US2097282A

US2097282A - Mechanical driving mechanism

Info

Publication number: US2097282A
Application number: US721078A
Authority: US
Inventors: Albert T Keller
Original assignee: Bethlehem Steel Corp
Current assignee: Bethlehem Steel Corp
Priority date: 1934-04-18
Filing date: 1934-04-18
Publication date: 1937-10-26
Anticipated expiration: 1954-10-26

Description

Oct. 26, 1937. A. 'r. KELLER 2,097,282

' MECHANICAL DRIVING MECHANISM Filed April 18, 1934 2 Sheets-Sheet 1 Oct. 26, 1937. A. T. KELLER 2 2,097,282

MECHANICAL DRIVING MECHANISM Filed April 18, 1954 2 Sheets-Sheet 2 v I Z; n

gnvcntoz @672 ZIllair Patented Oct. 26, 1937 UNITED STATS MECHANICAL DRIVING MECHANISM Albert T. Keller, Bethlehem, Pa., assignor to Bethlehem Steel Company, a corporation of Pennsylvania Application April 18, 1934, Serial No. 721,078

1'7 Claims.

This invention relates to the drive of a rolling mill by which the mill is reversed while the prime mover driving it maintains its revolution in a given direction. It is particularly useful in 5 connection with sheet or tin plate mills where frequent reversals are desirable, which for economy must be performed in the shortest possible interval of time. Hitherto in rolling mills reversal has been accomplished by reversing the electric motor driving the mill, by reverse gearing or by other means which in general are not suitable for the very rapid reversals corresponding to the short passes of sheet and tin plate mills. For this reason such mills are run con- ]5 tinuously in one direction, the work after a pass being carried over the top of the rolls and given the next pass in the same direction. In the present invention a friction drive is employed which is preferably arranged to drive both rolls simultaneously. The friction drive is designed with power to transmit the heavy torques required for rolling and at the same time is arranged so that a small movement of certain of the parts suffices to bring about a reversal, the power for causing this movement preferably being furnished by hydraulic cylinders. At the time of reversal a certain amount of slip must take place between the friction elements in order to accelerate the rolls. These elements must be of such a character that they can slip with a minimum of damage under heavy pressure, can be readily redressed to correct for unequal wear and are simple and relatively cheap to replace.

Referring to the drawings:

Fig. 1 is a side elevation showing one embodiment of the reversing mechanism connected to drive the rolls of a sheet mill; Fig. 2 is an end elevation partly in section of the reversing mechanism shown in Fig. 1; Fig. 3 is a diagrammatic drawing of the piping arrangements for controlling the mechanism.

In the drawings H and I2 are rolls of a sheet mill positioned in housing l3 and driven by spindles l4 and I5 through universal couplings i5 and H. These spindles in turn receive their drive from shafts l8 and I9 of reversing mechanism 20. This mechanism comprises the four drums 2|, 22, 23, and 24 held in bearings in housing members 25. The shaft of drum 2| is provided with Wobbler 26 which receives a drive continuously in the direction of the arrow from an outside source of power and is mounted in relatively fixed journal bearing blocks, one of which is shown at 21, supported by the housing but adapted for adjustment horizontally in a.

direction transverse to the drum axis. 22 indicates a driven idler drum likewise held in relatively fixed journal bearing blocks one of which is shown at 28 and which are also adapted for adjustment in the housing, is pressed in frictional driving contact with drum 2|, a heavy surface pressure between the two drums being maintained by screws 29 threaded in the housing and pressing against the outer surfaces of bearing blocks 21 and 28. Drum 23 is held in bearingblocks one of which is shown at 39. These can be moved horizontally in the housing transversely of the drum axis by means of stems 3| integrally attached to the bearing blocks and actuated longitudinally by pistons 32 and 33 in

fluid pressure cylinders

34 and 35, which latter are rigidly attached to the housing. Drum 23 may thus be brought either into surface driving contact with drum 22 as shown in the drawings or, by moving the bearing block to the left into contact with drum 2|, the direction of revolution in the former case being clockwise on Fig. 2 and in the latter counterclockwise. By actuating the fluid pressure cylinders so as to position the drum half way between the right and left hand positions the driving connection will be entirely broken. Stems .3l serve not only to transmit the thrust of the pistons to the bearing blocks but to support the weight of the blocks and drum as well, seats as shown at 36 being provided for the stems to slide on.. The upward thrust of the drum when in the driving positions is taken by the surface 31, and a similar surface on the other housing member.

