US3786546A

US3786546A - Forming roll, especially for rod mills and the like

Info

Publication number: US3786546A
Application number: US00294194A
Authority: US
Inventors: T Brown; J Huber
Original assignee: Kennametal Inc
Current assignee: Kennametal Inc
Priority date: 1972-10-02
Filing date: 1972-10-02
Publication date: 1974-01-22
Anticipated expiration: 1991-01-22
Also published as: DE2349498C3; AU6087973A; AU467971B2; LU68539A1; JPS4993264A; IT993960B; FR2201137B1; ZA737555B; GB1418225A; FR2201137A1; DE2349498A1; ES419179A1; CA975592A; DE2349498B2; JPS5518562B2

Abstract

A forming roll of hard material, such as cemented tungsten carbide, is mounted on a driving shaft. The shaft has a shoulder either integral with the shaft or in the form of a nut threaded thereon abutting one axial end of the roll while the other end of the roll is in the form of a wide angle ''''V.'''' A keying element is mounted on the shaft having a wide angle ''''V'''' configuration complementary to that of the roll, and this last mentioned element is keyed to the shaft for transmitting torque from the shaft to the roll.

Description

United States Patent [191 Brown et a1.

[ Jan. 22, 1974 FORMING ROLL, ESPECIALLY FOR ROD MILLS AND THE LIKE [73] Assignee: Kennametal lnc., Latrobe, Pa.

[22] Filed: Oct. 2, 1972 [21] Appl. No.: 294,194

Rackoff et al. 29/125 Strandel 29/125 X Primary ExaminerAlfred R, Guest Attorney, Agent, or Firm-Melvin A. Crosby 5 7 ABSTRACT A forming roll of hard material, such as cemented tungsten carbide, is mounted on a driving shaft. The shaft has a shoulder either integral with the shaft or in the form of a nut threaded thereon abutting one axial end of the roll while the other end of the roll is in the form of a wide angle V. A keying element is mounted on the shaft having a wide angle V" configuration complementary to that of the roll, and this last mentioned element is keyed to the shaft for transmitting torque from the shaft to the roll.

13 Claims, 5 Drawing Figures PAIENT M22 1974 SHEET 1 BF 3 y mm PAIENTEDJAN 22 m4 SHEET 2 BF 3 FIG-2 FORMING ROLL, ESPECIALLY FOR ROD MILLS AND THE LIKE The present invention relates to forming rolls and to the connection of such forming rolls to supporting shafts, especially for use in connection with rod mills and the like.

Rod mills are well known and consist of a frame having a plurality of pairs of driven rolls through which the material being treated is passed for forming operations. Two mills operate in substantially the same manner and, also, utilize a plurality of pairs of driven rolls.

The forming of the material is accomplished by shaping the rolls so as to have contoured grooves therein which progressively shape the member passing therethrough to the desired cross sectional configuration and size. The treatment of the work member might take the form of imparting a certain cross sectional shape thereto or it might take the form of reducing the size thereof.

The work load on the forming rolls is extremely heavy and it is important that the rolls be firmly supported on the drive shafts therefor and firmly keyed thereto.

Due to the extreme pressures under which rolls operate and the stress is built up therein, cemented tungsten carbide forms a preferred material because of its strength and resistance to wear. Cemented tungsten carbide forming rolls, however, present particular problems in that the rolls are preferably mounted without any substantial amount of tensile stress being developed therein. Rather, it is preferable to preload the rolls in compression, at least the sides thereof, thereby to minimize the deflection of the rolls and to minimize the chance of breaking the rolls.

Still further, cemented tungsten carbide forming rolls present problems in respect of the manufacture thereof because the material is quite expensive and can only be extensively machined in the green state. In the green state, which is the form which cemented carbide takes following compacting and presintering thereof and prior to the final sintering, the workpieces can be machined, but are quite fragile and can easily crack and develop flaws which will appear in the final sintered product. Any such crack or flaw in the finally sintered product'is a fatal defect and will cause the work member to be scrapped.

With the foregoing in mind, the present invention has as a particular objective the provision of an improved forming roll and an improved mounting therefor on a supporting shaft.

A further object is the provision of a forming roll formed of cemented hard metal carbide material which is relatively simple to machine without creating an undesirable amount of scrap.

These and other objects and advantages of the present invention will become more apparent upon reference to the following detailed specification taken in connection with the accompanying drawings in which:

FIG. 1 is a fragmentary view showing one form of roll according to the present invention and a mounting arrangement therefor.

