A grinding wheel dressing method for machining a cycloidal gear using a worm grinding wheel grinding machine

Abstract

This invention discloses a grinding wheel dressing method for machining cycloidal gears using a worm gear grinding machine. The key feature is the use of a worm gear grinding machine that integrates cycloidal gear machining and grinding wheel dressing functions to achieve rapid and precise grinding wheel dressing. The worm gear grinding machine, with an adjustable central axis swivel angle for the dresser, increases the dresser's freedom of movement during dressing, reducing the impact of changes in the grinding wheel tooth profile, controlling errors during dressing, and improving machine tool stability. A contact vibration sensor is installed on the grinding wheel; by sensing vibration data, the machine tool automatically adjusts the dresser's alignment, simplifying manual operation, improving dressing accuracy, and saving time. After the initial alignment, the dresser does not need to be aligned again, improving dressing efficiency. By differentiating the two-stage machining process of dressing the grinding wheel, the roughing stage quickly removes excess material from the grinding wheel while the finishing stage maintains a good surface morphology.

Description

Technical Field

[0001] This invention discloses a grinding wheel dressing method for machining cycloidal gears using a worm gear grinding machine. The key feature is that the worm gear grinding machine allows adjustment of the swing angle of the dresser's central axis, reducing the impact of repeated dressing on the grinding wheel's outer diameter and the grinding wheel tooth surface deviating from the theoretical tooth surface conjugate with the cycloidal gear tooth surface. It also makes the errors generated during grinding wheel dressing controllable, thereby improving the meshing characteristics when machining cycloidal gears. Furthermore, it utilizes a tool setting method incorporating a contact vibration sensor to improve the speed and accuracy of tool setting in the worm gear grinding machine. The grinding wheel is dressed in stages, with roughing and finishing processes ensuring the accuracy of the grinding wheel tooth profile. This invention belongs to the field of grinding wheel dressing for worm gear grinding machines within the precision manufacturing industry. Background Technology

[0002] Cycloidal gears, characterized by high transmission precision, high transmission efficiency, large reduction ratio, compact structure, and long service life, are crucial components in the transmission systems of robots and other electromechanical systems. Their machining has always been a key research focus. With rapid industrial development, various industries have placed increasingly urgent demands on the precision and machining efficiency of cycloidal gears, making gear grinding the only necessary method. For cycloidal gears performing precision transmission functions, generating grinding is a high-performance precision machining method with excellent cost-effectiveness, significantly improving production efficiency by forming complex surfaces in a single operation.

[0003] However, in the generating gear grinding process, after the grinding wheel and cycloidal gear surfaces interact for a period of time, the abrasive grains on the grinding wheel lose their sharp edges and gradually become dull. Furthermore, grinding debris remains in the irregular pores on the grinding wheel surface, affecting the serrations and reducing the overall cutting force. Consequently, the grinding effect on the workpiece is also affected, leading to a series of problems such as slippage, machining noise, scratches, and incomplete machining when grinding cycloidal gears. To ensure the sharpness and shape accuracy of the grinding wheel surface, it is necessary to dress the grinding wheel regularly. Efficient and high-precision dressing of the grinding wheel can ensure the accuracy of the machined parts and improve machine tool production efficiency. Grinding wheel dressing methods on worm gear grinding machines are an important area of ​​focus for scholars and manufacturers both domestically and internationally. Current grinding wheel dressing methods include turning dressing, rolling dressing, diamond wheel dressing, laser dressing, ultrasonic vibration dressing, and electrical discharge dressing. Turning dressing uses a diamond pen as a cutting tool to turn the grinding wheel. However, because the diamond pen tip itself has no sharpening function and the contact area with the grinding wheel is small, the diamond pen tip wears quickly, reducing processing efficiency. Rolling dressing uses a carbide disc and a set of rollers made of corrugated white cast iron discs or grooved hardened steel sheets to roll and press against the grinding wheel for dressing. This method is suitable for dressing rough grinding wheels but not for high-precision grinding wheels. Diamond roller dressing uses the relative motion between the diamond roller and the grinding wheel to remove debris and residual bonding agent from the grinding wheel surface. It has a shorter dressing time and is suitable for dressing grinding wheels on worm gear grinding machines. In addition, laser dressing, ultrasonic vibration dressing, and electrical discharge dressing belong to the field of special dressing. Their application in small and medium-sized factories is costly and requires stringent installation conditions, making widespread and effective use currently difficult.

