Workpiece grinding method and grinding system

Abstract

The invention provides a grinding method and a grinding system for a workpiece. A method for grinding a workpiece (12) includes: a first grinding step for grinding a workpiece tooth surface (62) by a grinding tooth surface (66) by causing a gear-shaped workpiece to mesh with a grinding tool (14) and rotating the gear-shaped workpiece, a first correction information generation step for generating first correction information, and a second grinding step for generating second correction information by causing the gear-shaped workpiece to mesh with the grinding tool (14) and rotating the gear-shaped workpiece; a first correction information generation step in which first correction information (104) is generated by inverting the first bounce waveform (102); in the second grinding step, the tooth surface of the workpiece is ground by the grinding tooth surface by changing the rotation speed of the workpiece or the grinding tool on the basis of the first correction information in a state in which the workpiece and the grinding tool are engaged and rotated. Therefore, the grinding method and the grinding system for the workpiece can be better provided.

Description

Technical Field

[0001] The invention relates to a workpiece grinding method and a grinding system. Background Art

[0002] Japanese Patent Application No. 5467833 discloses a workpiece grinding method in which a gear-shaped workpiece is meshed with a grinding tool and rotated, and the helical grinding tooth surfaces of the grinding tool are used to grind the workpiece tooth surfaces. Summary of the Invention

[0003] A better workpiece grinding method and grinding system are desired.

[0004] The purpose of the present invention is to solve the above technical problems.

[0005] The first embodiment of the present invention is a method for grinding a workpiece, comprising a first grinding step, a first correction information generating step, and a second grinding step, wherein, in the first grinding step, a gear-shaped workpiece is meshed with a grinding tool and rotated, so that the workpiece tooth surface of the workpiece is ground by the spiral grinding tooth surface of the grinding tool; in the first correction information generating step, first correction information is generated by inverting a first runout waveform, wherein the first runout waveform represents the relationship between the runout amount of the workpiece tooth surface relative to the grinding tooth surface in the first grinding step and the rotational phase of the workpiece; in the second grinding step, while the workpiece is meshed with the grinding tool and rotated, the rotation speed of the workpiece or the grinding tool is changed according to the first correction information, thereby grinding the workpiece tooth surface by the grinding tooth surface.

[0006] A second embodiment of the present invention is a grinding system comprising a grinding control unit and a correction information generating unit, wherein the grinding control unit performs a first grinding step of grinding a workpiece tooth surface of the workpiece by meshing and rotating a gear-shaped workpiece with a grinding tool; the correction information generating unit generates first correction information by inverting a first runout waveform, wherein the first runout waveform represents the relationship between the runout amount of the workpiece tooth surface relative to the grinding tooth surface in the first grinding step and the rotational phase of the workpiece; the grinding control unit further performs a second grinding step, in which, while the workpiece is meshed and rotated with the grinding tool, the rotation speed of the workpiece or the grinding tool is changed according to the first correction information, thereby grinding the workpiece tooth surface by the grinding tooth surface.

[0007] According to the present invention, a more favorable workpiece grinding method and grinding system can be provided.

[0008] The above-mentioned objects, features and advantages will be easily understood through the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view of a grinding system according to an embodiment.

[0010] Figure 2 It is the control block diagram of the grinding system.

[0011] Figure 3 This is a flowchart showing an example of a method for grinding a workpiece.

[0012] Figure 4 This is an explanatory diagram of the first correction information generating step.

[0013] Figure 5 It is an explanatory diagram of the second correction information generating step.

[0014] Figure 6 This is a graph showing the runout waveform in the third grinding step. DETAILED DESCRIPTION

[0015] Gear-shaped workpieces are heat treated before grinding. In this case, the workpiece may deform into an elliptical shape when viewed from the axis of rotation due to thermal deformation. This can prevent high-precision grinding of the workpiece tooth surfaces. The present invention provides a workpiece grinding method and system capable of high-precision grinding of workpiece tooth surfaces.