FIGS. 2, 3 and 4 show different mounting arrangements.

FIG. 5 is a perspective view showing the manner in which a roll interlocks with an abutment type keying ring.

BRIEF SUMMARY OF THE INVENTION:

According to the present invention, forming rolls, or roll members, of a hard wear resistant material such as a cemented hard metal carbide and, especially, cemented tungsten carbide, are made which have straight cylindrical bores therethrough and one end disposed in a plane at an angle to the axis of the bore, preferably, a right angle. The other end of the roll is formed to a wide angle wedge shape. The roll is mounted on a shaft with a shoulder or nut abutting the plane side of the roll while a wedge shaped key ring abuts the wedge shaped side of the roll.

The roll is clamped on the shaft between the key ring and a shoulder on the shaft, or a nut threaded on the shaft abutting the other side. The roll is thus held in compression during working operations. The forming of the roll with the wide angle V" shape on the one side simplifies and makes more expensive the manufacturing of the roll while, at the same time, permitting adequate torque to be transmitted from the drive shaft into the roll.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1, 10 is a support shaft and has mounted thereon in spaced relation a pair of forming rolls, or roll members, 12 and 14, each of which is formed ofa hard wear resistant material, such as cemented hard metal carbide, especially tungsten carbide. Each roll on the side facing the other has a wedge shaped end, 16 on roll 12, and 18 on roll 14. Each wedge shaped edge is engaged by a

respective ring

20, 22 having a corresponding wedge shape thereon. In the drawings, the wedge shape on the rings is concave, but it is possible to make the wedge shape on the rolls concave.

The rings have respective undercuts 25, 26 disposed at the peak of the wedge shape on the carbide roll to prevent interference that might initiate fracturing of the roll. The

rings

20 and 22 abut opposite ends of an enlarged intermediate region 28 formed on shaft 10 and are locked against rotation on the shaft by a pair of

keys

30 and 32 mounted in axial slots provided in the enlarged diameter portion 28 of shaft 10 and having opposite end parts engaging notches 33 in the

rings

20 and 22.

The sides of the rolls facing away from each other are engaged by respective nuts 34, 36 which are threaded' into the shaft and pulled up tight against the rolls to clamp the rolls firmly in compression against their re spective abutment and keying rings.

FIG. 2 shows a modified arrangement in which a wedge shaped ring 40 is threaded on a shaft 42 and is firmly locked on the shaft by a set screw 44. Ring 40 engages one side of a carbide roll 46 having the side facing the ring wedge shaped so as to fit firmly against the ring while on the other side of the roll there is a nut 48 threaded on the shaft tightly against the roll and adapted for being locked in place on the shaft by a set screw 50.

In FIG. 3, the shaft 60 carries an abutting wedge shaped keying ring 62 fixedly secured to the shaft as by welding 64. A carbide roll 66 is mounted on the shaft and has one end engaging ring 62 while at the other end a nut 68 is threaded on the shaft and pulled up tight against the adjacent end of the roll and is locked in place on the shaft by a set screw 70.

In FIG. 4, the wedge ring 80 abuts a shoulder 82 on shaft 84 and is fixed to the shaft in a predetermined rotated position as by welding 86. This ring is engaged by one end of carbide roll 88 which has a wedge shaped configuration meshing with that of ring 80 while at the other end of the roll is engaged by a nut 90 threaded on the shaft and fixed in position thereon by a set screw 92.

FIG. 5 shows a typical roll 94 and a typical wedge ring 96. It will be seen that the end of roll 94 facing wedge ring 96 is formed to a true wedge shape by form ing the roll at the wedge shaped end so that the said end lies in two angularly related planes. The opposed end of the wedge ring is similarly formed so as to lie in two angularly related planes with an undercut 98 at the juncture of the planes so as to avoid the development of excessive pressure on the carbide at the peak of the V shape thereon.

In all of the illustrated and described modifications, it will be noted that the forming roll is relatively simple in configuration and that the drive region in the form of the wedge shape formed on end end of the roll can be machined thereon relatively easily while avoiding any sharp angled corners and without removing any great amount of material.

All of the machining operations which would be difficult to carry out on the forming rolls and which would lead to an undesired amount of scrap are performed on the supporting shaft and the wedge shaped drive rings which engage the wedge shaped sides of the forming rolls.

It will also be noted that the rolls are tightly clamped between opposing surfaces so that the forming rolls are maintained in a state of compression in the axial direction which contributes substantially to the resistance of the rolls to deformation when rotated in the radial direction by the work being operated.