Lower drum 24 is held in bearing blocks one of which is shown at 39. These can be moved horizontally in the housing transversely of the drum axis by means of stems 40 one of which presses against each side of each of the bearing blocks. The stems are integral with pistons M and 42 of

fluid pressure cylinders

43 and 44 which are rigidly attached to the housing. This drum like drum 23 may thus be brought into driving contact with drum 2| or the driven idler drum 22 or may be brought to a neutral position where the driving connection is broken. Bearing blocks 39 are supported by a flat surface shown at 45 and a similar surface on the other housing member, these surfaces serving also to take the downward thrust when the drum is in the driving positions.

Housing members 25 are made with body portions 45 and caps 41 fastened by bolts 48. By releasing these bolts and removing the caps the drums and their bearings may be lifted out for regrinding or replacement.

In Fig. 3 is shown diagrammatically a suitable arrangement of valves and pipe for controlling the fluid pressure cylinders. The two cylinders 34 by which drum 23 is forced to the right in Fig. 2 are connected to pipe 5!, while the two cylinders 44, by which drum 24 is forced to the left are connected to pipe 52, cylinders 35 by which drum 23 is forced to the left are connected to pipe 53 and cylinders 43 by which drum 24 is forced to the right are connected to pipe 54. In this manner of arrangement the pressure of the cylinders upon each side of the housing is balanced or equalized. Pipes 5! and 52 unite in the common pipe while

pipes

53 and 54 unite in the common pipe 56. Valve 51 shown diagrammatically is arranged to connect pipe 55 with pipe 58, to a source of high pressure fluid, and pipe 56 with drain pipe 59 or alternatively to connect pipe 55 with pipe 59 and pipe 56 with pipe 58, handle 60 causing the shift from one condition to the other. In the intermediate position of the handle, flow is cut off from pipes 55 and 56. In one extreme position of the handle the upper drum will be forced to the left and the lower drum to the right, in the other extreme position the opposite movement will take place, while in the intermediate position the drums can be held in any desired relation. Valves 6! are placed in the pipes leading to each cylinder to correctly apportion the flow to and from each of them and to permit individual operation of any cylinder or group of cylinders.

A typical example of the operation of this mill in producing tin plate is as follows. Two lengths of tin bar delivered from the heating furnace are passed in succession through the rolls with the drive set in the forward direction. The drums of the reversing gear are then shifted to the neutral position, held there for a moment while the friction in the roll and drum necks brings the rolls to a stop. The drums are then shifted to the further extremity causing the rolls to drive in the reverse direction, the partially rolled bars are fed back through the rolls in reverse order. This back and forth rolling is continued, the bars being matched when properly reduced in thickness, and finally the pair is removed from the rolls, doubled, reheated and the rolling process repeated.

In this process the work of the catcher, whether a man or machine is employed for the purpose is very slight and can be performed rapidly. Moreover the reversing cycle may be made very short. Assuming a speed of 35 R. P. M. on the rolls of an ordinary sheet or tin mill and a coefiicient of friction on the bearings of 10% the drive with spindles and rolls will stop in about 1 seconds by simply breaking the contact between the friction drums. To bring the spindles and rolls from rest up to 35 R. P. M. with a pressure of 80,000 pounds between the friction drums will require about the same period. If the actual time of the pass is of a second the total time for a pass and reversal will be about 3 seconds, or 18 cycles per minute. With a skilled operator who knows how much drifting takes place under varying conditions of draft, the number of cycles can be increased by disengaging the friction drums before the end of a pass and allowing the bar or sheet to slow the rolls nearly to rest'as they completethe pass. The friction drums may also be thrown into a reverse driving position before the rolls have come completely to rest.

