Planet carrier with a limiting structure

Abstract

This utility model discloses a planetary carrier with a limiting structure, relating to the field of planetary gear technology. The utility model includes a planetary carrier body with two sets of mounting holes at the top and bottom. Each set of mounting holes contains a bushing, and each bushing end face is connected to a limiting plate with a lubrication groove. This utility model transforms the traditional direct interference fit between the planetary carrier mounting holes and pins into a three-layer assembly structure of mounting holes, bushings, and pins by using mounting holes and bushings. The mounting hole diameter is enlarged to accommodate the bushings, which are made of tin bronze and interference-fitted with both the mounting holes and pins. Tin bronze has lower hardness than planetary carrier steel, a lower surface friction coefficient, and better corrosion resistance. The addition of a separate limiting structure means that only the bushing needs to be replaced after wear, and the bushing experiences less wear during disassembly and assembly.

Description

Technical Field

[0001] This utility model relates to the field of planetary gear technology, specifically a planetary carrier with a limiting structure. Background Technology

[0002] Planetary gear assemblies are core components commonly used in mechanical transmissions, widely applied in automotive gearboxes, construction machinery reducers, and other equipment. They are primarily used to achieve functions such as speed reduction and torque increase, speed change and direction switching, or power splitting. A typical structure includes a sun gear, several planet gears, a ring gear, and a planet carrier. During operation, the sun gear (or ring gear, planet carrier) serves as the power input, driving the planet gears to rotate around their own axes while simultaneously revolving around the sun gear axis with the planet carrier. Power is ultimately output through the ring gear (or planet carrier, sun gear). The overall transmission efficiency is high, the structure is compact, and the load-bearing capacity is strong.

[0003] The planetary carrier is a key load-bearing and power-transmitting component of the planetary gear assembly. Its core function is to provide mounting support and motion guidance for the planetary gears. The planetary carrier typically has multiple evenly distributed mounting holes for mounting pins; the planetary gears are mounted on the pins via bearings, allowing them to rotate freely. During transmission, the planetary carrier must bear the torque transmitted by the planetary gears and transfer power to subsequent components, while ensuring that all planetary gears are always in the correct meshing position with the sun gear and ring gear. Its structural stability and strength directly affect the transmission accuracy and service life of the entire planetary gear assembly.

[0004] Currently, the maintenance of planetary gear mechanisms after long-term use requires the disassembly of planetary gears and pins. In traditional structures, the pins and planetary carrier mounting holes are mostly designed with an interference fit. During installation, the pins need to be frozen using liquid nitrogen to reduce their size before they can be installed. During disassembly, hydraulic equipment is needed to push them out. During disassembly, there is a possibility of wear between the pins and the planetary carrier mounting holes. Furthermore, if the freezing is not done properly or if there are bumps or knocks during installation, the mounting holes can also easily wear down. Among these factors, the pins are relatively inexpensive and can be directly replaced after wear. However, if the diameter of the planetary carrier mounting holes increases due to wear, the coaxiality and stability of the subsequent pin assembly will be greatly reduced, thus affecting the transmission accuracy. More importantly, as an integral structural component, the planetary carrier must be replaced as a whole once the mounting holes wear beyond the limit, resulting in high maintenance costs. Utility Model Content

[0005] Therefore, the purpose of this utility model is to provide a planetary carrier with a limiting structure to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a planetary carrier with a limiting structure, comprising a planetary carrier body, wherein two sets of mounting holes are provided at the top and bottom of the planetary carrier body, and bushings are connected inside the two sets of mounting holes, and limiting plates are connected to the end faces of the two sets of bushings, and lubrication grooves are provided on the end faces of the two sets of limiting plates.

[0007] By adopting the above technical solution, the mounting hole provides a suitable assembly space for the bushing, the bushing can isolate the direct contact between the pin and the planetary carrier body, the limiting plate can limit the axial displacement of the bushing, and the lubrication groove can supplement lubrication for key friction parts. From a structural perspective, this lays the foundation for reducing the wear of the mounting hole, improving assembly stability, and reducing transmission loss.

