Stator assembly control method and system for online automatic grouping and matching

Abstract

The invention provides an online automatic grouping and matching stator assembly control method, which comprises the following steps: S1, binding a unique identity identification code for each stator, measuring the outer diameter of the stator, and binding outer diameter measurement data with the identity identification codes; s2, calculating the inner diameter of a shell matched with the stator according to a preset interference magnitude, and dynamically dividing the stator into a plurality of size groups according to the outer diameter measurement data or the inner diameter of the shell; s3, the central control system sends a machining instruction containing the inner diameter of the shell to a shell self-adaptive machining unit; the shell self-adaptive machining unit adjusts parameters according to the instruction, and a shell inner diameter matched with the stator is machined; and S4, synchronously conveying the shell of the processed stator and the corresponding stator to an assembly station, and executing assembly after checking the matching relationship of the identity identification codes. According to the scheme provided by the invention, the contradiction between precision and cost in large-scale production can be solved.

Description

Technical Field

[0001] This application belongs to the field of motor assembly and manufacturing technology, specifically relating to a precision control method and system for assembling the stator and housing of high-performance motors such as automotive drive motors and industrial servo motors, and particularly an automatic grouping and matching assembly method and system based on online detection and real-time data interaction. Background Technology

[0002] Electric motors, especially permanent magnet synchronous motors, serve as the core power source for modern industrial equipment and new energy vehicles. Their performance, reliability, and service life largely depend on the assembly quality of key components. Among these, the interference fit assembly between the stator core and the motor housing (or frame) is crucial. This assembly not only needs to transmit electromagnetic torque and withstand complex operating loads, but also must possess excellent thermal conductivity to ensure that the heat generated by the stator windings can be efficiently dissipated to the external environment through the housing.

[0003] Currently, the stator and housing assembly processes commonly used in industrial production are mainly divided into two categories: one is thermal assembly, which involves heating the housing to expand it before inserting the stator, and then using cooling and contraction to form an interference fit; the other is press-fit assembly, which involves using a press to axially press the stator into the housing at room temperature, relying on the elastic deformation of the material to achieve an interference connection. Regardless of the process used, the final assembly quality is directly determined by the interference fit—that is, the dimensional difference between the outer diameter of the stator and the inner diameter of the housing before assembly.

[0004] However, ensuring consistency in interference fit during mass production presents a fundamental technical challenge. As machined parts, the stator outer diameter and housing inner diameter inherently possess manufacturing tolerances. Based on tolerance and fit principles, interference fit fluctuations can reach 0.09 mm. This wide range of fluctuations leads to serious quality risks: insufficient interference fit can easily cause the stator to loosen or fretting under electromagnetic force and thermal cycling, resulting in abnormal noise, insulation damage, and even motor failure; excessive interference fit, on the other hand, can cause a sharp increase in pressing force or thermal insulation temperature difference, potentially leading to interlayer short circuits in the stator silicon steel sheets, insulation failure, or plastic deformation and even cracking of the housing.

[0005] To alleviate the above contradictions, existing technologies mainly employ two approaches: Firstly, tightening component tolerances is an option. This involves significantly reducing the values ​​of Ts and Th to decrease the fluctuation range of interference. However, this means an exponential increase in the requirements for machining equipment, cutting tools, and process stability, leading to a sharp increase in production costs, a slowdown in production cycle time, and a decrease in yield. For cost-sensitive industries such as automotive, this solution is economically unsustainable.

[0006] Secondly, selective assembly (manual grouping) is employed. This involves offline inspection of all stators and housings before assembly, followed by manual grouping based on size (e.g., large, medium, small), and then pairing and assembling within each group. While this method improves fit quality to some extent, it has significant drawbacks: First, it's an offline, batch processing model requiring a large intermediate inventory to store parts from different groups, severely violating the "one-piece flow" principle of lean manufacturing, leading to high space occupancy and significant capital tied up. Second, manual sorting, recording, and pairing are inefficient and prone to human error. Third, this method doesn't fundamentally solve the problem of random matching of parts within a group; interference fit fluctuations still exist, limiting the improvement in quality consistency.

