EP4649243A1

EP4649243A1 - Slewing bearing production method

Info

Publication number: EP4649243A1
Application number: EP24843622.2A
Authority: EP
Inventors: Mehmet Serkan ERTEN
Original assignee: Alp Havacilik Sanayi Ve Ticaret AS
Current assignee: Alp Havacilik Sanayi Ve Ticaret AS
Priority date: 2023-07-18
Filing date: 2024-07-16
Publication date: 2025-11-19
Also published as: GB2642119A; EP4649243A4

Abstract

The invention relates to a slewing bearing production method used in rotating systems such as cranes, wind turbines, and excavators, in rotating mechanisms in different industries such as mining machines, tunnel boring machines, and marine cranes, and more specifically in large satellite antennas of radar systems and turrets of weapon systems, enabling the production of a slewing bearing with a steel part (20) bonded to the aluminum inner ring (10a) and aluminum outer ring (10b) via a metal-to-metal bonding process as a single piece.

Description

DESCRIPTION Slewing Bearing Production Method Technical Field The invention relates to bearings known as slewing bearings, which are used in various rotating systems such as cranes, wind turbines, excavators, mining machines, tunnel boring machines, marine cranes, and more specifically, in radar systems' large satellite antennas and turret systems of weapon systems. In particular, the invention concerns a production method for slewing bearings, which enables the production of these bearings as a single piece by bonding high-strength metals (such as steel) to aluminum rings via a metal-to-metal bonding process instead of manufacturing them in a segmented structure with a steel wire bearing system. State of the Art Slewing bearings are generally produced in a wide variety of sizes and geometries, operating at low speeds with high load capacity. These bearings are resistant to forces coming from different directions and are equipped with steel wire bearing systems. These bearing elements are manufactured externally and mounted onto the bearings. In current systems, aluminum ring gear body elements are frequently used. However, due to the lower mechanical properties and hardness of aluminum compared to steel, desired surface hardening processes cannot be applied to this material, leading to deformation problems in the aluminum body parts used. The use of high-strength materials like steel as bearing elements is intended to address this issue. The steps of the known method are as follows: Steel wire is brought to the appropriate geometry through a cold drawing method. During this process, the gaps at the junction points of the parts can lead to a loss of system precision over time and rapid deformation of the bearing rolling elements. The wire is bent to the appropriate diameter for the aluminum ring. At this stage, the wire can twist and turn around itself during the bending process. Correcting this deformation is generally difficult. The wire undergoes a heat treatment to achieve the appropriate hardness. At this stage, high temperatures followed by rapid cooling can cause distortions, and correcting these distortions is generally difficult. These known methods can negatively affect the long- term performance of the bearings. Current solutions are insufficient to address the production and performance issues. In slewing bearings, the process of applying a steel wire bearing system to the aluminum part is as follows: ^ Obtaining the appropriate geometry of the wires through cold drawing method. Cold shaping of steel wire to the appropriate diameter for the aluminum alloy ring groove. At this step, the parts cannot be pre-hardened to facilitate the bending process. Additionally, the wire can twist around itself during the bending process, and perfectly correcting this condition is not possible. The steel wire material is hardened through heat treatment to achieve the appropriate hardness. At this step, reaching the austenitizing temperature for the hardening process and rapid cooling can cause distortions. Correcting these distortions is necessary, but it is a challenging process to achieve successfully. As a result of these processes, the system's precision decreases after a certain period due to the gaps at the junction points of the parts. Additionally, due to these gaps, the bearing rolling elements deform more quickly. After the application of a steel wire bearing system on the aluminum part, the desired performance values cannot be maintained for a long time. In the state of the art, there is a need for a method to eliminate the production and performance problems of slewing bearings manufactured in a segmented structure with a steel wire bearing system. In the literature, an example of the state of the art is document CN104595364. This document describes a three-row roller slewing bearing with a stepped joint between an upper ring and a lower ring. Here, an upper roller path, a middle roller path, and a lower roller path are arranged on the upper plane, the middle part, and the lower plane, respectively. The stepped joint between the upper ring and the lower ring is in the vertical plane and the lower plane. The upper roller path and the lower