US1553409A - Speed-regulator system - Google Patents

Description

Sept. 15, 1925.

S. A. STAEGE SPEED REGULATOR SYSTEM Filed Feb,

u e a R N a 0 w f T w m .m m 2 mm Sept. 15, 1925 s. A. STAEGE SPEED REGULATOR SYSTEM 2 Sheets-Sheet 2 FiledFem 1921 IIH 4 INVENTOR Stephen ,4, Sfae e ATTORNEY Patented Sept. 1925. l l

UNITED STATES PATENT o FIcE.

s'rEPnEN A. s'rAEeE, or rrrrsnuaen, PENNSYLVANIA, AssIgNoE. 'ro WESTINGHOUSE ELEc'raIc & MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA.

SPEED-REGULATOR SYSTEM.

To all whom it may concern:

Be it known that I, STEPHEN A. STAEGE, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Speed-Regulator Systems, of which the following is a specification.

My invention relates to speed-regulator systems and it has special relation to a sys tem adapted to maintain a constant-speed ratio between a plurality ofv moving members.

. One object of my invention is to provide a speed-regulatorsysten1 of the above-indicated character which shall be simple and efiicient in operation and free from hunting action, at the same time permitting variations in the speeds of either the individual members or the group of members, as an entirety.

In my copending applications, Serial Nos. 350,846 and 327,992, filed Jan. 12, 1920, and Oct. 2, 1919, respectively, are described speed-regulator systems of the above-indicated character, wherein each set of rotating members is propelled by a variable-speed motor. speed-changing device which, in turn, operates a frequency changer that is electrically connected to one winding of an electric differential. The other winding of this electric differential is connected to a reference frequency changer which is common to all of the rotating members. Any difference in frequency between the reference .frequency changer and the individual frequency changer driven by the rotatingmember will cause a corresponding movement of the electric differential to set in motion a train of mechanism adapted to correct the propelling-motor speed in accordance with the abnormal load thereupon.

. In order to obviate the so-called hunting v action of the auxiliary frequenc changer, an anti-hunting device is provide upon the shaft thereof. Inasmuch as it sometimes becomes neccxa-ry to quickly correct the prop'elling-motor speed to meet sudden abnormal loads, the anti-hunting device should be so adapted as not to interfere with the then necessary quick correction.

It is in these latter particulars that the herein described improvements reside, which,

Each rotating member operates a.

ucatitn filed February 14, 1921. "serial No. 444,906.

in the present embodiment, comprise an inertia-responsive accelerating and anti-hunt- Fig. 5 is a detail view illustrating the connection between the coils 31 and 32 and the lever arm 33.

Referring to Fig. 1 of the drawing, the present invention is illustrated as applied to a plurality of rotating rolls but, inasmuch as the devices for all rolls are alike, they will be described with reference to one roll only, and the duplicated parts for the other rolls will be given the same reference numerals. A

A roll 11 is driven by a motor, 12, preferably a shunt-wound motor having a shunt field 13, througha chain of gears 14. Any suitable speed-changing device, such as shown at 15, and illustrated as driven through gear mechanism 16 from the shaft of the roll 11, may be used to change the s eed of the individual rolls, as. desired.

e portion of the speed'changer 15 drives a frequency changer 17, the secondary winding of which is directly connected to the secondary winding 18 of an electric differential. The primary winding 19 of the electric dif ferential is in circuit with a frequency changer 21that is adapted to be driven by a small motor 22. Frequenc changer 21 is common to all of the sets 0 rolls and supplies a substantially constant frequenc to the primary winding 19 of each auxiliary frequency changer.

It is well known that, so long as the frequencies in the primary winding 19 and the secondary winding 18 of the electric differential are the same, there will be no rotation of the shaft 23 thereof. However, when the frequency in the secondary winding 18 varies from that in the primary winding 19, the shaft .23 will be rotated in a direction according to the difference in the two frequencies. That is, if the frequency in the secondary winding is higher than that in the primary winding, the shaft will be rotated in one direction, and, if it is lower than that in the primary winding 19, the shaft will be rotated in the opposite direction. This rotation of the shaft 23 is utilized to operate corrective mechanism that is adapted to correct the strength and speed of the propelling motor 12 to meet the abnormal load conditions upon the rolls.

The shunt field winding 13 of the propelling motor has a motor-operated rheostat 24 in circuit therewith, the arm 25 of which is adapted to be moved in accordance with the rotation of a pilot motor 26, through gear mechanism 27 in the customary manner. Motor 26 has differentially-related windings 28 and 29 which may be alternately energized in the manner about to be described. Connected in parallel circuit relation to the motor 26 are coils 31 and 32 of associated electromagnets which are adapted to normally effect the step-by-step movement of the rheostat arm 25 in the same manner as described in my above-mentioned application, Serial No. 350,846, with reference to magnets 110 and 116, shown in Fig. 5 there of, and the associated mechanism. Inasmuch as this operation is well understood and constitutes no particular part of the present invention, no detailed reference will be made thereto.

