Forming gear grinding method for simultaneously grinding multiple tooth grooves of internal gear

Abstract

The invention belongs to the field of involute gear machining, and particularly relates to a forming gear grinding method for simultaneously grinding multiple tooth grooves of an internal gear, and a grinding wheel for grinding the internal gear is a combined grinding wheel comprising a fine grinding wheel and a rough grinding wheel; the internal gear forming grinding wheel gear grinding machine comprises five numerical control shafts, namely machine tool linear shafts X, Y and Z, a grinding wheel swing shaft B and a workpiece rotating shaft C; when a grinding wheel is used on the internal gear forming grinding wheel gear grinding machine to conduct forming grinding on the tooth surface of an internal gear, the grinding wheel synchronously conducts rough grinding and accurate grinding machining on different tooth grooves. According to the method, different rough grinding margins and accurate grinding margins are adopted respectively, the contour shapes of corresponding grinding wheels are calculated, then tooth profiles of rough grinding wheel teeth and accurate grinding wheel teeth are finished at the same time through a grinding wheel finishing tool on the internal gear forming grinding wheel gear grinding machine, and then the tooth surface of an internal gear is ground. The purpose that rough grinding and accurate grinding processes of internal gear forming grinding are conducted at the same time is achieved, and the grinding efficiency and the grinding precision of the internal gear are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of involute gear processing, and in particular relates to a profile gear grinding method for simultaneously grinding multiple tooth grooves of an internal gear. Background Art

[0002] Form grinding of internal gears is a method of precision machining of gears, which is widely used in the field of mechanical manufacturing, especially for high-precision grinding of hardened internal gears. The process of forming grinding of internal gears usually involves rough grinding of the tooth grooves with a forming grinding wheel first. After all the tooth grooves are rough ground, the forming grinding wheel is trimmed with a grinding wheel dressing tool, and then the internal gear is finely ground for each tooth groove to achieve the final geometric accuracy and surface quality. According to the grinding process, the material and particle size of the grinding wheel used for rough grinding and fine grinding should be different. If the same grinding wheel is used for rough grinding first, and then fine grinding is performed after trimming, the tooth surface finish is not high and it is difficult to control the tooth surface waviness. If two different forming grinding wheels are used for rough grinding and fine grinding, errors caused by replacing the grinding wheel will result, which will reduce the grinding efficiency and grinding accuracy of the internal gear. Therefore, a forming grinding method for continuous rough grinding and fine grinding of the tooth grooves of internal gears is needed. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a form grinding method for simultaneously grinding multiple tooth grooves of an internal gear, aiming to solve the problems of low grinding efficiency, low grinding accuracy and low tooth surface quality when rough grinding and fine grinding of tooth grooves are performed separately during form grinding of internal gears.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear, wherein the grinding wheel for grinding the internal gear is a combined grinding wheel including a fine grinding wheel and a rough grinding wheel; the internal gear profile grinding wheel gear grinding machine includes 5 numerical control axes, which are machine tool linear axes X, Y, and Z, a grinding wheel swing axis B, and a workpiece rotation axis C; when the combined grinding wheel is used on the internal gear profile grinding wheel gear grinding machine to perform profile grinding on the tooth surface of the internal gear, the combined grinding wheel synchronously performs rough grinding and fine grinding of different tooth grooves, comprising the following steps:

[0006] Step 1: Establish the tooth surface equation and three-dimensional model of the first tooth groove of the internal gear;

[0007] According to the rotation direction of the internal gear during the grinding process, the installation positions of the fine grinding wheel and the rough grinding wheel are determined; according to the geometric parameters of the internal gear and the outer diameter of the grinding wheel, the gear coordinate system S0 (O0: x0, y0, z0), the fine grinding coordinate system S1 (O1: x1, y1, z1) and the rough grinding coordinate system S2 (O2: x2, y2, z2) are established; the directions of the x0, x1, and x2 coordinate axes are the same, and the axial directions of the x0 and x1 coordinate axes point to the first tooth groove of the internal gear, which is the direction of the inner gear during the grinding process. The tooth depth feed direction; the directions of the y1 and y2 coordinate axes are the same; the angle between the z0 coordinate axis and the y1 and y2 coordinate axes is the internal gear helix angle; the origin O0 of the internal gear coordinate system S0 is at the center of the internal gear circle, and the distance between the origin O1 of the fine grinding wheel coordinate system S1 is the center distance a; in the internal gear coordinate system S1, the final tooth surface equation R1 and the tooth surface three-dimensional model D1 of the first tooth groove of the internal gear are established; the tooth groove adjacent to the first tooth groove of the internal gear is the second tooth groove;

