FIELD OF THE INVENTION
[0001] The invention relates to a suspension means for a traction sheave elevator, to a
traction sheave elevator comprising a suspension means, and to the use of the suspension
means.
TECHNICAL BACKGROUND
[0002] The use of belts instead of traditional ropes in elevators is an increasingly common
technology. Thanks to ropes with a much smaller diameter that are arranged horizontally
in the belt instead of the traditional large diameter ropes, a much smaller diameter
of the traction sheave is possible. In this way it is possible to achieve high torque
with much smaller motors.
[0003] One of the most common models of belts used in the industry is the flat belt. The
cross-sectional shape of this belt model is a simple rectangular polyurethane plastic
with rope cores or traction means strands inside.
[0004] Figure 1 shows a portion of a belt with a portion of a prior art traction sheave
or deflection pulley. Figure 2 shows the belt with a traction sheave or deflection
pulley of Figure 1 in cross-section from the front.
[0005] As can be seen in particular from Figure 2, conventional traction sheave or deflection
pulleys have a convex shape (crowned) for alignment. The convex surface creates a
force that keeps the belt centered as it rolls over the pulley or sheave. This is
the most common method for aligning flat belts. The closer you get to the edge of
the belt, the less contact there is between the belt and the pulley or sheave, with
the center of the belt making full contact with the pulley or sheave.
[0006] From the above configuration, a first technical problem arises.
[0007] The convex shape of the pulley or sheave solves the problem of aligning the belt
on the deflection pulley or traction sheave, but causes another technical problem.
Herein the deflection pulley or traction sheave are also referred to as pulley or
sheave. In general, the deflection pulley mounted on the motor shaft is referred to
as the traction sheave. To simplify matters, herein both the deflection pulley and
the traction sheave are often referred to as pulley or deflection pulley.
[0008] Due to the convex shape of the pulley, while the center of the belt is in full contact
with the pulley, the contact decreases toward the edge and a gap is created, which
can also be seen in Figure 2.
[0009] Therefore, when the belt rolls on the pulley, the central rope cores are subjected
to a high load, while the load on the rope cores at the sides of the belt is very
low in this design. That means, when the belt is flat and not on the pulley, the rope
cores share the load equally, but the central area is subjected to a much greater
load while on the pulley.
[0010] The main supporting elements of the belt are the rope cores, and the moment these
ropes rest on the pulley, they are deformed by bending and are subjected to the greatest
loads, which actually shortens the life cycle of the belt. In Figure 1, the load intensity
is shown by means of arrows.
[0011] From the above configuration, another technical problem arises.
[0012] Due to the flat geometry of the belt and the convex geometry of the pulley, the effective
contact area is limited to the center of the belt and pulley. This means that the
friction factor between the pulley and the belt, i.e. the tractive force of the motor,
is relatively low.
[0013] In the elevator industry, there are several profiled belt types in different shapes.
The most common form is multiple V-profiles on one side (i.e. on the flat side or
in the direction of width) of the belt, spread across the entire width of the belt.
[0014] So-called polyrope models, for example obtainable by ContiTech Hannover, have a flat
profile on one side and round profiles concentric with the rope cores on the other
side. So-called polyrope DP models, for example obtainable by ContiTech Hannover,
have round profiles concentric to the rope cores on one side and V-shaped profiles
on the other side.
[0015] Both, the multi-profile belts themselves and the pulley surfaces suitable for them,
are relatively difficult to manufacture because of the complex profile shape. In order
for them to function properly, they must be manufactured precisely and to tight tolerances.
In models with profiles on one side, the belt twists so that the profiled surfaces
of the belt come into contact with all the pulleys. As the belt rotates in this design,
it takes up more space in the horizontal arrangement.
[0016] On belt models with a profile on just one side, the flat side of the belt contacts
the pulleys when the belt is not running twisted. In this case, as with flat belts,
the pulley surface must have a convex radius to align the belt on the pulley. This
causes the first technical problem of the flat belt mentioned above, which occurs
with pulleys.
[0017] The model of the double-sided profiled belt, on the other hand, is the one with the
most difficult geometry and manufacturability. Complex pulley surfaces specific to
this belt profile must be manufactured, for both the motor side and deflection pulley
side. The cost of this belt is high due to its complex geometry and large volume of
polyurethane plastic. Using too much polyurethane will result in a higher unit weight
of the belt.
