A double helical gear shaving cutter

Abstract

The application discloses a herringbone gear hobbing cutter, which comprises a hobbing cutter bar and hobs, the hobs are installed on the hobbing cutter bar, the hobs comprise first hobs and second hobs, the hobbing cutter bar is provided with an installation part, the first hobs and the second hobs are respectively installed on both ends of the installation part, the axial distance between the first hobs and the second hobs is L0, the stroke length of the herringbone gear is L, and L0 is greater than or equal to L, and the initial cutting teeth of the first hobs and the second hobs are located at the same angular position on the hobbing cutter bar. The application overcomes the single machining characteristic of the existing hobbing cutter, and ensures the high-precision manufacturing of the symmetry error of the intersection points of the helical lines of the two helical gears of the herringbone gear.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gear cutters, and particularly relates to a gear shaper cutter for high-precision herringbone gear and high-efficiency gear cutting of high-precision angular position multi-gear. BACKGROUND

[0002] The existing gear shaper cutter is used for gear cutting of herringbone gears, and the upper and lower helical gears of the herringbone gears are separately inserted (two processes) for gear cutting. The gear shaper cutters for the upper and lower helical gears are respectively and singly assembled on the cutter bar, and the upper and lower helical gears are respectively machined by changing the cutter and multiple times of alignment.

[0003] The symmetry error control of the intersection of the two helical gears of the herringbone gears is usually controlled by means of a process angular positioning reference (such as a line) designed on the gear blank, a clamp and an angular positioning device thereof, cutter alignment, compensation for gear cutting, and the like. Such gear shaper cutter and gear cutting technology have low machining efficiency, complicated gear cutting debugging, are not suitable for batch production, and the machining precision of the herringbone gears, especially the symmetry error of the intersection of the upper and lower helical spiral lines, is more than ±0.3 mm, which is difficult to meet the requirements of high-precision herringbone gear manufacturing and large-batch manufacturing. SUMMARY

[0004] The present application aims to overcome the deficiencies of the prior art and provide a gear shaper cutter for high-precision herringbone gear cutting.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] A gear shaper cutter for herringbone gear cutting includes a gear shaper cutter bar and a gear shaper cutter, the gear shaper cutter is installed on the gear shaper cutter bar, the gear shaper cutter includes a first gear shaper cutter and a second gear shaper cutter, the gear shaper cutter bar is provided with a mounting portion, the first gear shaper cutter and the second gear shaper cutter are respectively installed at both ends of the mounting portion, the axial distance between the first gear shaper cutter and the second gear shaper cutter is L0, the stroke length for gear cutting of the herringbone gear is L, and L0≥L is met.

[0007] Further improvement of the above technical solutions:

[0008] The mounting portion is provided with an axial positioning sleeve between the first gear shaper cutter and the second gear shaper cutter.

[0009] The gear shaper cutter bar further includes a cutter handle portion and an intermediate section, the cutter handle portion is installed on a main shaft of a gear shaper, the intermediate section is located between the cutter handle portion and the mounting portion, a fourth groove is provided on the outer circumferential surface of the intermediate section, and the bottom surface of the fourth groove serves as a cutter bar alignment reference surface.

[0010] The intermediate section is provided with a first slot on the end face close to the mounting part, the first slot and an end face slot on the end face of the first pinion cutter far from the cutting edge correspond to each other, and a first key is installed in the space between the first slot and the end face slot, the first key is used to prevent the rotation of the first pinion cutter and to position the initial cutting tooth of the first pinion cutter.

[0011] The outer circumferential surface of the mounting part is provided with a second slot, the inner wall of the positioning reference hole of the second pinion cutter is provided with a positioning slot, the center axis of the positioning slot is kept in the same angular position as the center line of any tooth on the second pinion cutter, the positioning slot and the second slot correspond to each other, and a second key is installed in the space between the positioning slot and the second slot, the second key is used to prevent the rotation of the second pinion cutter and to position the initial cutting tooth of the second pinion cutter.

