13-gear large-torque mechanical transmission

Abstract

A 13-gear large-torque mechanical transmission comprises a first shaft and a first shaft gear which are coaxially connected, and further comprises a second shaft coaxial with the first shaft, a plurality of gear position gears are coaxially arranged on the second shaft, and gear position synchronizers corresponding to the gear position gears are further coaxially arranged on the second shaft, and the 13-gear large-torque mechanical transmission is characterized in that second shaft spline pads are coaxially arranged between the gear position gears and the second shaft; a plurality of grooves are evenly distributed in the inner circumference of each two-shaft spline pad, limiting grooves are formed in the peripheries of the two shafts corresponding to the grooves, hexagonal keys parallel to the axes of the two shafts are arranged in the spaces between the grooves and the corresponding limiting grooves, top gaps are reserved between the hexagonal keys and the top faces of the grooves, and side gaps are reserved between the hexagonal keys and the opposite side faces of the grooves. Through reasonable arrangement of component structures, the fatigue life and static torsional strength of the 13-gear transmission are integrally improved, the matching requirement of a large-torque engine is met, and the requirements of vast customers for transportation efficiency and fuel economy are met; meanwhile, the device can be applied to 13-gear same-series products, and the purpose of reducing the market failure rate of the same-series products is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of transmission technology, specifically relating to a 13-speed high-torque mechanical transmission. Background Technology

[0002] Currently, 13-speed mechanical transmissions are favored by OEMs and customers in the complex road condition dump truck segment due to their advantages such as large top gear ratios, wide gear ratio range, and the simultaneous presence of overdrive and direct drive. Their torque range covers 2000Nm to 2600Nm. However, with the maturity and widespread adoption of high-horsepower engine technology, OEMs are increasingly deploying high-horsepower engines paired with high-torque mechanical transmissions to improve the transportation efficiency and fuel economy of vehicles operating in complex road conditions. Therefore, there is an urgent need to develop 13-speed mechanical transmissions with even higher torque to meet the demands of the high-horsepower dump truck market in complex road conditions. However, developing a 13-speed mechanical transmission with an input torque of 2800Nm, while maintaining the same overall dimensions as other 13-speed mechanical transmissions, presents the main challenge: how to improve the fatigue life and static torsional strength of the transmission assembly, reduce development costs, and shorten the development time. Summary of the Invention

[0003] To address the aforementioned problems, the purpose of this invention is to provide a 13-speed high-torque mechanical transmission, which solves the problem of how to improve the fatigue life and static torsional strength of existing 13-speed transmissions.

[0004] To achieve the above objectives, the technical solution adopted by this utility model includes:

[0005] A 13-speed high-torque mechanical transmission includes a primary shaft and a primary shaft gear coaxially connected, and a secondary shaft coaxial with the primary shaft. Multiple gears are coaxially mounted on the secondary shaft, and a synchronizer corresponding to each gear is also coaxially mounted on the secondary shaft. A secondary shaft spline washer is coaxially mounted between each gear and the secondary shaft. Multiple grooves are evenly distributed on the inner circumference of each secondary shaft spline washer. A limiting groove is provided on the outer circumference of the secondary shaft corresponding to each groove. A hexagonal key parallel to the axis of the secondary shaft is provided in the space between each groove and its corresponding limiting groove. A top clearance is provided between each hexagonal key and the top surface of the groove, and a side clearance is provided between each hexagonal key and the opposite side surface of the groove.

[0006] Preferably, the top clearance is 0.28mm to 0.37mm and the side clearance is 0.27mm to 0.38mm.

[0007] Preferably, each of the two-axis spline pads has at least one oil groove on both sides.

[0008] Preferably, the two-axis spline pad has two parallel oil grooves on each side, and the oil grooves on opposite sides are perpendicular to each other.

[0009] Preferably, the vertical distance from each oil groove to the center line of the two-axis spline pad is equal.

[0010] Preferably, the outer periphery of the end of the first shaft gear matches the inner periphery of the fifth gear side engagement tooth of the fifth and sixth gear synchronizer, and the outer periphery of the end of the first shaft gear meshes with the inner periphery of the fifth gear side engagement tooth.

[0011] Preferably, it also includes a secondary housing welding shaft, wherein the front welding seam of the secondary housing welding shaft is a semi-U-shaped weld with an angle of 45° to its axial direction.