[0007] Therefore, there is an urgent need in this field for an innovative assembly method that can achieve high precision and high consistency of the stator and housing interference fit in a large-scale, fast-paced production environment while maintaining the economical manufacturing cost of parts, thereby fundamentally solving this long-standing industry problem that has plagued the manufacturing of high-performance motors. Summary of the Invention

[0008] In view of the above problems, this application provides an online automatic grouping and matching stator assembly control method to solve the above technical problems.

[0009] On the one hand, this application provides an online automatic grouping and matching stator assembly control method, which includes the following steps: Step S1: Bind a unique identification code to each stator through a stator conveying and identity binding module, and measure the outer diameter of the stator at the stator online measuring station, and bind the outer diameter measurement data with the identification code; Step S2: Upload the identification code of the stator and the outer diameter measurement data to the central control system; The central control system calculates the inner diameter of the housing that matches the stator according to a preset interference fit, and dynamically divides the stator into multiple size groups according to the outer diameter measurement data or the inner diameter of the housing; Step S3: The central control system sends a processing instruction containing the inner diameter of the housing to the housing adaptive processing unit; The housing adaptive processing unit adjusts the parameters according to the instruction and processes the inner diameter of the housing that matches the stator; Step S4: The processed stator housing and the corresponding stator are synchronously conveyed to the assembly station, and the assembly is performed after verifying the matching relationship of the identification code.

[0010] In some embodiments, in step S2, the inner diameter of the housing that matches the stator is calculated according to the formula D_h_target = D_s - δ_target, where D_h_target is the inner diameter of the housing, D_s is the outer diameter measurement data, and δ_target is the preset interference fit.

[0011] In some embodiments, in step S3, the housing adaptive machining unit is a CNC honing machine, a precision boring machine, or a precision machining tool with online dimensional compensation function.

[0012] In some embodiments, the method further includes step S5: recording and storing full-process data for quality traceability and process optimization, wherein the data includes the stator identification code, the outer diameter measurement data, the housing inner diameter, and the size group.

[0013] In some embodiments, in step S4, before assembly, the central control system reads the identification code of the stator and performs a matching verification. Assembly can only be performed after the identification code is confirmed to be correct.

[0014] In some embodiments, the outer surface of the outer frame is provided with heat dissipation fins.

[0015] On the other hand, this application provides an online automatic grouping and matching stator assembly system for implementing the above method. The system includes: a stator conveying and identity binding module, a stator online measuring station, a central control system, and a housing adaptive machining unit. The stator conveying and identity binding module is used to convey the stator and bind the identity code to each stator. The stator online measuring station is used to measure the outer diameter of the stator and output the outer diameter measurement data of the stator. The central control system is communicatively connected to the stator online measuring station and the housing adaptive machining unit, and is used to receive the outer diameter measurement data of the stator and calculate the inner diameter of the housing that matches the stator. It also dynamically divides the stator into multiple size groups according to the outer diameter measurement data or the inner diameter of the housing, and generates and issues housing machining instructions. The housing adaptive machining unit is used to receive machining instructions from the central control system and can automatically adjust machining parameters to machine a housing with a specified inner diameter.

[0016] In some embodiments, the central control system calculates the inner diameter of the housing that matches the stator according to the formula D_h_target = D_s - δ_target, where D_h_target is the inner diameter of the housing, D_s is the outer diameter measurement data, and δ_target is the preset interference fit.

[0017] In some embodiments, the housing adaptive machining unit is a CNC honing machine, a precision boring machine, or a precision machining tool with online dimensional compensation function.

[0018] In some embodiments, the central control system reads the stator's identification code, performs a matching verification, and only executes the assembly after confirming that there are no errors.

[0019] In some embodiments, the central control system is a manufacturing execution system.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the disclosure of this application. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of an online automatic grouping and matching stator assembly control method is shown.

[0023] Figure 2 A schematic diagram of measuring the stator outer diameter using an online stator measuring station is shown.

