Anti-falling structure of spline shaft after butt joint

Abstract

The present application relates to a kind of spline connection anti-disengagement structure, including front spline shaft (1), rear spline shaft (2), snap ring (6), nut (8), shaft coupling (7), anti-rotation spindle (9), spring (10) and spring seat (3), the outer spline structure of anti-rotation spindle is matched with the inner spline of shaft coupling, further limit shaft coupling cannot rotate after being screwed, realize the function that shaft coupling connects front spline shaft with rear spline shaft and cannot be self-disengaged.The present application reduces the difficulty of assembly process under the premise of ensuring the reliability of spline shaft connection, does not need to control the tightening angle of shaft bolt, and all parts are designed as rotary body symmetrical structure, avoid the adverse effects caused by vibration when rotor works.

Description

Technical Field

[0001] This invention relates to the field of mechanical transmission technology, specifically to an anti-detachment structure for splined shafts after docking, particularly an anti-detachment structure with full rotational symmetry. Background Technology

[0002] After the two rotors of an aero-engine are connected by internal and external splines, they tend to separate under axial working loads. To prevent this dangerous situation from occurring, an anti-separation structure must be designed. The common approach is to use a coupling screw and to prevent the coupling screw from rotating by threading.

[0003] Current methods for preventing rotation of coupling screws typically employ a locking cup with a punch-lock mechanism. However, this approach presents challenges for engine assembly. Firstly, the rotor's central shaft contains deep holes, making accurate punch-locking difficult. Secondly, after punch-locking, it's inconvenient to inspect the punch-lock surface for potential quality issues such as cracks. Furthermore, the punch-lock method is detrimental to the reliability of rotor connections under complex, high-load conditions. Summary of the Invention

[0004] The purpose of this invention is to overcome assembly difficulties, avoid designing parts with asymmetrical structures, and improve the operational reliability of the connecting device.

[0005] The technical solution of this invention is:

[0006] A structure for preventing the splined shafts from coming loose after mating is provided, comprising a front splined shaft 1, a rear splined shaft 2, a retaining ring 6, a nut 8, a coupling threaded sleeve 7, an anti-rotation mandrel 9, a spring 10, and a spring seat 3;

[0007] The rear end of the front spline shaft 1 is a hollow shaft structure with external splines, and the center of the front end of the rear spline shaft 2 is a three-step hole, which consists of an internal spline hole, an internal thread hole, and an internal hexagonal hole from the outside to the inside; the external spline at the rear end of the front spline shaft 1 and the internal spline hole at the front end of the rear spline shaft 2 are connected by a spline; the first step surface is between the internal spline hole and the internal thread hole;

[0008] The coupling sleeve is a hollow shaft with an internal spline inside and an external thread outside. One end of the coupling sleeve forms an outward flange, and the outer diameter of the outward flange is larger than the inner diameter of the retaining ring 6. The retaining ring 6 is installed in the hollow shaft structure at the rear end of the front spline shaft 1.

[0009] The outer flange of the coupling sleeve is located inside the hollow shaft structure at the rear end of the front spline shaft 1, and is axially limited by the retaining ring and cannot move axially. The external thread of the coupling sleeve is threadedly connected to the internal thread hole at the center of the front end of the rear spline shaft 2. The nut is threadedly engaged with the external thread of the coupling sleeve, and the nut is limited between the outer flange and the first stepped surface. The nut also radially limits the retaining ring.

[0010] The anti-rotation mandrel 9 is divided into a front section and a rear section in the axial direction. The front section is an external splined shaft and is in contact with the internal spline of the coupling sleeve. The rear section is an external hexagonal body and is in sliding contact with the internal hexagonal hole at the center of the front end of the rear splined shaft 2.

[0011] A spring and a spring seat are also provided in the central stepped hole at the front end of the rear spline shaft 2. The spring is located between the rear section and the spring seat, and the spring seat is connected to the rear spline shaft 2. The spring elastically pushes the front section of the anti-rotation mandrel to maintain spline connection with the coupling threaded sleeve.

