Twisted blade type Roots blower rotor machining device and working method thereof

Abstract

The invention discloses a twisted blade type Roots blower rotor machining device and a working method thereof, and relates to the technical field of machining. The machining device comprises a rack, a rotor fixing mechanism, a rotor machining mechanism and a driving control system. The rotor fixing mechanism is provided with double parallel spindles used for clamping a pair of rotor blanks. The rotor machining mechanism comprises an installation platform and three forming tools arranged side by side, wherein the second forming tool can move transversely. The method comprises the steps that through transverse switching of cutters and synchronous indexing of a main shaft, cooperative machining is conducted in two strokes, the three cutters participate in cutting of two rotors in a balanced mode, and machining of six spiral grooves of a pair of rotors is completed at a time. The problems that traditional machining efficiency is low, pairing precision is difficult to guarantee, and tool abrasion is uneven are solved, and efficient and high-precision synchronous machining of paired rotors and balanced maintenance of tools are achieved.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a machining device for a twisted-blade Roots blower rotor and its working method. Background Technology

[0002] Roots blowers, as a type of positive displacement blower, are widely used in environmental protection, power, chemical, and aquaculture fields due to their simple structure, stable operation, and constant output pressure. Their core component is a pair of meshing rotors. Traditional straight-blade rotors are prone to generating significant airflow pulsation and noise during operation. To improve this problem, a twisted-blade rotor with a three-dimensional helical structure was proposed. Through progressive meshing and exhaust, it can significantly reduce pulsation and noise. However, the complex helical surface of the twisted-blade rotor also presents a significant challenge to its high-precision, high-efficiency mass production.

[0003] Currently, for parts with complex helical surfaces, the industry generally uses multi-axis CNC machining centers or dedicated forming equipment for processing. These technologies, through precise computer programs that coordinate and control the relative movement of the tool and the workpiece in multiple dimensions, have enabled the forming of complex spatial surfaces, solving the problem of going from being unable to process them to being able to process them.

[0004] However, directly applying this type of versatile CNC solution to the mass production of twisted-blade Roots blower rotors still has significant shortcomings: First, the processing efficiency is low. Typically, only individual rotors can be processed one by one. For Roots blowers that require precise pairing, the overall output efficiency is low and it is difficult to meet the needs of large-scale production. Second, the pairing accuracy is difficult to reliably guarantee. The two rotors are processed separately and independently. Machine tool errors, clamping errors, and tool wear errors are independent of each other and accumulate, resulting in poor consistency of the final meshing phase of the two rotors, which seriously affects the blower's performance and noise level. Third, the production cost and maintenance complexity are high. In batch processing, tool wear is inevitable. However, in the traditional method, the cutting tasks of each tool are uneven, and the wear conditions are different. This leads to the need for frequent machine stops to inspect, replace, and re-set individual tools. The stability and predictability of the production line are poor, and the maintenance cost is high. Summary of the Invention

[0005] Purpose of the Invention: The purpose of this invention is to provide a machining device and its working method for a torsion vane Roots blower rotor, aiming to solve the problems of low machining efficiency, poor pairing accuracy, and complex tool maintenance in existing technologies. Through a three-tool, dual-station synchronous machining design, it achieves efficient one-time forming of paired rotors, precise phase control, and balanced tool wear, resulting in significant improvements in efficiency, enhanced precision, and simplified maintenance.

[0006] Technical solution:

[0007] A rotor processing device for a twisted-blade Roots blower includes a frame, a rotor fixing mechanism, a rotor processing mechanism, and a drive control system.

[0008] The rotor fixing mechanism includes a first main shaft for clamping a first rotor blank and a second main shaft for clamping a second rotor blank. The first main shaft is connected to a first drive motor for controlling its rotation, and the second main shaft is connected to a second main shaft for controlling its rotation. The first main shaft and the second main shaft are arranged in parallel.

