Rotor shaft skewed slot machining process

Abstract

The invention discloses a rotor shaft skewed slot machining process, which comprises the following steps of: machining a rotor shaft by adopting a turn-milling composite machine tool, enabling a formed milling cutter to synchronously move along the axial direction and the circumferential direction of the rotor shaft by using the formed milling cutter and through a multi-shaft linkage function of the turn-milling composite machine tool, and matching with the rotation of a workpiece in a skewed line interpolation manner, so as to finish the skewed slot machining of the rotor shaft. And a continuous chute is directly milled on the surface of the rotor shaft. The machining process comprises the following steps of: performing copper plating treatment after turning of the rotor base body, and milling the skewed slot on the copper plating layer. The invention provides a rotor shaft chute processing technology. The technology aims at solving the problems that in an existing machining method, disassembling and assembling are conducted many times, programming and tool setting are conducted many times, the working procedure is tedious, efficiency is low, and precision is difficult to guarantee, and one-time clamping, efficient and high-precision forming of the skewed slot is achieved by optimizing the technology route and the machining strategy.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and specifically to a rotor shaft inclined groove machining process. Background Technology

[0002] High-speed air-bearing rotors have important applications in modern precision equipment, and their performance directly affects the stability and accuracy of the equipment. To optimize the dynamic pressure film performance of the air bearing while taking into account the rotor's electrical performance and mechanical strength, the copper-plated grooves on the rotor surface are often machined into inclined grooves with a certain helix angle during the design process. This inclined groove structure can effectively improve the distribution and stability of airflow, enhance the film bearing capacity, and optimize the electromagnetic characteristics of the rotor.

[0003] However, machining such high-precision skewed grooves faces numerous challenges in existing technologies. Traditional machining methods often require multiple clamping and disassembly of the workpiece, performing turning, milling, and other processes on different machine tools. This not only results in a lengthy and inefficient process flow, but each re-clamping introduces new positioning errors, making it difficult to guarantee the precise angle, continuity, and coaxiality of the skewed groove. Furthermore, for machining soft materials like copper plating, improper process parameters can easily lead to problems such as burrs, tool sticking, or copper layer tearing, affecting the performance and reliability of the final product.

[0004] Therefore, there is an urgent need for a process that can be integrated and complete high-precision slant machining in a single setup, in order to simplify operation, reduce costs and ensure machining quality. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a machining process for rotor shaft inclined slots. This process aims to solve the problems of multiple disassembly and assembly, multiple programming and tool setting, cumbersome procedures, low efficiency, and difficulty in guaranteeing accuracy in existing machining methods. By optimizing the process route and machining strategy, it achieves one-time clamping, high-efficiency, and high-precision forming of the inclined slot.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A rotor shaft inclined groove machining process is characterized by using a turning-milling composite machine tool to machine the rotor shaft, using a forming milling cutter and through the multi-axis linkage function of the turning-milling composite machine tool, making the forming milling cutter move synchronously along the axial and circumferential directions of the rotor shaft, and coordinating with the rotation of the workpiece in an oblique interpolation manner to directly mill a continuous inclined groove on the surface of the rotor shaft.

[0007] Furthermore, the processing technology includes copper plating after the rotor substrate is turned, and then milling the inclined groove on the copper plating layer.

[0008] Furthermore, process planning is carried out before machining, including: determining the spiral lead, tilt angle, groove width, depth, and copper plating thickness parameters of the inclined groove; and planning a cutting path that uses oblique interpolation and is linked to the workpiece rotation axis.

[0009] Furthermore, the rotor shaft is clamped using a hydraulically tightened mandrel to ensure that the coaxiality of the clamping is within 0.005mm and that the rotor axis coincides with the Z-axis of the machine tool.

[0010] Furthermore, the profile shape of the forming milling cutter matches the cross-sectional shape of the inclined groove to be machined; the cutter body of the forming milling cutter is made of cemented carbide, and the cutting edge is titanium-plated; the diameter of the forming milling cutter is 0.01-0.02 mm smaller than the width of the inclined groove.

[0011] Furthermore, the cutting parameters during milling include: milling cutter speed of 1600 r / min; feed rate of 0.05-0.1 mm / tooth; and the cutting depth is completed in two stages: the first stage is rough milling to remove most of the excess material, and the second stage is finish milling to the final size and ensuring that the surface roughness Ra of the groove is Ra≤0.8μm.

[0012] Furthermore, a workpiece coordinate system is established on the milling and turning machine tool, and the tilt angle of the skew groove is matched by the coordinate system rotation command; the tool path is simulated and verified by no-load operation before machining.

[0013] Furthermore, high-pressure cooling is activated during the machining process, with a coolant pressure of 0.8-1 MPa, to cool the cutting tool and workpiece and flush away chips.

[0014] Furthermore, the dimensions of the inclined groove are inspected after processing. When the dimensional deviation exceeds the allowable range, it is corrected by adjusting the rotation angle of the workpiece rotation axis or the tool compensation value.