Frictionally mounted upon the shaft 23 of the electric differential or differential relay, is a double-acting lever 33, carrying contact arms 34 and 35. Mounted upon the contact arms 34 are discs or contactors 36 and 37, res ectively adapted to bridge terminals 38 ant 39. Arm 35 carries contactors 4l and 42, respectively adapted to engage terminals '43 and 44.

Should the roll 11 suddenly speed up to drive the frequency changer 17 at an increased speed, an increased frequency will be applied to the secondary winding 18 of the electric differential to cause it to rotate in a counter-clockwise direction. Hence, discs 36 and 37 will bridge the terminals 38 and 39 to energize field-magnet winding 28 to rotate motor 26 in a counter-clockwise direction, thus operating, the rheostat arm 25 to decrease the field strength of the field-magnet winding 13.

At the same time, electromagnet coils 31 and 32 will be energized to restore arm 33 to its normal position to move the rheostat arm 25 a single step. If, however, the speed of the roll 11 has not yet been rectified, the electric differential will again operate in the same manner to move the rheostat arm another step. This operation will continue until the speed of the roll 11 has been mit the continuous rotation of the motor 26 and the associated rheostat arm 25.

This accelerating mechanism is diagrammatically illustrated in Fig. 1 as the arm 45 which projects between two sets of terminals 46 and 47. In the event that shaft 23 moves suddenly, arm 45 will close terminals 46, thereby energizing the coil of the electromagnetic switch 48 to open the circuit to the electromagnetic coils 31 and 32.

It will be understood that, should the speed of the roll 11 be suddenly decreased, applying a decreased frequency to the secondary winding 18 of the electric differential, it would operate the lever 33 to complete the circuit through terminals 43 and 44 to energize field-magnet winding 29, thus operating rheostat motor 26in a clockwise direction to increase the strength of the field winding 13 of the propelling motor. Likewise, if this change in speed should be sudden and large, the arm 45 would engage terminals 47 to de-energize the coil of electromagnetic switch 48, thereby rendering ineffective electromagnetic coils 31 and 32, as above described. The anti-hunting feature of this mechanism will be set forth in the detailed reference to Figs. 2 and 3, about to be made.

The actual construction of the corrective apparatus that is diagrammatically illustrated in Fig. 1 may be ascertained by reference to Figs. 2 and 3, wherein like parts are designated by like reference numerals. The frictional mounting of the lever 33 upon the shaft 23 is shown as accomplished by a coiled spring 49, which bears at one end against a collar 51, which is located beside the lever 33, and which bears, at its opposite end, against a nut 52 that is adapted to engage with the screw-threads 53 on the outer end of the shaft 23. It will be apparent that this nut may be adjusted to secure different degrees of tension upon the lever 33. A lock nut 54 is provided for holding the nut 52 in the adjusted position.

The accelerating and anti-hunting apparatus comprises a casing 55 having a hub 56, which screws upon the end of the screwthreaded portion 53 of the shaft 23. The casing has, on the rear face thereof, three collector rings 57, separated from the casing 55 by insulating material 58. The rings 57 are secured to the casing by any suitable means, such as the illustrated screws 59.- (Jo-operating with the collector rmgs 57 are appropriate ball-bearing mountings 64 and 65. Mounting 64 is located in the rear wall of the housing 55, while mounting 65 is carriedby a plate 66, which is secured at the front of the casing 55, as by means of the screws 67. Between the fly-wheel 63 and the mounting 64 is a spacing washer 68.

Alsomounted upon the shaft 62 is a block of insulating material. 69, to one side of which is secured the contact arm 45, diagrammatically shown in Fig. 1, and to the opposite side of which is secured a centering or holding arm 71. The arms and 71 are illustrated as secured to the block 69 by means of the screws 72, although it will be apparent that any other suitable connection thereto. may be made. Separating the block 69 from the fly-wheel 63 is a suitable washer 73.