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

1. In a mechanical drive, a first drum, means to drive said first drum from an external source of power, a second drum, means to hold said first and said second drums in rolling contact,

third and fourth drums, selective means to force said third drum into rolling contact with said first drum and said fourth drums into rolling contact with said second drum or said third drum into rolling contact with said second drum and said fourth drum into rolling contact with said third drum, and driven means operatively connected with said third and said fourth drums.

2. In a rolling mill drive, a housing, a first drum, bearings for said first drum slidably held in said housing, a second drum, bearings for said second drum slidably held in said housing, adjustable means pressing against said bearings to force said first and second drums into rolling contact, a third drum, bearings for said third drum slidably held in said housing, controllable means pressing against said last mentioned bearings to force said third drum into rolling contact with said first drum and with said second drum respectively, a fourth drum, bearings for said fourth drum slidably held in said housing, and controllable means pressing against said last mentioned bearings to force said fourth drum into rolling contact with said first drum and with said second drum respectively.

3. In a rolling mill drive, a housing, a first drum, bearings for said first drum slidably held in said housing, a second drum, bearings for said second drum slidably held in said housing, adjustable means pressing against said bearings to force said first and second drums into rolling contact, a third drum, bearings for said third drum slidably held in said housing, controllable means pressing against said last mentioned bearings to force said third drum into rolling contact with said first drum and with said second drum respectively, a fourth drum, bearings for said fourth drum slidably held in said housing, controllable means pressing against said last mentioned hearings to force said fourth drum into rolling contact with said first drum and with said second drum respectively, and means for simultaneously actuating said first mentioned and said second mentioned controllable means.

4. A reversing drive, comprising a driving drum and a driven idler drum. adapted to be held in frictional contact therewith, relatively fixed journal bearings for the driving drum and the driven idler drum, a. pair of driven drums mounted in movable journalbearings, fluid pressure means for alternately moving the pair of driven drums simultaneously into frictional engagement under pressure with the driving drum and the driven idler drum, and means for holding the pair of driven drums in a neutral position out of engagement with the driving drum and the driven idler drum.

v 5. A reversing drive, comprising a driving drum and a driven idler drum. adapted to be held at all times in frictional contact with each other, relatively fixed journal bearings for the driving drum and the driven idler drum, a pair of driven drums mounted in movable journal bearings, and fluid pressure means for alternately holding one of the pair of driven drumsinfric tional engagement with the driving drum and the other in frictional engagement with the driven idler drum. 1

6. A reversing drive, comprising a driving drum and a driven idler drum frictionally engaging each other mounted in relatively fixed journal bearings, a pair of driven drums mounted in movable journal bearings engaging the driving drum and the driven idler drum, and fluid pressure means connectedto themovable journal bearings adapted to alternately force each of the pair of driven drums simultaneously in opposite directions into engagement with the driving drum or the driven idler drum.

7. A reversing drive, comprising a housing, a driving drum and a driven idler drum frictionally engaging each other and mounted in relatively fixed journal bearings in the housing, a pair of driven drums mounted in movable journal bearings in the housing each adapted to frictionally engage the driving drum or the driven idler drum on opposite surfaces, slideways formed in the housing for the movable journal bearings, fluid pressure means for simultaneously forcing one of the said pair of driven drums into frictional engagement with the driving drum and the other into frictional engagement with the driven idler drum, and fluid pressure means for simultaneously reversing the positions of the pair of driven drums to force the one engaging the driving drum into frictional engagement with the driven idler drum and the other into frictional engagement with the driving drum.

8. A reversing drive, comprising a housing, a driving drum and a driven idler drum frictionally engaging each other and mounted in relatively fixed bearing blocks in the housing, means for adjusting the relatively fixed bearing blocks, a pair of driven drums mounted in movable bearing blocks each adapted to frictionally engage the driving drum or the driven idler drum on opposite surfaces, slideways formed in the housing for the movable journal bearing blocks, fluid pressure means for simultaneously reciprocating the movable journal bearing blocks to force one of the pair of driven drums into frictional engagement with the driven idler drum, and means for controlling the fluid pressure to reverse the positions of the pair of driven drums in their relation to the driving drums and the driven idler drum.

