A honing wheel and a design method thereof, and a double helical gear and a processing method thereof

Abstract

The application discloses a honing wheel and a design method thereof, a double helical gear and a machining method thereof, and belongs to the field of part machining. The method firstly determines initial parameters of the honing wheel through parameters of a double helical gear to be machined, establishes a checking relationship according to the parameters of the double helical gear and the initial parameters of the honing wheel based on the requirement of the tooth surface accuracy of the double helical gear, checks the initial parameters by using the checking relationship, and outputs the initial parameters when the requirement is met, and adjusts the initial parameters until the requirement is met when the requirement is not met. The method can quickly calculate whether the parameters of the double helical gear honing wheel meet the processing requirement of the relief groove, and facilitates designers to optimize and adjust the parameters of the honing wheel. The method can solve the technical problems that the tooth surface accuracy of the double helical gear is difficult to guarantee and the processing efficiency is low.

Description

Technical Field

[0001] This invention belongs to the field of parts processing, specifically relating to a honing wheel and its design method, and a herringbone gear and its processing method. Background Technology

[0002] With the rapid development of electric vehicles, the speed range of electric reducers is expanding, with the highest speed exceeding 25,000 rpm. At high speeds, electric drive systems face challenges related to noise, efficiency, and reliability, thus requiring increasingly higher precision levels for high-speed reducer gears. Currently, most high-speed reducers used in electric vehicles employ parallel shaft helical gear transmissions. Helical gear transmissions offer advantages such as high overlap ratio, high precision, smooth transmission, mature manufacturing methods, and low cost. However, with the extreme demands on power density and noise performance of electric drive systems, the performance of helical gear transmissions has reached a bottleneck and cannot meet the requirements of high-speed reducers. Compared to helical gear transmissions, herringbone gears consist of two symmetrical tooth surfaces with opposite helix directions, featuring a large helix angle and high overlap ratio. Furthermore, herringbone gear transmissions offer high load-bearing capacity, minimal or no axial force during meshing, and excellent noise performance, meeting the high power density and low noise requirements of future electric vehicles.

[0003] Compared to mature machining methods for helical gears, such as hobbing followed by grinding, most existing herringbone gears are machined using milling. Herringbone gears machined by hobbing and grinding require a large relief groove width. Due to the limitations of the tooth structure, high-precision herringbone gears with narrow relief grooves cannot be machined using hobbing and grinding methods. If form milling is used, it is difficult to guarantee machining efficiency and tooth surface accuracy, and the machining cost is high. Therefore, the machining of high-precision herringbone gears with narrow relief grooves is difficult, which restricts the use of herringbone gear high-speed reducers in electric vehicles. Summary of the Invention

[0004] To overcome the above-mentioned technical defects, the present invention provides a honing wheel and its design method, a herringbone gear and its processing method, which can solve the technical problems of difficult to guarantee the tooth surface accuracy of herringbone gears and low processing efficiency.

[0005] To achieve the above objectives, the present invention employs the following technical content:

[0006] A method for designing a honing wheel includes:

[0007] Determine the initial parameters of the honing wheel based on the parameters of the herringbone gear;

[0008] Establish a verification relationship regarding the width of the herringbone gear relief groove based on the parameters of the herringbone gear and the initial parameters of the honing wheel;

[0009] The initial parameters are input into the verification relationship for verification. If the requirements are met, the initial parameters are output as the final design parameters. If the requirements are not met, the initial parameters are adjusted and the verification relationship is re-entered until the verification requirements are met. The parameters that meet the requirements are then output as the final design parameters.

[0010] Furthermore, the specific formula for the verification relationship is as follows:

[0011]

[0012]

[0013]

[0014] in, This indicates the center distance between the herringbone gear and the honing wheel; Indicates the tip circle diameter of the herringbone gear; The pitch circle diameter of the honing wheel is represented by x; the point where the pitch circle of the herringbone gear coincides with the projection of the pitch circle of the honing wheel is M, and x and y represent the horizontal and vertical coordinates of the coincident point M, respectively. This represents the specific calculated value of x; Indicates the angle between the mounting shaft of the herringbone gear and the honing wheel; This indicates the width of the relief groove on the herringbone gear.