[0012] The angular positions of the first key and the second key on the pinion cutter bar are the same.

[0013] The outer circumferential surface of the mounting part is provided with a third slot, the inner circumferential surface of the axial positioning sleeve is provided with an axial key slot, the third slot and the axial key slot correspond to each other, and a third key is installed in the space between the third slot and the axial key slot, the third key is used to prevent the rotation of the axial positioning sleeve.

[0014] The rotation directions of the first pinion cutter and the second pinion cutter are opposite.

[0015] The double helical gear includes an upper helical gear and a lower helical gear, the second pinion cutter is used to cut the upper helical gear of the double helical gear, and the rotation direction of the second pinion cutter is opposite to that of the upper helical gear, and the first pinion cutter is used to cut the lower helical gear of the double helical gear, and the rotation direction of the first pinion cutter is opposite to that of the lower helical gear.

[0016] The addendum circle diameter of the first pinion cutter is D1, the addendum circle diameter of the second pinion cutter is D2, and the tooth height of the double helical gear is h1, and D1-D2=(2.8-4)×h1 is satisfied.

[0017] Compared with the prior art, the advantages of the present application are that:

[0018] The present application overcomes the single machining characteristics of the existing pinion cutter, provides a combined pinion cutter for machining a double helical gear, installs two pinion cutters of different specifications on the cutter bar in the same direction at one time, and combines the pinion cutting method to create necessary conditions for machining the two helical gears of the double helical gear and simplifying the pinion cutting process at one time, reduces the installation errors of the cutter and the tooth blank, ensures the high-precision manufacturing of the symmetry error of the intersection points of the helical lines of the two helical gears of the double helical gear, improves the pinion cutting efficiency, and realizes the batch pinion cutting of the double helical gear. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 This is a schematic diagram of the herringbone gear of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of the gear shaping tool of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of the first gear shaping cutter of the present invention.

[0022] Figure 4 yes Figure 3 Top view of point A in the middle.

[0023] Figure 5 This is a schematic diagram of the structure of the second gear cutter of the present invention.

[0024] Figure 6 yes Figure 5 Top view at point B in the middle.

[0025] Figure 7 This is a schematic diagram of the structure of the gear shaping cutter bar of the present invention.

[0026] Figure 8 This is a bottom view of the gear shaping tool holder of the present invention.

[0027] Figure 9 This is a schematic diagram of the axial positioning sleeve of the present invention.

[0028] Figure 10 This is a bottom view of the axial positioning sleeve of the present invention.

[0029] Figure 11 This is a diagram showing the symmetry test results of the herringbone gear after processing with the gear shaping tool of this invention.

[0030] The labels in the diagram represent: 1. Gear shaper shank; 11. Tool holder; 12. Intermediate section; 121. Outer diameter of the large journal; 13. Mounting section; 131. Outer diameter of the first tool journal; 132. Outer diameter of the transition section; 133. Outer diameter of the second tool journal; 134. Outer diameter of the front end; 101. First groove; 102. Second groove; 103. Third groove; 104. Fourth groove; 141. First key; 142. Second key; 143. Third key; 2. First gear shaper; 21. End face groove; 3. Second gear shaper; 31. Positioning groove; 4. Herringbone gear; 41. Upper helical gear; 42. Lower helical gear; 5. Axial positioning sleeve; 51. Axial keyway. Detailed Implementation

[0031] The present invention will be further described in detail below. Unless otherwise specified, the instruments or materials used in the present invention are commercially available.

[0032] Example 1:

[0033] like Figure 1As shown, the herringbone gear 4 in this embodiment includes an upper helical gear 41 and a lower helical gear 42. The upper helical gear 41 is left-handed and the lower helical gear 42 is right-handed.

