US2219857A - Paper machine drive - Google Patents

Description

Oct. 29, 1940- M. T. WESTON PAPER MACHINE DRIVE 6 Sheets-Sheet 1 Filed Jan. 7, 1938 O 29, 0- M. T. WESTON 2,219,857

PAPER MACHINE DRIVE Filed Jan. 7, 1938 6 Sheets-Sheet 2 INVENTOR Oct. 29, 1940. WESTON 2,219,857

PAPER MACHINE DRIVE Filed Jan 7, 1958 s Sheets-Sheet s [NVEN OR Oct 4 M T. WESTON 2219 85? PAPER MACHINE DRIVE Filed Jan. 7, 1958 6 Sheets-Sheet 4 IN VNTOR ()(til.; 29, 1940. M. WESTON 2,219,857

PAPER MACHINE DRIVE Filed Jan. '7, 1938 6 Sheets-Sheet 5 m r\ i Z g w h, 1

v x \o n fi I 1 I w v a w '\I N N Q- a r "0 G o 7 N V '0 o H) V INVENTOR 2/ m m Och 1940- M. T. WESTON PAPER MACHINE DRIVE 6 Sheets-Sheet 6 Filed Jan. 7, I938 INVENTOR I Patented Oct. 29, 1940 'IUNITED STATES PATENT OFFICE Milton T. Weston, Red Bank, N. J., assignor to West Virginia Pulp & Paper Company, New York, N. Y., a corporation of Delaware Application January 7, 1938, Serial No. 183,745

8 Claims.

Mypresent invention relates to improvements in drives for papermaking machines, and more particularly for the individual cylinders of the drier section. The present practice is to positively gear all of the drier cylinders in the section together so that the peripheries of all of the cylinders have exactlythe same velocity. On account of the snubbing action of so many cylinders, and further because the tension in the felts holds the paper web firmly against the surfaces of the drier cylinders, there can be no slipping of the paper web to allow for the normal shrinkage which, in a modern machine, is very considerable-probably as much as ten to twenty feet between the first and last drier cylinder. The efiect is, in reality, the stretching of the paper web to this extent in the machine direction, causing an abnormal shrinkage in the cross direction. This stretching of the paper results in a pronounced orientation of the fibers in the machine direction at the expense of the cross direction, making the paper much stronger in the one direction than in the other. Repeated tests have shown that the prevention of the normal shrinkage of the paper web produces a sheet 2 times stronger in the machine direction than in the cross directiona very undesirable result. Other tests have proven that most of the fiber orientation in the present system occurs at the drier section. If this orientation of the fibers in the machine direction can be prevented by allowing the paper web to shrink normally, a condition will result wherein the paper web will be more nearly equal in strength in both directions-a most desirable result.

The principal object of my invention is to provide a drive mechanism for the drier unit in which the individual cylinders of the unit may be driven at speeds which diifer by extremely slight increments from one another, thereby making it possible to obtain the required fineness of adjustment necessary for a progressive difference' in peripheral speeds of the several drier cylinders from the first to the last to allow for the proper shrinkage of the paper web and thus prevent orientation of the fibers in the machine direction.

A further object is to provide an improved drive arrangement for the drier units in which'my improved micro variable drive is applied to a selected group of cylinders.

A further object is-'to provide an improved mechanism employing a planetary gear train and means for driving same in which variation in drive of the unit as a whole will not aifect the (Cl. 3H8) relative speeds of the individual cylinders one to another.

A further object is to provide an improved means of disposition of the planetary gear motors.

Further objects of the invention and advantages will be apparent from the following detailed description taken with the accompanying drawings in which Fig. 1 is a side elevation of anillustrative embodiment, a part being shown in cross section taken on line Il of Fig. 3.

Fig. 2 is a cross sectional view taken on a line 22 of Figs. 3 and 4 showing the supports for the control motors.

Fig. 3 is a cross sectional view of a unit of my invention on a line 3-3 of Fig. 1.

Fig. 4 is a cross sectional view similar to Fig. 3 showing a difierent form of the same mechanism.

Fig. 5 is a side elevation showing several units of my invention in operative relation to each other and reveals the means for supporting all of the control motors independent of the paper machine.

Fig. 6 is a diagrammatic view illustrating the use of a so called silent driving chain instead of the train of meshing gears.

Fig.- 7 shows a circuit which may be employed for connecting up the auxiliary motors.

