Gearbox with single-arm planet carrier structure

Abstract

The invention discloses a gearbox of a single-arm planet carrier structure, and belongs to the technical field of gearboxes. The gearbox comprises a box body, an input shaft, at least one planetary gear set and an output shaft. The planet carrier bearing is arranged between the planet carrier and the box body to support the planet wheel set, a traditional double-arm mode is replaced with a single-arm mode, the inner surface of the box body and the outer surface of the planet carrier are subjected to surface quenching, the bearing outer ring and the bearing inner ring are formed, the structure is further simplified, the number of parts is reduced, and meanwhile the cost is reduced. The stability of the gap between the planet carrier and the box body is ensured, a traditional oil distribution ring is omitted, the structure is further simplified, the weight is reduced, the size is reduced, the production cost is reduced, and the comprehensive performance is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of gear boxes, and in particular relates to a gear box with a single-arm planetary frame structure. Background Art

[0002] A gearbox is a mechanism used to increase or decrease rotational speed. Planetary gearboxes, with their compact structure and relatively small size, maintain high performance even in space-constrained applications. Furthermore, through the transmission of multiple planetary gears, planetary gearboxes can achieve a wide range of speed ratios, meeting speed requirements under varying operating conditions. Furthermore, because the planetary gears are evenly distributed, the load is also more evenly distributed, which helps improve the gearbox's load capacity and service life. Therefore, planetary gearboxes are widely used in wind turbines.

[0003] Existing planetary gearboxes generally utilize a double-arm support structure. This configuration creates a relatively large gap between the planetary gears and the gearbox. To ensure even coverage of lubricating oil across the planetary gear surfaces and smooth flow of lubricant into the pre-defined oil system, an additional oil distribution ring is typically required at the bearing end. The primary function of this ring is to provide precise clearance control to ensure proper oil flow and distribution. Typically manufactured from copper, its inclusion not only increases production costs but also complicates the overall structure of the gearbox, making design and maintenance more difficult. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a gearbox with a single-arm planetary carrier structure to overcome the problem that the prior art requires the configuration of an oil distribution ring. The technical solution adopted by the present invention is as follows: A gearbox with a single-arm planetary carrier structure includes a housing, wherein an input shaft, at least one set of planetary gear sets and an output shaft which are sequentially connected in a transmission manner are provided in the housing; the planetary gear set includes a planetary carrier, a planetary gear shaft, planetary gears and a sun gear, the planetary gear shaft is fixed to the planetary carrier, the planetary gears are arranged on the planetary gear shaft via planetary bearings, an inner gear ring is provided in the housing at a position which matches the planetary gears, the planetary gears are meshed with the sun gear and the inner gear ring at the same time, the outer contour of the planetary carrier is surface hardened to be set as the inner ring of the bearing, the inner surface of the housing is surface hardened to be set as the outer ring of the bearing at a position which matches the outer contour of the planetary carrier, and a cylindrical rolling body is provided between the inner ring of the bearing and the outer ring of the bearing to form a planetary carrier bearing.

[0005] This solution sets an integrated planetary carrier bearing between the planetary carrier and the housing, and uses a single-arm planetary carrier to replace the commonly used double-arm planetary carrier in the industry in a smaller space. While simplifying the gearbox structure and reducing the size of the gearbox, the planetary carrier bearing structure between the planetary carrier and the housing provides sufficient support for the single-arm planetary carrier, improves the rigidity of the planetary carrier, and thus enables the gap size between the planetary carrier and the housing to always maintain good stability. The stability of the gap size means that the planetary carrier does not need an additional oil distribution ring to ensure that the oil is distributed according to the designed path. Therefore, it is equivalent to the function of the planetary carrier with a built-in oil distribution ring, thereby eliminating the copper oil distribution ring commonly used in the industry, reducing material consumption, simplifying the processing process, reducing the production and assembly workload, etc., and greatly reducing production costs.

[0006] Furthermore, the inner ring of the planetary bearing is integrally formed with the planetary gear shaft, and the outer ring of the planetary bearing is integrally formed with the planetary gear; and a rolling body is provided between the inner ring and the outer ring of the planetary bearing. This further solution integrates the inner and outer rings of the planetary bearings with the planetary axles and planetary gears. This structure eliminates the need for additional space during assembly for the inner and outer rings, making the gearbox's internal structure more compact. Furthermore, by reducing the number of components and space requirements, the gearbox's overall weight and size are reduced.