[0024] Figure 3 A schematic diagram is shown of a housing adaptive machining unit that automatically adjusts the machining parameters of the housing according to machining instructions.

[0025] Figure 4 Another schematic diagram of the online automatic grouping and matching stator assembly control method is shown.

[0026] Figure 5 A schematic diagram of an online automatic grouping and matching stator assembly system is shown. Detailed Implementation

[0027] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0028] To enable those skilled in the art to better understand the solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] In the embodiments of this application, it should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0030] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one…" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0031] In the description of the embodiments of this application, the words "example" or "for example" are used to indicate exemplification, illustration, or description. Any embodiment or design described as "example" or "for example" in the embodiments of this application is not to be construed as being more preferred or having more advantages than another embodiment or design. The use of the words "example" or "for example" is intended to present relative concepts in a clear manner.

[0032] In addition, "multiple" in the embodiments of this application refers to two or more. Therefore, "multiple" can also be understood as "at least two" in the embodiments of this application. "At least one" can be understood as one or more, such as one, two or more. For example, including at least one means including one, two or more and is not limited to which ones are included. For example, including at least one of A, B and C, then it can be A, B, C, A and B, A and C, B and C, or A and B and C.

[0033] It should be noted that in the embodiments of this application, "and / or" describes the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after it are in an "or" relationship.

[0034] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0035] This application provides an online automatic grouping and matching stator assembly control method. The method is executed on an online automatic grouping and matching stator assembly system integrating a stator conveying and identity binding module, an online stator measuring station, a central control system, and a shell adaptive machining unit. Figure 1 As shown, the method includes the following steps: Step S1: Bind a unique identification code to each stator through the stator transport and identity binding module, and measure the outer diameter of the stator at the stator online measurement station, and bind the outer diameter measurement data with the identification code.

[0036] When the stator core enters the assembly line via the conveyor line, an industrial robot uses a vacuum suction cup to pick up a Radio Frequency Identification (RFID) chip and precisely installs it into a process hole in the stator core. This RFID chip contains a globally unique identifier, serving as the stator's identification code. Simultaneously, if the stator body has a pre-engraved QR code, a nearby vision system will read the QR code information and associate the two in the central control system.

[0037] Subsequently, the stator is transferred to the stator online measurement station. This online measurement station is equipped with active air spring vibration isolators and a dedicated air conditioning system for the machine room, maintaining constant temperature and humidity. Figure 2 As shown, the stator online measurement station includes a positioning fixture 121, a measurement system, and a measurement controller. The positioning fixture 121 can employ a V-block made of 316 stainless steel and a cylinder-driven end-face positioning mechanism, achieving a repeatability accuracy of less than 5µm. The stator 123 is fixed to the end-face positioning mechanism by a V-block, ensuring repeatability measurement accuracy. The measurement system uses four laser displacement sensors 122, arranged around the outer circumference of the stator with a 90° phase difference. Each laser displacement sensor 122 scans five sections along the Z-axis of the stator, obtaining a total of 20 sections of outer diameter data. The measurement controller uses an algorithm to fit these data in real time, calculating the actual average outer diameter measurement data of the stator 123 with a measurement accuracy of ±1.5µm. This outer diameter measurement data is bound to the stator's identification code in real time and uploaded via the network.

[0038] This is the starting point of the data flow. Each stator's identification code must be uniquely identified, and its outer diameter measurement data, as a critical dimension, must be obtained accurately and quickly. Identification binding ensures a unique correspondence between data and physical entities, while online measurement replaces traditional offline sampling inspection, achieving 100% full inspection.

[0039] Step S2: Upload the stator's identification code and the outer diameter measurement data to the central control system; the central control system calculates the housing inner diameter that matches the stator according to the preset interference, and dynamically divides the stator into multiple size groups according to the outer diameter measurement data or the housing inner diameter.

[0040] The stator's identification code and its precise outer diameter measurement data are uploaded in real time to the Manufacturing Execution System (MES) of the central control system. The MES has preset key process parameters, including preset interference, such as interference δ_target set to 0.05mm, with an allowable range of [0.045mm, 0.055mm], and the initial number of groups is set to 3.

