Machining tools and methods for arc tooth cylindrical gear pairs

Abstract

The present invention relates to the technical field of arc tooth cylindrical gear pairs, and provides a method for processing an arc tooth cylindrical gear pair, comprising the following steps: preparing a processing tool for the arc tooth cylindrical gear pair, wherein the processing tool for the arc tooth cylindrical gear pair comprises a first milling cutter, a second milling cutter, and a third milling cutter; using the first milling cutter to process a first gear to be processed; and using the second milling cutter and the third milling cutter to process a second gear to be processed. The processing tool and processing method for the arc tooth cylindrical gear pair provided in an embodiment of the present invention include providing a first milling cutter for processing one of the gears in the gear pair, and providing a second milling cutter and a third milling cutter for processing the other gear in the gear pair; and adjusting the inner blade curvature radius r of the second milling cutter. ib and the outer edge curvature radius r of the third milling cutter ob , the tooth surface contact area of ​​the two gears in the gear pair can be adjusted to achieve the purpose of actively adjusting the tooth surface contact area.

Description

Technical Field

[0001] The present invention relates to the technical field of spiral tooth cylindrical gear pairs, in particular to a machining tool and a machining method for a spiral tooth cylindrical gear pair. Background Art

[0002] A spiral gear pair is a basic mechanism consisting of two meshing spiral gears. A spiral gear is a parallel-axis gear with an arc-shaped tooth profile along the tooth width. During meshing, the two spiral gears are classified as either point-contact or line-contact, depending on the contact pattern of the tooth surfaces.

[0003] Currently, arc gear pairs are typically machined using the same tool on two meshing arc gears. However, this method can only produce point-contact or line-contact arc gear pairs. For example, using a tool such as that described in Publication No. CN1047137A only produces point-contact arc gear pairs; using tools such as those described in Publication No. CN103203647A, Publication No. CN112170974A, Publication No. CN101890540B, or Publication No. CN100335821C only produces line-contact arc gear pairs.

[0004] During the meshing process of the point contact arc tooth cylindrical gear pair, the contact form on the two paired tooth surfaces is local contact, and the contact position is mainly concentrated in the middle section of the tooth width. The contact stress distribution is as follows: Figure 1 As shown in the figure, due to the small contact area of ​​the point contact spiral tooth cylindrical gear pair, the load borne by the local contact area is large during the transmission process, and long-term use can easily cause fatigue wear of the contact area.

[0005] During the meshing process of the line contact arc tooth cylindrical gear pair, the contact form on the two paired tooth surfaces is a curved contact along the tooth width direction, and the contact stress distribution is as follows: Figure 2 Although line-contact arc-tooth cylindrical gear pairs have contact across the entire tooth width and a large contact area, installation errors are prone to occur during the gear pair installation process. This causes the two meshing gears to transition from line contact to tooth edge contact, which can severely wear the gear edges during use and easily lead to large transmission errors, noise, and vibration. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a machining tool and a machining method for a spiral cylindrical gear pair in which the tooth surface contact area can be actively adjusted.

[0007] The technical solution adopted by the present invention to solve the technical problem is as follows: the machining tool for the spiral cylindrical gear pair includes a first milling cutter, a second milling cutter and a third milling cutter;

[0008] The first milling cutter includes a first cutter disc and a plurality of first teeth uniformly distributed on the end surface of the first cutter disc; the first teeth have an inner tooth surface and an outer tooth surface; the outer tooth curvature radius of the first milling cutter is R ob The inner curvature radius of the first milling cutter is R ib The average curvature radius of the first milling cutter is R m ;

[0009] The second milling cutter includes a second cutter disc and a plurality of inner blade teeth evenly distributed on the end surface of the second cutter disc; the inner blade curvature radius of the second milling cutter is r ib ; Among them, R m -πm / 4≤r ib ≤R m +πm / 4; m is the module of the gear being processed;

[0010] The third milling cutter includes a third cutter disc and a plurality of outer blade teeth evenly distributed on the end surface of the third cutter disc; the outer blade curvature radius of the third milling cutter is r ob ; Among them, r ob =2R m -r ib .

[0011] The method for processing a spiral tooth cylindrical gear pair includes the following steps: preparing a processing tool for the spiral tooth cylindrical gear pair; using a first milling cutter to process a first processed gear; and using a second milling cutter and a third milling cutter to process a second processed gear.

[0012] Furthermore, the processing method of the first processed gear includes the following steps:

[0013] S1. Mount a first gear to be processed on a workpiece axis of a processing machine tool; mount a first milling cutter on a tool axis of the processing machine tool; wherein the workpiece axis is arranged parallel to the X direction, the tool axis is arranged parallel to the Y direction, and the X direction is perpendicular to the Y direction; adjust the initial positions of the workpiece axis and the tool axis according to the design parameters of the first gear to be processed;

[0014] S2, controlling the cutter shaft to rotate around its own axis, controlling the workpiece axis to feed along the Y direction, and machining a tooth groove of the first gear to be machined by the first milling cutter;

[0015] S3. After step S2 is completed, the first gear being processed is indexed, and step S2 is repeated until all the tooth grooves of the first gear being processed are processed.

[0016] Furthermore, the processing machine tool is a six-axis CNC gear milling machine.