[0018] Round channels with a slightly larger diameter than the belt profile should be made
at the pulley, which are suitable for a belt with round profiles. Due to the different
diameters of the round profile of the belt and the round channels of the pulley, the
effective contact area between the pulley and the belt becomes relatively small. As
a result, the local tension in the polyurethane plastic is high and the friction ratio
between the pulley and the belt is relatively low.
TASK OF THE INVENTION
[0019] Accordingly, it is the task of the invention to provide a suspension means for a
traction sheave elevator which can be easily manufactured and in which the traction
force can also be increased.
SOLUTION ACCORDING TO THE INVENTION
[0020] A solution to this task is provided by claim 1.
[0021] The suspension means according to the invention for a traction sheave elevator in
the form of a flat belt with a plurality of traction means strands embedded in a friction-increasing
belt base material, via which they contact the traction sheave and possibly at least
one further deflection pulley during regular operation, has a width and a thickness
and is characterized in that the suspension means on a flat side has, in its central
area, at least one guide element protruding beyond the respective flat side in the
direction parallel to the belt thickness, preferably in the form of a rib (often also
called "ridge"), and in its lateral areas extending on both sides of the at least
one guide element is designed as a flat belt which does not carry any further guide
elements. Said "guide element" preferably is a form-fitting guide element.
PREFERRED EMBODIMENTS OF THE INVENTION
[0022] Further preferred embodiments are defined in the dependent claims.
[0023] In particular, the suspension means preferably has in its central area on both flat
sides at least one guide element protruding beyond the respective flat side in the
direction parallel to the belt thickness, preferably in the form of a rib, and in
its lateral areas extending on both sides of the at least one guide element (ideally
over at least two, preferably at least three, directly adjacent traction means strands)
is designed as a flat belt which carries no further guide elements. This guide element
is used, for example, to align the belt quickly and easily.
[0024] The rib is preferably convexly curved and preferably protrudes substantially or completely
in a part-circle manner in a direction parallel to the belt thickness.
[0025] According to the invention, the rib preferably protrudes in a V-shape in the direction
parallel to the belt thickness.
[0026] According to the invention, two guide elements protruding on different flat sides
preferably form a common center through which at least one, preferably exactly one,
tensile member runs.
[0027] According to the invention, the traction means strands are preferably ropes or metal
cables.
[0028] According to the invention, the use of a suspension means according to the invention
is such that it is preferably deflected in another direction, preferably by at least
170°, via at least one deflection pulley with a convexly curved suspension means contact
area.
[0029] A further preferred embodiment is a suspension means elevator with a suspension means,
with a deflection pulley designed as a traction sheave and preferably at least one
further deflection pulley, wherein at least one deflection pulley contacts the suspension
means with its cylindrical jacket, which has at least one counter guide element, preferably
in the form of a groove, which receives a guide element of the belt in such a way
that the belt is provided with the necessary lateral guidance which it requires in
order to run around the deflection pulley in the intended positioning. Said counter
guide element preferably is a mating or corresponding element to the aforementioned
guide element. Preferably, the guide element is at least partially in form-fitting
or positive-locking contact with the counter guide element.
[0030] According to the invention, the guide element of the suspension means is preferably
a convex rib and the mating guide element is a concave groove which is so much larger
than the rib that the rib, when symmetrically centered in the groove, contacts the
groove base in the area of its deepest point and there is no contact between the rib
and the groove in the two laterally adjoining flank areas.
[0031] Further according to the invention, the guide element of the suspension means is
preferably a V-shaped rib and the mating guide element is a V-shaped groove which
is dimensioned such that the V-shaped rib only rests against the V-shaped side walls
of the groove.
[0032] In accordance with the invention, the at least one deflection pulley preferably has
a belt running surface on its jacket which is wider than the width of the suspension
means in such a way that even if the deflection pulley has a laterally limiting board,
there is no lateral support of the suspension means on its flanks.
[0033] Further design possibilities, modes of operation and advantages can be seen in the
following description of the embodiment and/or on the basis of the figures.
