GB2171490A

GB2171490A - Improvements in or relating to a roll

Info

Publication number: GB2171490A
Application number: GB8531894A
Authority: GB
Inventors: Gunter Wolf
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-02-22
Filing date: 1985-12-30
Publication date: 1986-08-28
Also published as: DE3506182C2; JPS61192922A; GB8531894D0; JPH0258490B2; DE3506182A1; GB2171490B

Abstract

The roll comprises a rotating hollow shell (1) and a non-rotating beam (2) which extends through the shell (1) over the length thereof, projects from the shell ends and is mounted at one end (4) in a drive casing (8) by way of a bearing (5) permitting sagging of the beam (2). To secure the beam end (4) axially to the bearing (5) from outside the drive casing (8), a transverse pin (50) is provided which can be introduced and removed through a transverse passage (46) in the drive casing (8) and which engages in the beam end (4), so that the drive casing (8) with the ring flange (7) can be withdrawn from or pushed on to the beam end (4) as a whole, and secured thereon, without demounting. <IMAGE>

Description

SPECIFICATION Improvements in or relating to a roll THE INVENTION relates to a roll and more particularly to a roll comprising a stationary inner beam surrounded by a rotating hollow shell which is driven at one end.

Rolls of this kind are used in calenders and pressing machines in the paper industry for example, and are often up to 10 metres in length and up to 1 metre in diameter because of the considerable working widths of modern papermaking machines. Operating speeds are high and may be as high as 2000 metres/minute. Consequently, the power which the drive is required to transmit to such a roll is considerable and may amount to several hundred kilowatts. Providing sufficient space is available, there is no particular problem in devising transmissions capable of transmitting powers of this order.Unfortunately, space is often limited in the case of calenders and similar rolling devices and the drive must not have a radial overhang much greater than the roll diameter, while for the same reason the drive shaft cannot extend through an upright support element of the machine in a position substantially parallel to and adjacent the roll axis to engage the roll shell from the side, since this would similarly increase the radial dimension of the drive.

To satisfy these special constructional requirements, special drives have been developed for rolls of the type presently under consideration and one such roll, has been disclosed in US-PS 3 855 681. In the device disclosed in this prior specification there is a power division about a central drive wheel such that the power is divided between three pinion shafts distributed around the periphery of the drive wheel. The pinion shafts extend past the beam end bearing and the outputs of the pinion shafts are recombined beyond the bearing at a toothed ring. The recombined outputs are transmitted by way of a spiraltoothed coupling to the shell end. The division of the power between three pinion shafts serves to reduce the radial dimensions of the construction.However, because of the relatively small dimensions of the components of this construction, the toothed elements in it are heavily stressed. The decisive factor in the durability of such a drive is very uniform distribution of the load and the avoidance of load peaks leading to premature wear because of excessive flank pressure. If such a drive is to operate satisfactorily, precision in production and careful assembly and adjustment of the components are essential.

The beam end bearing is always a spherical shell bearing so that it is capabie of dealing with beam sagging and is always disposed approximately at the centre of the drive casing, beam loadings being transmitted by way of the bearing and drive casing to, for instance, an upright support element of the machine. In the known construction the bearing is disposed on a shoulder of the beam end and is secured axially thereon by a securing ring disposed in a peripheral groove. The ring is not accessible from outside the casing.

Consequently, to assemble this drive the transmission must be partly dismantled for fitting on the roll. This job is undertaken at the place where the roll is to be used-i.e., in a paper factory, which may well be an environment unsuitable for transmission assembly work. Careful assembly and accurate adjustment are therefore difficult. The time wasted, for example, when a drive is replaced at the place where the roll is used, and the associated downtime of other parts of the plant, are also a problem.

It is the object of the invention to devise a roll drive where the durability of the drive is improved and the time required for drive assembly is reduced.

