Pulley for traction mechanism

Abstract

The invention relates to a pulley for a traction mechanism (2) of an elevator, comprising at least one bearing (3), a main body (4) and a running surface housing (5) having a first plastic, the at least one bearing (3) being held by the main body (4), an intermediate layer (6) being arranged between the main body (4) and the running surface housing (5) and being connected to the main body (4) and the running surface housing (5), wherein the intermediate layer (6) comprises a second plastic, which is different from the first plastic.

Description

Technical Field

[0001] The invention relates to a pulley for a traction mechanism of an elevator, an elevator and a method for manufacturing a pulley. Background Art

[0002] Pulleys and some of their manufacturing methods are disclosed in documents EP 2679532 A1, WO 2020234172 A1, WO 90 / 04730 A1, EP 2684831 A1, EP 1902994 A1, WO 02 / 46086 A1 and GB 1121220.

[0003] According to the prior art, a pulley can have a main body and a running surface housing made of a first plastic, wherein at least one bearing is held by the main body.

[0004] Modern elevators often require running surface housings made of plastic, as plastic can be processed efficiently by injection molding and is lightweight. The plastic used for the running surface housing can be specifically selected to achieve highly specific properties for the running surface housing or the running surface itself. This can, for example, achieve particularly low friction or a certain degree of vibration damping.

[0005] In many cases, a challenge here is to process heterogeneous plastics with a high degree of process safety and reliability in order to actually achieve the desired properties of the running surface housing. Summary of the Invention

[0006] The object of the present invention is therefore to specify a pulley for an elevator and a method for producing a pulley for an elevator, in which the desired properties, in particular low friction, can be reliably achieved.

[0007] Regarding the pulley, the invention is achieved by one or more of the features disclosed herein, namely that an intermediate layer connected to the main body and the running surface housing is present between the main body and the running surface housing, wherein the intermediate layer contains a second plastic that is different from the first plastic of the running surface housing.

[0008] Regarding the method, the object is achieved by one or more of the features disclosed herein, namely by the following steps: - providing a body, preferably together with at least one bearing fitted therein or to be fitted therein, - manufacturing the running surface housing at least partially from a first plastic, and An intermediate layer is produced between the main body and the running surface housing at least partially from a second plastic material that is different from the first plastic material.

[0009] By providing an intermediate layer connected to the main body and the running surface housing according to the invention, the production of the main body and the running surface housing can be separated. This allows for reliable production of the pulley even when the physical characteristics of the running surface housing are incompatible with those of the main body.

[0010] The connection of the materials can be a form fit, an interference fit or the result of a physical and / or chemical bond (integration).

[0011] For example, if the material of the running surface shell—which differs from the material of the main body—has particularly strong shrinkage, this can be compensated by the intermediate layer. For example, tests conducted by the applicant have shown that if the material of the running surface shell has strong shrinkage while the material of the main body does not shrink or shrinks only slightly, the running surface shell can break because strong internal stresses remain in the running surface shell, which can exceed the strength of the running surface shell during use.

[0012] For example, if the adhesion of the running surface housing material to the main body material is not ideal, then in certain embodiments, the intermediate layer can ensure that the intermediate layer forms a sufficiently strong connection (integral connection and / or interference fit connection and / or form fit connection) not only to the main body but also to the running surface housing.

[0013] According to the invention, the intermediate layer is directly connected to the main body and the running surface housing, so that at most one adhesion promoter is present at the contact surfaces between the intermediate layer and the main body and between the intermediate layer and the running surface housing, without, for example, further intermediate layers.

[0014] Particularly preferably, the main body is produced in one piece from one material, although, for example, a multi-layer embodiment is also conceivable in principle.

[0015] The running surface housing may preferably completely surround and / or cover the main body and the intermediate layer in the circumferential direction.

[0016] Seen in axial cross-section, the running surface housing may preferably completely surround and / or cover the main body and the intermediate layer.

[0017] Particularly preferably, it can be provided that the running surface housing can be spaced apart from the main body over the entire region by the intermediate layer.

[0018] The material of the main body may preferably be metal, in particular steel, or plastic.

[0019] The at least one bearing used may be, for example, one or more rolling bearings, with sliding bearings also being conceivable.

[0020] The function of the body is to hold at least one bearing.

[0021] In a particularly preferred embodiment, the running surface housing can consist of a different material than the intermediate layer.

[0022] The statement that the first plastic is different from the second plastic can preferably be understood to mean that the first plastic and the second plastic are not completely identical. Particularly preferably, the second plastic can be another plastic type different from the first plastic, for example, the first plastic can be polyethylene, and the second plastic can be polyamide.

[0023] The method steps according to the invention for producing a pulley do not necessarily have to be carried out in the order described above.

[0024] For example, the intermediate layer can also be produced before the production of the running surface housing and / or the provision of the main body.