[0015] Furthermore, if the requirements are not met, the number of teeth, helix angle, and installation shaft intersection angle in the initial parameters are adjusted until the verification requirements are met.

[0016] A honing wheel is manufactured based on the above-described honing wheel design method.

[0017] Further, it includes: a wheel-shaped structure, the inner wall of which is provided with a first wheel tooth and a second wheel tooth; an intermediate relief groove is provided between the first wheel tooth and the second wheel tooth.

[0018] A method for machining a herringbone gear, comprising:

[0019] S1: The gear blank is forged to obtain a herringbone gear blank;

[0020] S2: Roughly machine the herringbone gear blank to obtain a rough-machined herringbone gear;

[0021] S3: The rough-machined herringbone gear is subjected to heat treatment and tooth surface strengthening treatment in sequence to obtain a semi-finished herringbone gear;

[0022] S4: The herringbone gear is precision machined using the honing wheel to obtain the herringbone gear.

[0023] Furthermore, in S2, rough machining is performed using gear shaping or gear turning.

[0024] Furthermore, in S3, the rough-machined herringbone gear is subjected to heat treatment in sequence so that the tooth surface deformation is ≤0.02mm; the rough-machined herringbone gear is subjected to tooth surface strengthening treatment, wherein the residual stress on the tooth surface and tooth root is not less than 800Mpa.

[0025] Furthermore, in S4, a honing wheel is used to hone the herringbone gear so that the allowance on one side is ≤0.04 mm.

[0026] A herringbone gear is manufactured using the aforementioned herringbone gear processing method.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] This invention provides a design method for honing wheels. The method first determines the initial parameters of the honing wheel based on the parameters of the herringbone gear to be machined. Based on the accuracy requirements of the herringbone gear tooth surface, a verification relationship is established according to the herringbone gear parameters and the initial parameters of the honing wheel. The initial parameters are then verified using this verification relationship; if the requirements are met, the initial parameters are output; otherwise, the initial parameters are adjusted until the requirements are met. This method can quickly calculate whether the parameters of the herringbone gear honing wheel meet the requirements for the relief groove machining, facilitating designers to optimize and adjust the honing wheel parameters.

[0029] This invention provides a honing wheel, manufactured using the aforementioned design method. This honing wheel enables precision machining of herringbone gears, meeting the high-precision requirements of the herringbone gear tooth surfaces. The honing wheel allows for one-time clamping on a honing machine. By adjusting the included angle of the honing wheel's mounting shaft using a CNC system, the left and right helical gear teeth of the herringbone gear workpiece can be machined, improving the symmetry of the left and right helical gear tooth surfaces. Furthermore, since the honing wheel parameters have been verified and optimized, the machining efficiency of herringbone gear honing is improved.

[0030] The present invention also provides a method for machining herringbone gears. Based on the above-mentioned honing wheel, this method adopts a composite machining process of rough machining and honing for herringbone gears, which can realize the machining of high-precision narrow relief groove herringbone gears for high-speed reducers of electric vehicles, and the width of the relief groove in the middle of the herringbone teeth can be controlled within 5mm. This method meets the high-precision machining requirements of herringbone gears.

[0031] Preferably, when the rough-machined herringbone gear is subjected to heat treatment in sequence, the tooth surface deformation is controlled to be ≤0.02 mm, and when the herringbone gear is honed, the allowance on one side is controlled to be ≤0.04 mm. In this way, the symmetry requirement of the teeth on the left and right helical surfaces of the herringbone gear about the center plane can be guaranteed; the symmetry can be controlled to be ≤0.03 mm, thereby ensuring the high precision requirement.

[0032] The present invention also provides a herringbone gear, which is manufactured by the above-mentioned processing method. This herringbone gear can be used in electric vehicles. Based on its structural features, namely high-precision tooth surface and narrow relief groove, it can effectively improve the power density and reliability of electric drive system, while reducing system noise. Attached Figure Description

[0033] Figure 1 A schematic diagram of the herringbone gear provided in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the honing wheel provided in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the machining of the left side teeth of the herringbone gear provided in an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the machining of the right-side gear teeth of a herringbone gear provided in an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of honing wheel parameter verification provided in an embodiment of the present invention;

[0038] Figure 6 This is a 3D inspection diagram of the installation of the herringbone gear and honing wheel provided in an embodiment of the present invention.