[0041] After receiving the data, the Manufacturing Execution System (MAS) makes the following decisions: a. Calculate the inner diameter of the stator housing: Calculate the inner diameter of the housing that matches the stator using the formula D_h_target = D_s - δ_target. For example, if D_s = 200.012 mm, then D_h_target = 200.012 - 0.05 = 199.962 mm, where D_h_target is the inner diameter of the housing, D_s is the measured outer diameter, and δ_target is the preset interference fit. b. Dynamic grouping: Based on the continuously flowing stator outer diameter measurement data D_s value or housing inner diameter D_h_target value, the stator is dynamically divided into multiple size groups to ensure that the stator size distribution within the group matches the inner diameter tolerance range that the housing machining unit can guarantee under that group.

[0042] MES groups data according to preset initial group boundaries: First dimension group: D_s < 200.000 mm Second size group: 200.000mm ≤ D_s ≤ 200.015mm Third size group: D_s>200.015mm In this example, the first size group can be the small outer diameter group, the second size group can be the medium outer diameter group, and the third size group can be the large outer diameter group. The outer diameter measurement data D_s = 200.012 mm, therefore the stator is classified into the second size group. This ensures that the required housing inner diameter D_h_target range for stators within the same group can be stably machined within the tolerance zone after a single adjustment by the housing machining unit. The significance of grouping is that, for all stators in the second size group, the manufacturing execution system instructs the housing machining unit to make fine adjustments within a very narrow inner diameter range (e.g., the target value is between 199.950 mm and 199.965 mm), rather than varying significantly across the entire possible tolerance zone. This improves the stability and speed of housing machining.

[0043] The Manufacturing Execution System (MES) is the brain; it receives measured data and makes decisions based on process objectives. This step involves customizing a housing for each stator according to its actual dimensions. Grouping is used to balance "absolute precision" with "machining efficiency," avoiding excessive adjustments by the housing processing unit for each stator, thereby ensuring production cycle time.

[0044] Step S3: The central control system sends a machining instruction containing the inner diameter of the housing to the housing adaptive machining unit; the housing adaptive machining unit adjusts the parameters according to the instruction and processes the inner diameter of the housing to match the stator.

[0045] like Figure 3 As shown, the manufacturing execution system sends the machining instruction 145 containing {RFID_ID, Group_B, 199.962} to the housing adaptive machining unit in real time via the OPC UA protocol. The housing adaptive machining unit can be a CNC honing machine, a precision boring machine, or a precision machining tool with online dimensional compensation. For example, when the housing adaptive machining unit is a CNC vertical honing machine 141, the honing machine's Computerized Numerical Control (CNC) system parses the instruction, automatically calls the corresponding machining program based on the inner diameter D_h_target = 199.962mm of the housing 143, and calculates the precise target position of the honing head's oilstone 142 expansion and contraction mechanism. For example, closed-loop control is formed through feedback from an internal displacement sensor, thereby machining the inner diameter of the housing 143 to 199.962mm ± 2µm.

[0046] The adaptive machining unit for the housing automatically adjusts the machining parameters according to the machining instructions to produce a precise housing inner diameter (D_h) that matches the requirements of the upstream stator group.

[0047] This step translates the manufacturing execution system's "decision-making" into physical reality. The casings are no longer pre-processed and stored in warehouses, but are instead produced "customized" based on real-time demand. This represents a shift from "push production" to "pull production."

[0048] Through the aforementioned precise "one-to-one" matching and directional assembly process, this invention fundamentally eliminates the extreme disadvantages of interference fits. It completely avoids the problems of excessive or insufficient interference caused by matching the "smallest solid stator" with the "largest solid shell" or vice versa in traditional random assembly. The actual interference after assembly is strictly controlled within an extremely small, ideal fluctuation range, with fluctuations depending solely on the micron-level precision of online measurement and adaptive machining, ensuring ultimate consistency and reliability in assembly quality.

