US3178744A - Internally driven scratch brush - Google Patents

Description

R. F. CHRISTIAN INTERNALLY DRIVEN SCRATCH BRUSH A riLZOQ 1965 Filed July 15, 1963 6 Sheets-Sheet 1 FIG 4A 1 9 r if,

v INVENTOR. m

ROBERT F. CHR is-riAN ATTOR IVE) April 20, 1965 R. F. CHRISTIAN INTERNALLY DRIVEN SCRATCH BRUSH 6 Sheets-Sheet 2 Filed July 15. 1963 /7////// r/////////4 ////////w///W///////- I INVENTOR ROBERT F. CHRis-riAN A'I'ToRN EV April 20, 1965 Filed July 15, 1963 R. F. CHRISTIAN INTERNALLY DRIVEN SCRATCH BRUSH 6 Sheets-Sheet 3 Iwvawron Roam-r F. CHR isTiA ATTORNEY April 20, 1965 R. F. CHRISTIAN INTERNALLY DRIVEN SCRATCH BRUSH 6 Sheets-Sheet 6 Filed July 15, 1963 FIG. 6.

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N r M M K T my J TM R E wi United States Patent 3,173,744 INTERNALLY DRIVEN SCRATCH BRUSH Robert F. Christian, World Trade Center, San Francisco 11, Calif. Filed July 15, 1963, Ser. No. 295,652 8 Claims. (Cl. --21) The present invention relates to scratch brushes.

Scratch brushes may be used for various purposes and a particular use is to remove scale particles which adhere to work rolls of rolling mills when aluminum plate is being rolled between them.

When an aluminum strip passes between work rolls scale particles adhere to the work rolls, and are removed by brushes and pressure jets so that work rolls continuously present clean work faces to the strip. This strip passes through a number of such roll pairs and is progressively reduced in thickness and is increased in width. This strip comes out of a furnace at a temperature exceeding 700 F. As it contacts the work rolls, it reduces in temperature and transfers much of its heat to the work rolls. It follows that the work rolls operate at various temperatures varying from as high as 600 F. at the first stand, to as low as 200 F. to 300 F. at the last roll pair.

As the work rolls contact the sheet, large quantities of scale adhere to the faces of these work rolls, which scale must be continuously removed to prevent imbedding into or scarring of the aluminum strip. This is accomplished by scratch brushes and jet streams of soluble oil and water. The solution is mostly caught up in gutter and what falls on the strip is blown oil? by compressed air, and the solution from the lower brush is caught in a lower gutter not shown.

Rotary cylindrical scratch brushes relatively smaller in diameter to the work rolls, usually rotate at a pcripheral speed of 4,000 f.p.m. (feet per minute) counter directionally and many times faster in surface speed than the surface speed of the work rolls. This brush action generates high temperature in the bristles which is partially absorbed by the solution, but solution temperature is of the order of 140 F. These brushes are also at times arranged to axially reciprocate with a stroke action up to 1" while rotating. Heretofore, it has been customary to drive these brushes from a prime mover (of the order of to H.P.), through a speed reducer and chain drive to an extended shaft on the brush cylinder adapted to be driven. Other drive arrangements have been used, such as bevel gearing.

Depending on operating conditions, it is sometimes important to maintain uniform brush pressure and accurate alignment of the brush to the work roll. At other times it is desirable to vary the axial alignment of the brush and the work roll, and have variable brush pressures across the face of the work roll. The life of the brush and the quality of aluminum strip, are dependent upon these features. It is obvious that these requirements, together with very limited available space, impose severe handicaps on the drives presently being used.

It has been found that the kind of drive arrangement, presently being used, involved as it is with the varying requirements of alignment and brush pressure, has been expensive, of great bulk, complicated in design, and resultant in shortened brush life, increased maintenance, and has a direct bearing on the quality of the strip. Vibrations and certain unbalances associated with this drive are suspected of causing somewhat mysterious ghost" patterns in the strip.