Fig.'8 is a diagrammatic view of the drier cylinders in which my improved micro variable drive is applied to a selected group of cylinders; and

Fig. 9 represents a curve indicating a shrinkage of the paper as it passes through the rolls, and isso related to Fig. 8 that a vertical line drawn upwardly from any cylinder of Fig. 8 in tersects the curve at the point indicating approximately the amount of shrinkage of the paper at that particular cylinder.-

In the drawings, l is the trunnion on which a drier cylinder 2 is revolvably mounted. A spider 3 is keyed on the end of the trunnion I and is provided at its periphery with an integral radial flange 4 and a preferably removable radial flange 5. A gear ring 6 is revolvably mounted on the peripheriesof radial flanges 4 and 5 as clearly shown in Figs. I and 3. The outer periphery of the gear ring 6 is provided with sp'ur teeth to mesh with similar teeth on gear rings 6 carried by adjacent units as shown in Fig. 5. The inner periphery of the gear ring 6 has internal spur teeth I which are disposed in the annular space 8 between the'flanges 4 and 5 as shown at the bottom of Fig. 3 and in the broken section in Fig. 1.

The rim of the spider 3 has a plurality of transverse pockets or recesses 9 in which are located spur pinions H) with integral shafts revolvably mounted in flanges 4 and 5 in proper relation to mesh with the internal teeth I on the gear ring 6. Obviously, turning the pinions l about their axes will cause a rotational movement of the gear ring 6 with respect to the flanges 4 and and consequently with respect to the spider 3.

On the outer ends of the pinion shafts H are mounted worm wheels l2 meshing with worms 3 operably mounted on shafts H which extend somewhat radially toward the axial center of the unit. The inner. ends of these shafts l4 are supported in a casing l5 attached to the hub of the spider '3. Bevel pinions 6 are mounted on the inner ends of shafts l4 within the casing i5 and mesh with a bevel gear I! mounted on a sleeve l8 revolvable on the steam inlet pipe l9 secured to and revolving with the trunnion I. A wormwheel 20 is mounted on the outer end of the sleeve I8 and is driven by a worm 2| mounted in operable position in the casing 22 which preferably is suspended from the sleeve H! by its own bearings 23 on either side of the worm wheel 20.

A fin 24 projects downwardly from the casing 22 and supports the angles 25, which are securely attached to it in a horizontal position, and which support the control motors 26 in axial alignment with the worm 2| in casing 22. By reference to Fig. 5 it will be seen that these angles 25 extend continuously past all of the units of the drier section of a paper machine and support all of thecontrol motors 26. This construction entirely avoids any attachment to the paper machine for supporting the control motors and also makes cumbersome and obstructing supports on the floor unnecessary.

The customary arrangement for admitting steam to a drier cylinder and removing condensate therefrom is illustrated by the parts A and B, respectively, in Figs. 3 and 4.

Fig. 4 shows the embodiment of my invention in a more compact form. Instead of the gear ring 6 I use a complete gear 21 having a hub 28 which is somewhat larger in diameter than usual in order to accommodate-the internal teeth 29 and permit the mounting of the pinions III in proper positions to mesh with the internal teeth. This also brings the worm wheels I2 and worms l3 toward the axial center as far as structurally possible. The hub 28 is revolvably mounted on flange 30 keyed on trunnion and on the removable flange 3| and the pinio n shafts II are also revolvably mounted in these flanges.

In this same figure I show another modification in constructionwherein I provide a sleeve 32 integral with or attached too the removable flange 3| and concentric with the steam inlet pipe |9 but not in contact with it. This permits the ready removal of the steam inlet pipe i9 without disturbing the unit. The worm wheel 33 is revolvable on the sleeve 32 and has its hub extended to receive the bevel gear 34 secured thereon. The control motor mounting is the same as described for Fig. 3.

For an understanding of the operation of the device of Figs. 1-3, assume that it is desired to drive the cylinder 2 at the same speed (R. P. M.) as the gear 6. To accomplish this it is'evident that the spur pinions (planets) It should remain fixed upon their axes. For this condition to occur the bevel gear must remain fixed in relation to the spur gears I6 and hence gear I! must be driven at the same speed (R. P. M.) as gear 6. If, however, the auxiliary motor is driven at a somewhat faster speed the arrangement is such that the pinions II will be rotated slightly in the same direction as the inner gear! and hence will cause a corresponding diminution of speed of the flange 5, spider 3 and cylinder 2. The operation of Fig. 4 is precisely similar.

Fig. 6 shows the use of the silent type of sprocket chain 35 in which alternate links are reversed in order to operate on sprocket wheels 36 which are alternately presented on both sides of the chain 35 as illustrated in this figure. It will be understood that sprocket teeth are provided in place of the meshing gear teeth previously described.

In the operation of my invention all or a portion of the drier cylinders are progressively slowed down as the paper web advances. The reduction in the peripheral speed of the successive cylinders represents the exact amount of shrinkage in thev paper web, so that shrinkage will take place substantially equally in both directions resulting in the paper having approximately equal strength in the machine and cross directions. The adjustment and regulation of the speeds of the several cylinders in my invention is accomplished by varying the speeds of the several control or auxiliary motors 26--one motor being provided for each drier unit as shown in Fig. 5. The control motor 26, operating through the gearing as described, slows down its corresponding drier cylinder in proportion to its speed. That is, the faster the motor speed the slower the speed of the corresponding drier cylinder. Each successive control motor will therefore run slightly faster than the preceding one and these speeds are determined and regulated to slow down the drier cylinders progressively to allow for the normal shrinkage of the paper web.

