WO2019238318A1

WO2019238318A1 - Link chain

Info

Publication number: WO2019238318A1
Application number: PCT/EP2019/061846
Authority: WO
Inventors: Stefan Kemper; Kai Silberg
Original assignee: Ketten-Wulf Betriebs-Gmbh
Priority date: 2018-06-11
Filing date: 2019-05-08
Publication date: 2019-12-19
Also published as: DE102018113882A1

Abstract

The invention relates to a link chain comprising: a plurality of outer plates (4) which oppose each other in pairs in the transverse direction of the chain; a plurality of inner plates (3) which oppose each other in pairs in the transverse direction of the chain; a plurality of link pins (2) which are each connected for conjoint rotation to two outer plates (4) which oppose each other in the transverse direction of the chain; a plurality of link bushes (1) which are each connected for conjoint rotation to two inner plates (3) which oppose each other in the transverse direction of the chain, the link bushes (1) each surrounding a link pin (2) at least in sections; and a plurality of sliding bearings (5) which are each arranged between a link pin (2) and a link bush (1), each of the sliding bearings (5) having a supporting layer (6) and a sliding layer (7) which each comprise a plastic-based matrix material.

Description

"Link chain"

The present invention relates to an articulated chain according to the

Preamble of claim 1 or according to the preamble of

Claim 15. Furthermore, the present invention relates to a

Use of such link chains.

Link chains made of steel are used in conveyor technology when high tensile forces have to be transmitted. From these high

Tensile forces result in corresponding stresses

for example in the form of surface pressures between the

Hinge pin and the hinge bush. This surface pressure is, in combination with other influences such as abrasive foreign substances, for a progressive wear of the

Chain link causative. The chain joints wear as a result of the surface pressure, whereas other influences such as abrasive media accelerate the process.

The prior art essentially describes two ways in which the progress of wear in the chain links can be reduced in order to achieve an acceptable service life. On the one hand this is the continuous respectively

discontinuous lubrication of the chain links with oil or grease during operation and secondly the use of plain bearings.

Bush conveyor chains that operate with oil

or grease are lubricated and their joint does not include a plain bearing, are designed with a joint surface pressure of up to 50MPa. Chains with a plain bearing between the pin and the joint bushing are the same

Joint dimensions with a lower surface pressure

designed. This has the consequence that the joint dimensions at Chains with plain bearings, compared to chains without plain bearings, are much larger with the same pulling force. This in turn has the consequence that the link plates must also be dimensioned larger due to the larger division holes due to the larger joint dimensions. As a result, the chain weight and the space required increase. The additional installation space required can be problematic in the case of complex and housed systems, such as an escalator.

6 shows a section through a chain link of a link chain according to the prior art, which is oil-lubricated

Bush conveyor chain is formed. The cut shows one

Hinged bushing 11, a hinge pin 12 and two inner and outer plates 13, 14 each. With this type of construction, the chain joint, in particular the hinge pin 12 and the hinge bushing 11, are provided with initial lubrication from grease or oil during assembly. Furthermore, chains of this type must be in operation

be continuously supplied with oil as a lubricant to

Slow down chain link wear. As a rule, the oil is dripped continuously on both sides between the inner and outer plates 13, 14 with the aid of a so-called drip oiler (see arrows 15 in FIG. 6).

The disadvantage here is the release of the lubricant from the

Initial lubrication to the environment, the cost of purchasing a suitable lubrication device such as one

Drip oiler, the costs for the procurement and storage of the lubricant, the costs for the disposal of the oil residues or the waste oil as well as the contamination of the systems and / or the environment and / or the conveyed goods

Oil residues. 7 shows a joint section through a bushing chain lubricated with grease according to the prior art. The section shows a hinge pin 12 with a lubrication bore 16, one

Articulated bushing 11, two seals 17 between each other

opposite inner and outer plates 13, 14, four covers 18 and a grease nipple 19. During assembly, both the chain link and the seals 17 are provided with initial lubrication from grease or oil in this type of construction. As a rule, chains of this type are relubricated during operation. That means that after a certain interval new

Grease is pressed manually or automatically, for example through the grease nipple 19 into the chain link. Old one

Lubricating grease can escape to the outside through the construction of the seals 17 when the new lubricating grease is under pressure.

