Stud limiting anti-loosening structure and assembling method thereof

Abstract

The invention provides a double-end stud limiting and looseness-preventing structure and an assembling method thereof. The double-end stud limiting and looseness-preventing structure comprises a double-end stud (1), a fixing nut (3), a limiting gasket (4) and a fixing screw (5). The nut and the gasket which are connected through the double-end stud are integrally designed, nut limiting can be achieved, the structure is simplified, the function design of the limiting gasket is more comprehensive, the limiting gasket can be matched with a machine body structure limiting groove through the extending evenly-distributed limiting lug pieces, a plurality of bolt holes are evenly distributed to be used for limiting the limiting lug pieces of the double-end stud, and the service life of the limiting gasket is prolonged. Limiting measures are simple and feasible, the device is suitable for being used on a closed force transmission box section machine body structure, and system equipment installation on a closed box section is achieved.

Description

Technical Field

[0001] This invention belongs to the field of helicopter structural design, specifically relating to a double-headed stud limiting and anti-loosening structure and its assembly method. Background Technology

[0002] In order to transmit concentrated large loads, the airframe support structure at the connection points of helicopter mid-reduction and tail reduction systems generally needs to be designed as a closed box structure. Mid-reduction and tail reduction systems are generally connected by bolts and nuts embedded in the airframe support structure. If the common bolt + nut connection method is used, it will affect maintenance and use.

[0003] For ease of maintenance and use, and because opening maintenance access covers on the fuselage support structure would affect load transfer efficiency, the enclosed box sections on helicopters are currently typically connected by bolts and cylindrical nuts, brackets and self-made nuts, or double-ended studs. The nuts are embedded inside the enclosed box section, and the intermediate reduction gear, tail reduction gear, and landing gear joints are installed externally by bolts.

[0004] However, based on the experience of using the above solutions in the helicopter industry, the bolt + cylindrical nut connection method requires a large space to be reserved in the structure for drilling holes to install the nut, which will result in a significant weight cost. The plate + self-made nut connection method requires the nut to be installed on the plate in an enclosed space, which requires a large operating space and is relatively complicated. The double-ended stud connection method requires tightening the fixing nut in an enclosed space to fix the double-ended stud, which also requires a large operating space. At the same time, long-term use will cause the fixing nut to lose torque, and tightening the nut on the other side will cause the double-ended stud to loosen, affecting disassembly and assembly. Summary of the Invention

[0005] This invention provides a double-ended stud limiting and anti-loosening structure and its assembly method, providing a double-ended stud connection solution with simple and reasonable structure, which can realize quick assembly and disassembly in enclosed spaces and has anti-loosening and limiting functions.

[0006] The first aspect of this invention provides a double-ended stud limiting and anti-loosening structure, comprising: a double-ended stud 1, a fixing nut 3, a limiting washer 4, and a fixing screw 5; The diameter of the smooth rod on the body structure 2 side of the double-headed stud 1 is larger than the diameter of the smooth rod on the equipment connection side; A limiting lug extends from the nut in the middle of the double-ended stud 1, and the limiting lug is provided with multiple limiting through holes; The limiting gasket 4 is installed in the groove on the outside of the body structure 2, and a limiting structure with a concave-convex fit is provided between the limiting gasket 4 and the groove on the outside. The limiting washer 4 is fitted on the double-ended stud 1 and has multiple threaded holes evenly distributed around its circumference. The fixing screw 5 passes through a limiting through hole and a threaded hole to achieve the limiting of the double-ended stud 1. The fixing nut 3 is embedded in the groove on the inner side of the body structure 2. The profile of the fixing nut 3 matches the profile of the inner groove, and the fixing nut 3 and the inner groove are precisely fitted. The profiles of the fixing nut 3 and the inner groove are used for positioning. The light rod on the side of the body structure 2 of the double-headed stud 1 passes through the limiting washer 4, the body structure 2 and the fixing nut 3 and is connected.

[0007] Optionally, the number of limiting through holes is two; The angle A between the center of the two limiting through holes and the center of the double-ended stud is set according to the tightening torque value adjustment range of the double-ended stud 1; so as to ensure that after rotating the double-ended stud 1, one of the limiting through holes of the limiting lug on the double-ended stud 1 can be aligned with one of the threaded holes on the limiting washer 4.

[0008] Optionally, the included angle B = 2A is the line connecting the center of every two adjacent threaded holes and the center of the four holes of the limiting washer.