[0016] Figure 1 : is a perspective view of the grinding system 10 involved in the embodiment. Figure 1 As shown, the grinding system 10 is a system for grinding a gear-shaped workpiece 12 using a grinding tool 14. The grinding system 10 includes a bed 16, a gear support mechanism 18, a gear rotation mechanism 20, a tool support mechanism 22, a tool rotation mechanism 24, and a control device 26.

[0017] The base 16 is placed on a horizontal surface in a factory, etc. The gear support mechanism 18 is arranged on the flat upper surface of the base 16. The gear support mechanism 18 includes a feed table 28, a feed motor 30, a traverse table 32, and a traverse motor 34.

[0018] The feed table 28 moves in the direction A relative to the base 16. The direction A is a horizontal direction perpendicular to the height direction of the base 16. The feed table 28 is connected to the feed motor 30 via a ball screw shaft 36. The feed motor 30 moves the feed table 28 in the direction A by rotating the ball screw shaft 36.

[0019] The traverse table 32 is arranged on the upper surface of the feed table 28. The traverse table 32 moves relative to the feed table 28 in the B direction. The B direction is perpendicular to the height direction of the base 16 and the A direction. The traverse table 32 is connected to the traverse motor 34 via a ball screw shaft (not shown). The traverse motor 34 rotates the ball screw shaft to move the traverse table 32 in the B direction.

[0020] The gear rotating mechanism 20 is arranged on the upper surface of the traverse table 32. The gear rotating mechanism 20 includes a gear mounting shaft 38 and a first motor 40. The gear mounting shaft 38 extends in the direction B. The workpiece 12 is detachably mounted on the gear mounting shaft 38. The first motor 40 rotates the gear mounting shaft 38.

[0021] The tool support mechanism 22 includes a column 42, a rotary table 44, a shift table 46, and a shift motor 48. The column 42 is disposed on the upper surface of the base 16 so as to face the gear support mechanism 18. The column 42 extends upward from the base 16. The rotary table 44 is mounted on the surface of the column 42 that faces the gear support mechanism 18.

[0022] The rotary table 44 extends in one direction. A rotary motor (not shown) rotates the rotary table 44 in the direction C relative to the column 42. A displacement table 46 is provided on the surface of the rotary table 44 facing the gear support mechanism 18. The displacement table 46 is connected to the displacement motor 48 via a ball screw shaft 50. The displacement motor 48 is mounted on the rotary table 44. The displacement motor 48 moves the displacement table 46 in the direction D relative to the rotary table 44.

[0023] The tool rotation mechanism 24 includes a base 54, a tool mounting shaft 56, and a second motor 58. The base 54 is mounted on the surface of the displacement table 46 facing the gear support mechanism 18. The base 54 extends along the direction in which the rotation table 44 extends. The tool mounting shaft 56 penetrates the base 54 along the direction in which the base 54 extends. The grinding tool 14 is detachably mounted on the tool mounting shaft 56. The second motor 58 rotates the tool mounting shaft 56.

[0024] like Figure 2 As shown, the workpiece 12 is mounted on the gear mounting shaft 38. The workpiece 12 can rotate in the R1 direction and the R2 direction by the driving force of the first motor 40. The workpiece 12 has a plurality of teeth 60. Each of the plurality of teeth 60 has a workpiece tooth surface 62. The workpiece tooth surface 62 includes a left workpiece tooth surface 62a and a right workpiece tooth surface 62b.

[0025] The grinding tool 14 is mounted on the tool mounting shaft 56. The grinding tool 14 can rotate in the R3 direction and the R4 direction by the driving force of the second motor 58. The grinding tool 14 is a tool for grinding the workpiece 12. The grinding tool 14 has spiral grinding teeth 64. The grinding teeth 64 are formed with grinding tooth surfaces 66. The grinding tooth surfaces 66 include a first grinding tooth surface 66a and a second grinding tooth surface 66b. A single layer of CBN (cubic boron nitride) abrasive grains is electrodeposited on the grinding tooth surfaces 66, for example, by nickel plating.