It should be mentioned that these brushes operate flooded with jets of Water soluble oil, at a rate of about 500 gallons per minute to facilitate removal of the scale particles from the bristles. Thus the all-exposed parts of the drive mechanism and the associated adjustment mechanism are subject to flooded operating condition that is most undesirable, and results in high cost of maintenance. Furthermore, the periodic adjustment of the brush to the roll requires constant and careful realignment of the separate entities of the drive mechanism.

Furthermore, from such drives there is a considerable loss of power in transmission from the motor to the brush contactsas much as 40% An object of the present invention is to provide a scratch brush assembly of compact design thus eliminating the chain drive or bevel gearing drive and minimising the vibrations, unbalances and power losses of such drives.

A further object of the invention is to provide a scratch brush assembly wherein the prime mover is not exposed to the jet streams from the pressure jets.

Another object is to provide a scratch brush assembly wherein the brush may easily be adjusted.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawing, wherein,

FiGURES 1A, 1B, 1C, together form a sectional elevation of a scratch brush assembly made in accordance with the invention,

FIGURE 2 is a sectional elevation taken on line AA of FIGURE 1, and

FIGURES 3 and 4 show a method of mounting the brush assembly at the ends thereof;

FZGURE 5 shows an alternative method of mounting the brush assembly; and

FTGURE 6 is an enlarged sectional elevation of part of the scratch brush assembly.

A specially constructed wire bristle assembly 2 comprising a channel section formed to crimp the bristles U shape, is spirally wound about a tubular mandel 1.

At the starting end 3 the winding is attached to a flange 4 which comprises an extended portion of the bearing cage 1%. As shown in FIGURE 6, the flange 4 is grooved and the channel section or horseshoe shaped metal base Ztll extends into the groove and is held therein by a set screw 203. Preferably three set screws 203 are used to pinch the end of the channel section 201. The flange 4 is secured to the body of the mandrel by set screws 202 that are also in the spiral groove. Four set screws 202 are preferably used. The bristles are trimmed oif as at 204 to permit a balancing collar to be slipped over the flange and this balancing collar is prevented from slipping off by set screws 265 that enter into the spiral groove of the flange. The winding terminates at 5 where it may be attached to a sliding ring 6 by means similar to those shown in FIGURE 6. Another ring 7 is attached to the end cage 11 in a manner that permits it be screwed on to ring 6 so that the latter compresses the bristle assembly 2. The ring 7 is threaded opposite hand to the hand of the spiral bristle assembly. Sliding ring 6 has serrations (not shown) that engage the bristles of the assembly just above the channel section in such a manner as to hold the end of the bristle winding from escapement. Ring 7 has a plurality of drilled holes which can be used in conjunction with a spanner wrench to tighten this ring in the threads, and these holes 8 also serve to receive lead plugs as required to accurately, dynamically, and statically balance the mandrel 1. A similar group of holes are provided in flange 4 for similar use in balancing.

The mandrel 1 is arranged for rotation on bearing cage 10 at one end, and on bearing cage 11 at the opposite end. Bearing cages 1i) and 11 are each provided with several ports MA and 11A respectively, for ingress and according to the temperature of the operating conditions and the horsepower of the prime mover, and may be air, circulating water, or oil.

In tie preferred form of the invention shown in FIG flow vane fan assembly 12, comprising a motor, and a fan, and a housing having a deflected portion 13, direct ing the air through a' plurality of axial slots 14, through an annulus for-med between theouter tubular housing 16 of the prime mover and the inner'wall of the m'andrel 1. I

i URE 1 air enters through ports 11A flowing into'an axial. r

This oil drains via tube 400 into a central bore 40D in the motor shaft 21. and flows through to lubricate bearing 23 an'd by tube 46E to bearing 30. A second portion of the gear housing 44 is secured to 40 by bolts 45 and sup- The annulus is a space between a stationary wall 16 I and the rotating wall 1. This feature, cooperating with the fan, produces an axial turbulent' scrubbing type of air circulation (or water or other medium if employed),

to extract from and through this annulus the'rnaximum amount of heat. In theannulus the total outside diameter of the motor shell has been machined with a threading tool at 17A to create extended surface area.

