Anti-locking structure for disassembly of flat key taper shaft

Abstract

The invention belongs to the technical field of assembly and disassembly of taper shafts, discloses an anti-jamming structure for disassembly of a flat key taper shaft, particularly relates to the technical problem that the taper shaft provided with a flat key is difficult to disassemble in the disassembly process, and provides a solving method. Aiming at different problems occurring in three stages when the taper shaft is disassembled, the principle of difficult disassembly is elaborated, and a solution method is provided. The method is suitable for a taper shaft longer than a flat key used by the method, and the flat key is parallel to the center line of the taper shaft. According to the structure, a stop pin is arranged in a key groove of a flat key parallel to a taper shaft and at the end of the key groove on the small conical surface side, the height of the stop pin is that the bottom of the key groove serves as a starting point, the total height cannot be larger than the thickness of the flat key, the shortest value is larger than the height of the small conical surface end of the key groove, and the diameter or width cannot be larger than the width of the key groove; and the shearing force borne in the dismounting process is met. According to the taper shaft assembled through the taper shaft assembling tool, the phenomenon that the taper shaft is clamped or stuck in the disassembling process is avoided.

Description

Technical Field

[0001] This invention relates to the field of tapered shaft assembly and disassembly technology, and in particular to a structure for preventing jamming during the disassembly of a tapered shaft with a flat key, which solves the problem of difficulty in disassembling a tapered shaft equipped with a flat key. Background Technology

[0002] The use of a tapered shaft and a matching tapered sleeve is a common method in mechanical fitting, offering the significant advantage of quick disassembly and assembly. Tapered shafts with a keyed structure are a primary method in tapered assembly. There are two types of key-sleeve pairings: one where the key surface is parallel to the tapered surface of the shaft, and another where it is parallel to the shaft's centerline. However, long tapered shafts with a key parallel to the shaft's centerline are particularly difficult to disassemble due to structural defects. They are generally considered to be jammed. While it's true that with the outward pulling force of the disassembly tool, theoretically the gap between the tapered shaft and the sleeve should increase, making disassembly easier. However, the disassembly tool still requires considerable force and a considerable distance to complete the disassembly, thus negating the advantages of easy assembly and disassembly of tapered shafts. National and industry standards lack clear explanations for this difficulty. This invention explicitly points out the reasons for this difficulty and provides corresponding solutions based on the principles. It provides theoretical support for the processing, use, and maintenance of such products in this industry. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a structure for disassembling a flat key tapered shaft to prevent jamming. It provides the principle that tapered shafts are difficult to disassemble and, based on this principle, provides a method that solves the technical problem of the difficulty in disassembling tapered shafts of this type.

[0004] The objective of this invention is achieved as follows: a tapered shaft anti-jamming structure, comprising: a stop pin provided in the keyway of the tapered shaft near the small conical surface end of the keyway, the stop pin being installed on the tapered shaft; the overall structure also includes a tapered shaft, a flat key, end fixing bolts, a baffle, a tapered shaft sleeve; the tapered shaft and the tapered shaft sleeve are fitted together by a tapered fit, with a flat key in between, to ensure a tight fit between the power output end and the power usage end.

[0005] The length of the tapered shaft is greater than the length of the flat key it mates with.

[0006] The angle between the taper shaft flat keyway and the taper shaft is parallel to the center line of the taper shaft.

[0007] The keyway has a stop pin near the small conical end. The height of the stop pin is such that the total height, starting from the bottom of the keyway, cannot exceed the thickness of the flat key. The shortest value is greater than the height of the small conical end of the keyway. The diameter or width cannot exceed the width of the keyway. The stop pin also has corresponding mechanical strength to meet the shearing force it can withstand during disassembly.

[0008] The stop pin provided near the small conical surface of the keyway has a width that cannot exceed the width of the keyway and has corresponding mechanical strength to meet the shearing force it can withstand during disassembly.

[0009] The tapered bushing has a flat keyway of the same standard as the tapered shaft, with the angle of the keyway parallel to the center line of the tapered hole structure, and the length suitable for the flat key with a stop pin, while retaining a suitable clearance.