Frictional engagement of the fly-wheel with the casing 55 is obtained by means of a spring 74, which bears against the block 69, and against which a washer 75 is held by means of a nut 76. The nut 76 is adapted to be adjusted upon the shaft 62 to thereby regulate the tension between the fly-wheel and the housing.

diagrammatically shown in Fig. 1, arm 45 normally extends between the two sets of contact members 46 and 47, respectively. As best shown in Figs. 3 and 4, these contact .members are mounted upon resilient arms 77, which are secured tobrackets 78 in any suitable manner. The arms 77 are spaced from each other and from the brackets by suitable insulating material, as indicated, for example, at "79. Thebrackets 78 are fastened to the rear wall of the casing 55 to permit the contacts to extend forwardly therefrom. Leads are taken from the contact members 46 and 47, through the resilient arms 77, to one set of the.screws 59, in any well-known manner, the two inner contact members 46 and 47 being connected to the middle screw 59, and each of the outside contact members 46 and 47 being respectively connected to the outer screws 59. The. circuit will then extend through collector rings 57 and brushes to bindingposts 60, whence the leads 81 and 82 will be taken to the proper points, in accordance with the circuits illustrated in Fig.1, to connect contact members 46 and 47 to the electromagnetic coils 31 and 32..

sition between contact The centering arm 71, which is located directly opposite the arm 45, is adapted to have secured, on opposite sides thereof, coil springs 83, which, in turn, are secured, at their free ends, to the adjusting screws 84, working in brackets 85-which are fastened to the rear wall of casing in a manner similar to that described for the brackets 78. The adjusting screws 84 have locking nuts 86 co-operating therewith for retaining the springs at the adjusted tension. It will be apparent that this tension may be so adjusted that the arm 45 will be maintained out of engagement with either of the arms 77 under; varying degrees of movement of the shaft 23.

The casing 55 is rendered dust-proof by placing a cap 87 on the face thereof and securing it to the casing by means of the screws 88.

It will be apparent, from the foregoing description, that the movements of the shaft 23, which are varied in accordance with changes in frequencies between the motor being controlled and the common frequency source, will be transmitted to the fly-wheel 63 which is in frictional engagement with the casing 55. However, if the shaft 23 is given a sudden and large turning movement in either direction, the inertia of the fly- -wheel 63 will prevent it from immediately acquiring the same rotational speed as shaft 23 and casing 55. Hence, the arm 45, which is. in frictional engagement with the flywheel 63, will close either the contact mem bers 46 or the members 47, depending upon the direction of rotation of the shaft This action will complete the circuit to the coil of switch 48, thus interrupting the circuit to. electromagnetic coils 31 and 32 at this point, thereby rendering the rheostat motor 26 free to move the rheostat arm 25 uninterruptedly to effect a quicker correction of thestrength of field-magnet winding 13 than would be accomplished by the normal step-by-step movement of said rheostat arm. j

It will likewise'be apparent that, as the shaft 23, carrying casing 55, continues to rotate, the fly-wheel 63 will soon acquire the same speed as the casing 55, with the result that arm 45 will again occupy a neutral pomembers 46 and 47, thereby disengaging the previously engaged sets of contact members. This action will occur just previous to the time when the controlled motor acquires abnormal-load conditions, but the momentum of the moving parts will be sufficient to carry the motor mto the normal-load condition without any overtravel, thereby avoiding hunting action by the motor or its regulator.

The return of the arm 45 to a neutral position is assisted by the action of springs 83. The strength of these springs may be so adjusted as to hold the arm 45 in the neutral position after the arm has been returned thereto, unless some condition arises whereby it may be desirable to complete the circuit through the opposite set of contact members to effect a prompt adj ustmcnt of the correction previously accomplished.

However, under normal conditions, when the arm 45 has operated and has been returned to a neutral position, the opposite set of contact members will not be closed by any acquired momentum of the fly-wheel 63. Hence, the frictional engagement of the fly-wheel with the casing 55 will be Sllfilcient to cause it to stop with the casing which, in turn, stops with the rotation of the shaft 28.

Modifications in the system and in. the arrangement and location of parts may be made within the spirit and scope of my invention, and such modifications are intended to be covered by the appended claims.

I claim as my invention 1. In a regulator system, the combination with a plurality of rotatable members, a plurality of dynamo-electric machines cooperating therewith, and a dynamo-electric machine common to all rotatable members, of means jointly controlled by said dynam0- electric machines for governing the speed of each rotatable member, and inertia-responsive means associated therewith for preventing hunting action of said machines.

v2. In a regulator system, the combination with a. plurality of rotatable members, a propelling motor for each of said rotatable members and means comprising a plurality of dynamo-electric machines cooperating therewith and means comprising a common dynamo-electric machine for controlling the propelling motors to operate the rotatable members at a constant-speed ratio, of inertia-responsive means for preventing overtravel of said machines.

3. In a speed-regulator system, the combination with a plurality of rolls, a propelling motor for each of said rolls, and an electric differential associated therewith, of means co-operating with said frequency changer comprising a contact-carrying device, a fly-wheel responsive to the movements of said frequency changer, and an arm frictionally carried by said fly-wheel and adapted to engage said contact device in a manner to regulate the operation of said motor.

