Power split gear transmission and method for adjusting load sharing coefficient

Abstract

This invention discloses a power-splitting gear transmission device and a method for adjusting the load-sharing coefficient, comprising: an output gear and an input gear, and multiple power-splitting branches; each power-splitting branch includes an elastic shaft, a parallel gear, a splined adapter sleeve, a split gear mounted on the outer circumference of the splined adapter sleeve, and an adjusting and limiting component mounted on the outer circumference of the rear end of the elastic shaft; the splined adapter sleeve is slidably connected between the elastic shaft and the split gear; the adjusting and limiting component is used to adjust and limit the sliding position of the splined adapter sleeve, thereby adjusting the effective working shaft length on the elastic shaft between the splined adapter sleeve and the parallel gear, so as to adjust the effective torsional stiffness of the elastic shaft accordingly. This gear transmission device can achieve stepless adjustment of the effective torsional stiffness of the elastic shaft within a certain range, compensate for various errors in each branch, realize the adjustment of the load-sharing of the gear train, and thus improve the load-bearing capacity, transmission smoothness, and reliability of the reducer.

Description

Technical Field

[0001] This invention relates to the field of gear transmission technology, and in particular, to a power-split gear transmission device. Furthermore, this invention also relates to a method for adjusting the load-sharing coefficient of the aforementioned power-split gear transmission device. Background Technology

[0002] As the power levels of aviation and other industries continue to increase, the loads transmitted by their gear transmission devices are becoming increasingly larger. Single-path gear transmissions cannot meet the demands of high-power systems, leading to the increasingly widespread application of power-splitting gear transmissions. In power-splitting gear transmissions, there is always a certain amount of backlash in the gear meshing. Furthermore, due to unavoidable manufacturing errors, installation errors, and errors caused by the elastic deformation of components, the load transmitted in each branch is always unbalanced, which can severely reduce the gear's load-bearing capacity. To achieve load equalization in each branch, elastic shafts are typically installed in the branches, using the torsional deformation of the elastic shafts to balance the load transmitted in each branch. However, for ordinary elastic shafts, since their torsional stiffness cannot be changed, it is difficult to achieve complete load balance in each branch.

[0003] In reference document 1 (CN204477198U-Transmission System Load Sharing Structure), a transmission system load sharing structure is disclosed. The herringbone gear and the output gear shaft are connected by an input gear shaft and a spline adapter sleeve. The torsional deformation of the input gear shaft is used to overcome the error generated during the transmission process, so as to achieve uniform distribution of loads in the system.

[0004] Prior art document 2 (CN118188689A - Nested Variable Stiffness Elastic Shaft and Aircraft) discloses a nested variable stiffness elastic shaft. This elastic shaft includes an inner shaft and an outer shaft nested within the inner shaft. The inner shaft has a first torque transmission structure, and the outer shaft has a second torque transmission structure for matching the first torque transmission structure. A preset gap exists between the second and first torque transmission structures, which is used to generate torsional deformation when the working power of the outer shaft reaches a preset value, thereby eliminating the preset gap and allowing the first and second torque transmission structures to cooperate in transmitting torque. In low-power mode, power is transmitted through the outer shaft, and the torsional stiffness of the elastic shaft is the same as the torsional stiffness of the outer shaft. When the power reaches the preset value, the torsional deformation generated on the outer shaft eliminates the preset gap between the second and first torque transmission structures, and the inner and outer shafts jointly transmit power. The torsional stiffness of the elastic shaft is the sum of the stiffnesses of the inner and outer shafts. This flexible shaft can achieve a smaller torsional stiffness under low power conditions and a larger torsional stiffness under high power conditions, ensuring the required torsional stiffness while also ensuring load-sharing performance under various power conditions.

[0005] The shortcomings of these two comparative documents are as follows:

[0006] The main disadvantages of the load-sharing structure of the transmission system disclosed in document 1 are:

[0007] 1) The torsional stiffness of the input gear shaft is not adjustable, and it is impossible to fully compensate for various errors in each branch through the torsional deformation of the input gear shaft;

[0008] 2) The actual torsional stiffness of the input gear shaft is greatly affected by its own wall thickness tolerance and wall thickness uniformity, making it difficult to ensure the consistency between the actual torsional stiffness and the theoretical torsional stiffness required for the gear train to share the load; a separate stiffness test of the hollow thin-walled shaft needs to be carried out to calibrate the actual torsional stiffness of the hollow thin-walled shaft.

[0009] The main disadvantages of the nested variable stiffness elastic shaft disclosed in document 2 are as follows:

[0010] 1) The elastic shaft can only provide two torsional stiffness values ​​(i.e., the torsional stiffness of the outer shaft is used in low power mode, and the sum of the stiffness of the inner shaft and the outer shaft is used in high power mode), and cannot achieve stepless adjustment of torsional stiffness;

[0011] 2) Under a certain power condition, the torsional stiffness of the elastic shaft is a fixed value, and the torsional deformation of the elastic shaft cannot completely compensate for the various errors of each branch.

[0012] 3) The actual torsional stiffness of the elastic shaft is greatly affected by its own wall thickness tolerance and wall thickness uniformity, making it difficult to ensure the consistency between the actual torsional stiffness and the theoretical torsional stiffness required for the gear train to share the load; a separate elastic shaft stiffness test needs to be carried out to calibrate the actual torsional stiffness of the elastic shaft. Summary of the Invention

[0013] This invention provides a power splitting gear transmission device and a method for adjusting the load sharing coefficient, in order to solve the technical problem that the torsional stiffness of the existing transmission system load sharing structure is not adjustable, and the actual torsional stiffness is greatly affected by its own wall thickness tolerance and wall thickness uniformity, making it difficult to ensure the consistency between the actual torsional stiffness and the theoretical torsional stiffness required for the load sharing of the gear system.