The disadvantage here is the release of the lubricant from the

Initial lubrication to the environment, the cost of purchasing and storing the lubricants, the cost of the

Purchase of an automatic lubrication system

or the costs for manual relubrication, the contamination of the systems and / or the environment and / or the material to be conveyed due to lubricant residues, the reduction in the breaking force of the pivot pin due to the introduced

Lubrication holes and an elaborate seal construction that must be consistent for lubricant. Additional components or special preparation or mechanical processing of the sealing surfaces may also be required.

Fig. 8 shows the joint section of a bush conveyor chain

Plain bearings 20. The section shows a hinge pin 12, a

Slide bearing 20, a joint bushing 11, two seals 17 and four covers 18. For chain links that have at least one slide bearing 20 comprise, which is positioned between the hinge pin 12 and the hinge bush 11, an initial lubrication may also have to be provided according to the prior art. Both the slide bearing 20 and the seals 17 are initially lubricated with grease during assembly. There is no other one operating the chain

Lubrication necessary.

Disadvantages here are the initial lubrication of the slide bearings to reduce the wear of the chain link, the initial lubrication of the seals to reduce the wear of the seals, the release of the lubricant from the initial lubrication of the slide bearings to the environment and / or the system and / or that Conveyed goods, the

Delivery of the lubricant from the initial lubrication of the seals to the environment and / or the system and / or the material to be conveyed, as well as an elaborate seal construction. Another disadvantage is the reduction of the maximum permissible joint surface pressure. The load capacity is particularly limited because the material of the

Plain bearing must be processed thermoplastically. Due to the flomogeneity of the plain bearings, plain bearings of this type cannot be adapted locally to the loads. Furthermore are under

Additional components or additional machining of the sealing surfaces may be necessary to optimize the sealing system.

An articulated chain of the type mentioned at the outset is known from EP 0775 079 B1, which likewise discloses a bushing conveyor chain with a plain bearing. The plain bearing described in it is a homogeneous

constructed thermoplastic polymer plain bearing with additives, the additives being, for example, fillers, solid lubricants and short fibers, each of which is distributed in the polymer matrix. Furthermore, there are between the outer and inner tabs

PTFE seals provided. The problem on which the present invention is based is the creation of a link chain of the type mentioned at the beginning which does not require initial lubrication or lubrication during operation and in particular nevertheless at least the same loads

can withstand as known from the prior art

Bush conveyor chains. Monitoring of the plain bearings is also to be made possible as an option. Uses of the link chain should also be specified.

According to the invention, this is achieved by a link chain of the type mentioned at the outset with the characterizing features of claims 1 and / or 13 and / or 15 and by use with the

Features of claim 19 achieved. The subclaims relate to preferred embodiments of the invention.

According to claim 1 it is provided that each of the plain bearings has a support layer and a sliding layer, each one

Include plastic-based matrix material. According to claim 15, it is provided that each of the seals comprises a plastic-based sealing material and a solid lubricant. This design of the plain bearings and the seals allows the link chain to be used completely free of lubricants.

The resulting advantages are the protection of

Resources such as, in particular, avoiding costs for automatic lubrication devices and / or a manual one

Relubrication and / or for lubricants. Another benefit is protecting the environment, especially avoiding it

Pollution of the environment from the lubricants, the avoidance of contamination of the housing due to lubricant residues and the prevention of contamination of the conveyed material Lubricant residue. Furthermore, no access to lubrication is required during operation.

Another advantage is that existing, previously lubricated chains can be replaced with a completely lubricant-free system with the same external dimensions.

Furthermore, the plain bearings can have very good chemical resistance due to the plastic matrix material.

Furthermore, by using seals which comprise a plastic-based sealing material and a solid lubricant, the counter surfaces of the seals no longer have to be adjusted by mechanical processing or by additional components.

