Aviation staggered herringbone gear grinding process parameter design method

Abstract

The invention belongs to the technical field of aviation gear machining and the field of grinding processes, and relates to an aviation staggered herringbone gear grinding process parameter design method. The staggered herringbone gear comprises a left bevel gear, a middle clearance groove and a right bevel gear; the left helical gear and the right helical gear have the same helical angle beta and normal modulus mn, and the left helical gear and the right helical gear are staggered by a staggered angle theta; the method comprises the following steps: 1, calculating a judgment parameter K according to a judgment formula; 2, whether the value of the parameter K is in a first value range (Ka, Kb) or not is judged, and if yes, it is judged that borrowing grinding can be conducted, and the grinding wheel can obtain the maximum diameter Dmax; otherwise, determining non-borrowing grinding; and 3, the maximum diameter Dmax of the grinding wheel is calculated.

Description

Technical Field

[0001] This invention belongs to the fields of aerospace gear processing technology and grinding technology, and relates to a method for designing process parameters for grinding aerospace misaligned herringbone gears. This method is used to accurately determine the maximum diameter of the grinding wheel that meets the grinding requirements of aerospace misaligned herringbone gears, thereby ensuring grinding accuracy and efficiency. Background Technology

[0002] In the field of aerospace manufacturing, herringbone gears are key transmission components, and their machining accuracy significantly affects the operational reliability and transmission efficiency of aerospace equipment. Grinding is the core process to ensure their accuracy, and the proper determination of the grinding wheel diameter parameters is crucial.

[0003] Traditional methods for determining grinding wheel diameter have many drawbacks, making it difficult to meet the high-precision requirements of grinding complex tooth profiles. This often leads to problems such as insufficient grinding accuracy, uneven wheel wear, and low processing efficiency. While advanced manufacturing technologies have offered new approaches in recent years, such as mathematical modeling and CAE (Computer-Aided Engineering) technology, existing methods for determining grinding wheel diameters for grinding aerospace misaligned herringbone gears still have shortcomings. On the one hand, the analysis of the coupling relationship between gear tooth misalignment characteristics, complex meshing motion, and grinding wheel diameter is insufficient, making it difficult for the model's accuracy to meet the demands of high-precision grinding. On the other hand, the lack of a multi-factor synergistic consideration system fails to fully integrate tooth profile accuracy requirements, grinding process constraints, and equipment performance limitations. Consequently, the determined maximum grinding wheel diameter may fail to balance processing accuracy and efficiency in practical applications, or it may be difficult to adapt to the production environment, affecting grinding quality and production cycle time. Summary of the Invention

[0004] Purpose of the invention: To address the problems of insufficient model accuracy, lack of multi-factor collaborative consideration, and difficulty in balancing machining accuracy and efficiency in existing methods for determining the diameter of grinding wheels for aerospace misaligned herringbone gears, this invention provides a method for designing process parameters for grinding aerospace misaligned herringbone gears. This method enables the expansion of grinding wheel size or the reduction of the empty groove width, improving grinding quality and efficiency, and facilitating weight reduction design of aerospace misaligned herringbone gears and their systems. Technical solution: A method for designing grinding process parameters for aerospace misaligned herringbone gears, wherein the misaligned herringbone gear includes a left helical gear, a central empty groove, and a right helical gear; the left and right helical gears have the same helix angle β and normal module mn, and are misaligned, denoted by a misalignment angle θ; the method steps are as follows: Step 1: Calculate the judgment parameter K according to the judgment formula; Step 2: Determine whether the value of parameter K is within the first value range (Ka, Kb). If it is, it is determined that it is a grinding process that can be borrowed and the grinding wheel can obtain the maximum diameter Dmax; otherwise, it is determined that it is a grinding process that cannot be borrowed. Step 3: Calculate the maximum diameter Dmax of the grinding wheel.

[0005] Furthermore, the determination formula is as follows:

[0006] L is the width of the herringbone gear cutter groove. This is the misalignment angle coefficient, whose value is related to the misalignment angle. In this literature, the value is 1 / 2.

[0007] Furthermore, the method also includes step zero: determining whether the helix angle β is greater than 35°. If so, it is directly determined that it is non-misaligned grinding and the method ends; otherwise, step one is executed.

[0008] Furthermore, in step two, if the helix angle β is less than 15°, then Ka = 0 and Kb = 0.25.

[0009] Furthermore, in step two, when the helix angle β is in the range of [15°, 35°], Ka = 0.75 and Kb = 1.25.

[0010] Furthermore, in step two, if it is non-borrowing grinding, then determine whether K is within the range of (0.25, 0.75). If so, then determine whether there is interference between the opposite teeth.