[0012] Compared with the prior art, the advantages of this utility model are:

[0013] (1) The present invention provides a 13-speed high-torque mechanical transmission, which improves the fatigue life and static torsional strength of the 13-speed transmission by rationally setting the component structure.

[0014] (2) The 13-speed high-torque mechanical transmission of this utility model greatly restricts the rotation of the hexagonal key through the optimized design of the top clearance and side clearance, which effectively solves the problem of the hexagonal key being bitten by the hexagonal key within the contact range between the hexagonal key and the spline pad of the two shafts, and greatly improves the reliability and quality of the transmission assembly.

[0015] (3) The present invention provides a 13-speed high-torque mechanical transmission. By rationally setting the component structure, it can achieve the lubrication effect of the spline pads of each two shafts, enhance the strength of the spline pads, and improve the overall fatigue life.

[0016] (4) The present invention provides a 13-speed high-torque mechanical transmission, which significantly improves the service life of the fifth and sixth gear synchronizers by meshing the first shaft gear with the fifth gear side gear; at the same time, the semi-U-shaped weld design of the weld seam at the front end of the auxiliary gearbox welded shaft improves the fatigue strength of the auxiliary gearbox welded shaft.

[0017] (5) The present invention provides a 13-speed high-torque mechanical transmission, which is based on the 13JSDX280T transmission with an input torque of 2800Nm developed on the 13-speed mechanical transmission series platform. It can meet the matching requirements of high-torque engines, which is beneficial to the layout of high-torque dump trucks or tractors of OEMs, and meets the needs of customers for transportation efficiency and fuel economy.

[0018] (6) The 13-speed high-torque mechanical transmission of this utility model can be applied to 13-speed products of the same series, so as to reduce the failure rate of products of the same series in the market. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the following detailed description to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the structure of a 13-speed high-torque mechanical transmission;

[0021] Figure 2 A schematic diagram showing the clearance between the spline and hexagonal key inside the two-axis spline pad;

[0022] Figure 3 This is a schematic diagram of the structure of a two-axis spline pad;

[0023] Figure 4 for Figure 3 Radial view;

[0024] Figure 5 This is a schematic diagram of the meshing of a gear and a synchronizer; where 5a is the schematic diagram before optimization, and 5b is the schematic diagram of the scheme of this application (after optimization);

[0025] Figure 6 This is a schematic diagram of the weld seam of the auxiliary box welding shaft; where 6a is an axial sectional view of the auxiliary box welding shaft and 6b is a three-dimensional schematic diagram of the auxiliary box welding shaft.

[0026] Figure 7 This is a radial cross-sectional view of one axis.

[0027] The labels in the diagram represent:

[0028] 1. Shaft 1; 2. Shaft 1 gear; 3. Intermediate shaft drive gear; 4. Intermediate shaft; 5. Intermediate shaft third gear; 6. Second shaft third gear; 7. Synchronizer; 71. Gear hub; 8. Second shaft; 80. Limiting groove; 9. Auxiliary gearbox drive gear; 10. Auxiliary gearbox intermediate shaft drive gear; 11. Auxiliary gearbox intermediate shaft; 12. Auxiliary gearbox reduction gear; 13. Auxiliary gearbox synchronizer sleeve; 14. Auxiliary gearbox main shaft; 15. Flange; 16. Hexagonal key; 17. Second shaft spline gasket; 170. Groove; 171. Oil groove; 17a. Top clearance; 17b. Side clearance; 18. Fifth and sixth gear synchronizer; 181. Fifth gear side engagement gear; 19. Second shaft spline gasket; 20. Second shaft overspeed gear; 21. Auxiliary gearbox welded shaft; 21a. Front weld seam. Detailed Implementation

[0029] The utility model is not limited to the following specific embodiments. All equivalent modifications made based on the technical solution of this application fall within the protection scope of this utility model.

[0030] It should be noted that the directional terms mentioned in this article, such as "inner cavity", "inner circumference" and "outer circumference", are consistent with the specific directions on the paper in the drawings of the specification or the corresponding directions of the space shown in the drawings; all components and devices in this utility model, unless otherwise specified, adopt components and devices known in the prior art.