FIGURE LIST
[0034]
Figure 1 shows a part of a belt with a part of a sheave or pulley according to the
prior art.
Figure 2 shows the belt with the sheave or pulley of Figure 1 in cross-section from
the front.
Figure 3 shows a first embodiment of the suspension means according to the invention
in cross-section.
Figure 4 shows the suspension means of the first embodiment with the pulley or sheave
in cross-section from the front.
Figure 5 shows a part of the suspension means of the first embodiment with a part
of a pulley or sheave.
Figure 6 shows a second embodiment of the suspension means according to the invention
in cross-section.
Figure 7 shows the suspension means of the second embodiment with the pulley or sheave
in cross-section from the front.
Figure 8 shows the structure of a traction means strand.
PREFERRED DESIGN OPTIONS
[0035] Figures 3 to 5 show a first embodiment of the suspension means according to the invention.
[0036] Figure 3 shows a cross-section of the suspension means 1 according to the invention.
The suspension means 1 is designed for a traction sheave elevator. Preferably, the
traction sheave elevator is a vertical elevator in which a car moves (in particular
vertically) along an actual elevator shaft or an elevator shaft defined by at least
a frame-like enclosure.
[0037] The traction sheave elevator or vertical elevator is suspended from one or more of
the suspension means 1 according to the invention. The suspension means 1 has a width
B and a thickness D and is preferably a flat belt 4. The suspension means 1 or the
flat belt 4 may comprise one traction means strand 3 or several traction means strands
3. The one traction means strand 3 or the plurality of traction means strands 3 comprise
ropes or metal cables.
[0038] The flat belt 4 consists of a friction-enhancing belt base material and advantageously
consists at least predominantly of non-metallic material, and/or of a uniform material
or of a material which differs in layers or areas. Advantageously, the belt base material
of the suspension means 1 or of the belt 4 consists of rubber, plastic or a plastic
mixture or a composite material, but preferably of polyurethane plastic. Of course,
a mixed form of metallic and all or part of the aforementioned materials can also
be used for the basic belt material of the suspension means 1 or of the belt 4, although
a mixed form of all or part of the aforementioned materials is preferred for the basic
belt material without a metallic component.
[0039] Further preferably, the belt base material transmits substantially no tensile forces
past the traction means strands 3 in the direction along their longitudinal axis,
in which belt base material they are embedded and via which they contact the pulley
6 or sheave 6 and possibly a further pulley 6 in regular operation.
[0040] In its central area 10, the suspension means 1 has at least one guide element 5 protruding
on a flat side over the respective flat side in the direction parallel to the belt
thickness D. Preferably, only a single, ideally precisely centered guide element 5
is arranged on one flat side. Further preferably, only a single, ideally exactly centered
guide element 5 is arranged on each flat side.
[0041] The guide element 5 is preferably in the form of a rib 2. Further preferably, in
each case one rib 2 and in particular only one rib 2 is arranged or formed on in each
case one flat side of the suspension means 1 or of the belt 4, as is shown in Figures
3 to 5.
[0042] In Figures 3 and 4, it can be seen clearly that the lateral areas 11 of the suspension
means 1 extend in the width direction from the outer sides or flanks 9 preferably
to the guide element 5. In other words, a lateral area 11 preferably lies between
the guide element 5 and the flank 9 or the side of the suspension means 1 that is
perpendicular to the width direction, i.e. in the thickness direction. As mentioned
above, the suspension means 1 has a width B in the width direction and a thickness
D in the thickness direction, the width direction being perpendicular to the thickness
direction.
[0043] The longitudinal direction of the belt 4 is perpendicular to the direction of the
width and perpendicular to the direction of the thickness, wherein the length of the
belt 4 is longer than the width of the belt 4, and the width of the belt 4 is longer
than the thickness of the belt 4. The length of the belt 4 corresponds to the distance
along the longitudinal direction. The width of the belt 4 corresponds to the distance
along the direction of the width or width direction. The thickness of the belt 4 corresponds
to the distance along the direction of the thickness or thickness direction.
