A method for gear pairing of an NGWN planetary gear

Abstract

The application relates to a NGWN planetary gear pairing method, which comprises the following steps: firstly, designing the first-stage planetary gear parameters according to the size and weight requirements, judging whether the abutment and installation conditions are met, calculating the uniform distribution misalignment angle of the two-stage planetary gears and the tooth misalignment angle of the double planetary gears, judging whether the second-stage planetary gears meet the abutment condition, the concentric condition and the installation condition, and further determining whether the designed NGWN planetary gears meet the transmission ratio condition. The method solves the problems of the existing NGWN planetary gear transmission pairing difficulty, gear interference, large vibration and noise and the like.

Description

Technical Field

[0001] This invention belongs to the field of mechanical assembly technology, specifically relating to the gear matching design method of NGWN type planetary gear transmission. Background Technology

[0002] The NGWN type planetary gear transmission mechanism is a mechanical device that transmits motion or power. This device has the advantages of large transmission ratio, high efficiency, small size and compact structure, and is widely used in gear rotary actuators in aircraft, ships, automobiles and other fields.

[0003] In the past 20 years, relevant mechanical design manuals in my country have emphasized that, when discussing the selection of basic parameters for planetary gear transmissions, in addition to requiring that the selection principles for the number of teeth of involute cylindrical gears and the conditions for tooth strength be met, the number of teeth of the central gear and the number of planetary gears should also meet four basic conditions: transmission ratio condition, assembly condition, adjacency condition, and concentricity condition.

[0004] In planetary gear transmission design, in order to obtain a larger transmission ratio, NGWN planetary gear transmission design with a small tooth difference is usually selected. Since the difference in the number of teeth between the first stage and the second stage planetary gears and gear rings is usually 1 to 2 teeth, and may be more in special application scenarios, this results in the second stage having very few or even no suitable tooth matching parameters when the first stage meets the assembly and adjacency conditions, making tooth matching difficult.

[0005] In current aerospace rotary actuators, most choose NGWN-type planetary gear transmission designs. There are few methods for matching the teeth of this complex planetary gear. Most current tooth matching patents are for NGW-type planetary gear designs. The design methods for NGWN-type planetary gears are mostly limited to the sum of the number of teeth of the sun gear and the ring gear being an integer multiple of the number of planet gears. Moreover, some tooth matching methods are difficult to operate and have not been developed into software interfaces. Compared with NGW-type planetary gears, NGWN-type planetary gears have a larger transmission ratio and stronger load-bearing capacity within the same structural space, and the corresponding tooth matching is more difficult.

[0006] Among the publicly disclosed gear matching technologies, patent CN101216090 discloses a gear matching method for planetary gear transmissions, thereby solving the problems of difficulty in gear matching, insufficient and unreasonable basis, and large vibration and noise in existing planetary gear transmission gear matching technologies. The gear matching method of this patent includes the following steps: (1) determining the theoretical transmission ratio according to the design conditions; (2) determining the number of teeth of the central gear and the number of planetary gears; (3) judging whether the basic assembly conditions are met; (4) correcting the number of teeth of the central gear according to the different requirements of the transmission system application; (5) further correcting the number of teeth of the planetary gears according to the number of teeth of the central gear, and obtaining the proposed transmission ratio; (6) judging whether the proposed transmission ratio meets the design requirements. If it meets the requirements, proceed to the next step; otherwise, return to step (2); (7) perform vibration characteristic analysis of the system to determine whether there is harmonic resonance at a given speed. If harmonic resonance occurs, return to step (2); otherwise, take the above gear matching scheme as the final result. This patent belongs to the gear matching method of planetary gear transmissions and is only applicable to the gear matching of NGW planetary gears.

[0007] Patent CN103246775A discloses a gear matching design method for a torque-split transmission gear system, addressing the technical problem of poor operability in existing design methods. The technical solution first establishes unified gear matching conditions; then, based on the gear matching formula, it provides a list of all tooth number combinations and installation angles; next, it determines the tooth number combinations and installation angles based on the initially determined transmission ratios of each gear stage; then, it determines the module of each gear stage based on strength checks and geometric constraints; finally, it verifies the correctness of the design results using the formula for the gear matching conditions, and checks for interference between the gear teeth and the gear body through precise drawing. This method is highly operable. This patented technology determines whether a gear meets the design assembly conditions and strength requirements based on known gear parameters; however, it is not applicable to the gear structure of NGWN planetary gears. Summary of the Invention

[0008] The purpose of this invention is to design a gear matching method suitable for NGWN planetary gears, which reduces the difficulty of gear matching and improves the efficiency of gear matching.

