||Walze sowie Distanzring dafür
||Sandvik Intellectual Property AB, Sandviken, SE
||Kayhan, Menderez, 147 50 Tumba, SE;
Ankaragren, Jimmy, 120 58 Arsta, SE
||derzeit kein Vertreter bestellt
||AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HU, IE, IS, IT, LI, LT, LU, LV, MC, NL, PL, PT, RO, SE, SI, SK, TR
|Sprache des Dokument
|Veröffentlichungstag im Patentblatt
B21B 27/03(2006.01)A, F, I, 20061121, B, H, EP
Technical Field of the Invention
This invention relates to a roll that comprises a roll
shaft having a rotationally symmetrical basic shape that is defined by a central
axis, as well as a number of rings mounted on the roll shaft, each one of which
has two planar end surfaces extending between outer and inner, circular limiting
edges, and serving as friction contact surfaces for the transmission of torque to
adjacent rings. Such rolls are usually referred to as combi rolls.
Frequently, the rolls include two or more roll rings, which
are kept separated by intermediate spacer rings, the entire set of rings being kept
fixed on the shaft by way of, on one hand, a fixed stop ring, e.g., a shoulder of
the roll shaft, and, on the other hand, a lock nut that via an internal thread may
be tightened on a male thread of the shaft. Furthermore, between the lock nut and
the set of roll rings, spring devices as well as additional spacer rings may be
In many cases, the roll rings are manufactured from cemented
carbide, while the intermediate spacer rings are manufactured from a softer or more
ductile material, preferably steel or cast iron. Considerable torque should be transmitted
to the roll rings from the roll shaft. When the roll rings are made of solely cemented
carbide, this usually takes place by an axial (cylindrical) train of forces from
the lock nut to the fixed stop ring via the contact surfaces between the individual
rings. More precisely, the torque is transmitted from the individual ring to an
adjacent ring by a friction action in the interfaces, where an end surface of a
ring is pressed against a co-operating end surface of the adjacent ring. In order
to fulfil this task throughout the train of forces, the individual friction joints
between the rings have to be powerful, i.e., be able to transfer torque without
the rings slipping in relation to each other.
In previously known combi rolls (see, for instance,
) the roll rings as well as the spacer rings are formed with end surfaces
extending radially all the way from the inside to the outside, i.e., from the envelope
surface of the roll shaft to the external cylinder surface of the individual ring.
However, this fact has turned out to be detrimental for the ability of the friction
joints to transmit a large torque between the rings. Thus, the described design
results in the transmission of force in a zone situated about halfway between the
inside and the outside of the spacer ring, i.e., as close to the envelope surface
and the centre axis of the roll shaft, respectively, as possible. Furthermore, the
surface pressure in the interfaces between the contact surfaces becomes relatively
low because the contact surfaces are comparatively large. For these reasons, it
may happen that the rings slip in relation to each other, something which in turn
may lead to production interruptions and in the worst case roll breakdowns.
Objects and Features of the Invention
The present invention aims at obviating the above-mentioned
shortcomings of previously known combi rolls and at providing an improved roll.
Therefore, a primary object of the invention is to provide a combi roll in which
large torques may be transferred between adjacent rings via friction joints, which
in a reliable way counteract slipping between the rings. In other words, the invention
aims at providing powerful and efficient friction joints between the rings in the
roll. It is also an object to provide the improved friction joints by simple elements
and in a manner that even can be material-saving.
According to the invention, at least the primary object
is attained by way of the features, which are defined in the characterizing clause
of the independent claim 1. Preferred embodiments of the roll according to the invention
are further defined in the dependent claims 2-6.
In another aspect, the invention also relates to a ring
as such, in particular a spacer ring. The features of this ring are found in the
independent claim 7.
