Method and equipment for repairing external thread of shaft on site

Abstract

The invention relates to a method and equipment for repairing external threads of a shaft on site, the equipment used in the method comprises a three-jaw chuck (1), a male end thread sample plate sleeve (2) and a female end thread sample plate sleeve (3) which are coaxially arranged, one end of the male end thread sample plate sleeve (2) is fixedly connected with the three-jaw chuck (1), and the other end of the male end thread sample plate sleeve (2) is in threaded connection with the female end thread sample plate sleeve (3). A turning tool is fixedly installed at the end, away from the male end thread sample plate sleeve, of the female end thread sample plate sleeve (3). The turning tool is fixedly arranged on the female end thread sample plate sleeve, the turning tool is driven to rotate and axially move through rotation and axial movement of the female end thread sample plate sleeve, and the machining track of an external thread to be repaired is converted into a connecting thread between the female end thread sample plate sleeve and the male end thread sample plate sleeve; therefore, the turning tool moves along the spiral groove of the to-be-repaired external thread, a shaft where the to-be-repaired external thread is located does not need to be disassembled, and the operation efficiency of repairing the shaft is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of mechanical repair technology, and in particular to the repair of shaft components, specifically a method and equipment for on-site repair of external threads on shafts. Background Technology

[0002] Shafts are a very important component in mechanical equipment, especially in transmission technology, where they are an indispensable part. By installing various parts on the shaft, the purpose and requirements of use are achieved.

[0003] The main methods of mounting parts on a shaft include interference fit, welding, key connection and threaded connection. For parts connected to a shaft by thread, the threads on the shaft will be damaged after a long period of use, such as stripping or wear, causing the threads to fail to function properly.

[0004] Currently, when external threads on shafts need repair at the repair site, thinner shafts are typically processed using dies. However, due to the wide variety of thread specifications, it's impossible to have a suitable die for every thread, and for threads with larger outer diameters, dies cannot be used. Therefore, in most cases, the shaft needs to be completely removed and transported to a machining workshop for thread cutting on a lathe to repair the threads before being returned to the repair site for reassembly. The process of disassembling and reassembling the shaft and its components is not only time-consuming and labor-intensive, but some parts are also prone to damage during the process, leading to a significant increase in repair costs. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and equipment for on-site repair of external threads on shafts, which can repair the external threads on the shaft without disassembling it.

[0006] This invention is achieved through the following technical solution, providing a method for on-site repair of external threads on a shaft, comprising the following steps: a. Sequentially install a three-jaw chuck, a male thread template sleeve, and a female thread template sleeve onto the shaft to be repaired, and fix the male thread template sleeve to the three-jaw chuck. The end of the male thread template sleeve away from the three-jaw chuck is connected to the female thread template sleeve by a thread. The thread specification of the male thread template sleeve is consistent with the external thread to be repaired. A cutting tool is installed on the end of the female thread template sleeve away from the male thread template sleeve. b. Adjust the axial position of the three-jaw chuck so that the cutting edge of the cutting tool is opposite to the tooth groove of the external thread to be repaired. Then fix the three-jaw chuck to the shaft to be repaired to achieve the initial positioning of the axial position of the cutting tool. c. Adjust the radial position of the cutting tool so that the cutting edge of the cutting tool extends into the groove of the initial end of the external thread to be repaired, and fix the cutting tool to achieve the initial positioning of the radial position of the cutting tool; d. Rotate the female thread template sleeve in the forward direction, using it as the driving force for the cutting tool. At the same time, the connecting thread between the male and female thread template sleeves provides trajectory guidance for the cutting tool, causing it to move along the helical direction of the external thread to be repaired. The external thread to be repaired is then repaired during the tool's movement.

[0007] As an optimization, when the cutting tool moves axially to the end of the external thread to be repaired, the female end thread template sleeve is rotated in the opposite direction to move the cutting tool to the initial end of the external thread to be repaired. The cutting tool position is then adjusted radially inward before proceeding to step d. This optimized scheme further processes the already machined thread grooves using the cutting tool when the female end thread template sleeve is rotated in the opposite direction, avoiding defects such as burrs from affecting the use of the thread. By adjusting the cutting tool position radially inward, the thread is further repaired, making it suitable for repairing severely worn external threads.

