Plain bearing assembly having a rail and a carriage

Abstract

The present invention relates to a sliding bearing assembly (1) comprising a rail and a carriage (20), the rail having an elongated rail body (10) in the longitudinal direction, one cross section of which is provided with a cylindrical guide portion (11), the carriage (20) having a carriage body provided with a cylindrical passage (22) corresponding to the guide portion (11) for receiving the guide portion (11), the inner surface of the passage (22) being formed by a sliding element made of a sliding material, the inner surface of the passage allowing the carriage (20) to slide longitudinally against the guide portion (11) when the sliding bearing assembly is in an operating state, the sliding element being manufactured together with the carriage body as an integral carriage part made of a plastic material.

Description

[Technical Field]

[0001] The present invention relates to a plain bearing assembly including a substantially straight rail and a carriage displaceable on the rail in the longitudinal direction, the carriage being guided on the rail by a guide portion. The present invention also relates to a carriage of the plain bearing assembly and a method for manufacturing the carriage. [Background technology]

[0002] The sliding bearing assembly is required whenever a mechanical element needs to be moved along a substantially straight line with minimal time and energy expenditure, for example, in the fields of automated manufacturing, material processing machines, measuring machines, medical technology, and filling and packaging. Here, the surface of the guiding element (rail) slides on the surface of the moving guided element (carriage), preferably without additional lubricant. It goes without saying that the guiding element, i.e., the rail, is significantly longer in the longitudinal direction than the guided element, i.e., the carriage, thereby resulting in a practical configuration. This can be ensured, for example, conventionally by a rail having a longitudinal extent at least five times the longitudinal extent of the carriage. In intended use, the rail is usually fixed to an apparatus, e.g., a wall or machine, by a fixed surface, particularly a surface remote from the carriage, while the carriage, linearly guided by the rail, is movable relative to the rail and thus the apparatus. The fixed surface conventionally has a flat surface portion configured to contact the apparatus in the intended use. The flat surface portion may be continuous or may have small portions spaced apart from one another, and the flat surface portion preferably constitutes at least 50% of the area of ​​the fixed surface. Rails traditionally have a cylindrical guide portion offset from the fixed surface. The sliding surface material combinations used are usually metal-plastic or plastic-plastic. Linear plain bearing assemblies have often proven to be an advantageous alternative to linear ball bearings. In a typical plain bearing assembly, the carriage traditionally has a mounting surface on which a working device, e.g., a machine component that is moved linearly in the longitudinal direction, is arranged and fastened. A fastening channel extending perpendicular to the longitudinal direction through the carriage body preferably opens into the mounting surface. A fastening means, e.g., a screw, can be guided through the fastening channel, and during the intended use of the plain bearing assembly, the screw presses with its screw head against the face of the carriage body opposite the mounting surface and is screwed into the working device. The mounting surface preferably has a flat mounting surface, and the fastening channel preferably opens into the mounting surface.The carriage is often generally rectangular, with one of the faces of the rectangular carriage configured as a mounting surface. A passage extending longitudinally through the carriage body is provided in the carriage body for receiving the cylindrical guide portion of the rail. In the rectangular configuration of the carriage, the passage preferably extends parallel to, or at least preferably on, four of the six faces of the rectangular parallelepiped, or on at least the flat mounting surface provided, and in particular perpendicular to the fastening channel. The fastening channel is offset transversely from, and thus spaced apart from, the passage.

[0003] A sliding bearing assembly having a rail and a carriage made of metal is known. A passage for receiving a guide portion of the rail extends through the carriage body, and the inner surface of the passage is formed by a sliding element made of plastic material. Patent Document 1 discloses an example of a sliding element in such a sliding bearing assembly. A similar sliding bearing assembly consisting of a rail and a carriage is sold by the applicant under the trade name "drylin." The carriage body here can be made of die-cast zinc, aluminum, or stainless steel. A special sliding material is provided for the sliding element. The sliding element forms a passage in contact with the carriage body. Thus, the carriage body has a passage channel in which the sliding element and the passage are arranged, and the sliding element contacts the inner surface of the passage channel. Manufacturing such a sliding bearing assembly requires considerable effort to manufacture and assemble various components.