4. In a regulator system, the combination with a plurality of dynamo-electric machines, and a constant-power machine, of a plurality of control means jointly governed by said machines, and inertia-responsive anti-hunting devices therefor.

5. In a speed-regulator 'system,-the combination with a plurality of rotatable members, a propelling motor for each of said members, a plurality of associated frequency changers, a frequency changer common to all of said rotatable members, and a motor-operated rheostat associated with each of said propelling motors and jointly controlled by the common frequency changer and the associated frequency changer, said rheostat normally having a step-bystep operation to govern the excitation of the associated propelling motor, of inertia-responsive means adapted to. render ineffective said step-by-step operation.

6. In a speed-regulator system, the combination with a plurality of rotatable members, a plurality of motors for rotating said members, and a frequency changer common to all rotatable members, of an electric differential associated with each rotatable member, means controlled by said electric differential for governing the speed of the propelling motor of the associated rotatable. member, and inertia-responsive means 00- operating therewith for preventing hunting action of said motors. f

7. In a speed-regulator system, the combination with a motor, a contact arm connected to the rotor of said motor and carrying contact members operated in accordance with the forward or the reverse movement of said rotor, a rheostat motor having differentially-related field-magnet windings respectively controlled by said contact members, and electromagnets connected in parallel-circuit relation to said field-magnet windings and adapted to return said contact arm to normal position, of means responsive to inertia action for rendering said electromagnets ineffective under predetermined conditions.

8. In a control system, the combination comprising a dynamo-electric machine adapted for forward and reverse operation, contact means controlled by said motor, electromagnets for returning the contactmeans to a neutral position a predetermined time after operation of the motor, and inertia-responsive means adapted to render said electromagnets inefi'iective under predetermined conditions.

9. In a control system, the combination with a control motor, of an auxiliary motor having diiferentially-related field-magnet windings energized in accordance with the operation of said control motor, electroresponsive means adapted to periodically de-energize said auxiliary motor, and inertia-responsive means operated by said control motor for rendering said electroresponsive means ineffective above a predetermined speed of said control motor.

10. In a regulator system, the combination with a plurality'of rotatable members and a propelling motor for each of said members, of means comprising a plurality of auxiliary members adapted to control the operation of said propelling motors to maintain a constant-speed ratio between said rtatable members, and an inertia-responsive anti-hunting device therefor.

11. In a speed-regulating system, the

combination with a plurality of rotatablemembers, means comprising a motor for propelling each of said members and dynamo-electric machlnesoperated in accord-- ance with the operation of said rotatable members, of meanscontrolled thereby comprising motor-operated rheostats adapted for normal step-by-step operation for varying the excitation of said motors to maintain a 'constantspeed ratio therebetween, and means for rendering ineffective said step-'by-ste'p operation,- including a fiywheel for preventing hunting action of said members.

'rheostat ineffective under 12. In a speed-regulating system, the combination with a rotatable member, a motor for propelling said member, and

-means' including a motor-operated rheostat for varying the excitation of said motor to maintain av substantially constant speed thereof, of regulating means for normally rotatablemembers, of mechanism for said control means comprising a contact device, a fly-wheel responsive to the movements of said control means, and an arm frictionally carried by said fly-wheel 'and adapted to engage said contact device.

14. In a regulator system, an electric differential and regulating means controlled in accordance with the operation ofsaid differential and including a fly-wheel adapted to accelerate the action of said regulating means under predetermined conditions.

'15. In a regulator system, an electric differential and regulating n'ieans controlled in accordance; with the operation of said differential and including a fly-wheel adapted to accelerate the action of said control means under predetermined conditions and to render said regulating means ineffective just prior to the obtaining of normal conditions.

16. In a regulator system, an electric differential and regulating means controlled in accordance with thcperation of said differential, including at casing connected to said differential, switch terminalscarried by said casing, a fly-wheel loosely mounted in said casing, a contact arm. engagedby said fly-wheel, said arm engaging different terminals under predetermined conditions,

and means for normally maintaining said contact arm out of engagement with said terminals. v

17. In regulator system, regulating means comprising a casing, switch terminals carried thereby, a fly-wheel loosely mounted therein, a contact arm frictionally engaged by said fly-wheel, said arm engaging different terminals under predetermined conditions, and means for normally maintaining said contact arm out of engagement with said terminals.

18. In a regulator, system, the combination with a plurality of rotatable members and a propelling motor for each of said members, of means for controlling said propelling motors to maintain a constantspeed ratio between said rotating members and-comprising a plurality of auxiliary members and an inertia-responsive device for accelerating the action of said means.

In testimony whereof, I have hereunto subscribed my name this 5th day of February, 1921.

STEPHEN STAEGE.

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