[0017] Furthermore, in step S1, the first milling cutter is mounted on a cutter shaft of a machining center via a first fixed shaft coaxially fixed to the first cutter head.

[0018] Furthermore, the processing method of the second processed gear includes the following steps:

[0019] K1. Mount the second gear to be processed on the workpiece axis of the processing machine tool; mount the third milling cutter on the tool axis of the processing machine tool; wherein the workpiece axis is parallel to the X direction, the tool axis is parallel to the Y direction, and the X direction is perpendicular to the Y direction;

[0020] K2. Adjust the initial positions of the workpiece axis and the tool axis according to the design parameters of the second gear being machined; the distance between the centerline of the workpiece axis and the centerline of the tool axis in the Z direction is Z3; wherein the Z direction is perpendicular to the X direction and the Y direction respectively;

[0021] K3, controls the cutter shaft to rotate around its own axis, controls the workpiece axis to feed along the Y direction, and then processes the concave tooth surface of a tooth groove of the second gear being processed;

[0022] K4. After step K3 is completed, the second gear to be processed is indexed; then step K3 is repeated until the concave tooth surfaces of all tooth grooves of the second gear to be processed are processed;

[0023] K5. After completing step K4, remove the third milling cutter and install the second milling cutter on the tool spindle of the processing machine tool; control the tool spindle to move along the Z direction so that the distance between the center line of the workpiece axis and the center line of the tool spindle in the Z direction is Z2; where Z2=Z1+E, E=πm / 2-(r ob -r ib );

[0024] K6, controls the cutter shaft to rotate around its own axis, controls the workpiece axis to feed along the Y direction, and then processes the convex tooth surface of a tooth groove of the second gear being processed;

[0025] K7. After step K6 is completed, the second gear to be processed is indexed; then step K6 is repeated until the convex tooth surfaces of all tooth grooves of the second gear to be processed are processed.

[0026] Furthermore, in step K2, the center line of the third milling cutter is coplanar with the middle cross section of the tooth width of the second gear being processed.

[0027] Furthermore, the processing machine tool is a six-axis CNC gear milling machine.

[0028] Furthermore, in step K1, the third milling cutter is mounted on a cutter shaft of the machining center via a third fixed shaft coaxially fixed to the third cutter head.

[0029] Furthermore, in step K5, the second milling cutter is mounted on a cutter shaft of the machining center via a second fixed shaft coaxially fixed to the second cutter head.

[0030] The beneficial effects of the present invention are as follows: the processing tool and processing method of the arc tooth cylindrical gear pair provided by the embodiment of the present invention are used to process one of the gears in the gear pair by setting a first milling cutter, and to process the other gear in the gear pair by setting a second milling cutter and a third milling cutter; by adjusting the inner blade curvature radius r of the second milling cutter, the inner blade curvature radius r of the second milling cutter is increased, and the inner blade curvature radius r of the second milling cutter is increased. ib and the outer edge curvature radius r of the third milling cutter ob , the tooth surface contact area of ​​the two gears in the gear pair can be adjusted to achieve the purpose of actively adjusting the tooth surface contact area. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art; obviously, the drawings described below are only some embodiments recorded in the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 It is the contact stress diagram of the point contact spiral cylindrical gear pair when meshing;

[0033] Figure 2 It is the contact stress diagram of the line contact spiral tooth cylindrical gear pair when meshing;

[0034] Figure 3 is a structural schematic diagram of a first milling cutter provided in an embodiment of the present invention;

[0035] Figure 4 is a schematic structural diagram of a second milling cutter provided in an embodiment of the present invention;

[0036] Figure 5 is a schematic structural diagram of a third milling cutter provided in an embodiment of the present invention;

[0037] Figure 6 2 is a schematic structural diagram of machining a tooth groove of a first gear to be machined by a first milling cutter in an embodiment of the present invention;

[0038] Figure 7 yes Figure 6 Middle AA section view;

[0039] Figure 8 3 is a schematic structural diagram of machining a concave tooth surface of a tooth groove of a second gear to be machined by a third milling cutter in an embodiment of the present invention;

[0040] Figure 9 yes Figure 8Middle BB cross-section;

[0041] Figure 10 3 is a schematic structural diagram of machining a convex tooth surface of a tooth groove of a second gear to be machined by a second milling cutter in an embodiment of the present invention;

[0042] Figure 11 yes Figure 10 Middle CC section view;

[0043] Figure 12 Schematic diagram of the structure of a processing machine tool provided by an embodiment of the present invention;

[0044] Figure 13 Schematic diagram of the contact area obtained by performing contact analysis on the gear pair in Example 1 of the present invention;

[0045] Figure 14 is a schematic diagram of the contact area obtained by performing contact analysis on the gear pair in Example 2 of the present invention;

[0046] Figure 15 Schematic diagram of the contact area obtained by performing contact analysis on the gear pair in Example 3 of the present invention.

