US1627832A - Speed regulation - Google Patents

Description

May 11o, 1927.

1,627,832 c. E. CARPENTER SPEED REGULATION Original Filed Aug. 24. 1921 2 Sheets-5h66?l l f) m lw J TQM J 24 @ma /1 TTOANEY May 1o, 1927. 1,627,332

C. E. CARPENTER SPEED REGULATION Original Filed Aug. 24. 1921 2 Sheets-Sheet 2 /fy Y I g #VWM f' A T TORNE Y length in its teuding'fbetween successive rolls,

toi-,the changes in slack in or sides oi the beltI occurring on a varia- Paitented May l0, 1927.

"UNITED As'rzvrleis i CHARLES E. CARPENTER, 0F NEW YORK, N. Y.

` eraan REGULATION.

' Application leil August 24, 1921, Serial No. 4.85128. Renewed January 7,

The general object of my present inven.- tion is'to provide improve'dmeans for malntaining predetermined relation between -the speeds of'rotation of two shafts.

My invention was prinarily devised, and is especially adapted forA use Vin controiling the speeds of a plurality of.A electric motors operated under the conditions existing-in the case of a paper making .'machine in which each of a plurality lof rolls over which the web ot paper stock passes is driven by Aan individual electric motor. In the operation of a paper making machine of this, type,

passage throuofh the machine as thestock is converted from pulp into finished paper. Furthermore, the degree of elongation or, in some cases, contraction in length of the web, occurring at different stagesA in the conversion of the pulp into finished paper varies with the conditions of operation. To avoid' stretching and rupturing on the one hand, or undue festooning on the otherhand, of the web portions exthe speeds of rotation of the different rolls must be very closely proportioned. lVith rolls of the same diameter drivenv by direct-ly con- A nected motors, the different motors must be operated at different speeds but the difference in speeds is small. Furthermore, there must be a capacity for making small variations in the relative roll speeds in response to changes in operating conditions.

' In utilizing the present invention to.con trol thel vspeeds Vof the different driving motors oi' a paper making machine of the type referred to above, or of any group of motors in which similar speed `relations arev desired, I provide each of the motors to be controlled 'with an automatic controller comprising a pair of pulleys and a coiinecting belt, and I drive one pulley at a speed which is the same as, or 'proportional to that of the motor, and drive the other pulley at the desired controlling cialtefwith the belt, mechanism responsive one or both turns tion in the Vrelative speeds ot' the two pulleys, to adjust the speed of the motor as required to restore the( desired speed relation. One pulley of each motor controlling mechanism maybe mounted directly on the ,shaft-of the controlled motor and the other individual synv pulley maybe driven by an the web ordinarily changes in speed, and assol tion;

peed

'to a synchronizing shaftcommon to all of.

the motors regulated. This synchronizing shaft may be" riven by one of the motors of the regulated group, or by an independent motor. The speed of" travel of each belt is thus a measure of the speed of the motor which it helps to control, and the relative speeds of the different motors may be varied by varying the relative belt speeds which can be accomplished in various ways.

My belt actuated control mechanism possesses the advantages of mechanical simplicity and reliability, andv insures a very sensitive and positive sp'eed control since a departure in motor speed vsufficient to effect a small portion of a revolution of one control pulley relative to the other will give a' substantial movement to the control'part or parts engaging the belt. Since the load transmitted by the control belt is small and practically constant, narrow smooth belts may ordinaril ube used withoutiincurring trouble from elt-slippage. Insome cases I may use sprocket chains or the like as the control belts and pulleys. in the formv of sprocket gears, thus eliminating all possi- .bility of slippage.

"The various features of `novelty which characterize my invention are pointed out should be had to the accompanying dravv-v be regulated as desired, vbut 5 ings and descriptive matter in which I have illustrated and described ments of my invention.

Of the drawings Fig. l is a diagrammaticvplan view of a group of motors having their speeds regulated in accordance with the present inven- I" ig. 2 is a diagram ,of the circuit connections which may be employed in connection with the apparatus shown in Fig. l; Fig. 3 is an elevation of a portion of the control mechanism employed in Fig. l;

Fig. 4'is an elevation taken at right angles to Fig. 3 with parts broken away and in section;

Figs. 5, y6 and 7 are diagrams illustrating preferred embodi- Leaassa angles to Fig. 8;

' ing an` -idler HA resting upon the lowerA Fig. 10 is a View illustrating a modica tion of the apparatus shown in Fig. 1; and

Fig. 11 is a diagrammatic representation.

of a modified form of control apparatus.