[0008] Furthermore, both the bushing and the limiting plate are made of tin bronze.

[0009] By adopting the above technical solution, its hardness is lower than that of the steel commonly used in planetary carriers, which can concentrate the wear during the disassembly and assembly of the pins on the bushing, avoiding direct damage to the mounting holes; at the same time, the tin bronze has a low coefficient of friction and excellent corrosion resistance, which can reduce the friction between the bushing and the pins and mounting holes, and extend the service life of the bushing and the limit plate, thus meeting the long-term use requirements of the planetary gear mechanism.

[0010] Furthermore, the diameter of the limiting plate is larger than the diameter of the mounting hole and the bushing.

[0011] By adopting the above technical solution, the limiting plate can be naturally locked on the end face of the planetary carrier body after assembly, which can effectively prevent the bushing from axially moving outward of the planetary carrier. Combined with the radial distribution of the two sets of bushings and the limiting plate, it can form a double limit with the interference fit of the bushing itself, ensuring the coaxiality of the bushing and the pin shaft assembly, and avoiding the impact of bushing displacement on the meshing accuracy of the planetary gear.

[0012] Furthermore, both the bushing and the limiting plate have beveled ends.

[0013] By adopting the above technical solution, the bevel angle can reduce the jamming between the bushing and the edge of the mounting hole during the bushing insertion process, so that the bushing can enter the assembly position smoothly and accurately; at the same time, it reduces the risk of scratches on the outer wall of the bushing or the inner wall of the mounting hole due to forced alignment during assembly, thereby improving assembly efficiency and component integrity.

[0014] Furthermore, a pin passes through the top of the bushing, and a planetary gear is sleeved on the outside of the pin. The planetary gear is rotatably connected to the pin through a bearing.

[0015] By adopting the above technical solution, the pin shaft provides a mounting carrier for the planetary gear after passing through the bushing, while the bearing reduces the rotational friction between the planetary gear and the pin shaft, so that the planetary gear can both rotate around its own axis and revolve around the sun gear axis with the planet carrier; at the same time, it ensures that the planetary gear always maintains correct meshing with the sun gear and the ring gear during the transmission process, ensuring the stability and accuracy of torque transmission.

[0016] Furthermore, the lubrication groove is double-helixed, and the two helices are connected to each other. The position of the lubrication groove corresponds to the position of the planetary gear.

[0017] By adopting the above technical solution, the double-helix structure and interconnected design can guide the lubricating oil to flow evenly and continuously to the gap between the planetary gear and the limiting plate, fully replenishing the lubricating medium during their relative motion; this can reduce the friction and wear between the planetary gear and the limiting plate, reduce the transmission loss caused by increased frictional resistance, ensure the smoothness of the planetary gear assembly transmission process, and extend the service life of related components.

[0018] Furthermore, the pin is interference-fitted with the bushing, and the bushing is interference-fitted with the mounting hole.

[0019] By adopting the above technical solution, the interference fit can ensure that there is no loose clearance between the pin, bushing, and mounting hole, avoiding the impact on accuracy due to component movement during transmission; at the same time, this fit method concentrates the wear during the disassembly and assembly of the pin on the bushing, effectively protecting the mounting hole from direct wear, reducing the risk of the mounting hole being enlarged due to wear, and reducing the probability of replacing the planetary carrier body.

[0020] Furthermore, the planetary carrier body has multiple reinforcing plates evenly distributed on its outer ring, and these reinforcing plates are located at positions corresponding to the mounting holes.

[0021] By adopting the above technical solution, the enlargement of the mounting hole diameter may lead to a decrease in the local load-bearing capacity of the planetary carrier body. However, the reinforcing plate corresponding to the mounting hole position can form a structural support in this area, enhancing the deformation resistance of the planetary carrier body. This avoids deformation around the mounting hole due to excessive force during transmission, ensuring the stability and load-bearing reliability of the overall planetary carrier structure.