Coolant can pass through the annulus 15, and through passages 18 surrounding a reduction gear. These passages are of larger cross sectional area than the annulus, since the gear reduction housing is preferably approxi: mately elliptical in shape, ratherthan circular. ant continues through, and exits through the ports 10A. If a liquid coolant is used rather than oil, the motor, reduction gear, etc, are tightly sealed to prevent the liquid entering them, the fan is omitted, and the flow is regu- 20 The cool- I lated in volume so as not to unbalance the rotation of the mandrel. g

The prime mover 19 is preferably an AC. squirrel cage motor with a rotor 29 built on to a tubular shaft 21 that is coaxial with the mandrel 1 and is journalled on ball bearings 22 and 23 with seals 22A and 23A. Bearing 22 a The motor stator is held from rotation by a tubular support or torque tube 25 into which is assembled the axial flow fan assembly 12. This torquetube varies in length according to the length of the mandrel and bristle assembly which is in the order of from 72" to 120" in overall length.

The torquetube 25 is secured to a fixed mounting or carrier. This has a rim portion 27 on which this torque tube 25 seats and a wall portion 28 with ports for air circulation and a shaft portion 29 which carries'the ball bearing 30. Suitable double lip seals 31 and 32 are provided.

Since shaft 29 and associated. carrier parts are secured to torque tube 25 which in turn is secured to the tubular housing or wall' 16, these parts are non-rotating, and the mandrel .1 rotated at this end on bearing over shaft portion 29 as a fixed shaft. Shaft portion 29 is tubular and has a threaded plug 54A in one end thereof. The leads from motor 19 and the leads from axial flow fan motor egress through tubular portion of 29 for connection to power source. The portion 29 is mounted in a mounting block 29A to which it is keyed by key 29B.

At the gear end of the prime mover. is a reduction gear comprising a first pinion or gear 33 which" is preferably an integral part of shaft 21. A countershaft 34 is designed as a cluster, one portion being. a pinion 35 meshing with pinion 33. Another portion is a pinion 36 meshports bearings 46 and 47 for shaft'38; vShaft 38 is drilled and flared, coaxial with shaft 48 which-is closed with a threaded plug 54. This passage isfo-r filling or drainage of lubricant by lube gun or suction. The gear case lubricant will also provide lubrication for the ball bear- ,ingsand spline connection.

The rotatable driveshaft 3 8 ends at spline 39. Qty axially, but. spaced therefrom is shaft 48 fixed against rotation by block 49-whichis of the same design as 29A both being rectangular and each bored and keyed onthe centerline, and each with twocavities. Shaft 48 extends within and out of themandrel, and supports part 10 for rotation on bearings50 and 51 within the mandrel. These bearings are double lip sealed by seals 52.

The scratch brush assembly is a self-contained'unit and I only'the non-rotatable shafts at each end project beyond the overalllength of the brush and flanges. These shafts maybe mounted on suitable slide and provided with screws .of hydraulic cylinders for applying brush pressure against the work rolls in the preferred amount of pressure or'inisalignment desired; while at the times the internal mechanism is maintained in line, and can be suitably ventilated and cooled.

ing with a pinion 37. Pinion 37 is integral'with a rnain noted The assembly contains four gears, a male and female spline and nine ball bearings which are all lubricated from one central oil supply in the gear case thus eliminating grease-lubrication which is an advantage since oil runs cooler than grease. V V FIGURES 3 and 4 show the method of mounting the brush roll at the ends thereof.

