Planetary gear carrier

Abstract

The present application belongs to the technical field of planetary gear transmission mechanism parts, and particularly relates to a planetary gear carrier, which comprises a front planetary carrier body and a rear planetary carrier body arranged in two parts, and a connecting column is arranged on the front planetary carrier body, the coaxial bidirectional transmission structure effectively increases the meshing length and the bearing area, the load is uniformly distributed, and the transmission stiffness and stability are significantly improved; the radial inner and outer double-side island-shaped reinforcing structure is adopted on the two sides of the groove in the circumferential direction, the stress concentration area is precisely reinforced, and the connection strength and the fatigue resistance of the brazing position are greatly improved; the through dynamic balance hole group realizes overall double-face dynamic balance, overcomes the technical prejudice in the industry that low speed does not need dynamic balance, and obviously reduces the vibration, noise and gear impact; the flow guide structure and the labyrinth type fitting structure improve the flow and filling effect of the brazing filler metal, and improve the uniformity and reliability of the weld; the heat dissipation gap improves the heat dissipation capacity, reduces the structural stress under high temperature working conditions, and prolongs the overall service life.

Description

Technical Field

[0001] This invention belongs to the technical field of planetary gear transmission mechanism components, specifically relating to a planetary gear carrier. Background Technology

[0002] Planetary gear carriers are core load-bearing and transmission components in planetary reduction mechanisms, automotive automatic transmissions, and engineering machinery transmission devices. Their structural strength, connection reliability, and transmission smoothness directly determine the transmission accuracy, operating noise level, and service life of the entire transmission system. They are essential for reducing the machining costs of complex structures, improving material utilization, and increasing mass production efficiency.

[0003] Existing technologies generally employ a split planetary gear carrier structure, dividing the overall structure into two parts: a front planetary carrier and a rear planetary carrier. Assembly and positioning are achieved through the mating of connecting posts on the front planetary carrier and corresponding grooves on the rear planetary carrier. Brazing filler metal is injected through brazing holes in the grooves, and the two parts are then bonded together as a single structure through a sintering brazing process. However, this type of split planetary gear carrier still has many shortcomings in practical applications. Its transmission interface often uses a single-sided internal spline or single-sided external gear structure, resulting in limited meshing length and concentrated stress. Under frequent start-stop and impact load conditions, it is prone to excessive meshing stress and insufficient transmission stability. At the same time, the mating area between the connecting post and the groove is a weak point in the structure. The stress concentration at the edge of the groove is significant, making the weld prone to cracking and local fracture under torsional and alternating impact loads. Furthermore, the uniformity of brazing filler metal flow is poor during brazing, leading to localized incomplete welds and missed welds. The weld density is insufficient, and the connection strength is difficult to meet the requirements of heavy-duty operation. In addition, there is a common industry bias that planetary carriers do not need dynamic balancing structures under low-speed conditions. The lack of a double-sided dynamic balancing structure adapted to the split structure results in inertial impacts from frequent starts and stops, which can easily cause vibration and increased noise, exacerbating gear meshing wear. At the same time, the existing structure has insufficient heat dissipation performance, which can easily lead to stress accumulation under high-temperature conditions, further reducing the reliability and service life of the structure. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a planetary gear carrier with reasonable structural design, high connection strength, smooth transmission, excellent dynamic balance performance, and suitable for powder metallurgy and sintering brazing processes.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A planetary gear carrier includes a front planetary carrier body and a rear planetary carrier body that are separately arranged. A connecting post is provided on the front planetary carrier body, and a groove corresponding to the connecting post is provided on the rear planetary carrier body. A brazing hole is provided at the groove. The front planetary carrier body and the rear planetary carrier body are fixed together by sintering and brazing.

[0007] The core improvement of this invention lies in:

[0008] It adopts a coaxial bidirectional transmission structure, with a coaxial external transmission component on the front planetary carrier body and a coaxial internal transmission component on the rear planetary carrier body, so that the two ends mesh and transmit simultaneously, resulting in more uniform force distribution and higher rigidity.

[0009] Island-shaped reinforcement structures are arranged radially on both sides of each groove to reinforce the weakest groove edge, significantly reducing stress concentration and improving torsional and impact resistance.