[0015] Furthermore, after the milling process is completed, the groove wall of the inclined groove is polished.

[0016] Compared with existing technologies, the technical solution of this patent achieves the following beneficial effects: 1. This invention integrates multiple processes into a single setup on a milling and turning machine tool, achieving a simplified process of "setting the program - single tool setting - product output", avoiding multiple disassembly, programming, and tool setting, greatly improving processing efficiency and reducing labor and time costs.

[0017] 2. By using high-precision hydraulic mandrel clamping and multi-axis linkage interpolation control of the machine tool, the cumulative error caused by repeated positioning is effectively reduced, ensuring the stability and consistency of the spiral angle, groove size and position accuracy of the inclined groove, and significantly improving product accuracy.

[0018] 3. Based on the characteristics of the copper plating material, the forming milling cutter and cutting parameters are optimized, and high-pressure cooling is used to effectively suppress the generation of burrs and the phenomenon of copper chips sticking to the cutter during processing. The surface roughness of the groove wall can be controlled at Ra≤0.8μm, which meets the requirements of high-end air-floating rotors.

[0019] 4. Standardized process steps reduce the professional skill requirements for operators and decrease human error; simulation verification and process monitoring ensure the safety and reliability of the processing. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the processing technology of the present invention; Figure 2 A schematic diagram of the main structure of the rotor shaft inclined groove; Figure 3 This is a cross-sectional view of the rotor shaft inclined groove. Figure 4 This is a schematic diagram showing the machining position relationship between the form milling cutter and the workpiece. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1, such as Figures 1 to 4 As shown, this embodiment takes the machining of a certain type of high-speed air-bearing rotor shaft inclined groove as an example to explain the implementation process of the present invention in detail. A rotor shaft inclined groove machining process, using a milling-turning composite machine tool, includes the following steps: S1. Process planning and preparation before processing: Analyze the workpiece drawings to clarify key parameters such as the spiral lead, tilt angle, groove width, depth, and copper plating thickness of the inclined groove; determine the machining sequence: first complete the turning of the rotor base (outer circle and end face), then perform surface copper plating with a copper layer thickness of 0.05-0.2mm, and finally machine the inclined groove to avoid damage to the copper plating layer during the earlier machining process; plan the tool path and adopt a machining strategy that links oblique interpolation with the machine tool B-axis (workpiece rotation axis).

[0023] S2. Workpiece clamping and positioning: The rotor workpiece is clamped using a high-precision hydraulic expansion mandrel to ensure that the coaxiality of the clamping is ≤0.005mm, thus avoiding slot offset caused by eccentricity during processing. The rotor workpiece is then corrected so that its axis coincides with the Z-axis of the machine tool. A dial indicator is used to calibrate the outer circle and end face of the workpiece to ensure that its radial runout and end face runout are both less than 0.005mm. The origin of the workpiece coordinate system is then set at the center of the end face.

[0024] S3. Tool Selection and Parameter Settings: A form milling cutter with a profile shape matching the cross-sectional shape of the skew groove is selected. The cutter material is cemented carbide, and the cutting edge is titanium-plated to reduce adhesion wear with the copper layer. The cutter diameter is selected according to the groove width, usually 0.01-0.02 mm smaller than the designed groove width to allow for subsequent polishing. Cutting parameters are set as follows: considering the cutting characteristics of the iron layer, the milling cutter spindle speed is approximately 1600 r / min, and the rotor B-axis rotation speed is calculated based on the skew groove lead to ensure uniform cutting speed. The feed rate is 0.05-0.1 mm / tooth to avoid tearing of the iron layer and burr formation due to excessive feed rate. The cutting depth is completed in two stages: the first rough milling removes most of the excess material, and the second finish milling is performed to the final size, ensuring that the surface roughness Ra of the groove is ≤0.8 μm.

[0025] S4. Programming and machining operations: A workpiece coordinate system is established on the milling and turning machine, and the inclination angle of the skew groove is set by the coordinate system rotation command. The linkage interpolation of the Z-axis (axial) and B-axis (rotation) is implemented by programming to drive the forming milling cutter to continuously cut along the preset skew trajectory. Before machining, tool path simulation and no-load run verification are performed to verify the linkage accuracy of the B-axis and Z-axis. During machining, high-pressure cooling (pressure 0.8-1MPa) is turned on, and emulsion is used to cool the tool and workpiece to prevent copper chips from sticking to the cutting edge. At the same time, the cutting status is monitored in real time, and the feed rate is adjusted immediately if burrs appear.

[0026] S5. Post-processing inspection and treatment: The tilt angle, width, and depth of the inclined groove are detected using equipment such as a 2D image analyzer. If there are any deviations, they are corrected by adjusting the program parameters or tool compensation. Finally, diamond polishing paste is used to polish the groove wall to remove micro-burrs and ensure surface smoothness, thereby ensuring the smooth airflow of the air bearing shaft during operation.