Brief Description of the Appended Drawing
In the drawing:
Detailed Description of Preferred Embodiments of the Invention
- Fig. 1 is a partly cut longitudinal view through a combi roll according to the
- Fig. 2 is an enlarged cross section of a spacer ring included in the roll of
- Fig. 3 is a perspective view of the spacer ring, and
- Fig. 4 is a cross section schematically illustrating an alternative embodiment
of the invention.
In Fig. 1 a roll is shown, which includes a drivable roll
shaft 1, three roll rings 2, and three spacer rings 3. The roll shaft 1 has a rotationally
symmetrical basic shape that is defined by a central axis C.
The set of rings 2, 3 is kept in place between a fixed
stop ring 4, which in the example is in the form of a ring-shaped shoulder, and
a lock nut 5 at the opposite end of the shaft. The lock nut has an internal thread
(not visible), which may be tightened on an external thread of the roll shaft. Between
the lock nut 5 and the first roll ring 2, there is, in this case, also a dynamic
spring 6, which is separated from the lock nut 5 via a tightening ring 7. Furthermore,
in the lock nut, there is a number of peripherally spaced-apart adjusting devices
8 by way of which the spring force in the spring 6 can be adjusted.
In the example, the roll rings 2 are assumed to be composed
of solid cemented carbide, while the spacer rings 3 are made from a more ductile
or softer metal, e.g., steel. Each individual roll ring 2 is delimited by external
and internal cylinder surfaces 9, 10 as well as opposite end surfaces 12, each one
of which is planar and extends perpendicularly to the centre axis C. Each end surface
12 is limited outwardly by a circular limiting edge line 13 and inwardly by an inner,
likewise circular edge line 14.
In an analogous way, the individual spacer ring 3 (see
Fig. 3) is delimited by an external cylinder surface 11, which defines the outer
diameter of the spacer ring, an internal cylinder surface 10, which defines the
inner diameter of the spacer ring, as well as two opposite planar end surfaces 15,
which extend perpendicularly to the centre axis C.
As far as the shown roll has been described hitherto, the
same is in all essentials previously known, however with the exception of the design
of the spacer rings 3. In previously known spacer rings, the planar end surfaces
15 have extended radially all the way from the internal cylinder surface 10 to the
external cylinder surface 11. In other words, the spacer rings have had the same
general design as the tightening ring 7 shown to the right in Fig. 1.
According to an aspect of the present invention the individual
end surface 15 of the spacer ring 3 has been shaped in such a way that the inner
limiting edge line 17 of the surface is greater than the outer diameter of the roll
shaft, which in the example according to Fig. 4 corresponds to the inner diameter
of the ring. (Outwardly the end surface 15 is limited by the circular edge line
16). In such a way, the total area of the end surface 15 for a given outer diameter
is reduced, whereby the surface pressure against an adjacent roll ring is increased.
Furthermore, the force tramsmission zone (i.e., an imaginary circular line halfway
between the limiting edge lines 16 and 17) of the surface is moved out in comparison
the corresponding force transmission zones in previously known spacer rings. In
other words, the efficient torque arm is increased, such as this is determined by
the radial distance between the centre axis C and the force transmission zone.
In the example shown in Figs. 1, 2 and 3, the desired reduction
of the area of the end contact surface 15 has been provided by the fact that the
ring has been formed with, on one hand, an outer rim part 18, which has a thickness
- measured as the distance between the opposite end surfaces 15 -that is greater
than the thickness of an inner rim part 19, in which the hole of the ring delimited
by the cylinder surface 10 is formed. By way of the inner rim part 19, the ability
of the spacer ring to be centred is retained, when it is put on to the roll shaft
1. As is seen in Fig. 3, the outer rim part 18 has a radial extension (the radial
distance R1 between the limiting edge lines 16, 17) which is smaller than the radial
extension of the inner rim part 18, such as this is represented by the radial distance
R2 between the limiting line 17 and the hole edge surface 10. In practice, R1 may
amount to 50-80 %, suitably 60-70 % of R2, i.e. R2 may be 25 to 100%, or 42 to 66%
greater than R1.