[0010] A dynamic balancing hole assembly is installed that runs through the front and rear planetary carrier bodies to achieve true double-sided dynamic balancing and suppress vibration and impact caused by frequent starts and stops.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] The coaxial bidirectional transmission structure effectively increases the meshing length and bearing area, resulting in uniform load distribution and significantly improved transmission stiffness and stability. The radially inner and outer double-sided island-shaped reinforcement structure on both sides of the groove precisely reinforces stress concentration areas, greatly enhancing the connection strength and fatigue resistance of the brazed joints. The through-type dynamic balancing hole group achieves overall double-sided dynamic balancing, overcoming the industry's technical bias that low-speed operation does not require dynamic balancing, and significantly reducing vibration, noise, and gear impact. The flow-guiding structure and labyrinth-type interlocking structure improve the flow and filling effect of the brazing filler metal, increasing weld uniformity and reliability. The heat dissipation notch enhances heat dissipation capacity, reduces structural stress under high-temperature conditions, and extends overall service life. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0014] Figure 1 This is a schematic diagram of the overall side view structure of the present invention;

[0015] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0016] Figure 3 This is a schematic diagram of the rear planetary carrier body structure of the present invention;

[0017] Figure 4 This is a schematic diagram of the front planetary carrier body structure of the present invention.

[0018] In the diagram: 1. Front planetary carrier body; 11. External transmission component; 2. Rear planetary carrier body; 22. Internal transmission component; 21. Connecting column; 23. Fitting groove; 31. Groove; 32. Flow guiding structure; 33. Positioning rib; 41. Brazing hole; 5. Dynamic balancing hole group; 51. Balancing hole; 52. Counterweight plug; 61. Island-shaped reinforcement structure; 61a. Inner reinforcing boss; 61b. Outer reinforcing boss; 7. Heat dissipation notch. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1

[0021] This invention discloses a planetary gear carrier, which adopts a split powder metallurgy sintering and brazing structure, mainly comprising two parts: a front planetary carrier body 1 and a rear planetary carrier body 2.

[0022] Furthermore, the front planetary carrier body 1 has multiple connecting columns 21 integrally formed on the side facing the rear planetary carrier body 2. The connecting columns 21 are evenly distributed circumferentially, and the column structure has sufficient bending and torsional strength.

[0023] Furthermore, the front end face of the rear planetary carrier body 2 is provided with grooves 31 that correspond one-to-one with the number, position and shape of the connecting columns 21. The connecting columns 21 and the grooves 31 are fitted with clearance. During assembly, the connecting columns 21 are inserted into the grooves 31 to achieve axial and circumferential positioning.

[0024] Furthermore, each groove 31 has a brazing hole 41 at its bottom or wall position. The brazing hole 41 is a through hole that penetrates the rear planetary carrier body 2. In the sintering brazing process, liquid brazing filler metal flows into the fitting gap between the connecting post 21 and the groove 31 through the brazing hole 41. After cooling, it forms a metallurgical bond, so that the front planetary carrier body 1 and the rear planetary carrier body 2 are firmly connected as a whole.

[0025] Example 2

[0026] Furthermore, a coaxial external transmission component 11 is integrally provided at the front center of the front planetary carrier body 1. The external transmission component 11 is an external spline or an external gear, used for external meshing transmission with an external transmission shaft or gear mechanism.

[0027] Furthermore, at the rear center of the planetary carrier body 2, a coaxial internal transmission component 22 is integrally provided. The internal transmission component 22 is an internal spline or an internal gear, used for internal meshing transmission with an external transmission shaft or gear mechanism.

[0028] Furthermore, the external transmission component 11 and the internal transmission component 22 are arranged strictly coaxially to form a coaxial bidirectional transmission structure.

[0029] Furthermore, in the working state, the torque can be input from the front external transmission component 11 and output from the rear internal transmission component 22, or it can be input from the rear internal transmission component 22 and output from the front external transmission component 11, so that both ends participate in the meshing transmission at the same time, effectively increasing the meshing length and bearing area, making the load evenly distributed along the axial and circumferential directions, and significantly improving the transmission stiffness and stability.

