Method for remanufacturing an internally splined component

Abstract

A remanufactured inner spline component (400) includes an interior surface (420) defining a cylindrical bore (410) and a remanufactured inner geometry (430) on the interior surface (420). The inner geometry (430) has a maximum diameter (470) and a minimum diameter (460). The remanufactured inner geometry (430) is produced by removing (620) a worn inner geometry (430) to a pre-clad diameter (480), cladding (630) the interior surface (420) in a plurality of layers by laser cladding to produce a cladded surface (490), and machining (640) the cladded surface (490) to produce the remanufactured inner geometry (430).

Description

Technical Field

[0001] This disclosure generally relates to splined components, and more specifically to methods for remanufacturing internal splined components. Background Technology

[0002] A bulldozer is an electric machine used for digging and loading soil or gravel, as well as for mining. Unlike more common excavators, the bulldozer's bucket is moved by a series of cables and winches rather than hydraulic devices. To function, the upper section of the bulldozer must rotate relative to the ground to remove the excavated material from the digging site. This rotation requires a fairly large rotary drive, which consists of multiple splined components that transmit energy from the motor to the rotating parts.

[0003] A splined connection is used to transmit torque from a shaft to a gear hub or other rotating components. The external gear teeth on the shaft mesh with the same number of internal teeth in the hub. Because multiple teeth mesh simultaneously, they can transmit a larger torque.

[0004] Splined connections are used in a variety of engines, motors, and other systems with rotating moving parts. In many such systems, these parts suffer considerable wear, but replacement parts are quite expensive. In many applications, the bore of an internal splined component is much longer than its diameter. In these cases, damage or wear to the internal geometry can be difficult to repair using conventional methods.

[0005] Processes exist for repairing external spline components. For example, the process disclosed in U.S. Patent Application Publication No. 2006 / 0228219A1 by Finton et al. teaches a method for repairing external splines in which additional material is welded to the surface of each tooth of the external spline and then machined into the correct shape. However, this process cannot be applied to internal splines due to limited space and the risk of overheating of the internal surfaces. Therefore, a method for remanufacturing internal spline components remains needed. Summary of the Invention

[0006] According to one aspect of this disclosure, a remanufactured internal spline component is disclosed. The remanufactured internal spline component includes an internal surface defining a cylindrical bore and a remanufactured internal geometry on the internal surface. The internal geometry has a maximum diameter and a minimum diameter. The remanufactured internal geometry is produced by the following steps: removing the worn internal geometry to a pre-cladding diameter, cladding the internal surface in multiple layers by laser cladding to create a cladding surface, and machining the cladding surface to produce the remanufactured internal geometry.

[0007] According to another aspect of this disclosure, a method for remanufacturing an internal spline component is disclosed. The method includes: providing an internal spline component having an internal surface defining a cylindrical bore and worn internal geometry on the internal surface; removing the worn internal geometry to a pre-cladding diameter; cladding the internal surface in multiple layers by laser cladding to produce a clad surface; and machining the clad surface to produce the remanufactured internal geometry.

[0008] According to another aspect of this disclosure, a spline connection is disclosed. The spline connection includes an external spline component and a remanufactured internal spline component. The remanufactured internal spline component includes an internal surface defining a cylindrical bore and a remanufactured internal geometry on the internal surface. The internal geometry has a maximum diameter and a minimum diameter. The remanufactured internal geometry is produced by the following steps: removing the worn internal geometry to a pre-cladding diameter, cladding the internal surface in multiple layers by laser cladding to produce a clad surface, and machining the clad surface to produce the remanufactured internal geometry.

[0009] These and other aspects and features of this disclosure will be more readily understood after reading the following detailed description in conjunction with the accompanying drawings. Attached Figure Description

[0010] Figure 1 This is a perspective view of an electric rope bulldozer according to one aspect of this disclosure.

[0011] Figure 2 This is based on one aspect of the disclosure. Figure 1 A perspective view of the rotary drive of the electric rope bulldozer shown.