[0009] The technical solution of this invention is: an NGWN planetary gear matching method. The method first designs the parameters of the first-stage planetary gear according to the size and weight requirements, determines whether the adjacency and installation conditions are met, calculates the uniformly distributed misalignment angle of the two-stage planetary gears and the tooth misalignment angle of the double-linked planetary gears, determines whether the second-stage planetary gear meets the adjacency, concentricity and installation conditions, and then determines whether the designed NGWN planetary gear meets the transmission ratio conditions.

[0010] Preferably, the method for calculating the uniformly distributed misalignment angle of the two-stage planetary gears and the tooth misalignment angle of the double planetary gears is based on the following formula:

[0011] Planetary gears are evenly distributed with a misalignment angle α均布 =1 / n*δ*(360 / z) c )

[0012] Planetary gear tooth misalignment angle α 齿数 =(1 / z) c -1 / z d )*360

[0013] In the formula, n is the number of planetary gears, δ is the difference in the number of teeth between the front and rear stages of the planetary gear, and z c z is the number of teeth on the first-stage planetary gear. d This represents the number of teeth on the second-stage planetary gear.

[0014] Preferably, in the above gear matching method, when determining whether the second-stage planetary gear meets the adjacency condition, concentricity condition, and installation condition, an arbitrary difference δ between the number of teeth of the preceding and following stages of the planetary gear is pre-set. A gear matching scheme that meets the gear matching conditions is obtained through calculation and matching. The judgment / calculation process is as follows: First, it is determined whether the uniformly distributed misalignment angle is an integer multiple of the tooth misalignment angle when the difference between the number of teeth of the preceding and following stages of the planetary gear is δ. If so, it is then determined whether the parameters of the second-stage planetary gear meet the concentricity, adjacency, and assembly conditions. Otherwise, it is continued to determine whether the concentricity, adjacency, and assembly conditions are met when the difference between the number of teeth of the preceding and following stages of the planetary gear is δ-1, until δ=1. If none of the conditions are met, the design parameters of the first-stage gear need to be modified.

[0015] Preferably, the criteria for determining whether the first-stage NGW planetary gear meets the adjacency and installation conditions are as follows:

[0016] Adjacency condition: 2×r ac <L c

[0017] d ac <2×a ac sin(π / n)

[0018] Installation conditions: (Za+Zb) / n=C1

[0019] C1 is an integer.

[0020] Preferably, this method, by understanding the assembly principle of NGWN type planetary gears, proposes a gear matching method that can be implemented in code and compiled into gear matching software. The software calculates the uniform misalignment angle of the double-toothed planetary gears during gear ring assembly and the tooth misalignment angle of the double-toothed planetary gears, determines whether the planetary gears meet the gear matching conditions, and outputs the gear matching results.

[0021] Preferably, the transmission ratio of the NGWN planetary gears can be calculated to further determine whether the matched NGWN planetary gears meet the transmission ratio requirements; the transmission ratio of the NGWN planetary gears is (output of the second-stage gear ring):

[0022]

[0023] Preferably, the tooth matching method can also match tooth (Za+Ze) / n when it is not an integer.

[0024] The beneficial effects of this invention are as follows: 1. It has a sound theoretical basis. The gear matching method of this invention fully meets the concentricity conditions, installation conditions, adjacency conditions, and transmission ratio conditions required in the gear transmission design manual, and the calculation results are accurate. 2. The gear matching method of this invention is easy to implement with software. Using the designed software, one only needs to design the parameters of the first-stage planetary gear, input them into the software, calculate the planetary gear parameters that meet the conditions within five tooth differences, and output the results. 3. The gear matching efficiency of this invention is high, improving efficiency by more than 50% compared with the traditional manual gear matching method. 4. The method proposed in this invention can be implemented through programming software. Using the corresponding design software, it can match the cases where the sum of the number of teeth of the sun gear and planet gears of a certain stage of NGWN type planetary gear divided by the number of planet gears is not an integer. Finally, precise drawing is used to check for interference between the gear teeth and the gear body, making it highly operable. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the tooth fitting design process of the present invention;

[0026] Figure 2 This is a schematic diagram of the adjacency conditions of the NGWN type planetary gear of the present invention;

[0027] Figure 3 This is an interference check diagram showing the results of the NGWN type planetary gear matching method of the present invention. Detailed Implementation

[0028] The following is combined Figures 1-3 This document details the specific implementation process of this gear fitting method.