9. A reversing drive, comprising a housing, a driving drum and a driven idler drum mounted in relatively fixed journal bearings in the housing and frictionally engaging each other, means for adjusting the relatively fixed journal bearings, a pair of driven drums mounted in movable journal bearings each adapted to alternately engage the driving drum or the driven idler drum on opposite surfaces, slideways formed in the housing for the movable journal bearings, a piston on opposite sides of each movable journal hearing, a fluid pressure cylinder for each piston, and means for controlling the fluid supply to the cylinders for simultaneously reciprocating the movable journal bearings for one of said pair of driven drums in the reverse direction to that of the other one of said pair of driven drums.

10. A reversing drive, comprising a driving drum and a driven idler drum adapted to be held in frictional contact by relatively fixed journal bearings, a pair of driven drums mounted in movable journal bearings adapted to alternately frictionally engage the driving drum. and

theidriven idler. drum, and means for simultaneously sliding the movable journal bearings for each of the pairzof driven drumsin opposite directions;

11.,A reversing drive, comprising a housing, a driving drum and a driven idler drum horizontally disposed and adapted to be held in frictional contact by relatively fixed-journal bearings, an upperandlower driven drum mounted in movable journal bearings adapted to frictionally engage opposite surfaces of thedriving drum and the driven idler drum, slideways and seats formed in the upper portion of the housing, stems integrally connected to the movable journal bearings and slidably mounted in the seats for supporting the movable journal bearings for the top driven drum, a piston formed on the outer end of each stem, a fluid pressure cylinder for each piston secured to the side of the housing, slideways formed in the lower portion of the housing for supporting the movable journal bearings for the lower driven drum, stems slidable in the housing for engaging opposite sides of the movable journal bearings for the lower driven drum each having a piston formed on their outer end, fluid pressure cylinders for said pistons secured to the housing, and means for controlling the fluid pressure to and from the cylinders.

12. In a mechanical drive, a first drum, means to drive said first drum from an external source of power, a second drum, relatively fixed journal bearings for holding said first and said second drums in rolling contact, a third drum, means to force said third drum alternately into rolling contact with said first and with said second drums respectively, a fourth drum, and means operated simultaneously with the operating means for the third drum to force said fourth drum alternately into rolling contact with the second and said first drums respectively.

13. A reversing drive, comprising a driving drum and a driven idler drum each mounted in relatively fixed journal bearings and frictionally engaging each other, a pair of driven drums mounted in movable journal bearings adapted to frictionally engage the driving drum and the driven idler drum in alternate relation to each other, and means for simultaneously reciprocating the movable journal bearings for one of the pair of driven drums in opposite directions to that of the other driven drum.

14. A reversing drive, comprising a driving drum and a driven idler drum held in frictional contact with said driving drum, relatively fixed bearings for the driving drum and the driven idler drum, a pair of driven drums mounted in movable journal bearings each adapted to alternately frictionally engage the opposite surfaces of the driving drum and the driven idler drum, and fluid pressure means for holding the pair of driven drums in frictional contact with the driving drum and the driven idler drum.

15. A reversing drive, comprising a driving drum and a driven idler drum adapted to be held in frictional contact with the driving drum, relatively fixed bearings for the driving drum and the idler driven drum, means for adjusting the relatively fixed bearings for the driving drum and the driven idler drum, a pair of driven drums mounted in movable journal bearings each adapted to alternately frictionally engage the driving drum and the driven idler drum, and fluid pressure means for simultaneously reciprocating the movable journal bearings for each of the pair of driven drumsin opposite directions.

16. A reversing drive, comprising a driving drum, an idler drum adapted to frictionally engage the driving drum, fixed bearings for the driving drum and the driven idler drum, and a pair of driven drums each mounted in oppositely movable journal bearings each adapted to simultaneously alternately engage and be driven by the driving drum and the driven idler drum.

1'7. A reversing drive, comprising a driving ALBERT T. KELLER.