[0009] The rotor machining mechanism includes:

[0010] The mounting platform is mounted on the frame via linear guide rails and can be driven to reciprocate in a direction parallel to the axes of the first and second spindles; a control component is used to control the movement of the mounting platform; a first forming tool, a second forming tool, and a third forming tool are fixedly mounted side by side on the mounting platform, with their arrangement direction perpendicular to the movement direction of the mounting platform; the cutting edge shape of the first forming tool, the second forming tool, and the third forming tool is consistent with the radial cross-sectional profile of the groove between adjacent blades of the target twisted blade rotor;

[0011] The drive control system is electrically connected to the first drive motor, the second drive motor, and the control component.

[0012] Furthermore, the second forming tool is located between the first forming tool and the third forming tool, and the second forming tool is connected to a lateral movement assembly that controls lateral movement along a direction perpendicular to the moving direction of the mounting platform.

[0013] Furthermore, the lateral movement component is a linear motor.

[0014] Furthermore, the first forming tool, the second forming tool, and the third forming tool are forming milling cutters or forming planers.

[0015] Furthermore, both the first drive motor and the second drive motor are servo motors equipped with high-precision angle encoders.

[0016] Furthermore, the control component includes a third drive motor and a ball screw pair that is drively connected to the third drive motor.

[0017] Furthermore, the drive control system is configured to control the first drive motor and the second drive motor to rotate synchronously at an angular velocity ω during the processing, and to synchronously control the mounting platform to move axially at a linear velocity v, wherein the ratio of the linear velocity v to the angular velocity ω, v / ω, corresponds to the helix angle β of the target twisted blade rotor.

[0018] This invention also discloses a method for operating the above-mentioned torsion blade type Roots blower rotor processing device, comprising the following steps:

[0019] S1. Clamping and preparation: Clamp the first rotor blank on the first spindle and clamp the second rotor blank on the second spindle; control the transverse movement assembly of the second forming tool to move it laterally to the first transverse position corresponding to the processing position of the first rotor blank;

[0020] S2. First processing: Control the movement of the mounting platform to align the first forming tool and the second forming tool with the first rotor blank axially, and the third forming tool with the second rotor blank axially; control each forming tool to perform processing actions, and simultaneously control the first drive motor and the second drive motor to synchronously drive the rotor blank to rotate at an angular velocity ω, and control the mounting platform to move axially at a linear velocity v; thereby, two helical grooves are synchronously processed on the first rotor blank, and one helical groove is processed on the second rotor blank.

[0021] S3. Switching and Indexing: Control each forming tool to stop processing and retract from the workpiece; control the transverse traverse assembly to drive the second forming tool to move laterally to the second transverse position corresponding to the processing position of the second rotor blank; control the first drive motor and the second drive motor to synchronously drive the first spindle and the second spindle to rotate by a predetermined indexing angle.

[0022] S4. Second processing: Control the movement of the mounting platform so that the first forming tool is axially aligned with the first rotor blank, and the second and third forming tools are axially aligned with the second rotor blank; control each forming tool to perform processing actions, and at the same time repeat the workpiece rotation and platform axial movement in step S2; thereby, the last spiral groove is processed on the first rotor blank, and the remaining two spiral grooves are processed simultaneously on the second rotor blank.

[0023] Furthermore, after the first processing is completed, an in-machine measurement and compensation operation is performed. That is, the actual phase of the two helical grooves processed on the first rotor blank and the one helical groove processed on the second rotor blank are measured by an independent measuring device, and a compensation value is calculated based on the deviation between the actual phase and the theoretical phase. In the switching and indexing step, the compensation value is superimposed on the predetermined angle to correct the actual indexing command.

[0024] Furthermore, it also includes the following steps S5, batch processing and tool management: continuously execute steps S1 to S4 to batch process multiple pairs of twisted blade rotors, record the number of processing cycles, and when the number of processing cycles reaches a preset threshold, determine that the wear of the first forming tool, the second forming tool and the third forming tool has reached the balanced replacement standard, and replace all three with new tools at the same time.