[0025] Similarly, the production of the intermediate layer and / or the production of the running surface shell can also take place before the provision of the main body.

[0026] However, the method steps are preferably performed in the order described.

[0027] The installation of the at least one bearing in the body can take place before, during or after the implementation of the method according to the invention for producing a pulley.

[0028] According to the invention, protection is also sought for elevators having at least one pulley.

[0029] The invention can be used in all types of elevators, in particular passenger elevators and freight elevator applications.

[0030] The pulley is particularly preferably free-running, ie not driven.

[0031] Advantageous developments of the invention are described below.

[0032] The first plastic can preferably be a thermoplastic, for example polyethylene, particularly preferably ultra-high molecular weight polyethylene. Ultra-high molecular weight polyethylene is characterized by particularly low friction. Particularly preferably, it can be ultra-high molecular weight polyethylene (PE-UHMW) and / or ultra-high density polyethylene (PE-UHD), also known as PE-UHMW.

[0033] Alternatively or additionally, the first plastic used can be, in particular, polyolefin, polymethyl methacrylate (POM, also known as polyacetal), polyamide (PA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), thermoplastic elastomer (TPE), polyketone (PK), fluoropolymer (e.g. polytetrafluoroethylene, PTFE) and / or polyetherimide (PEI) and / or polyester (PES).

[0034] Alternatively or additionally, the first plastic used may be a thermosetting plastic, such as phenolic resin, polyester resin and / or silicone resin.

[0035] Alternatively or additionally, the first plastic used may be an elastomer, for example polyurethane (PU) and / or ethylene propylene diene monomer (EPDM).

[0036] The first plastic may account for more than 50%, preferably more than 75%, particularly preferably more than 90%, and especially preferably more than 99% of the running surface housing.

[0037] The second plastic can be a thermoplastic, preferably a polyamide, particularly preferably a recycled polyamide.

[0038] The second plastic may account for more than 20% of the intermediate layer, preferably more than 30%, particularly preferably more than 40%.

[0039] The second plastic may account for less than 80% of the intermediate layer, preferably less than 70%, particularly preferably less than 60%.

[0040] Particularly preferably, the intermediate layer can consist of the second plastic and the filler in approximately equal amounts by weight.

[0041] The first plastic and / or the second plastic may preferably be a plastic that can be processed by injection molding.

[0042] The intermediate layer can preferably have a filler, in particular preferably in the form of a glass fiber filling.

[0043] The first plastic and / or the second plastic may contain one or more additives, for example additives for modifying the tribological properties, such as dry lubricants, silicone oils, friction-active additives or mineral fillers.

[0044] The main body may comprise an annular groove in which the intermediate layer and / or the running surface housing is at least partially arranged. The running surface housing and / or the intermediate layer may thus be connected to the main body in a form-fitting manner.

[0045] Similarly, the running surface housing can be arranged at least partially in the annular recess of the intermediate layer in order to form a positive connection between the running surface housing and the intermediate layer.

[0046] Within the scope of the present invention, a further integral connection and / or an interference fit connection between the running surface housing and the intermediate layer or between the intermediate layer and the main body is not excluded.

[0047] Naturally, instead of a single annular groove or annular recess, a plurality of annular grooves and / or a plurality of annular recesses can also be used.

[0048] At least one bearing can be integrated into the main body. In other words, the outer ring of at least one bearing can form the main body.

[0049] The running surface housing may comprise a running surface which preferably comprises a first wedge-shaped profile or is configured in another way.

[0050] In principle, however, flat belts without a profile can also be used within the scope of the invention.

[0051] The traction mechanism cooperating with the at least one pulley may comprise at least one steel cable, which is preferably embedded in the belt.

[0052] At least one traction mechanism in the form of a wire rope may be sheathed.

[0053] The belt may include an inner profile that mates with the running surface of the running surface housing.

[0054] The inner contour may include a second wedge-shaped contour.

[0055] The running surface corresponds to the inner contour, preferably wherein the first wedge-shaped contour corresponds to the second wedge-shaped contour.

[0056] In certain embodiments, the running surface comprises a first wedge-shaped profile that cooperates with one or more steel cables as traction means, wherein the steel cables can be located in recesses of the first wedge-shaped profile.

[0057] The first and / or second wedge-shaped profile may preferably comprise a plurality of wedge-shaped portions, for example having a triangular appearance in cross-section, preferably with rounded edges.

[0058] These wedges, in particular when they engage with the mating contour, can provide a particularly secure lateral guidance of the traction mechanism on the pulley while simultaneously achieving good vibration damping properties.

[0059] Particularly preferably, the running surface housing and / or the intermediate layer can be produced by injection molding.

