A combined double helical internal gear ring machining method

Abstract

The present application relates to the technical field of inner gear ring processing, and discloses a combined herringbone inner gear ring processing method, which comprises the following steps: drilling set-up holes in two inner gear rings, assembling and connecting the two inner gear rings; drilling positioning pin holes on the assembled two inner gear rings; disassembling the two inner gear rings, processing a first positioning groove by using a five-axis machining center, and the axis of the first positioning groove is located in the vertical plane of the connecting line between the center of the inner gear ring and the center of the positioning pin hole; and processing the inner gear ring by using the first positioning groove as the starting tooth groove. Since the positioning is performed first and then the processing, the combined herringbone inner gear ring processing method does not need to ensure the centering accuracy of the herringbone by using a three-coordinate detection method or other detection methods during the processing, compared with the existing processing technology, two three-coordinate detection processes and one gear grinding process are reduced, the turnover time is significantly reduced, and the processing time and processing detection cost are reduced.

Description

Technical Field

[0001] This invention relates to the field of internal gear ring machining technology, and more specifically, to a method for machining a combined herringbone internal gear ring. Background Technology

[0002] Typically, a one-piece herringbone internal gear ring requires a sufficiently wide relief groove in the middle of the left and right helical teeth to avoid tool interference with the tooth surface during gear shaping or grinding. However, due to the structural limitations of the gearbox, the relief groove of the herringbone internal gear ring is small, making it impossible to use a one-piece machining method. The tooth surfaces of the left and right helical teeth can only be machined separately and then assembled into a herringbone gear. Therefore, the alignment accuracy of the herringbone gear is very high.

[0003] The existing machining process for combined herringbone internal gear rings involves: rough machining the tooth surfaces of the left and right helical teeth; assembling the two internal gear rings and checking the alignment accuracy of the herringbone teeth using a coordinate measuring machine (CMM); drilling assembly holes to correct the alignment accuracy of the herringbone teeth and then fastening the two internal gear rings together; checking the corrected alignment error of the herringbone teeth using a CMM to obtain the correction directions for the left and right helical teeth; and finally, disassembling the two internal gear rings and performing fine grinding on each. This machining process is complex, has high machining and inspection costs, and is time-consuming.

[0004] In summary, how to simplify the machining process of the combined herringbone internal gear ring is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a combined herringbone internal gear ring machining method, which first positions the gear and then processes it, eliminating the need to ensure the centering accuracy of the herringbone teeth through coordinate measuring machine or other detection methods during machining, significantly reducing turnaround time, machining time and machining inspection costs.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for machining a combined herringbone internal gear ring includes:

[0008] Drill assembly holes in the two internal gear rings, assemble and connect the two internal gear rings;

[0009] Positioning pin holes are drilled on both of the assembled internal gear rings;

[0010] Disassemble the two internal gear rings and use a five-axis machining center to machine the first positioning groove. The axis of the first positioning groove is located in the vertical plane containing the line connecting the center of the internal gear ring and the center of the positioning pin hole.

[0011] Using the first positioning groove as the starting tooth groove, the internal gear ring is machined by tooth cutting.

[0012] Preferably, before machining the first positioning groove, the center of the internal gear ring is determined using the large end face of the internal gear ring as the positioning reference surface.

[0013] Preferably, after drilling the positioning pin holes and before disassembling the two internal gear rings, a positioning reference surface is machined on the outer circumferential surface of the two internal gear rings in the assembled state.

[0014] Preferably, before machining the first positioning groove, the center of the positioning pin hole is determined by the probe of the five-axis machining center using the three-point centering principle.

[0015] Preferred options also include:

[0016] Based on the axis of the first positioning groove, a plurality of second positioning grooves are machined using the five-axis machining center. The angle γ between the axis of the second positioning groove and the axis of the first positioning groove satisfies γ=nβ, where n is a positive integer and β is the angle of the central angle between two adjacent tooth grooves of the internal gear ring.