[0026] When the workpiece 12 is ground by the grinding tool 14, the workpiece 12 is meshed with the grinding tool 14. When the workpiece 12 and the grinding tool 14 are meshed, the left workpiece tooth surface 62a faces the first grinding tooth surface 66a, and the right workpiece tooth surface 62b faces the second grinding tooth surface 66b. When the workpiece 12 and the grinding tool 14 are meshed, for example, by rotating the workpiece 12 in the R1 direction and the grinding tool 14 in the R3 direction, the left workpiece tooth surface 62a can be ground by the first grinding tooth surface 66a, and the right workpiece tooth surface 62b can be ground by the second grinding tooth surface 66b. In addition, when the workpiece 12 is engaged with the grinding tool 14, for example, by rotating the workpiece 12 in the R2 direction and rotating the grinding tool 14 in the R4 direction, the left workpiece tooth surface 62a can be ground by the first grinding tooth surface 66a and the right workpiece tooth surface 62b can be ground by the second grinding tooth surface 66b.

[0027] The grinding system 10 further includes a first encoder 68 and a second encoder 70. The first encoder 68 is provided on the first motor 40. The first encoder 68 outputs information (e.g., a pulse signal) related to the rotation phase (rotation speed, rotation angle, rotation position, rotation amount) of the workpiece 12 to the control device 26.

[0028] The second encoder 70 is provided on the second motor 58 . The second encoder 70 outputs information (eg, a pulse signal) on the rotation phase (rotation speed, rotation angle, rotation position, rotation amount) of the grinding tool 14 to the control device 26 .

[0029] The control device 26 includes a first servo amplifier 74, a second servo amplifier 76, and a control main unit 78. The first servo amplifier 74 controls the rotation of the first motor 40 based on a signal output from the control main unit 78. The second servo amplifier 76 controls the rotation of the second motor 58 based on a signal output from the control main unit 78.

[0030] The control unit 78 includes a computing unit 80, a storage unit 82, an operating unit 84, and a display unit 86. The computing unit 80 is composed of a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). In other words, the computing unit 80 is composed of processing circuitry.

[0031] The computing unit 80 includes a control unit 88, a grinding control unit 90, an information acquisition unit 92, and a correction information generation unit 94. The controller 88 controls the feed motor 30, the traverse motor 34, the rotation motor (not shown), and the displacement motor 48. The grinding control unit 90 controls the rotation of the workpiece 12 via the first servo amplifier 74. Furthermore, the grinding control unit 90 controls the rotation of the grinding tool 14 via the second servo amplifier 76. The information acquisition unit 92 acquires information output from the first encoder 68 and information output from the second encoder 70. The correction information generation unit 94 generates first correction information 104 and second correction information 110, which will be described later.

[0032] The control unit 88, grinding control unit 90, information acquisition unit 92, and correction information generation unit 94 can be implemented by the computing unit 80 executing a program stored in the storage unit 82. Furthermore, at least a portion of the control unit 88, grinding control unit 90, information acquisition unit 92, and correction information generation unit 94 can be implemented using an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). Furthermore, at least a portion of the control unit 88, grinding control unit 90, information acquisition unit 92, and correction information generation unit 94 can be implemented using electronic circuits including discrete components.

[0033] The storage unit 82 is composed of a volatile memory (not shown) and a non-volatile memory (not shown). Examples of volatile memory include RAM (Random Access Memory). Volatile memory is used as working memory for the processor, temporarily storing data required for processing or calculations. Examples of non-volatile memory include ROM (Read Only Memory) and flash memory. Non-volatile memory is used as storage memory, storing programs, tables, maps, etc. At least a portion of the storage unit 82 may be provided in a processor, integrated circuit, or the like as described above.

[0034] The operating unit 84 is used by the user to operate the control device 26. Furthermore, the operating unit 84 may include a keyboard, a mouse, or the like. The display unit 86 includes a display element (not shown). Examples of such display elements include liquid crystal display elements and organic electroluminescent display elements. Alternatively, the operating unit 84 and the display unit 86 may be configured using a touch screen (not shown) having such a display element.