[0014] The technical solution adopted in this invention is as follows:

[0015] A power-splitting gear transmission device includes: an output gear and an input gear arranged sequentially at intervals, and multiple power-splitting branches arranged circumferentially between the output gear and the input gear for transferring power from the input gear to the output gear; each power-splitting branch includes an elastic shaft extending in the power transmission direction, a parallel gear and a spline adapter sleeve sequentially mounted on the outer circumferences of the front and rear ends of the elastic shaft, a splitting gear mounted on the outer circumference of the spline adapter sleeve, and an adjustment and limiting assembly mounted on the outer circumference of the rear end of the elastic shaft and connecting the spline adapter sleeve and the splitting gear; the parallel gear is externally meshed with the output gear, the splitting gear is externally meshed with the input gear, and the spline adapter sleeve is slidably connected between the elastic shaft and the splitting gear; the adjustment and limiting assembly is used to adjust and limit the sliding position of the spline adapter sleeve, thereby adjusting the effective working shaft length on the elastic shaft between the spline adapter sleeve and the parallel gear, so as to adjust the effective torsional stiffness of the elastic shaft accordingly.

[0016] Furthermore, the elastic shaft is a hollow thin-walled shaft; the spline adapter sleeve is a hollow cylindrical shape, with a first external spline on its outer ring surface and a first internal spline in the inner shaft hole of the split gear. The spline adapter sleeve and the split gear are slidably connected to form a first spline pair through the cooperation of the first external spline and the first internal spline; the inner ring surface of the spline adapter sleeve is provided with a second internal spline, and the outer circle of the rear end of the elastic shaft is provided with a second external spline. The spline adapter sleeve and the elastic shaft are slidably connected to form a second spline pair through the cooperation of the second internal spline and the second external spline.

[0017] Furthermore, the outer circle of the rear end of the elastic shaft is provided with a first external thread, and the shaft hole at the rear end of the spline adapter sleeve is provided with a first inner ring cavity and a second inner ring cavity arranged sequentially along the axial direction; the adjusting and limiting assembly includes an adjusting and limiting nut and a first elastic retaining ring, the rear end of the adjusting and limiting nut is threaded to the first external thread through a connecting flange protruding along the center, and the front end of the adjusting and limiting nut is installed in the second inner ring cavity through a first outwardly protruding shoulder; the first elastic retaining ring is installed on the rear end of the spline adapter sleeve and is clamped in the first inner ring cavity so that the first shoulder is clamped in the second inner ring cavity.

[0018] Furthermore, the shaft hole at the rear end of the split gear is provided with a third inner ring cavity and a fourth inner ring cavity arranged sequentially along the axial direction; the adjustment and limiting assembly also includes a toothed stop ring slidably installed in the fourth inner ring cavity along the axial direction, and a second elastic retaining ring clamped in the third inner ring cavity; the toothed stop ring is also fitted on the outer circle of the adjustment and limiting nut to restrict the adjustment and limiting nut from rotating in the circumferential direction, and one side of the toothed stop ring also abuts against the second elastic retaining ring for limitation.

[0019] Furthermore, the outer ring surface of the toothed stop ring is slidably connected to the bottom surface of the fourth inner ring cavity through the third spline pair. The inner ring surface of the toothed stop ring is also provided with multiple outwardly protruding stop teeth that are spaced apart in sequence along the circumference. The outer ring surface of the adjusting limit nut is provided with multiple stop grooves that are provided one by one with the multiple stop teeth. Each stop groove extends along the axial direction of the adjusting limit nut to penetrate the rear end face of the adjusting limit nut.

[0020] Furthermore, the outer circle at the front end of the elastic shaft is provided with a second external thread, a fourth external spline, and a protruding second shoulder arranged sequentially along the axial direction; the inner shaft hole of the parallel gear is provided with a fourth internal spline, and the parallel gear and the elastic shaft are slidably connected by the cooperation of the fourth internal spline and the fourth external spline, and the front end face of the inner cavity of the parallel gear abuts against the second shoulder for limitation; a locking nut is installed on the second external thread of the elastic shaft, and the locking nut abuts against the front end face of the parallel gear to limit the parallel gear.

[0021] Furthermore, let L2 be the distance between the front end face of the first external thread on the elastic shaft and the front end face of the connecting flange on the adjusting limit nut; let L3 be the distance between the front end face of the first internal spline of the split gear or the front end face of the second external spline of the elastic shaft, which is closer to the front end face of the spline adapter sleeve, and the front end face of the spline adapter sleeve; then L3≥L2; the difference between the minor diameter of the second and fourth external splines on the elastic shaft and the outer diameter of the middle section on the elastic shaft located between the second and fourth external splines is within ±0.02mm.

[0022] According to another aspect of the present invention, a method for adjusting the load sharing coefficient of a power-splitting gear transmission is also provided, employing a power-splitting gear transmission as described above, and wherein the power-splitting gear transmission has only two power-splitting branches. The method for adjusting the load sharing coefficient includes the following steps: setting the load sharing coefficient η of the gear train: Torque Calculation: Apply input torque multiple times and measure the torsional angle of the elastic shaft on each of the two branches under each input torque. Calculate the effective torsional stiffness value of the elastic shaft in each branch, and obtain the specific values ​​of the transmitted torque in both branches. Substitution Calculation Judgment: Substitute the specific values ​​of the transmitted torque in both branches into Formula 1 to calculate the wheel system load sharing coefficient. If the wheel system load sharing coefficient meets the set target value, the operation terminates; otherwise, continue to the next step. Adjust Stiffness and Recalculate: Adjust the position of the spline adapter sleeve in the branch with the smaller transmitted torque value to increase the effective torsional stiffness of the elastic shaft in that branch. Re-input the torque to calculate the effective torsional stiffness value of the adjusted branch, and obtain the specific values ​​of the transmitted torque in both branches. Re-substitute Calculation Judgment: Substitute the specific values ​​of the transmitted torque in both branches back into Formula 1 to calculate the wheel system load sharing coefficient. If the wheel system load sharing coefficient does not meet the set target value, continue the "Adjust Stiffness and Recalculate" step for iterative calculation until the wheel system load sharing coefficient meets the set target value.