[0008] This solution also provides an apparatus used in the above-mentioned method for on-site repair of external shaft threads. The apparatus includes a three-jaw chuck, a male thread template sleeve, and a female thread template sleeve arranged coaxially. One end of the male thread template sleeve is fixedly connected to the three-jaw chuck, and the other end is threadedly connected to the female thread template sleeve. A cutting tool is fixedly mounted on the end of the female thread template sleeve away from the male thread template sleeve.

[0009] When using the equipment in this solution, the three-jaw chuck is fixed to the shaft to be repaired, ensuring that the three-jaw chuck and the shaft to be repaired are coaxial. The connecting thread between the male end thread template sleeve and the female end thread template sleeve provides guidance for the movement of the cutting tool, so that the cutting tool can repair the external thread to be repaired without removing the shaft to be repaired from the equipment.

[0010] As an optimization, the male threaded template sleeve and the three-jaw chuck are detachably fixed together via an I-shaped plug. The I-shaped plug is inserted radially into the three-jaw chuck and the male threaded template sleeve. Each end of the three-jaw chuck and the male threaded template sleeve has a radially extending slot, forming a groove that fits the I-shaped plug. This optimized solution uses an I-shaped plug to connect the male threaded template sleeve and the three-jaw chuck, resulting in a simple structure, convenient assembly and disassembly, and improved efficiency in maintenance operations.

[0011] As an optimization, a magnet is fixed to the I-shaped plug, and the magnet is located inside the outline of the I-shaped plug. This optimization scheme, by setting the magnet, prevents the I-shaped plug from falling off by itself, ensuring the reliability of the connection between the male end thread template sleeve and the three-jaw chuck.

[0012] As an optimization, the cutting tool is connected to the female thread template sleeve via a radial adjustment device. The radial adjustment device includes a tool holder fixedly connected to the female thread template sleeve, and a tool sleeve that slides radially within the inner hole of the tool holder. The cutting tool passes through and is fixed within the inner hole of the tool sleeve, with its cutting edge facing the side of the shaft to be repaired. A radially extending feed bolt is threaded to the end of the tool holder away from the cutting edge. The end of the feed bolt located within the tool holder is rotatably connected to the tool sleeve. The cross-sectional profile of the tool sleeve has at least one straight section, and the inner hole of the tool holder is adapted to the tool sleeve. This optimized radial adjustment device facilitates adjustment of the radial position of the cutting tool to meet the requirements of thread repair machining for different groove depths.

[0013] As an optimization, at least one side wall of the tool holder has a radially extending elongated hole, through which a fixing bolt passes. The fixing bolt passes through the side wall of the tool holder and abuts against the cutting tool, and the fixing bolt is threadedly connected to the side wall of the tool holder. This optimized solution uses a fixing bolt to fix the cutting tool and the tool holder together, resulting in a simple structure and more convenient operation.

[0014] As an optimization, several circumferentially evenly distributed force-applying rods are fixed to the outer wall of the female threaded template sleeve, and these force-applying rods extend radially away from the female threaded template sleeve. This optimization scheme, by setting the force-applying rods, makes it easier to rotate the female threaded template sleeve.