[0004] For conventional worm gear grinding machines, dressing the grinding wheel inevitably reduces its outer diameter, leading to an increase in the lead angle of the grinding wheel tip. This causes the grinding wheel tooth profile to gradually change, deviating from the theoretically conjugate tooth profile designed based on the workpiece's tooth profile, thus reducing the machining accuracy of the workpiece. Solving this problem is a crucial research direction in the industry.

[0005] In summary, for the grinding wheel dressing process in cycloidal gear machining, the use of a diamond roller dresser can meet the dressing requirements. Therefore, this invention discloses a grinding wheel dressing method for cycloidal gear machining on a worm gear grinding machine, so as to achieve the purpose of dressing the grinding wheel with high efficiency and high precision. Summary of the Invention

[0006] To address the problems currently encountered in worm gear grinding machines, such as the grinding wheel tooth profile deviating from the theoretical tooth profile conjugate with the cycloidal gear tooth surface due to multiple grinding wheel dressings, the inability to control grinding wheel dressing errors, the low level of machine tool control intelligence, and inaccurate tool setting during dressing, this invention discloses a grinding wheel dressing method for machining cycloidal gears using a worm gear grinding machine. The technical solution adopted is as follows:

[0007] A method for dressing grinding wheels for machining cycloidal gears using a worm gear grinding machine, wherein the structure of the worm gear grinding machine includes:

[0008] Machine tool base, CRT large turntable, workpiece turntable, workpiece, dresser mounting bracket, grinding wheel mounting bracket, Y-rail, X-rail, Z-rail, grinding wheel, dresser, dresser rotating motor, workpiece clamping bracket, W-rail, grinding wheel wire start end face, grinding wheel wire end end face, grinding wheel fixing screw, contact vibration sensor, dresser fixing screw, dresser mounting expansion shaft.

[0009] In the improved design, the dresser mounting bracket is mounted on the CRT turntable and can rotate with the axis C2 of the dresser mounting bracket to adjust the swing angle of the dresser's central axis B2. This reduces the impact of the grinding wheel's outer diameter reduction and the grinding wheel tooth profile deviating from the theoretical tooth surface conjugate with the cycloidal gear tooth profile caused by multiple dressings. It also makes the error generated during grinding wheel dressing controllable, thereby improving the meshing characteristics when grinding wheels are used to process cycloidal gears and enhancing the stability of machine tool processing.

[0010] In the improved design, a contact vibration sensor mounted on the grinding wheel can sense and acquire vibration data. By analyzing the amplitude and frequency of the vibrations, the centering position of the dresser is determined, guiding it to the designated starting point. This method eliminates the need for manual adjustments based on worker judgment, simplifying manual operation, saving labor costs, improving dressing accuracy, and reducing working time.

[0011] In the improved solution, the indexing rotation of the grinding wheel is calculated and controlled to accurately locate the starting position of the second thread end during the machining process. This eliminates the need to rely on vibration sensors to determine and guide alignment, reducing dressing preparation time and effectively improving machining speed.

[0012] The improved solution distinguishes between two machining stages during the dressing of the grinding wheel. The difference between these two stages lies in the amount of grinding and the movement of the grinding wheel. Roughing can quickly remove excess material, while finishing can maintain a good surface morphology. Through these two stages of machining, errors caused by insufficient centering and indexing accuracy are reduced, resulting in a well-finished grinding wheel surface with unchanged shape and contour, thus ensuring the surface accuracy of the cycloidal gear workpiece.

[0013] The technical effects achieved by this invention are as follows:

[0014] 1. Increase the freedom of movement of the dresser when dressing grinding wheels on a machine tool: Make the angle of the dresser mounting bracket adjustable, so that the swing angle of the dresser's central axis changes. This reduces the impact of the grinding wheel's outer diameter reduction and the theoretical tooth surface of the grinding wheel tooth profile being decoupled from the cycloidal gear tooth profile caused by multiple dressings. It also makes the errors generated during grinding wheel dressing controllable, thereby improving the meshing characteristics when grinding wheels are used to process cycloidal gears and increasing the stability of machine tool processing.

