Input shaft, multi-stage torque reducer and assembly method

Abstract

The present invention relates to the technical field of main reducer of helicopter transmission system, and specifically to an input shaft, a multi-stage torque reducer and an assembly method. The present invention comprises a body, one end of which is sequentially provided with a first spline and a second spline along the axial direction, the first spline is suitable for meshing with a first input bevel gear, and the second spline is suitable for meshing with an elastic shaft and then connected with a second input bevel gear. The input shaft of the present invention is the final link of the closed adjustment of the transmission chain of the multi-stage torque reducer. In the prior art, the input shaft is only provided with a section of spline, which is not easy to mesh at both ends and cannot be used as a closed link of the multi-stage torque transmission chain. The present invention is more convenient to install than the spline in the prior art. The two sections of spline are provided at one end, and only the appropriate angle needs to be adjusted to smoothly mesh with the first input bevel gear and the elastic shaft at the same time, so as to realize the closure of the multi-stage torque transmission chain, facilitate the assembly of the first and second input stage components and the main component, and at the same time, it is easy to realize the side clearance control of the transmission chain, and improve the load-sharing performance of the reducer.

Description

Technical Field

[0001] The invention relates to the technical field of speed reducers for helicopter transmission systems, and in particular to an input shaft, a multi-stage torque reducing reducer and an assembly method. Background Art

[0002] As the transmission configuration of the main reducer of the advanced helicopter transmission system, the split-torque transmission has the advantage of light weight under the same power transmission conditions. At present, many types of helicopters abroad have adopted the main reducer of the split-torque configuration. The split-torque transmission configuration is divided into single-stage split-torque transmission configuration and multi-stage split-torque transmission configuration.

[0003] The two major components (main component and input stage component) of the existing helicopter transmission system multi-stage torsion-split configuration main reducer are assembled in multiple rounds by adjusting the angular position of the transmission shaft between the main component and the input stage component, wherein the splines arranged on the input shaft are arranged at both ends of the input shaft, so that the probability of two sets of splines being engaged with the main component and the input stage component at the same time is very small, and the internal splines of the input stage component and the main component are both located inside the reducer casing, the assembly process is a blind assembly process, the spline side clearance is not easy to control, and the angular position of one of the transmission shafts needs to be adjusted multiple times, and multiple attempts are required to achieve assembly. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art that the assembly is complicated and the side clearance is difficult to control, thereby providing an input shaft, a multi-stage torque reducer and an assembly method.

[0005] In order to solve the above problems, the present invention provides an input shaft suitable for a multi-stage torque reducer, comprising:

[0006] A body, one end of which is provided with a first spline and a second spline in sequence along the axial direction, wherein the first spline is suitable for meshing with the first input bevel gear, and the second spline is suitable for meshing with the connecting shaft.

[0007] Optionally, the length of the first spline along the axial direction is not equal to the length of the second spline along the axial direction;

[0008] The minor diameter of the first spline is greater than the major diameter of the second spline;

[0009] The number of teeth of the first spline is not equal to the number of teeth of the second spline, and are coprime integers.

[0010] Optionally, the connecting shaft is an elastic shaft.

[0011] A multi-stage torque reducer comprises an input shaft.

[0012] Optionally, the first input bevel gear and the end of the connecting shaft close to each other are connected through a hole-shaft matching relationship, and a small gap is reserved between the two.

[0013] Optionally, it also includes a first driven bevel gear meshing with the first input bevel gear, the first driven bevel gear is connected to the main component, the first input bevel gear is also provided with a second input bevel gear through a connecting shaft and a spline shaft, the second input bevel gear is meshed with a second driven bevel gear, and the second driven bevel gear is connected to the main component.

[0014] Optionally, the main component comprises:

[0015] A first cylindrical gear is coaxially arranged with the first driven bevel gear or the second driven bevel gear, and the first cylindrical gear is meshed with second cylindrical gears on both sides thereof;

[0016] A third cylindrical gear, coaxially arranged with the second cylindrical gear;

[0017] The main gear is arranged on the main shaft and meshedly connected with the third cylindrical gear.

