Device for the electric low-voltage driving of a rotatable mass having high inertia and a motor which is part of said device
First Claim
1. An electric dc motor for driving a rotatable mass having a high inertia, comprising:
- (a) an electric motor having an armature (11) and a field system (13), said field system comprising at least two pole pieces (18) each including one permanent magnet (14) and one excitation coil (16), each magnet providing a first source of magetic energy and each excitation coil providing a second source of magnetic energy,(b) each excitation coil and its associated magnet being disposed one above the other between a yoke (19) and an axis of the motor such that both the first and second sources of magnetic energy produce a resultant magnetic energy which simultaneously acts on a same portion of the armature,(c) each excitation coil having an electric conductor wound around an associated pole piece and along surfaces parallel to an adjacent portion of the yoke to create a magnetic induction in a direction opposed to the direction of the magnetic induction of its associated magnet,(d) means for producing a unidirectional field current in said excitation coils, and(e) electrical energy converter means for supplying electrical power to said armature such that an increase in the magnitude of said unidirectional current progressively decreases the torque coefficient of the motor which is maximum when said coils are not supplied with current.
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Accused Products
Abstract
An electric device for driving a rotatable mass having a high inertia, said device comprising an electric motor supplied with power by a low-voltage dc source through an electronic energy converter supplying power to the armature (11) of the motor; the field system of the motor (12) comprises magnets (14) and excitation coils (16), the electric conductor of a coil being wound around its pole piece (18) along surfaces parallel to the corresponding yoke portion (19); this device further comprises an electronic system for regulating the current in the coils (16) and capable of maintaining during accelerations and decelerations a maximum output voltage of the converter within a wide range of speeds and therefore a maximum power; the increase in the intensity of the current in the coils (16) progressively decreases the torque coefficient of the motor which is maximum when the coils (16) are not supplied with power.
58 Citations
14 Claims
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1. An electric dc motor for driving a rotatable mass having a high inertia, comprising:
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(a) an electric motor having an armature (11) and a field system (13), said field system comprising at least two pole pieces (18) each including one permanent magnet (14) and one excitation coil (16), each magnet providing a first source of magetic energy and each excitation coil providing a second source of magnetic energy, (b) each excitation coil and its associated magnet being disposed one above the other between a yoke (19) and an axis of the motor such that both the first and second sources of magnetic energy produce a resultant magnetic energy which simultaneously acts on a same portion of the armature, (c) each excitation coil having an electric conductor wound around an associated pole piece and along surfaces parallel to an adjacent portion of the yoke to create a magnetic induction in a direction opposed to the direction of the magnetic induction of its associated magnet, (d) means for producing a unidirectional field current in said excitation coils, and (e) electrical energy converter means for supplying electrical power to said armature such that an increase in the magnitude of said unidirectional current progressively decreases the torque coefficient of the motor which is maximum when said coils are not supplied with current. - View Dependent Claims (2, 3)
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4. An electrically controlled device for driving a rotatab1e mass having a high inertia, comprising:
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an electric motor having an armature and a field system, said field system comprising at least one permanent magnet providing a first source of magnetic energy and at least one excitation coil providing a second source of magnetic energy, and means for positioning said first and second sources in said motor such that magnetic energy produced thereby simultaneously acts on a same portion of the armature; electrical energy converter means for supplying electrical power to said armature; and field system control circuit means for controlling the current in said at least one excitation coil, said field system control circuit means including means for supplying a unidirectional field current to said at least one excitation coil having direction which produces magnetic energy which opposes the magnetic energy produced by said first magnetic energy source, and means, responsive to armature voltage and current, for controlling the magnitude of said unidirectional current to maintain the output voltage of said converter at a maximum value over a wide range of speeds during periods of acceleration and deceleration, an increase in the magnitude of said unidrectional current progressively decreasing the torque coefficient of the motor which is maximum when said coil is not supplied with current, wherein said field system control circuit comprises; first servo-control means (A) responsive to changes in armature current for controlling the field current and thereby the motor torque coefficient to maintain the current in the armature at a predetermined maximum value; second servo-control means (B) responsive to changes in the armature voltage for controlling thefield current and thereby the motor torque coefficient to maintain the voltage of the armature at a predetermined maximum value; and a comparison means (C) for comparing the speed of rotation of the rotatable mass with a reference speed and for maintaining the field current at zero value when the mass rotation speed is below said reference value irrespective of the value of the armature current to thereby maintain the motor torque coefficient at its maximum value at mass rotation speeds below said reference speed. - View Dependent Claims (5, 6, 8, 9, 10, 11, 12)
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7. A device according to cliam 5, wherein said magnets are made from a samarium-cobalt alloy.
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13. An electrically controlled device for driving a rotatable mass having a high inertia, comprising:
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an electric motor having an armature and a field system, said field system comprising at least one permanent magnet providing a first source of magnetic energy and at least one excitation coil providing a second source of magnetic energy, and means for positioning said first and secnod sources in said motor such that magnetic energy produced thereby simultaneously acts on a same portion of the armature; electrical energy converter means for supplying electrical power to said armature; and field system control circuit means for controlling the current in said at least one excitation coil, said field system control circuit means including means for supplying a unidirectinal field current to said at least one excitation coil having a direction which produces magnetic energy which opposes the magnetic energy produced by said first magnetic energy source, and means, responsive to armature voltage and current, for controlling the magnitude of said unidirectional current to maintain the output voltage of said converter at a maximum value over a wide range of speeds during periods of acceleration and deceleration, an increase in the magnitude of said unidirectional current progressively decreasing the torque coefficient of the motor which is maximum when said coil is not supplied with current, further comprising means for detecting the speed of the motor, an electronic divider for calculating Emax /ω
, Emax being the maximum counter electromotive force imposed on the motor, and calculator means for calculating the intensity of the field current ##EQU8## in which a and b are the constants of construction of the motor, the value of i thus calculated representing the intensity of the current sent to the coils of the field system so as to obtain a torque coefficient which is such that the output voltage of the converter is maximum.
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14. An electrically controlled device for driving a rotatable mass having a high inertia, comprising:
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(a) an electric motor having an armature (11) and a field system (13), said field system comprising at least two pole pieces (18) each including one permanent magnet (14) and one excitation coil (16), each magnet providing a first source of magnetic energy and each excitation coil providing a second source of magnetic energy, (b) each excitation coil and its associated magnet being disposed one above the other between a yoke (19) and an axis of the motor such that both the first and second sources of magnetic energy produce a resultant magnetic energy which simultaneously acts on a same portion of the armature, (c) each excitation coil having an electric conductor wound around an associated pole piece and along surfaces parallel to an adjacent portion of the yoke to create a magnetic induction in a direction opposite to the direction of the magnetic induction of its associated magnet, (d) means for producing a unidirectional field current in said excitation coils, (e) electrical energy converter means for supplying electrical power to said armature, and (f) field system control circuit means, including said means for producing a unidirectional field current in said excitation coils, for controlling the magnitude of said unidirectional current, in response to the armature voltage and current, to maintian the output of said converter means at a predetermined value over a wide range of speeds during periods of both acceleration and deceleration, an increase in the magnitude of said unidirectional current progressively decreasing the torque coefficient of the motor which is maximum when said coils are not supplied with current.
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Specification