[0004] When considering the energy consumption and wear during operation of the above-mentioned plain bearing assembly, it should be borne in mind that the carriage connected to the displaced element is merely an auxiliary means, especially if its mass represents a large proportion of the overall displaced mass, which also leads to a large proportion of the energy consumption for, for example, acceleration and deceleration, as well as to the surface pressure on the sliding surfaces, which is a decisive factor in wear.

[0005] Known plain bearing assemblies exhibit an unavoidable degree of wear of the sliding elements. If this is not noticed in time, metal-to-metal contact can lead to correspondingly more severe friction and damage to the carriage body. In this case, the carriage must be removed and the worn sliding elements and, under certain circumstances, the damaged metal carriage body must also be replaced. Depending on how frequently this occurs, the productivity of the corresponding process is impaired. A plain bearing assembly according to the generic term of claim 1 is known from US Pat. No. 5,623,999. Further prior art is known from US Pat. No. 5,623,999. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] German Utility Model No. 202018105755 [Patent Document 2] German Utility Model No. 202004016094 [Patent Document 3] US Patent Application Publication No. 2019 / 145642 Summary of the Invention

[0007] It is an object of the present invention to provide a plain bearing assembly and carriage which overcomes, at least to some extent, at least one disadvantage of conventional plain bearing assemblies, in particular by reducing energy consumption and wear and increasing productivity.

[0008] As one aspect of achieving the object inherent in the invention, the invention proposes a plain bearing assembly having the features set forth in claim 1.

[0009] The sliding bearing assembly according to the present invention comprises a rail and a carriage. The rail has a longitudinally elongated rail body, one cross section of which is provided with a cylindrical guide portion connected to the rail body via a neck portion of the rail. The cross section is a plane extending in the longitudinal direction and bounding the rail body in a transverse direction perpendicular to the longitudinal direction. The carriage has a carriage body through which extends a cylindrical passage intended to accommodate the guide portion. The carriage body has a longitudinal slot for accommodating the neck portion, the slot being connected to the passage and corresponding to the neck portion. The carriage body is preferably of rectangular parallelepiped configuration. In the intended state of the sliding bearing assembly, the neck consequently starts from the guide portion arranged in the passage and extends through the longitudinal slot to the rail body. The rail body is preferably shaped like a rectangular parallelepiped. The guide portion is preferably arranged at one edge of the rectangular parallelepiped rail body. By providing a passage and a longitudinal slot connected to the passage, the carriage can slide longitudinally along the rail, while the guide portion is disposed in the passage and slides along the passage on the carriage, and the neck portion is disposed in the longitudinal slot and is displaced relative to the carriage when positioned in the longitudinal slot. The inner surface of the passage is formed by a sliding element made of a sliding material, and by the inner surface of the passage, the carriage slides longitudinally against the guide portion in the intended operating state of the plain bearing assembly. According to the invention, the carriage body is manufactured together with the sliding element as an integral carriage part of plastic material. , small At least the inner surface of the passage is formed by tribopolymer, PreferablyAt least 80% by volume of the carriage part, i.e., at least 80% of the volume of the carriage part formed by the carriage body and the sliding elements, is provided by fiber reinforcement. The plastic material is preferably a polymer plastic material, and the plastic material is preferably a sliding material. The entire carriage is particularly preferably manufactured in one piece, in particular in a continuous manufacturing process of plastic material. The carriage as a whole is particularly preferably manufactured entirely from one and the same plastic material, in particular a tribopolymer. The carriage part can be divided into a carriage body region and a sliding element region. The sliding element region is a region of the carriage part that forms the inner surface of the passage and extends starting from the inner surface over a layer thickness of preferably 0.5 mm to 2 mm that protrudes from the inner surface into the carriage part. The carriage part preferably consists of a carriage body region and a sliding element region. Preferably, longitudinal grooves, i.e., longitudinal grooves, extending in the longitudinal direction, are formed on the inner surface of the passage, so that in the intended operating state the contact surface of the carriage or sliding element on the guide part is reduced, and an increase in friction, particularly due to dirt, can be prevented as much as possible. The sliding element area is preferably defined by the groove wall. The sliding element area is provided as an area in which sliding friction between the carriage and the guide part of the rail is expected, even in the event of wear, as intended.