[0011] Furthermore, in step two, if it is non-borrowing grinding, then determine whether K is within the range of (1.25, 1.75). If so, then determine whether the adjacent teeth on the opposite side are interfering.

[0012] Furthermore, the Dmax calculation process is as follows:

[0013] Intermediate substitution quantity is , ; Φu is the addendum circle diameter of the gear being machined, Φd is the root circle diameter of the gear being machined, h=0.5 (Φu—Φd);

[0014] Where L is the width of the herringbone gear cutter groove, Ru=0.5Φu is the addendum circle radius, β is the helix angle, Z is the number of teeth, and h=0.5(Φu—Φd) is the tooth height;

[0015] Substitute the parameters into the formula to calculate:

[0016] Intermediate substitution quantity is , :

[0017] in

[0018] The intermediate substitution quantities ∠fcf′, df′, ∠ne'e are as follows:

[0019] Where Su is the tooth thickness of the tooth tip arc, w is the tooth width, and Rm is the pitch circle radius.

[0020] Beneficial effects: 1. It can quantitatively identify the misalignment conditions and effects of existing aerospace gears, providing a scientific basis for the parameter design of misalignable grinding.

[0021] 2. By rationally designing the misalignment angle θ, the grinding wheel size can be expanded or the width of the empty groove can be reduced, which is beneficial to improving grinding quality and efficiency.

[0022] 3. It can reduce the weight of individual components and systems of misaligned herringbone gears used in aviation, meeting the requirements for lightweight aviation equipment.

[0023] 4. Targeted judgments are made for different helix angle ranges and tooth counts, which improves the applicability and accuracy of the method.

[0024] 5. It can predict in advance whether interference will occur, avoid malfunctions during the grinding process, and ensure smooth processing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the misaligned adjacent tooth grooves in the implementation case; Figure 2 The positional relationship between the grinding wheel and the gear in the described misaligned herringbone gear grinding process; Figure 3 To correct the misalignment of the herringbone teeth and the grinding wheel through modeling and simulation. Detailed Implementation The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] A method for designing process parameters for grinding misaligned herringbone gears in aerospace applications, wherein the misaligned herringbone gear includes a left helical gear, a central empty groove, and a right helical gear; the left helical gear and the right helical gear have the same helix angle β and normal module mn, and are misaligned with each other, denoted by the misalignment angle θ.

[0027] Offset grinding: The left helical gear and the right helical gear are offset opposing gears. When grinding the tooth groove of one of them with a grinding wheel, after the grinding wheel moves along the tooth groove being machined to the middle empty groove, it can continue to move along the feed direction to the tooth groove of the offset opposing gear.

[0028] Misalignment angle: The misalignment angle formed between the left and right helical gears allows the grinding wheel to continue moving in the feed direction after it moves to the middle empty groove position, thereby shortening the empty groove distance and reducing the weight of the gears.

[0029] The method includes the following steps: Calculate the decision parameters K, Ka, and Kb according to the decision formula.

[0030]

[0031] L is the width of the empty tool groove. This is the misalignment angle coefficient, whose value is related to the misalignment angle and is 1 / 2.

[0032] According to the judgment formula Calculate the decision parameters Ka and Kb.

[0033] This refers to the amount of backlash correction applied to the gear being machined.

[0034] , The pitch circle pitch of the gear being machined.

[0035] Determine whether the value of parameter K is within the first value range (Ka, Kb). If it is, then it is determined that it is capable of borrowing position grinding and the grinding wheel can obtain the maximum diameter Dmax.

[0036] The maximum diameter Dmax of the grinding wheel is calculated using the relevant formula.

[0037] The left and right helical gears are asymmetrically arranged. Compared with the determination parameter K of symmetrical herringbone gears, the K formula of this invention is more reasonable, which can reduce the empty groove distance L and gear weight, and is suitable for the determination and optimization of symmetrical herringbone gear parameters.

[0038] The angular difference between the left and right helical gears is within ±45° / Z, where Z is the number of teeth of the left or right helical gear.

[0039] When the helix angle β is less than 15°, in step 2, only it is determined whether K is in the range of (0, 0.25). If it is, misaligned grinding is possible; otherwise, it is not.

[0040] When the helix angle β is in the range of [15°, 35°], step 2 only determines whether K is in the range of (0.75, 1.25). If it is, misaligned grinding is possible; otherwise, it is not.

[0041] The number of teeth on a left or right helical gear ranges from 31 to 213.

[0042] Before starting step 1, first determine whether the helix angle β is greater than 35°. If it is, it is directly determined that it is non-misaligned grinding; otherwise, continue to execute step 1.

