A gearbox planet carrier assembly

Abstract

The utility model discloses a kind of gearbox planetary carrier assemblies, it is related to planetary carrier field, the utility model includes planetary carrier, the middle position of planetary carrier is equipped with spline shaft, the outer wall of spline shaft is equipped with multiple spline teeth, and the outer wall of spline tooth and spline shaft is coated with wear-resistant coating, and spline tooth presents slightly thicker in the middle, the shape of two ends gradually thin along length direction.This utility model is designed by the spline tooth along length direction presents slightly thicker in the middle, the drum shape shape of two ends gradually thin, can compensate assembly error or the trace deformation of shaft, make tooth surface contact area maximization when engaging, load is evenly distributed along tooth length, avoid local stress concentration, and the risk of root fracture is reduced, and then prolong its service life.

Description

Technical Field

[0001] This utility model relates to the field of planetary carriers, specifically a planetary carrier assembly for a gearbox. Background Technology

[0002] The planetary carrier of the transmission is one of the most critical components of the planetary gear mechanism in a hydraulic automatic transmission. It is not a simple gear, but a composite support frame that supports, connects, and enables the planetary gears to revolve around its axis. It integrates multiple planetary gears into a cooperating whole and is a key basic structure for realizing power transmission, speed change, and torque conversion.

[0003] Existing planetary carriers for transmissions typically have a splined shaft with splined teeth. However, the splined teeth of planetary carriers are mostly straight. Due to the localized stress concentration of straight splined teeth, the tooth root, as a weak stress area, is prone to fatigue cracks under high-frequency meshing and alternating loads (such as torque fluctuations during gear shifting), eventually leading to tooth root fracture. After the splined teeth fracture, the planetary carrier cannot transmit torque normally, directly causing transmission failure. The vehicle may experience power interruption, gear shifting sticking, and other malfunctions. Utility Model Content

[0004] Based on this, the purpose of this utility model is to provide a planetary carrier assembly for a gearbox, in order to solve the technical problem that the spline teeth on the existing spline shaft are generally straight spline teeth, and that the local stress concentration of straight spline teeth and the root of the tooth as a weak stress area are prone to fatigue cracks.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a gearbox planetary carrier assembly, including a planetary carrier, a splined shaft is installed at the middle position of the planetary carrier, a plurality of splined teeth are installed on the outer wall of the splined shaft, and the splined teeth and the outer wall of the splined shaft are coated with a wear-resistant coating, and the splined teeth have a shape that is slightly thicker in the middle and gradually thinner at both ends along the length direction.

[0006] By adopting the above technical solution, the planetary carrier supports components such as the splined shaft, splined teeth, and planetary gears in the gearbox, and transmits the overall torque.

[0007] Furthermore, the multiple spline teeth are distributed in a ring array on the outer wall of the spline shaft.

[0008] By adopting the above technical solutions, it is ensured that the torque is transmitted evenly and local overload is avoided.

[0009] Furthermore, the wear-resistant coating is a diamond-like carbon coating.

[0010] By adopting the above technical solutions, diamond-like carbon coatings (hardness ≥1000HV) reduce abrasive wear and adhesive wear.

[0011] Furthermore, the planetary carrier is provided with multiple connection holes.

[0012] By adopting the above technical solution, the planetary carrier is fixed to the external components through the connecting holes, ensuring the coaxiality of the transmission.

[0013] Furthermore, the planetary carrier is made of alloy steel (such as 40Cr or 20CrMnTi).

[0014] By adopting the above technical solutions, the gearbox can withstand heavy loads and alternating loads, avoid fatigue deformation, and thus improve the service life of the planetary carrier.

[0015] Furthermore, the spline shaft and spline teeth are integrally formed.

[0016] By adopting the above technical solution, the spline shaft and spline teeth are integrally formed, which can eliminate gaps, adapt to high-frequency meshing conditions, and avoid power transmission lag.

[0017] Furthermore, both the spline shaft and the spline teeth are made of alloy steel (such as 40Cr or 20CrMnTi).

[0018] By adopting the above technical solutions, the shear and bending strength of the spline teeth can be enhanced to meet the requirements of high torque transmission.

[0019] Furthermore, the splined shaft has an internal shaft hole.

[0020] By adopting the above technical solutions, the weight of the spline shaft is reduced, the moment of inertia is decreased, and the transmission response speed is improved.

[0021] Furthermore, the thickness of the wear-resistant coating ranges from 1.5 to 5 μm.

[0022] By adopting the above technical solution, a thickness of 1.5-5μm is suitable for high-frequency meshing, avoiding coating peeling and extending the service life of the components.

[0023] In summary, the present invention has the following main advantages: 1. This utility model features a drum-shaped design where the spline teeth are slightly thicker in the middle and gradually thinner at both ends along the length direction. This design can compensate for assembly errors or slight deformation of the shaft, maximize the contact area of ​​the tooth surface during meshing, distribute the load evenly along the tooth length, avoid local stress concentration, and reduce the risk of tooth root fracture, thereby extending its service life. 2. This utility model can reduce meshing wear and lower the coefficient of friction by applying a wear-resistant coating (diamond-like coating with a thickness of 1.5-5μm) to the outer wall of the spline shaft and spline teeth, thereby improving the wear resistance and service life of the spline shaft and spline teeth. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention; Figure 2 This is a top view of the overall structure of this utility model; Figure 3 This is a schematic diagram of the cross-sectional structure of the spline shaft of this utility model; Figure 4 For the present utility model Figure 2 A magnified structural diagram of point A in the middle.