[0015] 2. By sensing the contact state between the grinding wheel and the dresser through a contact vibration sensor installed on the grinding wheel, the machine tool can autonomously adjust the tool setting and machining during grinding wheel dressing, thereby improving the machine tool's autonomy, enhancing its intelligence, and simplifying manual operation.

[0016] 3. The entire dressing process of the grinding wheel can be completed with a single tool setting before machining, eliminating the need to rely on vibration sensors to determine and guide centering, thus reducing dressing preparation time and effectively improving machining efficiency.

[0017] 4. Differentiate between two machining stages in the dressing process of the grinding wheel. Roughing can quickly remove excess material, while finishing can maintain a good surface morphology. Through two levels of machining, the error caused by insufficient centering and indexing accuracy is reduced, and the surface accuracy of the dressed grinding wheel can be achieved with good surface accuracy and unchanged morphology, thereby ensuring the surface accuracy of the cycloidal gear workpiece. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the worm gear grinding machine in this invention;

[0019] Figure 2 This is a schematic diagram showing the contact position between the grinding wheel and the dresser when the dresser dresses the grinding wheel on a worm gear grinding machine.

[0020] Figure 3 This is a schematic diagram of the installation location of a contact vibration sensor;

[0021] Figure 4 This is a schematic diagram of a contact vibration sensor;

[0022] Marked in the image:

[0023] Machine tool base (1), CRT large turntable (2), workpiece turntable (3), workpiece (4), dresser mounting bracket (5), grinding wheel mounting bracket (6), Y guide rail (7), X guide rail (8), Z guide rail (9), grinding wheel (10), dresser (11), dresser rotating motor (12), workpiece clamping bracket (13), W guide rail (14), grinding wheel wire start end face (15), grinding wheel wire end end face (16), grinding wheel fixing screw (17), contact vibration sensor (18), dresser fixing screw (19), dresser mounting expansion shaft (20). Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings.

[0025] The present invention and its embodiments are described below. This description is not restrictive, and actual embodiments are not limited thereto. In short, if those skilled in the art are inspired by this description and, without departing from the spirit of the invention, design similar structures and embodiments to this technical solution, such designs should fall within the protection scope of the present invention.

[0026] This invention discloses a grinding wheel dressing method for grinding cycloidal gears using a worm gear grinding machine, ensuring that the obtained grinding wheel can be used to process high-precision cycloidal gears. In the preferred embodiment of this invention, right-hand grinding wheels are used; for left-hand grinding wheels, only the motion is reversed compared to right-hand grinding wheels, and therefore they are also within the protection scope of this patent.

[0027] In a preferred embodiment, the worm gear grinding machine has the following structure: Figure 1 As shown:

[0028] The CRT large turntable (2) is mounted on the machine tool base (1) and can rotate around the CRT axis of the turntable; the dresser mounting bracket (5) and the workpiece turntable (3) are mounted on the CRT large turntable (2); the dresser rotating motor (12) is mounted on the dresser mounting bracket (5), the output shaft of the dresser rotating motor (12) is the dresser mounting expansion shaft (20), the dresser (11) is fitted on the dresser mounting expansion shaft (20) and fixed by the dresser fixing screw (17), and the dresser (11) is driven by the dresser rotating motor (12); the workpiece (4) is mounted on the workpiece turntable (3) and can rotate around the C axis of the workpiece turntable; by rotating the CRT large turntable (2), the working positions of the dresser mounting bracket (5) and the workpiece turntable (3) can be adjusted to achieve rapid adjustment of the machine tool in two working states. When the worm gear grinding machine dresses the grinding wheel, the CRT large turntable (2) adjusts its working position so that the dresser mounting bracket (5) faces the grinding wheel (10) to dress the grinding wheel.