[0047] The reference numbers in the figure are: 1-first milling cutter, 2-second milling cutter, 3-third milling cutter, 4-first machined gear, 5-second machined gear, 6-processing machine tool, 11-first cutter disc, 12-first cutter teeth, 13-first fixed shaft, 21-second cutter disc, 22-inner edge cutter teeth, 23-second fixed shaft, 31-third cutter disc, 32-outer edge cutter teeth, 33-third fixed shaft, 61-workpiece axis, 62-cutter axis. DETAILED DESCRIPTION

[0048] To help those skilled in the art better understand the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments. It is apparent that the embodiments described are only a portion of the embodiments of the present invention, not all of them. The embodiments of the present invention and the features therein may be combined with each other unless there is a conflict.

[0049] Figure 3 is a structural schematic diagram of a first milling cutter provided in an embodiment of the present invention; Figure 4 is a schematic structural diagram of a second milling cutter provided in an embodiment of the present invention; Figure 5 It is a schematic structural diagram of a third milling cutter provided in an embodiment of the present invention.

[0050] See also Figures 3 to 5 The machining tool for the spiral cylindrical gear pair provided by the embodiment of the present invention includes a first milling cutter 1, a second milling cutter 2 and a third milling cutter 3;

[0051] The first milling cutter 1 comprises a first cutter disc 11 and a plurality of first teeth 12 evenly distributed on the end surface of the first cutter disc 11; the first teeth 12 have an inner tooth surface and an outer tooth surface; the outer edge curvature radius of the first milling cutter 1 is R ob ; The inner edge curvature radius of the first milling cutter 1 is R ib The average curvature radius of the first milling cutter 1 is R m ;

[0052] The second milling cutter 2 includes a second cutter disc 21 and a plurality of inner blade teeth 22 evenly distributed on the end surface of the second cutter disc 21; the inner blade curvature radius of the second milling cutter 2 is r ib ; Among them, R m -πm / 4≤r ib ≤R m +πm / 4; m is the module of the gear being processed;

[0053] The third milling cutter 3 comprises a third cutter disc 31 and a plurality of outer blade teeth 32 evenly distributed on the end surface of the third cutter disc 31; the outer blade curvature radius of the third milling cutter 3 is r ob ; Among them, r ob =2R m -r ib .

[0054] The tool for machining a spiral cylindrical gear pair provided in an embodiment of the present invention includes a first milling cutter 1, a second milling cutter 2, and a third milling cutter 3. The first milling cutter 1 is used to machine one of the gears in the gear pair, and the second milling cutter 2 and the third milling cutter 3 are used to machine the other gear in the gear pair.

[0055] See also Figure 3 The first milling cutter 1 includes a first circular cutter disc 11, a plurality of first cutting teeth 12 circumferentially evenly distributed and mounted on the lower end surface of the first cutter disc 11 with the center line of the first cutter disc 11 as the center, and a first fixed shaft 13 coaxially fixed on the upper end surface of the first cutter disc 11. The first cutting tooth 12 has an inner tooth surface and an outer tooth surface; the shape of the inner tooth surface is adapted to the shape of the convex tooth surface of the tooth groove, and the convex tooth surface of the tooth groove is processed by the inner tooth surface; the shape of the outer tooth surface is adapted to the shape of the concave tooth surface of the tooth groove, and the concave tooth surface of the tooth groove is processed by the outer tooth surface. The outer blade curvature radius of the first milling cutter 1 is R ob ; R ob Refers to the distance from the position on the outer edge of the first tooth 12 corresponding to the pitch circle of the gear being processed to the center line of the first cutter head 11. The inner edge curvature radius of the first milling cutter 1 is R ib ; R ibIt refers to the distance from the position on the inner tooth surface of the first tooth 12 corresponding to the pitch circle of the gear being processed to the center line of the first cutter head 11. The average curvature radius of the first milling cutter 1 is R m ; R m Refers to the distance from the center line of the first tooth 12 to the center line of the first cutter head 11. In this embodiment, the parameter R ib 、R ob 、R m The value of is determined by the tool manufacturer's standard and is not specifically limited here. For example, R ib =R m -πm / 4, R ob +R ib =2R m .

[0056] See also Figure 4 The second milling cutter 2 includes a circular second cutter disc 21, a plurality of inner blade teeth 22 uniformly distributed around the circumference of the second cutter disc 21 and centered on the center line of the second cutter disc 21, and a second fixed shaft 23 coaxially fixed to the upper end surface of the second cutter disc 21. The inner blade teeth 22 have an inner blade surface, the shape of which matches the shape of the convex tooth surface of the tooth groove, and the convex tooth surface of the tooth groove is processed by the inner blade surface. The inner blade curvature radius of the second milling cutter 2 is r ib ; r ib Refers to the distance from the position on the inner tooth surface of the second milling cutter 2 corresponding to the pitch circle of the gear being processed to the center line of the second cutter head 21. m -πm / 4≤r ib ≤R m +πm / 4; m is the module of the gear being processed.

[0057] See also Figure 5 The third milling cutter 3 includes a circular third cutter disc 31, a plurality of outer blade teeth 32 evenly distributed around the circumference of the third cutter disc 31 and centered on the center line of the third cutter disc 31, and a third fixed shaft 33 coaxially fixed to the upper end surface of the third cutter disc 31. The outer blade teeth 32 have an outer blade surface, the shape of which matches the shape of the concave tooth surface of the tooth groove, and the concave tooth surface of the tooth groove is processed by the outer blade surface. The outer blade curvature radius of the third milling cutter 3 is r ob ; r ob Refers to the distance from the position on the outer tooth surface of the outer tooth 32 corresponding to the pitch circle of the gear being processed to the center line of the third cutter head 31. ob =2R m -r ib .