[0022] Furthermore, the reinforcing plate is fixedly connected to the planetary carrier body by integral forging and turning.

[0023] By adopting the above technical solution, integral forging can eliminate the connection gap between the two, so that the reinforcing plate and the planetary carrier body form a stable integral structure, and the fatigue resistance is far superior to the separate connection method such as welding; the subsequent turning and precision machining can ensure the dimensional accuracy of the reinforcing plate, ensure that it corresponds precisely with the position of the mounting hole, continuously play the role of strength compensation, and avoid the reinforcing plate from loosening or falling off after long-term use.

[0024] Furthermore, the bushing and the limiting plate are fixedly connected by integral forging and turning.

[0025] By adopting the above technical solutions, the integral forging process eliminates weak points in the connection between the bushing and the limiting plate, enabling it to withstand axial forces during assembly and disassembly as well as radial forces during transmission, thus preventing separation. The precision machining process can strictly control key dimensions such as the outer diameter of the bushing and the diameter of the limiting plate, ensuring the compatibility between the bushing and the mounting hole, and between the limiting plate and the end face of the planetary carrier. This further guarantees the limiting effect and overall assembly accuracy, reducing the risk of functional failure due to dimensional errors.

[0026] In summary, the present invention has the following main advantages: 1. This utility model transforms the traditional direct interference fit between the planetary carrier mounting hole and the pin into a three-layer assembly structure consisting of a mounting hole, a bushing, and a pin by setting up mounting holes and bushings. The diameter of the mounting hole is enlarged to accommodate the bushing, which is made of tin bronze and interference-fitted with both the mounting hole and the pin. Tin bronze has a lower hardness than planetary carrier steel, a lower surface friction coefficient, and better corrosion resistance. This allows the wear during pin assembly and disassembly to be concentrated on the bushing, a vulnerable component, effectively reducing the risk of hole enlargement due to direct wear of the mounting hole. When the bushing wears out, only the bushing needs to be replaced to restore assembly stability, without the need to replace the entire planetary carrier, significantly reducing maintenance costs and replacement difficulty. The addition of a separate limiting structure means that only the bushing needs to be replaced after wear, and the bushing experiences less wear during assembly and disassembly. 2. This utility model, through the setting of a limiting plate, forms a T-shaped combination structure between the limiting plate and the bushing, and the diameter of the limiting plate is larger than the diameter of the mounting hole and the bushing. With the radial cooperation of the two sets of bushings at the top and bottom of the planetary carrier and the limiting plate, during the disassembly and assembly of the pin, one set of bushings can resist axial displacement through its own interference fit with the mounting hole, while the other set of bushings, through the blocking effect of the limiting plate and the interference fit, restricts axial displacement. The dual synergistic effect can significantly reduce the axial movement of the bushings, ensure the coaxiality of the bushing and the pin assembly, further improve the stability of the overall structure of the planetary carrier, and avoid the impact of bushing displacement on the meshing accuracy of the planetary gears; it also increases stability during disassembly or installation. 3. This utility model incorporates a lubrication groove designed as a double helix with the two helices connected, and the groove's position corresponds to that of the planetary gear. This structure guides the lubricating oil to flow smoothly into the gap between the planetary gear and the limiting plate, replenishing the lubricating medium during their relative motion. This effectively reduces friction and wear between the planetary gear and the limiting plate during rotation, extending the service life of both the planetary gear and the limiting plate. Simultaneously, it reduces transmission losses caused by increased frictional resistance, ensuring the smoothness of the planetary gear assembly's transmission process; reducing wear and increasing the structure's service life. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the exploded structure of this utility model; Figure 3 This is a schematic diagram of the limiting plate structure of this utility model; Figure 4 This is a schematic diagram of the bushing structure of this utility model; Figure 5 This is a schematic diagram of the installation of the bushing of this utility model; Figure 6 This is a schematic diagram showing the disassembly of the bushing of this utility model.