[0023] Furthermore, the step "applying torque calculation" specifically includes the following steps: S201: Let the effective torsional stiffness of the elastic shafts on the first branch and the second branch at the initial position be respectively... k 1. k 2; S202: The output shaft, which is fixedly connected to the output gear, applies input torque to the input shaft, which is connected to the input gear. T 1. The torsional angle of the elastic shaft on the first and second branches was obtained by measurement. θ 1-1 , θ 2-1 The torques transmitted by the elastic shafts of the first and second branches are respectively k 1 θ 1-1 , k 2 θ 2-1 It satisfies the following geometric relationship: in i S203: The gear ratio between the splitter gear and the input gear; S203: Fix the output shaft and apply input torque to the input shaft. T 2, T 2. Take the torque of the gear transmission device under continuous long-term working conditions, and compare it with... T The angles are not equal; the torsional angles of the elastic shafts on the first and second branches are obtained by measurement. θ 1-2 , θ 2-2 The torques transmitted by the elastic shafts of the first and second branches are respectively k 1 θ 1-2 , k 2 θ 2-2 It satisfies the following geometric relationship: In Formulas 2 and 3, except k 1. k All other parameters except 2 are known values; by solving them together, we can obtain... k 1. k 2. This allows us to obtain the torque transmitted by the two branches. k 1 θ 1-2 , k 2 θ 2-2 The specific value.

[0024] Furthermore, the step "adjusting stiffness and recalculating" specifically includes the following steps: S401: Calculate the load sharing coefficient of the gear train according to Formula 1. If the load sharing coefficient does not meet the set target value, then compare the torque transmitted by the two branches. and Assuming the torque transmitted by the first branch is less than that transmitted by the second branch, increasing the effective torsional stiffness of the elastic shaft in the first branch can improve the torque transmitted by the first branch, making the torque transmitted by the two branches more balanced, thereby improving the load-sharing performance of the gear train. The required adjustment of the effective torsional stiffness of the elastic shaft in the first branch can be initially calculated using the following formula. : S402: To increase the effective torsional stiffness of the first branch elastic shaft, the adjusting limit nut needs to be moved forward by Δ. The required axial movement distance Δ of the adjusting limit nut is calculated using the following formula: S403: Fix the output shaft again and apply input torque to the input shaft. T 2. The torsional angle of the elastic shaft on the first and second branches was obtained by measurement. θ 1-3 , θ 2-3 Assume that the effective torsional stiffness of the first branch elastic shaft is at this time. Then the elastic shaft transmissions of the first branch and the second branch are respectively , k 2 θ 2-3 It satisfies the following geometric relationship: ; can be obtained through calculation This allows us to obtain the torque transmitted by the two branches. , k 2 θ 2-3 The specific value.

[0025] The present invention has the following beneficial effects:

[0026] In the transmission device of this invention, a splined adapter sleeve is slidably connected between the split gear and the elastic shaft. The axial position of the splined adapter sleeve can be adjusted and locked by an adjusting limiting component. By adjusting the axial position of the splined adapter sleeve, the effective working shaft length on the elastic shaft between the splined adapter sleeve and the parallel gear can be adjusted accordingly, thereby adjusting the effective torsional stiffness of the elastic shaft. This achieves stepless adjustment of the effective torsional stiffness of the elastic shaft within a certain range, balancing the load transmitted in each branch, compensating for various errors in each branch, and adjusting the load distribution of the gear train. This improves the load-bearing capacity, transmission smoothness, and reliability of the reducer. In the transmission device of this invention, when adjusting the load distribution of the gear train, it does not rely on the overall torsional stiffness of the elastic shaft, nor does it need to consider the influence of the elastic shaft's own wall thickness tolerance, wall thickness uniformity, etc., on the overall torsional stiffness of the elastic shaft. Furthermore, by precisely adjusting the effective torsional stiffness of the elastic shaft, the torque transmitted in each branch can achieve a completely balanced state in engineering applications. That is, the torsional deformation of the elastic shaft compensates for gear meshing backlash, as well as errors caused by various manufacturing errors, installation errors, and elastic deformation of components.

[0027] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 This is a schematic diagram of a power splitting gear transmission device according to a preferred embodiment of the present invention;

[0030] Figure 2 yes Figure 1 Schematic diagram of the elastic shaft and its related connection structure;

[0031] Figure 3 yes Figure 2 A magnified view of the structure at point A in the middle;

[0032] Figure 4 yes Figure 3 Schematic diagram of the spatial structure of the toothed retaining ring;

[0033] Figure 5 yes Figure 3 Schematic diagram of the spatial structure of the adjusting limit nut;

[0034] Figure 6 yes Figure 2 Schematic diagram of the spline adapter sleeve in its initial position;

[0035] Figure 7 yes Figure 2 A schematic diagram showing the spline adapter sleeve in its predetermined position.