[0058] An embodiment of the present invention provides a method for machining a spiral cylindrical gear pair, wherein the spiral cylindrical gear pair includes a first machined gear 4 and a second machined gear 5 for meshing with each other; the method includes the following steps: preparing a machining tool for the spiral cylindrical gear pair; using a first milling cutter 1 to machine the first machined gear 4; and using a second milling cutter 2 and a third milling cutter 3 to machine the second machined gear 5.

[0059] Figure 6 2 is a schematic structural diagram of machining a tooth groove of a first gear to be machined by a first milling cutter in an embodiment of the present invention; Figure 7 yes Figure 6 Middle AA section view.

[0060] See also Figure 6 、 Figure 7 The processing method of the first processed gear 4 provided in the embodiment of the present invention includes the following steps:

[0061] S1. Mount the first machined gear 4 on the workpiece shaft 61 of the machining machine 6; mount the first milling cutter 1 on the cutter shaft 62 of the machining machine 6; wherein the workpiece shaft 61 is arranged parallel to the X direction, the cutter shaft 62 is arranged parallel to the Y direction, and the X direction is perpendicular to the Y direction; adjust the initial positions of the workpiece shaft 61 and the cutter shaft 62 according to the design parameters of the first machined gear 4;

[0062] S2, controlling the cutter shaft 62 to rotate around its own axis, controlling the workpiece shaft 61 to feed along the Y direction, and machining a tooth groove of the first gear 4 by the first milling cutter 1;

[0063] S3. After step S2 is completed, the first processed gear 4 is indexed, and step S2 is repeated until all the tooth grooves of the first processed gear 4 are processed.

[0064] The processing machine 6 is a device for processing spiral cylindrical gears. In the embodiment of the present invention, the processing machine 6 is preferably a six-axis CNC gear milling machine. Of course, the processing machine 6 can also be other commonly used machine tools, as long as it can process spiral cylindrical gears, and no specific limitation is made here.

[0065] Figure 12 It is a structural schematic diagram of a processing machine tool provided by an embodiment of the present invention.

[0066] See also Figure 12, the X-direction, Y-direction and Z-direction in the figure are three mutually perpendicular directions, among which the X-direction and the Y-direction are two horizontal directions, and the Z-direction is a vertical direction. The processing machine tool 6 has a horizontally arranged workpiece shaft 61 and a cutter shaft 62. Among them, the workpiece shaft 61 can rotate around its own axis, and the workpiece shaft 61 can also rotate around a vertical center line in the horizontal plane, and the workpiece shaft 61 can also reciprocate along the Y-direction. The cutter shaft 62 can rotate around its own axis, and the cutter shaft 62 is set parallel to the Y-direction, and the cutter shaft 62 can reciprocate along the X-direction and the Z-direction respectively. During operation, the gear to be processed is mounted on the workpiece shaft 61, and the arc tooth milling cutter is mounted on the cutter shaft 62.

[0067] The following combination Figure 6 、 Figure 7 、 Figure 12 The processing method of the first processed gear 4 provided in the embodiment of the present invention is described in detail.

[0068] In step S1, the first gear 4 to be machined is mounted on the workpiece shaft 61 of the machining center 6. This ensures that the first gear 4 to be machined is coaxial with the workpiece shaft 61. This allows the workpiece shaft 61 to drive the first gear 4 to rotate about its own axis. The position of the workpiece shaft 61 is adjusted so that its axis is parallel to the X-axis.

[0069] The first milling cutter 1 is mounted on the cutter shaft 62 of the machining center 6. Specifically, the first fixed shaft 13 is mounted on the cutter shaft 62 of the machining center 6 to ensure that the first milling cutter 1 is coaxial with the cutter shaft 62. Thus, the cutter shaft 62 drives the first milling cutter 1 to rotate about its own axis. The cutter shaft 62 is parallel to the Y direction. Therefore, when the workpiece axis 61 is adjusted to be parallel to the X direction, the axis of the first gear 4 being machined and the axis of the first milling cutter 1 are ensured to be perpendicular to each other.

[0070] Adjust the initial positions of the workpiece axis 61 and the cutter axis 62 according to the design parameters of the first machined gear 4. Specifically, adjust the positions of the cutter axis 62 in the X and Z directions according to the design parameters of the first machined gear 4. For example, see Figure 6 By adjusting the positions of the cutter shaft 62 in the X and Z directions, the center line of the first milling cutter 1 can be located below the center line of the first machined gear 4, and the first tooth 12 of the first milling cutter 1 is 180° to the left of the first machined gear 4. After the adjustment is completed, the distance between the center line of the first machined gear 4 and the center line of the first milling cutter 1 in the Z direction is Z1.

[0071] Of course, as another embodiment, after the initial positions of the workpiece axis 61 and the cutter axis 62 are adjusted, the center line of the first milling cutter 1 may also be located above the center line of the first machined gear 4, which is not specifically limited here.