[0017] Preferably, the dimensions of the first positioning groove and the second positioning groove are the same, and the groove depth of the first positioning groove and the second positioning groove is 0.5-1mm, and the width allowance is 2mm.

[0018] Preferably, with the first positioning groove as the starting tooth groove, the gear cutting of the internal gear ring includes:

[0019] During tooth shaping, the tooth shaping cutter is aligned with the first positioning groove to rough machine the starting tooth groove;

[0020] Adjust the eccentricity angle of the worktable of the gear hobbing machine so that the starting tooth groove is aligned with the first positioning groove;

[0021] After alignment, perform full-circle gear shaping on the internal gear ring.

[0022] Preferably, adjusting the eccentricity angle of the gear hobbing machine's worktable includes:

[0023] Measure the distances a and b between the two ends of the starting tooth groove and the two ends of the first positioning groove, and calculate the eccentricity angle α of the worktable of the gear shaping machine, α=2(ab) / Da, where Da is the tip circle diameter of the internal gear ring.

[0024] The present invention provides a method for machining a combined herringbone internal gear ring. First, two internal gear rings are assembled, and positioning pin holes are drilled on the two internal gear rings. Then, the first positioning groove is machined with the center of the positioning pin hole as the reference. Finally, the internal gear ring is machined with the first positioning groove as the starting tooth groove and the teeth are inserted.

[0025] Therefore, the combined herringbone internal gear ring processing method provided by this invention is to first position and then process, without having to ensure the centering accuracy of the herringbone teeth through three-coordinate detection or other detection methods during processing. Compared with the existing processing technology, it reduces two three-coordinate detection processes and one gear grinding process, significantly reducing turnaround time and lowering processing time and processing and inspection costs. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 A schematic diagram of a specific embodiment of the combined herringbone teeth provided by the present invention;

[0028] Figure 2 This is an assembly diagram of the internal gear ring in its assembled state;

[0029] Figure 3 This is a schematic diagram of the structure of the first positioning groove;

[0030] Figure 4 This is a schematic diagram illustrating the principle of adjusting the eccentricity angle of the worktable on a gear hobbing machine.

[0031] Figures 1-4 middle:

[0032] 1-Internal gear ring; 2-Assembly hole; 3-Fastening bolt; 4-Locking pin hole; 5-Locking pin; 6-First positioning groove. Detailed Implementation

[0033] 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The core of this invention is to provide a combined herringbone internal gear ring machining method, which first positions the gear and then processes it. This eliminates the need to ensure the alignment accuracy of the herringbone teeth through coordinate measuring machine or other detection methods during machining, significantly reducing turnaround time and lowering machining time and machining inspection costs.

[0035] The present invention provides a method for machining a combined herringbone internal gear ring, comprising:

[0036] Step S1: Drill assembly holes 2 in the two internal gear rings 1, assemble and connect the two internal gear rings 1;

[0037] Step S2: Drill positioning pin holes 4 on both assembled internal gear rings 1;

[0038] Step S3: Disassemble the two internal gear rings 1 and use a five-axis machining center to machine the first positioning groove 6. The axis of the first positioning groove 6 is located in the vertical plane of the line connecting the center of the internal gear ring 1 and the center of the positioning pin hole 4.

[0039] Step S4: Using the first positioning groove 6 as the starting tooth groove, the internal gear ring 1 is machined by tooth cutting.

[0040] It should be noted that in step S1, the assembly hole 2 is set perpendicular to the end face of the internal gear ring 1, and the distance from the center of the assembly hole 2 of the two internal gear rings 1 to the center of the internal gear ring 1 is the same, so as to ensure that the axes of the two internal gear rings 1 are collinear after assembly and connection.

[0041] Fasteners used to connect two internal gear rings 1 to assemble the two internal gear rings 1 are usually set as fastening bolts 3, which are easy to disassemble and have strong connection stability.

[0042] The dimensions of the assembly hole 2 are determined based on the inner and outer diameters of the two internal gear rings 1 and the design connection strength of the two internal gear rings 1 in actual production, so as to ensure the connection strength of the two internal gear rings 1 in the assembly state and avoid relative displacement of the two internal gear rings 1 during the subsequent drilling of the positioning pin hole 4.