There is the possibility that the support layer is arranged radially on the outside and faces the hinge bush, whereas the sliding layer is arranged radially on the inside and the hinge pin

is facing.

It can be provided that the base layer and the sliding layer are connected to one another by the matrix material. In particular, the matrix material can be a synthetic resin or a thermosetting plastic or comprise a synthetic resin or a thermosetting plastic, in particular wherein the matrix material is an epoxy resin or comprises an epoxy resin. As a result, the layers are firmly connected to one another.

There is a possibility that the sliding layer is better

Sliding properties than the base layer and / or that the base layer has a higher load capacity than the sliding layer. By varying the layer thickness, the plain bearings can be attached to special Load cases and areas of application are adapted. This means that the plain bearing can be used depending on the load and permissible wear

can be flexibly built up layer by layer, in particular the proportion of the sliding layer and the base layer in the total thickness of the sliding bearing can be variably determined depending on the application. The permissible wear path depends on the layer thickness of the sliding layer, after its removal the function of the

Plain bearing is no longer guaranteed. For example, a comparatively thick base layer and a comparatively thin sliding layer result in a high load-bearing capacity and a low permissible wear, while a comparatively thin base layer and a comparatively thick sliding layer result in a low load-bearing capacity and a large permissible wear.

It can be provided that the sliding layer and / or the

Base layer comprise an integrated solid lubricant,

especially boron nitride, M0S2, graphite or PTFE. By the

solid lubricant can transfer lubrication of the chain link can be effected, in which solid lubricant particles are embedded in the roughness peaks of the respective counterpart.

There is a possibility that the sliding layer and / or the

Base layer consist of endlessly wound fibers, in particular made of polyester, aramid, carbon, glass or PTFE. Due to the reinforcement by continuous fibers, with a suitable structure of the layers, a surface pressure with dynamic loads of up to 140MPa may be permissible. In particular, one with

corresponding plain bearing provided articulated chain, in contrast to articulated chains known from the prior art, equipped with plain bearings, with an articular surface pressure of up to 50 MPa. A suitably designed link chain can thus withstand at least the same loads as the bush conveyor chains known from the prior art.

Alternatively or additionally, it can be provided that the sliding layer comprises non-endless fibers, in particular fibers made of PTFE or polyester, and optionally comprises an additive, for example PTFE. This can also have a positive influence on the sliding properties of the sliding layer.

There is a possibility that one, more, or each of the

Plain bearing has more than two layers. This allows the plain bearings to be adapted even more flexibly to the purpose of the link chain.

It can be provided that one, several or each of the

Plain bearing a lip seal or a dirt lip as well

alternatively or additionally comprises a chamfer. A lip seal or a dirt lip can prevent dirt from entering the joint and are arranged in particular on the inside diameter of the plain bearing. A chamfer on the end faces of the plain bearing can improve its mountability and is arranged in particular on the outer diameter of the plain bearing.

There is a possibility that the sliding layer of the slide bearing can be machined. As a result, exact, highly precise bearing clearances can be set if necessary.

According to claim 13 it is provided that one, more or each of the slide bearings comprises an electrical conductor which is arranged in particular between the support layer and the sliding layer. It can be provided that a section of the electrical conductor can come into contact with the hinge pin due to wear by removing the sliding layer and thereby the Resistance between one end of the electrical conductor and the hinge pin is reduced. If the sliding layer has been substantially completely removed by wear, a section of one can be arranged between the sliding layer and the supporting layer

electrical conductor come into contact with the hinge pin. It can thus be detected by a suitable monitoring device that the resistance between one end of the

electrical conductor and the hinge pin reduced, so that the monitoring device wear of the plain bearing

can signal.

There is a possibility that the sealing material is a

Sealing material is based on polyurethane and / or that the

Solid lubricant is boron nitride, M0S2, graphite or PTFE. Self-lubrication of the seal can thus be ensured by the combination of at least one or more solid lubricants and a suitable base material.