[0072] Preferably, after the initial positions of the workpiece axis 61 and the cutter axis 62 are adjusted, the center line of the first milling cutter 1 is coplanar with the middle section of the tooth width of the first machined gear 4, see Figure 7 , so that an arc-shaped tooth groove that is symmetrical about the middle section of the tooth width can be processed.

[0073] In step S2, the processing machine 6 is started to process the first gear 4. Figure 6 , control the cutter shaft 62 to rotate around its own axis, thereby driving the first milling cutter 1 to rotate and controlling the workpiece shaft 61 to feed along the Y direction; and then the first milling cutter 1 processes a complete tooth groove at a position 180° to the left of the gear 1 being processed, that is, both the concave tooth surface and the convex tooth surface of the tooth groove are processed, such as Figure 7 As shown, the radius of the concave tooth surface of the tooth groove at the pitch circle position of the gear is R ob The radius of the convex tooth surface of the tooth groove at the pitch circle position of the gear is R ib .

[0074] In step S3 , after one tooth groove 11 is machined on the first machined gear 4 , the first machined gear 4 is indexed, and step S2 is repeated to sequentially machine the remaining tooth grooves on the first machined gear 4 .

[0075] Figure 8 3 is a schematic structural diagram of machining a concave tooth surface of a tooth groove of a second gear to be machined by a third milling cutter in an embodiment of the present invention;

[0076] Figure 9 yes Figure 8 Middle BB cross-section; Figure 10 3 is a schematic structural diagram of machining a convex tooth surface of a tooth groove of a second gear to be machined by a second milling cutter in an embodiment of the present invention; Figure 11 yes Figure 10 Middle CC section view.

[0077] See also Figures 8 to 11 The processing method of the second processed gear 5 provided in the embodiment of the present invention includes the following steps:

[0078] K1. Mount the second gear 5 on the workpiece shaft 61 of the machining center 6; mount the third milling cutter 3 on the cutter shaft 62 of the machining center 6; wherein the workpiece shaft 61 is parallel to the X direction, the cutter shaft 62 is parallel to the Y direction, and the X direction is perpendicular to the Y direction;

[0079] K2. Adjust the initial positions of the workpiece axis 61 and the cutter axis 62 according to the design parameters of the second gear 5 to be machined; the distance between the centerline of the workpiece axis 61 and the centerline of the cutter axis 62 in the Z direction is Z3; wherein the Z direction is perpendicular to the X direction and the Y direction respectively;

[0080] K3, controls the cutter shaft 62 to rotate around its own axis, controls the workpiece shaft 61 to feed along the Y direction, and thereby machines a concave tooth surface of a tooth groove of the second gear 5 to be machined;

[0081] K4. After step K3 is completed, the second gear 5 to be processed is indexed; then step K3 is repeated until the concave tooth surfaces of all tooth grooves of the second gear 5 to be processed are processed;

[0082] K5. After step K4 is completed, remove the third milling cutter 3 and install the second milling cutter 2 on the cutter shaft 62 of the processing machine tool 6; control the cutter shaft 62 to move along the Z direction so that the distance between the center line of the workpiece axis 61 and the center line of the cutter shaft 62 in the Z direction is Z2; where Z2 = Z1 + E, E = πm / 2-(r ob -r ib );

[0083] K6 controls the cutter shaft 62 to rotate around its own axis, controls the workpiece shaft 61 to feed along the Y direction, and thereby processes a convex tooth surface of a tooth groove of the second gear 5 to be processed;

[0084] K7. After step K6 is completed, the second processed gear 5 is indexed; and then step K6 is repeated until the convex tooth surfaces of all tooth grooves of the second processed gear 5 are processed.

[0085] The following combination Figures 8 to 12 The processing method of the second processed gear 5 provided in the embodiment of the present invention is described in detail.

[0086] In step K1, the second gear 5 is mounted on the workpiece shaft 61 of the machining center 6. This ensures that the second gear 5 is coaxial with the workpiece shaft 61. This allows the workpiece shaft 61 to drive the second gear 5 to rotate about its own axis. The position of the workpiece shaft 61 is adjusted so that its axis is parallel to the X-axis.

[0087] The third milling cutter 3 is mounted on the cutter shaft 62 of the machining center 6. Specifically, the third fixed shaft 33 is mounted on the cutter shaft 62 of the machining center 6, ensuring that the third milling cutter 3 is coaxial with the cutter shaft 62. Thus, the cutter shaft 62 drives the third milling cutter 3 to rotate about its own axis. The cutter shaft 62 is parallel to the Y direction, so when the workpiece axis 61 is adjusted to be parallel to the X direction, the axis of the second gear 5 being machined and the axis of the third milling cutter 3 are ensured to be perpendicular to each other.

[0088] In step K2, the initial positions of the workpiece axis 61 and the cutter axis 62 are adjusted according to the design parameters of the second machined gear 5. Specifically, the positions of the cutter axis 62 in the X and Z directions are adjusted according to the design parameters of the second machined gear 5. For example, see Figure 8By adjusting the positions of the cutter shaft 62 in the X and Z directions, the center line of the third milling cutter 3 can be located below the center line of the second machined gear 5, and the outer edge teeth 32 of the third milling cutter 3 are 180° to the left of the second machined gear 5. After the adjustment is completed, the distance between the center line of the second machined gear 5 and the center line of the third milling cutter 3 in the Z direction is Z3.

