Internal and external spline connecting device with modularized variable stiffness damping structure

Abstract

The invention discloses an internal and external spline connecting device with a modularized variable stiffness damping structure, which comprises a shaft body with external spline teeth and a hub with internal spline tooth grooves, the external spline teeth are meshed with the internal spline tooth grooves, and a modularized elastic damping mechanism is arranged between the external spline teeth and the internal spline tooth grooves. And by arranging the modularized elastic damping mechanism, a gap between the inner spline teeth and the outer spline teeth can be eliminated, and the service life of the device is greatly prolonged. In addition, the wedge-shaped block is directly integrated on the tooth surface of the external spline, an additional shell structure is omitted, the weight is lighter, integration of the torque transmission function and the vibration reduction function of the external spline is achieved, and the contradiction between vibration control and compact design of a traditional spline pair is solved. The self-adaptive variable stiffness characteristic is especially suitable for modern transmission systems with high working condition change rate, such as the fields of new energy automobiles, high-end equipment and the like, and has remarkable technical advantages and industrialization potential.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical transmission technology, and particularly relates to an inner-outer spline coupling device with a modular variable stiffness damping structure. BACKGROUND

[0002] Spline coupling is a widely used basic coupling method in mechanical equipment, which transmits torque and rotary motion through the meshing of the outer spline provided on the shaft and the inner spline provided in the hub hole. The traditional spline has the following inherent defects: 1. Gap and wear: In order to ensure assembly and relative sliding, a certain gap must exist between the inner and outer splines. Under variable load, impact or reciprocating motion conditions, the gap will gradually increase, resulting in a decrease in transmission accuracy, impact vibration and noise, and seriously affecting the service life of the equipment.

[0003] 2. Stress concentration: The spline tooth root position is a typical stress concentration area, which is prone to fatigue cracks under heavy load, resulting in fracture failure.

[0004] 3. High requirement for centering: The machining error and assembly error of the inner and outer splines are prone to cause partial wear.

[0005] 4. Difficult to maintain: Once the spline pair is worn and the gap is too large, the two core components of the shaft and the hub usually need to be replaced at the same time, resulting in high maintenance cost.

[0006] In the prior art, although the machining accuracy, surface heat treatment (such as nitriding) or elastic spline are used to improve the performance, the problems of uncontrollable gap, ineffective vibration suppression and inconvenient maintenance cannot be fundamentally solved. Therefore, an innovative spline coupling scheme is urgently needed. SUMMARY

[0007] In view of the above defects or deficiencies, the purpose of the present application is to provide an inner-outer spline coupling device with a modular variable stiffness damping structure.

[0008] To achieve the above purpose, the technical scheme of the present application is as follows: An inner-outer spline coupling device with a modular variable stiffness damping structure, comprising: a shaft body with outer spline teeth and a hub with inner spline tooth grooves, the outer spline teeth and the inner spline tooth grooves are meshed, and a modular elastic damping mechanism is arranged between the outer spline teeth and the inner spline tooth grooves.

[0009] The elastic damping mechanism comprises a modular damping bushing arranged between the outer spline teeth and the inner spline tooth grooves.

[0010] The damping bushing is a plurality of strip-shaped damping bushings, and the damping bushing is arranged on the side surface of the inner spline tooth groove.

[0011] At least one force-bearing surface of the internal spline groove is provided with a wedge-shaped groove, and the damping bushing is embedded in the wedge-shaped groove.

[0012] The damping bushing has a wedge-shaped cross-section, which is adapted to the shape of the wedge-shaped groove.

[0013] The modular damping bushing is a damping bushing made of engineering plastics or powder metallurgy materials.

[0014] An axial preload end cap is installed at the end of the hub to apply an axial force to the hub, causing the damping structure to deform radially.