[0034] Table 1. Parameters of Herringbone Gear 4

[0035]

[0036] like Figures 1 to 10 As shown, the herringbone gear shaping tool of the present invention includes a shaping tool holder 1 and shaping cutters. The shaping cutters are mounted on the shaping tool holder 1 and include a first shaping cutter 2 and a second shaping cutter 3. The shaping tool holder 1 is provided with a mounting part 13. The first shaping cutter 2 and the second shaping cutter 3 are respectively mounted at both ends of the mounting part 13. The axial distance between the first shaping cutter 2 and the second shaping cutter 3 is L0, and the stroke length for shaping the herringbone gear 4 is L, satisfying L0≥L. By mounting two shaping cutters of different specifications in the same direction on the shaping tool holder 1 at one time, the necessary conditions are created for completing the shaping of the two helical gears of the herringbone gear blank in one installation and simplifying the shaping process. This reduces the installation error of the tool and the blank, ensures high-precision manufacturing of the symmetry error of the intersection point of the helical lines of the two helical gears of the herringbone gear 4, and improves the shaping efficiency, realizing the batch shaping of herringbone gears.

[0037] The mounting part 13 is fitted with an axial positioning sleeve 5 between the first gear cutter 2 and the second gear cutter 3.

[0038] The gear shaping tool holder 1 also includes a tool holder part 11 and an intermediate section 12. The tool holder part 11 is mounted on the spindle of the gear shaping machine (the tool holder part 11 and the spindle have the same dimensions). The intermediate section 12 is located between the tool holder part 11 and the mounting part 13. A fourth groove 104 is provided on the outer circumferential surface of the intermediate section 12. The bottom surface of the fourth groove 104 serves as the tool holder alignment reference surface.

[0039] The middle section 12 has a first groove 101 on the end face near the mounting part 13. The first gear cutter 2 has an end face groove 21 on the end face away from the cutting edge. The first groove 101 and the end face groove 21 correspond to each other and a first key 141 is installed in the space between the first groove 101 and the end face groove 21. The first key 141 is used to prevent the first gear cutter 2 from rotating and to position the initial cutting teeth of the first gear cutter 2.

[0040] A second groove 102 is provided on the outer peripheral surface of the mounting part 13. A positioning groove 31 is provided on the inner wall of the positioning reference hole inside the second gear cutter 3. The positioning groove 31 corresponds to the second groove 102 and a second key 142 is installed in the space between the positioning groove 31 and the second groove 102. The second key 142 is used to prevent the second gear cutter 3 from rotating and to position the initial cutting teeth of the second gear cutter 3.

[0041] The first key 141 and the second key 142 are at the same angular position on the gear shaping bar 1.

[0042] A third groove 103 is provided on the outer peripheral surface of the mounting part 13, and an axial keyway 51 is provided on the inner peripheral surface of the axial positioning sleeve 5. The third groove 103 and the axial keyway 51 correspond to each other, and a third key 143 is installed in the space between the third groove 103 and the axial keyway 51. The third key 143 is used to prevent the axial positioning sleeve 5 from rotating.

[0043] The first gear cutter 2 and the second gear cutter 3 have opposite directions of rotation and are used to cut helical gears with different directions of rotation of the herringbone gear 4.

[0044] The herringbone gear 4 includes an upper helical gear 41 and a lower helical gear 42. The second gear cutter 3 is used to cut the upper helical gear 41 of the herringbone gear 4 and the direction of rotation is opposite to that of the upper helical gear 41. The first gear cutter 2 is used to cut the lower helical gear 42 of the herringbone gear 4 and the direction of rotation is opposite to that of the lower helical gear 42.

[0045] The tip circle diameter of the first gear shaper 2 is D1, the tip circle diameter of the second gear shaper 3 is D2, and the tooth height of the herringbone gear 4 is h1, satisfying D1-D2=(2.8~4)×h1, ensuring that the first gear shaper 2 will not interfere with the upper helical gear 41 when shaping it. In this embodiment, both the first gear shaper 2 and the second gear shaper 3 are cup-shaped helical gear shapers (collectively referred to as gear shapers). The number of teeth of the first gear shaper 2 and the second gear shaper 3 can also differ by 5 to 8 teeth, ensuring that the difference between the tip circle diameter D1 of the first gear shaper 2 and the tip circle diameter D2 of the second gear shaper 3 is more than 2.8 times the tooth height of the herringbone gear 4.