[0007] Furthermore, it includes multiple sets of planetary gear sets, and the sun gear of the upper stage is fixedly connected to the planet carrier of the lower stage; Integrating the upper sun gear and the lower planetary carrier together reduces the required axial dimensions of the gearbox. In practical applications, this reduction in axial dimensions shortens the power transmission path, reduces energy losses caused by transmission, and improves the transmission efficiency of the gearbox.

[0008] Furthermore, the planetary gear set is made of medium carbon steel, and the outer surface of the planetary shaft and the inner surface of the planetary gear are surface quenched.

[0009] Medium-carbon steel is relatively inexpensive, reducing material costs compared to case-hardened steel. The outer surface of the planetary shaft functions as the inner ring of the planetary bearing, while the inner surface of the planetary gears serves as the outer ring of the planetary bearing. Surface hardening is a heat treatment process that rapidly heats and cools the workpiece surface to achieve high hardness and wear resistance while maintaining good toughness at the core. The surface hardening process is relatively simple, with a short cycle time and low energy consumption. Surface hardening imparts excellent hardness and wear resistance to the component surface, ensuring the performance and life of the gearbox.

[0010] Furthermore, the planetary gear set includes a first-stage planetary gear set, a second-stage planetary gear set, and a third-stage planetary gear set; The first-stage planetary gear set includes a first-stage sun gear, a first-stage planetary gear, a first-stage planetary carrier, and a first-stage planetary shaft; the input shaft is fixedly connected to the first-stage planetary carrier, the first-stage sun gear is meshed with a plurality of first-stage planetary gears, and the first-stage planetary gears are simultaneously meshed with a first internal gear ring provided on the housing, and the first-stage planetary gears are rotatably provided on the first-stage planetary shaft via planetary bearings; The secondary planetary gear set includes a secondary sun gear, secondary planetary gears, a secondary planetary carrier, and a secondary planetary shaft; the primary sun gear is fixedly connected to the secondary planetary carrier, the secondary sun gear is meshed with a plurality of secondary planetary gears, the secondary planetary gears are also meshed with a second inner gear ring provided on the housing, and the secondary planetary gears are rotatably provided on the secondary planetary shaft via planetary bearings; The three-stage planetary gear set includes a three-stage sun gear, three-stage planetary gears, a three-stage planet carrier, and a three-stage planetary shaft; the second-stage sun gear is fixedly connected to the third-stage planet carrier, the third-stage sun gear is meshed with a plurality of three-stage planetary gears, and the three-stage planetary gears are also meshed with a third inner gear ring provided on the housing, and the three-stage planetary gears are rotatably provided on the three-stage planetary shaft via planetary bearings; The three-stage sun gear is fixedly connected to the final driving wheel. The box body is provided with an output shaft via a final bearing. A final bearing is provided at each end of the output shaft. An output gear is fixed on the output shaft, and the final driving wheel is engaged with the output gear.

[0011] Furthermore, the outer diameter of the final-stage driving wheel is larger than the outer diameter of the three-stage sun wheel, and the outer diameter of the output gear is smaller than the outer diameter of the final-stage driving wheel, so as to achieve speed increase.

[0012] Furthermore, the inner ring of the final-stage bearing is integrally formed with the output shaft, and the outer ring of the final-stage bearing is integrally formed with the housing.

[0013] Furthermore, the inner ring and outer ring of the final-stage bearing are processed by a surface quenching process.

[0014] Furthermore, a first radial protrusion is provided on the outer contour of the secondary planetary carrier and the tertiary planetary carrier, a second radial protrusion is provided on the box body, and the rolling body is axially arranged between the first radial protrusion and the second radial protrusion, thereby achieving a limit constraint on the axial movement of the planetary carrier.

[0015] Furthermore, an axial load-bearing bearing is provided between the planet carrier and the inner gear ring, and the load-bearing bearing is used to bear the axial displacement force of the gear box.

[0016] Furthermore, the gearbox of this solution eliminates the traditional independently arranged inner and outer rings of the planetary gear bearings, so that the planetary gears can be closer to the surface of the box body, which is conducive to heat dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic cross-sectional view of a gearbox with a single-arm planetary carrier structure according to the present invention; Figure 2 A schematic three-dimensional cross-sectional view of a gearbox having a single-arm planetary carrier structure according to the present invention; Figure 3 for Figure 1 Enlarged view of point A in the middle.