[0008] Step 2: The grinding of the first tooth groove by the fine grinding wheel and the grinding of the second tooth groove by the rough grinding wheel are considered as the initial grinding state; according to the total grinding amount of the internal gear, the grinding amount δ1 of the fine grinding and the grinding amount δ2 of the rough grinding are determined;

[0009] Step 3: Superimpose the tooth surface fine grinding amount δ1 with the final tooth surface three-dimensional model D1 of the internal gear, and establish the tooth surface equation R2 and the corresponding tooth surface three-dimensional model D2 of the second tooth groove of the internal gear corresponding to the rough grinding wheel;

[0010] Step 4: According to the tooth surface equations R1 and R2 and the installation positions of the corresponding fine grinding wheel and rough grinding wheel, respectively solve the coordinate points of the contact lines L1 and L2 between the tooth surface at the first tooth groove and the tooth surface at the second tooth groove and the combined grinding wheel;

[0011] Step 5: Using coordinate transformation, the coordinate points of the contact lines L1 and L2 are respectively converted into the fine grinding wheel coordinate system S1 and the rough grinding wheel coordinate system S2, to obtain the axial cross-sectional profiles of the rough grinding wheel and the fine grinding wheel, and the profiles of the rough grinding wheel and the fine grinding wheel are smoothly connected to form a complete combined grinding profile;

[0012] Step six: Calculate the motion trajectory of the dressing roller according to the axial cross-section profile coordinates of the rough grinding wheel and the fine grinding wheel, and simultaneously perform trimming on the contours of the rough grinding wheel and the fine grinding wheel on the internal gear forming grinding wheel grinding machine, and then use the trimmed combined grinding wheel to grind the tooth surface of the internal gear; first adjust the relative position of the fine grinding wheel and the first tooth groove of the internal gear, starting from the initial contact position of the fine grinding wheel and the rough grinding wheel with the tooth surface of the internal gear, and according to the total grinding allowance, feed multiple times along the x0 coordinate axis direction of the internal gear, and gradually feed to the final grinding position of the internal gear, and then keep the feed position of the combined grinding wheel unchanged, and grind the tooth surfaces corresponding to the remaining tooth grooves of the internal gear according to the motion relationship of the forming grinding, until the grinding of all tooth surfaces of the internal gear is completed.

[0013] Furthermore, in step 1, the fine grinding wheel and the rough grinding wheel are coaxially installed along the grinding wheel axis direction, and the center distance a between the coordinate origin O0 of the internal gear coordinate system S0 and the origin O1 of the fine grinding wheel coordinate system S1 in the direction of the internal gear axis x0 is r0-r1, r0 is the pitch circle radius of the internal gear, and r1 is the pitch circle radius of the fine grinding wheel;

[0014] The rotation direction of the internal gear is viewed from the positive direction of the z0 axis of the internal gear to the negative direction. When the internal gear rotates clockwise, the rough grinding wheel is installed along the negative direction of the z1 axis. If the internal gear rotates counterclockwise, the rough grinding wheel is installed along the positive direction of the z1 axis.

[0015] Furthermore, in step 2, the installation distance d between the fine grinding wheel and the rough grinding wheel on the central axis is determined according to the relative positions of the first tooth groove and the second tooth groove and the rotation direction of the internal gear during the gear grinding process;

[0016]

[0017] In formula (1), β is the helix angle of the internal gear, r0 is the pitch radius of the internal gear, and z is the number of teeth of the internal gear.