In Fig. 4, an alternative embodiment of a roll is shown
in which the spacer ring 3A lacks the centering inner rim part according to the
embodiment described above. Thus, in this case, a rotationally symmetrical hole
edge surface 10A extends axially between the opposite inner edgelines 17 of the
end surfaces 15. Centering of this spacer ring may either be effected by way of
externally applied centering devices, or by way of an inner, ring-shaped core of
another material, e.g., cellular plastic, wood or the like, which may be destroyed
A layer of a large number of uniformly distributed grains
may be applied to the interfaces between the end surfaces of the roll rings 2 and
of the spacer rings 3, which grains are made from a material that is harder than
the hardest material in anyone of the rings. If the roll rings are manufactured
of cemented carbide, grains of, for instance, diamond, cubic boron nitride, ceramics
or the like, may be used. The grains should have a size that is at least somewhat
greater than the microscopic irregularities that decides the surface finish of the
contact surfaces. When the roll rings and the spacer rings are urged towards each
other by full force, the grains will then penetrate into the respective end surface
and to a large extent increase the friction between the surfaces. Such grains do
not make the separation of the rings from each other materially more difficult.
In practice, the grains may be included in a paste or another viscous fluid, which
may be provided onto the comparatively narrow, ring-shaped end contact surfaces
of the spacer rings. Alternatively, the grains may be applied by plating technique.
Feasible Modifications of the Invention
The invention is not limited merely to the embodiments
described above and shown in the drawings. Thus, it is feasible to form the radially
reduced end contact surface on a roll ring, instead of on a spacer ring, although
the exemplified embodiment is preferred in practice.
Roll comprising a roll shaft (1) having a rotationally symmetrical basic
shape that is defined by a centre axis (C), as well as a number of rings (2, 3)
mounted on the roll shaft (1), each one of which has two planar end surfaces (12,
15) extending between outer and inner, circular limiting edges (13, 14 and 16, 17,
respectively), and serving as friction contact surfaces for the transmission of
torque to adjacent rings, characterized in that at least one of the end surfaces
(15) of a ring is limited by an inner edge (17), the diameter of which is greater
than the outer diameter of the roll shaft (1) .
Roll according to claim 1, characterized in that the end surface
(15) is included in a spacer ring (3) and is urged against an end surface of a roll
Roll according to claim 1 or 2, characterized in that the two
opposite end surfaces (15) of the ring are both limited by inner edges (17), the
diameters of which are greater than the outer diameter of the roll shaft (1).
Roll according to claim 2 or 3, characterized in that the spacer
ring (3) includes an outer rim part (18) having an axial thickness - measured as
the distance between the opposite end surfaces (15) - that is greater than the thickness
of an inner rim part (19), which has an internal, rotationally symmetrical hole
edge surface (10), the diameter of which corresponds to the diameter of the roll
Roll according to claim 4, characterized in that the radial distance
(R1) between the outer and inner limiting edges (16, 17) of the individual end surface
(15) is smaller than the radial distance (R2) between the inner limiting edge (17)
and the hole edge surface (10).
Roll according to any one of claims 1-3, characterized in that
axially between the inner limiting edgelines (17) of the two end surfaces (15),
a rotationally symmetrical surface extends, which forms an internal hole edge surface
(10A) and has a diameter equal to the diameter of the limiting edgelines (17).
A spacer ring for rolls, having external and internal, rotationally
symmetrical limiting surfaces (11, 10), as well as two planar end surfaces (15)
axially spaced-apart and facing away from each other, that extend between outer
and inner, circular limiting edgelines (16, 17), and serve as force transmitting
friction contact surfaces against other rings included in a roll, characterized
in that the individual, force transmitting end surface (15) is limited by an
inner edgeline (17), the diameter of which is greater than the inner diameter of
the ring, such as this is determined by the internal limiting surface (10).
Patent Zeichnungen (PDF)