[0046] In this embodiment, the first gear shaper 2 has 35 teeth, a left-hand helical direction, a tooth tip circle diameter D1 of φ145.99mm, and a positioning inner hole size designed to be a commonly used diameter of φ44.45mm; the second gear shaper 3 has 28 teeth, a right-hand helical direction, a tooth tip circle diameter D2 of φ118.145mm, and a positioning inner hole size designed to be a commonly used diameter of φ31.743mm. D1-D2=27.845mm, which is approximately 3.9 times the tooth height of the herringbone gear 4.

[0047] The second gear shaper 3 used for shaping the upper helical gear 41 has fewer teeth (correspondingly, the tip circle diameter of the tool is also smaller, also known as a small-diameter gear shaper), while the first gear shaper 2 used for shaping the lower helical gear 42 has more teeth (correspondingly, the tip circle diameter of the tool is also larger, also known as a large-diameter gear shaper). Furthermore, the diameter d1 of the positioning reference hole of the first gear shaper 2 used for shaping the lower helical gear 42 is larger than the diameter d2 of the positioning reference hole of the second gear shaper 3 used for shaping the upper helical gear 41.

[0048] The second gear shaping cutter 3 has a positioning groove 31 in its positioning reference hole, and the first gear shaping cutter 2 has an end face groove 21 on its end face away from the cutting end. The positioning groove 31 or the end face groove 21 is in the same radial direction (i.e., in the same angular position) as a tooth on the front end face of the gear shaping cutter that serves as the initial cutting tooth of the gear shaping cutter. That is, in this embodiment, the initial cutting teeth of the first gear shaping cutter 2 and the second gear shaping cutter 3 are located in the same angular position on the gear shaping cutter shank 1.

[0049] The gear shaper cutter 1 is designed with three sections: the shank section 11, the intermediate section 12, and the mounting section 13. The shank section 11 is determined by the spindle structure of the gear shaper. The length of the intermediate section 12 mainly depends on the total width H of the herringbone gear 4, and the outer diameter of the intermediate section 12 is consistent with the diameter of the gear shaper cutter support surface.

[0050] In this embodiment, the mounting part 13 includes three precision outer circles (with cylindrical outer walls) of different diameters and a front end outer circle 134 (with threaded outer walls) located in front of the precision outer circles. The three precision outer circles include two tool journal outer circles and a transition section outer circle 132 located between the two tool journal outer circles. The tool journal outer circles include a first tool journal outer circle 131 and a second tool journal outer circle 133, which are respectively used to mount the first gear cutter 2 and the second gear cutter 3. The diameter and length of the tool journal outer circles are respectively based on the positioning hole diameters of the corresponding two gear cutters and their... The length is determined such that the diameter of the outer circle 131 of the first tool journal is greater than the diameter of the outer circle 133 of the second tool journal; the outer circle 132 of the transition section is used to install the axial positioning sleeve 5 of the tool, and the diameter of the outer circle 132 of the transition section is between the diameters of the outer circle 131 of the first tool journal and the outer circle 133 of the second tool journal. The length mainly depends on the stroke length of the herringbone gear 4, ensuring that the axial distance L0 of the two gear shaping cutters is greater than or equal to the gear shaping stroke length L when the two gear shaping cutters are installed on the gear shaping cutter bar 1, so as to avoid interference between the other gear shaping cutter and the part or fixture when one gear shaping cutter is working.