In the drawings, and referring first to the construction illustrated by Figs. 1 to 7 incl-usive, A, A', A2 and A3 represent motors, the power shafts A5 of which may be connected to the different rolls of a paper making machine, or to other devices which are to be driven in determined speed relations. To an extension A'3 of each of the motor shafts is coupled a shaft A7 carrying a cone pulley B. Y Associated with each pulley B isV an oppositely inclined cone pulley C, each pulley B and the' corresponding pulley C being coupled by a narrow belt D. As shown in Fig. 1 the different pulleys C are each driven through a corresponding pair of beveled fearsI C2 and E from a common synchronizing shaft E which is driven at the desired speed which ordinarily should be capaf ble of adjustment by any -suitable driving means. As shown the shaft E is provided with a driving pulley E2 through which the shaft E may be driven from a special motor or from an available line shaft or the like.

` The speed of each of the motors A, A', A2

and A2 isregulated by the corresponding belt D through mechanism comprising a frame F mounted on the motor bed plate A and adjustable along bed plate guides A11 in a direction parallel to the axes of the corresponding pulleys B and C. This adjustment is effected with the apparatus, shown by means of an adjustin screw F5 journalled in brackets A22 projecting from the bed plate A10 and provided with a hand wheel F6.

vThe screw passes through a threaded opening formed in a web portion F2 of the frame F. The frame F Lis formed with a guideway F for vertically movable cross heads G and GA. The cross head G carries a stud shaft G upon which is journalled aflanged'idler pulley H which rests upon the upper turn of the belt D, and the cross head GA carries a similar stud G support portion of the belt D. Associated with the idlers H and HA are electric contact devices I and IA, respectively, the relative movements of which, as the relative amounts of slack in the two turns of. the belt, vary,

directly or indirectly adjust the circuit con-- neetions of the controlled motor to thereby regulate its speed. As shown in Figs. 3 and 4, vthe Contact device I comprises a slotted arm having a spring contact finger and adjustably clamped by the nut G2 to the end of the stud .G for the idler H. The contact device IA is secured to the supporting stud shaft G for the idler HA and is provided with a plurality of Contact studs z' one or another of which is engaged by the contact finger I according to the distance between the axes of the idlers H and HA.

In the contemplated mode of operation of the apparatus shown in Figs. 1 to 7, the direction of the belt travel is that indicated by the arrows in Figs. 5, 6 and 7, and the normal conditions of each controlled belt D, when the proper speed relation between the corresponding pulleys B and C exist,wil1 be that illustrated in Fig. 6 in which there is about the same degree of dip or slack in each turn of the belt D. On a decrease in the speed`of the motor pulley B relative to the control pulley C, the upper turn of the belt tightens and the lower turn acquires more slack. The effect of this is to move thejidlers H and HA apart into the positions shown in Fig. 5, whereupon lthe contact devices I and IA will adjust the electrical connections for the motor to increase the speed of the latter and restore the condition illustrated in Fig. '6. IVhen, on the other hand, the pulley B is turning too rapidly relative to the control pulley C. more slack is given to the upper portion of the belt and the lower portion is tightened,

,and the idlers H and HA move toward one i another into the positions shown in Fig. 7 With a corresponding adjustment of the contacts I and IA and a resultant decrease in motor speed.

It will be understood, of course, that the contacts adjusted by the idlers H and HA may adjust motor circuits. or motor circuit controlling rela s in any of the various ways commonly emp oyed to adjust the speed of electric motors. In the arrangementshown diagrammatically by way of example in Fig. 2, the various motors A, A', A2 and A are direct current motors having their armatures connected by leads 3 and 4 `to supply conductors 1 and 2 connected'in turn to the brushes of the generator K. 'The latter has its field winding K energized by a separate exciter L which also supplies current for energizing the field windings A15 of the motors A, A', A2 and A. The exciter L is shunt wound and regulating rheostats R' and R2 are placed in the field circuits of the generator K and exciter L respectively.

The field circuit for each of the motors A, A', A2 and A3 includes in series lwith the tield winding A15 a hand operated rheostat R, the contact finger I, and more or less of a resistance r which is connected at intervals to the contact studs z' of the controller conllo tact member IA, so that when the idlers II"` 5 proach one another. It will be unde ance -r is cut into circuit, the motor field current is correspondingly reduced, and the motor speeded up, an opposite eect being produced when the idlers H and HA' apof course that in practicethe various' rheoiA statsR, lt. and R areO adjusted to suplly approximately the pro r amount of ve tric energy to each of t e motors A, A', A

l0 and A, to enable the latter to carry its load at the proper speed, and the automatic control mechanism are then called uponto effect only vthe slight variations in motor field strength required to maintain the exact speed relation desired between each motor and its control piulley C. When the speed of the paper ma ing machine as'a Whole is to be varied, as it may be by adjustment of the rheostat R', the speed of rotation of the 2 shaft E is correspondingly varied. When it 25 sponding belt D axially is desired to vary the relative speed of any of the controlled motors, and the others, this is effected by rotating the threaded shaft F! of the said one motor to shift the correof .the cone pulleys C and B in one direction or the other.