[0049] Step S4: The processed stator housing and the corresponding stator are synchronously transported to the assembly station, and the assembly is performed after verifying the matching relationship of the identification codes.

[0050] The finished housing is transported to the final pressing station by an Automated Guided Vehicle (AGV) equipped with an RFID reader. The AGV's scheduling system is linked with the MES (Manufacturing Execution System) to ensure that the housing and the corresponding stator arrive at approximately synchronized time. At the pressing station, an Ultra High Frequency (UHF) RFID reader fixed to the tooling simultaneously reads the IDs from the RFID chips of both the stator (S001) and the housing (H001). The production line PLC queries the MES, and after the MES confirms that "S001" and "H001" are a valid matching pair specified by the system, it sends a "pressing permission" signal to the servo press. The high-precision servo press performs pressing at a constant speed and records the force-displacement curve in real time.

[0051] Before assembly, the central control system reads the stator's identification code for matching and verification, and only proceeds with the assembly after confirming that there are no errors.

[0052] This step ensures that the correct stator and the correct housing meet at the right time and in the right place. It solves the problems of chaotic logistics and mismatches in traditional group assembly and is key to achieving "one-piece flow" production.

[0053] This invention achieves true "one-piece flow" production and zero-inventory operation. It transforms the traditional "production-inventory-assembly" model into a continuous flow model of "inspection-instruction-processing-assembly". The stator and housing do not need to be pre-produced in large quantities and stored. Instead, they are processed and matched on the spot based on real-time inspection results, which greatly reduces work-in-process inventory, space occupation, and capital backlog. It is a model of lean manufacturing.

[0054] Because the stator outer diameter (D_s) and housing inner diameter (D_h) are "tailor-made" based on the same target interference (δ_target), the constant and optimal interference ensures that every motor leaving the factory has consistent fit strength, torque transmission capability, and heat conduction performance. This directly translates into lower operating noise and vibration, higher energy conversion efficiency, and longer service life, which is crucial for enhancing the market competitiveness of the entire product.

[0055] like Figure 4 As shown, the method further includes step S5: recording and storing the entire process data for quality traceability and process optimization, wherein the data includes the stator identification code, the outer diameter measurement data, the inner diameter of the housing, and the size group.

[0056] All data from this batch of assembly, including: stator ID (S001), measured diameter D_s (200.012mm), group (Group_B), housing ID (H001), target housing inner diameter D_h (199.962mm), and measured maximum pressing force (43.5kN), are stored in the central database. The MES quality monitoring module compares the pressing force of 43.5kN with the acceptable range [40kN, 50kN] and determines it to be acceptable.

[0057] Simultaneously, the system initiated closed-loop optimization. The MES continuously monitored the D_s values ​​of all stators over the past 8 hours. Statistical Process Control (SPC) charts revealed a slow upward trend of 0.008mm in the mean D_s value due to upstream lathe tool wear. Therefore, the MES automatically fine-tuned the group boundaries, for example, adjusting the upper limit of the second size group from 200.015mm to 200.023mm to maintain a balanced number of stators in each group and ensure the system's robustness to upstream fluctuations. Three months later, if a motor exhibits abnormal noise at the customer's site, scanning its housing ID immediately allows for tracing back to all assembly data, including stator dimensions and press-fit curves, providing precise evidence for fault analysis.

[0058] This step digitizes the entire production process, not only for recording, but also for optimization and traceability. It gives the system the ability to learn and continuously improve itself.

[0059] Therefore, this invention achieves full-process automation and intelligence. The entire process is data-driven and scheduled by a central control system, providing complete traceability. Furthermore, the system can utilize assembly result data as feedback to adaptively fine-tune process parameters, achieving closed-loop control and continuous optimization, enabling the production line to possess self-learning and evolutionary capabilities.

[0060] This application also provides an online automatic grouping and matching stator assembly system for implementing the above method, such as... Figure 5 As shown, the system 100 includes a stator conveying and identity binding module 110, a stator online measurement station 120, a central control system 130, and a housing adaptive processing unit 140.