[0031] Example

[0032] This embodiment discloses a 13-speed high-torque mechanical transmission, including a primary shaft 1 and a primary shaft gear 2 coaxially connected, and a secondary shaft 8 coaxial with the primary shaft 1. Multiple gears are coaxially mounted on the secondary shaft 8, and a synchronizer corresponding to each gear is also coaxially mounted on the secondary shaft 8. A secondary shaft spline washer 17 is coaxially positioned between each gear and the secondary shaft 8. Multiple grooves 17-0 are evenly distributed on the inner circumference of each secondary shaft spline washer 17, and the outer circumference of the secondary shaft 8 corresponding to each groove 17-0 is... Each groove 17-0 has a limiting groove 8-0, and a hexagonal key 16 parallel to the axis of the two shafts 8 is provided in the space between each groove 17-0 and the corresponding limiting groove 8-0. A top gap 17a is left between each hexagonal key 16 and the top surface of the groove 17-0, and a side gap 17b is left between each hexagonal key 16 and the opposite side surface of the groove 17-0. In this embodiment, the preferred value of the top gap 17a is 0.28mm to 0.37mm, and the preferred value of the side gap 17b is 0.27mm to 0.38mm.

[0033] Through the optimized design of the top clearance 17a and side clearance 17b, the rotation of the hexagonal key 16 is greatly constrained, effectively solving the problem of the hexagonal key 16 being chewed up within the contact area between the hexagonal key 16 and the two-shaft spline pad 17. Simultaneously, the toothed hub of each gear synchronizer disclosed in this embodiment is widened to 23.92mm~24mm, effectively reducing the failure of synchronizer toothed hub cracking and increasing the mating length of the hexagonal key at the synchronizer toothed hub, which also greatly constrains the rotation of the hexagonal key 16. Based on after-sales fault analysis of the 13-speed series products, this embodiment conducts targeted analysis for different fault modes and implements them in the 13JSDX280T transmission, resulting in a significant improvement in the reliability and quality of the transmission assembly.

[0034] Specifically, each of the two-axis spline pads 17 has at least one oil groove 17-1 on both sides to improve the lubrication conditions of each of the two-axis spline pads 17.

[0035] Taking into account both the strength and cost factors of the dual-axis spline pad 17, the dual-axis spline pad 17 disclosed in this embodiment is provided with two parallel oil grooves 17-1 on both sides, and the oil grooves 17-1 on opposite sides are perpendicular to each other; and the vertical distance from each oil groove 17-1 to the center line of the dual-axis spline pad 17 is equal to enhance the strength of the spline pad. The oil grooves 17-1 in this embodiment can be forged.

[0036] Based on current market failure performance, this embodiment increases the thickness of the two-axis spline pad 17 to 8mm to 8.05mm to further enhance its strength and take into account changes in the transmission assembly.

[0037] Specifically, the outer circumference of the end of the first shaft gear 2 matches the inner circumference structure of the fifth gear side engagement tooth 18-1 of the fifth and sixth gear synchronizer 18, and the outer circumference of the end of the first shaft gear 2 meshes with the inner circumference of the fifth gear side engagement tooth 18-1. This means that the original internal meshing is changed to external meshing, and the meshing circle radius is increased. Based on the fault performance of the 13-speed series products, the service life of the fifth and sixth gear synchronizer 18 can be significantly improved.

[0038] This embodiment also includes a secondary housing welding shaft 21. The front weld seam 21a of the secondary housing welding shaft 21 is a semi-U-shaped weld with an angle of 45° to its axial direction, in order to improve the fatigue strength of the secondary housing welding shaft 21. The secondary housing welding shaft 21 in this embodiment is composed of a secondary housing intermediate shaft transmission gear 10 and a secondary housing intermediate shaft 11.

[0039] The 13-speed high-torque mechanical transmission disclosed in this embodiment can use 42CrMoH material and a local high-frequency quenching process to improve the static torsional strength of the auxiliary gearbox main shaft 14. After local high-frequency quenching, the surface hardness of the auxiliary gearbox main shaft is required to be no less than HRC55, and the effective hardened layer depth at the spline root is 5-8mm.

[0040] In this embodiment, to improve the static torsional strength of shaft 1, the connecting spline of shaft 1 is a 24-tooth involute structure, which increases its breaking torque and yield torque by 1.21 to 1.39 times.

[0041] In this embodiment, to improve the static torsional strength of the entire gearbox and enhance the strength of the auxiliary gearbox synchronizer sleeve 13 and the auxiliary gearbox main shaft reduction gear 12, the meshing pair of the auxiliary gearbox synchronizer sleeve 13 and the auxiliary gearbox main shaft reduction gear 12 is moved back 2.8mm based on the existing structure, so that the meshing pair is closer to the support of the auxiliary gearbox main shaft reduction gear 12. The shortening of its cantilever length can significantly improve the static torsional strength of the gearbox in low gears.