[0012] Figure 3 This is based on one aspect of the disclosure. Figure 2 The cross-section of the planetary gearbox of the rotary drive is shown.

[0013] Figure 4 This is a perspective view of a spline connection according to one aspect of this disclosure.

[0014] Figure 5 This is based on one aspect of the disclosure. Figure 3 The perspective view and cross-section of the planet carrier gear of the planetary gearbox are shown.

[0015] Figure 6 This is based on one aspect of the disclosure. Figure 3 The diagram shows a perspective view and cross-section of the output gear of the planetary gearbox.

[0016] Figure 7 This is a cross-sectional view of an internal spline component according to one aspect of this disclosure.

[0017] Figure 8This is a cross-sectional view of an internal spline component according to one aspect of this disclosure.

[0018] Figure 9 This is a cross-sectional view of an internal spline component according to one aspect of this disclosure.

[0019] Figure 10 This is a flowchart of a method for remanufacturing an internal spline component according to one aspect of this disclosure. Detailed Implementation

[0020] Now refer to the attached diagram, and specifically refer to... Figure 1 The image depicts an electric rope bulldozer, referred to as reference numeral 100. The electric rope bulldozer 100 is an electric machine used for digging and loading soil or gravel, and for mining. The bulldozer 100 includes a frame 110 having an upper section 112 and a lower section 114, a track system 120 supporting the frame 110, an engine 130, an operator's cab 140, and a digging arm 150 equipped with a bucket 160 mounted on the frame 110.

[0021] The upper section 112 and the lower section 114 of frame 110 are configured to rotate relative to each other. Rotation is controlled by a rotary drive 200, wherein the lower half... Figure 2 As shown in the diagram (the upper half is substantially similar and rotated vertically by 180 degrees). The rotary drive 200 includes two planetary gearboxes 210, each driven by a motor 220 and located on each segment of the frame 110. These gearboxes 210 drive a rotary rack (not shown) and rotate the upper segment 114.

[0022] like Figure 3 As shown in cross-section, the planetary gearbox 210 includes components such as a planet carrier gear 230 and an output gear 240, which facilitate the transmission of energy from the motor 220 to a shaft (not shown) that drives a rotary rack (not shown). Both the planet carrier 230 and the output gear 240 include internal spline components and serve as half of a spline connection.

[0023] Figure 4An exemplary spline connection 300 is depicted. The spline connection 300 includes two parts: an outer spline component 310 and an inner spline component 400. The outer spline component 310 may be part of a cylindrical shaft 320 and has an outer geometry 330 surrounding at least some portions of an outer surface 340. The inner spline component 400 has an inner bore 410 configured to mate with the outer spline component 310 therein. The inner bore 410 is generally cylindrical and defined by an inner surface 420. At least some portions of the inner surface 420 have an inner geometry 430. The inner geometry 430 is configured to mate with the outer geometry 330 of the corresponding outer spline component 310. Specific embodiments of the planet carrier 230 and the output gear 240 of the planetary gearbox 210 are described in [details omitted]. Figure 5 and Figure 6 Described in the text.

[0024] Figure 7 A stylized cross-section of the inner spline component 400 is shown. The inner geometry 430 may include a plurality of teeth 440 and slots 450 extending parallel to the longitudinal axis of the bore 410. The teeth 440 and slots 450 are configured to mate with corresponding teeth and slots on the outer spline component 330. The teeth 440 extend radially inward toward the center of the bore 410. The teeth 440 may be of any shape known in the art, including straight teeth and involute teeth. The slots 450 extend radially outward away from the center of the bore 410. A minimum diameter 460 may be measured from the center point of the tooth 440, and a maximum diameter 470 may be measured from the outermost point of the slot 450. In other embodiments, the teeth 440 and slots 450 may spiral around the inner surface 420, including flat sections for alignment or other geometries known in the art.

[0025] In a specific embodiment of the output gear 240, the bore 410 can be 16 inches deep and have a maximum diameter of 9 inches. The internal geometry can extend 8 inches. The tooth 440 can have a total height of 3 / 8 inch, resulting in a minimum diameter 460 of 8.25 inches.