[0089] Of course, as another embodiment, after the initial positions of the workpiece axis 61 and the cutter axis 62 are adjusted, the center line of the third milling cutter 3 may also be located above the center line of the second machined gear 5, which is not specifically limited here.

[0090] Preferably, after the initial positions of the workpiece axis 61 and the cutter axis 62 are adjusted, the center line of the third milling cutter 3 is coplanar with the middle section of the tooth width of the second processed gear 5, see Figure 9 , so that an arc-shaped tooth groove that is symmetrical about the middle section of the tooth width can be processed.

[0091] In step K3, the processing machine tool 6 is started to process the second gear 5. Figure 8 , control the cutter shaft 62 to rotate around its own axis, thereby driving the third milling cutter 3 to rotate, control the workpiece shaft 61 to feed along the Y direction, and then use the third milling cutter 3 to process a concave tooth surface of the tooth groove at a position 180° on the left side of the second gear 5 to be processed, as shown in FIG. Figure 9 As shown, the radius of the concave tooth surface of the tooth groove at the pitch circle position of the gear is r ob .

[0092] In step K4, after the concave tooth surface of one tooth groove is machined on the second machined gear 5, the second machined gear 5 is indexed and step K3 is repeated to sequentially machine the concave tooth surfaces of the remaining tooth grooves on the second machined gear 5.

[0093] In step K5, after the concave tooth surfaces of all tooth grooves on the second gear 5 are machined, the third milling cutter 3 is removed. At this time, the position of the workpiece axis 61 in the Y and Z directions must be maintained, and the position of the cutter shaft 62 in the X and Z directions must be maintained. Then, the second milling cutter 2 is installed on the cutter shaft 62 of the processing machine 6. Specifically, the second fixed shaft 23 is installed on the cutter shaft 62 of the processing machine 6 to ensure that the second milling cutter 2 is coaxial with the cutter shaft 62. In this way, the second milling cutter 2 is driven to rotate about its own axis by the cutter shaft 62.

[0094] Control the knife axis 62 to move along the Z direction so that the distance between the center line of the workpiece axis 61 and the center line of the knife axis 62 in the Z direction is Z2; wherein Z2=Z1+E,E=πm / 2-(r ob -r ib For details, see Figure 10Since the center line of the second milling cutter 2 is below the center line of the second machined gear 5, it is sufficient to control the cutter shaft 62 to move downward E along the Z direction. At this time, the inner edge tooth 22 of the second milling cutter 2 is facing the 180° left side of the second machined gear 5, and the distance between the center line of the second machined gear 5 and the center line of the second milling cutter 2 in the Z direction is Z2.

[0095] Of course, when the center line of the third milling cutter 3 in step K1 is located above the center line of the second gear 5 to be processed, then in step K5, the cutter shaft 62 should be controlled to move upward E along the Z direction.

[0096] In step K6, the processing machine 6 is started to process the second gear 5. Figure 10 , control the cutter shaft 62 to rotate around its own axis, thereby driving the second milling cutter 2 to rotate, control the workpiece shaft 61 to feed along the Y direction, and then use the second milling cutter 2 to process a convex tooth surface of the tooth groove at the 180° position on the left side of the second gear 5 to be processed, as shown in FIG. Figure 11 As shown, the radius of the convex tooth surface of the tooth groove at the pitch circle position of the gear is r ib , thus completing the processing of a tooth groove.

[0097] In step K7, after the convex tooth surface of one tooth groove is machined on the second machined gear 5, the second machined gear 5 is indexed and step K6 is repeated to sequentially machine the convex tooth surfaces of the remaining tooth grooves on the second machined gear 5.

[0098] The processing method of the arc tooth cylindrical gear pair provided in the embodiment of the present invention can use one processing machine tool 6 to complete the processing of two arc tooth cylindrical gears, or can use two processing machine tools 6 to complete the processing of two arc tooth cylindrical gears, and no specific limitation is made here. When the number of processing machine tools 6 is one, the first processed gear 4 can be processed first, and then the second processed gear 5 can be processed; or the second processed gear 5 can be processed first, and then the first processed gear 4 can be processed. When the number of processing machine tools 6 is two, one of the processing machine tools 6 is used to process the first processed gear 4, and the other processing machine tool 6 is used to process the second processed gear 5; the first processed gear 4 and the second processed gear 5 can be processed simultaneously, or they can be processed one after another, and no specific limitation is made here.

[0099] Example 1:

[0100] The tooth width of the two gears of the spiral cylindrical gear pair is W = 30 mm, and the module is m = 4 mm;

[0101] The outer edge curvature radius of the first milling cutter 1 is R ob =43.14159mm; the inner edge curvature radius of the first milling cutter 1 is Rib =36.85841mm; the average curvature radius of the first milling cutter 1 is R m =40mm;

[0102] The inner edge curvature radius of the second milling cutter 2 is r ib =R m -πm / 4=36.85841mm;

[0103] The outer edge curvature radius of the third milling cutter 3 is r ob =2R m -r ib =43.14159mm;

[0104] Cutter offset: E=πm / 2-(r ob -r ib )=0;

[0105] The first milling cutter 1 is used to machine the first gear 4, and the second milling cutter 2 and the third milling cutter 3 are used to machine the second gear 5. After the machining is completed, the gear tooth contact analysis shows that the contact area at a certain contact position on one of the tooth surfaces when the two gears are meshing is as follows: Figure 13 As shown, Figure 13 The area where the middle ellipse is located is the contact area. The contact area is mainly concentrated in the middle section of the tooth width and belongs to a point contact arc tooth cylindrical gear pair.