[0025] Beneficial effects:

[0026] 1. Through a unique three-tool dual-station layout and parallel dual-spindle design, the machining of all six helical grooves of a pair of rotors can be completed simultaneously in a single setup using two collaborative machining strokes. This fundamentally changes the traditional serial machining mode, transforming it into a highly efficient parallel machining mode. The time to machine a pair of rotors is close to the time to machine a single rotor, resulting in a revolutionary improvement in production efficiency, which is especially suitable for mass production scenarios.

[0027] 2. The machining process designed in this invention ensures that the cutting tasks and wear conditions of the three forming tools are completely equal when machining a pair of rotors. This balanced wear characteristic brings two core advantages: First, it ensures the stability of batch product dimensions throughout the entire tool life cycle; second, it makes tool management extremely simple and predictable. Planned synchronous replacement of the three tools can be performed based on simple machining cycle counting, avoiding the complex individual tool life monitoring and frequent adjustments required in traditional methods. This greatly reduces unplanned downtime, lowers long-term maintenance costs and complexity, and significantly improves the overall efficiency and economic benefits of the production line. Attached Figure Description

[0028] Figure 1 This is the three-dimensional representation of the present invention. Figure 1 ;

[0029] Figure 2 This is the three-dimensional representation of the present invention. Figure 2 ;

[0030] Figure 3 This is a partial enlargement of the present invention. Figure 1 ;

[0031] Figure 4 This is a partial enlargement of the present invention. Figure 2 ;

[0032] Figure 5 This is a side view of the present invention. Figure 1 ;

[0033] Figure 6 This is a side view of the present invention. Figure 2 . Detailed Implementation

[0034] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] like Figure 1-6 As shown, a rotor processing device for a twisted blade Roots blower includes a frame 1, a rotor fixing mechanism 2, a rotor processing mechanism 3, and a drive control system 4.

[0037] The rotor fixing mechanism 2 includes a first main shaft 21 for clamping the first rotor blank and a second main shaft 22 for clamping the second rotor blank. The first main shaft 21 is connected to a first drive motor 23 for controlling its rotation, and the second main shaft 22 is connected to a second main shaft 24 for controlling its rotation. The first main shaft 21 and the second main shaft 22 are arranged in parallel. This parallel double main shaft design accurately simulates the working layout of a pair of rotors in a Roots blower. The center distance is fixed, ensuring that the two rotors are in the correct relative spatial position at the beginning of processing, laying the foundation for subsequent precise synchronous processing.

[0038] The rotor processing mechanism 3 includes:

[0039] The mounting platform 31 is mounted on the frame 1 via linear guide rails and can be driven to reciprocate along a direction parallel to the axes of the first main shaft 21 and the second main shaft 22.

[0040] Control component 32 is used to control the movement of the mounting platform 31;

[0041] The first forming tool 331, the second forming tool 332, and the third forming tool 333 are fixedly mounted side by side on the mounting platform 31, and their arrangement direction is perpendicular to the moving direction of the mounting platform 31. The cutting edge shape of the first forming tool 331, the second forming tool 332, and the third forming tool 333 is consistent with the radial cross-sectional profile of the groove between adjacent blades of the target twisted blade rotor. This arrangement allows the three tools to move axially as a whole unit with the mounting platform 31. At the same time, the cutting edge shape of each tool directly determines the cross-sectional shape of the processed spiral groove, and a continuous spiral groove surface can be formed on the workpiece in one axial stroke.

[0042] The drive control system is electrically connected to the first drive motor 23, the second drive motor 24, and the control component 32. The drive control system 4 acts as the central hub, coordinating all motion units, receiving encoder feedback, and executing pre-set machining programs to ensure that the entire machining process strictly follows the required kinematic relationships.

[0043] The second forming tool 332 is located between the first forming tool 331 and the third forming tool 333. The second forming tool 332 is connected to a transverse movement assembly 334 that controls its lateral movement along a direction perpendicular to the moving direction of the mounting platform 31. The transverse movement assembly 334 allows the second forming tool 332 to switch between two fixed machining stations. This is the core mechanism for redistributing the cutting task on the two rotors during two machining strokes, thereby achieving complete machining of the six helical grooves on the two rotors with the fewest possible tools.