[0018] Description of the marks in the figure: 1. Housing; 2. Input shaft; 3. First inner ring gear; 4. First-stage sun gear; 5. First-stage planetary gear; 6. First-stage planet carrier; 7. First-stage planetary shaft; 8. Rolling element; 9. Second inner ring gear; 10. Second-stage sun gear; 11. Second-stage planetary gear; 12. Second-stage planet carrier; 13. Second-stage planetary shaft; 14. Third inner ring gear; 15. Third-stage sun gear; 16. Third-stage planetary gear; 17. Third-stage planet carrier; 18. Third-stage planetary shaft; 19. Final driving gear; 20. Output gear; 21. Output shaft; 22. Planet carrier bearing; 23. First radial protrusion; 24. Second radial protrusion; 25. Load-bearing bearing. DETAILED DESCRIPTION

[0019] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below with reference to the accompanying drawings.

[0020] A single-arm planetary carrier gearbox, such as Figure 1 、 Figure 2 As shown, it includes a housing 1, within which are located an input shaft 2, a three-stage planetary gear set, and an output shaft 21, which are connected in sequence. The inner and outer rings of the planetary gear bearings of each stage are integrated with the planetary gear shaft and planetary gears, respectively. The sun gear of each stage is integrated with the planetary carrier of the lower stage. The three-stage planetary gear set includes a first-stage planetary gear set, a second-stage planetary gear set, and a third-stage planetary gear set.

[0021] The primary planetary gear set includes a primary sun gear 4, multiple primary planetary gears 5, a primary planet carrier 6, and a primary planetary shaft 7. The input shaft 2 is integrally formed with the primary planetary carrier 6, to which the primary planetary shaft 7 is fixed. The primary planetary gears 5 are rotatably mounted on the primary planetary shaft 7 via planetary bearings. The primary sun gear 4 meshes with the multiple primary planetary gears 5, which in turn mesh with the first internal gear ring 3 provided on the housing 1.

[0022] The secondary planetary gearset includes a secondary sun gear 10, multiple secondary planetary gears 11, a secondary planet carrier 12, and a secondary planetary shaft 13. The primary sun gear 4 is fixedly connected to the secondary planetary carrier 12, to which the secondary planetary shaft 13 is fixed. The secondary planetary gears 11 are rotatably mounted on the secondary planetary shaft 13 via planetary bearings. The secondary sun gear 10 meshes with the multiple secondary planetary gears 11, which in turn mesh with the second internal gear ring 9 mounted on the housing 1.

[0023] The three-stage planetary gearset includes a three-stage sun gear 15, multiple three-stage planetary gears 16, a three-stage planet carrier 17, and a three-stage planetary shaft 18. The second-stage sun gear 10 is fixedly connected to the three-stage planetary carrier 17, to which the three-stage planetary shaft 18 is fixed. The three-stage planetary gears 16 are rotatably mounted on the three-stage planetary shaft 18 via planetary bearings. The three-stage sun gear 15 meshes with the multiple three-stage planetary gears 16, which in turn mesh with the third internal gear ring 14 provided on the housing 1.

[0024] The third-stage sun gear 15 is fixedly connected to the final-stage driving wheel 19 . The housing 1 is provided with an output shaft 21 via a final-stage bearing. An output gear 20 is fixedly provided on the output shaft 21 . The final-stage driving wheel 19 meshes with the output gear 20 .

[0025] The outer contours of the secondary planet carrier 12 and the tertiary planet carrier 17 are surface-hardened to form bearing inner rings, and the inner surface of the housing 1 is surface-hardened at the position matching the outer contours of the planet carrier to form bearing outer rings, with rolling elements 8 arranged therebetween to form planet carrier bearings 22.

[0026] In this embodiment, there are four primary planetary gears 5, four secondary planetary gears 11, and four tertiary planetary gears 16. The planetary gear set is constructed of medium-carbon steel, and the outer surfaces of the planetary shafts (primary planetary shaft 7, secondary planetary shaft 13, and tertiary planetary shaft 18) and the inner surfaces of the planetary gears (primary planetary gear 5, secondary planetary gear 11, and tertiary planetary gear 16) are surface hardened.

[0027] like Figure 3 As shown, the outer contours of the secondary planet carrier 12 and the tertiary planet carrier 17 are provided with a first radial protrusion 23, the housing 1 is provided with a second radial protrusion 24, and the rolling element 8 is axially arranged between the first radial protrusion 23 and the second radial protrusion 24 to form a planet carrier bearing 22.

[0028] An axial load-bearing bearing 25 is further provided between the planet carriers (the first planet carrier 6, the second planet carrier 12, and the third planet carrier 17) and the inner gear rings (the first inner gear ring 3, the second inner gear ring 9, and the third inner gear ring 14). The load-bearing bearing 25 is used to further bear the axial force of the gearbox.