[0010] The assembly structure of the tapered shaft also includes a tapered shaft end baffle and fastening bolts.

[0011] When the assembly structure of the tapered shaft is disassembled, a puller auxiliary mechanism is connected.

[0012] A structure for preventing jamming during disassembly of a flat key tapered shaft is presented. The tapered shaft requires auxiliary tools such as pullers during disassembly. The following analysis addresses the problems encountered during disassembly, their causes, and the proposed solutions based on the principles involved, based on the three stages of the disassembly process.

[0013] In the first stage, the disassembly structure consisting of top bar 22, top plate 23, and pressure bolt 24 gradually applies an initial breaking force to the tapered shaft and tapered sleeve through the top plate and top bar. The direction of the first force 1 coincides with the center line 11. At this time, the pressure of the bolt, i.e. the breaking force, is fully applied between the tapered sleeve and the tapered shaft, forcing the tapered shaft and the tapered sleeve to separate.

[0014] In the second stage, the clamping bolt 24 continues to apply pressure, and the tapered sleeve continues to separate from the shaft. Since it is a tapered shaft, a gap exists between the tapered sleeve and the tapered shaft. When this gap is greater than the height of the keyway at point 7, the height of the keyway is generally about 2 mm and is semi-circular, as shown in the attached diagram. Figure 3 As shown, the flat key will jump out of the keyway. The reason for jumping out of the taper shaft keyway is that the 2 mm keyway cannot stop the movement of the flat key. The example listed here is that the diameter of the large taper side is 80 mm, the taper is 1:20, the shaft length is 350 mm, the flat key is a national standard key with a key width of 24 mm, a key thickness of 14 mm, and a key length of 180 mm. Because the flat key is parallel to the center line of the taper shaft, the keyway height at point 7 is 2 mm.

[0015] In the third stage, after the flat key jumps out of the keyway, it will move along with the tapered bushing. This is because the mating surface 20 of the key sleeve to the flat key is larger than the mating surface 21 of the tapered shaft to the flat key. Furthermore, the flat key has already released its mating relationship with the tapered shaft. The pressure bolt will continue to apply pressure, and the tapered bushing will continue to separate from the shaft. The flat key will move outward with the tapered bushing. At this point, the bottom of the flat key will contact the tapered shaft's locking point 7. The locking point 7 is a sharp semi-circle. At this time, the resistance to pulling out the clamping bolt 24 begins to increase. The mechanical relationship between the tapered shaft, tapered bushing, flat key, and clamping bolt is as shown in the attached figure. Figure 4 .

[0016] See appendix Figure 4 The disassembly force from the tightening bolts originates in the direction of the first force (1), which is transmitted through the top plate to the tapered shaft. At the contact point between the tapered shaft and the top rod, this first force is decomposed into three forces: the second force (2) is transmitted through the tapered shaft to the flat key; the third force (3) is the force for disassembling the tapered shaft, which is beneficial to the disassembly work; and the fourth force (4) is a component of the first force (1) and the second force (2), causing the tapered shaft to adhere tightly to the lower wall of the tapered sleeve. The addition of the fourth force will cause the tapered shaft to make close contact with the lower wall of the tapered sleeve, increasing friction and making disassembly more difficult.

[0017] The second force, direction 2, is decomposed into two forces at point 7. The fifth force, 5, forces the flat key to press tightly against the tapered sleeve, while the sixth force, 6, forces the flat key to exit the keyway along its direction. The first force, due to the resistance at point 7, is forced to increase. Transmitted through the second force, the fifth and sixth forces increase accordingly. The fifth force increases the contact pressure between the flat key and the tapered sleeve, leading to increased friction and making disassembly more difficult. Therefore, the fifth and sixth forces are not beneficial forces; they only increase the difficulty of disassembly.

[0018] See appendix for the fourth stage. Figure 5 As the pressure increases, the tapered bushing continues to separate from the tapered shaft, creating a gap 1202 between them. At this point, the angle 8 increases, and the force transmitted from the first force 1 to the fifth force 5 and the sixth force 6 via the second force 2 becomes greater, increasing the harmful force. The harmful force of the fourth force 4 also increases, while the third force 3, which is beneficial for disassembly, decreases, making disassembly more difficult and sometimes causing jamming. In coal mines, explosives were once used to separate the parts.