[0010] The sliding material for manufacturing the carriage of the present invention should be understood to mean thermoplastic polymers such as polyethylene, polyoxymethylene (polyacetal), polypropylene, polyvinyl chloride, and polyethylene terephthalate, as well as thermosetting polymers such as epoxy resins, which have low coefficients of friction for static and sliding friction against metal and plastic surfaces. Friction and wear can be further reduced by adding a suitable lubricant, such as silicone oil or a fluorinated ethylene polymer, to the matrix polymer. Depending on their properties, these lubricants may be homogeneously mixed with or dissolved in the matrix polymer, or may be incorporated as a finely divided heterogeneous phase. In the latter case, it is advantageous for the particle size of the heterogeneous phase to be 0.01 to 10 μm.

[0011] Further reductions in friction and wear can be achieved by incorporating finely divided solid lubricants, alone or in combination with the above-mentioned lubricants, into the aforementioned sliding materials. Such materials are referred to herein as tribopolymers. Solids with a crystalline multilayer structure, such as graphite, molybdenum disulfide, molybdenum trioxide, tungsten disulfide, (hexagonal) α-boron nitride, and intercalation compounds of these substances, are suitable for this purpose. Inorganic compounds such as calcium fluoride and cerium fluoride are also contemplated. The particle size of the solid lubricant is advantageously between 0.01 and 50 μm. Fibers may be incorporated into the sliding material for reinforcement, particularly in the form of tribopolymers. Fiber reinforcement should be understood to mean the introduction of suitable fibers into a matrix polymer. These fibers consist of suitable materials with sufficient strength and sufficiently good bonding to the matrix polymer. Suitable fibers consist, for example, of glass, carbon, aramid, polyester, or polyamide. For processability, the length of these fibers is preferably between 0.1 and 10 mm. The fiber diameter is advantageously between 5 and 25 μm, and the fiber content of the material provided by the fiber reinforcement is advantageously between 5 and 50 volume percent.

[0012] The rail of the sliding bearing assembly according to the present invention has a cylindrical guide section connected to the rail body via a neck section. The length and thickness of this neck section are determined by the specific geometry of the periphery and the required stability. The neck section can generally be integrated into the rail body and marks the transition from the rail body to the guide section. In either case, the cylindrical passage must have a longitudinal slot through which the neck section can move longitudinally, and the neck section extending through the longitudinal slot connects the guide section to the rail body. The width of the longitudinal slot is determined by the thickness of the neck section. The thickness of the neck section is preferably dimensioned so that the longitudinal slot occupies less than one-quarter of the circumference of the passage.

[0013] Therefore, the carriage of the sliding bearing assembly according to the present invention no longer consists of two components that must be connected during installation, but rather a single carriage part that integrates the key features of the carriage body and the sliding element. These are, firstly, the inner surface of the passageway, for which low friction and high wear resistance are important, and, secondly, the carriage body, which must have sufficient strength and preferably low mass to be able to carry the mechanical elements fastened thereto during operation. The characterizing features of the main claim take this need into account. Therefore, in the carriage according to the present invention, the sliding element region is approximately 0.5 to 5 mm thick and is separated from the carriage body region adjacent to the inner surface of the passageway, corresponding to the reduced volume of the carriage around the sliding element region.

[0014] The rail of the plain bearing assembly according to the invention is preferably adapted to be fastened to a structure or support structure, in which holes for screws to be threaded may, for example, be provided for this purpose.

[0015] In a preferred embodiment, the entire carriage is made uniformly of sliding material, which may preferably be a tribopolymer also comprising fiber reinforcement, which simplifies the manufacturing process.

[0016] In one embodiment, the carriage body region has a higher fiber content than the sliding element region. Accordingly, the volume percentage of the fiber in the carriage component provided to reinforce the plastic material from which the carriage component is manufactured preferably varies throughout the volume of the carriage component. The fiber content per unit volume of the plastic material forming the inner surface is lower at the inner surface of the passage than in a carriage component region spaced at least 5 mm from the passage. Preferably, at the inner surface of the passage, no fiber is provided in the plastic material constituting the inner surface of the passage.