[0026] During use, the internal spline component 400 is subjected to considerable stress. This can lead to wear and damage to the inner geometry 430, particularly the edges of the teeth 440. When the wear becomes severe enough, component 400 ceases to function and may cause gearbox 210 to fail or malfunction. While methods for repairing the external spline component 310 are known, damage or wear to the inner geometry 430 can be difficult to repair using conventional methods. Part of the reason for this difficulty is that the bore 410 of the internal spline component 400 is typically much longer than its diameter, making access challenging. Furthermore, repairing the internal spline component 400 requires the addition of additional material. Most methods of adding material, such as welding, require a significant amount of heat, which can overheat the internal surface 420. In a component 400 with deep bores 410, it may be difficult to dissipate heat at the required rate.

[0027] However, the internal spline component 400 can be repaired using a laser cladding remanufacturing process. This process comprises three main aspects: removal of the worn internal geometry 430, cladding, and machining remanufacturing of the internal geometry 430.

[0028] Removing the worn inner geometry 430 requires machining the internal surface 420 until the worn inner geometry 430 disappears and a generally smooth surface suitable for subsequent laser cladding is produced. Any method known in the art can be used for this step, including but not limited to broaching, cutting, and milling. The process should remove at least all material down to the maximum diameter 470 of the inner geometry 430. Preferably, the internal surface 420 should be removed to a pre-cladding diameter 480 larger than the maximum diameter 470 of the inner geometry 430, such as... Figure 8 As shown. Figure 8 The internal geometry is also depicted as dashed lines. This allows for the removal of any material that may contain hidden microcracks and fatigue. Furthermore, removal to a depth below the internal geometry allows any stress generated at the interface between the original material and the cladding material to be buried within the component and not in areas subjected to additional stress. In some cases, typical instances of worn components can be analyzed to determine the typical depth of potentially damaging material and accordingly set the pre-cladding diameter to 480.

[0029] In a specific embodiment of the output gear spline component 240, the entire tooth 440 passing through the bottom of the groove 450 can be removed. The pre-cladding diameter 480 can be 3 mm larger than the maximum diameter 470 of the inner geometry 430.

[0030] Once the substrate is prepared, new material is accumulated on the inner surface 420 by laser cladding to create a cladding surface 490 with a post-cladding diameter of 500. The cladding surface 490 typically has no internal geometry. Laser cladding is a method of adding material to a surface by melting a raw material with a laser and bonding the molten material to the surface. The raw material can be in the form of powder or wire. Laser cladding is performed by a cladding head (not shown) that guides the laser and the raw material to meet at the cladding surface 490. In the case of deep holes such as planetary carriers 230 and output gears 240, the hole 410 needs to be configured with a cladding head that functions within a confined space. In some embodiments, the cladding head can be configured to deflect the laser at an angle.

[0031] The material selected for cladding should be chosen to bond well with the internal surface 420 of the internal spline component 400 while maintaining the same material properties. Specifically, the material should have the same hardness so that it does not wear out too quickly and cause excessive damage to the external spline component 310. Furthermore, the material must have similar stress, wear, and fatigue modes to prevent the formation of weak points at the boundaries. Finally, the material's porosity must be low to ensure complete bonding with the internal surface 430.

[0032] The cladding material can be added in multiple layers until a post-cladding diameter of 500 is reached. The post-cladding diameter of 500 must be greater than the minimum diameter of the inner geometry 430 (460) to allow for machining, such as... Figure 9 As shown. Figure 9 The internal geometry is also depicted as dashed lines. The thickness of each layer can be 1 to 2 mm. In some embodiments, 6 to 7 layers may be required, but any number of layers can be used as needed. Using multiple layers can help avoid overheating of the internal surface 420 and produce a more consistent surface for subsequent steps.

[0033] Finally, the cladding surface 490 is machined to produce the remanufactured internal geometry 430. This step can be performed by any method suitable for this purpose, including but not limited to broaching, cutting, and milling.