[0043] If it is determined in step 2 that grinding is not possible by borrowing, continue to determine whether K is in (0.25, 0.75) (identified as interference between opposite teeth) or (1.25, 1.75) (identified as interference between adjacent opposite teeth).

[0044] It provides a formula for calculating the maximum diameter of the grinding wheel with specific parameters, including intermediate substitution amounts U, V, ED, etc., as well as parameters such as tooth height h and tooth width w.

[0045] Example

[0046] Where Φu is the addendum circle diameter of the gear being machined, Φd is the dedendum circle diameter of the gear being machined, h = 0.5(Φu - Φd), and θ is the misalignment angle; To determine the misalignment of the herringbone gears by considering the parameters of the adjacent tooth slots, we take the open groove width L, helix angle β, and normal module mn of gears A1 and A2. Using π (3.1416), pitch circle pitch Sp = πm / cosβ, and backlash trimming J = 0.05, we substitute these parameters into the above formula to obtain gear A1 or A2:

[0047] If the K value of herringbone gear A1 or A2 belongs to (Ka, Kb), then it is determined that herringbone gear A1 or A2 can be ground by borrowing, and the maximum diameter Dmax of the grinding wheel for borrowing grinding can be obtained; Calculate according to the formula:

[0048] Intermediate substitution quantity is , ;

[0049] in

[0050] Where L is the width of the herringbone gear cutter groove, Ru = 0.5Φu is the addendum circle radius, β is the helix angle, Z is the number of teeth, and h = 0.5(Φu—Φd) is the tooth height; the parameters are substituted into the formula for calculation:

[0051] Intermediate substitution quantity is , :

[0052] in

[0053] The intermediate substitution quantities ∠fcf′, df′, ∠ne'e are as follows:

[0054] Where Su is the tooth thickness of the tooth tip arc, w is the tooth width, and Rm is the pitch circle radius.

[0055] Calculations show that the maximum diameter DMax of the herringbone gear A1 or A2 borrowing grinding wheel is 68.2281 mm for A1 and 75.6675 mm for A2.

[0056] The above description is merely a specific embodiment of the present invention, providing a detailed description of the invention. Parts not covered herein are conventional techniques. However, the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for designing grinding process parameters for aerospace misaligned herringbone gears, wherein the misaligned herringbone gear includes a left helical gear, a central empty groove, and a right helical gear; the left and right helical gears have the same helix angle β and normal module mn, and the left and right helical gears are misaligned, denoted by a misalignment angle θ; characterized in that: The steps are as follows: Step 1: Calculate the judgment parameter K according to the judgment formula; Step 2: Determine whether the value of parameter K is within the first value range (Ka, Kb). If it is, it is determined that it is a grinding process that can be borrowed and the grinding wheel can obtain the maximum diameter Dmax; otherwise, it is determined that it is a grinding process that cannot be borrowed. Step 3: Calculate the maximum diameter Dmax of the grinding wheel.

2. The method according to claim 1, characterized in that: The determination formula is as follows: L is the width of the herringbone gear cutter groove. This is the misalignment angle coefficient.

3. The method according to claim 2, characterized in that: The method also includes step zero: determining whether the helix angle β is greater than 35°. If so, it is directly determined that it is non-misaligned grinding and the method ends; otherwise, step one is executed.

4. The method according to claim 3, characterized in that: In step two, if the helix angle β is less than 15°, Ka = 0 and Kb = 0.

25.

5. The method according to claim 4, characterized in that: In step two, when the helix angle β is in the range of [15°, 35°], Ka = 0.75 and Kb = 1.

25.

6. The method according to claim 5, characterized in that: In step two, if it is non-borrowing grinding, then determine whether K is in the range of (0.25, 0.75). If so, then determine whether there is interference between the opposite teeth.

7. The method according to claim 6, characterized in that: In step two, if it is non-borrowing grinding, then determine whether K is in the range of (1.25, 1.75). If so, then determine whether the adjacent teeth on the opposite side are interfering.

8. The method according to claim 7, characterized in that: The calculation process for Dmax is as follows: Intermediate substitution quantity is , ; Φu is the addendum circle diameter of the gear being machined, Φd is the root circle diameter of the gear being machined, h=0.5 (Φu—Φd); Where L is the width of the herringbone gear cutter groove, Ru=0.5Φu is the addendum circle radius, β is the helix angle, Z is the number of teeth, and h =0.5(Φu—Φd) is the tooth height; Substitute the parameters into the formula to calculate: Intermediate substitution quantity is , : in The intermediate substitution quantities ∠fcf′, df′, ∠ne'e are as follows: Where Su is the tooth thickness of the tooth tip arc, w is the tooth width, and Rm is the pitch circle radius.

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