[0018] Furthermore, in step 1, the final tooth surface equation R1 of the first tooth groove is expressed as:

[0019]

[0020] In formula (2), the “+” in the “±” sign corresponds to the end face involute of the left tooth surface of the first tooth space, and the “-” in the “±” sign corresponds to the end face involute of the right tooth surface of the first tooth space. b is the base circle radius of the internal gear; μ is the involute angle; σ0 is the tooth gap half angle; matrix M g It is expressed as,

[0021]

[0022] In formula (3), the matrix Mg The “+” in the “±” and the “-” in the “+” sign correspond to the right-handed internal gear tooth surface; the matrix M g The “-” in the “±” and the “+” in the “+” sign correspond to the left-handed internal gear tooth surface; P1 is the internal gear helical parameter, and θ is the rotation angle.

[0023] Furthermore, in step 3, the tooth surface equation R2 at the second tooth groove is expressed as:

[0024]

[0025] In formula (4), r0 is the pitch circle radius of the internal gear, r b is the base circle radius of the internal gear, z is the number of teeth of the internal gear, M g is the matrix M g .

[0026] Furthermore, in step 4, the calculated distribution of the contact lines L1 and L2 satisfies the tooth surface contact condition:

[0027] z x +an y cot∑+(a-x+P1cot∑)n z =0 (5);

[0028] In formula (5), (x, y, z) are the coordinates of the tooth surface contact point obtained according to the tooth surface equation R1 of the first tooth groove of the internal gear or the tooth surface equation R2 of the second tooth groove, (n x , n y , n z ) are the three components of the tooth surface normal vector at the contact point of the internal gear tooth surface, P1 is the internal gear spiral parameter, Σ is the angle between the grinding wheel axis and the internal gear axis, z is the number of internal gear teeth; a=r0-r1, r0 is the pitch circle radius of the internal gear, r1 is the pitch circle radius of the fine grinding wheel.

[0029] Furthermore, in step 5, the transformation matrix from the internal gear coordinate system S0 to the fine grinding wheel coordinate system S1 is:

[0030]

[0031] The transformation matrix from the internal gear coordinate system S0 to the rough grinding wheel coordinate system S2 is:

[0032]

[0033] In the above formula, Σ is the angle between the grinding wheel axis and the internal gear axis, z is the number of teeth of the internal gear, β is the helix angle of the internal gear; a=r0-r1, r0 is the pitch circle radius of the internal gear, and r1 is the pitch circle radius of the fine grinding wheel.

[0034] Furthermore, after the complete combined grinding wheel profile is obtained in step 5, coordinate transformation is performed, and the coordinates of the tooth surface contact lines L1 and L2 calculated in step 4 are transformed into the fine grinding wheel coordinate system S1 and the rough grinding wheel coordinate system S2 to obtain the coordinates of the axial cross-section profile of the fine grinding wheel and the rough grinding wheel; the contact lines L1 and L2 are transformed into the corresponding coordinate system to obtain the axial cross-section coordinates of the combined grinding wheel:

[0035]

[0036] In formula (8), (X j , Y j , Z j ) is the coordinate value of the point on the contact line obtained, R j It is the turning radius formed by the point on the contact line along the axis of the grinding wheel.

[0037] Furthermore, the combined grinding wheel includes one or more rough grinding gears and fine grinding gears; according to processing requirements, the grinding wheel materials of the rough grinding wheel and the fine grinding wheel are the same or different, and the grinding wheel grain sizes of the rough grinding wheel and the fine grinding wheel are different.

[0038] On the basis of the present invention, according to the total grinding amount of the internal gear and the size of the internal gear radius, three or more tooth grooves can also be ground at the same time, and the grinding process can also be divided into different processes such as rough grinding, semi-finishing and fine grinding. For example, the combined grinding wheel includes a first grinding wheel, a second grinding wheel and a third grinding wheel arranged side by side, which are used for rough grinding, semi-finishing and fine grinding respectively. Then, the first tooth groove can be finely ground, the second tooth groove can be semi-finished, and the third tooth groove can be rough ground at the same time, that is, the grinding of three tooth grooves can be performed at the same time. If it is a combination of rough grinding + fine grinding + rough grinding + fine grinding, the grinding of four tooth grooves can be achieved at the same time, but when grinding teeth, the fine grinding wheel at the back needs to skip the tooth grooves that have been finely ground. Similarly, with different combinations of grinding wheels, more tooth grooves can be ground simultaneously, but the fine grinding wheel at the back needs to skip the tooth grooves that have been finely ground.