[0029] For worm gear grinding machines, repeated dressing of the grinding wheel will cause the outer diameter of the grinding wheel to decrease and the grinding wheel tooth profile to deviate from the theoretical tooth profile that is conjugate with the tooth profile of the workpiece during design, thus introducing errors into the workpiece. This kind of error inevitably exists in worm gear grinding machines. In a preferred embodiment of the present invention, the dresser mounting bracket (5) can rotate along the axis C2 of the dresser mounting bracket. The rotation and swing of the dresser mounting bracket (5) around the axis C2 is equivalent to increasing the degree of freedom of movement of the dresser (11) when the machine tool dresses the grinding wheel, so that the central axis B2 of the dresser (11) obtains a swing angle in the horizontal plane during dressing. As the number of dressings increases, the outer diameter of the grinding wheel becomes smaller and smaller, and the lead angle of the grinding wheel becomes larger and larger. The tooth profile of the cycloidal gear produced will also deviate from the theoretical tooth profile. The main deviation parameter is the pressure angle of the cycloidal gear. When the dresser (11) dresses the grinding wheel (10), it obtains a horizontal swing angle, which is equivalent to adjusting the pressure angle of the grinding wheel tooth profile. This achieves the purpose of adjusting the pressure angle of the cycloidal gear, reducing the impact of the reduced outer diameter of the grinding wheel and the theoretical tooth profile that deviates from the design and is conjugate with the tooth profile of the workpiece. At the same time, this swing angle can improve the installation error of the dresser to a certain extent, control the error generated when dressing the grinding wheel, improve the meshing characteristics of the grinding wheel (10) when machining the workpiece (4), and improve the stability of the machine tool during operation.

[0030] In a preferred embodiment of the present invention, the installation positions of the grinding wheel and the dresser are as follows: Figure 2 As shown, the installation position of the contact vibration sensor is as follows: Figure 3 As shown, the contact vibration sensor is as follows: Figure 4As shown. At the start of dressing, the grinding wheel (10) and the dresser (11) need to be set. Since the length of the grinding wheel (10) is a fixed value, when the machine tool dresses the grinding wheel, it only needs to move the Y-axis and Z-axis to align the end face (16) of the grinding wheel with the center end section of the dresser (11), and make the geometric center point of the end face (16) of the grinding wheel with the axis of the dresser on the same horizontal plane. Then the dresser (11) rotates in the positive direction around the spindle B2 axis; the grinding wheel (10) only moves in the negative direction of the X-axis, and the spindle B-axis is locked and does not rotate. Since the outer diameter of the dresser (11) is known, the current outer diameter of the grinding wheel (10) is known, and the machine tool can calculate the basic positional relationship between the current grinding wheel (10) and the dresser (11). When the grinding wheel (10) approaches the dresser (11), the feed rate of the X-guide (8) decreases, and the grinding wheel (10) approaches the dresser (11) at a low feed rate along the negative X-axis to avoid the machine tool colliding with the tool. When the grinding wheel (10) contacts the dresser (11), the contact vibration sensor (18) on the grinding wheel (10) senses the vibration. The machine tool records the X-axis position at this time and compares it with the sum of the outer radius of the grinding wheel (10) and the outer radius of the dresser (11): if the position is not in the valley of the grinding wheel tooth surface, the grinding wheel (10) slowly retracts along the positive X-axis, and then rotates the spindle B-axis by a certain angle (taking an n-head grinding wheel as an example, rotating pi / n radians), and repeats this step again; if the position is in the valley of the grinding wheel tooth surface, then proceed to the next step.

[0031] When the position is in the valley of the grinding wheel tooth surface, record the Y-axis position at this moment. Then the grinding wheel (10) moves in the negative Y-axis direction with a low feed rate. At this time, there are two contact states: If the contact vibration sensor (18) keeps sensing the vibration and the vibration intensifies with the movement of the grinding wheel (10), the grinding wheel (10) immediately moves along the Y guide rail (7) in the positive Y-axis direction with a low feed rate until the contact vibration sensor (18) senses the vibration again and stops moving. Record the Y-axis position at this time. The midpoint between the two positions is the centering position for this dressing. If the contact vibration sensor (18) immediately stops vibrating as the grinding wheel (10) moves along the Y guide rail (7) in the negative Y-axis direction with a low feed rate, and after the grinding wheel (10) slowly moves a distance in the negative Y-axis direction, the contact vibration sensor (18) detects the vibration again, record the Y-axis position at this time. The midpoint between the two positions is the centering position for this dressing.