roller path are in the form of annular circular tubes, and the middle roller path is also in the form of an annular square tube. The diameters or side lengths of the roller paths are equal; the annular circular tube-shaped roller paths are filled with spherical rollers internally; the square tube-shaped roller paths are filled with short cylindrical rollers internally, and the diameters of the short cylindrical rollers are slightly larger than the side lengths of the square tube-shaped roller paths. The roller paths can also be filled alternately with spherical rollers and cylindrical rollers; each pair of adjacent or close short cylindrical rollers intersects each other vertically; the diameters of the spherical rollers and the cylindrical rollers are equal. This document does not mention a metal-to-metal bonding method. Another example of the state of the art is document CN210919840. This document describes a double-row sealed slewing bearing consisting of an outer ring, a rolling body, a sealing ring, and an inner ring of the slewing bearing, where the middle of the outer ring and the middle of the inner ring form a rolling path. The rolling body is arranged in the rolling path, and an upper T-shaped groove is formed at the edge of the upper end face of the outer ring, while a first circular sealing groove is formed at the opposite position of the outer circumference of the inner ring. A T-shaped lower groove is formed at the edge of the lower end face of the inner ring, and a second circular sealing groove is formed at the opposite position of the inner hole face of the outer ring. The outer ring and the inner ring are sealed with a sealing ring, one end of the sealing ring is fixed in the upper T-shaped groove or the lower T-shaped groove, and the other end of the sealing ring is fixed in the first circular sealing groove. This double-row sealed slewing bearing effectively prevents foreign substances such as water and dust from entering the rolling path. This document does not mention a steel- aluminum bonding method. Another example of the state of the art is document CN208185242. This document describes a light-duty aluminum rotary bearing. The outer strip, inner circle, and rolling element are included; the outer strip includes an aluminum alloy outer strip base element and presents an outer roller path groove on the connection ring on the aluminum base element. The alloy outer strip, inner circle includes an aluminum alloy inner circle base element and presents an inner roller path groove on the anchor ring outside the aluminum alloy inner circle base element, which has two stainless steel wires to insert into the outer roller path groove and the inner roller path groove. The four stainless steel wires' longitudinal section forms a square, the outer roller path groove and the inner roller path groove form a rolling path, and the rolling element is mounted in contact with the stainless steel wire channel. The relevant application states that the aluminum alloy fully adapts to the rotary bearing's outer strip, offering a lightweight advantage and adopting a structure with embedded stainless steel wire, ensuring the rotary bearing's lifespan and allowing the stainless steel wire to be replaced after the subsequent stage. However, this document does not mention a steel-aluminum bonding method. In conclusion, the existence of the above problems and the inadequacy of existing solutions have necessitated an improvement in the relevant technical field. Objective of the Invention The present invention relates to a method for producing slewing bearings that eliminates the disadvantages mentioned above and brings new advantages to the relevant technical field. The main objective of the invention is to present a slewing bearing produced as a single piece by bonding a steel part to aluminum rings via a metal-to-metal bonding process instead of manufacturing it in a segmented structure with a steel wire bearing system. The objective of the invention is to present a high-performance and durable slewing bearing by simplifying the assembly geometry and bonding the active working surfaces with a metal-to-metal bonding process. Another objective of the invention is to present a slewing bearing suitable for mass production by eliminating geometric and production difficulties. Another objective of the invention is to present a slewing bearing that operates continuously and without surface defects by eliminating gaps. To achieve all the objectives mentioned above and that may emerge from the detailed description, the invention provides a slewing bearing production method used in rotating systems such as cranes, wind turbines, excavators, mining machines, tunnel boring machines, marine cranes, and more specifically, in radar systems' large satellite antennas and turret systems of weapon systems, including the following steps: a) Machining the aluminum inner ring and aluminum outer ring to pre-dimensions, and machining the steel part to pre-dimensions for bonding operation, b) Bonding the steel part between the aluminum inner ring and aluminum outer ring, c) Machining the aluminum inner ring, aluminum outer ring, and