[0009] Optionally, the limiting pad 4 has three limiting bosses evenly distributed at 120° around its circumference, and the outer side of the body structure 2 has three straight grooves evenly distributed at 120° around its circumference that correspond to the limiting bosses, to prevent the limiting pad 4 from rotating.

[0010] Optionally, the fixing nut 3 is square.

[0011] Optionally, the fixing nut 3 is provided with a light-reducing hole.

[0012] Optionally, a threaded hole is provided in the middle of the fixing nut 3, and the threaded hole is connected to the surrounding surface through multiple support walls; The height of the threaded hole is determined according to the requirements of the threaded connection; the height of the surrounding profile is determined according to the bolt tightening torque.

[0013] Optionally, the height of the threaded hole is higher than the height of the surrounding profile.

[0014] A second aspect of the present invention provides an assembly method for a double-ended stud limiting and anti-loosening structure as described in any one of the first aspects, characterized in that it includes: First, insert the fixing nut 3 into the groove on the inner side of the body structure 2; Then, the limiting washer 4 is embedded in the groove on the outside of the body structure 2. The double-ended stud 1 is passed through the limiting washer 4, the body structure 2 and the fixing nut 3 and tightened with torque. The tightening torque value is adjusted within the tolerance range until one limiting through hole of the upper limiting lug of the double-ended stud 1 and one threaded hole on the limiting washer 4 are aligned. Finally, the double-ended stud 1 is fixed with the fixing screw 5, so that the double-ended stud 1 is fixed on the limiting washer 4, and the limiting washer 4 is fixed on the body structure 2.

[0015] In summary, the beneficial effects of the present invention are as follows: This invention provides a double-ended stud limiting and anti-loosening structure and its assembly method. The nut and washer connected by the double-ended stud are integrated into a single design, which not only limits the nut's position but also simplifies the structure. The limiting washer has a more comprehensive functional design, engaging with the limiting grooves in the machine body structure through protruding, evenly distributed limiting lugs, and also featuring several evenly distributed bolt holes for limiting the position with the double-ended stud limiting lugs. The limiting measure is simple and feasible, suitable for use on the machine body structure of enclosed force transmission box sections, enabling the installation of system equipment on enclosed box sections. This invention has a simple, reasonable, and feasible structure, possessing functions such as limiting and anti-loosening. This double-ended stud connection scheme has been successfully applied to enclosed large-load transmission box sections. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the double-headed stud limiting and anti-loosening structure of the present invention; Figure 2 Schematic diagram of fixing nut and limiting washer; Figure 3 This is a schematic diagram showing the installation of a double-ended stud on a limiting washer. Explanation of reference numerals in the attached figures: 1. Double-ended stud; 2. Body structure; 3. Fixing nut; 4. Limiting washer; 5. Fixing screw. Detailed Implementation

[0017] The following explanation, in conjunction with the accompanying drawings, details the double-ended stud limiting and anti-loosening structure and its assembly method provided by this invention.

[0018] like Figure 1-3 As shown, the present invention provides a double-ended stud limiting and anti-loosening structure and its assembly method.

[0019] This invention provides a double-ended stud limiting and anti-loosening structure, comprising: a double-ended stud 1, a fixing nut 3, a limiting washer 4, and a fixing screw 5; The diameter of the smooth rod on the body structure 2 side of the double-headed stud 1 is larger than the diameter of the smooth rod on the equipment connection side; A limiting lug extends from the nut in the middle of the double-ended stud 1, and the limiting lug is provided with multiple limiting through holes; The limiting gasket 4 is installed in the groove on the outside of the body structure 2, and a limiting structure with a concave-convex fit is provided between the limiting gasket 4 and the groove on the outside. The limiting washer 4 is fitted on the double-ended stud 1 and has multiple threaded holes evenly distributed around its circumference. The fixing screw 5 passes through a limiting through hole and a threaded hole to achieve the limiting of the double-ended stud 1. The fixing nut 3 is embedded in the groove on the inner side of the body structure 2. The profile of the fixing nut 3 matches the profile of the inner groove, and the fixing nut 3 and the inner groove are precisely fitted. The profiles of the fixing nut 3 and the inner groove are used for positioning. The light rod on the side of the body structure 2 of the double-headed stud 1 passes through the limiting washer 4, the body structure 2 and the fixing nut 3 and is connected.

[0020] Example: Double-ended stud integral structure as follows Figure 1 As shown, one side of the double-ended stud is installed on the machine body structure by a fixing nut, while the other side extends out for connection of the equipment.