[0061] The stator conveying and identification binding module 110 is used to convey stators and bind a unique identification code to each stator. The stator conveying and identification binding module 110 includes a double-speed chain conveyor, a six-axis industrial robot, an RFID chip dispensing box, and an RFID reader / writer. The six-axis industrial robot picks up a RFID chip from the dispensing box and reliably presses the RFID chip onto a designated position on the stator core. The RFID chip contains a globally unique identification code pre-written as the stator's identification code. The RFID reader / writer then reads the RFID chip's ID and completes activation, marking the stator's formal entry into the system's traceability mechanism. The stator online measuring station 120, equipped with a high-precision non-contact measurement system and a precise positioning fixture, is used for rapid and precise measurement of the stator's outer diameter. The stator online measuring station 120 can be a standalone steel structure platform, equipped with active air spring vibration isolators and a dedicated air-conditioned room to maintain constant temperature and humidity. The stator online measuring station 120 includes a positioning fixture, a measurement system, and a measurement controller. The positioning fixture can employ V-blocks made of 316 stainless steel and a cylinder-driven end-face positioning mechanism, achieving a repeatability accuracy of less than 5µm. The measurement system includes four laser displacement sensors, such as Keyence LK-H008, fixed at 90° intervals by a precision ring bracket. This bracket integrates a Z-axis servo module, which drives the sensors to perform a 5-point scan along the stator axis. The measurement controller can specifically be an industrial personal computer (PC) running dedicated measurement software, responsible for sensor control, data acquisition, filtering, and geometric fitting calculations, ultimately outputting the stator outer diameter measurement data.

[0062] Each stator must be uniquely identified by its identification code, and its outer diameter measurement data, as a critical dimension, must be obtained accurately and quickly. Identification binding ensures a unique correspondence between data and physical entities, while online measurement replaces traditional offline sampling inspection, achieving 100% full inspection.

[0063] The central control system 130 is communicatively connected to the stator online measurement station 120 and the housing adaptive machining unit 140. It receives the outer diameter measurement data of the stator and calculates the inner diameter of the housing matching the stator. Based on the outer diameter measurement data or the inner diameter of the housing, it dynamically divides the stator into multiple size groups and generates and issues housing machining instructions. Specifically, the central control system can be a Manufacturing Execution System (MES) deployed on a server, such as a Siemens S7-1500 series PLC, responsible for real-time signal interaction and logic control between lower-level devices. It also includes a Structured Query Language (SQL) database. The MES is the brain of the system; it receives measurement data, has a built-in grouping logic algorithm (as described in Embodiment 1), assigns a group to each stator according to a dynamic grouping strategy, and calculates the target housing inner diameter. It issues adaptive instructions to the housing adaptive machining unit and manages the verification process with the assembly station. Simultaneously, it performs Statistical Process Control (SPC) analysis and closed-loop optimization algorithms.

[0064] The central control system reads the stator's identification code, performs a matching verification, and only proceeds with the assembly after confirming that there are no errors.

[0065] The stator's identification code and its precise outer diameter measurement data are uploaded in real time to the Manufacturing Execution System (MES) of the central control system. The MES has preset key process parameters, including preset interference, such as interference δ_target set to 0.05mm, with an allowable range of [0.045mm, 0.055mm], and the initial number of groups is set to 3.

[0066] After receiving the data, the Manufacturing Execution System (MAS) makes the following decisions: a. Calculate the inner diameter of the stator housing: Calculate the inner diameter of the housing that matches the stator using the formula D_h_target = D_s - δ_target. For example, if D_s = 200.012 mm, then D_h_target = 200.012 - 0.05 = 199.962 mm, where D_h_target is the inner diameter of the housing, D_s is the measured outer diameter, and δ_target is the preset interference fit. b. Dynamic grouping: Based on the continuously flowing stator outer diameter measurement data D_s value or housing inner diameter D_h_target value, the stator is dynamically divided into multiple size groups to ensure that the stator size distribution within the group matches the inner diameter tolerance range that the housing machining unit can guarantee under that group.