[0043] It is necessary to explain step S2 that the positioning pin hole 4 is drilled on the two internal gear rings 1 in the assembled state to ensure that the position of the positioning pin hole 4 on the two internal gear rings 1 is the same, that is, the distance from the positioning pin hole 4 on the two internal gear rings 1 to the center is the same.

[0044] To ensure that the distance from the locating pin hole 4 on both internal gear rings 1 to the center is the same, the tool axis of the cutting tool should be adjusted to be perpendicular to the end face of the internal gear ring 1 before drilling, so that the axis of the locating pin hole 4 is parallel to the axis of the internal gear ring 1.

[0045] The specific dimensions of the locating pin hole 4 and the locating pin 5 are determined based on the inner and outer diameters of the internal gear ring 1 in actual production and the position measurement accuracy of the probe of the five-axis machining center, and will not be elaborated here.

[0046] It is necessary to explain step S3. After disassembling the two internal gear rings 1, the axis position of the first positioning groove 6 is determined by connecting the center of the positioning pin hole 4 and the center of the internal gear ring 1. The axis of the first positioning groove 6 is the intersection of the vertical plane containing the above-mentioned center connection and the inner circumferential surface of the internal gear ring 1.

[0047] To determine the axial position of the first positioning groove 6, the center of the internal gear ring 1 and the center of the positioning pin hole 4 can be determined by the three-point centering principle. To ensure that the three points selected for centering are coplanar, three points on the end face are usually selected for centering, such as the upper end face of the outer circumference of the internal gear ring 1 and the upper end face of the positioning pin hole 4.

[0048] The axis of the internal gear ring 1 and the axis of the locating pin hole 4 can also be determined by the six-point fixed axis principle. In this case, six points on the circumferential surface that are not located on the same plane need to be selected.

[0049] It should be noted that, considering that the inner circumferential surface of the internal gear ring 1 still needs to be machined for tooth grooves, it is usually not selected as the positioning reference surface. Instead, the large end face of the internal gear ring 1 is used as the positioning reference surface to determine the center of the internal gear ring 1.

[0050] To ensure the dimensional accuracy of the aforementioned positioning reference surface, preferably, after drilling the positioning pin hole 4 and before disassembling the two internal gear rings 1, the positioning reference surface is machined on the outer circumferential surface of the two internal gear rings 1 in the assembled state.

[0051] The positions of each point on the internal gear ring 1 and the locating pin hole 4 can be determined by the probe of the five-axis machining center. The probe can measure the coordinate position of each point, and then determine the coordinate position of the center or axis through the calculation center of the five-axis machining center. For example, the probe of the five-axis machining center can determine the center of the locating pin hole 4 through the three-point centering principle.

[0052] Of course, when the dimensional accuracy of the positioning reference surface is high enough, the center position of the internal gear ring 1 can also be determined by aligning the positioning reference surface with a dial indicator.

[0053] It should be noted that in steps S3 and S4, the first positioning groove 6 is used to position the machining area for subsequent gear shaping. Therefore, the dimensions of the first positioning groove 6 must be smaller than the design dimensions of the tooth grooves on the internal gear ring 1. To facilitate the machining of the first positioning groove 6, it is usually set as follows: Figure 3 The rectangular groove shown.

[0054] In this embodiment, two internal gear rings 1 are first assembled, and positioning pin holes 4 are drilled on the two internal gear rings 1. Then, the first positioning groove 6 is machined with the center of the positioning pin hole 4 as the reference. Finally, the internal gear ring 1 is machined with the first positioning groove 6 as the starting tooth groove and the teeth are inserted.

[0055] Therefore, the above-mentioned combined herringbone internal gear ring machining method is to first position and then process, without having to ensure the centering accuracy of the herringbone teeth through three-coordinate detection or other detection methods during processing. Compared with the existing processing technology, it reduces two three-coordinate detection processes and one gear grinding process, significantly reducing turnaround time and lowering processing time and processing and inspection costs.