[0051] In this embodiment, the outer diameter 133 of the second tool journal is provided with a second groove 102. The second groove 102 corresponds to the positioning groove 31 of the second gear hobbing cutter 3 and is used to install the second key 142 to restrict the rotation of the second gear hobbing cutter 3. The second key 142 is arranged in a direction parallel to the central axis of the tool holder.

[0052] In this embodiment, the outer circle 132 of the transition section is provided with a third groove 103, and the inner wall of the axial positioning sleeve 5 is provided with an axial keyway 51. The axial keyway 51 and the third groove 103 correspond to each other and are used to install the third key 143, which limits the rotation of the tool axial positioning sleeve 5 and facilitates the fixed installation of the gear shaping cutter. In this embodiment, the third groove 103 and the second groove 102 on the outer circle 133 of the second tool journal maintain an angle of 90° to enhance the rigidity of the tool holder.

[0053] The intermediate section 12 includes a large journal outer circle 121. A first groove 101 is provided on the end face near the mounting part 13. The first groove 101 corresponds to the end face groove 21 of the first gear shaping cutter 2 and is used to install the first key 141. A fourth groove 104 is provided along the circumferential direction of the large journal outer circle 121. The bottom surface of the fourth groove 104 serves as the tool holder alignment reference surface. The first groove 101 and the second groove 102 maintain the same angular position and are perpendicular to the fourth groove 104, so that the initial cutting teeth of the two gear shaping cutters are installed at the same angular position of the gear shaping cutter 1. At the same time, it ensures that the gear shaping cutter does not rotate circumferentially during operation, which facilitates the gear shaping cutter to quickly achieve its initial cutting tooth working position when installed on the machine tool.

[0054] The stroke length L of the herringbone gear 4, the thickness B1 of the positioning hole of the first gear shaper 2, the thickness H0 of the axial positioning sleeve 5, the total thickness of the first gear shaper 2 and the second gear shaper 3 are the same and the axial distance on the gear shaper bar 1 is L0, ensuring that the axial distance L0 ≥ the stroke length L of the herringbone gear 4, the thickness H0 of the axial positioning sleeve 5 is determined by the following calculation formula:

[0055] H0=L0-B1≥L-B1

[0056] In this embodiment, L0 is 72mm, B1 is 14mm, L is 70.5mm, and H0 is 58mm.

[0057] The axial positioning sleeve 5 has two axial keyways 51 on its positioning inner hole. One axial keyway 51 corresponds to the third groove 103 and is used to place the third key 143. The other axial keyway 51 corresponds to the second groove 102 and is used to place the second key 142 to prevent the axial positioning sleeve 5 from rotating. The two axial keyways 51 are arranged at 90° on the inner wall of the positioning inner hole.

[0058] The first gear shaping cutter 2, the second gear shaping cutter 3, the gear shaping cutter shank 1, and the tool axial positioning sleeve 5 are combined into an integrated herringbone gear shaping cutter. The first gear shaping cutter 2 and the second gear shaping cutter 3 are installed in the same direction (the cutting edge faces the outer circle 134 of the front end of the tool shank). At this time, the initial cutting teeth of the two gear shaping cutters have the same angular position.

[0059] When installing the integrated herringbone gear shaping cutter, use the bottom surface of the fourth groove 104 of the middle section 12 of the gear shaping cutter shank 1 as the reference plane for alignment. Set the angular position value of the gear shaping machine cutter spindle to α. Then, rotate the cutter spindle counterclockwise by 90°. The initial working starting angle of the cutting teeth of both the first gear shaping cutter 2 and the second gear shaping cutter 3 will then be γ, where γ = α - 90°. Set the initial cutting tooth working starting angle γ determined by the two gear shaping cutters in the gear shaping machine program.

[0060] In this invention, the first groove 101, the second groove 102, and the third groove 103 are all keyways.

[0061] The symmetry error detection results of the herringbone gear 4 (with symmetry error measured by gear measuring center) produced using the gear shaping cutter of this invention combined with the common gear shaping program on the gear shaping machine are as follows: Figure 11 As shown in the figure, the center section of the herringbone gear 4 has a dimension of +75.2500mm, and the measured symmetry error is 91.5μm, indicating that the symmetry error of the herringbone gear is qualified.