According to claim 19, an articulated chain according to the invention can be used as an escalator chain or as a pallet chain or as a step chain or as a scraper chain. The applications mentioned are examples. A link chain according to the invention can in principle be used in all industrial areas.

Further features and advantages of the present invention will become clear from the following description of preferred exemplary embodiments with reference to the accompanying figures. 1 shows a section through a chain link of a first one

Embodiment of a link chain according to the invention;

2 shows a detail according to arrow II in FIG. 1;

3 shows a section through a part of a plain bearing

Articulated chain according to FIG. 1; 4 shows a detail according to arrow IV in FIG. 3;

5 shows a section through part of a plain bearing of a second embodiment of a link chain according to the invention;

6 shows a section through a chain link of a link chain according to the prior art, which is designed as an oil-lubricated bush conveyor chain;

7 shows a section through a chain link of a link chain according to the prior art, which is designed as a grease-lubricated bush conveyor chain;

8 shows a section through a chain link with a

Articulated chain provided with plain bearings according to the prior art.

In the figures, identical or functionally identical parts are provided with the same reference symbols. The embodiment shown in Fig. 1 and Fig.2

Link chain according to the invention comprises a plurality of

Outer plates 4, two of which are opposite each other in the chain cross direction, and a plurality of inner plates 3, of which two are also opposite each other in the chain cross direction. The embodiment further includes one

A plurality of hinge pins 2, each of which are connected in a rotationally fixed manner to two outer link plates 4 lying opposite one another in the chain transverse direction, and a plurality of hinge bushings 1 which are each connected in a rotationally fixed manner to two inner link plates 3 lying opposite one another in the chain transverse direction. At a

Movement of the chain link find a rotation of the link bushing 1 relative to the link pin 2 and a pivoting of the

Inner plates 3 relative to the outer plates 4 instead. Each of the articulated bushings 1 partially surrounds one of the articulated bolts 2. A hollow cylindrical plain bearing 5 is located between an articulated bushing 1 and an articulated bolt 2

arranged. The slide bearing 5 is rotatably connected to the bush 1, in particular pressed, whereas the hinge pin 2 is rotatable in the slide bearing 5. Each of the slide bearings 5 comprises a radially outer one, which faces the joint bushing 1

Base layer 6 and a radially inner sliding layer 7 facing the hinge pin 2 (see FIG. 2).

There is a possibility that the plain bearing 5 has more than two layers.

Both the base layer 6 and the sliding layer 7 each comprise a plastic-based matrix material. The matrix material can be and is a synthetic resin or a thermosetting plastic or comprise a synthetic resin or a thermosetting plastic especially an epoxy resin. The base layer 6 and the sliding layer 7 are connected to one another by the matrix material.

Solid lubricants such as M0S2, graphite or PTFE can be integrated into the plastic matrix of the sliding layer 7. The sliding layer 7 can also consist of endlessly wound fibers

for example include polyester, aramid, carbon, glass or PTFE. In particular, endlessly wound fibers made of polyester can be provided. Alternatively, the sliding layer 7 can comprise non-continuous fibers, for example made of PTFE, polyester or the like, and further additives such as PTFE.

In the plastic matrix of the base layer 6 can also

Solid lubricants such as boron nitride, M0S2, graphite or PTFE can be integrated. Furthermore, the base layer 6 can also comprise endlessly wound fibers made of polyester, aramid, carbon or glass. In particular, endlessly wound glass fibers can be provided.

The composition of the layers can in particular be selected such that the sliding layer 7 has better sliding properties than the supporting layer 6 and that the supporting layer 6 has a higher load capacity than the sliding layer 7. In this way, by specifically influencing the structure of the layers, the plain bearing can be adapted to the purpose of the link chain. In particular, the joint chain can be designed with a suitable structure of the layers with a joint surface pressure of up to 50 MPa.