[0017] In one embodiment, the rail has a second guide portion attached to its other cross section. In this way, two different transport tasks can be performed by one plain bearing assembly, or a carriage with two matching tracks can be used, which provides higher load-bearing capacity and improved stability during displacement. The tracks can be configured or realized as described for one track. In particular, the entire carriage with two tracks can be configured as a single carriage part.

[0018] Continuous longitudinal grooves, or flutes, are advantageously provided on the inner surface of the passageway, thereby reducing sliding surfaces and potential friction.

[0019] The guide portion is preferably made integral with the rail body, although if deemed expedient it is also possible to manufacture the guide portion with only the neck and subsequently fasten it to the rail body.

[0020] The guide portion and optionally the rail body, preferably the entire rail, preferably consists of a metal or metal alloy, preferably aluminum or its alloys, titanium or its alloys, or magnesium or its alloys. The alloy components are preferably selected such that they increase strength and resistance to wear and optionally corrosion.

[0021] The present invention also provides a method for manufacturing a carriage for a plain bearing assembly according to the present invention. The carriage part is preferably manufactured using an injection molding method. In one embodiment, a suitable matrix polymer, i.e., base polymer, is mixed for this purpose with the desired additives, lubricants and / or solid lubricants, and in particular fibers, for example in an extruder, and then injected into an injection mold. After cooling, the carriage part can be removed from the mold as a molded part.

[0022] In order to obtain the most homogeneous dispersion of the additives within the matrix polymer, it is advantageous to use a premix of the additives prepared in the respective proportions of the matrix polymer for the final mixing, rather than using the pure additives.

[0023] In embodiments of the carriage according to the present invention that use different materials in the carriage body region and the sliding element region, a two-component injection molding method is preferably used accordingly. For this purpose, component A, which contains a matrix polymer, fibers, and optionally a lubricant, is first prepared for the carriage body region, and component B, which contains the corresponding matrix polymer and solid lubricant, is prepared for the sliding element region. These two components are then processed using a two-component injection molding method. Methods involving displaceable mold parts or co-injection can also be used for this purpose, as well as "insert injection molding," in which a part, e.g., a sliding element made of component B, is prefabricated and inserted into a mold for the entire carriage, which is then filled with component A. The key is that melting proceeds at the interface between the two components to form a unified carriage. For this purpose, compatible matrix polymers, preferably the same polymer, should be used for the two components.

[0024] Generally, in the method according to the present invention for manufacturing a carriage, the components are preferably processed in a multi-component injection molding process so that the solid lubricant and / or lubricant is concentrated on the inner surface of the passages and the reinforcing fibers in the carriage body are concentrated away from the inner surface of the passages. By using such a method, the properties of different carriage parts can be obtained in different areas of the carriage part directly during the manufacturing process.

[0025] The present invention further relates to a carriage for the plain bearing assembly according to the invention. The carriage is manufactured as a one-piece carriage part made of plastic material, which carriage part has integrated therein a carriage body and a sliding element made of a sliding material. A cylindrical passage corresponding to the cylindrical guide portion of a rail, which in addition to the cylindrical guide portion comprises a rail body connected to the guide portion via a neck portion similarly constituted by the rail, is provided in the carriage body for receiving the guide portion. The carriage body has a longitudinal slot for receiving the neck portion of the rail, which slot is connected to the passage and corresponds to the neck portion. The inner surface of the passage is formed by the sliding element, and by the inner surface of the passage, the carriage slides longitudinally against the guide portion in the intended operating state of the plain bearing assembly, i.e., during the intended use of the carriage. The carriage according to the present invention preferably has a width of 20 mm to 40 mm, in particular 20 mm to 30 mm, a length of 20 mm to 50 mm, in particular 25 mm to 35 mm, and a height of 10 mm to 25 mm, in particular 12 mm to 20 mm, and a weight of less than 20 g, in particular less than 15 g, in particular less than 12 g. The passage preferably has a diameter of 8 to 15 mm, in particular 8 to 12 mm, i.e., the distance between two diametrically opposed sliding contact surfaces formed by the inner surface of the carriage in contact with the guide portion during intended use. In particular, in combination with at least some of the above characteristics, the carriage simultaneously has a static load capacity of at least 20 N, in particular at least 25 N, in at least one load direction. The static load capacity is the load capacity that the carriage can bear in a load direction while the corresponding guide portion is received in the passage. The carriage, loaded with the corresponding load, can slide non-destructively longitudinally on the rail, while the guide portion of the rail is disposed in the passage and the guide portion of the rail is in sliding contact with the inner surface of the passage. The carriage transmits the load applied in the load direction and the resulting force against the guide portion of the rail.