A rectangular frame 101 suitably bolted together, has two slots 102 and 103: for receiving trunnions 102A, 103A from part 29A or 49 (FIG. 1) in a manner that permits part 2A or 49-to position itself according to how the brush face may be misaligned with the work roll face. Part 29A (and 49) has upper and lower cavities and is connected in the lower cavity with a clevis 104 to a hydraulic cylinder 105 having a body clevis 106 secured to frame 101. The part 29A has a gasketed cover plate 107 over the other cavity containing the motor terminals, and in thiscavity the motor leads. can be connected to power source such as a flexible conduit 108 which will compensate for movement of part 29A or 49 in the frame 101. The motor leads come out only at part 29A so that one cavity in part 49 is not used. I

Frame 101 is secured to a structural frame to support the brush for rotation and adjustment.

An alternate type of mounting is shown in FIGURE 5. The assembly as shown in FIGURE 3 is mounted in a sub-frame 110 surrounding it, and supported therein by trunnionsrlltlA, 110B with ball bearings, and a rocker shaft 112 in bearings 113 which are secured. to a structural frame 114 for rotation and adjustment. Oneof these frames is connected to an eccentric drive (not shown) which can be actuated to rock the whole assembly axially to give a horizontal axial reciprocating brush action againstthe work rolls. 7

It is of'utmost importance to suitVopera-ting conditions that the brush diameter be kept to a minimum and normally in the order of 14- to 15" in diameter. The length 5 of the br'ush'is on theor'der of from 66" to long to su t the production requirements of the aluminum sheet.

The main tubular membenthere'fore, is designed with a heavy wall for minimum deflection" in operating conditio'ns, and to permit'maximum adjustment in the pressure of the bristles against the work-drum without distortion of the tubular member.. The bristles in the brush are usually .014 dia. high tempered wire, and the bristles are assembled in the brush extremely close together, giving a brush of great density. Since the brush is rotating at a speed much higher than the surface speed of the work rolls, and normally in opposite direction to them, it requires considerable horsepower and develops considerable heat.

The power required for a brush approximately 6 Wide, rotating at 3,000 f.p.m. is on the order of 25 HP. Since the brush is only 14 to 15" in diameter and is mounted on a heavy wall tube, the inside diameter of the tube to receive the motor is relatively small. The problem has been to pack HP. or more into a minimum of diameter and still have a passage left for clearance and ventilation for the removal of the heat from the motor. Incorporated in the motor structure is a high capacity axial flow fan, with its own special motor, so designed to force the air through the annulus between the motor and tube. The motor assembly is held stationary within the tube and the power takeoff shaft of the motor transmits the power through suitable coaxial reduction gearing to drive the rotating tube at the desired peripheral speedfrom 700 to 900 r.p.-rn.

The motor assembly is water-tight so that if desired, the axial flow fan can be omitted, and a stream of Water for cooling can be passed through the tube (via the two hollow shafts) to keep the motor and reduction gearing cool. The sealing arrangement being so designed as to isolate all bearings, gears, spline, wiring, etc., from water or oil if used as coolant. Some cooling comes from the flooded operation of the brush itself. As it has heretofore been mentioned, a stream of as much as 500 gallons of water a minute is on these brushes and this, of course, keeps the bristles cool and keeps the temperature of the tube itself at a low point; something on the order of 135. It is also possible to cool this motor by putting compressed air through the tube and around the motor, entering the air and taking it out via the same hollow shafts. Supplementing the cooling by the axial fiow fan, and/ or air or water flow, the motor itself, can be specially insulated to safely operate at temperature up to 300 F. Note that it is even possible to pump lube oil through all the bearings and gear reduction via the removable plug on the ends. In the taps for these plugs eyebolts can be inserted for lighting.

It will be seen from the foregoing description that this assembly comprises a permanently aligned mechanism and that the alignment of the motor in relation to the tube and the speed reducer is not affected by the alignment, or misalignment of the brush assembly to conform with the work roll face. The adjustment of the brush bristles to the Work roll face can be either on sliding blocks or on a suitable frame that can pivot, thus swinging the motor through an arc. No misalignment of the internal parts of this mechanism is possible by the adjustment of the brush to the work roll face.