[0039] Figure label:

[0040] Herringbone gear-1; Honing wheel-2;

[0041] Left gear tooth -1-1; Center face -1-2; Right gear tooth -1-3;

[0042] First gear -2-1; Intermediate relief groove -2-2; Second gear -2-3. Detailed Implementation

[0043] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0046] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0047] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0048] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0049] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0050] The present invention will now be described in further detail with reference to the accompanying drawings:

[0051] Example

[0052] As mentioned in the background section, most existing herringbone gears are machined using milling. Herringbone gears machined using hobbing and grinding require a large relief groove width. Due to the limitations of the tooth structure, high-precision narrow relief groove herringbone gears cannot be machined using hobbing and grinding methods. If form milling is used, the machining efficiency and tooth surface accuracy are difficult to guarantee, and the machining cost is high. Therefore, the machining of high-precision narrow relief groove herringbone gears is difficult, which restricts the use of herringbone gear high-speed reducers in electric vehicles.

[0053] To address the aforementioned technical problems, this embodiment provides a honing wheel and its design method, as well as a herringbone gear and its machining method; it overcomes the shortcomings of low machining efficiency, large requirements for relief groove width, and difficulty in guaranteeing tooth surface accuracy of herringbone gears, thereby meeting the transmission requirements of electric herringbone gear high-speed reducers.

[0054] The following is a detailed description of this embodiment with reference to the accompanying drawings:

[0055] This embodiment provides a honing wheel specifically designed for manufacturing high-precision herringbone gears with narrow relief grooves. The design method is as follows:

[0056] The initial parameters of the honing wheel are designed based on the known parameters of the herringbone gear to be machined, as shown in the table below:

[0057] Table 1 shows the parameters of herringbone gears and honing wheels.

[0058]

[0059] Installation parameters: center distance Angle with mounting shaft

[0060] like Figure 5 As shown, in the coordinate system S(Oxy), the origin O is the center of the honing wheel, the xy plane is perpendicular to the axis of the herringbone gear, O1 is the center of the herringbone gear, and OO1 is the center distance a between the herringbone gear and the honing wheel. In the xy plane, the point where the projection of the addendum circle of the herringbone gear coincides with that of the addendum circle of the honing wheel is M. The trajectory of the addendum circle of the honing wheel in the xy plane is elliptical. The dashed line in the figure is the trajectory of the addendum circle of the honing wheel on its end face.

[0061] At point M(x,y), the requirements for the addendum circle of the herringbone gear are satisfied:

[0062] Formula 1

[0063] At point M(x,y), the honing wheel tooth tip circle requirement is satisfied:

[0064] Formula 2

[0065] Solving by combining formulas 1 and 2, we can obtain the following: ; This represents the specific calculated value of x;

[0066] In the above formula, x and y are both positive values; in order to machine herringbone gears, the following must be satisfied:

[0067] Formula 3

[0068] in, This indicates the width of the herringbone gear relief groove; in practice, to prevent collision with the honing wheel, it needs to be smaller than the relief groove width.

[0069] Taking the parameters of a certain herringbone gear as an example, the process of verifying the honing wheel parameters is as follows:

[0070] The specific parameters are shown in Table 2:

[0071] Table 2 shows the parameters of the herringbone gear and the actual parameters of the honing wheel.

[0072]

[0073] The parameters in Table 2 have the same meaning as those in Table 1, and will not be repeated here.

[0074] Substituting the parameters of the herringbone gear and the honing wheel into formulas 1 and 2, we can obtain: 13.4716;

[0075] When selecting a herringbone tooth relief groove, the maximum value of machining collision should be considered. ;

[0076] .