[0032] After the machine tool finds the centering position when dressing the grinding wheel, it records the grinding wheel thread end at this position as the first thread end. The grinding wheel (10) performs a spiral motion according to the spiral parameters until the end face (16) of the grinding wheel thread end is aligned with the center end section of the dresser (11). The geometric center point of the end face (16) of the grinding wheel thread end is on the same horizontal plane as the axis of the dresser, which is the starting position of the grinding wheel thread end. Then the dresser begins to dress the grinding wheel.

[0033] The dressing process of the grinding wheel is divided into two stages to reduce errors caused by insufficient centering and indexing precision. The machining stages are divided into roughing and finishing stages, which differ in the amount of grinding and the movement of the grinding wheel.

[0034] For the roughing stage, the grinding wheel (10) is fed a grinding amount x1 in the negative X-axis direction, and the grinding wheel (10) moves in a helical motion in the positive Y-axis direction: that is, according to the designed helical parameters, the grinding wheel (10) rotates around the positive B-axis and moves in the positive Y-axis direction at the same time. The contact position between the dresser (11) and the grinding wheel (10) moves from the end face (16) of the grinding wheel tip to the beginning face (15) of the grinding wheel tip. Subsequently, the grinding wheel (10) is fed another grinding amount x1 in the negative X-axis direction, and the grinding wheel (10) moves in a helical motion in the negative Y-axis direction: that is, according to the designed helical parameters, the grinding wheel rotates around the negative B-axis and moves in the negative Y-axis direction at the same time. The contact position between the dresser (11) and the grinding wheel (10) moves from the beginning face (15) of the grinding wheel tip to the end face (16) of the grinding wheel tip. This process is one flow of the roughing stage. The movement mode of the grinding wheel in the roughing stage is reciprocating motion, reciprocating grinding.

[0035] The wire end has undergone a certain number of roughing operations, removing most of the excess material from this dressing process (the ratio of roughing allowance to finishing allowance can be 5:2; generally, a larger roughing allowance results in a larger grinding amount per process, achieving rapid removal of excess material), thus completing the roughing operation of the wire end. The grinding wheel (10) needs to return to the centering position and retract a certain distance along the positive X-axis until the cutting face of the dresser (11) completely exits the tooth surface of the grinding wheel (10), at which point the grinding wheel (10) is rotated and indexed. The grinding wheel (10) rotates clockwise around the spindle B-axis, i.e., around the positive B-axis, by 2π / n arcs, which is the starting position for the second wire end, without needing to be centered again.

[0036] After completing the above process, the dresser (11) finishes roughing the n-head spiral surface of the grinding wheel (10) and then begins the finishing stage.

[0037] After the above process is completed, the grinding wheel (10) returns to the processing position of the first wire end. At this moment, the grinding wheel (10) feeds a grinding amount x2 (x2 < x1) in the negative X-axis direction, and the grinding wheel (10) makes a spiral movement along the positive Y-axis direction: that is, according to the designed spiral parameters, the grinding wheel (10) rotates in the positive B-axis direction and moves in the positive Y-axis direction at the same time. The contact position of the dresser (11) and the grinding wheel (10) moves from the end face (16) of the wire end of the grinding wheel to the starting face (15) of the wire end of the grinding wheel. Subsequently, the grinding wheel retracts in the positive X-axis direction until the cutting face of the dresser (11) completely exits the tooth face of the grinding wheel (10). The grinding wheel (10) makes a spiral movement along the negative Y-axis direction. According to the designed spiral parameters, the grinding wheel (10) rotates in the negative B-axis direction and moves in the negative Y-axis direction at the same time, and returns to the position before processing. This process is a process at the fine machining level. It is repeated a certain number of times until the allowance at the fine machining level is completely removed and the tooth face morphology of the grinding wheel is good, that is, the fine machining of this wire end is completed. The movement mode at the fine machining level is a unidirectional movement, unidirectional grinding.

[0038] After machining the first wire end, the grinding wheel rotates and indexes to perform fine machining on the second wire end until fine machining of all wire ends is completed; after dressing the grinding wheel, the surface roughness of the cycloid gear to be machined needs to reach Ra0.4μm, and the dressing process is completed; otherwise, the grinding wheel needs to be reground and dressed again until the requirements are met.