I claim:

1. A brush assembly comprising a tubular mandrel, a bristle assembly secured to the mandrel, a prime mover means mounted Within the tubular mandrel, said prime mover having a stator and a driven shaft, speed transforming means mounted within the mandrel and connecting the prime mover driven shaft drivably to the mandrel, end bearing means supporting the mandrel rotatably at its ends, a tubular support within the mandrel connected at one end to the bearing means at one end of the mandrel, a prime mover housing within the mandrel and carrying the prime mover stator and fixed at one end to the other end of said tubular support, a tubular gear housing Within the mandrel and connected at one end to the prime mover housing, said gear housing containing said speed transforming means, said tubular support, prime mover housing and gear housing together forming a fixed tubular member, bearings mounted in said fixed tubular member carrying the prime mover 6 driven shaft, said speed transforming means including an output shaft, and bearings carried by said fixed tubular member and carrying said output shaft rotatably.

2. A rotary tool assembly comprising a tubular mandrel, cleaning means secured to the mandrel, an electric motor mounted within the tubular mandrel, said electric motor having a stator and a driven shaft, a speed reduction gear mounted Within the mandrel and connecting the electric motor driven shaft drivably to the mandrel, end bearing means supporting the mandrel rotatably at its ends, a tubular support within the mandrel connected at one end to the bearing means at one end of the mandrel, an electric motor housing Within the mandrel and fixed at one end to the other end of said tubular support, an electric motor in the electric housing, a tubular gear housing within the mandrel and connected at one end to the electric motor housing, said gear housing containing said speed reduction gear, said tubular support, motor housing and gear housing together forming a fixed tubular member spaced radially from the mandrel, said speed reduction gear including an output shaft, and bearings carried by said fixed tubular member and carrying said output shaft rotatably, a bearing member located within said fixed tubular member, a first bearing carried by said bearing member and supporting one end of the motor driven shaft, a second bearing carried by the gear housing and supporting the other end of the motor driven shaft, end bearing cages fixed to the mandrel at the ends thereof and mounted on said end bearing means respectively, one of said end bearing means having two bearings spaced apart Within and carrying the adjacent end cage.

3. A rotary tool assembly comprising a tubular mandrel, cleaning means secured to the mandrel, an electric motor mounted within the tubular mandrel, said electric motor having a stator and a driven shaft, a speed reduction gear mounted Within the mandrel and connecting the electric motor driven shaft drivably to the mandrel, hearing means supporting the mandrel rotatably at its ends, a tubular support within the mandrel connected at one end to the bearing means at one end of the mandrel, an electric motor housing within the mandrel and fixed at one end to the other end of said tubular support, an electric motor within said electric motor housing, a tubular gear housing within the mandrel and connected at one end to the motor housing, said gear housing containing said speed reduction gear, said tubular support, motor housing and gear housing together forming a fixed tubular member, bearings mounted in said fixed tubular member carrying the electric motor shaft, said speed reduction gear having an output shaft, a countershaft having pinion teeth on each end thereof, pinion teeth on the motor shaft meshing with the pinion teeth on one end of the countershaft, pinion teeth on said output shaft meshing with the pinion teeth on the other end of the countershaft, splines on the output shaft, internal splines on one of said cages engaging the splines 0n the output shaft, and bearings carried by said fixed tubular member and carrying said output shaft rotatably.

4. An internally powered scratch brush as claimed in claim 3 wherein an axial flow vane fan assembly is mounted in the tubular support.