[0028] In the diagram: 1. Planetary carrier body; 2. Pin; 3. Planetary gear; 4. Reinforcing plate; 5. Mounting hole; 6. Bushing; 7. Limiting plate; 8. Lubrication groove. Detailed Implementation

[0029] 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.

[0030] The embodiments of this utility model will be described below based on its overall structure.

[0031] Example 1: A planetary carrier with a limiting structure, such as Figures 1-6As shown, the system includes a planetary carrier body 1. Two sets of mounting holes 5 are provided at the top and bottom of the planetary carrier body 1. Bushings 6 are connected inside each set of mounting holes 5. The pin 2 is interference-fitted with the bushing 6, and the bushing 6 is interference-fitted with the mounting hole 5. Limiting plates 7 are connected to the end faces of both sets of bushings 6. Both the bushings 6 and the limiting plates 7 are made of tin bronze. The diameter of the limiting plate 7 is larger than the diameter of the mounting hole 5 and the bushing 6. When the planetary gear 3 mechanism requires maintenance and the pin 2 is disassembled, the pin 2 is connected to the bushing 6, and the bushing 6 is connected to the mounting hole 5. All mounting holes 5 are interference fits. During disassembly, because the hardness of bushing 6 is lower than that of the planetary carrier body 1 steel, it is more susceptible to wear. Therefore, the wear will be concentrated on bushing 6, which can effectively prevent the planetary carrier mounting holes 5 from experiencing increased wear due to direct contact with the pin 2. Furthermore, during disassembly and assembly, the two sets of bushings 6 at the top and bottom of the planetary carrier and the limiting plate 7 form a double limiting effect. The set of bushings 6 in the direction of applied pressure resists axial displacement through its interference fit with the mounting holes 5, while the bushings 6 in the direction of pin 2 movement out rely on... Axial movement is limited by the blocking effect of the limiting plate 7 and its own interference fit; when the bushing 6 needs to be replaced due to long-term wear, simply remove the worn bushing 6 from the mounting hole 5 and replace it with a new bushing 6 to restore assembly stability; both the end faces of the bushing 6 and the limiting plate 7 are provided with bevels, which facilitates the guiding installation during assembly and allows the bushing 6 to be smoothly installed into the mounting hole 5; both sets of limiting plates 7 have lubrication grooves 8 on their end faces, which are double spirals with the two spirals connected to each other, providing lubrication... The position of the slide groove 8 corresponds to the position of the planetary gear 3. The double spiral lubrication groove 8 opened on the end face of the upper limit plate 7 of the planetary carrier body 1 corresponds to the position of the planetary gear 3. The lubricating oil can flow smoothly to the gap between the planetary gear 3 and the limit plate 7, continuously replenishing the lubricating medium required for the relative movement of the two. This can reduce the friction and wear between the planetary gear 3 and the limit plate 7 when the planetary gear 3 rotates, and also reduce the transmission loss caused by the increase of frictional resistance, ensuring the smoothness of the transmission process, and extending the service life of the planetary gear 3 and the limit plate 7.

[0032] See Figure 1 and Figure 2 In the above embodiment, a pin 2 passes through the top of the bushing 6, and a planetary gear 3 is sleeved on the outside of the pin 2. The planetary gear 3 is rotatably connected to the pin 2 through a bearing. When the planetary gear 3 assembly is working, the planetary carrier body 1 bears the torque transmitted by the planetary gear 3 and drives the planetary gear 3 to rotate around its own axis while revolving around the sun gear axis. During the process, the planetary gear 3 is always kept in the correct meshing position with the sun gear and the ring gear to ensure transmission accuracy.

[0033] Example 2: Based on the above embodiment 1, in order to compensate for the safety hazards caused by enlarging the size of the mounting hole 5, the following settings are now adopted.