[0015] The beneficial effects of this invention are as follows: by fixing the cutting tool on the female end thread template sleeve, the rotation and axial movement of the female end thread template sleeve drive the cutting tool to rotate and move axially, transforming the machining trajectory of the external thread to be repaired into the connecting thread between the female end thread template sleeve and the male end thread template sleeve, thereby allowing the cutting tool to move along the helical groove of the external thread to be repaired without disassembling the shaft where the external thread to be repaired is located, which greatly improves the working efficiency of shaft repair. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; As shown in the figure: 1. Three-jaw chuck; 2. Male end thread template sleeve; 3. Female end thread template sleeve; 4. Tool post; 5. Feed bolt; 6. Fixing bolt; 7. Tool sleeve; 8. Lathe tool; 9. Shaft to be repaired; 10. Force bar; 11. I-shaped plug. Detailed Implementation

[0017] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0018] like Figure 1The equipment used in the on-site repair method for external threads on a shaft, as shown, includes a three-jaw chuck 1, a male thread template sleeve 2, and a female thread template sleeve 3, all coaxially arranged. The inner holes of the three-jaw chuck, the male thread template sleeve, and the female thread template sleeve are coaxial, and the inner diameters of all three are larger than the diameter of the shaft to be repaired. The three-jaw chuck uses existing technology, and its structure will not be described in detail.

[0019] One end of the male thread template sleeve 2 is fixedly connected to the three-jaw chuck 1, and the other end is connected to the female thread template sleeve 3 by threads. The male thread template sleeve 2 is provided with external threads, and the female thread template sleeve 3 is provided with internal threads. The external thread of the male thread template sleeve 2 is consistent with the specification of the external thread to be repaired. A cutting tool 8 is fixedly installed on the end of the female thread template sleeve 3 away from the male thread template sleeve.

[0020] For ease of operation, the male threaded template sleeve 2 and the three-jaw chuck 1 are detachably fixed in this embodiment. Specifically, the male threaded template sleeve and the three-jaw chuck are detachably fixed via an I-shaped plug 11. The I-shaped plug 11 is inserted radially into the three-jaw chuck and the male threaded template sleeve. The adjacent ends of the three-jaw chuck and the male threaded template sleeve each have radially extending slots, forming grooves that fit the I-shaped plug. The flanges at both ends of the I-shaped plug prevent axial relative displacement between the male threaded template sleeve and the three-jaw chuck, and the middle cover plate of the I-shaped plug prevents circumferential relative rotation between them, thus achieving relative fixation between the three-jaw chuck and the male threaded template sleeve. Furthermore, using the I-shaped plug to fix the three-jaw chuck and the male threaded template sleeve makes assembly and disassembly simple and quick.

[0021] A magnet is fixed to the I-shaped plug, and the magnet is located inside the outline of the I-shaped plug to prevent the magnet from affecting the installation of the I-shaped plug. In this embodiment, the use of a magnet ensures the secure installation of the I-shaped plug and prevents it from falling out of the slot.

[0022] In order to achieve radial feed of the cutting tool and meet the repair requirements of the external thread with large wear, the cutting tool 8 in this embodiment is connected to the female end thread template sleeve through a radial adjustment device. Specifically, the radial adjustment device includes a tool holder 4 fixedly connected to the female end thread template sleeve, and a tool sleeve 7 that slides radially in the inner hole of the tool holder. The cutting tool 8 is fixedly inserted into the inner hole of the tool sleeve, with the cutting edge of the cutting tool facing the side where the shaft 9 to be repaired is located, and the inner hole of the tool sleeve is adapted to the cutting tool.

[0023] The end of the tool holder furthest from the cutting edge of the cutting tool is connected by a radially extending feed bolt 5 via a threaded connection. The end of the feed bolt 5 located inside the tool holder is rotatably connected to the tool sleeve 7. The cross-sectional profile of the tool sleeve has at least one straight section. The inner hole of the tool holder 4 is adapted to the tool sleeve 7 to prevent the tool sleeve from rotating with the feed bolt. In this embodiment, the cross-sectional profile of the tool sleeve is rectangular. By rotating the feed bolt, the radial position of the tool sleeve is adjusted, thereby adjusting the radial position of the cutting tool.

[0024] At least one side wall of the tool holder has a radially extending elongated hole, through which a fixing bolt 6 passes. The fixing bolt 6 passes through the side wall of the tool holder and abuts against the cutting tool 8. The fixing bolt is threadedly connected to the side wall of the tool holder. In this embodiment, the elongated hole is located on the vertical side wall of the tool holder away from the female end threaded template sleeve, which facilitates operation.