[0060] In a particularly preferred embodiment, the connection of the intermediate layer to the main body and / or the connection of the intermediate layer to the running surface housing is produced by producing the intermediate layer.

[0061] Therefore, when manufacturing the intermediate layer, the main body and / or the running surface shell are preferably already in place, and the connection between the intermediate layer and the main body and / or between the intermediate layer and the running surface shell is formed in the step of manufacturing the intermediate layer.

[0062] Particularly preferably, the running surface housing can be positioned around the main body in a defined relative position to the pulley before the intermediate layer is produced.

[0063] The running surface housing is positioned around the main body in the relative position of the setting and can be understood in this way that positioning is subject to the inaccuracy of common manufacturing technology. In addition, in the process of producing the intermediate layer, the running surface housing may be subjected to the deviation relevant to the production process.

[0064] The positioning of the running surface housing in the predetermined relative position around the main body can take place by inserting the main body and / or the running surface housing into a molding tool (second molding tool), in particular an injection molding tool.

[0065] All percentage figures are to be understood as percentages by weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Further advantages and details of the present invention can be clearly seen from the accompanying drawings and the related description of the drawings. In the drawings: 1a to 1d schematically show an embodiment of a pulley according to the invention in different views; 2a to 2f show schematic diagrams for explaining an exemplary embodiment of the method for producing a pulley according to the invention; Figure 3 Schematically shows an embodiment of an elevator according to the invention; 4 a to 4 d schematically show another embodiment of a pulley according to the invention in different views; Figures 5a to 5d schematically shows another embodiment of a pulley according to the invention in different views; and Figures 6a to 6d A further exemplary embodiment of a pulley according to the invention is schematically shown in different views. DETAILED DESCRIPTION

[0067] An exemplary embodiment of a pulley 1 according to the invention is schematically shown in front view in FIG. 1 a , in cross-section in FIG. 1 b , in side view in FIG. 1 c and in perspective view in FIG. 1 d .

[0068] The pulley 1 comprises a body 4 consisting of steel, into which two bearings 3 (here ball bearings) are pressed. The running surface 7 of the pulley 1 is formed by a running surface shell 5 , which is connected to the body 4 via an intermediate layer 6 .

[0069] In this embodiment, the running surface housing 5 is made of ultra-high molecular weight polyethylene (first plastic). Preferably, the content of any additive is less than 1%.

[0070] The middle layer 6 is made of recycled polyamide with glass fiber filling. Preferably, the content of any additives is less than 1%.

[0071] The running surface 7 comprises a first wedge-shaped profile, which can cooperate with one or more steel cables as traction means 2 .

[0072] As in Figure 1b As can be seen in FIG, the main body has a recess on its outer surface, in which the intermediate layer 6 is partially arranged, so that the intermediate layer is connected to the main body 4 at least in a form-fitting manner.

[0073] Similarly, the running surface housing 5 is partially arranged in the annular recess of the intermediate layer 6 , so that here too at least one form-fitting connection is formed.

[0074] In this embodiment, the bottom of the grooves and / or recesses is wavy, ie not completely flat. The wave crests and troughs correspond in their axial position to the crests and troughs of the first wedge-shaped profile of the running surface 7, as is generally known from WO 2020 / 234172 A1.

[0075] Figures 2a to 2f The steps of an exemplary embodiment of the invention of a method for producing a pulley 1 are schematically explained.

[0076] Figure 2a A first forming tool or mold 11 is shown. In the context of an injection molding process, this mold is filled with ultra-high molecular weight polyethylene to the point where Figure 2b The status shown.

[0077] After the running surface shell 5 manufactured in this manner has cooled, it is taken out of the first mold 11 ( Figure 2c Shrinkage—a tightening of the geometry—occurs in the mold 11 and after demolding. If the main body 4 provided here does not shrink or shrinks only slightly, the shrinkage of the running surface housing 5 will be hindered, which can lead to stresses within the material of the running surface housing 5. These stresses alone, combined with any additional stresses that may arise during use, could exceed the material's strength, leading to fracture of the running surface housing 5.

[0078] Subsequently, the provided main body 4 and running surface housing 5 are placed in the second mold 12, i.e. in such a way that the running surface housing 5 is already in the relative position set by the pulley relative to the main body 4, although this relative position may still change to a certain extent, for example due to a subsequent additional injection molding process (Figure 2d).

[0079] As shown in FIG. 2 e , the gap between the main body 4 and the running surface housing 5 is filled with a second plastic, in this embodiment a recycled polyamide with glass fiber filling.

[0080] After the intermediate layer 6 has cooled and been demoulded, the main body 4 , the intermediate layer 6 and the running surface housing 5 are present as a composite body, the state of which after demoulding is shown in FIG. 2 f .

[0081] To produce the pulley 1 , the bearing 3 is subsequently pressed into the body 4 in a manner known per se.