[0034] See Figure 1 and Figure 2 In the above embodiment, multiple reinforcing plates 4 are evenly distributed on the outer ring of the planetary carrier body 1. The multiple reinforcing plates 4 are located corresponding to the mounting holes 5. The reinforcing plates 4 are fixedly connected to the planetary carrier body 1 by integral forging and turning. The multiple reinforcing plates 4 are fixed by integral forging and turning to compensate for the possible decrease in the strength of the main body after the mounting holes 5 are enlarged, so as to ensure the overall structural stability of the planetary carrier.

[0035] Example 3: Based on the above embodiment one, the following settings are now adopted to increase structural strength.

[0036] See Figures 2-6 In the above embodiments, the bushing 6 and the limiting plate 7 are fixedly connected by integral forging and turning. The bushing 6 and the limiting plate 7 are integrally formed by replacing the forging process. The connection strength is high and there are no air holes inside. The overall strength, hardness, wear resistance and other properties are far superior to those of integral casting, separate casting and welding and separate forging and welding. The subsequent turning and finishing process reduces the error.

[0037] The implementation principle of this utility model is as follows: First, in the assembly stage of the planetary carrier, the planetary carrier body 1 is used as the basic carrier. The two sets of mounting holes 5 pre-set at the top and bottom of the planetary carrier have a larger diameter than the traditional planetary carrier mounting holes 5. This design aims to provide suitable space for the assembly of the bushing 6. In the area corresponding to the mounting hole 5 on the outer ring of the planetary carrier body 1, multiple reinforcing plates 4 are fixed by integral forging and turning to compensate for the possible decrease in the main body strength after the mounting hole 5 is enlarged, ensuring the overall structural stability of the planetary carrier. Since both the bushing 6 and the limiting plate 7 are made of tin bronze, which has a lower hardness than the steel commonly used in planetary carriers, a small surface friction coefficient, and excellent corrosion resistance, and can be fixedly connected by integral forging and turning, the beveled angle set on the end face of the bushing 6 and the limiting plate 7 facilitates the guiding installation during assembly, allowing the bushing 6 to be smoothly installed into the mounting hole 5. For the installation method, please refer to [reference needed]. Figure 4 The process involves the worker placing the bushing 6 on the mounting hole 5, then placing a nylon pad with a diameter larger than that of the limiting plate 7 at the end of the limiting plate 7. The worker then passes a shaft with a diameter smaller than that of the bushing 6 through the bushing 6 or pin hole on the other side, applying force to the nylon pad by tapping or hydraulic pressure, causing the nylon pad to press the bushing 6 into the pin hole. If the bushing 6 is frozen using liquid nitrogen or other cooling methods, and assembled through cold shrinkage, the above operation is unnecessary. The bushing 6 and the mounting hole 5 form an interference fit. Because the diameter of the limiting plate 7 is larger than that of the mounting hole 5 and the bushing 6, it can naturally be locked onto the end face of the planetary carrier body 1, forming a T-shaped assembly structure, laying the foundation for subsequent limiting action. Next, after assembling the bushing 6 and the limiting plate 7, the workers first place the planetary gear 3 with the bearing inside the planetary carrier body 1. Then, the workers insert the frozen pin 2 through one end of the bushing 6, so that the pin 2 and the bushing 6 also form an interference fit. After installation, the planetary gear 3 can rotate flexibly around the pin 2. When the planetary gear 3 assembly is working, the planetary carrier body 1 bears the torque transmitted by the planetary gear 3 and drives the planetary gear 3 to rotate around its own axis while revolving around the sun gear axis. During the process, the planetary gear 3 is always kept in the correct meshing position with the sun gear and the ring gear to ensure transmission accuracy. Meanwhile, the double helical lubrication groove 8 opened on the end face of the upper limit plate 7 of the planetary carrier body 1 is positioned corresponding to the planetary gear 3. The lubricating oil can flow smoothly to the gap between the planetary gear 3 and the limit plate 7, continuously replenishing the lubricating medium required for the relative motion of the two. This can reduce the friction and wear between the planetary gear 3 and the limit plate 7 when the planetary gear 3 rotates, and also reduce the transmission loss caused by the increase of frictional resistance, ensuring the smoothness of the transmission process, and extending the service life of the planetary gear 3 and the limit plate 7. When the planetary gear 3 mechanism requires maintenance and the pin 2 is disassembled, since the pin 2 and bushing 6, and the bushing 6 and mounting hole 5 are all interference fits, during disassembly, because the bushing 6 has a lower hardness than the steel of the planetary carrier body 1, it is more susceptible to wear. Therefore, the wear will be concentrated on the bushing 6, which can effectively prevent the planetary carrier mounting hole 5 from being worn out due to direct contact with the pin 2. In addition, during disassembly and assembly, the two sets of bushings 6 at the top and bottom of the planetary carrier and the limiting plate 7 form a double limiting effect. The set of bushings 6 in the direction of applied pressure resists axial displacement through its own interference fit with the mounting hole 5, while the bushings 6 in the direction of pin 2 movement are restricted from axial movement by the blocking effect of the limiting plate 7 and their own interference fit. When the bushing 6 needs to be replaced due to long-term wear, simply remove the worn bushing 6 from the mounting hole 5 and replace it with a new bushing 6 to restore assembly stability. For disassembly methods, please refer to [link to disassembly instructions]. Figure 5 That is, the worker places a nylon pad with a diameter smaller than that of the bushing 6 at the end of the bushing 6, and then the worker applies force to the nylon pad by tapping or hydraulic pressure to remove the bushing 6 from the mounting hole 5; only the bushing 6 needs to be replaced without replacing the entire planetary carrier body 1, which greatly reduces maintenance costs and replacement difficulty.