Claims

1. A method for dressing a grinding wheel used in machining cycloidal gears using a worm gear grinding machine, characterized in that, include: This worm gear grinding machine integrates cycloidal gear machining and grinding wheel dressing functions, enabling the machine tool to switch between grinding and grinding wheel dressing modes. Using a worm gear grinding machine with an adjustable central axis swivel angle for the dresser increases the dresser's freedom of movement during grinding wheel dressing, reducing the impact of repeated dressing on the grinding wheel's outer diameter reduction and tooth profile separation from the theoretical tooth surface conjugate with the cycloidal gear's tooth profile during grinding wheel machining, and controlling errors generated during grinding wheel dressing. A contact vibration sensor mounted on the grinding wheel mounting bracket collects grinding wheel vibration data, guiding the machine tool to complete centering. After centering, the indexing rotation of the grinding wheel is calculated and controlled to accurately locate the starting position of the second thread end during machining, eliminating the need for re-indexing and centering. The machine distinguishes between two machining stages during grinding wheel dressing: the roughing stage quickly removes excess grinding wheel material, while the finishing stage maintains the grinding wheel's surface morphology.

2. According to claim 1, a grinding wheel dressing method for machining cycloidal gears using a worm gear grinding machine, the CRT large turntable (2) is mounted on the machine tool base (1) and can rotate around the CRT axis; the dresser mounting bracket (5) and the workpiece turntable (3) are mounted on the CRT large turntable (2); the dresser rotating motor (12) is mounted on the dresser mounting bracket (5), the output shaft of the dresser rotating motor (12) is the dresser mounting expansion shaft (20), the dresser (11) is sleeved on the dresser mounting expansion shaft (20) and fixed by the dresser. The screw (17) is fixed, and the dresser (11) is driven by the dresser rotation motor (12); the workpiece (4) is installed on the workpiece turntable (3) and can rotate around the workpiece turntable axis C; by rotating the CRT large turntable (2), the working position of the dresser mounting bracket (5) and the workpiece turntable (3) can be adjusted to quickly adjust the machine tool in two working states; when the worm gear grinding machine dresses the grinding wheel, the CRT large turntable (2) adjusts the working position so that the dresser mounting bracket (5) faces the grinding wheel (10) to dress the grinding wheel.

3. According to claim 2, the grinding wheel dressing method for machining cycloidal gears using a worm gear grinding machine, the dressing mount (5) can rotate with the axis C2 of the dressing mount; the rotation and swing of the dressing mount (5) around the axis C2 is equivalent to increasing the degree of freedom of movement of the dressing (11) when the machine tool dresses the grinding wheel: so that the central axis B2 of the dressing (11) obtains a swing angle in the horizontal plane during dressing, which is equivalent to adjusting the pressure angle of the grinding wheel tooth profile.

4. According to claim 3, a grinding wheel dressing method for machining cycloidal gears using a worm gear grinding machine, a contact vibration sensor (18) is installed on the grinding wheel mounting bracket (6). Before tool setting begins, the end face (16) of the grinding wheel tip is aligned with the center end section of the dresser (11) by moving along the Y and Z axes, and the geometric center point of the end face (16) of the grinding wheel tip is made to be on the same horizontal plane as the axis of the dresser; then the dresser (11) rotates in the positive direction around the spindle B2 axis; the grinding wheel (10) moves only in the negative X-axis direction. The spindle B axis is locked and does not rotate; when the grinding wheel (10) approaches the dresser (11), the feed rate of the X guide rail (8) decreases, and the grinding wheel (10) approaches the dresser (11) at a low feed rate along the negative X-axis. When the grinding wheel (10) contacts the dresser (11), the contact vibration sensor (18) on the grinding wheel (10) senses the vibration. The machine tool records the X-axis position at this time and compares it with the sum of the outer radius of the grinding wheel (10) and the outer radius of the dresser (11): if the position is not in the valley of the grinding wheel tooth surface, then the grinding wheel ( 10) Retract the tool along the positive X-axis at a low feed rate until it exits the grinding wheel tooth surface, then rotate the spindle B-axis by a certain angle and repeat this step; if the position is in the tooth profile valley of the grinding wheel, record the Y-axis position at this moment, and then the grinding wheel (10) moves in the negative Y-axis direction at a low feed rate. At this time, there are two contact states: if the contact vibration sensor (18) keeps sensing the vibration, and the vibration intensifies with the movement of the grinding wheel (10), then the grinding wheel (10) immediately moves along the Y guide rail (7) in the positive Y-axis direction at a low feed rate until it contacts the grinding wheel. When the contact vibration sensor (18) senses vibration again, it stops moving and records the Y-axis position at this time. The midpoint between the two positions is the centering position for this dressing. If the grinding wheel (10) moves along the Y-guide rail (7) in the negative Y-axis direction with a low feed rate, the contact vibration sensor (18) immediately stops vibrating. After the grinding wheel (10) moves a certain distance in the negative Y-axis direction with a low feed rate, when the contact vibration sensor (18) detects vibration again, it records the Y-axis position at this time. The midpoint between the two positions is the centering position for this dressing.