[0036] Legend:

[0037] 3. Output gear; 4. Input gear;

[0038] 5. Power shunt branch;

[0039] 51. Flexible shaft; 511. First external thread; 52. Parallel turning gear; 53. Spline adapter sleeve; 54. Diverter gear;

[0040] 55. Adjusting limit assembly; 551. Adjusting limit nut; 5511. Stop groove; 552. First elastic retaining ring; 553. Toothed retaining ring; 5531. Stop tooth; 554. Second elastic retaining ring;

[0041] 561. First spline sub-section; 562. Second spline sub-section; 563. Third spline sub-section; 564. Fourth spline sub-section;

[0042] 57. Tighten the nut. Detailed Implementation

[0043] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. 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.

[0044] Those skilled in the art will understand that, unless specifically stated otherwise, the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, components, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, and / or combinations thereof. It should be understood that when we say a component is "connected" to another component, it can be directly connected to the other component or connected via an intermediate component. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items. The terms "first" and "second," etc., in this specification and claims are used to distinguish different objects, not to describe a particular order.

[0045] Reference Figure 1 and Figure 2 A preferred embodiment of the present invention provides a power-splitting gear transmission device, comprising: an output gear 3 and an input gear 4 arranged sequentially at intervals, and multiple power-splitting branches 5 arranged circumferentially between the output gear 3 and the input gear 4 for transferring power from the input gear 4 to the output gear 3; each power-splitting branch 5 includes an elastic shaft 51 extending along the power transmission direction, a parallel gear 52 and a spline adapter sleeve 53 sequentially mounted on the outer circumferences of the front and rear ends of the elastic shaft 51 along the axial direction, and a power-splitting gear 53 mounted on the outer circumference of the spline adapter sleeve 53. 4. An adjusting and limiting assembly 55 is installed on the outer circle of the rear end of the elastic shaft 51 and connects the spline adapter sleeve 53 and the flow divider gear 54; the parallel gear 52 is externally meshed with the output gear 3, the flow divider gear 54 is externally meshed with the input gear 4, and the spline adapter sleeve 53 is slidably connected between the elastic shaft 51 and the flow divider gear 54; the adjusting and limiting assembly 55 is used to adjust and limit the sliding position of the spline adapter sleeve 53, thereby adjusting the effective working shaft length of the elastic shaft 51 between the spline adapter sleeve 53 and the parallel gear 52, so as to adjust the effective torsional stiffness of the elastic shaft 51 accordingly.

[0046] When the power splitting gear transmission device of the present invention is working, the power is first transmitted to the input gear 4, and then transmitted to the output gear 3 through multiple power splitting branches 5, and finally output to the outside through the output gear 3; in each power splitting branch 5, the power is input from the splitting gear 54, and then transmitted to the parallel gear 52 through the spline adapter sleeve 53 and the elastic shaft 51 in sequence, and finally transmitted to the output gear 3 by the parallel gear 52.

[0047] In the transmission device of the present invention, the spline adapter sleeve 53 is slidably connected between the split gear 54 and the elastic shaft 51. The axial position of the spline adapter sleeve 53 can be adjusted and locked by the adjusting limiting component 55. Therefore, by adjusting the axial position of the spline adapter sleeve 53, the effective working shaft length on the elastic shaft 51 between the spline adapter sleeve 53 and the parallel gear 52 can be adjusted accordingly, thereby adjusting the effective torsional stiffness of the elastic shaft 51. This achieves stepless adjustment of the effective torsional stiffness of the elastic shaft 51 within a certain range, balancing the load transmitted in each branch, compensating for various errors in each branch, and realizing… The adjustment of the load distribution of the gear train improves the load-bearing capacity, transmission smoothness, and reliability of the reducer. In the transmission device of this invention, when adjusting the load distribution of the gear train, it does not rely on the overall torsional stiffness of the elastic shaft 51, nor does it need to consider the influence of the wall thickness tolerance and wall thickness uniformity of the elastic shaft 51 on the overall torsional stiffness of the elastic shaft. Furthermore, by precisely adjusting the effective torsional stiffness of the elastic shaft, the torque transmitted by each branch can reach a completely balanced state in the engineering application sense. That is, the torsional deformation of the elastic shaft 51 compensates for the gear meshing backlash, as well as the errors caused by various manufacturing errors, installation errors, and elastic deformation of components.

[0048] Optionally, such as Figure 2 As shown, the elastic shaft 51 is a hollow thin-walled shaft to compensate for various errors through torsional deformation. The spline adapter sleeve 53 is a hollow cylindrical shape with a first external spline on its outer ring surface and a first internal spline in the inner shaft hole of the flow divider gear 54. The spline adapter sleeve 53 and the flow divider gear 54 are slidably connected to form a first spline pair 561 through the cooperation of the first external spline and the first internal spline. The inner ring surface of the spline adapter sleeve 53 is provided with a second internal spline, and the outer circle of the rear end of the elastic shaft 51 is provided with a second external spline. The spline adapter sleeve 53 and the elastic shaft 51 are slidably connected to form a second spline pair 562 through the cooperation of the second internal spline and the second external spline.