[0015] The end of the hub has a mounting groove, and the axial preload end cap is fixed in the mounting groove by fastening screws.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides an internal and external spline connection device with a modular variable stiffness damping structure. By setting a modular elastic damping mechanism, the gap between the internal and external spline teeth can be eliminated, greatly extending the service life of the device. This invention also directly integrates the wedge block onto the external spline tooth surface, eliminating the need for an additional outer shell structure, resulting in a lighter weight and achieving the integration of external spline torque transmission and vibration damping functions. This resolves the contradiction between vibration control and compact design in traditional spline pairs. Its adaptive variable stiffness characteristics are particularly suitable for modern transmission systems with high operating rate variations, such as new energy vehicles and high-end equipment, demonstrating significant technical advantages and industrialization potential. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the internal and external spline connection device with a modular variable stiffness damping structure according to the present invention. Figure 2 This is a cross-sectional view of the internal and external spline connection device with a modular variable stiffness damping structure according to the present invention. Figure 3 This is a cross-sectional view of the hub with the modular variable stiffness damping structure of the present invention; Figure 4 This is a schematic diagram of the damping bushing structure in the modular variable stiffness damping structure of the present invention. Figure 5 This is a schematic diagram of the wedge-shaped groove structure in the modular variable stiffness damping structure of the present invention.

[0019] In the figure, 1—shaft; 2—external spline; 3—hub; 4—internal spline groove; 5—wedge groove; 6—damping bushing; 7—preload end cap; 8—fastening screw. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the protection scope of the present invention.

[0022] like Figures 1-3 As shown, this invention provides an internal and external spline connection device with a modular variable stiffness damping structure, comprising: a shaft 1 with external spline teeth 2 and a hub 3 with internal spline grooves 4. The external spline teeth 2 and the internal spline grooves 4 mesh with each other, and the external spline teeth 2 on the shaft 1 and the internal spline grooves 4 in the hub 3 constitute the main transmission pair. Furthermore, a modular elastic damping mechanism is provided between the external spline teeth 2 and the internal spline grooves 4.

[0023] Preferably, the elastic damping mechanism includes a modular damping bushing 6 disposed between the outer spline tooth 2 and the inner spline tooth groove 4. For example, Figure 4 As shown, the damping bushing 6 has a strip-shaped structure and is disposed on the side of the inner spline groove 4. It should be noted that, as... Figure 5 As shown, at least one force-bearing surface of the internal spline groove 4 is provided with a wedge-shaped groove 5, and the damping bushing 6 is embedded in the wedge-shaped groove 5. Exemplarily, the wedge-shaped groove 5 is formed on two force-bearing sides of each internal spline groove 4, and the damping bushing 6 has a wedge-shaped cross-section that matches the shape of the wedge-shaped groove 5, and is installed within the wedge-shaped groove 5; multiple sets of accommodating wedge-shaped grooves 5 are formed axially on the tooth-side working surface of the internal spline groove 4. Each groove contains a wedge-shaped strip, which has the following characteristics: a planar base contacting the bottom surface of the accommodating groove; and an inclined working surface contacting the side surface of the mating internal spline tooth (the inclined angle is optimized, typically 15°–30°).

[0024] This invention directly integrates the wedge block onto the external spline tooth surface, eliminating the need for an additional outer shell structure, resulting in a lighter weight. Its wedge block friction pair structure also enhances damping stability. Through the innovative combination of the wedge block and the variable curvature groove bottom, the invention achieves the integration of external spline torque transmission and vibration damping functions, resolving the contradiction between vibration control and compact design in traditional spline pairs. Its adaptive variable stiffness characteristics are particularly suitable for modern transmission systems with high operating rate variations, such as new energy vehicles and high-end equipment, demonstrating significant technological advantages and industrialization potential. The modular damping bushing material itself possesses elasticity and damping properties, effectively absorbing impact energy and suppressing vibration and noise. A preload adjustment mechanism enables "zero-backlash" transmission, and the preload can be readjusted after wear to maintain optimal meshing. When the damping bushing wears to its limit, simply loosening the preload end cap allows for easy removal of the old bushing and replacement with a new one, eliminating the need to replace the entire shaft or hub, enabling rapid and low-cost maintenance of core components. The deformation of the elastic bushing can compensate for minor alignment errors, making the load more evenly distributed on each spline tooth. At the same time, the bushing, as a "sacrificial part," avoids direct dry friction between the metal tooth surfaces, protecting the more expensive shaft 1 and hub 3.

[0025] In addition, by selecting bushing materials with different elastic moduli or designing grooves with different wedge angles, different radial stiffnesses can be achieved to meet the different working conditions from precision servo transmission to heavy engineering machinery.