[0026] The carriage according to the invention, the plain bearing assembly according to the invention and the method according to the invention may all have the features described in the various embodiments according to the invention relating to the various solutions according to the invention, which may further have the features described in connection with the generic embodiment.

[0027] Although not preferred, it is also possible to manufacture the carriage body and the sliding element separately and then rigidly connect them to one another, for example by adhesive bonding or welding.

[0028] The sliding bearing assembly according to the invention is distinguished by a lower displaced mass, which allows for lower energy input and / or an increased cycle rate for the production line. Furthermore, since only one part is replaced, the carriage can be easily replaced during maintenance, and the reduced wear allows for longer maintenance intervals. Since the carriage body here consists of sliding material, good emergency running properties are still obtained in the event of wear on the sliding element area, and unexpected breakdowns are avoided. It is also possible to dispense with the use of additional lubricants. The carriage is here completely metal-free and can be effectively reused. Due to the reduced mass, noise generation during operation is reduced, and there is no contamination of the surroundings due to worn metal. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a schematic diagram of an embodiment of a carriage according to the present invention. [Figure 2] FIG. 2 is a perspective schematic view of one embodiment of a sliding bearing assembly according to the present invention. [Figure 3] FIG. 3 is a schematic side view of the embodiment shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0030] The invention will now be explained in more detail with reference to exemplary embodiments on the basis of the drawings.

[0031] FIG. 1 shows a perspective view of one embodiment of a carriage 20 according to the present invention. It is clear from FIG. 1 that the carriage 20 has a rectangular parallelepiped-shaped carriage body through which a passage 22 extends. The passage 22 is configured in the form of a cylinder, the axis of which extends in the longitudinal direction. Furthermore, the carriage body has a longitudinal slot 26 connected to the passage 22. FIG. 3 in particular shows that, in the intended state of the plain bearing assembly 1 according to the present invention, the neck portion 13 of the rail passes through the longitudinal slot 26, and is connected to the guide portion 11 arranged in the passage 22 on the one hand, and to the rail body 10, which is configured to be attached to a component on the other hand. The axis of the cylinder of the passage 22 extends substantially parallel to four of the six rectangular faces of the cuboid that constitutes the carriage body. The carriage 20 has a mounting surface facing upward in FIG. 1 and through which two fastening channels 27 extend, so that a working device can be fastened to the mounting surface of the carriage by fastening means, e.g., screws, which are threaded through the fastening channels 27. 1 further shows that the carriage as a whole takes the form of a one-piece carriage part that integrally forms a sliding element on the inner surface of the track. A longitudinal groove 23 is provided on the inner surface of the track. The depth of the groove, which extends radially relative to the cylindrical axis of the track 22, defines the sliding element area, i.e., the area in which frictional contact is provided between the carriage and the guide portion of the rail arranged in the track 22, even in the presence of wear during the intended use of the carriage 20.

[0032] Figure 2 shows a perspective top view of a plain bearing assembly 1 according to the present invention. One can see the rail body 10 of the rail with the guide portion 11 mounted thereon. A carriage 20 slides slidably on the guide portion, and a cylindrical passage 22 receives the guide portion 11 of the rail. A longitudinal groove 23 is recessed into the inner surface of the passage 22 to reduce the contact area and friction.