[0044] The transverse movement component 334 is a linear motor. Using a linear motor as the drive source enables high-speed, high-precision transverse positioning of the second forming tool 332, with fast response, no backlash, and ensures accurate station switching and repeatability.

[0045] The first forming tool 331, the second forming tool 332, and the third forming tool 333 are forming milling cutters or forming planers. Forming milling cutters perform continuous cutting through self-rotation, suitable for requirements of high efficiency and high surface quality; forming planers perform linear reciprocating cutting. The specific choice depends on material, precision, and efficiency requirements. When selecting a forming milling cutter, a motor to control its rotation and a cylinder to control its lifting are required; when selecting a forming planer, a cylinder to control its lifting is sufficient.

[0046] Both the first drive motor 23 and the second drive motor 24 are servo motors equipped with high-precision angle encoders. The high-precision servo motors, in conjunction with the angle encoders, enable closed-loop precise control of the rotation angle and speed of the first spindle 21 and the second spindle 22. This is crucial for ensuring strict synchronous rotation and precise indexing of the two rotors.

[0047] The control component 32 includes a third drive motor 321 and a ball screw assembly 322 that is connected to the third drive motor. The third drive motor 321 drives the ball screw assembly 322 to convert the rotational motion into a smooth and precise linear axial movement of the mounting platform 31, providing precise axial feed for the machining of the spiral groove.

[0048] The drive control system is configured to control the first drive motor 23 and the second drive motor 24 to rotate synchronously at an angular velocity ω during machining, and to synchronously control the mounting platform 31 to move axially at a linear velocity v, wherein the ratio of linear velocity v to angular velocity ω, v / ω, corresponds to the helix angle β of the target torsion rotor. This configuration is the core control logic for generating precise helical motion. The ratio v / ω determines the lead of the helix. By precisely setting and maintaining this ratio constant, it is ensured that the relative trajectory of the tool moving axially strictly conforms to the mathematical definition of the target helix angle while the workpiece rotates, thereby machining a theoretically correct helical surface.

[0049] Example 2

[0050] This invention also discloses a method for operating the above-mentioned torsion blade type Roots blower rotor processing device, comprising the following steps:

[0051] S1. Clamping and preparation: Clamp the first rotor blank on the first spindle 21 and clamp the second rotor blank on the second spindle 22; control the transverse movement assembly 334 of the second forming tool 332 to move it laterally to the first transverse position corresponding to the processing position of the first rotor blank; this step completes the physical preparation before processing. The transverse movement assembly 334 positions the second forming tool 332 to the initial position, which is ready for the task allocation of the tool in the first processing.

[0052] S2. First Processing: Control the movement of the mounting platform 31 so that the first forming tool 331 and the second forming tool 332 are axially aligned with the first rotor blank, and the third forming tool 333 is axially aligned with the second rotor blank. Control each forming tool to perform processing actions, and simultaneously control the first drive motor 23 and the second drive motor 24 to synchronously drive the rotor blank to rotate at an angular velocity ω, and control the mounting platform 31 to move axially at a linear velocity v. Thus, two helical grooves are synchronously processed on the first rotor blank, and one helical groove is processed on the second rotor blank. In this step, the two rotors rotate in complete synchronization under the drive of the spindle, while the mounting platform 31 drives all tools to perform axial feed motion Z. The first forming tool 331 and the second forming tool 332, located in the first transverse position, jointly cut the first rotor, while the third forming tool 333 cuts the second rotor alone. Since the speed ratio v / ω is constant, a continuous groove with the correct helix angle is processed on each rotor.

[0053] S3. Switching and Indexing: Control each forming tool to stop processing and retract from the workpiece; control the transverse traverse assembly 334 to drive the second forming tool 332 to move laterally to the second transverse position corresponding to the processing position of the second rotor blank; control the first drive motor 23 and the second drive motor 24 to synchronously drive the first spindle 21 and the second spindle 22 to rotate by a predetermined angle; this step is a key transition to realize the processing of the remaining grooves. Tool retraction avoids interference, the action of the transverse traverse assembly 334 changes the service object of the second forming tool 332, and the synchronous indexing of the dual spindles makes the processed grooves and unprocessed areas on the workpiece reach a new correct phase relative to the tool.