[0039] It should be noted that this method can be applied to the simultaneous grinding of multiple tooth grooves of internal gears as well as the profile grinding of multiple tooth grooves of external gears. For external gears, the center distance a is adjusted to r0+r1, r0 is adjusted to the pitch radius of the external gear, r1 is adjusted to the pitch radius of the fine grinding wheel, the gear parameter P1 is adjusted to the external gear helix parameter, β is adjusted to the external gear helix angle, and the meanings and formulas of other parameters remain unchanged.

[0040] The working principle of the present invention is to use different rough grinding allowances and fine grinding allowances respectively, calculate the corresponding combined grinding wheel profile, and then use a grinding wheel dressing tool on an internal gear forming grinding wheel gear grinder to simultaneously dress the tooth profiles of the rough grinding wheel teeth and the fine grinding wheel teeth, and then grind the tooth surface of the internal gear to achieve the purpose of simultaneously performing the rough grinding and fine grinding processes of the internal gear forming grinding, thereby improving the grinding efficiency and grinding accuracy of the internal gear. The present invention is applicable to the internal gear being an involute internal helical gear or an involute internal spur gear, and when the helix angle β is zero, it is an internal spur gear.

[0041] The beneficial effects of the present invention are:

[0042] (1) The present invention utilizes a combination of a rough grinding wheel and a fine grinding wheel to simultaneously perform rough grinding and fine grinding on a plurality of tooth grooves of an internal gear. Compared with the step-by-step grinding of conventional profile grinding, there is no need to replace the grinding wheel, and the grinding efficiency is higher.

[0043] (2) The present invention solves the corresponding grinding profile according to the grinding amount of rough grinding and fine grinding, and then uses the dressed grinding wheel to grind the tooth surface of the internal gear, so that the grinding accuracy of the tooth groove tooth surface is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0045] Figure 1 The figure is a schematic diagram of the working state of a workpiece and a combined grinding wheel according to an embodiment of the present invention.

[0046] Figure 2 The figure is a schematic diagram of the installation position of the combined grinding wheel and the grinding wheel shaft interface profile according to an embodiment of the present invention.

[0047] Figure 3 It is a schematic structural diagram of a five-axis CNC internal gear forming grinding wheel gear grinding machine according to an embodiment of the present invention.

[0048] In the figure: the first turntable 101, the internal gear 102, the second guide rail 103, the second slide 104, the first guide rail 105, the first slide 106, the third guide rail 107, the third slide 108, the second turntable 109, the fine grinding wheel 110, the rough grinding wheel 111, the grinding wheel shaft 112, the first tooth groove 200, the second tooth groove 201, the third tooth groove 202, and the shaft cross-section profile 300. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0050] The implementation process of the present invention is described in detail below in combination with the internal gear parameters and processing parameters in Table 1. In this embodiment, the internal gear is an involute internal helical gear.

[0051] Table 1 Gear parameters and processing parameters

[0052]

[0053] Based on the above parameters, calculate the remaining parameters of the internal gear:

[0054] Internal gear tooth half angle σ0 = 0.0393 rad;

[0055] The internal gear pitch circle radius r0 = 85.134 mm;

[0056] The base circle radius of the internal gear r0 = 79.387 mm;

[0057] The axis angle between the internal gear and the combined grinding wheel Σ=1.2217rad(70°);

[0058] Internal gear helical parameter P1 = 233.904 mm;

[0059] The internal gear forming grinding wheel gear grinder used includes 5 CNC movements, namely, the first slide 106 moves along the X direction of the first guide rail 105, the second slide 104 moves along the Y direction of the second guide rail 103, the third slide 108 moves along the Z direction of the third guide rail 107, the first turntable 101 drives the workpiece to rotate around the C axis, and the second turntable 109 drives the grinding wheel to rotate around the B axis. The 5 CNC movements are controlled by the servo motor and CNC system of the internal gear forming grinding wheel gear grinder. In addition, a high-speed motor is also provided on the internal gear forming grinding wheel gear grinder to drive the grinding wheel shaft 112 to produce high-speed rotation, driving the combined grinding wheel to produce grinding movement. The internal gear forming grinding wheel gear grinder is also provided with a grinding wheel dressing mechanism for dressing the axial cross-section profile of the combined grinding wheel.