[0034] Industrial applicability

[0035] Splined connections are used in a variety of engines, motors, and other systems with rotating moving parts. In many such systems, these parts suffer considerable wear, but replacement parts are quite expensive. Accordingly, the method for remanufacturing internal splines according to this disclosure can be used for components in many applications, including mining and construction equipment, agricultural machinery, vehicles, and any system where spline connections in gearboxes undergo considerable wear.

[0036] Remanufacturing method 600 includes four steps, such as Figure 10 As shown. First, as shown in box 610, an internal spline component 400 with a worn internal geometry 430 on the inner surface 420 of a cylindrical bore 420 is provided. Next, the worn internal geometry 430 must be removed (box 620). Removing the worn internal geometry 430 requires machining the inner surface 420 to provide a suitable surface for laser cladding. This process should remove at least all material down to the maximum diameter 470 of the internal geometry 430. Preferably, the inner surface 420 should be machined to a pre-cladding diameter 480, which is larger than the maximum diameter 470 of the internal geometry 430. This allows for the removal of material that may contain hidden microcracks and fatigue. Any method known in the art can be used for this step.

[0037] Next, as shown in box 630, cladding material can be added in multiple layers to the inner surface 420 to create a clad surface 490 until a post-cladding diameter 500 is reached. The post-cladding diameter 500 must be larger than the minimum diameter 460 of the inner geometry 430 to allow for machining. The thickness of each layer can be 1 to 2 mm. In some embodiments, 6 to 7 layers may be required, but any number of layers can be used as needed. Using multiple layers can help avoid overheating of the inner surface 410 and produce a more consistent clad surface 490 for subsequent steps.

[0038] Finally, the remanufactured inner geometry 430 of the inner spline component 400 is produced by any suitable method of machining the cladding surface 490, as shown in box 640.

[0039] While the foregoing text has described many different embodiments in detail, it should be understood that the legal scope of protection is defined by the wording of the claims set forth at the end of this patent. The detailed descriptions should be interpreted as exemplary only and do not describe every possible embodiment, as describing every possible embodiment would be impractical, if not impossible. Many alternative embodiments can be implemented using current technology or technology developed after the filing date of this patent, and these alternative embodiments still fall within the scope of the claims that define the scope of protection.

Claims

1. A remanufactured internal spline component (400), comprising: The inner surface (420) of the cylindrical hole (410) is defined. and A remanufactured inner geometry (430) on the inner surface (420), the remanufactured inner geometry (430) having a maximum diameter (470) and a minimum diameter (460), the remanufactured inner geometry (430) being produced by the following steps: The worn inner geometry (430) is removed down to the pre-cladding diameter (480), which is greater than the maximum diameter (470) of the inner geometry (430). The inner surface (420) is clad in multiple layers by laser cladding to create a clad surface (490), the clad surface (490) having a clad diameter (500) smaller than the minimum diameter (460) of the inner geometry (430), and The cladding surface (490) is machined to produce the remanufactured inner geometry (430).

2. The internal spline component (400) according to claim 1, wherein the internal geometry (430) comprises a plurality of teeth (440) and grooves (450).

3. The internal spline component (400) according to claim 1, wherein the length of the cylindrical hole (410) is greater than its diameter.

4. The internal spline component (400) according to claim 1, wherein the internal spline component (400) is a planetary gear.

5. The internal spline component (400) according to claim 1, wherein the internal spline component (400) is an output gear.

6. A method (600) for remanufacturing an internal spline component (400), the method comprising: Provided (610) an internal spline component (400) having an internal surface (420) defining a cylindrical bore (410) and an internal geometry (430) worn on the internal surface (420), wherein the internal geometry (430) has a maximum diameter (470) and a minimum diameter (460). The worn inner geometry (430) is removed (620) to a pre-cladding diameter (480), which is greater than the maximum diameter (470) of the inner geometry (430). The inner surface (420) is clad in multiple layers (630) by laser cladding to produce a clad surface (490), the clad surface (490) having a clad diameter (500) smaller than the minimum diameter (460) of the inner geometry (430), and The cladding surface (490) is machined (640) to produce a remanufactured internal geometry (430).

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