In Fig. 11 I have illustratedby way of example an arran ement in which the motor speed is'regulate, not by a step by step 3 variation of the resistance in the field wind- *3 run ing current, but by alternately cutting into fand out of the motor field ance of such magnitude that when included in the field circuit the motor will tend to at a speed above that desired, and when Lout, outof the field circuit the motor will tend to yrun at a speed below that desired. The controlled motor As shown in Fig. 1l has its armature connected between supply -conductors 10 and 11, and has its lield winding A16 connected inshunt to the armature in a circuit including a hand operated rheo- `stat Rs and an automatic controller resistance T5. One terminal of the last mentioned resistance is connected to a contact 11 carried by the controller idler pulley H, and the controller idler pulley HA carries a cooperating contact I11 connected to the opposlte terminal resistance 1'5 or to an, intermediate portion of the latter. Advantageously the connectionbetween t e contact I11 and the resistance r is made through a connector R1 which can be manually adjusted along the resistance r to obtain theodesired sensitiveness of regulation.

With the arrangement shown in Fig. 11 when the motor Ag runs above speed the con- 'tacts I10 and I11 are moved together by the resultant changes in belt slack and the correspondin portion of the resistance fr isshort circuited to thereby increase the field strength and decrease the motor speed. When the motor slows down the contacts 11 and Il1 are separated and the motor field is correspondingly weakened thus reducing rstood,/

circuit a resist-` the motor speed. -In the practical operation of y/this sort of control apparatus, the contacts It", and I1u engage one another and lseparate at fre uent intervals and the belt /actuated contro ing mechanism thus holds the motor speed at the desired mean between its maximum and minimum speeds.

A special advantage of my improved control mechanism arises from the fact that the control belts D have practically no load to transmit and hence the belts may be light in weight and narrow andwithout danger of belt slippage prejudicially affecting the desired speed control. The two idlers, H and HA balance one another so to speak,-and thus maintain ractically uniform tension on both turns ci) the belt under the normal condition-of operation. It will be obvious, of course, that the greater the total amount of slack in the belt, the greater the ran e of relative movement of the idlers 'H and A, and the smaller the changes in 'belt tensionproduced by a given relative movement of approach or separation of t1r idlers.

In the modification illustrated in F and 9, the idlers H and HA carry adjustable spring contact fingers IB andV IC, respectlvely, each of which cooperates with a corresponding set of resistance studs a carried by a rheostat element ID rigidly secured to the controller frame F. With the modification shown in Figs. 8 and 9 the idlers H and HA with their supporting parts and contacts may be counterparts so that each idler and the parts connected to it exactly balances the other. v

While I prefer, in order to increase the range of movement of the control parts and toincrease the number of steps by which the -control resistance may be. varied, to utilize the changes in slack in both'partsof the belt, it is obvious, of course, that whercconditions make this desirable, the slack'variations in one part only of the belt may be utilized to control the motor speed. For example, with the apparatus shown in Figs. 8 and 9, the contact IG and cooperating studs ia may be omitted without any change -in'operation other than a decrease in the number of steps by which the controller rcsistance may be automatically adjusted.

In the modification shown in Figs. 8 and 9, the relative speed of the cone pulleys may be varied, as in the apparatus shown in Figs. 3 and 4, by the simple adjustment axially ofv the pulleys Baand C of the frame F in which the idlers H and HA are ',mounted. This mode of Avarying the speed relation maintained between the synchronizing shaft E-and the motor driven shaft A7 over which the control belt of each controller runs is a very good one from a practical standpoint because of the ease and reliability'of opera tion, and the relative simplicity of the mechllo anism required, but this variation 'in relative speed can obviously be obtained in other ways as shown for example in Fig. 10.