[0060] A profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear, wherein the grinding wheel for grinding the internal gear 102 is a combined grinding wheel including a fine grinding wheel 110 and a rough grinding wheel 111; when the combined grinding wheel is used on an internal gear profile grinding machine to profile grind the tooth surface of the internal gear 102, the combined grinding wheel simultaneously performs rough grinding and fine grinding of different tooth grooves, comprising the following steps:

[0061] Step 1: Establish the tooth surface equation and three-dimensional model of the first tooth groove of the internal gear;

[0062] like Figures 1 to 3 As shown, according to the rotation direction of the internal gear 102 during the grinding process, the installation positions of the fine grinding wheel 110 and the rough grinding wheel 111 are determined; according to the geometric parameters of the internal gear 102 and the outer diameter of the combined grinding wheel, the gear coordinate system S0 (O0: x0, y0, z0), the fine grinding coordinate system S1 (O1: x1, y1, z1) and the rough grinding coordinate system S2 (O2: x2, y2, z2) are established; the directions of the x0, x1, and x2 coordinate axes are the same, and the axial directions of the x0 and x1 coordinate axes point to the first tooth groove 200 of the internal gear, which is the tooth depth feed direction during the grinding process. ; The directions of the y1 and y2 coordinate axes are the same; the angle between the z0 coordinate axis and the y1 and y2 coordinate axes is the internal gear helix angle; the origin O0 of the internal gear coordinate system S0 is at the center of the internal gear circle, and the distance between the origin O1 of the fine grinding wheel coordinate system S1 is the center distance a; in the internal gear coordinate system S1, the final tooth surface equation R1 and the tooth surface three-dimensional model D1 of the first tooth groove 200 of the internal gear are established; the tooth groove adjacent to the first tooth groove 200 of the internal gear is the second tooth groove 201, and the third tooth groove 202 is adjacent to the second tooth groove 201, and so on;

[0063]

[0064] The upper part “+” of the “±” symbol in the expression represents the end face involute of the left tooth surface at the first tooth groove 200, and the lower part “-” represents the end face involute of the right tooth surface; r b is the base circle radius of the internal gear; μ is the involute angle; σ0 is the tooth gap half angle; matrix M g It is expressed as:

[0065]

[0066] M g In the expression, P1 is the internal gear helical parameter and θ is the rotation angle.

[0067] Step 2: The fine grinding wheel 110 grinds the first tooth groove 200 and the rough grinding wheel 111 grinds the second tooth groove 201 in the initial grinding state; according to the total grinding amount of the internal gear 102, the grinding amount δ1 of the fine grinding and the grinding amount δ2 of the rough grinding are determined; according to the relative position of the first tooth groove 200 and the second tooth groove 201 and the rotation direction of the internal gear 102 during the tooth grinding process, the installation distance d of the fine grinding wheel 110 and the rough grinding wheel 111 on the central axis is determined;

[0068]

[0069] Where z is the number of teeth on the internal gear, β is the helix angle of the internal helical gear, and r0 is the pitch circle radius of the internal helical gear.

[0070] Step 3, superimpose the tooth surface fine grinding amount δ1 with the final tooth surface three-dimensional model D1 of the internal gear, and establish the tooth surface equation R2 and the corresponding tooth surface three-dimensional model D2 of the second tooth groove 201 of the internal gear corresponding to the rough grinding wheel 111;

[0071]

[0072] Step 4: According to the tooth surface equations R1, R2 and the installation positions of the corresponding fine grinding wheel 110 and the rough grinding wheel 111, the contact conditions between the tooth surface and the combined grinding wheel are calculated to obtain the coordinate points of the corresponding contact lines L1 and L2; the contact line between the tool and the helical surface of the workpiece should satisfy that there is a common normal vector n at the contact point between the tool rotating surface and the helical surface, and the relative motion speed at this point should be perpendicular to the common normal line, so the contact condition is:

[0073] v 12 n = 0

[0074] In the above formula, v 12 is the relative velocity at the contact point; n is the common normal vector at the contact point;

[0075] The contact condition equation between the combined grinding wheel and the tooth surface is:

[0076] z x +an y cot∑+(a-x+P1cot∑)n z =0

[0077] In the above formula, x, y, z are the coordinate values ​​of the contact point on the tooth surface equation; n x , n y , n z are the coordinate components of the common normal vector n.