steel part together in a processing machine to the final form, d) Assembling the final form of the aluminum inner ring and aluminum outer ring with other sub-parts to produce the final product. The structural and characteristic features of the invention and all its advantages will be understood more clearly through the detailed description given below with references to the figures. Therefore, the evaluation should be made considering these figures and the detailed description. Figures to Aid in Understanding the Invention Figure 1: Sectional view of the slewing bearing subject to the invention. Figure 2a: View of the aluminum inner ring of the slewing bearing subject to the invention. Figure 2b: View of the aluminum outer ring of the slewing bearing subject to the invention. Figure 3: View of the steel part of the slewing bearing subject to the invention. Figure 4a: View of the aluminum inner ring and steel part of the slewing bearing subject to the invention. Figure 4b: View of the aluminum outer ring and steel part of the slewing bearing subject to the invention. Figure 5a: View of the aluminum inner ring and steel part of the slewing bearing subject to the invention. Figure 5b: View of the aluminum outer ring of the slewing bearing subject to the invention. Figure 6: General view of the slewing bearing subject to the invention. Parça Referanslarının Açıklanması 10a.Aluminum inner ring 10b.Aluminum outer ring 20. Steel part 30. Adhesive Detailed Description of the Invention In this detailed description, the slewing bearing production method subject to the invention is explained only for better understanding and should not be considered as limiting. The invention relates to a slewing bearing production method (Figure 1) used in rotating systems such as cranes, wind turbines, excavators, mining machines, tunnel boring machines, marine cranes, and more specifically, in radar systems' large satellite antennas and turret systems of weapon systems. The slewing bearing production method subject to the invention includes the following steps: Machining the aluminum inner ring (10a) and aluminum outer ring (10b) to pre- dimensions (Figure 2a, Figure 2b), and bringing the steel part (20) to be bonded (Figure 3) to pre-dimensions, The aluminum inner ring (10a) and aluminum outer ring (10b), which have been pre- sized, are taken for preparation for bonding and surface preparation. The surface preparation processes are as follows in sequence: ^ The layer formed on the surface of the aluminum inner ring (10a) and aluminum outer ring (10b) as a result of the anodizing process is very thin and provides corrosion resistance. ^ Bonding prime process. After the anodizing and prime processes, the surfaces of the aluminum inner ring (10a) and aluminum outer ring (10b) are cleaned. The pre-sizing of the steel part (20), which is to be bonded to the aluminum inner ring (10a) and aluminum outer ring (10b) and shown in Figure 3, is provided by traditional methods. The surface preparation process of the stainless steel part (20) with rough dimensions obtained is performed. Before the bonding processes, the surface preparation processes are completed, and film adhesive (30) is applied to the aluminum inner ring (10a), aluminum outer ring (10b), and steel part (20). As shown in Figure 4a, the steel part (20) is attached to the aluminum inner ring (10a), and then the aluminum outer ring (10b) is placed outside the aluminum inner ring (10a) as shown in Figure 4b and assembled. The curing process is performed on the aluminum inner ring (10a) and aluminum outer ring (10b) with the steel part (20) in between, and the aluminum inner ring (10a), aluminum outer ring (10b), and steel part (20) brought to their final dimensions together (Figures 5a and 5b). The final form of the aluminum inner ring (10a) and aluminum outer ring (10b) is combined with other sub-parts to produce the final product.

Claims

CLAIMS 1) A method for producing a slewing bearing used in heavy rotating systems such as cranes, wind turbines, and excavators, in industrial rotating mechanisms such as mining machines, tunnel boring machines, and marine cranes, and more specifically in large satellite antennas of radar systems and turrets of weapon systems, characterized by; a) Machining the aluminum inner ring (10a) and aluminum outer ring (10b) to pre- dimensions, and machining the steel part to pre-dimensions for bonding operation, b) Bonding the steel part (20) between the aluminum inner ring (10a) and aluminum outer ring (10b), c) Machining the aluminum inner ring (10a), aluminum outer ring (10b), and steel part (20) together in a processing machine to the final form, d) Assembling the final form of the aluminum inner ring (10a) and aluminum outer ring (10b) with other sub-parts to produce the final product, comprising the process steps. 2) The method for producing a slewing bearing according to claim 1, characterized by; including surface preparation processes applied in the mentioned step (b). 3) The method for producing a slewing bearing according to claim 1, characterized by; not having gaps formed by applying a special method in the mentioned step (b).