[0077] The honing wheel parameters are checked according to the above formula. If the requirements are met, the corresponding honing wheel parameters are output. If the requirements are not met, the above parameters need to be adjusted, specifically the number of teeth, helix angle, and installation shaft angle of the honing wheel. At least one of these parameters needs to be adjusted until the requirements of Formula 3 are met. Then, the honing wheel parameters that meet the requirements are output. Thus, the design of the honing wheel is completed.

[0078] like Figure 2As shown, this embodiment also provides a honing wheel. The internal tooth surface of this honing wheel 2 is in the form of a herringbone gear. The helix angle parameters of the first gear tooth 2-1 and the second gear tooth 2-3 are opposites, while other parameters are the same. The first gear tooth 2-1 is used to machine the right gear tooth 1-3 of the herringbone gear 1, and the second gear tooth 2-3 is used to machine the left gear tooth 1-1 of the herringbone gear 1. There is a central relief groove 2-2 in the middle of the gear teeth. This relief groove is not affected by the workpiece being machined. During the manufacturing of the honing wheel, only the spatial dimensions for grooving and dressing the honing wheel need to be considered. During the grooving and dressing process of the honing wheel, the symmetry of the left and right gear teeth of the honing wheel needs to be ensured.

[0079] It should be noted that the internal teeth of the honing wheel 2 are divided into two helical teeth, namely the first tooth 2-1 and the second tooth 2-3, with a central relief groove 2-2 in the middle. The helix angle parameters of the left and right teeth are opposites of each other, while other parameters are the same. The helix angle and helix direction of the honing wheel 2 are determined based on the helix angle and helix direction of the herringbone gear 1 to be machined, as well as the shaft intersection angle. When machining the herringbone gear 1, the first tooth 2-1 of the honing wheel 2 is used to machine the right tooth 1-3 of the herringbone gear 1. Then, the swing angle of the honing wheel base of the machine tool is adjusted by the CNC system to adjust the angle between the honing wheel 2 and the shaft of the herringbone gear 1. Then, the second tooth -2-3 of the honing wheel 2 is used to machine the left tooth 1-1 of the herringbone gear 1. Of course, the machining sequence can also be to machine the left tooth 1-1 of the herringbone gear 1 first and then machine the right tooth 1-3 of the herringbone gear 1. Here, the left and right teeth of the honing wheel 2 are clamped in one operation to ensure the positional accuracy requirements.

[0080] Based on the aforementioned honing wheel 2, this embodiment also provides a herringbone gear and its machining method. The specific structure of the herringbone gear is as follows: Figure 1 As shown, it includes: left gear tooth 1-1, center surface 1-2 and right gear tooth 1-3.

[0081] The steps for making a herringbone gear are as follows:

[0082] Step 1: Select 8620RH steel to manufacture gear blanks. The gear blanks are formed by forging; thus, a herringbone gear blank is obtained.

[0083] Step 2: Roughly machine the herringbone gear blank on a gear shaper or gear turning machine, ensuring the tooth machining meets the national standard grade 7 precision; thus obtaining the rough-machined herringbone gear.

[0084] Step 3: Carburize and quench the rough-machined herringbone gear in a carburizing ring furnace, controlling the tooth surface deformation to ≤0.02mm; after heat treatment, strengthen the tooth surface of the herringbone gear to ensure that the residual stress on the tooth surface and tooth root is above 800Mpa, and obtain the semi-finished herringbone gear.

[0085] Step 4: Using the two pairs of honing wheels described above on a honing machine, perform finishing machining of the herringbone gear semi-finished product to obtain the herringbone gear. During this process, adjust the machine tool mounting center distance and the angle between the mounting shaft parameters, such as... Figure 3 and Figure 4 As shown, first use the first gear tooth 2-1 of the honing wheel to machine the right gear tooth 1-3 of the herringbone gear 1, as follows. Figure 6 As shown, the angle parameters between the honing wheel and the herringbone gear shaft are adjusted by the CNC system (the angle parameters of the shafts for machining the teeth on both sides are opposite numbers). Then, the second gear tooth 2-3 of the honing wheel is used to machine the left gear tooth 1-1 of the herringbone gear 1. The honing allowance is controlled to be ≤0.04mm on one side. In this way, the finish machining ensures that the symmetry of the teeth on the left and right helical surfaces of the herringbone gear about the center plane is ≤0.03mm.