According to this invention there is provided a roll comprising a rotating hollow shell as the operative periphery of the roll; a non-rotating beam extending through the shell over the whole length thereof, projecting from the shell ends and being borne by way of the parts thus projecting in a support member or column or the like by way of beam bearings permitting sagging of the beam, the beam being secured axially to one of the bearings; a drive for the shell acting on one end thereof and having a drive casing in which the corresponding beam bearing is disposed, said drive comprising a drive journal disposed outside one end of the beam and a number of pinion shafts distributed parallel to the beam axis, at positions spaced about the periphery of the end of the beam, said pinion shafts having pinions at both ends, one pinion of each shaft meshing with a central gear driven by the drive journal and the other pinion of each shaft meshing with a toothed element connected to corotate with with a ring flange which in turn is adapted to co-rotate with the shell, wherein means are provided for axially securing the drive to one end of the roll, said means allowing the complete drive to be located on and secured to or removed from the end of the roll as a whole.

Consequently, the drive can be fully assembled and adjusted at the manufacturer's works, the only work necessary at the place of use being to secure the drive to the roll shell and axially securing the drive-side bearing to the beam end. Thus the drive unit benefits from the better assembly conditions in the factory and the superior facilites available there for testing and adjustment. Also, the assembly time at the place of use is reduced since the only work to be done is to connect the ring flange to the shell and to attend to the axial securing.

Preferably said securing means can be brought into and taken out of operation from outside the drive casing. Advantageously said securing means comprise means which axially secure the beam end to a beam bearing. Conveniently said securing means are in the form of a transverse pin, said pin extending through part of a beam bearing and engaging in the beam end when operative and being introducable and withdrawable by way of a transverse passage in the drive casing.

Preferably said securing means comprise bolts which secure the ring flange to said shell.

Preferably at least one transport and assembly aid is provided in the form of an assembly stirrup, which bridges the means connecting the toothed element to the ring flange and provides a temporary rigid and aligned connection between the ring flange and the drive casing. This construction enables the drive parts to be held together during assembly and transport and to be seucred in a fixed position relative to one another.

Conveniently said toothed element and said central gear are retained radially solely by the tooth systems meshing with them. Advantageously said central gear has inner spur toothing engaged by similar outer spur toothing of said driving journal.

Power division and power combination may therefore become self-adjusting, thus ensuring optimum power division througout the line of drive.

Preferably said drive casing is a generally cylindrical casing having two cover plates which extend perpendicularly to the axis of the roll and receive the bearings of the pinion shafts.

This helps to ensure maximum precision of pinion shaft mounting and facilitates assembly of the drive casing. The cover plates can be drilled together, thus forming perfectly aligned apertures to receive the bearings. This is a process which is far simpler and more accurate than drilling a cast-iron casing with bores which are far apart from one another and which are in exact registration with one another.

Preferably the means connecting the toothed element to the ring flange comprises a cou pling sleeve which extends closely but noncontactingly around the beam end and is coni cal in the same sense as the beam end. This expedient may save radial space and is suit able for internal engagement with the toothed ring.

In some cases the shell end may be dis placed relative to the drive casing both radially and in flexion. Radial displacements are very likely to occur in cases in which the shell is not mounted on the beam and can move radi ally thereto. Even in cases in which the shell ends have bearings by way of which the shell bears on the beam, displacements are unavoidable since for constructional reasons the sealing arrangement cannot be made exactly the same height as the bearings, something which would have made accurate spacing between the shell and the main beam possible, and also because the sealing must be operative between the shell and the drive casing.

Also sagging of the beam end projecting from the shell make small displacements unavoidable.

To obviate these displacements a floating ring seal may be used. Thus, preferably a floating ring seal is provided between the shell end and the drive casing. In this arrangement the ring seal, instead of being disposed fixedly, is movable in its retaining arrangement and is entrained by the sealing surface in the displacements thereof while retaining sealing tightness.

Advantageously said floating ring seal has a retaining ring which extends around an axial, externally cylindrical extension of the shell and which is formed with at least one inner peripheral groove open towards said extension, a resilient ring seal being disposed in the or each groove and being biassed into engagement with said extension.

Preferably there are two of said grooves, each having a respective resilient ring seal, there being a loose ring disposed between said two grooves in a further inner peripheral groove in sealing relationship with said extension the further groove having a radial outlet at a position remote from said extension. This arrangement may improve sealing tightness in that any transferred pressure liquid is hurled radially outwards by the loose ring by way of a ring seal and discharged through the radial outlet before arriving at the next ring seal in any appreciable quantity.

