a rotor structure having solid poles. In order to improve the starting characteristic of the motor and protect the pole claws against burning, conductive bars are arranged at each side of the pole below the pole shoe and are electrically connected with the pole to form a quadrature-winding which provides a conductive path for currents induced at the pole surfaces by the time-variable quadrature-field and causes such currents to close around the quadrature-field thereby eliminating current from pole-to-pole by way of the claws. The quadrature-winding also forms a circuit parallel to the solid pole surfaces which thereby improves the asynchronous torque characteristics at low slip rates and reduces the oscillating torque.
Inventors
- 👤 Muzaffer Canay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:45
CPC Classifications
H; H02; H02K; H02K19/00; H02K19/02; H02K19/14; H02K3/00; H02K3/04; H02K3/18; H02K3/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
179 words
A synchronous motor structure having a rotor component comprising a longitudinally extending central body portion, a plurality of solid poles extending outwardly from said body portion, each said pole including a shank terminating at its inner end in a claw connection by means of which said pole is secured to said central body portion and a pole shoe located at its outer end, conductor rods extending respectively in a longitudinal direction along opposite sides of said pole below said pole shoe from one end of the pole to the other and thence across opposite ends of the pole towards the center, said conductor rods together with the surface portion of said pole shoe forming single turn quadrature windings providing closed loop conductive paths confined to the pole for currents induced along the pole surface by the time-variable quadrature-field and which causes said currents to close around the quadrature-field, said quadrature windings also forming circuits parallel to the surfaces of said pole which thereby improves the asynchronous torque of the motor at low slip rates and reduces the oscillating torque.
Claim 2
Dependent Claim
179 words
A synchronous motor structure having a rotor component comprising a longitudinally extending central body portion, a plurality of solid poles extending outwardly from said body portion, each said pole including a shank terminating at its inner end in a claw connection by means of which said pole is secured to said central body portion and a pole shoe located at its outer end, conductor rods extending respectively in a longitudinal direction along opposite sides of said pole below said pole shoe from one end of the pole to the other and thence across opposite ends of the pole towards the center, said conductor rods together with the surface portion of said pole shoe forming single turn quadrature windings providing closed loop conductive paths confined to the pole for currents induced along the pole surface by the time-variable quadrature-field and which causes said currents to close around the quadrature-field, said quadrature windings also forming circuits parallel to the surfaces of said pole which thereby improves the asynchronous torque of the motor at low slip rates and reduces the oscillating torque.
Claim 3
Dependent Claim
37 words
A synchronous motor structure as defined in claim 1 wherein said conductor rods extending longitudinally along opposite sides of said pole below said pole shoe lie in direct contact with the under face of said pole shoe.
Claim 4
Dependent Claim
17 words
A synchronous motor structure as defined in claim 2 wherein said conductor rods have a rectangular profile.
Claim 5
Dependent Claim
17 words
A synchronous motor structure as defined in claim 2 wherein said conductor rods have an L-shaped profile.
Claim 6
Dependent Claim
35 words
A synchronous motor structure as defined in claim 1 wherein said conductor rods extending longitudinally along opposite sides of said pole below said pole shoe lie in direct contact with the sides of said shank.
Claim 7
Dependent Claim
210 words
A synchronous motor structure having a rotor component comprising a longitudinally extending central body portion, a plurality of solid poles extending outwardly from said body portion, each said pole including a shank terminating at its inner end in a claw connection by means of which said pole is secured to said central body portion and a pole shoe located at its outer end, side conductor rods extending respectively in a longitudinal direction along opposite sides of said pole below said pole shoe from one end of the pole to the other and thence across opposite ends of the pole towards the center, conductor rods means extending longitudinally of said pole and which are disposed in a longitudinally extending groove provided in the outer face of said pole shoe, said conductor rod means being connected to the opposite ends of said side conductor rods thus forming single turn quadrature windings providing closed loop conductive paths confined to the pole for currents induced along the pole surface by the time-variable quadrature-field and which causes said currents to close around the quadrature-field, said quadrature windings also forming circuits parallel to the surfaces of said pole which thereby improves the synchronous torque of the motor at low slip rates and reduces the oscillating torque.
Claim 8
Dependent Claim
210 words
A synchronous motor structure having a rotor component comprising a longitudinally extending central body portion, a plurality of solid poles extending outwardly from said body portion, each said pole including a shank terminating at its inner end in a claw connection by means of which said pole is secured to said central body portion and a pole shoe located at its outer end, side conductor rods extending respectively in a longitudinal direction along opposite sides of said pole below said pole shoe from one end of the pole to the other and thence across opposite ends of the pole towards the center, conductor rods means extending longitudinally of said pole and which are disposed in a longitudinally extending groove provided in the outer face of said pole shoe, said conductor rod means being connected to the opposite ends of said side conductor rods thus forming single turn quadrature windings providing closed loop conductive paths confined to the pole for currents induced along the pole surface by the time-variable quadrature-field and which causes said currents to close around the quadrature-field, said quadrature windings also forming circuits parallel to the surfaces of said pole which thereby improves the synchronous torque of the motor at low slip rates and reduces the oscillating torque.
Claim 9
Dependent Claim
32 words
A synchronous motor structure as defined in claim 6 wherein said longitudinally extending groove in the outer face of said pole shoe and said conductor rod means disposed therein have rectangular profiles.
Claim 10
Dependent Claim
31 words
A synchronous motor structure as defined in claim 6 wherein said longitudinally extending groove in the outer face of said pole and said conductor rod means disposed therein have circular profiles.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-06 | 1980-12-06 | 1981-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-06 | 1984-12-06 | 1985-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-06 | 1988-12-06 | 1989-06-07 | $7700.00 | Window Closed / Lapsed |