[0033] FIG. 3 shows a side view of a slide rail assembly. Dimension lines refer to the exemplary embodiment below. Again, the rail can be seen, with a rail body 10 and a guide portion 11 interconnected by a neck portion 13. The neck portion 13 extends through a longitudinal slot 26 within a cylindrical passageway 22, occupying less than one-quarter of the circumference of the passageway. A sliding element region 25 is shown here as part of the carriage 20, occupying approximately 0.5-5 mm of the carriage volume surrounding the passageway 22. The remainder of the carriage forms a carriage body region 24. [Explanation of symbols]

[0034] 1. Plain bearing assembly 10 Rail body 11 Guide part 12 screw holes 13 Neck part 20 carriages 22 Cylindrical Passage 23 Longitudinal groove 24 Carriage body area 25 Sliding element area 26 Longitudinal Slots 27 Concluding Channel

Claims

1. A sliding bearing assembly (1) comprising a rail and a carriage (20), wherein the rail has a longitudinally elongated rail body (10) and in one cross section thereof is provided with a cylindrical guide portion (11) connected to the rail body (10) via a neck portion of the rail, and the carriage (20) has a carriage body with a sliding element region (25) provided with a cylindrical passage (22) corresponding to the guide portion (11) for receiving the guide portion (11), and the carriage body is a carriage body region (24) having a rectangular parallelepiped shape, the carriage body having a longitudinal slot (26) for receiving the neck portion (13), the slot (26) being connected to the passage (22) and corresponding to the neck portion (13), the inner surface of the passage (22) being formed by the sliding element region (25) made of a sliding material, the carriage (20) being in sliding contact with the guide portion (11) in the longitudinal direction by the inner surface of the passage when the plain bearing assembly is in an operating state; The entire carriage (20), including the rectangular parallelepiped carriage body region (24) and the sliding element region (25), is a one-piece carriage part made of plastic material and manufactured integrally from a tribopolymer, and the inner surface of the passage (22) in the sliding element region (25) is formed by the tribopolymer.

2. A sliding bearing assembly (1) as described in claim 1, wherein at least 80% by volume of the carriage parts are provided with fiber reinforcement.

3. 2. The plain bearing assembly (1) according to claim 1, wherein the carriage body region (24) has a higher fiber content than the sliding element region (25).

4. 2. The sliding bearing assembly (1) according to claim 1, wherein cylindrical guide portions (11) are provided on both sides of the rail body (10), and the assembly comprises two carriages (20) each having one passage (22), or one carriage (20) having two passages (22), and the guide portions (11) of the rail body (10) are received in the passages (22).

5. 2. The plain bearing assembly (1) according to claim 1, wherein the inner surface of the passage (22) is provided with longitudinal grooves.

6. 2. The plain bearing assembly (1) according to claim 1, wherein the cylindrical passage (22) surrounds the guide portion (11) over at least three-quarters of its circumference.

7. 2. The plain bearing assembly (1) according to claim 1, wherein the guide portion (11), in particular the entire rail, is manufactured from a metal or a metal alloy, in particular from aluminum or an alloy thereof, titanium or an alloy thereof, magnesium or an alloy thereof or stainless steel.

8. A carriage (20) for a plain bearing assembly (1) according to any one of claims 1 to 7, comprising: The carriage (20) has a carriage body comprising a carriage body region (24) and a sliding element region (25), and is manufactured as an integral carriage part from a plastic material of a tribopolymer, the carriage body region (24) and the sliding element region (25) being integrally manufactured from the tribopolymer, and a cylindrical passage (22) is provided in the carriage for receiving a cylindrical guide portion (11) of the rail, the cylindrical guide portion (11) further comprising a rail body (10) connected to the guide portion (11) via a neck portion (13). a carriage (20) provided in the sliding element region (25) of a carriage body, the carriage body further having a longitudinal slot (26) for receiving the neck portion (13), the slot (26) being connected to the cylindrical passage (22) and corresponding to the neck portion (13), the inner surface of the cylindrical passage (22) being formed from the tribopolymer, the inner surface of the cylindrical passage allowing the carriage (20) to slide in contact with the guide portion (11) in the longitudinal direction when the plain bearing assembly (1) is in an operating state.

9. 9. The carriage (20) according to claim 8, wherein the carriage (20) has a width of 20 mm to 40 mm, a length of 20 mm to 50 mm and a height of 10 mm to 25 mm, a weight of less than 20 g, in particular less than 15 g, and a static load capacity of at least 20 N in at least one load direction.

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