The rolls are shown with simple peripheral configurations only thereon, but it will be understood that substantially any desired contour could be provided on the working surface of the roll.

From the foregoing, it will be seen that each roll, or roll member, is formed to have a wide angle wedge shaped driving surface at one end and an abutment surface at the other end. The driving surface is advantageously symmetrical about a central axial plane of the roll member while the abutment surface is preferably a surface of revolution about the axis of the roll member facing in the axial direction and, advantageously, a flat surface in a plane perpendicular to the axis of the roll member.

Modifications may be made within the scope of the appended claims.

What is claimed is:

l. A forming roll member comprising a body of hard wear resistant material, said body having a cylindrical central axial bore and an outer peripheral surface concentric with said bore, one end of said body formed with an annular abutment surface disposed at a right angle to the axis of said bore, and the other end of said body being wedge shaped with the apex thereof being disposed on a line perpendicular to and intersecting the axis of said bore, the said other end of the body on opposite sides of said apex being disposed in respective angularly related planes which intersect at said apex.

2. A forming roll member according to claim 1 in which said hard wear resistant material comprises a cemented hard metal carbide.

3. A forming roll member according to claim 1 in which said hard wear resistant material comprises cemented tungsten carbide.

4. In a rod mill; a shaft, at least one roll member of hard wear resistant material mounted on said shaft, a ring fixed to the shaft at one end of the roll member, said one end of the roll member and the end of the ring opposed thereto having a wide angle complementary wedge shape whereby said ring keys the roll member to the shaft, the other end of said roll member having an annular abutment surface disposed at a right angle to the axis of said shaft, and an abutment element on the shaft abuttingly engaging abutment surface at said other end of the roll member.

5. A rod mill according to claim 4 in which said abutment element is a nut threaded on said shaft and having the side facing said roll member complementary in shape to said abutment surface.

6. A rod mill according to claim 4 in which said ring is welded to said shaft.

7. A rod mill according to claim 4 in which said shaft comprises a shoulder engaging the side of the ring which faces away from said roll member.

8. A rod mill according to claim 7 in which said ring is welded to the shaft.

9. A rod mill according to claim 7 which includes a key fixed to the shaft and engaging said ring.

10. A rod mill according to claim 7 in which said shaft has axial slot means formed therein, and key means fixed in said slot means and engaging said ring.

ll. A rod mill according to claim 4 which includes two roll members on the shaft in axially spaced relation, said shaft having an enlarged diameter region between said roll members, a ring having one side abutting each end of the shoulder and the outer side abutting the adjacent inwardly facing end of the adjacent roll member, the said other side of each ring and the adjacent end of the pertaining roll member being formed to complementary wedge shapes, the outwardly facing end of each roll member facing away from the pertaining ring having an annular abutment surface disposed at an angle to the axis of said shaft, each abutment element comprising a nut threaded on the shaft and engaging the abutment surface of each roll member, and means fixing each said ring against rotation on said shaft thereby to key the respective roll member to the shaft.

12. A rod mill according to claim 4 in which said hard wear resistant material comprises cemented hard metal carbide.

13. A rod mill according to claim 4 in which said hard wear resistant material comprises cemented tungsten

Claims

1. A forming roll member comprising a body of hard wear resistant material, said body having a cylindrical central axial bore and an outer peripheral surface concentric with said bore, one end of said body formed with an annular abutment surface disposed at a right angle to the axis of said bore, and the other end of said body being wedge shaped with the apex thereof being disposed on a line perpendicular to and intersecting the axis of said bore, the said other end of the body on opposite sides of said apex being disposed in respective angularly related planes which intersect at said apex.

6. A rod mill according to claim 4 in which said ring is welded to said shaft.

8. A rod mill accoRding to claim 7 in which said ring is welded to the shaft.

11. A rod mill according to claim 4 which includes two roll members on the shaft in axially spaced relation, said shaft having an enlarged diameter region between said roll members, a ring having one side abutting each end of the shoulder and the outer side abutting the adjacent inwardly facing end of the adjacent roll member, the said other side of each ring and the adjacent end of the pertaining roll member being formed to complementary wedge shapes, the outwardly facing end of each roll member facing away from the pertaining ring having an annular abutment surface disposed at an angle to the axis of said shaft, each abutment element comprising a nut threaded on the shaft and engaging the abutment surface of each roll member, and means fixing each said ring against rotation on said shaft thereby to key the respective roll member to the shaft.

13. A rod mill according to claim 4 in which said hard wear resistant material comprises cemented tungsten carbide.