[0056] Based on the above embodiments, in order to reduce the positional error of the gear shaping process, several second positioning grooves can be machined using a five-axis machining center according to the axis of the first positioning groove 6. The angle γ between the axis of the second positioning groove and the axis of the first positioning groove 6 satisfies γ=nβ, where n is a positive integer and β is the angle of the central angle between two adjacent tooth grooves of the internal gear ring 1.

[0057] It should be noted that the second positioning groove, which is usually furthest from the first positioning groove 6, is set with a central angle of less than or equal to 180° with the first positioning groove 6. In other words, the first positioning groove 6 and the second positioning groove only need to be set within half an angle of the internal gear ring 1.

[0058] To reduce the positional error of the tooth groove during slot machining, multiple first positioning grooves 6 and second positioning grooves are evenly distributed along the circumference of the internal gear ring 1. At this time, the angle between the axis of the second positioning groove and the axis of the first positioning groove 6 is γ=nβ, where n can form an arithmetic sequence, for example n=4,8,12,...,4m (m is the number of second positioning grooves, and m is a positive integer ≥4).

[0059] Typically, there are 4-5 tooth grooves between the first positioning groove 6 and the adjacent second positioning groove, and there are also 4-5 tooth grooves between two adjacent second positioning grooves. This can effectively ensure the positional accuracy of each tooth groove on the internal gear ring 1, and also avoid the total number of the first positioning groove 6 and the second positioning groove being too large, which would cause the machining time of the positioning groove to be too long.

[0060] In this embodiment, the setting of the second positioning groove is beneficial to reduce the positional error accumulated during slot processing, thereby improving the shape and position accuracy of the tooth groove that is far from the first positioning groove 6.

[0061] To facilitate the machining of the first positioning groove 6 and the second positioning groove, the dimensions of the first positioning groove 6 and the second positioning groove are usually set to be the same. Therefore, after the five-axis machining center completes the machining of the first positioning groove 6, it does not need to adjust the machining program, but only needs to adjust the position of the machining starting point, which helps to shorten the time required for the machining of the positioning groove.

[0062] Typically, a five-axis machining center can complete the machining of the positioning groove of one side of the internal gear ring 1 in only 40 minutes, which is a significant reduction in time compared to the existing machining process that uses a three-coordinate measuring machine to detect and correct the centering accuracy of the herringbone teeth.

[0063] The specific dimensions of the first positioning groove 6 and the second positioning groove are determined according to the design dimensions of the tooth groove of the internal gear ring 1 in actual production. Usually, the groove depth of the first positioning groove 6 and the second positioning groove is set to 0.5-1mm, the width allowance is 2mm, and the axial length is set to about 1 / 4 of the tooth width.

[0064] The groove depth is the radial dimension of the first positioning groove 6 / second positioning groove, and the width allowance is the sum of the distances from the two ends of the first positioning groove 6 / second positioning groove to the two ends of the tooth groove. Typically, the first positioning groove 6 / second positioning groove is symmetrically arranged about its axis so that the axis of the first positioning groove 6 / second positioning groove and the axis of the tooth groove are collinear.

[0065] Based on the above embodiments, the gear hobbing process is further defined, and step S4 may include:

[0066] Step S41: During gear shaping, align the gear shaping cutter with the first positioning groove 6 and rough machine the starting tooth groove;

[0067] Step S42: Adjust the eccentric angle of the worktable of the gear hobbing machine so that the starting tooth groove is aligned with the first positioning groove 6;

[0068] Step S43: After alignment, perform full-circle gear shaping of the internal gear ring 1.

[0069] It should be noted that in step S41, the initial tooth groove formed by rough machining has a cross-sectional dimension smaller than the designed cross-sectional dimension of the tooth groove, such as... Figure 4 As shown, its specific dimensions need to be determined based on factors such as the design cross-sectional dimensions of the tooth groove in actual production, so as to reserve sufficient adjustment margin and facilitate the centering and correction of the shape and position of the starting tooth groove when the worktable of the gear shaping machine is eccentric.