[0078] Step 5: By using coordinate transformation, the coordinate points of the contact lines L1 and L2 are respectively converted into the fine grinding wheel coordinate system S1 and the rough grinding wheel coordinate system S2, and the axial cross-sectional profiles of the rough grinding wheel 111 and the fine grinding wheel 110 are obtained. The profiles of the rough grinding wheel 111 and the fine grinding wheel 110 are smoothly connected to form a complete combined grinding profile; Figure 2 The axial cross-sectional profile 300 of the combined grinding wheel is shown in FIG. 3 ; the transformation matrix from the internal gear coordinate system S0 to the fine grinding wheel coordinate system S1 is:

[0079]

[0080] The transformation matrix from the fine grinding wheel coordinate system S1 to the rough grinding wheel coordinate system S2 is:

[0081]

[0082] The axial cross-sectional profile 300 of the fine grinding wheel 110 and the rough grinding wheel 111 can be obtained. The axial cross-sectional profile coordinate R of a certain point j on the tooth profile j and z j It is expressed as follows:

[0083]

[0084] In the above formula, x j ,y j , z j is the coordinate value of a point j on the contact line solved according to the contact condition equation, R j It is the turning radius formed by the point on the contact line along the axis of the grinding wheel.

[0085] Step 6: Calculate the motion trajectory of the dressing roller according to the cross-sectional profile 300 of the combined grinding wheel shaft including the rough grinding wheel and the fine grinding wheel, and simultaneously dress the profiles of the rough grinding wheel 111 and the fine grinding wheel 110 on a gear forming grinding wheel gear grinding machine, and then grind the tooth surface of the internal gear 102 with the dressed combined grinding wheel;

[0086] First adjust the angle of the B axis of the internal gear forming grinding wheel gear grinding machine. For right-hand internal gears, Figure 3 As shown, the B axis rotates the internal gear helix angle 20 degrees in the positive direction, and the turntable 109 drives the combined grinding wheel to rotate 20 degrees. Then the rotation angle of the C axis, the movement of the Y axis and the movement of the Z axis are adjusted to make the fine grinding wheel 110 enter the tooth groove of the internal gear 102. At the same time, it is necessary to ensure that the center of the combined grinding wheel is lower than the upper end surface of the internal gear 102, and the two side surfaces of the fine grinding wheel 110 are in contact with the left and right tooth surfaces of the tooth groove. The tooth groove is set as the first tooth groove 200. In the CNC system, the rotation angle of the C axis, the value of the Y axis and the value of the Z axis at this position are the linkage initial positions of the axes of the CNC internal gear forming grinding wheel gear grinding machine; the movement relationship between the rotation of the C axis and the movement of the Z axis is as follows:

[0087]

[0088] Among them, Z0 is the moving distance of the Z axis, and C0 is the rotation angle of the C axis;

[0089] Under the premise that the linkage relationship between the C-axis and the Z-axis remains unchanged, the first slide 106 is fed in the positive direction. According to the grinding allowance and process requirements, after multiple shaping grinding movements, the X-axis is fed to the theoretical tooth depth position to complete the grinding of the first tooth groove 200, and the rough grinding of the second tooth groove 201 is also completed;