[0027] Example 2: This example provides a rotor shaft inclined slot machining process that is basically the same as Example 1, except that the pre-machining process planning step includes optimizing the inclined angle and / or slot depth / width ratio of the inclined slot based on the target aerodynamic performance parameters of the rotor shaft through fluid dynamics simulation, and using the optimized parameters as input for machining planning. Specific operation: Before CAM programming, fluid simulation software is used to preliminarily analyze the influence of different inclined angles and slot depth / width ratios on air film formation and stability based on the rotor's operating speed, load, and other conditions. The optimal performance parameter range obtained from the simulation is compared and integrated with the theoretical design parameters in the drawings to generate the final optimized parameter set for machining. For example, the simulation may show that, under the current operating conditions, fine-tuning the inclined angle from the theoretical 15° to 15.5° can significantly improve air film stability. Subsequent linkage programs will then be generated based on this optimized 15.5°. This technique tightly closes the performance design and manufacturing execution loop, moving beyond simple machining according to drawings. It embodies cross-disciplinary aerodynamics + precision manufacturing customized process design for optimizing air flotation performance. Conventional machining processes aim to meet drawing tolerances. This paper proposes a further approach, aiming to achieve optimal performance through active simulation and parameter fine-tuning.

[0028] Example 3: This example provides a rotor shaft skew groove machining process that is basically the same as Example 1, except that a vibration sensor or acoustic emission sensor is installed on the machine tool spindle head or workpiece fixture. During the milling process, the vibration or acoustic emission signal of the cutting system is monitored in real time. When the monitored signal exceeds a preset threshold, the machine tool control system automatically adjusts the feed rate or spindle speed in the linkage machining to bring the vibration signal back below the threshold. A vibration threshold corresponding to good surface quality is set. When the signal amplitude exceeds the threshold, the control system does not simply stop the machine, but adaptively fine-tunes the linkage machining parameters. When the vibration increases, the system automatically reduces the feed rate by a preset ratio (e.g., 5%-10%), and gradually restores it to the original feed rate after the vibration signal stabilizes. The introduction of a real-time monitoring and adaptive adjustment mechanism enables traditional CNC machining to have preliminary intelligent decision-making capabilities based on physical signal feedback.

Claims

1. A machining process for a rotor shaft inclined groove, characterized in that, The rotor shaft is machined using a milling and turning machine tool. A forming milling cutter is used, and through the multi-axis linkage function of the milling and turning machine tool, the forming milling cutter moves synchronously along the axial and circumferential directions of the rotor shaft. The forming milling cutter is used in conjunction with the rotation of the workpiece in a diagonal interpolation manner to directly mill a continuous diagonal groove on the surface of the rotor shaft.

2. The rotor shaft inclined groove machining process according to claim 1, characterized in that, The processing technology includes copper plating after the rotor substrate is turned, and then milling the inclined groove on the copper plating layer.

3. The rotor shaft inclined groove machining process according to claim 2, characterized in that, Before processing, process planning is carried out, including: determining the spiral lead, tilt angle, groove width, depth, and copper plating thickness parameters of the inclined groove; and planning a cutting path that uses oblique interpolation and is linked to the workpiece rotation axis.

4. The rotor shaft inclined groove machining process according to claim 1 or 2, characterized in that, The rotor shaft is clamped using a hydraulically tightened mandrel to ensure that the coaxiality of the clamping is within 0.005mm and that the rotor axis coincides with the Z-axis of the machine tool.

5. The rotor shaft inclined groove machining process according to claim 2 or 3, characterized in that, The profile shape of the forming milling cutter matches the cross-sectional shape of the inclined groove to be machined; the cutter body of the forming milling cutter is made of cemented carbide, and the cutting edge is titanium-plated; the diameter of the forming milling cutter is 0.01-0.02 mm smaller than the width of the inclined groove.

6. The rotor shaft inclined groove machining process according to claim 2 or 3, characterized in that, The cutting parameters during milling include: milling cutter speed of 1600 r / min; feed rate of 0.05-0.1 mm / tooth; the cutting depth is completed in two stages, the first rough milling removes most of the excess material, and the second finish milling is performed to the final size and ensures that the surface roughness Ra of the groove is Ra≤0.8μm.

7. The rotor shaft inclined groove machining process according to claim 1 or 2, characterized in that, A workpiece coordinate system is established on the milling and turning machine tool, and the tilt angle of the skew groove is matched by the coordinate system rotation command; the tool path is simulated and verified by no-load operation before machining.

8. The rotor shaft inclined groove machining process according to claim 1 or 2, characterized in that, High-pressure cooling is activated during the machining process, with a coolant pressure of 0.8-1 MPa, to cool the cutting tool and workpiece and flush away chips.

9. The rotor shaft inclined groove machining process according to claim 1 or 2, characterized in that, After processing, the dimensions of the inclined groove are inspected. When the dimensional deviation exceeds the allowable range, it is corrected by adjusting the rotation angle of the workpiece rotation axis or the tool compensation value.

10. The rotor shaft inclined groove machining process according to claim 1 or 2, characterized in that, After the milling process is completed, the groove wall of the inclined groove is polished.

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