Patent US3967170A successfully refreshed from Google Patents.
US3967170A
Expired / Lapsed
US
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Position synchronization of machines
Assignee: Eaton Corp
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Filing: 1974-10-25
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Granted: 1976-06-29
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Expires: 1994-10-25
Abstract
Abstract Apparatus for synchronizing the relative positions of motor-driven machines. Preliminary to operating the machines in synchronism, the rotors of individual synchronous motors that drive the machines are moved to a stop at certain angular positions. The angular positions are such that when inverter voltage is thereafter applied to the stators of all of the motors from a common inverter, the instantaneous angular position of the stator magnetic field with respect to the respective rotor is the same for all of the motors. In one embodiment, several machines are synchronized as to position by first operating each at low speed to a home position. Arrival of each machine at its home position is detected by detecting the simultaneous existence of two signals: (a) a first signal indicating that the instantaneous phase of inverter voltage applied to the stator is within a predetermined range, (b) a second signal indicating that the position of the machine member driven by the respective motor is within a predetermined tolerance range of the home position. Thereupon, if a third signal indicates that the speed of the motor is below a predetermined threshold speed, a brake is applied to hold the machine in its home position. After all of the machines reach their home positions their respective brakes can be released and all motors can be energized from a common inverter in order to operate the machines in positional synchronism.
Inventors
- 👤 Ian M. MacDonald
- 👤 Charles J. Cowie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:05
CPC Classifications
H; H02; H02P; H02P5/00; H02P5/46; H02P5/52
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
197 words
In a system having a plurality of machines each including a synchronous motor with an armature winding for producing a magnetic field and a rotor non-slippably coupled with a respective movable machine member, apparatus for synchronizing the relative positions of the plurality of machines comprising means for detecting when the rotor of each of said motors is in a predetermined angular position relative to its respective armature winding and producing a first signal thereupon and stopping means responsive to occurrence of said first signal of the machine to stop rotation of said rotor proximate said predetermined angular position, said rotor position relative to said respective armature winding being substantially the same for all of said motors, and means for subsequently starting and accelerating all of said machines simultaneously from their predetermined angular positions while maintaining position synchronization of said machines, said starting and accelerating means including means for energizing the armature windings of all of said motors simultaneously all with the same phase of A.C. voltage to maintain an instantaneous angular position of armature magnetic field with respect to said predetermined angular position of the respective rotor that is substantially the same for all of said motors.
Claim 2
Dependent Claim
197 words
In a system having a plurality of machines each including a synchronous motor with an armature winding for producing a magnetic field and a rotor non-slippably coupled with a respective movable machine member, apparatus for synchronizing the relative positions of the plurality of machines comprising means for detecting when the rotor of each of said motors is in a predetermined angular position relative to its respective armature winding and producing a first signal thereupon and stopping means responsive to occurrence of said first signal of the machine to stop rotation of said rotor proximate said predetermined angular position, said rotor position relative to said respective armature winding being substantially the same for all of said motors, and means for subsequently starting and accelerating all of said machines simultaneously from their predetermined angular positions while maintaining position synchronization of said machines, said starting and accelerating means including means for energizing the armature windings of all of said motors simultaneously all with the same phase of A.C. voltage to maintain an instantaneous angular position of armature magnetic field with respect to said predetermined angular position of the respective rotor that is substantially the same for all of said motors.
Claim 3
Dependent Claim
91 words
Apparatus for synchronizing the relative positions of a plurality of machines as defined in claim 1 wherein said means for detecting when the rotor of each of said motors is in a predetermined angular position comprises means for applying ac voltage to the armature winding of a motor not already at said predetermined position and means for detecting when the instantaneous phase of said ac voltage applied to the armature of said motor is approximately at a predetermined phase while said motor is operating before said stopping means stops said rotor.
Claim 4
Dependent Claim
61 words
Apparatus for synchronizing the relative positions of a plurality of machines as defined in claim 2 and wherein said means for applying ac voltage comprises three-phase power source means, and said means for detecting said instantaneous phase comprises means for detecting when two phases of said three-phase power source are of like polarity with respect to neutral potential of said source.
Claim 5
Dependent Claim
65 words
Apparatus for synchronizing the relative positions of a plurality of machines as defined in claim 1 and further comprising means for sensing the speed of said motors and producing a low-speed signal when said speed is below a predetermined threshold, and means responsive to said low-speed signal to enable and disable said stopping means when said speed is below and above said predetermined threshold respectively.
Claim 6
Dependent Claim
70 words
Apparatus for synchronizing the relative positions of a plurality of machines as defined in claim 1 and further comprising apparatus for synchronously increasing the speed of said motors by increasing the frequency of said energizing means after starting all of said machines in synchronism, and means for decreasing said frequency to below a threshold speed in preparation for stopping of all of said machines in synchronism at said predetermined positions.
Claim 7
Dependent Claim
44 words
Apparatus for synchronizing the relative positions of a plurality of machines as defined in claim 1 and wherein said stopping means comprises means for de-energizing the armature windng of the respective motor and for applying a brake to the machine at said predetermined position.
Claim 8
Dependent Claim
35 words
Apparatus for synchronizing the relative positions of a plurality of machines as defined in claim 1 and wherein said means for energizing comprises static inverter means employed in common for energizing all of said motors.