[0035] Next, an example of a method for grinding the workpiece 12 will be described. Figure 3 1 is a flowchart showing an example of a method for grinding a workpiece 12. In addition, the workpiece 12 is subjected to heat treatment before grinding. In this case, when viewed from the direction of the rotation axis of the workpiece 12, the workpiece 12 may be deformed into an elliptical shape due to thermal deformation.

[0036] In step S1, the workpiece 12 is mounted on the gear mounting shaft 38, and the grinding tool 14 is mounted on the tool mounting shaft 56. Thereafter, the process proceeds to step S2.

[0037] In step S2, the workpiece 12 is meshed with the grinding tool 14. Specifically, the control unit 88 controls the feed motor 30, the traverse motor 34, the rotation motor (not shown), and the displacement motor 48 to mesh the workpiece 12 with the grinding tool 14. Thereafter, the process proceeds to step S3.

[0038] In step S3, the first grinding step is performed. In the first grinding step, the workpiece tooth surface 62 is roughly ground (first rough grinding). The grinding control unit 90 rotates the workpiece 12 via the first servo amplifier 74 and rotates the grinding tool 14 via the second servo amplifier 76. The grinding control unit 90 causes the workpiece 12 and the grinding tool 14 to rotate synchronously. In other words, the grinding control unit 90 performs feedback control on the first servo amplifier 74 and the second servo amplifier 76 based on the information output from the first encoder 68 and the information output from the second encoder 70, so that the workpiece 12 and the grinding tool 14 rotate while maintaining the meshing state.

[0039] In the first grinding step, the entire circumference of the workpiece 12 (all workpiece tooth surfaces 62) is ground. Furthermore, if the workpiece 12 is deformed due to thermal deformation, the workpiece tooth surface 62 may run out relative to the ground tooth surface 66 during the first grinding step. After this, the process proceeds to step S4.

[0040] In step S4, a first correction information generating step is performed. Figure 4 This is an explanatory diagram of the first correction information generation step. Figure 4In the figure, the horizontal axis represents the rotational phase of the workpiece 12, and the vertical axis represents the rotational phase difference of the workpiece 12. In the first correction information generating step, the difference (rotational phase difference) between the command value of the rotational phase of the workpiece 12 and the detected value of the rotational phase of the workpiece 12 in the first grinding step is obtained as the runout amount of the workpiece tooth surface 62 relative to the ground tooth surface 66. The rotational phase difference of the workpiece 12 represents the synchronization error of the rotation of the workpiece 12.

[0041] like Figure 4 As shown, in the first correction information generating step, the correction information generating unit 94 generates the first correction information 102 by performing a sinusoidal approximation on the runout waveform 100 representing the relationship between the runout amount of the workpiece tooth surface 62 relative to the grinding tooth surface 66 in the first grinding step and the rotation phase of the workpiece 12. That is, the first runout waveform 102 represents the change in the runout amount of the workpiece tooth surface 62 over the entire circumference of the workpiece 12 in the first grinding step. In other words, the first runout waveform 102 represents the grinding error of the first grinding step. In addition, in the first correction information generating step, the correction information generating unit 94 generates the first correction information 104 by inverting the first runout waveform 102. The first correction information 104 is a waveform representing the relationship between the runout amount of the workpiece tooth surface 62 relative to the grinding tooth surface 66 in the first grinding step and the rotation phase of the workpiece 12. Figure 4 The information of the waveform obtained by inverting the first jitter waveform 102 in the direction of the vertical axis (the amplitude direction of the first jitter waveform 102). After this, the process moves to step S5.

[0042] In step S5, the second grinding step is performed. In the second grinding step, the workpiece tooth surface 62 is roughly ground (second rough grinding). In the second grinding step, the grinding control unit 90 changes the rotation speed of the workpiece 12 according to the first correction information 104 while the workpiece 12 and the grinding tool 14 are meshed and rotated, thereby grinding the workpiece tooth surface 62 through the grinding tooth surface 66. In other words, the grinding control unit 90 grinds the workpiece tooth surface 62 through the grinding tooth surface 66 by outputting a command signal generated based on the synchronous rotation signal of the workpiece 12 and the first correction information 104 to the first servo amplifier 74, and outputting a synchronous rotation signal of the grinding tool 14 to the second servo amplifier 76. That is, in the second grinding step, the grinding control unit 90 performs feedback control on the rotation speed of the workpiece 12 so as to reduce the grinding error generated in the first grinding step (correction contact component).