[0012] The thrust applied by the spring causes the front section of the anti-rotation mandrel to insert into the internal spline of the coupling sleeve, preventing relative rotation between the coupling sleeve and the rear spline shaft and thus loosening the threaded connection between them. Furthermore, the coupling sleeve can constrain the axial position of the front spline shaft, preventing axial displacement and ensuring that the front and rear spline shafts do not become loose.

[0013] Furthermore, the rear section of the anti-rotation mandrel 9 has a central inner circular hole, and the spring seat has an axial protrusion structure, which forms a hole-shaft guide fit with the axial protrusion structure of the spring seat 3, effectively preventing abnormal displacement of the end face during the spring compression process.

[0014] Furthermore, the retaining ring consists of two semi-rings, each with chamfered ends. This facilitates installation and disassembly and avoids the stringent space requirements associated with using retaining rings. The chamfered ends of the semi-circular pad facilitate smooth insertion into the mounting slot of the front spline, preventing jamming.

[0015] Furthermore, the nut 8 has two symmetrical planes machined on its outer cylindrical surface for easy tightening with tools. The symmetrical planes do not penetrate the cylindrical surface axially, ensuring one end retains a complete cylindrical surface. This complete cylindrical surface helps to expand the two semi-circular washers 6 (forming radial limits) when the nut is fully tightened, preventing the retaining ring 6 from disengaging from the groove and thus avoiding loss of its edge-blocking function.

[0016] Furthermore, the hollow shaft at the rear end of the front spline shaft 1 and the outer flange are in clearance fit.

[0017] Furthermore, the hollow shaft at the rear end of the front spline shaft 1 is provided with an annular groove for assembling the retaining ring 6.

[0018] Furthermore, the sum of the axial length of the internal threaded hole at the center of the front end of the rear spline shaft 2 and the axial thickness of the nut is equal to the external thread length of the coupling sleeve. This ensures that after the coupling sleeve 7 is tightened with the nut, the two end faces of the nut 18 are tightly against the outer flange and the first step surface, respectively.

[0019] Furthermore, the spring seat is an adjusting screw, which is connected to the rear spline shaft. Rotating the adjusting screw can adjust the spring force.

[0020] Furthermore, the retaining ring 6, nut 8, coupling threaded sleeve 7, anti-rotation mandrel 9, spring 10, and spring seat 3 are all rotating structures.

[0021] The advantages of this invention are: while ensuring the reliability of the spline shaft connection, it reduces the difficulty of the assembly process, eliminates the need to control the tightening angle of the connecting screws, and all parts are designed as symmetrical rotating bodies to avoid adverse effects on vibration during rotor operation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 This is a schematic diagram (color model) of the center of the front end of the rear spline shaft;

[0024] Figure 3 This is a schematic diagram (black and white line drawing) of the center of the front end of the rear spline shaft;

[0025] Figure 4 This is a schematic diagram of the structure of the coupling threaded sleeve;

[0026] Figure 5 This is a schematic diagram of the anti-rotation mandrel;

[0027] Figure 6 This is a schematic diagram of the anti-rotation mandrel;

[0028] Figure 7 This is a schematic diagram of the nut's structure;

[0029] Figure 8 This is a structural diagram of the rear end of the front spline shaft;

[0030] Figure 9 This is a schematic diagram of the structure of a half-ring of a retaining circlip;

[0031] Wherein: 1-front splined shaft, 2-rear splined shaft, 3-spring seat, 4-first stepped surface, 5-internal hexagonal hole, 6-circlip, 7-coupling threaded sleeve, 8-nut, 9-anti-rotation mandrel, 10-spring, 11-internal threaded hole. Detailed Implementation

[0032] The disclosed examples will be described more fully with reference to the accompanying drawings, in which some (but not all) of the disclosed examples are shown. In fact, many different examples may be described, and these examples should not be construed as limited to those set forth herein. Rather, these examples are described so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0033] A structure for preventing the splined shafts from coming loose after mating is provided, comprising a front splined shaft 1, a rear splined shaft 2, a retaining ring 6, a nut 8, a coupling threaded sleeve 7, an anti-rotation mandrel 9, a spring 10, and a spring seat 3;

[0034] The rear end of the front spline shaft 1 is a hollow shaft structure with external splines, and the center of the front end of the rear spline shaft 2 is a three-step hole. The stepped hole consists of an internal spline hole, an internal threaded hole 11, and an internal hexagonal hole 5 from the outside to the inside. The external spline at the rear end of the front spline shaft 1 and the internal spline hole at the front end of the rear spline shaft 2 are connected by a spline. The first step surface is between the internal spline hole and the internal threaded hole.