[0019] Therefore, based on the above principles, a solution is proposed. A structure for preventing jamming during disassembly of a flat key tapered shaft includes a stop pin located near the small conical surface of the keyway. The stop pin's height is [value missing], with the bottom of the keyway as the starting point. The total height cannot exceed the thickness of the flat key, and the shortest value is [value missing]. The stop pin's height is greater than the height of the small conical surface of the keyway. The diameter or width of the stop pin cannot exceed the width of the keyway, and it has corresponding mechanical strength to withstand the shearing force during disassembly.

[0020] This ensures that the flat key will not move outward with the tapered sleeve during the disassembly process, effectively preventing it from getting stuck.

[0021] The flat key above corresponds to the one above, because during actual disassembly, employees are accustomed to judging the disassembly process and result of the tapered shaft by observing whether the flat key moves. This is to cultivate employee habits. The up and down and positions mentioned in the text and in the attached diagrams are all based on this reason.

[0022] The present invention has the following beneficial effects: During the disassembly of the tapered shaft, as long as the initial breaking force of the tapered shaft is overcome, the disassembly of the tapered shaft is successful, which reduces the labor intensity of the workers.

[0023] More disassembly options are provided to employees. Disassembling the tapered shaft can be done by increasing the pulling force or pressure, and vibration is also used in conjunction with it. This is the best auxiliary method for disassembling the tapered shaft. In the existing unimproved structure, if it is stuck, the vibration method is extremely ineffective and will also increase the damage to the equipment.

[0024] Because they were difficult to disassemble, the tapered shafts were not previously installed and tightened according to standards, for fear of making disassembly difficult. Once the problem of difficulty in disassembly is solved, maintenance workers will install them according to standards, reducing operational failures.

[0025] This problem with mining gearboxes of this structure has remained unresolved for 30 years; the difficulty in disassembling it has hindered the promotion and use of the product, leading to its gradual withdrawal from the market.

[0026] This invention explains the reason for the difficulty in disassembly through its principles, providing theoretical and principled support for the design of other similar structures in the future, thus enabling the continued widespread adoption of this structure. Based on this principle, other technicians can also develop other solutions.

[0027] National and industry standards lack specific documentation explaining the reasons for the difficulty in disassembly. This invention clearly identifies the cause and proposes corresponding solutions based on the underlying principles. It provides theoretical support for the processing, use, and maintenance of such products in this industry. Attached Figure Description

[0028] Figure 1 A schematic diagram of the specific implementation structure; Figure 2 This is a schematic diagram of a disassembly structure; Figure 3 This is a schematic diagram of the checkpoint structure and its enlarged portion; Figure 4 This is the schematic diagram for the second stage; Figure 5 This is the schematic diagram for the third stage; Figure 6 Explanation of the mating surfaces of the flat key, tapered sleeve, and tapered shaft; Explanation of reference numerals in the attached diagram: 1. Direction of the first force; 2. Direction of the second force; 3. Direction of the third force; 4. Direction of the fourth force; 5. Direction of the fifth force; 6. Direction of the sixth force; 7. Clamping point; 8. Angle; 9. Upper wall of the tapered tube; 10. Lower wall of the tapered tube; 11. Centerline; 1201. First gap; 1202. Second gap; 13. Tapered shaft wall; 14. Stop pin; 15. Flat key; 16. Tapered shaft; 17. Bolt; 18. Baffle; 19. Tapered shaft sleeve; 20. Mating surface of flat key and tapered shaft sleeve; 21. Mating surface of flat key and tapered shaft; 22. Top bar; 23. Top plate; 24. Disassembly pressure bolt. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings, and examples of the technical solutions in the embodiments of the present invention will be provided.

[0030] As attached Figure 2 As shown, in the first stage, the disassembly structure consisting of top bar 22, top plate 23, and pressure bolt 24 gradually applies an initial breaking force to the tapered shaft and tapered sleeve through the top plate and top bar. The direction 1 of the first force coincides with the center line 11. At this time, the pressure of the bolt, i.e. the breaking force, is fully applied between the tapered sleeve and the tapered shaft, forcing the tapered shaft and the tapered sleeve to separate.