[0043] Thus, in the second grinding step, the grinding error generated in the first grinding step can be reduced. Furthermore, in the second grinding step, while the workpiece 12 and the grinding tool 14 are meshed and rotated, the rotational speed of the grinding tool 14 can be changed based on the first correction information 104, thereby grinding the workpiece tooth surface 62 by grinding the tooth surface 66. After this, the process proceeds to step S6.

[0044] In step S6, a second correction information generating step is performed. Figure 5 This is an explanatory diagram of the second correction information generation step. Figure 5 , the horizontal axis represents the rotation phase of the workpiece 12 , and the vertical axis represents the rotation phase difference of the workpiece 12 .

[0045] like Figure 5 As shown, in the second correction information generating step, the correction information generating unit 94 generates a second correction information 108 by performing a sinusoidal approximation on the correction waveform 106 representing the relationship between the runout amount of the workpiece tooth surface 62 relative to the grinding tooth surface 66 in the second grinding step and the rotation phase of the workpiece 12. That is, the second runout waveform 108 represents the change in the runout amount of the workpiece tooth surface 62 over the entire circumference of the workpiece 12 in the second grinding step. In other words, the second runout waveform 108 represents the grinding error of the second grinding step. In addition, in the second correction information generating step, the correction information generating unit 94 generates the second correction information 110 by inverting the second runout waveform 108. The second correction information 110 is a waveform representing the change in the runout amount of the workpiece tooth surface 62 over the entire circumference of the workpiece 12 in the second grinding step. Figure 5 The information of the waveform obtained by inverting the second jitter waveform 108 in the direction of the vertical axis (the amplitude direction of the second jitter waveform 108). Thereafter, the process moves to step S7.

[0046] In step S7, the third grinding step is performed. In the third grinding step, the workpiece tooth surface 62 is finish-ground. In the third grinding step, the grinding control unit 90 changes the rotation speed of the workpiece 12 according to the second correction information 110 while the workpiece 12 and the grinding tool 14 are meshed and rotated, thereby grinding the workpiece tooth surface 62 via the grinding tooth surface 66. In other words, the grinding control unit 90 outputs a command signal generated based on the synchronous rotation signal of the workpiece 12 and the second correction information 110 to the first servo amplifier 74, and outputs a synchronous rotation signal of the grinding tool 14 to the second servo amplifier 76, thereby grinding the workpiece tooth surface 62 via the grinding tooth surface 66. That is, in the third grinding step, the grinding control unit 90 performs feedback control on the rotation speed of the workpiece 12 so as to reduce the grinding error generated in the second grinding step (correction contact component).

[0047] Figure 6 1 is a graph showing the runout waveform 112 of the third grinding step. Figure 6 As shown, in the third grinding step, since the grinding error generated in the second grinding step can be reduced, the workpiece tooth surface 62 can be ground with higher precision. In addition, in the third grinding step, the rotation speed of the grinding tool 14 can be changed according to the second correction information 110 while the workpiece 12 and the grinding tool 14 are meshed and rotated, thereby grinding the workpiece tooth surface 62 by grinding the tooth surface 66. Thereafter, Figure 3 The processing is completed.

[0048] According to this embodiment, the second grinding step is performed based on first correction information 104 generated by inverting first runout waveform 102, which represents the relationship between the runout amount of workpiece tooth surface 62 and the rotational phase of workpiece 12 during the first grinding step. This reduces the grinding error generated during the first grinding step during the second grinding step. Consequently, workpiece tooth surface 62 can be ground with high precision. Consequently, a more advanced method for grinding workpiece 12 and grinding system 10 can be provided.

[0049] The following supplementary notes are also disclosed regarding the above-mentioned embodiment.