[0018] A method for assembling a multi-stage torque reducer, comprising:

[0019] Assembling the first input bevel gear and the first driven bevel gear to form a first input stage assembly;

[0020] Assembling the second input bevel gear and the second driven bevel gear to form a second input stage assembly;

[0021] Assemble the first cylindrical gear, the second cylindrical gear, the third cylindrical gear, the main gear, and the main shaft to form a main assembly;

[0022] Assembling the first input stage component, the second input stage component and the main component;

[0023] The angular position of the input shaft is adjusted until the second spline is connected to the second input bevel gear through the connecting shaft, and the first spline is connected to the first input bevel gear.

[0024] Optionally, the assembly method of the main component is specifically as follows:

[0025] Step 1: Mesh the third cylindrical gears simultaneously in the circumferential direction of the main gear;

[0026] Step 2: Install the second cylindrical gear coaxially arranged with the third cylindrical gear;

[0027] Step 3: Mesh the first cylindrical gear between two adjacent second cylindrical gears.

[0028] Optionally, the method of assembling the first input stage component and the second input stage component with the main component at the same time is specifically as follows:

[0029] The first driven bevel gear is coaxially connected to the first cylindrical gear, and the second driven bevel gear is coaxially connected to the first cylindrical gear.

[0030] The present invention has the following advantages:

[0031] 1. A spline shaft provided by the present invention has two sections of splines arranged in sequence at one end of the main body, the first spline can mesh with the first input bevel gear, the second spline meshes with the connecting shaft and then meshes with the second bevel gear, the input shaft is the final link of the closed adjustment of the multi-stage torque reducer transmission chain, in the prior art, the input shaft is only provided with one section of spline, and the splines are arranged at both ends in the prior art, which is not easy for both ends to mesh and cannot serve as a closed link of the multi-stage torque transmission chain, the present invention is more convenient to install than the splines arranged at both ends in the prior art, the two sections of splines are arranged at one end, and only the appropriate angle needs to be adjusted to smoothly mesh with the first input bevel gear and the elastic shaft at the same time, so as to realize the closure of the multi-stage torque transmission chain, facilitate the assembly of the first and second input stage components and the main component, and at the same time, it is easy to realize the side clearance control of the transmission chain, thereby improving the load-sharing performance of the reducer.

[0032] 2. The present invention provides a spline shaft, in which the first spline and the second spline simultaneously satisfy the following three conditions: the axial length of the first spline is not equal to the axial length of the second spline; the minor diameter of the first spline is larger than the major diameter of the second spline; the number of teeth of the first spline is not equal to the number of teeth of the second spline, and are mutually prime integers. This ensures that the input shaft can be smoothly meshed and connected with the first input bevel gear and the connecting shaft.

[0033] 3. The present invention provides a multi-stage torque-split reducer, in which the first input bevel gear and the end of the connecting shaft that are close to each other have clearance fit, the input shaft transmits power to the first input bevel gear and the second input bevel gear, the first input bevel gear and the second input bevel gear respectively transmit power to the first driven bevel gear and the second driven bevel gear, and then drive the first cylindrical gear to rotate, the first cylindrical gear transmits power to the second cylindrical gears on the left and right sides to realize power diversion and reduce the torque transmitted by the gear pair, the second cylindrical gear and the third cylindrical gear are coaxially arranged as a group of gear sets, and a total of eight groups of parallel gear sets are arranged, all of which are meshed around the main gear under the main shaft. The reducer has a large transmission ratio, light weight and strong load-bearing capacity; the transmission mechanism has a compact structure and is easy to process; the power is diverted in multiple ways, and the torque transmitted by the gears in each branch is reduced, which improves the load-bearing capacity and fatigue life of the gears, and at the same time makes the transmission system have higher survivability.