5. A brush assembly comprising a tubular mandrel, a bristle assembly secured to the mandrel, an electric motor mounted within the tubular mandrel, said electric motor having a stator and a driven shaft, a speed reducing gear connecting the motor driven shaft drivably to the mandrel, end cages secured to the ends of the mandrel respectively, bearing means supporting the end cages rotatably, a tubular support within the mandrel, a mo tor housing within the mandrel containing the motor and fixed at one end to the other end of said tubular support, a tubular gear housing within the mandrel and connected at one end to the motor housing, said gear housing containing said speed reduction gear, said tubur 3;? lar support, motor housing and gear housing-together forming a fixed tubularmember spaced radially from f the mandrel, hearings mounted in said fixed tubular mem- 4 her carrying the motor shaft, said speed reduction gear 'havingan output shaft, bearings carried by said fixed tubular member and carrying said output shaft rotatably,

openings in ,said cages, a fan Within said tubularsupv the slots. 1

port, and openings in the tubularsupport, whereby the fan draws. air in through the openings in 'one cage and impels it through the openings in the tubular's uppo'rt then through the space between the tubular support and the mandrel, and out through the openings in the other cage.

6. A scratch brush as jclaimed-in claim 1, having oil seals at the ends of the prime mover shaft between the shaft and the fixed tubular jmember, a reservoir adjacent the speed transforming means, in which oil flung off by the gears is caught, a tube conducting oil from the reservoir into the motor shaft which is tubular so that the oil can pass into the shaft at one end thereof through the seal of the other end thereof, and means to conduct the mandrel and said'frames having slots to receive said,

trunnions, said trunnions being positioned in a horizontal plane and mounted in the slots for vertical movement and means for each frame connecting the frame adjustnbly to the adjacent trunnions, said meansbeing adjustable radially of the mandrel'to adjust the trunnions along the oil leaving the shaft to the adjacent end bearing means. 7 r

7. A brush assembly comprising a tubular mandrel,

a bristle assembly secured to the mandrel, a prime mover means mounted within the tubular mandreL'speed transforming means connecting the prime mover drivably to the mandrel, bearing means supporting the mandrel rotatably at its ends, shafts carrying said bearing means, trunnions on the shafts, two frames one at each end of the mandrel and said frames having slots to'receive said trunnions, said 'trunnions being positioned in a horizontal plane and mounted in the slots for vertical movement and means for each frame connecting the frame adjjust the slots, two shafts mounted one at each end of the mandrel, trunnions on each frame at'right angles to the bearing means trunnions, brackets on each shaft carrying the frame trunnions.

References Cited by the Examiner V UNITED STATES PATENTS 1,480,542

1/24 Brown 15-213 X 1,678,064 7/28 Jones etal. IS-21.3 1,770,643 7/ 30 Giambertoni 15-49. 2,281,256 4/42 Bargfeldt et al. 15-77 2,856,624 10/58 Cook et'al. 15-181 3,084,367 4/63, ,Radinse 15-181 FHOREIGN PATENTS j 846,333' 8/52 Germany.

CHARLES A. \VILLMUTH, Primary Examiner.

Claims (1)

1. A BRUSH ASSEMBLY COMPRISING A TUBULAR MANDREL, A BRISTLE ASSEMBLY SECURED TO THE MANDREL, A PRIME MOVER MEANS MOUNTED WITHIN THE TUBULAR MANDREL, SAID PRIME MOVER HAVING A STATOR AND A DRIVEN SHAFT, SPEED TRANSFORMING MEANS MOUNTED WITHIN THE MANDREL AND CONNECTING THE PRIME MOVER DRIVEN SHAFT DRIVABLY TO THE MANDREL, END BEARING MEANS SUPPORTING THE MANDREL ROTATABLY AT ITS ENDS, A TUBULAR SUPPORT WITHIN THE MANDREL CONNECTED AT ONE END TO THE BEARING MEANS AT ONE END OF THE MANDREL, A PRIME MOVER HOUSING WITHIN THE MANDREL AND CARRYING THE PRIME MOVERR STATOR AND FIXED AT ONE END TO THE OTHER END OF SAID TUBULAR SUPPORT, A TUBULAR GEAR HOUSING WITHIN THE MANDREL AND CONNECTED AT ONE END TO THE PRIME MOVER HOUSING, SAID GEAR HOUSING CONTAINING SAID SPEED TRANSFORMING MEANS, SAID TUBULAR SUP-

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