[0049] Optionally, such as Figure 2 and Figure 3As shown, the outer circle of the rear end of the elastic shaft 51 is provided with a first external thread 511, and the shaft hole at the rear end of the spline adapter sleeve 53 is provided with a first inner ring cavity and a second inner ring cavity arranged sequentially along the axial direction; the adjusting limit assembly 55 includes an adjusting limit nut 551 and a first elastic retaining ring 552. The rear end of the adjusting limit nut 551 is threaded to the first external thread through a connecting flange protruding along the center, and the front end of the adjusting limit nut 551 is installed in the second inner ring cavity through a first outwardly protruding shoulder; the first elastic retaining ring 552 is installed on the rear end of the spline adapter sleeve 53 and is clamped in the first inner ring cavity so that the first shoulder is clamped in the second inner ring cavity. In this optional solution, the rear end faces of the adjusting limit nut 551 and the spline adapter sleeve 53 are in contact, and the first elastic retaining ring 552 is used for axial limiting. The adjusting limit nut 551 and the spline adapter sleeve 53 are only in contact at their end faces, and can rotate circumferentially between them. Then, the adjusting limit nut 551 can be turned by applying force, and the spline adapter sleeve 53 can be driven to slide back and forth on the elastic shaft 51 by adjusting the adjusting limit nut 551.

[0050] Preferably, such as Figure 2 and Figure 3 As shown, the shaft hole at the rear end of the flow divider gear 54 has a third inner ring cavity and a fourth inner ring cavity arranged sequentially along the axial direction; the adjusting and limiting assembly 55 also includes a toothed stop ring 553 slidably mounted in the fourth inner ring cavity along the axial direction, and a second elastic retaining ring 554 clamped in the third inner ring cavity; the toothed stop ring 553 is also fitted on the outer circle of the adjusting and limiting nut 551 to restrict the circumferential rotation of the adjusting and limiting nut 551, and one side of the toothed stop ring 553 abuts against the second elastic retaining ring 554 for limiting. When the adjusting and limiting nut 551 reaches the predetermined axial position relative to the elastic shaft 51, the toothed stop ring 553 is installed on the flow divider gear 54 and clamped in the fourth inner ring cavity, while being axially limited by the second elastic retaining ring 554 clamped in the third inner ring cavity.

[0051] In this preferred embodiment, such as Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, the outer ring surface of the toothed stop ring 553 is slidably connected to the bottom surface of the fourth inner ring cavity through a third spline pair 563. The inner ring surface of the toothed stop ring 553 is also provided with multiple outwardly protruding stop teeth 5531 arranged sequentially and circumferentially. The outer ring surface of the adjusting limit nut 551 is provided with multiple stop grooves 5511 corresponding to the multiple stop teeth 5531. Each stop groove 5511 extends axially along the adjusting limit nut 551 to penetrate the rear end face of the adjusting limit nut 551. In this preferred embodiment, the toothed stop ring 553 has stop teeth 5531 on its inner side, whose positions correspond to the stop grooves 5511 on the outer circle of the adjusting limit nut 551. The toothed stop ring 553 can restrict the circumferential rotation of the adjusting limit nut 551, thereby restricting the axial movement of the adjusting limit nut 551 relative to the elastic shaft 51, keeping it in a predetermined axial position.

[0052] Optionally, such as Figure 2 As shown, the outer circle at the front end of the elastic shaft 51 is also provided with a second external thread, a fourth external spline, and a second protruding shoulder arranged sequentially along the axial direction; the inner shaft hole of the parallel gear 52 is provided with a fourth internal spline, and the parallel gear 52 and the elastic shaft 51 are slidably connected by the cooperation of the fourth internal spline and the fourth external spline to form a fourth spline pair 564, and the front end face of the inner cavity of the parallel gear 52 abuts against the second shoulder for limitation; a locking nut 57 is installed on the second external thread of the elastic shaft 51, and the locking nut 57 abuts against the front end face of the parallel gear 52 to limit the parallel gear 52.

[0053] Preferably, such as Figure 6 As shown, let L2 be the distance between the front end face of the first external thread on the elastic shaft 51 and the front end face of the connecting flange on the adjusting limit nut 551; let L3 be the distance between the front end face of the first internal spline of the split gear 54 or the front end face of the second external spline of the elastic shaft 51, which is closer to the front end face of the spline adapter sleeve 53, and the front end face of the spline adapter sleeve 53; then L3≥L2, thereby ensuring that when the adjusting limit nut 551 can move forward to the limit position (i.e., L2=0), the spline adapter sleeve 53 is still in contact, thereby increasing the torsional stiffness adjustment range of the elastic shaft 51.

[0054] Preferably, such as Figure 6As shown, for simplicity, during power transmission, the center section of the spline pair contact area is considered the load-bearing surface. The distance between the load-bearing surfaces of the second spline pair 562 and the fourth spline pair 564 is L1, which is the effective working length of the elastic shaft 51. This length corresponds to the effective torsional stiffness of the elastic shaft. By axially moving the spline adapter sleeve 53, the effective working length of the elastic shaft 51 can be changed, thereby changing the effective torsional stiffness of the elastic shaft 51. The effective working length of the elastic shaft 51 can continuously vary within the range of (L1-L2) to L1, thus achieving stepless variation of the effective torsional stiffness. In structural design, the minor diameter of both the second and fourth external splines on the elastic shaft 51 can be set to within ±0.02 mm of the outer diameter of the intermediate section between the second and fourth external splines on the elastic shaft 51. In this case, the effective torsional stiffness of the elastic shaft can be considered to have a linear relationship with its length.

[0055] Preferably, such as Figure 6 As shown, let L4 be the distance from the rear end face of the adjusting limit nut 551 to the rear end face of the elastic shaft 51. This value is used to precisely control the axial position of the adjusting limit nut 551, thereby precisely adjusting the effective torsional stiffness of the elastic shaft.

[0056] A preferred embodiment of the present invention also provides a method for adjusting the load sharing coefficient of a power-splitting gear transmission device, which employs any of the power-splitting gear transmission devices described above, and assumes that the power-splitting gear transmission device has only two power-splitting branches 5. The method for adjusting the load sharing coefficient includes the following steps:

[0057] S10: Set the load-sharing coefficient η of the gear train: Formula 1;

[0058] S20: Torque calculation: Apply the input torque multiple times and measure the torsion angle of the elastic shaft 51 on the two branches under each input torque. Then calculate the effective torsional stiffness value of the elastic shaft 51 in each branch and obtain the specific value of the torque transmitted in the two branches.