[0042] The overall solution in this embodiment is designed based on after-sales fault analysis of the 13-speed 2000Nm~2600Nm series products. Improvement schemes and measures are formulated and implemented for the 13JSDX280T, which can be completely transplanted and applied to the same series of 13-speed products to achieve the goal of reducing the market failure rate of the same series of products.

[0043] The specific working process of this embodiment, taking three gears as an example, is as follows:

[0044] First, the driver controls the vehicle's air circuit to make the main gearbox synchronizer 7 mesh with the second shaft third gear 6, and the auxiliary gearbox synchronizer 13 mesh with the auxiliary gearbox reduction gear 12;

[0045] Secondly, the engine's output torque is input to the transmission assembly via shaft 1. The transmission path of the torque input via shaft 1 inside the transmission is as follows: shaft 1 → shaft 2 → intermediate shaft drive gear 3 → intermediate shaft 4 → intermediate shaft third gear 5 → second shaft third gear 6 → synchronizer 7 → second shaft 8 → auxiliary gearbox drive gear 9 → auxiliary gearbox intermediate shaft drive gear 10 → auxiliary gearbox intermediate shaft 11 → auxiliary gearbox reduction gear 12 → auxiliary gearbox synchronizer sleeve 13 → auxiliary gearbox main shaft 14 → flange 15.

[0046] At this point, the torque output from the engine is transmitted through the gearbox to the rear transmission system, which is connected to the gearbox flange 15.

[0047] The power transmission path for other gears is analyzed using the same method as the power transmission path for gear 3 above, and will not be repeated here.

[0048] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0049] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately. Furthermore, the various different embodiments disclosed in this solution can also be combined arbitrarily, as long as they do not violate the spirit of this disclosure.

Claims

1. A 13-speed high-torque mechanical transmission, comprising a primary shaft (1) and a primary shaft gear (2) coaxially connected, and a secondary shaft (8) coaxial with the primary shaft (1), wherein multiple gears are coaxially mounted on the secondary shaft (8), and a synchronizer corresponding to each gear is coaxially mounted on the secondary shaft (8), characterized in that, Each gear is coaxially provided with a two-shaft spline pad (17) between the gear and the two shaft (8). Multiple grooves (17-0) are evenly distributed on the inner circumference of each two-shaft spline pad (17). A limiting groove (8-0) is provided on the outer circumference of the two shaft (8) corresponding to each groove (17-0). A hexagonal key (16) parallel to the axis of the two shaft (8) is provided in the space between each groove (17-0) and the corresponding limiting groove (8-0). A top gap (17a) is left between each hexagonal key (16) and the top surface of the groove (17-0). A side gap (17b) is left between each hexagonal key (16) and the opposite side surface of the groove (17-0).

2. The 13-speed high-torque mechanical transmission as described in claim 1, characterized in that, The top gap (17a) has a value of 0.28 mm to 0.37 mm, and the side gap (17b) has a value of 0.27 mm to 0.38 mm.

3. The 13-speed high-torque mechanical transmission as described in claim 2, characterized in that, Each of the two-axis spline pads (17) is provided with at least one oil groove (17-1) on both sides.

4. The 13-speed high-torque mechanical transmission as described in claim 3, characterized in that, The two-axis spline pad (17) has two parallel oil grooves (17-1) on each side, and the oil grooves (17-1) on opposite sides are perpendicular to each other.

5. The 13-speed high-torque mechanical transmission as described in claim 4, characterized in that, The vertical distances from each oil groove (17-1) to the center line of the two-axis spline pad (17) are equal.

6. The 13-speed high-torque mechanical transmission as described in any one of claims 1-5, characterized in that, The outer periphery of the end of the first shaft gear (2) matches the inner periphery structure of the fifth gear side engagement tooth (18-1) of the fifth and sixth gear synchronizer (18), and the outer periphery of the end of the first shaft gear (2) meshes with the inner periphery of the fifth gear side engagement tooth (18-1).

7. The 13-speed high-torque mechanical transmission as described in claim 6, characterized in that, It also includes a secondary box welding shaft (21), the front welding seam (21a) of which is a semi-U-shaped weld with an angle of 45° to its axial direction.

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