[0106] Example 2:

[0107] The tooth width of the two gears of the spiral cylindrical gear pair is W = 30 mm, and the module is m = 4 mm;

[0108] The outer edge curvature radius of the first milling cutter 1 is R ob =43.14159mm; the inner edge curvature radius of the first milling cutter 1 is R ib =36.85841mm; the average curvature radius of the first milling cutter 1 is R m =40mm;

[0109] The inner edge curvature radius of the second milling cutter 2 is r ib =42.9172mm;

[0110] The outer edge curvature radius of the third milling cutter 3 is r ob =2R m -r ib =37.0828mm;

[0111] Cutter offset: E=πm / 2-(r ob -r ib )=12.11758mm;

[0112] The first milling cutter 1 is used to machine the first gear 4, and the second milling cutter 2 and the third milling cutter 3 are used to machine the second gear 5. After the machining is completed, the gear tooth contact analysis shows that the contact area at a certain contact position on one of the tooth surfaces when the two gears are meshing is as follows: Figure 14 As shown, Figure 14 The area where the middle ellipse is located is the contact area. The width of the contact area is approximately 5 / 8 of the tooth width, which is larger than the contact width of the point contact arc tooth cylindrical gear pair and smaller than the contact width of the line contact arc tooth cylindrical gear pair.

[0113] Example 3:

[0114] The tooth width of the two gears of the spiral cylindrical gear pair is W = 30 mm, and the module is m = 4 mm;

[0115] The outer edge curvature radius of the first milling cutter 1 is R ob =43.14159mm; the inner edge curvature radius of the first milling cutter 1 is R ib =36.85841mm; the average curvature radius of the first milling cutter 1 is R m =40mm;

[0116] The inner edge curvature radius of the second milling cutter 2 is r ib =R m +πm / 4=43.14159mm;

[0117] The outer edge curvature radius of the third milling cutter 3 is r ob =2R m -r ib =36.85841mm;

[0118] Cutter offset: E=πm / 2-(r ob -r ib )=12.56636mm;

[0119] The first milling cutter 1 is used to machine the first gear 4, and the second milling cutter 2 and the third milling cutter 3 are used to machine the second gear 5. After the machining is completed, the gear tooth contact analysis shows that the contact area at a certain contact position on one of the tooth surfaces when the two gears are meshing is as follows: Figure 15 As shown in the figure, the width of the contact area is equal to the tooth width, which belongs to a line contact arc tooth cylindrical gear pair with contact in the entire tooth width direction.

[0120] The embodiment of the present invention provides a tool and method for machining a spiral cylindrical gear pair, wherein a first milling cutter 1 is provided to machine one of the gears in the gear pair, and a second milling cutter 2 and a third milling cutter 3 are provided to machine the other gear in the gear pair; and an inner blade curvature radius r of the second milling cutter 2 is adjusted. iband the outer edge curvature radius r of the third milling cutter 3 ob , the tooth surface contact area of ​​the two gears in the gear pair can be adjusted to achieve the purpose of actively adjusting the tooth surface contact area, so as to design different gear pairs according to different working conditions. And from Examples 1-3, it can be seen that the inner edge curvature radius r of the second milling cutter 2 ib The larger the value, the wider the contact area of ​​the processed spiral cylindrical gear pair.

[0121] The embodiment of the present invention provides a processing tool and a processing method for a spiral cylindrical gear pair. m -πm / 4 <r ib <R m +πm / 4, an arc tooth cylindrical gear pair with a contact area width between the contact area widths of a point contact arc tooth cylindrical gear pair and a line contact arc tooth cylindrical gear pair can be processed. Compared with the existing point contact arc tooth cylindrical gear pair, the width of the contact area is increased, the load borne by the contact area is reduced, and the service life of the gear pair is increased. Compared with the existing line contact arc tooth cylindrical gear pair, contact in the entire tooth width direction is avoided. In this way, when an installation error occurs in the gear pair during installation, the phenomenon of tooth edge contact can be prevented. During use, transmission errors, noise and vibration caused by gear edge wear are avoided, thereby improving the reliability of the gear pair transmission.