[0030] Furthermore, depending on different transmission requirements, the tooth profiles of the external transmission component 11 and the internal transmission component 22 can be straight teeth, helical gears, or involute teeth to adapt to different speed, load, and noise requirements.

[0031] Example 3

[0032] Furthermore, on the front end face of the rear planetary carrier body 2, each groove 31 is provided with an island-shaped reinforcing structure 61 on both sides along the circumferential direction.

[0033] Furthermore, the island-shaped reinforcing structure 61 is arranged radially along the planetary carrier on both inner and outer sides, specifically including:

[0034] An inner reinforcing boss 61a is located radially inside the groove 31, near the center of the planet carrier;

[0035] The outer reinforcing boss 61b is located radially outside the groove 31, near the outer edge of the planet carrier.

[0036] Furthermore, the island-shaped reinforcing structure 61 is an independent block protrusion, which is integrally formed with the rear planetary carrier body 2. It does not extend into the groove 31, does not contact the connecting post 21, and does not affect the assembly positioning and brazing filler flow of the connecting post 21.

[0037] Furthermore, to avoid stress concentration at sharp corners, the roots of both the inner reinforcing boss 61a and the outer reinforcing boss 61b are provided with smooth transition rounded corners to make the stress distribution more uniform.

[0038] Furthermore, when the planetary carrier is subjected to torsional and impact loads, the edge of the groove 31 is the area of ​​maximum stress. The island-shaped reinforcing structure 61 directly thickens and strengthens this weak area locally, which greatly improves the structure's resistance to torsion, impact and fatigue cracking, and fundamentally solves the problem of easy cracking in the groove part in the prior art.

[0039] Example 4

[0040] Furthermore, a through-type dynamic balancing hole group 5 is provided on the front planetary carrier body 1 and the rear planetary carrier body 2. The dynamic balancing hole group 5 includes at least one set of balancing holes 51. The balancing holes 51 are arranged along the axial direction of the planetary carrier and pass through the front planetary carrier body 1 and the rear planetary carrier body 2 to form an integrated dynamic balancing structure that is connected from front to back.

[0041] Furthermore, in a preferred embodiment, the dynamic balancing hole group 5 includes multiple groups of balancing holes 51 evenly distributed along the circumference. The balancing holes 51 are arranged in the non-stressed area between adjacent grooves 31, without damaging the core load-bearing parts such as the connecting column 21, the groove 31, and the island-shaped reinforcing structure 61.

[0042] Furthermore, to achieve high-precision dynamic balance adjustment, a detachable counterweight plug 52 can be installed in the balance hole 51. The counterweight plug 52 and the balance hole 51 adopt an interference fit or a threaded fit. By increasing or decreasing the number of counterweight plugs 52 or replacing the counterweight plugs 52 with different masses, the overall dynamic balance of the planetary carrier can be precisely adjusted, effectively suppressing the vibration, impact and noise caused by frequent start and stop.

[0043] Example 5

[0044] Furthermore, a flow guiding structure 32 is provided on the inner wall of the groove 31. The flow guiding structure 32 is a flow guiding groove, flow guiding slope or spiral flow guiding pattern opened on the inner wall of the groove 31, and is arranged adjacent to the brazing hole 41.

[0045] Furthermore, during the sintering brazing process, liquid brazing filler metal flows from the brazing hole 41 into the groove 31. Under the guidance of the flow guiding structure 32, it evenly and quickly fills the entire mating gap between the connecting post 21 and the groove 31, avoiding local accumulation, material shortage, incomplete welding or missed welding, improving the uniformity and density of the weld, and enhancing the overall connection strength and reliability.

[0046] Furthermore, the flow guiding structure 32 is a concave structure on the inner wall of the groove, which does not protrude from the inner wall surface and does not affect the normal insertion and positioning of the connecting post 21.

[0047] Example 6

[0048] Furthermore, an annular or arc-shaped fitting groove 23 is provided on the outer wall section of the connecting column 21 inserted into the groove 31.

[0049] Furthermore, annular or arc-shaped positioning ribs 33 corresponding to the shape and position of the fitting groove 23 are provided on the inner wall of the groove 31.

[0050] Furthermore, during assembly, the positioning rib 33 engages with the fitting groove 23, forming a labyrinthine mating structure with interlocking concave and convex parts.