[0044] The flat side of the suspension means 1 or belt 4 lies in the width direction as
seen in cross-section. The flat side has a central area 10 located at the centerline
M or central axis M and further has a lateral area 11 on each outer side or flank
9 of the suspension means 1. The flat side is bisected by the central axis M, the
central axis M being parallel to the thickness direction and thus perpendicular to
the width direction. The two flat sides or the upper side and lower side of the belt
4 are preferably parallel to each other, with the flank 9 or the outer side of the
belt 4, which is the lateral boundary of the belt 4, running perpendicular to the
upper and lower sides. Thus, apart from the guide elements 5, the flat belt 4 has
a substantially square cross-section, as shown in Figure 3. Preferably, the guide
element 5 is arranged centrally in the width direction. Further preferably, the suspension
means 1 or the belt 4 has lateral areas 11 which preferably extend in each case over
at least two, preferably at least three, directly adjacent traction means strands
3. Preferably, the flat lateral areas 11 of the flat belt 4 have or carry essentially
no further guide elements 5.
[0045] Advantageously, the thickness-to-width ratio is substantially in the range of 1:5
to 1:25, preferably 1:10 to 1:20, more preferably 1:12 to 1:18, although the ratio
is determined by the particular requirements, such as those relating to maximum load
or space conditions.
[0046] It can further be seen in Figures 3 to 5 that the suspension means 1 has in its central
area 10 on both flat sides in each case at least one guide element 5 protruding beyond
the respective flat side in the direction parallel to the belt thickness D, preferably
in the form of a rib 2, and in its lateral areas 11 extending on both sides of the
at least one guide element 5, preferably over at least two, preferably at least three
directly adjacent traction means strands, is designed as a flat belt 4 which has or
carries no further guide elements 5.
[0047] Further preferred, the rib 2 or the guide element 5 protrudes in a V-shape in the
direction parallel to the belt thickness D.
[0048] The guide elements 5 rising on different flat sides (i.e. upper and lower sides)
preferably form a common center through which at least one traction means strand 3,
preferably exactly one traction means strand 3, runs. The traction means strands 3
are at least partially, preferably predominantly and ideally completely ropes, preferably
metal ropes.
[0049] Since the lateral load on the suspension means 1 or flat belt 4 is very low, not
many profiles or guide elements 5 are needed to keep the suspension means 1 or belt
4 in line. The best friction factor between the pulley 6 and the suspension means
1 or flat belt 4 is achieved when both the suspension means 1 or flat belt 4 and the
pulley 6 are flat.
[0050] Thus, the suspension means 1 or flat belt 4 of the embodiment according to the invention
combines the advantages of flat belts and multi-profile belts and eliminates their
disadvantages.
[0051] In the center of the rectangular belt 4 there is a single guide element 5 or rib
2, which is symmetrically arranged on both the upper and lower sides and keeps the
belt in line with the pulley or traction sheave 6. This guide element 5 or rib 2 on
both sides ensures that the shape of the pulley 6 is the same on both the motor side
and deflection pulley sides and is aligned in the same way on both sides.
[0052] Due to this design, the effective contact area between belt 4 and pulley 6 is much
larger. In this way, the tensile force of the engine belt is increased.
[0053] In Figure 4 it can be seen that all surfaces of the pulley 6, with the exception
of the belt groove or the counter guide element 7, are flat or planar (i.e. have no
convex shape). As a result, the belt cores or traction means strands 3 are always
subjected to the same load and stress. The belt cores or traction means strands 3
distribute the load evenly in each position, as can be seen in Figure 5, where the
load intensity is shown by means of arrows.
[0054] Figures 6 and 7 show a second embodiment of the suspension means according to the
invention.
[0055] Figure 6 shows a cross-section of the suspension means 1 according to the invention.
As can be easily seen, the first embodiment differs from the second embodiment only
in the shape of the form-fitting guide element 5. In the first embodiment, the form-fitting
guide element 5 is preferably V-shaped. As it can be easily seen in Figures 6 and
7, in the second embodiment of the suspension means according to the invention, the
guide element 5 has a round or circular or oval shape. All other features and advantages
correspond to the first embodiment and also apply to the second embodiment, and are
hereby incorporated by reference thereto.
[0056] In the second embodiment shown in Figures 6 and 7, the rib 2 is, preferably substantially
continuously convexly curved and preferably substantially or completely part-circularly
protruding in the direction parallel to the belt thickness D.