5. The grinding wheel dressing method for machining cycloidal gears using a worm gear grinding machine according to claim 4, wherein the grinding wheel dressing process is divided into two machining stages, the purpose of which is to reduce the error caused by insufficient centering and indexing accuracy; for the roughing stage, the grinding wheel (10) is fed in the negative X-axis direction by a grinding amount. x 1. The grinding wheel (10) makes a helical motion along the positive Y-axis: that is, according to the designed helical parameters, the grinding wheel (10) rotates around the positive B-axis and moves in the positive Y-axis direction. The contact position between the dresser (11) and the grinding wheel (10) moves from the end face (16) of the grinding wheel tip to the beginning face (15) of the grinding wheel tip. Then, the grinding wheel (10) feeds a grinding amount in the negative X-axis direction. x 1. The grinding wheel (10) makes a spiral motion along the negative Y-axis: that is, according to the designed spiral parameters, the grinding wheel rotates around the negative B-axis and moves towards the negative Y-axis. The contact position between the dresser (11) and the grinding wheel (10) moves from the starting end face (15) of the grinding wheel to the ending end face (16) of the grinding wheel. This process is a roughing stage. The movement mode of the roughing stage grinding wheel is reciprocating motion and reciprocating grinding. The grinding wheel is processed through a certain number of roughing stages until most of the grinding wheel's allowance is removed, thus completing the roughing stage. The grinding wheel (10) needs to return to the centering position and retract a certain distance along the positive X-axis until the cutting face of the dresser (11) completely exits the tooth surface of the grinding wheel (10). The grinding wheel (10) then rotates and indexes. The grinding wheel (10) rotates clockwise around the spindle B-axis, that is, around the positive B-axis. pi / n The arc is the starting position for machining the second wire end, and no re-alignment is required; subsequently, the grinding wheel (10) returns to the machining position of the first wire end, and at this moment the grinding wheel (10) feeds a grinding amount in the negative X-axis direction. x 2, x 2< x 1. The grinding wheel (10) makes a helical motion along the positive Y-axis: that is, according to the designed helical parameters, the grinding wheel (10) rotates around the positive B-axis and moves towards the positive Y-axis at the same time. The contact position between the dresser (11) and the grinding wheel (10) moves from the end face (16) of the grinding wheel tip to the beginning face (15) of the grinding wheel tip. Then, the grinding wheel retracts in the positive X-axis direction until the cutting face of the dresser (11) completely exits the tooth surface of the grinding wheel (10). The grinding wheel (10) makes a helical motion along the negative Y-axis: the grinding wheel (10) rotates around the negative B-axis and moves towards the negative Y-axis at the same time. The grinding wheel moves to its original position before machining; this process is one step in the finishing stage, and is repeated a certain number of times until the finishing stage allowance is completely removed, thus completing the finishing of the thread end; the movement mode of the finishing stage is unidirectional motion and unidirectional grinding; after machining the first thread end, the grinding wheel rotates to index and finishes the second thread end, until all thread ends are finished; after dressing the grinding wheel, the surface roughness of the machined cycloidal gear teeth must reach Ra0.4μm, and the dressing process is complete; otherwise, the grinding wheel needs to be regrinded and dressed again until the requirements are met.

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