Conveniently, the support means by which the shell bears internally on the beam are hydraulic support means, for example, a longitu dinal chamber filled with hydraulic fluid in the case of DE-PS 1 026 609 or a number of hydraulic pressure rams in DE-OS 2 230 139.

The hydraulic elements are not hermetically sealed in these disclosures; instead, a hydrodynamic state of equilibrium is reached in which there is always a small egress of hydraulic fluid which in the steady state must be continuously removed from the space between the shell and the beam. The hydraulic fluid has certain lubricating properties. Often, therefore, the hydraulic fluid issuing from the space between the shell and the beam goes directly to the drive casing and is used there to lubricate the transmission before being removed. Advantageously a seal is provided at the shell end between the shell and the beam and pre vents hydraulic fluid from flowing into the drive casing and a separate lubricant supply is provided for the drive casing.

Thus, the egress of hydraulic fluid from the space between the shell and the beam, when the support means by which the shell bears internally on the beam are hydraulic, can be inhibited (and the leakage fluid removed through the beam near the shell) and a separate supply of lubricant can be provided for the drive casing.

This has the advantage that the drive may be lubricated with an appropriate quantity of lubricant at an appropriate temperature, totally separately from the operation of the support means in the shell.

In order that the present invention may be more readily understood and so that further features thereof may be appreciated the invention will now be described by way of example with reference to the accompanying drawing which is a longitudinal section through the end of a roll according to the invention and through the drive casing associated therewith.

A roll 10 comprises a rotating shell 1 which serves as the operative periphery of the roll; a stationary beam 2 extends through the shell 1 along the length thereof and the shell 1 is supported in the beam 2 by way of internal support means which are operative on the shell inner periphery 3 and which are disposed on the beam 2. The support or bearing means can comprise a hydraulic pressure chamber, piston or plunger-like support or bearing elements or appropriate mechanical systems. The support means enable transverse forces applied to the shell 1 by the line or nip pressure to be transferred to the beam 2 which can sag within the shell 1 so that the bend line of the shell 1 itself is unaffected by the line or nip pressure loading. In the embodiment shown the shell 1 is mounted on bearings 60 disposed at the shell ends between the shell inner periphery 3 and the beam 2.

The beam ends project axially from the shell 1 in the manner shown in the drawing, which illustrates the power input end of the roller.

Disposed on the beam end 4 is a spherical shell bearing 5 having an inner element 6, which has a cylindrical inner peripheral surface, which engages the corresponding cylindrical outer peripheral surface of the beam end 4 so as to be axially displaceable along the beam.

An outer element 7 of the bearing 5 has a concave inner surface, which engages the outer part spherical surface of the element 6, and is mounted in the drive casing 8 of the drive 9 of roll 10.

The drive casing 8 comprises a generally cylindrical casing 11 which extends around the beam end 4 and which is bounded axially by two cover plates 12, 13 each extending perpendicularly to the beam axis. Transverse forces applied to the casing 11 via the bearing 5 are transmitted by the casing 11 to an upright support member (not shown) in which the casing 11 is supported. The upright support member forms part of the machine. The bearing 5 is located axially in a seat 14 in casing 11 by a collar 15 formed integrally with the seat on one side and by a locating ring 16 on the other side, which may be in the form of a circlip.An input journal 17 is mounted, with the interposition of two rolling bearings 18, 19, in the cover plate 13 shown on the right in the drawing and has, at its end extending into the casing 11, external spur toothing 20 meshing with substantially identical internal toothing 21 of a central gear 22.

The gear 22 is secured axially on journal 17 by securing rings 23 which bear on the end faces of the toothing 20. However, the central gear 22 is unmounted radially and provision is made for radial adjustment within a clearance allowed for this purpose.