Claim 9
Dependent Claim
85 words
Apparatus for synchronizing the relative positions of a plurality of machines as defined in claim 1 and further comprising means for operating each of said motors at a creep speed to reach said predetermined angular position of the rotor, and wherein each of said motors comprises a motor that rotates with non-uniform velocity in steps when operating at creep speed, and wherein said predetermined angular position of said rotor is a position corresponding to a slower portion of one of said steps of non-uniform velocity.
Claim 10
Dependent Claim
38 words
Apparatus as defined in claim 1 and further comprising means for producing a start command signal, and means responsive to said start command signal for energizing each of said machines to move to their respective predetermined angular positions.
Claim 11
Dependent Claim
69 words
Apparatus for synchronizing the relative positions of a plurality of machines as defined in claim 1 and further comprising means for sensing when the position of the respective movable member is in a predetermined range and producing a second signal thereupon, and wherein said stopping means is responsive to arrival of the machine at a home position as indicated by said first and second signals to stop said machine.
Claim 12
Dependent Claim
74 words
Apparatus for synchronizing the relative positions of a plurality of machines as defined in claim 10 and wherein said means for sensing when the position of the respective movable members is in a predetermined range and producing a second signal comprises a transformer device energized by ac power and arranged so that the magnetic coupling between two windings of said transformer device depends upon the position of said respective movable member of said machine.
Claim 13
Independent Claim
280 words
A method for synchronizing the relative positions of a plurality of machines each having a synchronous motor with an armature winding for producing a magnetic field and a rotor coupled through a non-slip coupling with a respective movable machine member comprising the steps of sensing whether or not the position of the movable member of each machine is within a respective predetermined range and producing a member position signal accordingly, in response to said member position signals, energizing the armature winding of each of those of said motors whose respective movable members are not within respective predetermined ranges, to operate those motors, detecting when the rotor of each of said motors is in a predetermined angular position relative to its respective armature winding and producing a rotor position signal thereupon, said predetermined angular position of each of said rotors relative to its respective armature winding being substantially the same for all of said motors, stopping each of said machines with its rotor proximate said respective predetermined angular position in response to indications by said member position signal and said rotor position signal that said machine is in a home position corresponding to both said predetermined range and said predetermined angular position, detecting when all of said machines are in their respective home positions, and starting and accelerating all of said machines in synchronism by energizing the armature windings of all of said motors simultaneously all with the same phase of A.C. voltage while maintaining position synchronization of said machines to maintain an instantaneous angular position of armature magnetic field with respect to said predetermined angular position of the respective rotor that is substantially the same for all of said motors.
Claim 14
Independent Claim
280 words
A method for synchronizing the relative positions of a plurality of machines each having a synchronous motor with an armature winding for producing a magnetic field and a rotor coupled through a non-slip coupling with a respective movable machine member comprising the steps of sensing whether or not the position of the movable member of each machine is within a respective predetermined range and producing a member position signal accordingly, in response to said member position signals, energizing the armature winding of each of those of said motors whose respective movable members are not within respective predetermined ranges, to operate those motors, detecting when the rotor of each of said motors is in a predetermined angular position relative to its respective armature winding and producing a rotor position signal thereupon, said predetermined angular position of each of said rotors relative to its respective armature winding being substantially the same for all of said motors, stopping each of said machines with its rotor proximate said respective predetermined angular position in response to indications by said member position signal and said rotor position signal that said machine is in a home position corresponding to both said predetermined range and said predetermined angular position, detecting when all of said machines are in their respective home positions, and starting and accelerating all of said machines in synchronism by energizing the armature windings of all of said motors simultaneously all with the same phase of A.C. voltage while maintaining position synchronization of said machines to maintain an instantaneous angular position of armature magnetic field with respect to said predetermined angular position of the respective rotor that is substantially the same for all of said motors.
Claim 15
Dependent Claim
72 words
A method for synchronizing the relative positions of a plurality of machine as defined in claim 12 and wherein said step of energizing the armature winding of each of those of said motors that are not within the range comprises energizing with ac excitation, and said step of detecting when the rotor is in a predetermined angular position sensing when the phase of ac excitation is within a predetermined range of phase.
Claim 16
Dependent Claim
58 words
A method for synchronizing the relative positions of a plurality of machines as defined in claim 12 and further comprising the steps of sensing whether or not the speed of each of said motors is below a predetermined speed threshold, and enabling said step of stopping each of said machines only when said speed is below said threshold.
Claim 17
Dependent Claim
81 words
A method for synchronizing the relative positions of a plurality of machines are defined in claim 12 and further comprising the step after all of said machines are operating in synchronism of sensing when each machine is at a home position by sensing for each machine said signals indicating that the movable member and the rotor thereof are at said predetermined range and predetermined angular position respectively, and stopping all of said machines in synchronism in response to sensing said signals.
Claim 18
Dependent Claim
96 words
A method for synchronizing the relative positions of a plurality of machines as defined in claim 15 and further comprising the steps of automatically accelerating said machines in synchronism subsequent to said step of starting in synchronism, by increasing the frequency of ac voltage by which all of said motors are excited, producing a stop command, automatically decelerating all of said machines in synchronism in response to said stop command by decreasing said frequency, and sensing when the speed is below a predetermined threshold, prerequisite to said step of stopping all of said machines in synchronism.
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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) | 1979-06-29 | 1979-12-29 | 1980-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-29 | 1983-12-29 | 1984-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-29 | 1987-12-29 | 1988-06-29 | $7700.00 | Window Closed / Lapsed |