[0029] An NGWN planetary gear matching method is disclosed. The method includes the following steps: (1) Determine the parameters of the first-stage NGW planetary gear and the number of planetary gears according to the size and weight requirements of the planetary gears and input them into the software; (2) Determine whether the first-stage NGW planetary gears meet the adjacency conditions and installation conditions; (3) Within a range of 5 teeth difference in the number of planetary gears, calculate the uniformly distributed misalignment angle of the two-stage planetary gears and the tooth misalignment angle of the double-linked planetary gears according to the formula; (4) Determine whether the uniformly distributed misalignment angle is an integer multiple of the tooth misalignment angle. If not, return to the first step for redesign; (5) Determine whether the second-stage planetary gears meet the adjacency conditions, concentricity conditions, and installation conditions. If not, return to the first step for redesign; (6) Determine whether the NGWN planetary gear transmission ratio meets the requirements. If it does, output the result; if not, return to the first step for redesign; Finally, check whether there is any interference between the gear teeth and the gear body by precise drawing. The method is highly operable.

[0030] Specifically, the calculation method for the uniformly distributed misalignment angle of the two-stage planetary gears and the tooth misalignment angle of the double planetary gears is based on the formula, which is as follows:

[0031] Planetary gears are evenly distributed with a misalignment angle α 均布 =1 / n*δ*(360 / z) c )

[0032] Planetary gear tooth misalignment angle α 齿数 =(1 / z) c -1 / z d )*360

[0033] In the formula, n is the number of planetary gears, δ is the difference in the number of teeth between the front and rear stages of the planetary gear, and z c z is the number of teeth on the first-stage planetary gear. d This represents the number of teeth on the second-stage planetary gear.

[0034] Specifically, in the above gear matching method, when determining whether the second-stage planetary gear meets the adjacency, concentricity, and installation conditions, an arbitrary difference δ between the number of teeth of the preceding and following stages of the planetary gear is pre-set. A gear matching scheme that meets the matching conditions is obtained through calculation and matching. The judgment / calculation process is as follows: First, it is determined whether the uniformly distributed misalignment angle is an integer multiple of the tooth misalignment angle when the difference between the number of teeth of the preceding and following stages of the planetary gear is δ. If so, it is then determined whether the parameters of the second-stage planetary gear meet the concentricity, adjacency, and assembly conditions. Otherwise, it is continued to determine whether the concentricity, adjacency, and assembly conditions are met when the difference between the number of teeth of the preceding and following stages of the planetary gear is δ-1, until δ = 1. If none of the conditions are met, the design parameters of the first-stage gear need to be modified.

[0035] Specifically, the criteria for determining whether the first-stage NGW planetary gear meets the adjacency and installation conditions are as follows:

[0036] Adjacency condition: 2×r ac <L c

[0037] d ac <2×a ac sin(π / n)

[0038] Installation conditions: (Za+Zb) / n=C1

[0039] C1 is an integer.

[0040] This method, based on an understanding of the assembly principle of NGWN-type planetary gears, proposes a gear matching method that can be implemented in code and compiled into gear matching software. The software calculates the uniform misalignment angle of the double-toothed planetary gears during gear ring assembly and the tooth misalignment angle of the double-toothed planetary gears, determines whether the planetary gears meet the gear matching conditions, and outputs the gear matching results.

[0041] The following example illustrates the gear matching design of a certain type NGWN planetary gear. Based on the above design concept, gear matching software was developed; the specific execution process is as follows:

[0042] 1) Start the software;

[0043] 2) Based on size and weight requirements, design an NGWN type planetary gear with the following first-stage tooth counts: Za = 46, Zb = 90, Zc = 22; module m = 1.25; number of planetary gears n = 8; and addendum coefficient ha = 1. Figure 2 The method shown determines whether the first-stage planetary gears meet the adjacency and installation conditions.

[0044] 3) The software can automatically calculate the planetary gear misalignment angle between the first and second stage planetary gears, and the tooth misalignment angle between planetary gears Zc and Zd, when the difference between the number of teeth of the second stage planetary gear Zd and the number of teeth of the first stage planetary gear Zc is within 5.