In Fig. 7 I have shown a circuit which may be employed for connecting up the auinllary motors 26 by means of which the speed of the drier unit may be varied as a whole without altering the relative speed of the individual cylinders. As shown, a source of D. C. power 50 is employed of constant electromotive force (E. M. F.) Source 50 is connected to a motor 5| driving a D. C. generator 52, means being provided'for varying the speed of motor ill in the form of rheostat 53. The circuit 54, energized by generator 52, is now employed for driving the main motor 54a for the drier unit, the same driving the gear train comprised of the intermeshing annular gears 6 by a pinion 541) through the branch circuit 55, while branch circuit 56 is employed to drive the armatures 51 of motors 26. The fields for the motors 26 are indicated at 59. It will be apparent thus far that the flux afiorded by fields 59 remaining constant, the speed of motors 26 will vary automatically with that of the main motor 54a connected with branch circuit 55. It is desirable, however, to vary the speed of the motors 26 by slight increments with respect to one another, and for this purpose circuit 66 is provided, also energized by generator 50 and therefore having a constant E. M. F., such circuit feeding the fleld circuits 6| as shown. It is now merely necessary in such circuits 6| to provide rheostats 62 by means of which to alter the flux of the flelds 59, and hence provide means for varying the speed of the motors 26 with respect to one another. It will therefore. be seen that by'adjusting the rheostat 53, the speed of the main motor 54a and of the auxiliary motors will be varied as a unit, whereas adjustment of the individual rheostat 62 will vary the speed of the individual cylinders with-respect to one another.

I have also discovered that the shrinkage of the paper is not uniform as the paper passes from drying cylinder to drying cylinder, but instead, is represented by a curve having a form as shown by Fig. 9. Reference to this curve will bring out the fact that as the web comes from the presses containing, say, about 66% moisture, it does not undergo any appreciable shrinkage for perhaps one-third of the entire drier section represented by A, Fig. 8, the heat of the cylinders going to heat up the relatively cold, wet paper. However, beginning at period 3 the continued gradual heating of the web results in evaporation of the moisture, at which time shrinkage takes place. The rate of shrinkage at this point is substantially uniform until approximately another third of the drier units have been traversed. Beginning at section C, however, the shrinkage again falls off because of the lowered rate of evaporation, and the curve becomes substantially flat, as indicated in Fig. 9.

In my present invention I take advantage of this difference in the rate of shrinkage by driving the cylinders of section A together at a uniform rate one with respect to the other. However, in section B wherein the greater shrinkage takes place, I provide for individual cylinders having a differential drive with respect one to the other, employing the means for this previously de scribed. After section B is traversed the cylinders comprising group C are driven again at uniform rate relative one to another, except, however, the unit as a whole is driven at a speed which is proportionatelyslower than the speed of the A units. This result may be brought about by increasing the size of the gears in group C, thus causing the cylinders driven thereby to run proportionately slower and at exactly the same speed as that of the last cylinder in group B and preventing any strain in the paper as it passes from group B to group C. In Fig. 9, 65 represents the slight amount of. shrinkage the paper has undergone at the start of the group B, while 61 indicates the amount of shrinkage occurring in group C, the bulk of the shrinkage occurring in group B being represented by 66. While the amount of shrinkage represented by 61 is slightly greater than that represented by 65, this does not injure the paper, since the web is substantially formed by the time it reaches group C and will have sumcient elasticity and slip to take care of this remaining shrinkage without injury.

The arrangement just described effects a substantial economy of installation and in most cases sacrifices no substantial benefit of the invention. However, in special cases, especially where the shrinkage characteristics of the paper differ from the normal, for the best results group C driers may be eliminated and group B made large enough to complete the drying. In such a case the saving in installation will berepresented by that of group A.

I wish it understood that various changes will occur to those skilled in the art from the specific embodiments shown, which are illustrative only,'

without departing from the spirit of my inven-'.; This tion or the scope of the appended claims. application is a continuation in part of my application Serial No. 96,805 filed August 13, 1936.

I claim:

1. In a paper making machine, a group of drier cylinders, supporting shafts or trunnions for said cy inders, means for driving said cylinders including drive receiving members respectively associated with said cylinders and operatively connected thereto, driving gears concentric with respective of said drivereceiving members, said driving gears meshing with one another to constitute a gear train in which each driving gear has approximately the same speed of rotation, differential gear connections between corresponding of said driving gears and said drive receiving members, and means for actuating said connections to vary the speed of the individual drier cylinders of the group in an amount to compensate for the shrinkage of paper from one drier cylinder to another.