[0034] 4. The assembly method of a multi-stage torque-split reducer provided by the present invention is compared with the existing assembly process of a certain type of multi-stage torque-split transmission. In this technical solution, the final closed link of the assembly is the assembly of the input shaft. In this assembly solution, since the angular position of the front input stage and the rear input stage gears are free, the two input stages and the main component transmission chain do not form a closed chain, so the adjustment of the angular position of the transmission shaft between the two and the trial assembly process are eliminated during the assembly process of the input stage assembly and the main component, and the assembly process is greatly simplified. At the same time, after the assembly of the input stage and the main component is completed, effective measures can be taken to eliminate the side clearance between the front input stage-main component and the rear input stage-main component transmission chain, and then the single-sided double spline input shaft is installed to close the entire transmission chain to complete the main reduction assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic structural diagram of an input shaft, a first input bevel gear and a connecting shaft provided by the present invention are shown;

[0037] Figure 2 A schematic structural diagram of an input shaft provided by the present invention is shown;

[0038] Figure 3 The schematic diagram of the structure of a multi-stage torque reducer provided by the present invention is shown.

[0039] Description of reference numerals:

[0040] 1. First spline; 2. Second spline; 3. Elastic shaft; 4. First input bevel gear; 5. Second input bevel gear; 6. Second driven bevel gear; 7. First driven bevel gear; 8. First cylindrical gear; 9. Second cylindrical gear; 10. Third cylindrical gear; 11. Main shaft; 12. Main gear. DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0043] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] Example 1

[0046] This embodiment provides an input shaft suitable for a multi-stage torque reducer.

[0047] In one embodiment, Figure 1-Figure 2 As shown, the input shaft comprises: a body, one end of which is provided with a first spline 1 and a second spline 2 in sequence along the axial direction, the first spline 1 is suitable for meshing with the first input bevel gear 4, and the second spline 2 is suitable for meshing with the connecting shaft.

[0048] Specifically, by sequentially arranging two sections of splines at one end of the main body, that is, the splines at both ends are arranged closely, the first spline 1 can mesh with the first input bevel gear 4, and the second spline 2 can mesh with the connecting shaft. In the prior art, the splines are arranged at both ends, which makes it difficult for both ends to mesh. The present invention is more convenient to install than the prior art in which the splines are arranged at both ends. The splines at both ends are arranged at one end only by adjusting the appropriate angular direction to smoothly mesh with the first input bevel gear 4 and the connecting shaft at the same time. The input stage assembly and the main assembly can also be conveniently assembled in the inner box, which makes it easy to realize the side clearance control of the transmission chain and improve the load-sharing performance of the reducer.

[0049] On the basis of the above embodiments, in a preferred embodiment, the spline meets the following conditions: the length of the first spline 1 along the axial direction is not equal to the length of the second spline 2 along the axial direction; the minor diameter of the first spline 1 is greater than the major diameter of the second spline 2, that is, the inner ring diameter of the first spline 1 is greater than the outer ring diameter of the second spline 2; the number of teeth of the first spline 1 is not equal to the number of teeth of the second spline 2, and they are mutually prime integers, that is, the number of teeth of the first spline 1 and the number of teeth of the second spline 2 have no other common divisors except 1. In this way, it can be ensured that the input shaft is smoothly meshed and connected with the first input bevel gear and the connecting shaft.

[0050] The material of the connecting shaft is not specifically limited, and it can be an elastic shaft made of elastic material.

[0051] Example 2

[0052] This embodiment provides a multi-stage torque-split reducer, comprising two input shafts provided in the above embodiments, two sets of input stage components and four sets of main components.

[0053] On the basis of the above-mentioned embodiment, in a preferred embodiment, as Figure 1 As shown, the first input bevel gear 4 and the end of the connecting shaft close to each other are sleeved and connected, and a gap is reserved between the two. Specifically, the end of the connecting shaft is sleeved on the end of the first input bevel gear 4.