[0021] The overall structure of the double-ended stud consists of a double-ended stud 1, a body structure 2, a fixing nut 3, a limiting washer 4, and a fixing screw 5.

[0022] To prevent the double-ended stud from loosening, the diameters of the guide rods on both sides of the double-ended stud 1 are designed differently. The diameter of the guide rod on the machine body structure 2 side is larger than that on the equipment connection side, and the tightening torque on the machine body structure 2 side is greater than that on the equipment connection side. This is the first measure to prevent the double-ended stud 1 from loosening.

[0023] A limiting lug extends from the nut in the middle of the double-ended stud 1. The limiting lug has two limiting through holes. The angle between the line connecting the center of the two limiting through holes and the center of the double-ended stud is A. The size of A is set according to the adjustment range of the tightening torque value of the double-ended stud. This ensures that after adjusting the double-ended stud by rotation, one of the through holes of the limiting lug on the double-ended stud can align with one of the threaded holes on the limiting washer 4. Then, the double-ended stud is fixed with the fixing screw 5 to prevent the double-ended stud 1 from loosening by rotation.

[0024] like Figure 2 As shown, the limiting pad 4 is installed in the groove of the body structure 2. To prevent the limiting pad 4 from rotating, three limiting ears are evenly distributed at 120° on the limiting pad 4. At the same time, three straight grooves that are compatible with the limiting ears are evenly distributed at 120° in the groove of the body structure 2 to prevent the limiting pad 4 from rotating.

[0025] The limiting washer 4 has several threaded holes evenly distributed on it. The angle between the line connecting the center of each pair of adjacent threaded holes and the center of the hole in the limiting washer 4 is B, where B=2A. When the double-ended stud 1 is rotated to apply torque, when the tightening torque just reaches the standard requirement, the through hole of the upper limiting lug of the double-ended stud 1 may not be completely aligned with the threaded hole on the limiting washer 4. The double-ended stud 1 can be slightly rotated and adjusted within the torque tolerance range to ensure that the fixing screw can pass through the through hole of the double-ended stud 1 and connect with the threaded hole on the limiting washer 4. If the upper limit lug of the double-ended stud 1 has only one through hole, when the double-ended stud 1 is tightened to torque, sometimes this through hole is exactly between the two threaded holes on the limit washer 4, far from both threaded holes. A large rotation angle is required to adjust the double-ended stud 1 so that the through hole of the double-ended stud 1 aligns with the threaded hole on the limit washer 4. This may cause the tightening torque of the double-ended stud 1 to exceed the tolerance range. Therefore, as needed, two or more through holes should be provided on the upper limit lug of the double-ended stud 1. This ensures that within the torque tolerance range, a slight rotation adjustment of the double-ended stud 1 allows the fixing screw to pass through the through hole of the double-ended stud 1 and connect with the threaded hole on the limit washer 4, thereby achieving the limit of the double-ended stud. The installation relationship between the double-ended stud 1 and the limit washer 4 is as follows: Figure 3 As shown.

[0026] When the double-ended stud 1 is rotated to apply torque, the torque can be coarsely adjusted by angle B, and finely adjusted by the two through holes of the upper limit lug on the double-ended stud 1. This ensures that the fixing screw can pass through the through hole of the double-ended stud 1 and connect with the threaded hole on the limit washer 4, thereby achieving the limiting of the double-ended stud. The installation relationship between the double-ended stud 1 and the limit washer 4 is as follows: Figure 3 As shown.

[0027] like Figure 2 As shown, the fixing nut 3 adopts an integrated design of nut and washer, and the fixing nut 3 is embedded in the groove on the inner side of the body structure 2. The fixing nut 3 and the groove on the inner side of the body structure 2 are precision matched. When the double-ended stud 1 and the fixing nut 3 are connected and tightened, the mating surface of the fixing nut 3 and the body structure 2 can be limited.

[0028] Optionally, a threaded hole is provided in the middle of the fixing nut 3, and the threaded hole is connected to the surrounding surface through multiple support walls; the height of the threaded hole is determined according to the requirements of the threaded connection; the height of the surrounding surface is determined according to the bolt tightening torque.

[0029] Optionally, the height of the threaded hole is higher than the height of the surrounding profile.