[0054] S4. Second Processing: Control the movement of the mounting platform 31 so that the first forming tool 331 is axially aligned with the first rotor blank, and the second forming tool 332 and the third forming tool 333 are axially aligned with the second rotor blank. Control each forming tool to perform processing actions, while repeating the workpiece rotation and platform axial movement in step S2. Thus, the last helical groove is machined on the first rotor blank, and the remaining two helical grooves are simultaneously machined on the second rotor blank. After the reconfiguration in S3, the first forming tool 331 now completes the machining of the last groove on the first rotor alone, while the second forming tool 332 (now moved to the new station) and the third forming tool 333 jointly complete the machining of the remaining two grooves on the second rotor. At this point, all six helical grooves on a pair of rotors have been machined.

[0055] After the first machining is completed, in-machine measurement and compensation operations are performed. This involves using an independent measuring device to measure the actual phase of the two machined helical grooves on the first rotor blank and the one machined helical groove on the second rotor blank. A compensation value is calculated based on the deviation between the actual and theoretical phases. This compensation value is then superimposed on the predetermined angle during the switching and indexing steps to correct the actual indexing command. This closed-loop compensation mechanism proactively identifies and corrects machining phase errors caused by machine tool errors, tool wear, or clamping deviations. By measuring the actual position of the machined grooves and comparing it with the theoretical model, the required indexing angle compensation is calculated and implemented during indexing in S3. This ensures a precise phase relationship between the grooves machined in the second machining step and those machined in the first step, significantly improving the pairing accuracy between a pair of rotors.

[0056] The processing method also includes the following steps S5: batch processing and tool management: Steps S1 to S4 are executed continuously to batch process multiple pairs of twisted blade rotors, and the number of processing cycles is recorded. When the number of processing cycles reaches a preset threshold, it is determined that the wear of the first forming tool 331, the second forming tool 332, and the third forming tool 333 has reached the balanced replacement standard, and all three are replaced with new tools simultaneously. This method demonstrates the maintenance advantages of the present invention in large-scale production. Since all three tools participate in the cutting of two rotors during the processing of each pair of rotors, their wear naturally tends to be balanced. Therefore, tool life can be predicted based on a unified processing cycle count, and planned synchronous replacement can be performed. This avoids the drawbacks of traditional methods that require frequent shutdowns, individual inspections, and replacements due to uneven tool wear, significantly improving equipment utilization and reducing maintenance complexity and costs.

[0057] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A processing device for a twisted-blade Roots blower rotor, characterized in that, It includes a frame (1), a rotor fixing mechanism (2), a rotor processing mechanism (3), and a drive control system (4); The rotor fixing mechanism (2) includes a first main shaft (21) for clamping the first rotor blank and a second main shaft (22) for clamping the second rotor blank. The first main shaft (21) is connected to a first drive motor (23) for controlling its rotation, and the second main shaft (22) is connected to a second main shaft (24) for controlling its rotation. The first main shaft (21) and the second main shaft (22) are arranged in parallel. The rotor processing mechanism (3) includes: The mounting platform (31) is mounted on the frame (1) via a linear guide rail and can be driven to reciprocate along a direction parallel to the axes of the first spindle (21) and the second spindle (22); the control component (32) is used to control the movement of the mounting platform (31); the first forming tool (331), the second forming tool (332) and the third forming tool (333) are fixedly mounted side by side on the mounting platform (31) and arranged in a direction perpendicular to the movement direction of the mounting platform (31); the cutting edge shape of the first forming tool (331), the second forming tool (332) and the third forming tool (333) is consistent with the radial cross-sectional profile of the groove between adjacent blades of the target twisted blade rotor; The drive control system is electrically connected to the first drive motor (23), the second drive motor (24) and the control component (32).