Extending around the central gear 20 are three pinion shafts 24 which are distributed uniformly around the gear periphery and which are mounted by way of bearings 25, 26 in the opposite cover plates 12, 13 respectively. The shafts 24 have pinions at both ends; the righthand pinion 27 meshes with the central gear 22 as illustrated, and the pinion 28 on the left of the drawing, which is constituted by grooves cut in the pinion shaft 24, meshes with external toothing 29 of an axially extending but radially unmounted toothed ring 30 disposed radially within the three pinion shafts 24.Internal screw threading 31 of ring 30 cooperates with screw threading 32 of a coupling sleve 33 which extends through an aperture 34 in the plate 12 towards the shell 1, widens conically in this direction and extends around the beam end 4 at a small distance therefrom, the beam end 4 also widening conically in the same direction. At the end near the shell the sleeve 33 has further external screw threading 35 meshing with internal threading 36 of a ring flange 37 secured by bolts 38 to the end face of shell 1.Flange 37 has an axial projection 39 which extends towards the drive casing 8 and which has a cylindrical outer peripheral surface 40; disposed thereon is an arrangement 41 of sealing rings secured to the outside of the plate 12, which seals off the egress of hydraulic fluid between the drive casing 8 and the projection 39 in the direction indicated by arrow 61. The sealing arrangement 41 is in the form of a floating ring seal. The arrangement 41 comprises a retaining ring 52 which is secured on the end face of the plate 12 and engages over the extension 39 whose cylindrical outer peripheral surface is disposed opposite and in close proximity to the cylindrical inner peripheral surface of the retaining ring 52.In the embodiment, the inner peripheral surface of the ring 52 is formed with two axially spacedapart radial grooves 53 each receiving a radially mobile ring seal 54 in the form of a ring disc. Each ring seal 54 engages sealingly, by way of its radially extending edges, with the radial edges of the groove 53 and is restrained radially when the extension 39 moves axially relative to the ring 52. The rings 54 are made of a resilient low-friction and lowwear material, such as an appropriate plastics material and are preloaded to engage the cylindrical outside of the extension 39; the preloading may be reinforced by a peripheral tension spring.

Disposed between the two grooves 53 is another inner peripheral groove 55 in which a ring 56 is accommodated, the ring 56 engaging the extension 39 and being sealed therewith by an O-ring; the function of the ring 56 is to project hydraulic fluid which has penetrated below the right-hand ring seal 54 outwardly as the extension 39 rotates, so that such hydraulic fluid can be removed through a discharge 57 disposed on the bottom part of the groove 55. This removal of hydraulic fluid therefore prevents loading of the left-hand "final" ring seal 54.

The complete drive 9 is designed to be preassembied at the manufacturer's works, brought to the place of use as a unit and connected by means of the bolts 38 at the place of use to the roll 1, 2. To ensure that the sleeve 33 and the ring flange 37, which can of course move relative to the drive casing 8, do not move excessively and thereby endanger the ring seal arrangement 41, one or more assembly stirrups 42, shown in chaindotted lines in the drawing, are provided. The assembly stirrups 42 ensure that the sleeve 33 and ring flange 37 retain a substantially fixed position relative to the drive casing 8, thus facilitating assembly and transport of both the transmission and shell.The stirrups are U-shaped, their arms facing inwards and can be secured, by means of grooves which extend transversely through the arms, both to the cover plate 12 and to the ring flange 37.

For assembly, therefore, the complete drive 9 can be pushed on to the beam end 4 from right to left in the drawing, the inner element 6 of the bearing 5 sliding up on its seating surface 43 until the ring flange 37 abuts the end face of the shell 1. The bolts 38 may then be inserted and tightened.

To locate the beam 2 axially realtive to the drive casing 8, a transverse pin 50 is provided which is disposed outside the plane of the drawing and is therefore shown only in chain lines; the pin 50 extends through transverse bores 44, 45 in the beam end 4 and in the inner bearing element 6 respectively and thus locates the inner bearing element axially on the beam end 4 without impeding movement of the elements 6, 7 relative to one another. The drive casing 8 has a passage 46 through which the pin 50 is accessible from the outside for introduction and removal. the pin 50 is very short, and when in position does not extend beyond the outer part spherical surface of the inner bearing element 6. The only assembly work necessary at the place of use is to push the drive 9 on the beam end 4, tighten the bolts 38, introduce the transverse pin 50 and release the assembly stirrup 42.The drive elements proper are not touched during this assembly procedure and their adjustment, as set in the manufacturer's works, is not disturbed. The design is also preferable in other respects, for example, in that the transmission ratio can be varied simply by changing the central gear 22 and the pinion shafts 24. The casing 11 and all the other parts of the drive need not be altered.