[0090] Then, the position of the X-axis is kept unchanged, and the third slide 108 moves along the negative Z direction of the third guide rail 107, while the movement relationship between the rotation of the C-axis and the movement of the Z-axis is kept unchanged, the combined grinding wheel withdraws from the tooth groove of the internal gear, and the linkage relationship between the C-axis and the Z-axis is released. The first turntable 101 drives the internal gear 102 to rotate around the positive direction of the C-axis by an angle of 2π / z, and the second tooth groove 201 of the internal gear is turned to the position of the first tooth groove 200, and then the linkage relationship between the C-axis and the Z-axis is maintained again, the second tooth groove 201 is finely ground, and the third tooth groove 202 is roughly ground; then the remaining tooth grooves of the internal gear 102 are formed and ground in turn until the grinding of all tooth surfaces of the internal gear 102 is completed.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear, characterized in that: The grinding wheel for grinding the internal gear is a combined grinding wheel including a fine grinding wheel and a rough grinding wheel; when the combined grinding wheel is used on the internal gear forming grinding wheel gear grinding machine to perform forming grinding on the tooth surface of the internal gear, the combined grinding wheel simultaneously performs rough grinding and fine grinding of different tooth grooves, including the following steps: Step 1: Establish the tooth surface equation and three-dimensional model of the first tooth groove of the internal gear; According to the rotation direction of the internal gear during the grinding process, the installation positions of the fine grinding wheel and the rough grinding wheel are determined; the gear coordinate system S0 (O0: x0, y0, z0), the fine grinding coordinate system S1 (O1: x1, y1, z1) and the rough grinding coordinate system S2 (O2: x2, y2, z2) are established; the directions of the x0, x1 and x2 coordinate axes are the same, and the axial directions of the x0 and x1 coordinate axes point to the first tooth groove of the internal gear, which is the tooth depth feed direction during grinding; the directions of the y1 and y2 coordinate axes are the same; the angle between the z0 coordinate axis and the y1 coordinate axis and the y2 coordinate axis is the internal gear helix angle; the origin O0 of the internal gear coordinate system S0 is at the center of the internal gear circle, and the distance between it and the coordinate origin O1 of the fine grinding wheel coordinate system S1 is the center distance a; in the internal gear coordinate system S1, the final tooth surface equation R1 and the tooth surface three-dimensional model D1 of the first tooth groove of the internal gear are established; the tooth groove adjacent to the first tooth groove of the internal gear is the second tooth groove; Step 2: The grinding of the first tooth groove by the fine grinding wheel and the grinding of the second tooth groove by the rough grinding wheel are considered as the initial grinding state; according to the total grinding amount of the internal gear, the grinding amount δ1 of the fine grinding and the grinding amount δ2 of the rough grinding are determined; Step 3, superimpose the tooth surface fine grinding amount δ1 with the final tooth surface three-dimensional model D1 of the internal gear, and establish the tooth surface equation R2 and the corresponding tooth surface three-dimensional model D2 of the second tooth groove of the internal gear corresponding to the rough grinding wheel; Step 4: According to the tooth surface equations R1 and R2 and the installation positions of the corresponding fine grinding wheel and rough grinding wheel, respectively solve the coordinate points of the contact lines L1 and L2 between the tooth surface at the first tooth groove and the tooth surface at the second tooth groove and the combined grinding wheel; Step 5: Convert the coordinate points of the contact lines L1 and L2 to the fine grinding wheel coordinate system S1 and the rough grinding wheel coordinate system S2 respectively, obtain the axial cross-section profiles of the rough grinding wheel and the fine grinding wheel, and smoothly connect the profiles of the rough grinding wheel and the fine grinding wheel to form a complete combined grinding profile; Step 6: The profiles of the rough grinding wheel and the fine grinding wheel are simultaneously trimmed according to the obtained combined grinding wheel profile, and then the tooth surface of the internal gear is ground with the trimmed combined grinding wheel.

2. The profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear according to claim 1, characterized in that: In step 1, the fine grinding wheel and the rough grinding wheel are coaxially installed along the grinding wheel axis direction, and the center distance a between the coordinate origin O0 of the internal gear coordinate system S0 and the origin O1 of the fine grinding wheel coordinate system S1 in the direction of the internal gear axis x0 is r0-r1, r0 is the pitch circle radius of the internal gear, and r1 is the pitch circle radius of the fine grinding wheel; The rotation direction of the internal gear is viewed from the positive direction of the z0 axis of the internal gear to the negative direction. When the internal gear rotates clockwise, the rough grinding wheel is installed along the negative direction of the z1 axis. If the internal gear rotates counterclockwise, the rough grinding wheel is installed along the positive direction of the z1 axis.

3. The profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear according to claim 1, characterized in that: In step 2, the installation distance d between the fine grinding wheel and the rough grinding wheel on the central axis is determined according to the relative positions of the first tooth groove and the second tooth groove and the rotation direction of the internal gear during the gear grinding process; In formula (1), β is the helix angle of the internal gear, r0 is the pitch radius of the internal gear, and z is the number of teeth of the internal gear.