[0054] On the basis of the above-mentioned embodiment, in a preferred embodiment, the multi-stage torque-split reducer further includes a first driven bevel gear 7 meshingly connected with the first input bevel gear 4, the first driven bevel gear 7 is transmission-connected with a group of main components, the main components are transmission-connected with the main shaft 11, the first input bevel gear 4 is also provided with a second input bevel gear 5 through a connecting shaft, the second input bevel gear 5 is meshed with a second driven bevel gear 6, the second driven bevel gear 6 is transmission-connected with another group of main components, and the main components are transmission-connected with the main shaft 11. The axes of the first driven bevel gear 7 and the first input bevel gear 4 are perpendicular to each other, the axes of the second driven bevel gear 6 and the second input bevel gear 5 are perpendicular to each other, and the axes of the first driven bevel gear 7 and the second driven bevel gear 6 are parallel to each other. The first driven bevel gear 7, the first input bevel gear 4, the second driven bevel gear 6 and the second input bevel gear 5 form a group of input stage components, and another group of input stage components is symmetrically arranged with respect to the main shaft 11 with respect to the group of input stage components.

[0055] On the basis of the above embodiments, in a preferred embodiment, the main component includes:

[0056] The first cylindrical gear 8 is coaxially arranged with the first driven bevel gear 7, and the second cylindrical gears 9 are respectively meshed on both sides of the first cylindrical gear 8;

[0057] A third cylindrical gear 10 is coaxially arranged with the second cylindrical gear 9;

[0058] The main gear 12 is disposed on the main shaft 11 and meshed with the third cylindrical gear 10 .

[0059] Four groups of main components are arranged at equal intervals around the outside of the main shaft 11.

[0060] Specifically, the first input bevel gear 4 and the end of the connecting shaft close to each other are clearance-fitted, and the input shaft transmits power to the first input bevel gear 4 and the second input bevel gear 5, and the first input bevel gear 4 and the second input bevel gear 5 transmit power to the first driven bevel gear 7 and the second driven bevel gear 6 respectively, and then drive the first cylindrical gear 8 to rotate, and the first cylindrical gear 8 transmits power to the second cylindrical gear 9 on the left and right sides to realize power diversion and reduce the torque transmitted by the gear pair, and the second cylindrical gear 9 and the third cylindrical gear 10 are coaxially arranged as a group of gear sets, and a total of eight groups of parallel gear sets are arranged, all of which are meshed around the main gear 12 under the main shaft 11. The reducer has a large transmission ratio, light weight and strong load-bearing capacity; the transmission mechanism has a compact structure and is easy to process; the power is diverted in multiple ways, and the torque transmitted by the gears in each branch is reduced, which improves the load-bearing capacity and fatigue life of the gears, and at the same time makes the transmission system have higher survivability.

[0061] Example 3

[0062] This embodiment provides an assembly method for a multi-stage torque reducer, and the assembly steps are as follows:

[0063] Step 1: Assemble the first input bevel gear 4 and the first driven bevel gear 7 to form a first input stage assembly;

[0064] Assemble the second input bevel gear 5 and the second driven bevel gear 6 to form a second input stage assembly;

[0065] Step 2: Assemble the main components. The specific assembly method is:

[0066] Eight third cylindrical gears 10 are meshed in the circumferential direction of the main gear 12;

[0067] Install a second cylindrical gear 9 coaxially arranged with the third cylindrical gear 10;

[0068] The first spur gear 8 meshes with two adjacent second spur gears 9 .

[0069] Step 3: Assemble the input stage components and the main components. The specific method is as follows:

[0070] By arranging a shaft above the first driven gear 7 , the second driven bevel gear 6 is coaxially connected to the first cylindrical gear 8 .

[0071] Step 4: Install the second input bevel gear 5 on one end of the connecting shaft, adjust the angular position of the input shaft until the second spline 2 of the input shaft is engaged with the connecting shaft, and the first input bevel gear 4 is engaged with the first spline 1 of the input shaft, and the assembly is completed.