[0059] S30: Substitution Calculation Judgment: Substitute the specific values ​​of the torque transmitted by the two branches into Formula 1 to calculate the wheel system load sharing coefficient. If the wheel system load sharing coefficient meets the set target value, the operation terminates; otherwise, continue to the next step.

[0060] S40: Adjust stiffness and recalculate: Adjust the position of the spline adapter sleeve 53 in the branch with the smaller specific value of the transmitted torque to increase the effective torsional stiffness of the elastic shaft 51 in the branch accordingly, and then re-enter the torque to calculate the effective torsional stiffness value of the adjusted branch, and obtain the specific values ​​of the transmitted torque of the two branches at the same time.

[0061] S50: Re-substitute calculation judgment: Substitute the specific values ​​of the torque transmitted by the two branches back into Formula 1 to calculate the wheel system load sharing coefficient. If the wheel system load sharing coefficient does not meet the set target value, continue to perform the "adjust stiffness and recalculate" step for iterative calculation until the wheel system load sharing coefficient meets the set target value.

[0062] This invention also provides a method for adjusting the load sharing coefficient of a power-split gear transmission device. By sequentially setting the load sharing coefficient η of the gear train, calculating the applied torque, substituting the values ​​into the calculation for judgment, adjusting the stiffness and recalculating, and resubstituting the values ​​into the calculation for judgment, the load sharing coefficient of the gear train can be made to meet the set target value. This eliminates the need for a separate torsional stiffness test of the elastic shaft to calibrate its torsional stiffness. The calculation process is simple and can obtain a high-precision effective torsional stiffness of the elastic shaft, thereby guiding the adjustment of the load sharing coefficient to obtain a load sharing coefficient that meets the set target value. Ultimately, this improves the load-bearing capacity, transmission smoothness, and reliability of the reducer. Furthermore, this adjustment method is not limited to the method described above. Figure 1 The two-branch configuration shown is also applicable to power split gear transmission devices with three or more branches. The elastic shaft and its related connection structure are also applicable, and load equalization can be adjusted in a similar way.

[0063] Optionally, in step "S10: Setting the load sharing coefficient η of the gear train", in actual engineering applications, the torque transmitted by the two branches generally cannot be completely equal. It is generally considered that a load sharing coefficient of 1.02 to 1.05 indicates that the load sharing performance of the gear train is good. In this invention, the load sharing coefficient of the gear train can be further improved by adjusting the effective torsional stiffness of the elastic shaft. For example, the load sharing of the gear train can be adjusted with a target load sharing coefficient of less than 1.005. At this time, it can be considered that the torque transmitted by each branch has reached a completely balanced state in the sense of engineering application.

[0064] Optionally, step "S20: Calculation of Applied Torque" specifically includes the following steps:

[0065] S201: Let the effective torsional stiffness of the elastic shaft 51 on the first branch and the second branch at the initial position be respectively... k 1. k 2;

[0066] S202: The output shaft of the fixedly connected output gear 3 applies input torque to the input shaft of the connected input gear 4. T 1. The torsion angle of the elastic shaft 51 on the first and second branches was obtained by measurement. θ 1-1 , θ 2-1 The first and second branch elastic shafts 51 transmit torques respectively. k 1 θ 1-1 , k 2 θ 2-1 It satisfies the following geometric relationship:

[0067] Formula 2;

[0068] in i The gear ratio between the split gear 54 and the input gear 4;

[0069] S203: Fixed output shaft, applying input torque to the input shaft. T 2, T 2. Take the torque of the gear transmission device under continuous long-term working conditions, and compare it with... T 1. The values ​​are not equal. The torsion angle of the elastic shaft 51 on the first and second branches is obtained by measurement. θ 1-2 , θ 2-2 The first and second branch elastic shafts 51 transmit torques respectively. k 1 θ 1-2 , k 2 θ 2-2 It satisfies the following geometric relationship:

[0070] Formula 3;

[0071] In Formulas 2 and 3, except k 1. k All other parameters except 2 are known values; by solving them together, we can obtain... k 1. k 2. This allows us to obtain the torque transmitted by the two branches. k 1 θ 1-2 , k 2 θ 2-2 The specific value.

[0072] Optionally, step "S40: Adjusting Stiffness and Recalculating" specifically includes the following steps:

[0073] S401: Calculate the load sharing coefficient of the gear train according to Formula 1. If the load sharing coefficient does not meet the set target value, compare the torque transmitted between the two branches. and The magnitude of the torque transmitted by the first branch is assumed to be less than that transmitted by the second branch;

[0074] By increasing the effective torsional stiffness of the first branch elastic shaft 51, the transmitted torque of the first branch can be improved, making the transmitted torque of the two branches more balanced, thereby improving the load-sharing performance of the gear train. The required adjustment of the effective torsional stiffness of the first branch elastic shaft 51 can be initially calculated using the following formula. :

[0075] Formula 4;

[0076] (Note: Here) (The values ​​are theoretical torsional stiffness; unless otherwise specified, they refer to actual torsional stiffness values.)