2. In a paper making machine, a group of drier cylinders, supporting shafts or trunnions for said cylinders, means for driving said cylinders including drive receiving members respectively associatedwith said cylindersand operatively connected thereto, driving gears concentric with respective of said drive receiving members, said driving gears meshing with one another to constitute a gear train in which each driving gear has approximately the same speed of rotation, differential gear connections between corresponding of said driving gears and said drive receiving members, and means for actuating said connections to vary the speed of the individual drier cylinders of the group in an amount to compensate for the shrinkage of paper from one drier cylinder to another, said actuating means comprising an electric motor individual to each of said difierentially driven cylinders. and supporting means for each of said motors suspended from a plurality of said shafts or trunnions.

3. In a paper making machine, a group of drier cylinders, supporting shafts or trunnions for said cylinders, means for driving said cylinders including drive receiving members respectively associated with said cylinders and operatively connected thereto, driving gears concentric with respective of said drive receiving members, said driving gears meshing with one another to constitute a gear train in which each driving gear has approximately the same speed of rotation, differential gear connections between corresponding of said driving gears and said drive receiving members, and means for actuating said connections to vary the speed of the individual drier cylinders of the group in an amount to compensate for the shrinkage of paper from one drier cylinder to another, said actuating means comprising an electric motor individual to each of said difierentially driven cylinders and supporting means for said motors comprising a bar upon which said motors are attached, and sleeves on a plurality of said shafts or trunnions and supporting said bar.

4. In a paper making machine, a group of drier cylinders, supporting shafts or trunnions for said cylinders, means for driving said cylinders including drive receiving members respec tively associated with said cylinders and operatively connected thereto, driving gears associated with respective of said drive receiving members, said driving gears meshing with one another to constitute a gear .train in which each driving receiving members, a main electric motor for driving said drier cylinders through said gear train, means for actuating said connections to vary the speed of the individual drier cylinders of the group comprising auxiliary electric motors, one for each connection, electric connections between said main motor and said auxiliary motors including means for varying the speed of said auxiliary motors in accordance with said main motor, and means for changing the speed of said auxiliary motors independently of said main motor.

5. In a paper making machine, a group oi drier cylinders, supporting shafts 'or trunnions for said cylinders, means for driving said cylinders including drive receiving members respec tively associated with said cylinders and operatively connected thereto, annular driving gears having gear teeth on both their inner and outer surfaces and being concentric with respective of said drive receiving members, said driving gears meshing with one another to constitute a gear train in which each driving gear has substantially the same speed of rotation, planetary gears between corresponding of said driving gears and said drive receiving members, means for driving -tiveiy connected thereto, annular driving gears having gear teeth on both their inner and outer surfaces and being concentric with respective of said drive receiving members, said driving gears meshing with one another to constitute a gear train in which each driving gear has substantially the same speed of rotation, planetary gears between corresponding of said driving gears and said drive receiving members, means for driving said planetary gears to vary the speed of the individual drier cylinders of the group in an amount to compensate for the shrinkage of paper from one drier cylinder to another, said means last mentioned comprising a rotatable sleeve concentric with each supporting shaft or trunnion, said sleeves accommodating steam inlet pipes for heating said cylinders.

7. In a paper making machine, a group of drier cylinders, supporting shafts or trunnions for said cylinders, means for driving said cylinders including drive receiving members respectively associated with said cylinders and operatively connected thereto, driving gears concentric with respective of said drive receiving members, said driving gears meshing with one another to constitute a gear train in which each driving gear has approximately the same speed of rotation, a main electric motor for driving said cylinder through said gear train, differential gear connections between corresponding of said driving gears and said drive receiving members, and means for actuating said connections to vary the speed of the individual drier cylinders of the group in an amount to compensate for the shrinka e of paper from one drier cylinder to another, said actuating means including an auxiliary electric motor in circuit with said main motor whereby said auxiliary motor keeps pace with said main motor, and a speed adjusting device associated with said auxiliary motorto vary the speed of same independently of said main motor.

8. In a paper making machine, a micro drive for individual cylinders of the drier section, comprising a driving member in the form of an annular gear having gear teeth'both on its inner and outer surfaces, the outer teeth of said gear adapted to mesh with the outer teeth of like gears in a nest of driers, and to be driven at a relatively constant peripheral speed, driving means for same, a drive receiving member connected to a drier cylinder and co-axial therewith, planetary gears adapted to mesh with said teeth on the inner surface of said annular gear and with teeth on said drive receiving members and means for driving said planetary gears at a variable speed to vary the speed of said drier cylinder.

MILTON T. WESTON.

Images