[0070] It should be noted that before adjusting the eccentricity angle of the gear hobbing machine's worktable, the eccentricity angle of the worktable of the gear hobbing machine needs to be measured. The aforementioned eccentricity angle of the worktable can be directly measured and determined by an inclinometer or similar device.

[0071] Preferably, in order to avoid large measurement errors when directly measuring the eccentricity angle of the worktable, the distances a and b between the two ends of the starting tooth groove and the two ends of the first positioning groove 6 can be measured, and the eccentricity angle α of the worktable of the gear shaping machine can be calculated, α=2(ab) / Da, where Da is the tooth tip circle diameter of the internal gear ring 1.

[0072] Compared to directly measuring the eccentricity angle, length measurement is simpler to operate and has higher accuracy and precision.

[0073] It should be noted that the first and second positioning slots mentioned in this application are only used to distinguish the different positions and do not limit the order.

[0074] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0075] The above provides a detailed description of the combined herringbone internal gear ring machining method provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A method for machining a combined herringbone internal gear ring, characterized in that, include: Drill assembly holes (2) in the two internal gear rings (1), and assemble and connect the two internal gear rings (1); Positioning pin holes (4) are drilled on both of the assembled internal gear rings (1). Disassemble the two internal gear rings (1) and use a five-axis machining center to machine the first positioning groove (6). The axis of the first positioning groove (6) is located in the vertical plane of the line connecting the center of the internal gear ring (1) and the center of the positioning pin hole (4). Using the first positioning groove (6) as the starting tooth groove, the internal gear ring (1) is machined by tooth cutting.

2. The method for machining a combined herringbone internal gear ring according to claim 1, characterized in that, Before machining the first positioning groove (6), the center of the internal gear ring (1) is determined by taking the large end face of the internal gear ring (1) as the positioning reference surface.

3. The method for machining a combined herringbone internal gear ring according to claim 2, characterized in that, After drilling the positioning pin hole (4) and before disassembling the two internal gear rings (1), a positioning reference surface is machined on the outer circumferential surface of the two internal gear rings (1) in the assembled state.

4. The method for machining a combined herringbone internal gear ring according to claim 1, characterized in that, Before machining the first positioning groove (6), the center of the positioning pin hole (4) is determined by the probe of the five-axis machining center through the three-point centering principle.

5. The method for machining a combined herringbone internal gear ring according to any one of claims 1-4, characterized in that, Also includes: Based on the axis of the first positioning groove (6), several second positioning grooves are machined using the five-axis machining center. The angle γ between the axis of the second positioning groove and the axis of the first positioning groove (6) satisfies γ=nβ, where n is a positive integer and β is the angle between the central angles of two adjacent tooth grooves of the internal gear ring (1).

6. The method for machining a combined herringbone internal gear ring according to claim 5, characterized in that, The dimensions of the first positioning groove (6) and the second positioning groove are the same. The groove depth of the first positioning groove (6) and the second positioning groove is 0.5-1mm, and the width margin is 2mm.

7. The method for machining a combined herringbone internal gear ring according to any one of claims 1-4, characterized in that, Using the first positioning groove (6) as the starting tooth groove, the gear cutting of the internal gear ring (1) includes: During tooth cutting, the tooth cutting cutter is aligned with the first positioning groove (6) to rough machine the starting tooth groove; Adjust the eccentricity angle of the worktable of the gear hobbing machine so that the starting tooth groove is aligned with the first positioning groove (6). After alignment, perform full-circle gear cutting of the internal gear ring (1).

8. The method for machining a combined herringbone internal gear ring according to claim 7, characterized in that, The adjustment of the eccentricity angle of the worktable of the gear hobbing machine includes: Measure the distances a and b between the two ends of the starting tooth groove and the two ends of the first positioning groove (6), and calculate the eccentricity angle α of the worktable of the gear shaping machine tool, α=2(ab) / Da, where Da is the tooth tip circle diameter of the internal gear ring (1).

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