[0050] (Note 1) The workpiece grinding method of the present invention includes a first grinding step, a first correction information generating step, and a second grinding step, wherein, in the first grinding step, a gear-shaped workpiece (12) is meshed with a grinding tool (14) and rotated, so that a workpiece tooth surface (62) of the workpiece is ground by the spiral grinding tooth surface (66) of the grinding tool; in the first correction information generating step, first correction information (104) is generated by inverting a first runout waveform (102), wherein the first runout waveform represents the relationship between the runout amount of the workpiece tooth surface relative to the grinding tooth surface in the first grinding step and the rotation phase of the workpiece; in the second grinding step, while the workpiece is meshed with the grinding tool and rotated, the rotation speed of the workpiece or the grinding tool is changed according to the first correction information, thereby grinding the workpiece tooth surface by the grinding tooth surface.

[0051] With this configuration, the second grinding step is performed based on the first correction information generated by inverting the first runout waveform representing the relationship between the contact amount of the workpiece tooth surface and the rotational phase of the workpiece during the first grinding step. Consequently, the grinding error generated during the first grinding step can be reduced during the second grinding step. Consequently, the workpiece tooth surface can be ground with high precision. Consequently, a more advanced workpiece grinding method can be provided.

[0052] (Note 2) In the workpiece grinding method described in Supplement 1, in the first correction information generating step, a difference between a command value of the rotational phase of the workpiece in the first grinding step and a detected value of the rotational phase of the workpiece may be obtained as the runout amount.

[0053] According to this configuration, the first correction information can be easily generated.

[0054] (Note 3) The method for grinding a workpiece according to Note 1 or 2 may include a second correction information generating step and a third grinding step, wherein, in the second correction information generating step, second correction information (110) is generated by inverting a second jitter waveform (108), wherein the second jitter waveform represents the relationship between the jitter amount of the workpiece tooth surface relative to the grinding tooth surface in the second grinding step and the rotational phase of the workpiece; and in the third grinding step, while the workpiece and the grinding tool are meshed and rotated, the rotational speed of the workpiece or the grinding tool is changed according to the second correction information, thereby grinding the workpiece tooth surface through the grinding tooth surface.

[0055] With this configuration, the third grinding step is performed based on the second correction information generated by inverting the second runout waveform representing the relationship between the runout amount of the workpiece tooth surface and the rotational phase of the workpiece during the second grinding step. This reduces the grinding error generated during the second grinding step during the third grinding step. Consequently, the tooth surface can be ground with higher precision.

[0056] (Note 4) The grinding system (10) of the present invention includes a grinding control unit (90) and a correction information generating unit (94), wherein the grinding control unit performs a first grinding step of grinding the workpiece tooth surface of the workpiece by the spiral grinding tooth surface of the grinding tool by meshing and rotating the gear-shaped workpiece with the grinding tool; the correction information generating unit generates first correction information by inverting a first runout waveform, wherein the first runout waveform represents the relationship between the runout amount of the workpiece tooth surface relative to the grinding tooth surface in the first grinding step and the rotational phase of the workpiece; and the grinding control unit further performs a second grinding step, in which, while the workpiece is meshed and rotated with the grinding tool, the rotation speed of the workpiece or the grinding tool is changed according to the first correction information, thereby grinding the workpiece tooth surface by the grinding tooth surface.

[0057] According to this structure, the same effect as that of Supplementary Note 1 can be achieved. Therefore, a better grinding system can be provided.

[0058] (Note 5) In the grinding system according to Supplementary Note 4, the correction information generating unit may acquire, as the runout amount, a difference between a command value of the rotational phase of the workpiece and a detected value of the rotational phase of the workpiece in the first grinding step.

[0059] According to this structure, the same effect as Supplementary Note 2 can be achieved.