[0035] The coupling sleeve is a hollow shaft with an internal spline inside and an external thread outside. One end of the coupling sleeve forms an outward flange, and the outer diameter of the outward flange is larger than the inner diameter of the retaining ring 6. The retaining ring 6 is installed in the hollow shaft structure at the rear end of the front spline shaft 1.

[0036] The outer flange of the coupling sleeve is located inside the hollow shaft structure at the rear end of the front spline shaft 1, and is axially limited by the retaining ring and cannot move axially. The external thread of the coupling sleeve is threadedly connected to the internal threaded hole at the center of the front end of the rear spline shaft 2. The nut is threadedly engaged with the external thread of the coupling sleeve, and the nut is limited between the outer flange and the first stepped surface 4. The nut also radially limits the retaining ring.

[0037] The anti-rotation mandrel 9 is divided into a front section and a rear section in the axial direction. The front section is an external splined shaft and is in contact with the internal spline of the coupling sleeve. The rear section is an external hexagonal body and is in sliding contact with the internal hexagonal hole at the center of the front end of the rear splined shaft 2.

[0038] A spring and a spring seat are also provided in the central stepped hole at the front end of the rear spline shaft 2. The spring is located between the rear section and the spring seat, and the spring seat is connected to the rear spline shaft 2. The spring elastically pushes the front section of the anti-rotation mandrel to maintain spline connection with the coupling threaded sleeve.

[0039] The thrust applied by the spring causes the front section of the anti-rotation mandrel to insert into the internal spline of the coupling sleeve, preventing relative rotation between the coupling sleeve and the rear spline shaft and thus loosening the threaded connection between them. Furthermore, the coupling sleeve can constrain the axial position of the front spline shaft, preventing axial displacement and ensuring that the front and rear spline shafts do not become loose.

[0040] The rear section of the anti-rotation mandrel 9 has a central inner circular hole, and the spring seat has an axial protrusion structure, which forms a hole-shaft guide fit with the axial protrusion structure of the spring seat 3, effectively preventing abnormal displacement of the end face during the spring compression process.

[0041] The retaining ring consists of two semi-rings, each with chamfered ends. This facilitates installation and disassembly and avoids the stringent space requirements associated with using retaining rings. The chamfered ends of the semi-circular pad ensure smooth insertion into the mounting slot of the front spline, preventing jamming.

[0042] Nut 8 has two symmetrical planes machined on its outer cylindrical surface for easy tightening with tools. The symmetrical planes do not penetrate the cylindrical surface axially, leaving one end with a complete cylindrical surface. The complete cylindrical surface helps to expand the two semi-circular washers 6 when the nut is fully tightened (forming a radial limit), preventing the retaining ring 6 from disengaging from the retaining groove and thus avoiding the loss of its edge-blocking function.

[0043] The hollow shaft at the rear end of the front spline shaft 1 has a clearance fit with the outer flange.

[0044] The hollow shaft at the rear end of the front spline shaft 1 has an annular groove for assembling the retaining ring 6.

[0045] The sum of the axial length of the internal threaded hole at the center of the front end of the rear splined shaft 2 and the axial thickness of the nut is equal to the external thread length of the coupling sleeve. Ensure that after the coupling sleeve 7 is tightened with the nut, the two end faces of the nut 18 are in close contact with the outer flange and the first step surface, respectively.