For example, the composition of the sliding layer 7 can be selected such that it can be machined. This enables the bearing clearance to be set precisely. This can also be done by a suitable choice of the thickness of the layers

Plain bearings 5 can be adapted to the application of the link chain. The one shown in Fig.3 and Fig.4

The embodiment is the thickness d6 of the base layer 6 in

Essentially equal to the thickness d of the sliding layer 7. In the embodiment shown in FIG. 5, the thickness d6 of the base layer 6 is significantly greater than the thickness dz of the sliding layer 7. The thickness dz of the sliding layer 7 can in particular be between 0.2 mm and 5 mm. 0 mm. The thickness dz of the sliding layer 7 can at the

Application of the link chain can be adapted.

The link chain according to the invention can, for example, as

Escalator chain, pallet chain or step chain can be used. With a step chain is according to the relevant standard

maximum distance between the steps of 6 mm permitted. If a gap of 2 mm is assumed between the steps when the step chain is new, a possible one results from this

Wear path per step of 4 mm.

Depending on the division of the chain, three or four chain links are provided between the stages with typical division. The 4 mm of the

Wear paths can thus be divided into three to five plain bearings, so that the individual plain bearings have wear paths of 0.8 mm to 1.3 mm.

The link chain according to the invention can also be used, for example, as a scraper chain for bulk goods. In such

Use cases of more than 1 mm are often unproblematic. The limitation of the permissible wear often does not result from the plain bearing, but rather, for example, from the design of the tooth shape of the chain wheel. So there are sliding layers of several millimeters thick conceivable. Typical hardness depths and thus the wear limit for heavy bulk material chains without plain bearing technology are 3 mm and more.

In the embodiment of an articulated chain according to the invention shown in FIGS. 1 and 2, a seal 8 is arranged between adjacent inner and outer plates 3, 4. Each of the seals 8 comprises a plastic-based sealing material and a solid lubricant integrated in the sealing material. The solid lubricant can

for example, boron nitride, M0S2, graphite or PTFE. The sealing material can be a polyurethane-based material.

The lubrication of the slide bearings 5 and the seals 8 during the operation of the link chain is done by a so-called transfer lubrication

realized. The sit in the plain bearing material

or integrated into the sealing material

Solid lubricants in the roughness tips of the respective

Counterpart as soon as there is initial wear when the chain runs in. Because of this, neither the slide bearing 5 nor the seals 8 require a lubricant applied by additional measures during the entire life of the link chain.

Chamfers 9 can be provided on the end faces of both layers of the sliding bearing 5 in order to improve the assemblability (see FIG. 4). Alternatively, lip seals or dirt lips, not shown, can be provided on the end faces of the slide bearing. In particular, these can be produced directly with the plain bearing, so that they consist of the same material as the plain bearing. This has the advantage that they are very wear-resistant and do not lose their position in operation. There is also the possibility of an electrical conductor (not shown) on one, several or each of the plain bearings,

for example, to provide a conductor in the form of a thin metallic wire. The electrical conductor can in particular be arranged between the base layer and the sliding layer. This can be achieved comparatively easily in terms of production technology if the two layers are produced in succession, for example by winding the continuous fibers.

If the sliding layer has essentially been completely removed by wear, the electrical conductor comes into contact with the joint pin. So it can be local in the area of the corresponding

Chain joint, a battery-operated monitoring device can be arranged, for example, in a recess in one of the tabs, which monitors the resistance between one end of the electrical conductor and the joint pin. If the resistance is due to direct contact of a portion of the conductor with the

Joint pin is greatly reduced, the

Monitoring device for wear of the plain bearing

signal.

Claims

claims:

1. Articulated chain, comprising a plurality of outer plates (4), two of which are opposite each other in the chain cross direction, - a plurality of inner plates (3), of which two are opposite each other in the chain transverse direction, a plurality of joint pins (2), each rotatably with two each other in the chain cross direction

opposite outer link plates (4) are connected, - a plurality of hinge bushings (1), each rotatably with two in the chain cross direction

opposite inner plates (3) are connected, the hinge bushings (1) each surrounding a hinge pin (2) at least in sections - a plurality of slide bearings (5), each between

a hinge pin (2) and a hinge bush (1) are arranged, characterized in that each of the slide bearings (5) has a support layer (6) and a slide layer (7), each of which comprises a plastic-based matrix material.