4. The method for simultaneously grinding multiple tooth grooves of an internal gear according to claim 1, characterized in that: In step 1, the final tooth surface equation R1 of the first tooth groove is expressed as: In formula (2), the "+" in the "±" sign corresponds to the end face involute of the left tooth surface of the first tooth space, and the "-" in the "±" sign corresponds to the end face involute of the right tooth surface of the first tooth space. b is the base circle radius of the internal gear; μ is the involute angle; σ0 is the tooth gap half angle; matrix M g It is expressed as, In formula (3), the matrix M g The "+" in the "±" and The "-" in the symbol corresponds to the right-hand internal gear tooth surface; the matrix M g The "-" in the "±" and The "+" in the symbol corresponds to the left-handed internal gear tooth surface; P1 is the internal gear helical parameter, and θ is the rotation angle.

5. The profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear according to claim 4, characterized in that: In step 3, the tooth surface equation R2 at the second tooth groove is expressed as: In formula (4), r0 is the pitch circle radius of the internal gear, r b is the base circle radius of the internal gear, z is the number of teeth of the internal gear, M g is the matrix M g .

6. The profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear according to claim 5, characterized in that: In step 4, the calculated distribution of the contact lines L1 and L2 satisfies the tooth surface contact condition: zn x +an y cot∑+(a-x+P1cot∑)n z =0 (5); In formula (5), (x, y, z) are the coordinates of the tooth surface contact point obtained according to the tooth surface equation R1 of the first tooth groove of the internal gear or the tooth surface equation R2 of the second tooth groove, (n x , n y , n z ) are the three components of the tooth surface normal vector at the contact point of the internal gear tooth surface, P1 is the internal gear spiral parameter, Σ is the angle between the grinding wheel axis and the internal gear axis, z is the number of internal gear teeth; a=r0-r1, r0 is the pitch circle radius of the internal gear, and r1 is the pitch circle radius of the fine grinding wheel.

7. The profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear according to claim 1, characterized in that: In step 5, the transformation matrix from the internal gear coordinate system S0 to the grinding wheel coordinate system S1 is: The transformation matrix from the internal gear coordinate system S0 to the rough grinding wheel coordinate system S2 is: In the above formula, Σ is the angle between the grinding wheel axis and the internal gear axis, z is the number of teeth of the internal gear, β is the helix angle of the internal gear; a=r0-r1, r0 is the pitch circle radius of the internal gear, and r1 is the pitch circle radius of the fine grinding wheel.

8. The profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear according to claim 7, characterized in that: After the complete combined grinding wheel profile is obtained in step 5, coordinate transformation is performed. The coordinates of the tooth surface contact lines L1 and L2 calculated in step 4 are transformed into the fine grinding wheel coordinate system S1 and the rough grinding wheel coordinate system S2 to obtain the coordinates of the axial cross-section profiles of the fine grinding wheel and the rough grinding wheel.

9. The profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear according to claim 1, characterized in that: In step six, when grinding the tooth surface of the internal gear with the dressed combined grinding wheel, first adjust the relative position of the fine grinding wheel and the first tooth groove of the internal gear, starting from the initial contact position of the fine grinding wheel and the rough grinding wheel with the tooth surface of the internal gear, according to the total grinding allowance, feed multiple times along the x0 coordinate axis direction of the internal gear, and gradually feed to the final grinding position of the internal gear, and then keep the feed position of the combined grinding wheel unchanged, and grind the tooth surfaces corresponding to the remaining tooth grooves of the internal gear according to the motion relationship of the formed grinding until the grinding of all the tooth surfaces of the internal gear is completed.

10. The profile grinding method for simultaneously grinding multiple tooth grooves of an internal gear according to claim 1, characterized in that: The combined grinding wheel comprises one or more rough grinding gears and fine grinding gears; according to processing requirements, the grinding wheel materials of the rough grinding wheel and the fine grinding wheel are the same or different, and the grinding wheel grain sizes of the rough grinding wheel and the fine grinding wheel are different.

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