[0030] The overall installation process of the double-ended stud 1 is as follows: First, embed the fixing nut 3 into the inner groove of the body structure 2, then embed the limiting washer 4 into the outer groove of the body structure 2, pass the double-ended stud 1 through the body structure and connect it with the fixing nut 3 and tighten it with torque. Adjust the tightening torque value within the tolerance range until one through hole of the upper limit lug of the double-ended stud 1 and one threaded hole on the limiting washer 4 are aligned. Finally, use the fixing screw 5 to fix the double-ended stud 1. In this way, the double-ended stud 1 is fixed on the limiting washer 4, and the limiting washer 4 is fixed on the body structure 2.

[0031] This invention provides a simple, reasonable and feasible double-ended stud connection solution with functions such as limiting and anti-loosening. This double-ended stud connection solution has been successfully applied to enclosed large transport box sections.

Claims

1. A double-ended stud limiting and anti-loosening structure, characterized in that... ,include: Double-ended stud (1), fixing nut (3), limiting washer (4), fixing screw (5); The diameter of the smooth rod on the body structure (2) side of the double-headed stud (1) is larger than the diameter of the smooth rod on the equipment connection side; A limiting lug extends from the nut in the middle of the double-ended stud (1), and the limiting lug is provided with multiple limiting through holes; The limiting gasket (4) is installed in the groove on the outside of the body structure (2), and a limiting structure with a concave-convex fit is provided between the limiting gasket (4) and the groove on the outside; The limiting washer (4) is fitted on the double-ended stud (1) and has multiple threaded holes evenly distributed around its circumference. The fixing screw (5) passes through a limiting through hole and a threaded hole to achieve the limiting of the double-ended stud (1). The fixing nut (3) is embedded in the groove on the inner side of the body structure (2). The profile of the fixing nut (3) matches the profile of the inner groove, and the fixing nut (3) and the inner groove are precision fitted. The profile of the fixing nut (3) and the inner groove are limited. The light rod on the side of the body structure (2) of the double-headed stud (1) passes through the limiting washer (4), the body structure (2) and the fixing nut (3) for connection.

2. The double-ended stud limiting and anti-loosening structure according to claim 1, characterized in that... The number of limiting through holes is two; The angle A between the center of the two limiting through holes and the center of the double-ended stud is set according to the tightening torque value adjustment range of the double-ended stud (1) to ensure that after rotating the double-ended stud (1), one of the limiting through holes of the limiting lug on the double-ended stud (1) can be aligned with one of the threaded holes on the limiting washer (4).

3. The double-ended stud limiting and anti-loosening structure according to claim 2, characterized in that... The included angle B = 2A is the line connecting the center of each two adjacent threaded holes and the center of the limiting washer (4) hole.

4. The double-ended stud limiting and anti-loosening structure according to claim 1, characterized in that... The limiting pad (4) has three limiting bosses evenly distributed at 120° around its circumference. The outer side of the body structure (2) has three straight grooves evenly distributed at 120° around its circumference that are compatible with the limiting bosses, to prevent the limiting pad (4) from rotating.

5. The double-ended stud limiting and anti-loosening structure according to claim 1, characterized in that... The fixing nut (3) is square.

6. The double-ended stud limiting and anti-loosening structure according to claim 5, characterized in that... The fixing nut (3) is provided with a light-reducing hole.

7. The double-ended stud limiting and anti-loosening structure according to claim 6, characterized in that... The fixing nut (3) has a threaded hole in the middle, and the threaded hole is connected to the surrounding surface through multiple support walls; The height of the threaded hole is determined according to the requirements of the threaded connection; the height of the surrounding profile is determined according to the bolt tightening torque.

8. The double-ended stud limiting and anti-loosening structure according to claim 7, characterized in that... The height of the threaded hole is higher than the height of the surrounding surface.

9. An assembly method for a double-ended stud limiting and anti-loosening structure as described in any one of claims 1-8, characterized in that... ,include: First, the fixing nut (3) is embedded into the groove on the inner side of the body structure (2); Then, the limiting washer (4) is embedded in the groove on the outside of the body structure (2), the double-ended stud (1) is passed through the limiting washer (4), the body structure (2) and the fixing nut (3) and tightened to a torque. The tightening torque value is adjusted within the tolerance range until one limiting through hole of the upper limiting lug on the double-ended stud (1) and one threaded hole on the limiting washer (4) are aligned. Finally, the double-ended stud (1) is fixed with a fixing screw (5) so that the double-ended stud (1) is fixed on the limiting washer (4) and the limiting washer (4) is fixed on the body structure (2).

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