[0025] The tool holder includes a horizontal section and a vertical section that are perpendicular to each other and fixedly connected. In this embodiment, the horizontal section and the vertical section are a single piece. A connecting plate opposite to the horizontal section is fixedly connected to the outer surface of the female threaded template sleeve. The horizontal section and the connecting plate are fixedly connected by bolts. The feed bolt 5, the inner hole adapted to the tool holder, and the elongated hole are all located in the vertical section.

[0026] To facilitate manual rotation, several circumferentially evenly distributed force-applying rods 10 are fixed to the outer wall of the female threaded template sleeve. The force-applying rods 10 extend radially away from the female threaded template sleeve. In this embodiment, there are two force-applying rods, which are coaxial in the diametrical direction.

[0027] This embodiment of a method for on-site repair of external shaft threads includes the following steps: a. Sequentially mount a three-jaw chuck 1, a male thread template sleeve 2, and a female thread template sleeve 3 onto the shaft 9 to be repaired. Fix the male thread template sleeve 2 to the three-jaw chuck 1. The end of the male thread template sleeve 2 away from the three-jaw chuck is connected to the female thread template sleeve 3 by a thread. The thread specification of the male thread template sleeve is consistent with the external thread to be repaired. A cutting tool 8 is installed on the end of the female thread template sleeve away from the male thread template sleeve.

[0028] b. Adjust the axial position of the three-jaw chuck 1 on the shaft to be repaired so that the cutting edge of the cutting tool is radially opposite to the tooth groove of the external thread to be repaired. Then, by rotating the fastening device of the three-jaw chuck in sequence, fix the three-jaw chuck to the shaft to be repaired to achieve the initial axial position positioning of the cutting tool and avoid relative displacement of the equipment on the shaft to be repaired.

[0029] c. Adjust the radial position of the cutting tool so that the cutting edge extends into the groove of the initial end of the external thread to be repaired, and fix the cutting tool to achieve the initial radial position positioning of the cutting tool.

[0030] d. Manually rotate the female end thread template sleeve 3 in the forward direction. When the female end thread template sleeve moves, it drives the cutting tool to rotate synchronously. The connecting thread between the male end thread template sleeve and the female end thread template sleeve provides trajectory guidance for the cutting tool 8. Since the thread pitch of the male end thread template sleeve is consistent with the pitch of the external thread to be repaired, the cutting tool moves along the helical direction of the external thread to be repaired. The external thread to be repaired is repaired during the movement of the cutting tool.

[0031] When the cutting tool moves axially to the end of the external thread to be repaired, the female end thread template sleeve is rotated in the opposite direction to move the cutting tool to the initial end of the external thread to be repaired. Then, the cutting tool position is adjusted radially inward, and step d is repeated until the tooth height of the external thread to be repaired meets the requirements. During the reverse rotation of the female end thread template sleeve, the cutting tool further processes the already machined thread to avoid defects such as burrs affecting the use of the thread.

[0032] The solution in this embodiment allows for on-site machining and repair of external threads on shafts, eliminating the need for complete disassembly and transfer to a lathe. This skips the time-consuming, labor-intensive, and complex disassembly and installation process, significantly improving maintenance efficiency. Furthermore, the equipment in this embodiment has a wide range of applications, suitable for machining external threads of different pitches and directions. It only requires the use of male and female thread templates of the same specifications. Machining the male and female thread templates is both time-saving and labor-saving compared to disassembling and assembling shaft components.

[0033] Of course, the above description is not limited to the examples above. Technical features not described in this invention can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solutions of this invention and are not intended to limit this invention. This invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention do not depart from the spirit of this invention and should also fall within the scope of protection of the claims of this invention.