[0060] (Note 6) In the grinding system described in Appendix 4 or 5, the correction information generating unit may generate second correction information by inverting a second runout waveform, wherein the second runout waveform represents the relationship between the runout amount of the workpiece tooth surface relative to the grinding tooth surface in the second grinding step and the rotational phase of the workpiece, and the grinding control unit may further perform a third grinding step, in which the rotational speed of the workpiece or the grinding tool is changed according to the second correction information while the workpiece and the grinding tool are meshed and rotated, thereby grinding the workpiece tooth surface by the grinding tooth surface.

[0061] According to this structure, the same effect as that of Supplementary Note 3 can be achieved.

[0062] The present invention has been described in detail, but the present invention is not limited to the above-mentioned embodiments. These embodiments can be supplemented, replaced, changed, partially deleted, etc. in a manner that does not deviate from the scope of the present invention or in a manner that does not deviate from the scope of the present invention derived from the contents recorded in the technical solution and its equivalents. In addition, these embodiments can also be implemented in combination. For example, in the above-mentioned embodiment, the order of each action and the order of each processing are shown as an example, but are not limited to this. In addition, the same applies when numerical values ​​or mathematical formulas are used in the description of the above-mentioned embodiment.

Claims

1. A method for grinding a workpiece, characterized in that: The method comprises a first grinding step, a first correction information generating step and a second grinding step, wherein: In the first grinding step, the gear-shaped workpiece is meshed with the grinding tool and rotated, thereby grinding the workpiece tooth surface of the workpiece by the spiral grinding tooth surface of the grinding tool; In the first correction information generating step, first correction information is generated by inverting a first runout waveform, wherein the first runout waveform represents a relationship between a runout amount of the workpiece tooth surface relative to the ground tooth surface in the first grinding step and a rotational phase of the workpiece; In the second grinding step, while the workpiece and the grinding tool are meshed and rotated, the rotation speed of the workpiece or the grinding tool is changed according to the first correction information, thereby grinding the workpiece tooth surface by the grinding tooth surface.

2. The workpiece grinding method according to claim 1, wherein: In the first correction information generating step, a difference between a command value of the rotational phase of the workpiece and a detected value of the rotational phase of the workpiece in the first grinding step is acquired as the runout amount.

3. The workpiece grinding method according to claim 1 or 2, characterized in that: The method comprises a second correction information generating step and a third grinding step, wherein: In the second correction information generating step, second correction information is generated by inverting a second runout waveform, wherein the second runout waveform represents a relationship between a runout amount of the workpiece tooth surface relative to the ground tooth surface in the second grinding step and a rotational phase of the workpiece; In the third grinding step, while the workpiece and the grinding tool are meshed and rotated, the rotation speed of the workpiece or the grinding tool is changed according to the second correction information, thereby grinding the workpiece tooth surface by the grinding tooth surface.

4. A grinding system, characterized in that: It includes a grinding control unit and a correction information generating unit, wherein: The grinding control unit performs a first grinding step of grinding a workpiece tooth surface of the workpiece with a spiral grinding tooth surface of the grinding tool by meshing and rotating the gear-shaped workpiece with the grinding tool; The correction information generating unit generates first correction information by inverting a first runout waveform indicating a relationship between a runout amount of the workpiece tooth surface relative to the ground tooth surface in the first grinding step and a rotational phase of the workpiece. The grinding control unit also performs a second grinding step, in which, while the workpiece and the grinding tool are meshed and rotated, the rotation speed of the workpiece or the grinding tool is changed according to the first correction information, thereby grinding the workpiece tooth surface through the grinding tooth surface.

5. The grinding system according to claim 4, characterized in that The correction information generating unit acquires a difference between a command value of the rotational phase of the workpiece and a detected value of the rotational phase of the workpiece in the first grinding step as the runout amount.

6. The grinding system according to claim 4 or 5, characterized in that The correction information generating unit generates second correction information by inverting a second runout waveform indicating a relationship between a runout amount of the workpiece tooth surface relative to the ground tooth surface in the second grinding step and a rotational phase of the workpiece. The grinding control unit further performs a third grinding step in which, while the workpiece and the grinding tool are meshed and rotated, the rotation speed of the workpiece or the grinding tool is changed according to the second correction information, thereby grinding the workpiece tooth surface by the grinding tooth surface.

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