from the synchronizing shaft- E by a variable speed gear which as shown comprises an element C" splined on the shaft C and provided with a conical surface C12 engaged by a friction driving wheel Em splined on the shaft E. The member Cf can be axially adjusted along the shaft C asby means of a lever CF and a screw C14 threaded through the stationary abutment A30. The friction driving wheel E is held against the conical surface C12 in the different axialadjustments of the latter, by means of a spring E@ acting between the wheel E10 and a collar E12 secured to the shaft E. The idler actuated control mechanism responsive to changes in slack in the beltDA may be exactly like that shown in Figs. 3v and 4 except that in this case the frame FA in which the belt engaging idlers are mounted may be stationary.

lVhere the adjustment in relative speed of the motor driven pulley over which theA control belt runs and the synchronizing shaft is not obtained by an adjustment of the belt l i' axially of the pulley as in Figs. 3 and 4, the

control belt may bea `sprocket chain, and the pulleys over which it runs may be sprocket wheels as shown in Fig. 10 fthus eliminating all possibility of belt slippage. In' general, however, since the control belts transmit no appreciable load, belt slippage Will give no trouble when smooth belts are used, and in A practice I would ordinarily prefer to use asmooth belt and simple flanged pulleys in lieu of the chain DA and wheels B10 and C10 in apparatus in which the adjustment in relative speed is effected as in Fig. 10.

While in accordance with the provisions of the. statutes I have illustrated and. de-

scribed the best form of my present invention now known to me, it will be apparent to those skilledin the art that changes mayQbe made in the form of my invention withoutr departing from the spirit of'my invention as set forth in the appended claims, and that certain features of my invention may somet times be used to advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire'to secure by Letters Patent, is:

1. 'In a system comprising a motor, a synchronizing shaft, a pulleydrivenby the motor, a vpulley driven by the shaft, a belt.`

looped about the pulleys, the -improved means for maintaining a definite speed rela'- tion between the motor and shaft consisting of a motor speed regulator, and means controlled by'variations in the length of said belt between given points, resulting from variations in the relative speeds of said pulleys, for adjusting said regulatorias required.

2. Ina system comprising a motor, a synchronizing shaft, a pulley driven by the motor, a pulley driven by the shaft, a belt looped about the pulleys, and a motor speed regulator, the improvement which consists in means actuated by variations in the relative pulls of the pulleys on the two sides of Ithe belt loop for adjusting said regulator as required ito maintain a definite speed regulation between the motor and shaft.

3. In a system comprising a motor, a synchronizing shaft, a pulley driven by the motor, a pulley driven by the shaft, and a belt looped about said pulleys, the improved means for maintaining a definite speed relation between the motor and shaft, consisting of a speed regulator for said motor comprising a series of contact studs and a cooperating switch member, and idlers bearing' on the two sides of the belt and effecting movements of the switch member over the contacts as the idlers assume different positions in response to changes in the relative lengths of the two sides of. the belt loop as required to maintain a definite speed'relation between the motor and shaft.

4. In a system comprising a motor, a synchronizing shaft, a pair of cone pulleys driven one by the motor and the other by the 10 shaft, a belt looped about the pulleys, and a motor speed regulator, the improvement which'consists in means actuated by variations in the relative lengths of the two sides of the belt loop for adjustin said regulatoi'1 10i as required to maintain a de nite lspeed relation between the motor and shaft.

5. In a system comprising a motor, a synchronizing shaft, a pair of cone pulleys driven one by the motor and the other by 11( the shaft, and a belt connecting said pulleys, the improved means for maintaining different definite speed relations between the motor and shaft, comprising an idler pulley engaging the belt, a support on which said 1li idler pulley is mounted with freedom to move as required to maintain engagement vwith the belt as the lengthof said belt between given points varies, means for adjusting said support to adjust the belt axially 1'3 quired to maintain a definite speed relation between the-motor and shaft.

6. In a system comprising a motor, asynchronizing shaft, a pair of cone pulleys driven one by the motor and the other by the shaft, and a belt looped about the pulleys, the limprovement which consists in a 13 support, a

belt axia ly of the pulleys, and motor speed f regulating provisions including an electrical said idlers.

switch mechanism mounted on said support and actuated bythe movements of certain of 7 In a system comprising a plurality o f motors and La synchronizing. shaft, the improved means or maintaining denite speed relations between the different motors Vand pair of idler pulleys engaging the said shaft consisting of an individual control device for each motor, which comprises a pulley driven by the motor, a pulley driven by the shaft, a belt connecting the pulleys, and means responsive to the variation in the relative lengths of the two sides -of the belt loop for a justing the speed ofthe corresponding motor as required to maintain definite speedrelation between the motor and `shaft Signed at New York in the county of New York and State of New York this 23rd day of August, A.A D. 1921.

CrnaiRLE's E. CARPENTER.

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