[0077] S402: To increase the effective torsional stiffness of the first branch elastic shaft 51, the adjusting limit nut 551 needs to be moved forward by Δ. Calculate the required axial movement distance Δ of the adjusting limit nut 551 using the following formula: Figure 7 As shown:

[0078] Formula 5;

[0079] S403: Fix the output shaft again and apply input torque to the input shaft. T 2. The torsion angle of the elastic shaft 51 on the first and second branches was obtained by measurement. θ 1-3 , θ 2-3 Due to the change in the effective torsional stiffness of the first branch elastic shaft, the loads of the two branches will be redistributed. The torsional angle of the elastic shaft in this step is not equal to the torsional angle of the elastic shaft in step S203. Assume that the effective torsional stiffness of the first branch elastic shaft 51 is at this time... The torques transmitted by the elastic shafts 51 in the first and second branches are respectively , k 2 θ 2-3 It satisfies the following geometric relationship:

[0080] Formula Six;

[0081] It can be obtained through calculation. This allows us to obtain the torque transmitted by the two branches. , k 2 θ 2-3 The specific value.

[0082] Optionally, in step S50, the load-sharing coefficient of the gear train is calculated again according to Formula 1 to confirm whether the load-sharing coefficient meets the set target value. If it does not meet the target value, step S40 is repeated until the load-sharing coefficient meets the target value. At this time, the torque transmitted by each branch reaches a state of complete balance in engineering applications, that is, the torsional deformation of the elastic shaft completely compensates for the gear meshing backlash, as well as the errors caused by various manufacturing errors, installation errors, and elastic deformation of components.

[0083] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A power split gearing arrangement characterised in that, include: Output gear (3) and input gear (4) are arranged sequentially and spaced apart, and multiple power shunt branches (5) are arranged circumferentially between output gear (3) and input gear (4) to transfer the power shunt on input gear (4) to output gear (3); Each power shunt branch (5) includes an elastic shaft (51) extending along the power transmission direction, a parallel gear (52) and a spline adapter sleeve (53) installed axially on the outer circles of the front and rear ends of the elastic shaft (51), a shunt gear (54) installed on the outer circle of the spline adapter sleeve (53), and an adjustment and limiting assembly (55) installed on the outer circle of the rear end of the elastic shaft (51) and connecting the spline adapter sleeve (53) and the shunt gear (54). The parallel gear (52) is externally meshed with the output gear (3), the split gear (54) is externally meshed with the input gear (4), and the spline adapter sleeve (53) is slidably connected between the elastic shaft (51) and the split gear (54). The adjusting limit component (55) is used to adjust and limit the sliding position of the spline adapter sleeve (53), thereby adjusting the effective working shaft length of the elastic shaft (51) between the spline adapter sleeve (53) and the parallel gear (52), so as to adjust the effective torsional stiffness of the elastic shaft (51) accordingly.

2. The power splitting gear transmission device according to claim 1, characterized in that, The elastic shaft (51) is a hollow thin-walled shaft; The spline adapter sleeve (53) is a hollow cylindrical shape, with a first external spline on its outer ring surface and a first internal spline in the inner shaft hole of the split gear (54). The spline adapter sleeve (53) and the split gear (54) are slidably connected to form a first spline pair (561) through the cooperation of the first external spline and the first internal spline. The inner ring surface of the spline adapter sleeve (53) is provided with a second inner spline, and the outer circle of the rear end of the elastic shaft (51) is provided with a second outer spline. The spline adapter sleeve (53) and the elastic shaft (51) are slidably connected to form a second spline pair (562) through the cooperation of the second inner spline and the second outer spline.

3. The power splitting gear transmission device according to claim 2, characterized in that, The outer circle of the rear end of the elastic shaft (51) is provided with a first external thread (511), and the shaft hole at the rear end of the spline adapter sleeve (53) is provided with a first inner ring cavity and a second inner ring cavity arranged sequentially along the axial direction. The adjusting limit assembly (55) includes an adjusting limit nut (551) and a first elastic retaining ring (552). The rear end of the adjusting limit nut (551) is threaded to the first external thread through a connecting flange protruding along the center, and the front end of the adjusting limit nut (551) is installed in the second inner ring cavity through a first externally protruding shoulder. The first elastic retaining ring (552) is installed on the rear end of the spline adapter sleeve (53) and is locked in the first inner ring cavity so that the first shoulder is locked in the second inner ring cavity.

4. The power splitting gear transmission device according to claim 3, characterized in that, The shaft hole at the rear end of the split gear (54) is provided with a third inner ring cavity and a fourth inner ring cavity arranged sequentially along the axial direction; The adjusting limit assembly (55) also includes a toothed stop ring (553) that is slidably mounted in the fourth inner ring cavity along the axial direction, and a second elastic retaining ring (554) that is clamped in the third inner ring cavity. The toothed stop ring (553) is also fitted on the outer circle of the adjusting limit nut (551) to restrict the adjusting limit nut (551) from rotating in the circumferential direction. One side of the toothed stop ring (553) also abuts against the second elastic retaining ring (554) for limitation.

5. The power splitting gear transmission device according to claim 4, characterized in that, The outer ring surface of the toothed stop ring (553) is slidably connected to the bottom surface of the fourth inner ring cavity through the third spline pair (563). The inner ring surface of the toothed stop ring (553) is also provided with a plurality of outwardly protruding stop teeth (5531) arranged sequentially and circumferentially. The outer ring surface of the adjusting limit nut (551) is provided with multiple stop grooves (5511) corresponding to multiple stop teeth (5531). Each stop groove (5511) extends along the axial direction of the adjusting limit nut (551) to penetrate the rear end face of the adjusting limit nut (551).