[0086] This invention provides a honing wheel and its design method, a herringbone gear and its processing method. Compared with the prior art, this invention has the following beneficial technical effects:

[0087] 1. This invention employs a composite machining process for herringbone gears, involving rough machining by gear shaping or turning and fine machining by honing. This process enables the machining of high-precision herringbone gears with narrow relief grooves for high-speed reducers in electric vehicles, and the width of the relief groove in the middle of the herringbone gear can be controlled within the range of 5mm.

[0088] 2. The herringbone gear processed by this invention can be applied to electric vehicles to effectively improve the power density and reliability of the electric drive system, while reducing system noise.

[0089] 3. The honing wheel tool for herringbone gears provided by this invention can be clamped on a honing machine tool in one go. By adjusting the included angle of the honing wheel mounting shaft through the CNC system, the left and right helical gear teeth of the herringbone gear workpiece can be machined, thereby improving the symmetry of the left and right helical gear tooth surfaces.

[0090] 4. The herringbone gear honing wheel tool design parameter verification method provided by the present invention can quickly calculate whether the parameters of the herringbone gear honing wheel meet the requirements of the relief groove machining, which facilitates designers to optimize and adjust the honing wheel parameters.

[0091] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A method of designing a honing stone, characterized by, The application relates to a design method of a honing wheel for a double helical gear. The initial parameters of the honing wheel are determined according to the parameters of the double helical gear; A checking relation about the width of the relief groove of the double helical gear is established according to the parameters of the double helical gear and the initial parameters of the honing wheel; If the initial parameters meet the requirements, the initial parameters are output as the final design parameters; If the initial parameters do not meet the requirements, the initial parameters are adjusted and input into the checking relation again until the checking requirements are met, and the parameters meeting the requirements are output as the final design parameters; The specific formula of the checking relation is as follows: wherein, represents the center distance of the double helical gear and the honing wheel; represents the addendum circle diameter of the double helical gear; represents the addendum circle diameter of the honing wheel; the projection overlapping point of the addendum circle of the double helical gear and the addendum circle of the honing wheel is M, and x and y respectively represent the horizontal coordinate and the vertical coordinate of the overlapping point M; represents the specific calculation value of x; represents the installation shaft intersection angle of the double helical gear and the honing wheel; represents the tool withdrawal groove width of the double helical gear.

2. The design method of the honing stone according to claim 1, wherein If the initial parameters do not meet the requirements, the number of teeth, the helix angle and the intersection angle of the mounting shaft in the initial parameters are adjusted until the checking requirements are met. The honing wheel is prepared by the design method of claim 1 or 2.

3. A honing stone characterized by comprising: The application relates to a honing wheel for a double helical gear.

4. A honing stone according to claim 3, wherein The application relates to a honing wheel for a double helical gear. S1: a gear blank is forged to obtain a double helical gear blank; 5. A method of machining a double helical gear, characterized by, S2: the double helical gear blank is roughly machined to obtain a roughly machined double helical gear; S3: the roughly machined double helical gear is sequentially subjected to heat treatment and tooth surface strengthening treatment to obtain a double helical gear semi-finished product; S4: the double helical gear is finely machined by the honing wheel of claim 3 to obtain a double helical gear. In S2, the rough machining adopts gear cutting or tooth turning. In S3, the roughly machined double helical gear is sequentially subjected to heat treatment, so that the tooth surface deformation is less than or equal to 0.02 mm; and the tooth surface of the roughly machined double helical gear is subjected to tooth surface strengthening treatment, wherein the residual stress of the tooth surface and the tooth root is not less than 800Mpa.

6. A method of machining a double helical gear as set forth in claim 5, characterized in that, In S4, the double helical gear is honed by the honing wheel, so that the excess single side is less than or equal to 0.04 mm.

7. The method of machining a double helical gear as set forth in claim 5, wherein, ​ 8. The method of machining a double helical gear as set forth in claim 5, wherein, ​

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