[0062] If either the first gear shaping cutter 2 or the second gear shaping cutter 3 wears out, the rake faces of both cutters used for installation should be reground simultaneously, with each reground layer being the same thickness, to ensure that the two cutters are in the same starting angle position during subsequent use or to reduce the number of adjustment and compensation cutting operations.

[0063] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A gear shaping tool for herringbone gear shaping, comprising a gear shaping tool holder (1) and a gear shaping cutter, wherein the gear shaping cutter is mounted on the gear shaping tool holder (1), characterized in that: The gear shaping cutter includes a first gear shaping cutter (2) and a second gear shaping cutter (3). The gear shaping cutter bar (1) is provided with a mounting part (13). The first gear shaping cutter (2) and the second gear shaping cutter (3) are respectively mounted at both ends of the mounting part (13). The axial distance between the first gear shaping cutter (2) and the second gear shaping cutter (3) is... The stroke length of the shearing gear (4) is L, which satisfies ≥L; The gear shaping tool holder (1) also includes a tool holder part (11) and an intermediate section (12). The tool holder part (11) is mounted on the gear shaping machine spindle. The intermediate section (12) is located between the tool holder part (11) and the mounting part (13). A fourth groove (104) is provided on the outer circumferential surface of the intermediate section (12). The bottom surface of the fourth groove (104) serves as the tool holder alignment reference surface. The intermediate section (12) has a first groove (101) on the end face near the mounting part (13), and the first gear cutter (2) has an end face groove (21) on the end face away from the cutting edge. The first groove (101) and the end face groove (21) correspond to each other and a first key (141) is installed in the space between the first groove (101) and the end face groove (21). The first key (141) is used to prevent the first gear cutter (2) from rotating and to position the initial cutting teeth of the first gear cutter (2). The mounting part (13) has a second groove (102) on its outer peripheral surface. The inner wall of the positioning reference hole of the second gear cutter (3) has a positioning groove (31). The positioning groove (31) and the second groove (102) correspond to each other and a second key (142) is installed in the space between the positioning groove (31) and the second groove (102). The second key (142) is used to prevent the second gear cutter (3) from rotating and to position the initial cutting teeth of the second gear cutter (3). The first key (141) and the second key (142) are in the same angular position on the gear shaping bar (1).

2. The gear shaping tool according to claim 1, characterized in that: The mounting part (13) has an axial positioning sleeve (5) fitted between the first gear cutter (2) and the second gear cutter (3).

3. The gear shaping tool according to claim 2, characterized in that: The mounting part (13) has a third groove (103) on its outer peripheral surface and an axial keyway (51) on its inner peripheral surface. The third groove (103) and the axial keyway (51) correspond to each other and a third key (143) is installed in the space between the third groove (103) and the axial keyway (51). The third key (143) is used to prevent the axial positioning sleeve (5) from rotating.

4. The gear shaping tool according to any one of claims 1 to 3, characterized in that: The first gear cutter (2) and the second gear cutter (3) have opposite rotation directions.

5. The gear shaping tool according to claim 4, characterized in that: The herringbone gear (4) includes an upper helical gear (41) and a lower helical gear (42). The second gear cutter (3) is used to cut the upper helical gear (41) of the herringbone gear (4) and the direction of rotation is opposite to that of the upper helical gear (41). The first gear cutter (2) is used to cut the lower helical gear (42) of the herringbone gear (4) and the direction of rotation is opposite to that of the lower helical gear (42).

6. The gear shaping tool according to any one of claims 1 to 3, characterized in that: The tip circle diameter of the first gear cutter (2) is D1, the tip circle diameter of the second gear cutter (3) is D2, and the tooth height of the herringbone gear (4) is h1, satisfying D1-D2=(2.8~4)×h1.

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