[0046] Descriptions of various advantageous arrangements have been shown for illustrative and descriptive purposes, but such descriptions are not intended to be exclusive or limited to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. Furthermore, different advantageous examples may describe different advantages compared to other advantageous examples. One or more examples have been selected and described in order to best illustrate the principles and practical application of the examples, and to enable those skilled in the art to understand that this disclosure contains various examples with various modifications suitable for the particular intended use.

Claims

1. A structure for preventing a spline shaft from being detached after butt joint, characterized in that: It includes a front splined shaft (1), a rear splined shaft (2), a retaining ring (6), a nut (8), a coupling threaded sleeve (7), an anti-rotation mandrel (9), a spring (10), and a spring seat (3); The rear end of the front spline shaft (1) is a hollow shaft structure with external splines, and the center of the front end of the rear spline shaft (2) is a three-step hole. The step hole is an internal spline hole, an internal thread hole and an internal hexagonal hole from the outside to the inside. The external spline at the rear end of the front spline shaft (1) and the internal spline hole at the front end of the rear spline shaft (2) are splined. The first step surface is between the internal spline hole and the internal thread hole. The coupling sleeve is a hollow shaft with an internal spline inside and an external thread outside. One end of the coupling sleeve forms an outward flange, and the outer diameter of the outward flange is larger than the inner diameter of the retaining ring (6). The retaining ring (6) is installed in the hollow shaft structure at the rear end of the front spline shaft (1). The outer flange of the coupling sleeve is located inside the hollow shaft structure at the rear end of the front spline shaft (1) and is axially limited by the retaining ring and cannot move axially. The external thread of the coupling sleeve is threadedly connected to the internal thread hole at the center of the front end of the rear spline shaft (2). The nut is threadedly engaged with the external thread of the coupling sleeve, and the nut is limited between the outer flange and the first stepped surface. The nut also radially limits the retaining ring. The anti-rotation mandrel (9) is divided into a front section and a rear section in the axial direction. The front section is an external spline shaft and is in contact with the internal spline of the coupling sleeve. The rear section is an external hexagonal body and is in sliding contact with the internal hexagonal hole at the center of the front end of the rear spline shaft (2). A spring and a spring seat are also provided in the central stepped hole at the front end of the rear spline shaft (2). The spring is located between the rear section and the spring seat, and the spring seat is connected to the rear spline shaft. The spring elastically pushes the front section of the anti-rotation mandrel to maintain spline connection with the coupling threaded sleeve.

2. The anti-disengagement structure of a spline shaft after butt joint according to claim 1, characterized in that: The rear section of the anti-rotation mandrel (9) has a central inner circular hole. The spring seat has an axial protrusion structure, which forms a hole-shaft guide fit with the axial protrusion structure of the spring seat (3), effectively preventing abnormal displacement of the end face during the spring compression process.

3. The anti-disengagement structure of a spline shaft after butt joint according to claim 1, characterized in that: The retaining ring consists of two semi-rings, each with chamfered ends.

4. The anti-disengagement structure of a spline shaft after butt joint according to claim 1, characterized in that: The nut has two symmetrical planes machined on its outer cylindrical surface to facilitate tightening with tools.

5. The anti-disengagement structure of a spline shaft after butt joint according to claim 1, characterized in that: The hollow shaft at the rear end of the front spline shaft and the outer flange are in clearance fit.

6. The anti-disengagement structure of a spline shaft after butt joint according to claim 1, characterized in that: The hollow shaft at the rear end of the front spline shaft 15 is provided with an annular groove for assembling a retaining ring (6).

7. The anti-detachment structure after spline shaft docking as described in claim 1, characterized in that: The sum of the axial length of the internal threaded hole at the center of the front end of the rear spline shaft and the axial thickness of the nut is equal to the external thread length of the coupling sleeve.

8. The anti-disengagement structure of a spline shaft after butt joint according to claim 1, characterized in that: The spring seat is an adjusting screw, which is connected to the rear spline shaft. Rotating the adjusting screw can adjust the spring force.

9. The anti-disengagement structure of a spline shaft after butt joint according to claim 1, characterized in that: The retaining ring, nut, coupling threaded sleeve, anti-rotation mandrel, spring, and spring seat are all rotating structures.

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