[0031] In the second stage, the clamping bolt 24 continues to apply pressure, and the tapered sleeve continues to separate from the shaft. Since it is a tapered shaft, a gap exists between the tapered sleeve and the tapered shaft. When this gap is greater than the height of the keyway at point 7, the height of the keyway is generally about 2 mm and is semi-circular, as shown in the attached diagram. Figure 3 As shown, the flat key will jump out of the keyway. The reason for jumping out of the taper shaft keyway is that the 2 mm keyway cannot stop the movement of the flat key. The example here is that the diameter of the large taper side is 80 mm, the taper is 1:20, the shaft length is 350 mm, the flat key is a national standard key with a width of 24 mm, a thickness of 14 mm, and a length of 180 mm. Because the flat key is parallel to the center line of the taper shaft, the keyway height at point 7 is 2 mm.

[0032] In the third stage, after the flat key jumps out of the keyway, it will move along with the tapered bushing. This is because the mating surface 20 of the key sleeve to the flat key is larger than the mating surface 21 of the tapered shaft to the flat key. Furthermore, the flat key has already released its mating relationship with the tapered shaft. The pressure bolt will continue to apply pressure, and the tapered bushing will continue to separate from the shaft. The flat key will move outward with the tapered bushing. At this point, the bottom of the flat key will contact the tapered shaft's locking point 7. The locking point 7 is a sharp semi-circle. At this time, the resistance to pulling out the clamping bolt 24 begins to increase. The mechanical relationship between the tapered shaft, tapered bushing, flat key, and clamping bolt is as shown in the attached figure. Figure 4 .

[0033] Participate in the attached Figure 4The disassembly force from the tightening bolts originates in the direction of the first force (1), which is transmitted through the top plate to the tapered shaft. At the contact point between the tapered shaft and the top rod, this first force is decomposed into three forces: the second force (2) is transmitted through the tapered shaft to the flat key; the third force (3) is the force for disassembling the tapered shaft, which is beneficial to the disassembly work; and the fourth force (4) is a component of the first force (1) and the second force (2), causing the tapered shaft to adhere tightly to the lower wall of the tapered sleeve. The addition of the fourth force will cause the tapered shaft to make close contact with the lower wall of the tapered sleeve, increasing friction and making disassembly more difficult.

[0034] The second force, 2, is decomposed into two forces at the jamming point 7. The fifth force, 5, forces the flat key tightly against the tapered sleeve. This fifth force increases the contact pressure between the flat key and the tapered sleeve, thereby increasing friction and making disassembly more difficult. The sixth force, 6, forces the flat key out of the keyway along the keyway direction. The first force, due to the resistance at jamming point 7, is forced to increase. Through the transmission of the second force, the fifth and sixth forces increase accordingly. These fifth and sixth forces are non-beneficial forces, further increasing the difficulty of disassembly.

[0035] See appendix for the fourth stage. Figure 5 As the pressure increases, the tapered bushing continues to separate from the tapered shaft, creating a gap 1202 between them. At this point, the angle 8 increases, and the force transmitted from the first force 1 to the fifth force 5 and the sixth force 6 via the second force 2 becomes greater, increasing the harmful force. The harmful force of the fourth force 4 also increases, while the third force 3, which is beneficial for disassembly, decreases, making disassembly more difficult and sometimes causing jamming. In coal mines, explosives were once used to separate the parts.

[0036] The following technical solution is provided: A stop pin 14 is provided in the keyway of the tapered shaft 16 near the small conical surface end of the keyway, and the stop pin 14 is installed on the tapered shaft 16. The overall structure also includes the tapered shaft 16, a flat key 15, end fixing bolts 17, a baffle 18, and a tapered shaft sleeve 19. The tapered shaft and tapered shaft sleeve are the output ends of two different power sources, respectively. Through tapered fit and with the flat key 15 in between, the power output end and the power user end are tightly fitted together.