6. The power splitting gear transmission device according to claim 3, characterized in that, The outer circle at the front end of the elastic shaft (51) is also provided with a second external thread, a fourth external spline, and a second protruding shoulder arranged sequentially along the axial direction; The inner shaft hole of the parallel gear (52) is provided with a fourth internal spline. The parallel gear (52) and the elastic shaft (51) are connected by the cooperation of the fourth internal spline and the fourth external spline to form a fourth spline pair (564) for sliding connection. The front end face of the inner cavity of the parallel gear (52) abuts against the second shoulder for limiting. A locking nut (57) is installed on the second external thread of the elastic shaft (51). The locking nut (57) abuts against the front end face of the parallel gear (52) to limit the parallel gear (52).

7. The power splitting gear transmission device according to claim 6, characterized in that, Let L2 be the distance between the front end face of the first external thread on the elastic shaft (51) and the front end face of the connecting flange on the adjusting limit nut (551); let L3 be the distance between the front end face of the first internal spline of the split gear (54) or the front end face of the second external spline of the elastic shaft (51) which is closer to the front end face of the spline adapter sleeve (53) and the front end face of the spline adapter sleeve (53); then L3≥L2; The difference between the minor diameter of the second and fourth external splines on the elastic shaft (51) and the outer diameter of the middle section located between the second and fourth external splines on the elastic shaft (51) is within ±0.02 mm.

8. A method of adjusting the load sharing coefficient of a power split gear transmission, characterized in that Using the power splitting gear transmission device as described in any one of claims 1-7, and assuming that the power splitting gear transmission device has only two power splitting branches (5), the load sharing coefficient adjustment method includes the following steps: Set the load-sharing factor η of the gear train: Formula 1; Torque calculation: Apply input torque multiple times and measure the torsion angle of the elastic shaft (51) on the two branches under each input torque, and then calculate the effective torsional stiffness value of the elastic shaft (51) in each branch, and obtain the specific value of the torque transmitted in the two branches. Substitution and Calculation Judgment: Substitute the specific values ​​of the torque transmitted by the two branches into Formula 1 to calculate the wheel system load sharing coefficient. If the wheel system load sharing coefficient meets the set target value, the operation terminates; otherwise, continue to the next step. Adjust the stiffness and recalculate: Adjust the position of the spline adapter sleeve (53) in the branch with the smaller specific value of the transmitted torque to increase the effective torsional stiffness of the elastic shaft (51) in the branch accordingly, and then re-input the torque to calculate the effective torsional stiffness value of the adjusted branch, and at the same time obtain the specific value of the transmitted torque of the two branches. Re-substitute the specific values ​​of the torque transmitted by the two branches into Formula 1 to calculate the wheel system load sharing coefficient. If the wheel system load sharing coefficient does not meet the set target value, continue the "adjust stiffness and recalculate" step for iterative calculation until the wheel system load sharing coefficient meets the set target value.

9. The method for adjusting the load sharing coefficient of the power splitting gear transmission device according to claim 8, characterized in that, The step "Applied Torque Calculation" specifically includes the following steps: S201: Let the effective torsional stiffness of the elastic shaft (51) on the first branch and the second branch at the initial position be respectively... k 1. k 2; S202: The output shaft of the fixedly connected output gear (3) applies input torque to the input shaft of the connected input gear (4). T 1. The torsion angle of the elastic shaft (51) on the first and second branches was obtained by measurement. θ 1-1 , θ 2-1 The first and second branch elastic shafts (51) transmit torques respectively. k 1 θ 1-1 , k 2 θ 2-1 It satisfies the following geometric relationship: Formula 2; in i The ratio of the number of teeth between the split gear (54) and the input gear (4); S203: Fix the output shaft and apply input torque to the input shaft. T 2, T 2. Take the torque of the gear transmission device under continuous long-term working conditions, and compare it with... T 1. The torsion angles of the elastic shafts (51) on the first and second branches are obtained by measurement. θ 1-2 , θ 2-2 The first and second branch elastic shafts (51) transmit torques respectively. k 1 θ 1-2 , k 2 θ 2-2 It satisfies the following geometric relationship: Formula 3; In Formulas 2 and 3, except k 1. k All other parameters except 2 are known values; by solving them together, we can obtain... k 1. k 2. This allows us to obtain the torque transmitted by the two branches. k 1 θ 1-2 , k 2 θ 2-2 The specific value.

10. The method for adjusting the load sharing coefficient of the power splitting gear transmission device according to claim 9, characterized in that, The step "adjusting stiffness and recalculating" specifically includes the following steps: S401: Calculate the load sharing coefficient of the gear train according to Formula 1. If the load sharing coefficient does not meet the set target value, compare the torque transmitted between the two branches. and The magnitude of the torque transmitted by the first branch is assumed to be less than that transmitted by the second branch; By increasing the effective torsional stiffness of the first branch elastic shaft (51), the transmitted torque of the first branch can be improved, making the transmitted torque of the two branches more balanced, thereby improving the load-sharing performance of the gear train. The required adjustment of the effective torsional stiffness of the first branch elastic shaft (51) can be initially calculated according to the following formula. : Formula 4; S402: To increase the effective torsional stiffness of the first branch elastic shaft (51), the adjusting limit nut (551) needs to be moved forward by Δ. The required axial movement distance Δ of the adjusting limit nut (551) is calculated using the following formula: Formula 5; S403: Fix the output shaft again and apply input torque to the input shaft. T 2. The torsion angle of the elastic shaft (51) on the first and second branches was obtained by measurement. θ 1-3 , θ 2-3 Assume that the effective torsional stiffness of the first branch elastic shaft (51) is at this time. Then the transmission of the elastic shafts (51) of the first and second branches are respectively , k 2 θ 2-3 It satisfies the following geometric relationship: Formula Six; It can be obtained through calculation. This allows us to obtain the torque transmitted by the two branches. , k 2 θ 2-3 The specific value.

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