2. The processing device for twisted-blade Roots blower rotor according to claim 1, characterized in that, The second forming tool (332) is located between the first forming tool (331) and the third forming tool (333). The second forming tool (332) is connected to a transverse moving assembly (334) that controls the transverse movement along the direction perpendicular to the moving direction of the mounting platform (31).

3. The processing device for the twisted-blade Roots blower rotor according to claim 2, characterized in that, The lateral movement component (334) is a linear motor.

4. The processing device for the twisted-blade Roots blower rotor according to claim 1, characterized in that, The first forming tool (331), the second forming tool (332) and the third forming tool (333) are forming milling cutters or forming planers.

5. The processing device for a twisted-blade Roots blower rotor according to claim 1, characterized in that, Both the first drive motor (23) and the second drive motor (24) are servo motors equipped with high-precision angle encoders.

6. The processing device for twisted-blade Roots blower rotor according to claim 1, characterized in that, The control component (32) includes a third drive motor (321) and a ball screw pair (322) that is connected to the third drive motor.

7. The processing device for a twisted-blade Roots blower rotor according to claim 1, characterized in that, The drive control system is configured to control the first drive motor (23) and the second drive motor (24) to rotate synchronously at an angular velocity ω during the processing, and to synchronously control the mounting platform (31) to move axially at a linear velocity v, wherein the ratio of the linear velocity v to the angular velocity ω, v / ω, corresponds to the helix angle β of the target twisted blade rotor.

8. A method for operating the torsion vane type Roots blower rotor processing device as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Clamping and preparation: Clamp the first rotor blank on the first spindle (21) and clamp the second rotor blank on the second spindle (22); control the transverse movement assembly (334) of the second forming tool (332) to move it laterally to the first transverse position corresponding to the processing position of the first rotor blank; S2, First processing: Control the installation platform (31) to move so that the first forming tool (331) and the second forming tool (332) are axially aligned with the first rotor blank, and the third forming tool (333) is axially aligned with the second rotor blank; Control each forming tool to perform processing actions, and simultaneously control the first drive motor (23) and the second drive motor (24) to synchronously drive the rotor blank to rotate at an angular velocity ω, and control the installation platform (31) to move axially at a linear velocity v; Thus, two spiral grooves are synchronously processed on the first rotor blank, and one spiral groove is processed on the second rotor blank; S3, Switching and Indexing: Control each forming tool to stop processing and retract from the workpiece; Control the transverse component (334) to drive the second forming tool (332) to move laterally to the second transverse position corresponding to the processing position of the second rotor blank; Control the first drive motor (23) and the second drive motor (24) to synchronously drive the first spindle (21) and the second spindle (22) to rotate by a predetermined angle; S4. Second processing: Control the installation platform (31) to move so that the first forming tool (331) is axially aligned with the first rotor blank, and the second forming tool (332) and the third forming tool (333) are axially aligned with the second rotor blank; control each forming tool to perform processing actions, and at the same time repeat the workpiece rotation and platform axial movement in step S2; thereby, the last spiral groove is processed on the first rotor blank, and the remaining two spiral grooves are processed simultaneously on the second rotor blank.

9. The working method of the torsion blade type Roots blower rotor processing device according to claim 8, characterized in that, After the first machining is completed, an in-machine measurement and compensation operation is performed. That is, the actual phase of the two helical grooves machined on the first rotor blank and the one helical groove machined on the second rotor blank is measured by an independent measuring device, and the compensation value is calculated based on the deviation between the actual phase and the theoretical phase. In the switching and indexing step, the compensation value is superimposed on the predetermined angle to correct the actual indexing command.

10. The working method of the torsion blade type Roots blower rotor processing device according to claim 8, characterized in that, It also includes the following steps S5, batch processing and tool management: continuously execute steps S1 to S4 to batch process multiple pairs of twisted blade rotors, record the number of processing cycles, and when the number of processing cycles reaches a preset threshold, determine that the wear of the first forming tool (331), the second forming tool (332) and the third forming tool (333) has reached the balanced replacement standard, and replace all three with new tools at the same time.

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