[0057] Also due to this design, the effective contact area between belt 4 and pulley 6 is
much larger. In this way, the tensile force of the engine belt is also increased.
[0058] In Figure 7 it can be seen that all surfaces of the pulley 6, with the exception
of the belt groove or the counter guide element 7, are flat or planar (i.e. have no
convex shape). As a result, the belt cores or traction means strands 3 are always
subjected to the same load and stress. Here, too, the belt cores or traction means
strands 3 distribute the load evenly in each position.
[0059] Preferably, a suspension means 1 according to one of the above embodiments is used
in such a way that it is deflected in another direction, preferably by at least 170°,
via at least one deflection pulley 6 with a convexly curved suspension means contact
area. In this case, however, the "convexly curved contact area" means only the curvature
due to the preferably round shape of the deflection pulley 6 and therefore the curvature
of the deflection pulley 6 along the longitudinal axis L of the belt . This "convexly
curved contact area" does not mean the convex (or crowned) shape of the deflection
pulley 6 in the plane defined by the belt thickness D and the belt width B, which
is shown as state of art in Fig. 1. The convex (or crowned) shape shown in Fig. 1
is no longer present in a deflection pulley 6 according to the invention.
[0060] According to the invention, a suspension elevator has a suspension means 1 according
to one of the above embodiments. The car of the suspension means elevator is suspended
on the suspension means 1 and is raised or lowered accordingly, namely by means of
a deflection pulley 6 designed as a traction sheave and preferably at least one further
deflection pulley 6. The at least one deflection pulley 6 contacts the suspension
means 1 with its cylindrical jacket, which has at least one counter guide element
7, preferably in the form of a groove 8, which receives a guide element 5 of the suspension
means 1 or belt 4 in such a way that the belt 4 is guided by the counter guide element
7, which receives a guide element 5 of the suspension means 1 or belt 4 in such a
way that the belt 4 is provided with the necessary lateral guidance which it requires
in order to run over the deflection pulley 6 in the intended positioning.
[0061] Particularly preferably, the cylindrical jacket of the deflection pulley 6 contacting
the suspension means 1 is planar or straight or flat, and in particular in the width
direction.
[0062] Preferably, the guide element 5 of the suspension means 1 is a convex rib 2 and the
counter guide element 7 is a concave groove 8, which is larger than the rib 2 by so
much that the rib 2, when symmetrically centered in the groove 8, contacts the groove
base in the area of its deepest point and there is no contact between the rib 2 and
the groove 8 in the two laterally adjoining flank areas.
[0063] Further preferably, the guide element 5 of the suspension means 1 is a V-shaped rib
2 and the counter guide element 7 is a V-shaped groove 8, which is or are dimensioned
such that the V-shaped rib 2 rests only against the V-shaped side walls of the groove
8.
[0064] Particularly preferably, the counter guide element 7 is arranged centrally on the
jacket of the deflection pulley 6, and in particular in the width direction.
[0065] In the suspension means elevator according to the invention, the at least one deflection
pulley 6 has on its jacket a belt running surface which is wider than the suspension
means width, in such a way that even if the deflection pulley 6 has laterally limiting
boards 6a, there is no lateral support of the suspension means 1 on its flanks 9.
[0066] In this application, a board 6a is understood to be a lateral boundary of the deflection
pulley 6 or traction sheave 6, as shown for example in Figures 4 and 7. The flank
9 of the belt 4 faces the respective board 6a.
[0067] The suspension means elevator has a suspension means line on which the car of the
suspension means elevator is suspended and on which it can be raised or lowered accordingly.
The suspension means line comprises one or more suspension means 1. Preferably, the
flanks 9 of the individual suspension means 1 in the suspension means line are parallel
to each other. Further preferably, the suspension means line comprises four suspension
means 1 or belts 4 which run parallel. Further preferably, the flank 9 of a suspension
means 1 runs at or near the flank 9 of another suspension means 1.
[0068] In the figures, the rope cores or traction means strands 3 are shown simply round.
However, any other shape such as, for example, oval, rectangular or a polygonal shape
may be possible since the traction means strands 3 are made by braiding together wires
(metallic and/or non-metallic wires) of much smaller diameter. Thus, the shape and/or
the materials may vary.