2. Articulated chain according to claim 1, characterized in that the support layer (6) is arranged radially on the outside and the

Articulated bushing (1) faces, whereas the sliding layer (7) is arranged radially on the inside and the articulated pin (2)

is facing.

3. Articulated chain according to one of claims 1 or 2, characterized in that the support layer (6) and the sliding layer (7) are interconnected by the matrix material.

4. Articulated chain according to one of claims 1 to 3, characterized

characterized in that the matrix material is a synthetic resin or a thermoset or a synthetic resin

or comprises a thermoset, in particular wherein the matrix material is an epoxy resin or comprises an epoxy resin.

5. Articulated chain according to one of claims 1 to 4, characterized

characterized that the sliding layer (7) better

Sliding properties than the base layer (6) and / or that the base layer (6) has a higher load capacity than the base layer (7).

6. Articulated chain according to one of claims 1 to 5, characterized

characterized in that the sliding layer (7) and / or the

Base layer (6) comprise an integrated solid lubricant, in particular boron nitride, M0S2, graphite or PTFE.

7. Link chain according to one of claims 1 to 6, characterized

characterized in that the sliding layer (7) and / or the

Base layer (6) comprise endlessly wound fibers,

especially made of polyester, aramid, carbon, glass or PTFE.

8. Articulated chain according to one of claims 1 to 7, characterized

characterized in that the sliding layer (7) is not endless

Fibers, in particular fibers made of PTFE or polyester, and optionally includes an additive, for example PTFE.

9. Articulated chain according to one of claims 1 to 8, characterized in that the sliding layer (7) is arranged in each case on the side of the sliding bearing facing the articulated bolt (2), the supporting layer (6) being connected in particular in a rotationally fixed manner to the articulated bushing (1) , preferably pressed, is.

10. Articulated chain according to one of claims 1 to 9, characterized

characterized in that one, several or each of the slide bearings (5) has more than two layers.

11. Link chain according to one of claims 1 to 10, characterized

characterized in that one, more or each of the slide bearings (5) comprises a lip seal or a dirt lip and alternatively or additionally a chamfer (9).

12. Articulated chain according to one of claims 1 to 11, characterized

characterized in that the sliding layer (7) of the sliding bearing (5) can be machined.

13. Articulated chain according to the preamble of claim 1 or according to one of claims 1 to 12, characterized in that one, more or each of the sliding bearings (5) comprises an electrical conductor, in particular between the support layer (6) and the sliding layer (7 ) is arranged.

14. Articulated chain according to claim 13, characterized in that a portion of the electrical conductor by removing the sliding layer (7) due to wear can come into contact with the hinge pin (2) and thereby the resistance between one end of the electrical conductor and the

Hinge pin (2) reduced.

15. Link chain, comprehensive a plurality of outer link plates (4), two of which are opposite each other in the chain cross direction, a plurality of inner link plates (3), of which two are opposite each other in the chain cross direction, a plurality of hinge pins (2), each of which is non-rotatable with two in the chain cross direction each other

opposite outer plates (4) are connected, a plurality of hinge bushings (1), each rotatably with two in the chain cross direction

opposite inner plates (3) are connected, the joint bushings (1) each surrounding a joint pin (2), a plurality of seals (8), one of which is arranged between adjacent inner and outer plates (3, 4), characterized that each of the seals (8) a sealing material on a plastic basis and a

Solid lubricant includes.

16. Articulated chain according to claim 15, characterized in that the sealing material is a sealing material

Is polyurethane base and / or that the solid lubricant

Boron nitride, M0S2, graphite or PTFE.

17. Link chain according to one of claims 15 or 16, characterized in that the link chain is a link chain according to one of claims 1 to 14.

18. Link chain according to one of claims 1 to 17, characterized in that the link chain is designed so that it can be used completely lubricant-free.

19. Use of a link chain according to one of claims 1 to 18, characterized in that the link chain

is used in particular as an escalator chain or as a pallet chain or as a step chain or as a scraper chain.