[0045] Planetary gears are evenly distributed with a misalignment angle α 均布 = 1 / n * (|Zc - Zd|) * (360 / z) c )

[0046] Planetary gear tooth misalignment angle α 齿数 =(1 / z) c -1 / z d )*360

[0047] 4) If the uniformly distributed misalignment angle of the planetary gears is an integer multiple of the tooth misalignment angle of planetary gears Zc and Zd, further determine whether the second-stage planetary gears meet the adjacency condition, concentricity condition, and installation condition.

[0048] 5) Calculate the NGWN planetary gear transmission ratio for this design;

[0049] The NGWN planetary gear transmission ratio for this type of gear (second stage gear ring output) is:

[0050]

[0051] 6) If the transmission ratio also meets the requirements, the gear matching is complete, and the output teeth are Za, Zb, Zc, Zd, Ze, module m, and number of planetary gears n.

[0052] 7) Draw the assembly drawing in 2D software and check whether the gear matching scheme interferes.

[0053] It should be noted that the above description is only a preferred embodiment of the present invention; any part not described in detail is considered to be prior art or conventional implementation means; it should also be noted that for those skilled in the art, several modifications and improvements can be made without departing from the principle of the present invention, and these should also be considered to fall within the protection scope of the present invention.

Claims

1. A method for matching gears in an NGWN planetary gear system, characterized in that, The method first designs the parameters of the first-stage planetary gears based on size and weight requirements, determines whether the adjacency and installation conditions are met, calculates the uniform misalignment angles of the two-stage planetary gears and the tooth misalignment angles of the double-planetary gears, and then determines whether the second-stage planetary gears meet the adjacency, concentricity, and installation conditions. Finally, it determines whether the designed NGWN-type planetary gears meet the transmission ratio requirements. The calculation method for the uniform misalignment angles of the two-stage planetary gears and the tooth misalignment angles of the double-planetary gears is obtained using the following formula. Planetary gears are evenly distributed with a misalignment angle α 均布 =1 / n*δ*(360 / z c ) Planetary gear tooth misalignment angle α 齿数 =(1 / z c -1 / z d )*360 In the formula, n is the number of planetary gears, δ is the difference in the number of teeth between the front and rear stages of the planetary gear, and z c z is the number of teeth on the first-stage planetary gear. d This represents the number of teeth on the second-stage planetary gear. When determining whether the second-stage planetary gear meets the adjacency, concentricity, and installation conditions, an arbitrary difference δ between the number of teeth of the preceding and following stages of the planetary gear is pre-set. A matching scheme that meets the matching conditions is obtained through calculation. The judgment / calculation process is as follows: First, it is determined whether the uniformly distributed misalignment angle is an integer multiple of the tooth misalignment angle when the difference between the number of teeth of the preceding and following stages of the planetary gear is δ. If so, it is then determined whether the parameters of the second-stage planetary gear meet the concentricity, adjacency, and assembly conditions. Otherwise, it is continued to determine whether the concentricity, adjacency, and assembly conditions are met when the difference between the number of teeth of the preceding and following stages of the planetary gear is δ-1, until δ=1. If none of the conditions are met, the design parameters of the first-stage gear need to be modified.

2. The NGWN planetary gear matching method as described in claim 1, characterized in that, Set the difference in the number of teeth between the front and rear stages of the planetary gear to δ=5.

3. The NGWN planetary gear matching method as described in claim 1, characterized in that, The criteria for determining whether the first-stage NGW planetary gear meets the adjacency and installation conditions are as follows: Adjacency conditions: 2×r ac <L c d ac <2×a ac sin(π / n) Installation requirements: （z a +z b ) / n=C1 C1 is an integer.

4. The NGWN planetary gear matching method as described in claim 1, characterized in that, Calculate the NGWN planetary gear transmission ratio to further determine whether the matched NGWN planetary gears meet the transmission ratio requirements; the NGWN planetary gear transmission ratio is: 。 5. The NGWN planetary gear matching method as described in claim 1, characterized in that, The gear matching method can be implemented in code and compiled into gear matching software. The software calculates the uniform misalignment angle of the double-toothed planetary gears during gear ring assembly and the tooth misalignment angle of the double-toothed planetary gears, determines whether the planetary gears meet the gear matching conditions, and outputs the gear matching results.

6. The NGWN planetary gear matching method as described in claim 5, characterized in that, The tooth fitting method can also fit teeth (z) a +z e The case where ) / n is not an integer.

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