[0026] To achieve the above objectives, the modular damping bushing 6 is a damping bushing made of engineering plastic or powder metallurgy material, wherein the engineering plastic is PEEK or a nylon composite material containing solid lubricant.

[0027] Furthermore, an axial preload end cap 7 is installed at the end of the hub 3, applying an axial force to the hub 3 and causing radial deformation of the damping structure. The end of the hub 3 has a mounting groove, and the axial preload end cap 7 is fixed in the mounting groove by fastening screws 8. By tightening the fastening screws 8 on the end cap 7, an axial pressure can be applied to all modular elastic damping mechanisms. Since the back of the damping bushing 6 is a wedge-shaped surface, the axial pressure is converted into radial pressure, forcing the bushing to undergo micro-elastic deformation outward (i.e., towards the external spline teeth of the shaft), thereby eliminating the initial gap with the external spline teeth side and generating a controllable preload force.

[0028] The working process of this invention is as follows: After assembly, install the axial preload end cap 7 and tighten it with the fastening screws 8. The tightening force of the screws 8 is converted into axial pressure on all bushings 6 through the end cap 7. Due to the action of the wedge-shaped surface, this axial pressure is decomposed into a radial component, pushing all bushings 6 to expand radially outward and adhere tightly to the side of the external spline teeth 2, thereby eliminating transmission backlash and providing continuous contact pressure. During transmission, torque is transmitted through the external spline teeth 2 to the damping bushings 6 on one side, and then the bushings 6 transmit the force to the hub 3. The elasticity and damping characteristics of the bushing material effectively smooth out impacts and reduce vibration and noise. When the bushings wear out after long-term use and backlash reappears, simply tightening the screws 8 again will eliminate the backlash, greatly extending the service life of the device.

[0029] It will be apparent to those skilled in the art that the above specific examples are merely preferred embodiments of the present invention. Therefore, any improvements or modifications that those skilled in the art may make to certain parts of the present invention still embody the principles of the present invention and achieve the objectives of the present invention, and all fall within the scope of protection of the present invention.

Claims

1. An internal-external spline coupling device having a modular variable stiffness damping structure, characterized by, The application relates to a shaft body (1) provided with outer spline teeth (2) and a hub (3) provided with inner spline tooth grooves (4), wherein the outer spline teeth (2) and the inner spline tooth grooves (4) are engaged, and a modular elastic damping mechanism is arranged between the outer spline teeth (2) and the inner spline tooth grooves (4). The elastic damping mechanism comprises a modular damping bushing (6) arranged between the outer spline teeth (2) and the inner spline tooth grooves (4).

2. The internal-external spline coupling device with a modular variable stiffness damping structure according to claim 1, characterized in that, The damping bushing (6) is a plurality of strip-shaped damping bushings, and the damping bushing (6) is arranged on the side of the inner spline tooth grooves (4).

3. The internal and external spline coupling device with a modular variable stiffness damping structure according to claim 2, wherein, At least one stress surface of the inner spline tooth grooves (4) is provided with a wedge-shaped groove (5), and the damping bushing (6) is embedded in the wedge-shaped groove (5).

4. The internal and external spline coupling device with a modular variable stiffness damping structure according to claim 3, wherein, The damping bushing (6) is wedge-shaped in cross section and is matched with the shape of the wedge-shaped groove (5).

5. The internal and external spline coupling device with a modular variable stiffness damping structure according to claim 4, characterized in that, The modular damping bushing (6) is made of engineering plastic or powder metallurgy material.

6. The internal and external spline coupling device with a modular variable stiffness damping structure according to claim 2 or 3, characterized in that, An axial pre-tightening end cover (7) is arranged at the end of the hub (3) to apply axial force to the hub (3) and make the damping structure radially deform.

7. The internal and external spline coupling device with a modular variable stiffness damping structure of claim 1, wherein, The end of the hub (3) is provided with a mounting groove, and the axial pre-tightening end cover (7) is fixed in the mounting groove through fastening screws (8).

8. The internal-external spline coupling device with a modular variable stiffness damping structure according to claim 7, characterized in that, ​

Images