[0051] Furthermore, during the brazing process, the brazing filler metal fills the gap between the fitting groove 23 and the positioning rib 33, and after cooling, it forms a labyrinth-type brazing sealing structure. This structure improves the assembly positioning accuracy and coaxiality on the one hand, and significantly increases the brazing bonding area on the other hand, improving the connection strength and resistance to pull-out, while also having a certain sealing and vibration reduction effect.

[0052] Example 7

[0053] Furthermore, on the front end face of the rear planetary carrier body 2, heat dissipation notches 7 are respectively provided in the area between two adjacent grooves 31.

[0054] Furthermore, the heat dissipation notch 7 extends radially along the planetary carrier and penetrates the mating surface between the front planetary carrier body 1 and the rear planetary carrier body 2, forming a heat dissipation channel that is open at both ends.

[0055] Furthermore, during the rotation of the planetary carrier, airflow can quickly pass through the interior of the planetary carrier through the heat dissipation gap 7, carrying away the heat generated by the gear meshing and brazing parts, reducing the working temperature, reducing the thermal stress and structural deformation caused by high temperature, and achieving a certain degree of weight reduction, reducing rotational inertia. The heat dissipation gap 7 avoids key structures such as the connecting column 21, the island-shaped reinforcing structure 61, and the balance hole 51, so as not to affect the overall strength and assembly relationship.

[0056] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A planetary gear carrier, comprising a front planetary carrier body (1) and a rear planetary carrier body (2) separately disposed, wherein a connecting post (21) is provided on the front planetary carrier body (1), and a groove (31) corresponding to the connecting post (21) is provided on the rear planetary carrier body (2), wherein a brazing hole (41) is provided at the groove (31), and the front planetary carrier body (1) and the rear planetary carrier body (2) are fixed together by sintering brazing, characterized in that: The front planetary carrier body (1) is provided with a coaxial external transmission component (11) at its center, and the rear planetary carrier body (2) is provided with a coaxial internal transmission component (22) at its center. The external transmission component (11) and the internal transmission component (22) form a coaxial bidirectional transmission structure. Each of the grooves (31) is provided with an island-shaped reinforcing structure (61) on both sides of the circumference, and the island-shaped reinforcing structure (61) is arranged on both the inner and outer sides along the radial direction of the planet carrier. The front planetary carrier body (1) and the rear planetary carrier body (2) are provided with a through dynamic balancing hole group (5), and the dynamic balancing hole group (5) includes at least one balancing hole (51) that passes through the front planetary carrier body (1) and the rear planetary carrier body (2).

2. The planetary gear carrier according to claim 1, characterized in that: The external transmission component (11) is an external spline or an external gear, and the internal transmission component (22) is an internal spline or an internal gear, with a tooth structure of spur, helical, or involute.

3. The planetary gear carrier according to claim 1, characterized in that: The island-shaped reinforcing structure (61) includes a reinforcing boss (61a) located radially inside the groove (31) and a reinforcing boss (61b) located radially outside. The boss and the rear planetary carrier body (2) are an integral structure, and the root of the boss is provided with a smooth transition rounded corner.

4. The planetary gear carrier according to claim 1, characterized in that: The inner wall of the groove (31) is provided with a flow guiding structure (32), which is used to guide the brazing material to fill the gap between the connecting column (21) and the groove (31) evenly.

5. The planetary gear carrier according to claim 1, characterized in that: The outer wall of the connecting column (21) is provided with a fitting groove (23), and the inner wall of the groove (31) is provided with a corresponding positioning rib (33). The fitting groove (23) and the positioning rib (33) together form a labyrinth brazing sealing structure.

6. The planetary gear carrier according to claim 1, characterized in that: The dynamic balance hole group (5) includes multiple circumferentially distributed balance holes (51), and a detachable counterweight plug (52) can be installed in the balance hole (51) for precise adjustment of the dynamic balance.

7. The planetary gear carrier according to claim 1, characterized in that: A heat dissipation notch (7) is provided between two adjacent grooves (31), and the heat dissipation notch (7) passes through the mating surface of the front planetary carrier body (1) and the rear planetary carrier body (2).

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