[0037] The stop pin 14 is set at the end of the keyway near the small conical surface. Its height is [value missing]. Starting from the bottom of the keyway, the total height cannot be higher than the thickness of the flat key. The minimum value is [value missing]. It is greater than the height of the small conical surface end of the keyway. Its diameter or width cannot be greater than the width of the keyway. It also has corresponding mechanical strength to meet the shearing force it can withstand during disassembly.

[0038] The width of the stop pin 14 must not exceed the width of the keyway, and must not affect the installation of the tapered sleeve.

[0039] The total length of the flat key 15 plus the stop pin should be equivalent to the length of the taper shaft keyway, and also equivalent to the length of the keyway inside the taper sleeve.

[0040] The angle of the keyway of the flat key 15 should be parallel to the center line of the tapered shaft, and the angle of the keyway of the tapered bushing should be parallel to the center line of the tapered hole.

[0041] Disassembly requires the use of tools such as pullers. The force that the puller needs to break during disassembly is the initial breaking force of the taper shaft and taper sleeve. After breaking the breaking force, the next force that the puller needs to break is the friction between the mating surfaces of the flat key and the taper sleeve. At this point, a very small force is needed to easily separate the taper sleeve and the taper shaft.

[0042] This invention provides employees with more disassembly options during the disassembly of tapered shafts. The disassembly of tapered shafts can be combined with increased tension or pressure, as well as vibration, which is the best auxiliary method for disassembling tapered shafts. This overcomes the initial breaking force of the tapered shaft, making it easy to disassemble successfully and reducing the labor intensity of workers.

[0043] The existing, unimproved structure, once stuck, renders vibration methods ineffective and may even increase equipment damage. Previously, the tapered shaft was not tightened to standard due to its difficulty in disassembly, fearing the risk of further damage. Solving this disassembly issue will allow maintenance workers to install it according to standards, reducing operational malfunctions.

[0044] For 30 years, the difficulty in disassembling this type of mining gearbox has hindered its widespread adoption and use, leading to its gradual withdrawal from the market. This invention explains the reason for this disassembly difficulty through its underlying principles, providing theoretical and principled support for the design of other similar structures, thus enabling the continued widespread adoption of this design. Based on this principle, other technicians can also develop other solutions.

[0045] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A structure for preventing jamming during disassembly of a flat key tapered shaft, characterized in that, include: Inside the keyway of the tapered shaft, a stop pin is provided at the end of the keyway near the small tapered surface. The stop pin is installed on the tapered shaft. Its overall structure also includes a tapered shaft, a flat key, end fixing bolts, a baffle, a tapered shaft sleeve, and a tapered shaft and tapered shaft sleeve. Through the tapered fit and the addition of a flat key, the power output end and the power usage end are tightly fitted.

2. The anti-jamming structure for disassembling the flat key tapered shaft according to claim 1, characterized in that, The length of the tapered shaft is greater than the length of the flat key it mates with.

3. The anti-jamming structure for disassembling the flat key tapered shaft according to claim 1, characterized in that, The angle between the taper shaft flat keyway and the taper shaft is parallel to the center line of the taper shaft.

4. The anti-jamming structure for disassembling the flat key tapered shaft according to claim 1, characterized in that, The keyway has a stop pin near the small conical end. The height of the stop pin is such that the total height, starting from the bottom of the keyway, cannot exceed the thickness of the flat key. The shortest value is greater than the height of the small conical end of the keyway. The diameter or width cannot exceed the width of the keyway. The stop pin also has corresponding mechanical strength to meet the shearing force it can withstand during disassembly.

5. The anti-jamming structure for disassembling the flat key tapered shaft according to claim 1, characterized in that, The tapered bushing has a flat keyway of the same standard as the tapered shaft, with the angle of the keyway parallel to the center line of the tapered hole structure, and the length suitable for the flat key with a stop pin, while retaining a suitable clearance.

6. The anti-jamming structure for disassembling the flat key tapered shaft according to claim 1, characterized in that, The assembly structure of the tapered shaft also includes a tapered shaft end baffle and fastening bolts.

7. The anti-jamming structure for disassembling the flat key tapered shaft according to claim 1, characterized in that, When the assembly structure of the tapered shaft is disassembled, a puller auxiliary mechanism is connected.

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