[0038] 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 planetary carrier with a limiting structure, comprising a planetary carrier body (1), characterized in that: The planetary carrier body (1) has two sets of mounting holes (5) at the top and bottom, and each set of mounting holes (5) is connected to a bushing (6). The end faces of the two sets of bushings (6) are connected to a limiting plate (7), and the end faces of the two sets of limiting plates (7) are provided with a lubrication groove (8).

2. The planetary carrier with a limiting structure according to claim 1, characterized in that: Both the bushing (6) and the limiting plate (7) are made of tin bronze.

3. The planetary carrier with a limiting structure according to claim 2, characterized in that: The diameter of the limiting plate (7) is larger than the diameter of the mounting hole (5) and the bushing (6).

4. The planetary carrier with a limiting structure according to claim 3, characterized in that: Both the bushing (6) and the limiting plate (7) have beveled edges on their end faces.

5. The planetary carrier with a limiting structure according to claim 1, characterized in that: The top of the bushing (6) is through a pin (2), and a planetary gear (3) is sleeved on the outside of the pin (2). The planetary gear (3) is rotatably connected to the pin (2) through a bearing.

6. The planetary carrier with a limiting structure according to claim 5, characterized in that: The lubrication groove (8) is double-helixed and the two helices are connected. The position of the lubrication groove (8) corresponds to the position of the planetary gear (3).

7. The planetary carrier with a limiting structure according to claim 5, characterized in that: The pin (2) is interference-fitted with the bushing (6), and the bushing (6) is interference-fitted with the mounting hole (5).

8. The planetary carrier with a limiting structure according to claim 1, characterized in that: The planetary carrier body (1) has multiple reinforcing plates (4) evenly distributed on its outer ring, and the multiple reinforcing plates (4) are located at positions corresponding to the mounting holes (5).

9. The planetary carrier with a limiting structure according to claim 8, characterized in that: The reinforcing plate (4) is fixedly connected to the planetary carrier body (1) by integral forging and turning.

10. The planetary carrier with a limiting structure according to claim 2, characterized in that: The bushing (6) and the limiting plate (7) are fixedly connected by integral forging and turning.

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