[0029] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A gearbox with a single-arm planetary carrier structure, comprising a housing, wherein an input shaft, at least one set of planetary gear sets, and an output shaft are disposed within the housing, which are sequentially connected in a transmission manner; the planetary gear set comprises a planetary carrier, a planetary gear shaft, planetary gears, and a sun gear, the planetary gear shaft being fixed to the planetary carrier, the planetary gears being disposed on the planetary gear shaft via planetary bearings, an internal gear ring being disposed within the housing at a position adapted to the planetary gears, the planetary gears being meshed with both the sun gear and the internal gear ring, and characterized in that: The outer contour of the planet carrier is surface quenched to form the inner ring of the bearing, the inner surface of the housing and the matching position of the outer contour of the planet carrier are surface quenched to form the outer ring of the bearing, and rolling elements are provided between the inner ring of the bearing and the outer ring of the bearing to form a planet carrier bearing.

2. The gearbox with a single-arm planetary carrier structure according to claim 1, characterized in that: The inner ring of the planetary bearing is integrally formed with the planetary gear shaft, and the outer ring of the planetary bearing is integrally formed with the planetary gear; a rolling body is provided between the inner ring and the outer ring of the planetary bearing.

3. The gearbox with a single-arm planetary carrier structure according to claim 1, characterized in that: It includes multiple sets of planetary gear sets, and the sun gear of the upper stage is fixedly connected to the planet carrier of the lower stage.

4. The gearbox with a single-arm planetary carrier structure according to claim 2, characterized in that: The planetary gear set is made of medium carbon steel, and the outer surface of the planetary shaft and the inner surface of the planetary gear are surface quenched.

5. The gearbox with a single-arm planetary carrier structure according to claim 1, characterized in that: The planetary gear set includes a first-stage planetary gear set, a second-stage planetary gear set, and a third-stage planetary gear set; The first-stage planetary gear set includes a first-stage sun gear, a first-stage planetary gear, a first-stage planetary carrier, and a first-stage planetary shaft; the input shaft is fixedly connected to the first-stage planetary carrier, the first-stage sun gear is meshed with a plurality of first-stage planetary gears, and the first-stage planetary gears are simultaneously meshed with a first internal gear ring provided on the housing, and the first-stage planetary gears are rotatably provided on the first-stage planetary shaft via planetary bearings; The secondary planetary gear set includes a secondary sun gear, secondary planetary gears, a secondary planetary carrier, and a secondary planetary shaft; the primary sun gear is fixedly connected to the secondary planetary carrier, the secondary sun gear is meshed with a plurality of secondary planetary gears, the secondary planetary gears are also meshed with a second inner gear ring provided on the housing, and the secondary planetary gears are rotatably provided on the secondary planetary shaft via planetary bearings; The three-stage planetary gear set includes a three-stage sun gear, three-stage planetary gears, a three-stage planet carrier, and a three-stage planetary shaft; the second-stage sun gear is fixedly connected to the third-stage planet carrier, the third-stage sun gear is meshed with a plurality of three-stage planetary gears, and the three-stage planetary gears are also meshed with a third inner gear ring provided on the housing, and the three-stage planetary gears are rotatably provided on the three-stage planetary shaft via planetary bearings; The three-stage sun gear is fixedly connected to the final-stage driving wheel. The box body is provided with an output shaft via a final-stage bearing. An output gear is fixedly provided on the output shaft. The final-stage driving wheel is meshed with the output gear.

6. The gearbox with a single-arm planetary carrier structure according to claim 5, characterized in that: The outer diameter of the final stage driving wheel is larger than the outer diameter of the third stage sun wheel, and the outer diameter of the output gear is smaller than the outer diameter of the final stage driving wheel.

7. The gearbox with a single-arm planetary carrier structure according to claim 5, characterized in that: The inner ring of the final-stage bearing is integrally formed with the output shaft, and the outer ring of the final-stage bearing is integrally formed with the housing.

8. The gearbox with a single-arm planetary carrier structure according to claim 7, characterized in that: The inner ring and outer ring of the final-stage bearing are processed by a surface quenching process.

9. The gearbox with a single-arm planetary carrier structure according to claim 7, characterized in that: A first radial protrusion is provided on the outer contour of the secondary planet carrier and the tertiary planet carrier, a second radial protrusion is provided on the box body, and the rolling body is axially arranged between the first radial protrusion and the second radial protrusion.

Images