[0069] The structure of an individual traction means strand 2 can be understood from Fig.
8. This shows that the individual traction means strands 3 are not made of solid material
but are formed by a large number of thin steel wires which are interwoven with one
another.
REFERENCE LIST
[0070]
- 1
- Suspension means
- 2
- Rib
- 3
- Traction means strand or belt core
- 4
- Flat belt or belt
- 5
- Guide element
- 6
- Traction sheave or deflection pulley or pulley
- 6a
- Board
- 7
- Counter guide element
- 8
- Groove
- 9
- Flank
- 10
- Central area
- 11
- Lateral area
- B
- Belt width or width
- D
- Belt thickness or thickness
- M
- Center line or central axis or midline
1. Suspension means (1) having a width (B) and a thickness (D) for a traction sheave
elevator in the form of a flat belt (4) with a plurality of traction means strands
(3) which are embedded in a friction-increasing belt base material via which they
contact the traction sheave (6) and optionally at least one further deflection pulley
(6) during regular operation, characterized in that the suspension means (1) on a flat side has, in its central area (10), at least one
guide element (5) protruding beyond the respective flat side in the direction parallel
to the belt thickness (D), preferably in the form of a rib (2), and in its lateral
areas (11) extending on both sides of the at least one guide element (5) is designed
as a flat belt (4) which does not carry any further guide elements (5) .
2. Suspension means (1) for a traction sheave elevator according to claim 1, characterized in that the suspension means (1) has in its central area (10) on both flat sides in each
case at least one guide element (5) protruding beyond the respective flat side in
the direction parallel to the belt thickness (D), preferably in the form of a rib
(2), and in its lateral areas (11) extending on both sides of the at least one guide
element (5) is designed as a flat belt (4) which carries no further guide elements
(5).
3. Suspension means (1) for a traction sheave elevator according to one of the preceding
claims, characterized in that the rib (2) is convexly curved and preferably protrudes in a part-circular manner
in the direction parallel to the belt thickness (D).
4. Suspension means (1) for a traction sheave elevator according to one of the preceding
claims with the exception of the immediately preceding claim, characterized in that the rib (2) protrudes in a V-shape in the direction parallel to the belt thickness
(D).
5. Suspension means (1) according to one of the preceding claims, characterized in that two guide elements (5) raised on different flat sides form a common center through
which at least one traction means strand (3) runs.
6. Suspension means (1) according to one of the preceding claims, characterized in that the traction means strands (3) are ropes, preferably metal ropes.
7. Use of a suspension means (1) according to one of the preceding claims in such a way
that it is deflected in another direction, preferably by at least 170°, via at least
one deflection pulley (6) with a convexly curved suspension means contact area.
8. Suspension means elevator with a suspension means (1) according to one of the preceding
claims with a deflection pulley (6) designed as a traction sheave and preferably at
least one further deflection pulley (6), characterized in that at least one deflection pulley (6) contacts the suspension means (1) with its cylindrical
jacket, which has at least one counter guide element (7), preferably in the form of
a groove (8), which receives a guide element (5) of the belt (4) in such a way that
the belt (4) is provided with the necessary lateral guidance which it requires in
order to be run over the deflection pulley (6) in the intended positioning.
9. Suspension means elevator according to the immediately preceding claim, characterized in that the guide element (5) of the suspension means (1) is a convex rib (2) and the counter
guide element (7) is a concave groove (8) which is so much larger than the rib (2)
that the rib (2), when symmetrically centered in the groove (8), contacts the groove
base in the area of its deepest point and in the two laterally adjoining flank areas
there is no contact between the rib (2) and the groove (8).
10. Suspension means elevator according to claim 8, characterized in that the guide element (5) of the suspension means (1) is a V-shaped rib (2) and the counter
guide element (7) is a V-shaped groove (8) which is dimensioned such that the V-shaped
rib (2) rests only against the V-shaped side walls of the groove (8).
11. Suspension means elevator according to one of the three immediately preceding claims,
characterized in that the at least one deflection pulley (6) has on its jacket a belt running surface which
is wider than the suspension means width (B), in such a way that no lateral support
of the suspension means (1) takes place on its flanks (9) even if the deflection pulley
(6) has laterally limiting boards (6a) .