Claims

1. A method for on-site repair of external threads on a shaft, characterized in that, Includes the following steps: a. Sequentially install a three-jaw chuck (1), a male thread template sleeve (2), and a female thread template sleeve (3) onto the shaft (9) to be repaired. Fix the male thread template sleeve (2) to the three-jaw chuck (1). The end of the male thread template sleeve (2) away from the three-jaw chuck is connected to the female thread template sleeve (3) by threads. The thread specification of the male thread template sleeve is consistent with the external thread to be repaired. A cutting tool (8) is installed on the end of the female thread template sleeve away from the male thread template sleeve. b. Adjust the axial position of the three-jaw chuck (1) so that the cutting edge of the cutting tool is opposite to the tooth groove of the external thread to be repaired, and then fix the three-jaw chuck to the shaft to be repaired. c. Adjust the radial position of the cutting tool so that the cutting edge of the cutting tool extends into the groove of the initial end of the external thread to be repaired, and then fix the cutting tool. d. Rotate the female end thread template sleeve (3) in the forward direction. Use the connecting thread between the male end thread template sleeve and the female end thread template sleeve to provide trajectory guidance for the cutting tool (8), so that the cutting tool moves along the helical direction of the external thread to be repaired. Repair the external thread to be repaired during the movement of the cutting tool.

2. The method for on-site repair of external shaft threads according to claim 1, characterized in that: When the cutting tool moves axially to the end of the external thread to be repaired, rotate the female end thread template sleeve in the opposite direction to move the cutting tool to the initial end of the external thread to be repaired, adjust the position of the cutting tool radially inward, and then proceed to step d.

3. An apparatus used in the method for on-site repair of external shaft threads as described in claim 1, characterized in that: It includes a three-jaw chuck (1) set coaxially, a male thread template sleeve (2) and a female thread template sleeve (3). One end of the male thread template sleeve (2) is fixedly connected to the three-jaw chuck (1), and the other end is connected to the female thread template sleeve (3) by thread. A cutting tool (8) is fixedly mounted on the end of the female thread template sleeve (3) away from the male thread template sleeve.

4. The equipment used in the method for on-site repair of external shaft threads according to claim 3, characterized in that: The male end thread template sleeve and the three-jaw chuck are detachably fixed together by an I-shaped plug (11). The I-shaped plug (11) is inserted radially into the three-jaw chuck and the male end thread template sleeve. The three-jaw chuck and the male end thread template sleeve are respectively provided with radially extending slots at their adjacent ends. The slots on the three-jaw chuck and the male end thread template sleeve form a groove that is compatible with the I-shaped plug.

5. The equipment used in the method for on-site repair of external shaft threads according to claim 4, characterized in that: A magnet is fixed on the I-shaped plug, and the magnet is located inside the outline of the I-shaped plug.

6. The equipment used in the method for on-site repair of external shaft threads according to claim 3, characterized in that: The cutting tool (8) is connected to the female end threaded template sleeve through a radial adjustment device. The radial adjustment device includes a tool holder (4) fixedly connected to the female end threaded template sleeve, and a tool sleeve (7) that slides radially in the inner hole of the tool holder. The cutting tool (8) is fixedly inserted in the inner hole of the tool sleeve, and the cutting edge of the cutting tool faces the side where the shaft (9) to be repaired is located. The end of the tool holder away from the cutting edge of the cutting tool is connected by a feed bolt (5) that extends radially through a thread. The end of the feed bolt (5) located in the tool holder is rotatably connected to the tool sleeve (7). The cross-sectional profile of the tool sleeve has at least one straight section. The inner hole of the tool holder (4) is adapted to the tool sleeve (7).

7. The equipment used in the method for on-site repair of external shaft threads according to claim 6, characterized in that: At least one side wall of the tool holder is provided with a radially extending elongated hole, and a fixing bolt (6) is inserted through the elongated hole. The fixing bolt (6) passes through the side wall of the tool holder and abuts the cutting tool (8). The fixing bolt is threadedly connected to the side wall of the tool holder.

8. The equipment used in the method for on-site repair of external shaft threads according to claim 3, characterized in that: The outer wall of the female end threaded template sleeve is fixed with a number of circumferentially evenly distributed force rods (10), which extend radially away from the female end threaded template sleeve.

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