[0072] In the above-mentioned whole assembly process, the double spline shaft is installed last, which is the last closed link of the whole transmission chain, and the two external splines of the input shaft are meshed with the first input bevel gear 4 and the internal splines of the elastic shaft respectively. Compared with the existing assembly process of a certain type of multi-stage torque transmission, the last closed link of the assembly of this embodiment is the assembly of the input shaft. In this assembly scheme, since the angular position of the front input stage and the rear input stage gears are free, the two input stages and the main component transmission chain do not form a closed chain, so the angular position adjustment and trial assembly process of the transmission shaft between the two are eliminated during the assembly process of the input stage assembly and the main component, and the assembly process is greatly simplified. At the same time, after the assembly of the input stage and the main component is completed, effective measures can be taken to eliminate the side clearance between the front input stage-main component and the rear input stage-main component transmission chain, and then the single-sided double spline input shaft is installed to close the whole transmission chain and complete the main reduction assembly.

[0073] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A multi-stage torque reducer, characterized in that: The multi-stage torque-split reducer comprises an input shaft, the input shaft comprises a body, one end of the body is provided with a first spline (1) and a second spline (2) in sequence along the axial direction, the first spline (1) is suitable for meshing with a first input bevel gear (4), and the second spline (2) is suitable for meshing with a connecting shaft (3); the length of the first spline (1) along the axial direction is not equal to the length of the second spline (2) along the axial direction; the minor diameter of the first spline (1) is greater than the major diameter of the second spline (2); the number of teeth of the first spline (1) is not equal to the number of teeth of the second spline (2), and they are mutually prime integers; The multi-stage torque splitter reducer further comprises a first driven bevel gear (7) meshingly connected to the first input bevel gear (4), the first driven bevel gear (7) being connected to a main component, the first input bevel gear (4) being further provided with a second input bevel gear (5) via a connecting shaft (3) and a spline shaft, the second input bevel gear (5) being meshingly connected to a second driven bevel gear (6), the second driven bevel gear (6) being connected to the main component.

2. The multi-stage torque reducer according to claim 1, characterized in that: The connecting shaft (3) is an elastic shaft.

3. The multi-stage torque reducer according to claim 1, characterized in that: The first input bevel gear (4) and the end of the connecting shaft that is close to each other are connected through a hole-shaft matching relationship, and a small gap is reserved between the two.

4. The multi-stage torque reducer according to claim 1, characterized in that: The main components include: A first cylindrical gear (8) is coaxially arranged with the first driven bevel gear (7) or the second driven bevel gear (6), and second cylindrical gears (9) are respectively meshed on both sides of the first cylindrical gear (8); A third cylindrical gear (10) is coaxially arranged with the second cylindrical gear (9); A main gear (12) is disposed on the main shaft (11) and is meshedly connected with the third cylindrical gear (10).

5. A method for assembling a multi-stage torque reducer, using the multi-stage torque reducer according to claim 4, characterized in that: include: Assembling the first input bevel gear (4) and the first driven bevel gear (7) to form a first input stage assembly; Assembling the second input bevel gear (5) and the second driven bevel gear (6) to form a second input stage assembly; Assembling the first cylindrical gear (8), the second cylindrical gear (9), the third cylindrical gear (10), the main gear (12), and the main shaft (11) to form a main assembly; Assembling the first input stage component, the second input stage component and the main component; The angular position of the input shaft is adjusted so that the second spline (2) is connected to the second input bevel gear (5) via the connecting shaft, and the first spline (1) is connected to the first input bevel gear (4).

6. The assembly method of a multi-stage torque reducer according to claim 5, characterized in that: The assembly method of the main component is specifically as follows: Step 1: Meshing eight third cylindrical gears (10) simultaneously in the circumferential direction of the main gear (12); Step 2: Install the second cylindrical gear (9) coaxially arranged with the third cylindrical gear (10); Step 3: The first cylindrical gear (8) is meshed between two adjacent second cylindrical gears (9).

7. The assembly method of a multi-stage torque reducer according to claim 6, characterized in that: The method of assembling the first input stage component and the second input stage component with the main component at the same time is specifically as follows: The first driven bevel gear (7) is coaxially connected to the first cylindrical gear (8), and the second driven bevel gear (6) is coaxially connected to the first cylindrical gear (8).

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