[0082] Figure 3 An embodiment according to the invention of an elevator 10 is schematically shown, comprising a plurality of pulleys 1 cooperating with a traction mechanism 2 .

[0083] The pulleys are free-sliding in this embodiment.

[0084] The traction mechanism can be, for example, a steel cable, a sheathed steel cable, a belt with an embedded steel cable, or another conceivable type of traction mechanism suitable for the application. For example, belts with glass and / or aramid fibers as short fibers, staple fibers, twisted fibers, continuous fibers, and / or filaments can also be used.

[0085] Figures 4a to 4d A further embodiment according to the present invention is schematically shown, wherein compared to the embodiment according to Figures 1a to 1d The embodiment of the invention adopts a double row bearing 3. In addition, the embodiment is similar to Figures 1a to 1d Those contents.

[0086] Figures 5a to 5d A further embodiment according to the present invention is schematically shown, wherein compared to the embodiment according to Figures 1a to 1d The embodiment of uses only one bearing 3. Otherwise, this embodiment is similar to Figures 1a to 1d Those contents.

[0087] Figures 6a to 6d A further embodiment according to the present invention is schematically shown, wherein compared to the embodiment according to Figures 1a to 1d The exemplary embodiment provides that the running surface 7 cooperates with a belt 9 as the traction mechanism 2 instead of a steel cable.

[0088] Belt 9 in Figure 6b Schematically shown in addition.

[0089] It should be noted that the steel cable 8 is embedded in the belt 9 .

[0090] The belt comprises an inner profile which comprises a second wedge-shaped profile and which cooperates with the running surface 7 of the running surface housing 5 .

[0091] The first wedge-shaped profile of the running surface 7 corresponds to the second wedge-shaped profile of the inner contour of the belt 9 .

[0092] besides, Figures 6a to 6d An embodiment similar to Figures 1a to 1d Those contents.

[0093] It should be mentioned that according to the invention, flat belts without an inner contour can also be used, wherein the pulley 1 can be adapted to such flat belts in a manner known per se, as in the prior art.

[0094] Reference Signs List 1 pulley 2 traction mechanism 3 bearings 4 main body 5 running surface housing 6 Middle Layer 7 running surfaces 8 steel cables 9 belts 10 Elevator 11First Mold 12 Second mold

Claims

1. A pulley for a traction mechanism (2) of an elevator, comprising at least one bearing, a body and a running surface housing having a first plastic, wherein the at least one bearing is held by the body, an intermediate layer connected to the body and the running surface housing is present between the body and the running surface housing, wherein the intermediate layer comprises a second plastic different from the first plastic.

2. The pulley according to claim 1, wherein The first plastic is a thermoplastic.

3. The pulley according to claim 1, wherein The first plastic accounts for more than 50% of the running surface shell.

4. The pulley according to claim 1, wherein The second plastic is a thermoplastic.

5. The pulley according to claim 1, wherein The second plastic accounts for more than 20% of the intermediate layer.

6. The pulley according to claim 5, wherein The second plastic accounts for less than 80% of the intermediate layer.

7. The pulley according to claim 5, wherein The intermediate layer has a filler.

8. The pulley according to claim 1, wherein The running surface housing includes a running surface including a first wedge-shaped profile.

9. The pulley according to claim 1, wherein The at least one bearing is integrated into the body.

10. An elevator comprising at least one pulley according to claim 1.

11. The elevator of claim 10, further comprising a traction mechanism engaged with the at least one pulley, the traction mechanism comprising at least one steel cable.

12. The elevator of claim 11, wherein the running surface of the at least one pulley has a wedge-shaped profile, the traction mechanism comprises a belt in which a steel cable is embedded, and the belt includes an inner profile that cooperates with the running surface of the running surface housing.

13. The elevator of claim 12, wherein the inner profile comprises a second wedge-shaped profile. The elevator according to claim 13 , wherein the running surface corresponds to an inner contour.

15. A method for manufacturing a pulley for an elevator traction mechanism, comprising the following steps: - providing a body in which at least one bearing is already assembled or is to be assembled, - manufacturing the running surface housing at least partially from a first plastic, and An intermediate layer between the main body and the running surface housing is at least partially produced from a second plastic material that is different from the first plastic material.

16. The method according to claim 15, wherein at least one of the running surface shell and / or the intermediate layer is manufactured by injection molding. 17 . The method according to claim 15 , wherein the connection of the intermediate layer to the main body and / or the connection of the intermediate layer to the running surface housing is produced by producing the intermediate layer.

18. The method of claim 15, wherein the running surface housing is positioned about the body in a desired relative position to a pulley before the intermediate layer is manufactured.

19. The pulley of claim 2, wherein the first plastic is ultra high molecular weight polyethylene.

20. The pulley of claim 4, wherein the second plastic is polyamide.

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