[0025] In the diagram: 1. Planetary carrier; 2. Splined shaft; 3. Connecting hole; 4. Shaft hole; 5. Spline teeth; 6. Wear-resistant coating. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] The embodiments of this utility model will be described below based on its overall structure.

[0028] Example 1: A planetary carrier assembly for a gearbox, such as Figures 1-4 As shown, the system includes a planetary carrier 1, a splined shaft 2 installed at the middle position of the planetary carrier 1, and multiple splined teeth 5 installed on the outer wall of the splined shaft 2. The splined teeth 5 and the outer wall of the splined shaft 2 are coated with a wear-resistant coating 6. The splined teeth 5 have a shape that is slightly thicker in the middle and gradually thins at both ends along the length direction. The planetary carrier 1 carries the splined shaft 2, the splined teeth 5 and the planetary gears in the gearbox, and transmits the overall torque. The multiple splined teeth 5 are distributed in a ring array on the outer wall of the splined shaft 2 to ensure that the force is evenly distributed during torque transmission and to avoid local overload.

[0029] See Figures 1-4 The planetary carrier 1 has multiple connecting holes 3, which are used to fix the planetary carrier 1 to external components and ensure the coaxiality of the transmission. The planetary carrier 1 is made of alloy steel (such as 40Cr or 20CrMnTi), which can withstand the heavy load and alternating load of the gearbox, avoid fatigue deformation, and thus improve the service life of the planetary carrier 1. The spline shaft 2 and the spline teeth 5 are integrally formed, which can eliminate the gap, adapt to high-frequency meshing conditions, and avoid power transmission lag. The spline shaft 2 has a shaft hole 4 inside, which reduces the weight of the spline shaft 2, reduces the moment of inertia, and improves the transmission response speed.

[0030] Example 2: Based on the above embodiment 1, in order to improve the bending resistance of the spline shaft 2 and spline teeth 5, the following materials will be used to make the spline shaft 2 and spline teeth 5.

[0031] Specifically, both the spline shaft 2 and the spline teeth 5 are made of alloy steel (such as 40Cr or 20CrMnTi) to enhance the shear and bending strength of the spline teeth 5 and meet the requirements of high torque transmission.

[0032] Example 3: Based on the above embodiment 1, in order to improve the performance of the wear-resistant coating 6, the following materials will be used to make the wear-resistant coating 6.

[0033] Specifically, the wear-resistant coating 6 is a diamond-like carbon (DLC) coating. The DLC coating (hardness ≥ 1000 HV) reduces abrasive wear and adhesive wear. The thickness of the wear-resistant coating 6 is between 1.5-5 μm. The 1.5-5 μm thickness is suitable for high-frequency meshing, prevents the coating from falling off, and extends the service life of the component.

[0034] The working principle of this utility model is as follows: First, the planetary carrier 1 is fixed to the gearbox housing or support component with bolts through the connecting holes 3 on the planetary carrier 1, limiting its radial / axial displacement and ensuring the coaxiality of the overall structure (error ≤ 0.05mm), providing a stable foundation for transmission; the power of the gearbox is input through the internal spline component (such as the drive shaft hub) that meshes with the spline shaft 2. The spline shaft 2 and the spline teeth 5 are integrally formed, and the torque is evenly transmitted to the spline shaft 2 through the meshing surface of the spline teeth 5, and then transmitted to the planetary carrier 1 by the spline shaft 2, which finally drives the planetary gears and other components in the gearbox to achieve power output; The drum-shaped design of spline tooth 5, which is thick in the middle and thin at both ends, can compensate for assembly errors or slight deformation of the shaft, maximize the contact area of ​​the tooth surface during meshing, distribute the load evenly along the tooth length, and avoid local stress concentration. The diamond-like coating on the outer wall of spline shaft 2 and spline tooth 5 can reduce meshing wear and lower the coefficient of friction.

[0035] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the present invention and are not intended to limit the invention. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the present invention, provided that such modifications, substitutions, and variations are within the scope of the claims of the present invention and are protected by patent law.

Claims

1. A gearbox planetary carrier assembly, comprising a planetary carrier (1), characterized in that: A spline shaft (2) is installed at the middle position of the planetary carrier (1). Multiple spline teeth (5) are installed on the outer wall of the spline shaft (2). The spline teeth (5) and the outer wall of the spline shaft (2) are coated with a wear-resistant coating (6). The spline teeth (5) are slightly thicker in the middle and gradually thinner at both ends along the length direction.

2. The gearbox planetary carrier assembly according to claim 1, characterized in that: Multiple spline teeth (5) are arranged in a ring array on the outer wall of the spline shaft (2).

3. A gearbox planetary carrier assembly according to claim 1, characterized in that: The wear-resistant coating (6) is a diamond-like coating.

4. A gearbox planetary carrier assembly according to claim 1, characterized in that: The planetary carrier (1) has multiple connection holes (3).

5. A gearbox planetary carrier assembly according to claim 1, characterized in that: The planetary carrier (1) is made of alloy steel.

6. A gearbox planetary carrier assembly according to claim 1, characterized in that: The spline shaft (2) and spline teeth (5) are integrally formed.

7. A gearbox planetary carrier assembly according to claim 1, characterized in that: Both the spline shaft (2) and the spline teeth (5) are made of alloy steel.

8. A gearbox planetary carrier assembly according to claim 1, characterized in that: The spline shaft (2) has a shaft hole (4) inside.

9. A gearbox planetary carrier assembly according to claim 1, characterized in that: The thickness of the wear-resistant coating (6) is between 1.5 and 5 μm.

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