[0122] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for processing a spiral cylindrical gear pair, characterized in that: The method comprises the following steps: preparing a first milling cutter (1), a second milling cutter (2), and a third milling cutter (3); using the first milling cutter (1) to process a first gear to be processed (4); and using the second milling cutter (2) and the third milling cutter (3) to process a second gear to be processed (5), wherein: The first milling cutter (1) comprises a first cutter disc (11) and a plurality of first cutter teeth (12) uniformly distributed on the circumference of the first cutter disc (11) and mounted on the end surface of the first cutter disc (11); the first cutter teeth (12) have an inner tooth surface and an outer tooth surface; the outer edge curvature radius of the first milling cutter (1) is The inner edge curvature radius of the first milling cutter (1) is The average curvature radius of the first milling cutter (1) is ; The second milling cutter (2) comprises a second cutter disc (21) and a plurality of inner blade teeth (22) uniformly distributed on the circumference of the second cutter disc (21) and mounted on the end surface of the second cutter disc (21); the inner blade curvature radius of the second milling cutter (2) is ;in, ; is the module of the gear being machined; The third milling cutter (3) comprises a third cutter disc (31) and a plurality of outer blade teeth (32) uniformly distributed on the end surface of the third cutter disc (31); the outer blade curvature radius of the third milling cutter (3) is ;in, .

2. The method for processing a spiral cylindrical gear pair according to claim 1, characterized in that: A method for processing a first processed gear (4) comprises the following steps: S1. Mounting the first gear to be processed (4) on the workpiece axis (61) of the processing machine tool (6); mounting the first milling cutter (1) on the cutter axis (62) of the processing machine tool (6); wherein the workpiece axis (61) is arranged parallel to the X direction, the cutter axis (62) is arranged parallel to the Y direction, and the X direction is perpendicular to the Y direction; adjusting the position of the cutter axis (62) in the X direction and the Z direction according to the design parameters of the first gear to be processed (4) so ​​that the center line of the first milling cutter (1) is located below or above the center line of the first gear to be processed (4), and the first tooth (12) of the first milling cutter (1) is located 180° to the left of the first gear to be processed (4); after the adjustment is completed, the distance between the center line of the first gear to be processed (4) and the center line of the first milling cutter (1) in the Z direction is Z1, wherein the Z direction is perpendicular to both the X direction and the Y direction; S2, controlling the cutter shaft (62) to rotate about its own axis, controlling the workpiece shaft (61) to feed along the Y direction, and machining a tooth groove of the first machined gear (4) by the first milling cutter (1); S3. After step S2 is completed, the first processed gear (4) is indexed, and step S2 is repeated until all tooth grooves of the first processed gear (4) are processed.

3. The method for processing a spiral cylindrical gear pair according to claim 2, characterized in that: The processing machine tool (6) is a six-axis CNC gear milling machine.

4. The method for machining a spiral cylindrical gear pair according to claim 2, wherein: In step S1, the first milling cutter (1) is mounted on a cutter shaft (62) of a machining machine (6) via a first fixed shaft (13) coaxially fixed to a first cutter disc (11).

5. The method for machining a spiral cylindrical gear pair according to claim 2, wherein: The processing method of the second processed gear (5) comprises the following steps: K1. Mount the second gear to be processed (5) on the workpiece shaft (61) of the processing machine tool (6); mount the third milling cutter (3) on the tool shaft (62) of the processing machine tool (6); wherein the workpiece shaft (61) is arranged parallel to the X direction, the tool shaft (62) is arranged parallel to the Y direction, and the X direction is perpendicular to the Y direction; K2, adjusting the initial positions of the workpiece axis (61) and the tool axis (62) according to the design parameters of the second processed gear (5); the distance between the center line of the workpiece axis (61) and the center line of the tool axis (62) in the Z direction is Z3; wherein the Z direction is perpendicular to the X direction and the Y direction respectively; K3, controls the cutter shaft (62) to rotate around its own axis, controls the workpiece shaft (61) to feed along the Y direction, and thereby processes a concave tooth surface of a tooth groove of the second processed gear (5); K4. After step K3 is completed, the second processed gear (5) is indexed; then step K3 is repeated until the concave tooth surfaces of all tooth grooves of the second processed gear (5) are processed; K5. After step K4 is completed, the third milling cutter (3) is removed and the second milling cutter (2) is installed on the cutter shaft (62) of the processing machine tool (6); the cutter shaft (62) is controlled to move along the Z direction so that the distance between the center line of the workpiece axis (61) and the center line of the cutter shaft (62) in the Z direction is Z2; wherein Z2=Z1+E, , where E is the cutterhead offset; K6, controls the cutter shaft (62) to rotate around its own axis, controls the workpiece shaft (61) to feed along the Y direction, and thereby processes a convex tooth surface of a tooth groove of the second processed gear (5); K7. After step K6 is completed, the second processed gear (5) is indexed; and step K6 is repeated until the convex tooth surfaces of all tooth grooves of the second processed gear (5) are processed.

6. The method for machining a spiral cylindrical gear pair according to claim 5, characterized in that: In step K2, the center line of the third milling cutter (3) is coplanar with the middle section of the tooth width of the second processed gear (5).

7. The method for machining a spiral cylindrical gear pair according to claim 5, characterized in that: The processing machine tool (6) is a six-axis CNC gear milling machine.

8. The method for machining a spiral cylindrical gear pair according to claim 5, characterized in that: In step K1, the third milling cutter (3) is mounted on a cutter shaft (62) of a machining machine (6) via a third fixed shaft (33) coaxially fixed to a third cutter disc (31).

9. The method for machining a spiral cylindrical gear pair according to claim 5, characterized in that: In step K5, the second milling cutter (2) is mounted on the cutter shaft (62) of the machining center (6) via a second fixed shaft (23) coaxially fixed to the second cutter disc (21).

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