The hydraulic support means operative between the shell inner periphery 3 and the beam 2 are a source of leakage fluid which must be removed continuously to-ensure steady conditions. In many cases the leakage fluid, which is a hydraulic fluid and has some lubricating properties, flows axially via the extension 39 (shown to the right) into the casing 8 where it lubricates the drive elements.

This liquid is removed continuously at an appropriate place. In another embodiment, however, the feature shown in chain lines in the drawing is used at the shell ends, wherein a lipped seal 58 disposed on the beam 2, engages a radial surface of the ring flange 37 and prevents the egress of hydraulic fluid from the space between the shell 1 and the beam 2. In this case the leakage fluid discharges through a special duct (not shown) in the beam 2. In this event the drive casing 8 has a separate lubricant supply line 59 through which a different lubricant, better suited to lubricate the drive elements and whose temperature and circulating quantity can be selected as required, can be supplied directly to the bearings.

Claims

1. A roll comprising a rotating hollow shell as the operative periphery of the roll; a nonrotating beam extending through the shell over the whole length thereof, projecting from the shell ends and being borne by way of the parts thus projecting in a support member or column or the like by way of beam bearings permitting sagging of the beam, the beam being secured axially to one of the bearings; a drive for the shell acting on one end thereof and having a drive casing in which the corresponding beam bearing is disposed, said drive comprising a drive journal disposed outside one end of the beam and a number of pinion shafts distributed parallel to the beam axis, at positions spaced about the periphery of the end of the beam, said pinion shafts having pinions at both ends, one pinion of each shaft meshing with a central gear driven by the drive journal and the other pinion of each shaft meshing with a toothed element connected to corotate with a ring flange which in turn is adapted to co-rotate with the shell, wherein means are provided for axially securing the drive to one end of the roll, said means allowing the complete drive to be lo cated on and secured to or removed from the end of the roll as a whole.

2. A roll according to claim 1, wherein said securing means can be brought into and taken out of operation from outside the drive casing.

3. A roll according to claim 1 or claim 2, wherein said securing means comprise means which axially secure the beam end to a beam bearing.

4. A roll according to claim 3, wherein said securing means are in the form of a transverse pin, said pin extending through part of a beam bearing and engaging in the beam end when operative and being introducable and withdrawable by way of a transverse passage in the drive casing.

5. A roll according to any one of the preceding claims wherein said securing means comprise bolts which secure the ring flange to said shell.

6. A roll according to any one of claims 1 to 5, wherein at least one transport and assembly aid is provided in the form of an assembly stirrup, which bridges the means connecting the toothed element to the ring flange and provides a temporary rigid and aligned connection between the ring flange and the drive casing.

7. A roll according to any one of claims 1 to 6, wherein said toothed element and said central gear are retained radially solely by the tooth systems meshing with them.

8. A roll according to any one of claims 1 to 7, wherein said central gear has inner spur toothing engaged by similar outer spur toothing of said driving journal.

9. A roll according to any one of claims 1 to 8, wherein said drive casing is a generally cylindrical casing having two cover plates which extend perpendicularly to the axis of the roll and receive the bearings of the pinion shafts.

10. A roll according to any one of claims 1 to 9, wherein the means connecting the toothed element to the ring flange comprises a coupling sleeve which extends closely but non-contactingly around the beam end and is conical in the same sense as the beam end.

11. A roll according to any one of claims 1 to 10, wherein a floating ring seal is provided between the shell end and the drive casing.

12. A roll according to claim 11, wherein said floating ring seal has a retaining ring which extends around an axial, externally cylindrical extension of the shell and which is formed with at least one inner peripheral groove open towards said extension, a resilient ring seal being disposed in the or each groove and being biassed into engagement with said extension.

13. A roll according to claim 11 or claim 12, wherein there are two of said grooves, each having a respective resilient ring seal, there being a loose ring disposed between said two grooves in a further inner peripheral groove in sealing relationship with said extension, the further groove having a radial outlet at a position remote from said extension.

14. A roll according to any of claims 1 to 13, wherein a seal is provided at the shell end between the shell and the beam and prevents hydraulic fluid from flowing into the drive casing and a separate lubricant supply is provided for the drive casing.

15. A roll substantially as herein described with reference to and as shown in the accompanying drawing.

16. Any novel feature or combination of features disclosed herein.