[0067] The significance of grouping is that, for all stators in the second size group, the manufacturing execution system instructs the housing machining unit to make fine adjustments within a very narrow range of inner diameters (e.g., target values ​​between 199.950 mm and 199.965 mm), rather than varying significantly across the entire possible tolerance zone. This improves the stability and speed of housing machining.

[0068] The shell adaptive machining unit 140 is a CNC precision machining tool that receives machining instructions from the central control system 130 and can automatically adjust machining parameters to machine a shell with a specified inner diameter (D_h). The shell adaptive machining unit 140 can be a CNC honing machine, a precision boring machine, or a precision machining tool with online dimensional compensation. For example, a CNC vertical honing machine, where the honing machine's own CNC system communicates with the MES via OPC UA. The shell adaptive machining unit receives machining instructions from the MES and parses the target shell inner diameter D_h_target. The Manufacturing Execution System (MES) sends machining instructions containing {RFID_ID, Group_B, 199.962} to the housing adaptive machining order in real time via the OPC UA protocol. After machining, the CNC system parses the instructions and, based on the housing inner diameter D_h_target = 199.962mm, automatically calls the corresponding machining program and calculates the precise target position of the honing head's honing stone expansion and contraction mechanism. For example, it forms a closed-loop control through feedback from internal displacement sensors, thereby machining the housing inner diameter to 199.962mm ± 2µm. The CNC system then automatically adjusts the honing spindle speed, reciprocating speed, and, most importantly, the expansion and contraction pressure and position of the graphite honing stone. Through a process cycle of "rough honing - fine honing - finishing," it processes the housing inner diameter to perfectly match the instruction requirements. An identical RFID chip is installed on the housing flange end face and associated with the stator ID in the MES.

[0069] The system also includes an assembly unit and a quality verification unit. After verifying the compatibility between the stator and the housing, the assembly unit is used to perform the final assembly.

[0070] The system also includes a quality verification unit. After the MES / PLC confirms correct matching, the servo press executes the pressing procedure. The recorded force-displacement curves are used not only to determine whether the assembly is qualified (whether the interference fit is appropriate), but the data is also stored for quality traceability and process analysis. It is equipped with pressing or heat fitting equipment and an identification device to verify the stator-housing fit and perform the final assembly. The quality verification unit stores all process data and supports data traceability and process optimization analysis.

[0071] Specifically, the automatic grouping and matching assembly system proposed in this application is a flexible intelligent manufacturing unit that deeply integrates perception, decision-making, execution, and data analysis capabilities. Through a central control system acting as a "digital brain," it integrates previously isolated processing, testing, and assembly stations into a highly collaborative organic whole, thereby dynamically and precisely controlling the interference fit between the stator and the housing, fundamentally resolving the contradiction between precision and cost in large-scale production.

[0072] The system begins with the stator conveying and identification binding module. Here, each stator core entering the production line is automatically guided to a binding station via a conveyor. An actuator, such as a robot or a dedicated coding device, assigns it a unique identification identifier, for example, by embedding an RFID chip with a unique ID code or engraving a QR code. This step is crucial, as it establishes a physical carrier for all subsequent data flow and material tracking, ensuring that each stator has a unique, fully traceable "ID card" in the digital world from this moment on.

[0073] Once the stator has completed its identification binding, it enters the stator online measurement station, the cornerstone of the entire system's precision. This station is not a simple pass-through detection point, but a precision metrology environment equipped with high-precision positioning fixtures and a non-contact measurement system. After the stator is securely positioned, multiple laser displacement sensors or an advanced optical vision measurement system arranged around it are activated to perform rapid, full-circumference, multi-section scanning of the stator's outer circle. The massive amount of point cloud data collected is sent to a dedicated measurement controller, which uses sophisticated algorithms (such as the least squares method) to fit the actual outer diameter value (D_s) of the stator, achieving a measurement accuracy down to the micrometer level. At this moment, this precise dimensional data is bound in real time to the stator's identification code, forming a complete data packet, and uploaded in real time to the system's central control system via the industrial network.

[0074] The central control system, typically a Manufacturing Execution System (MES), is the "intelligent core" of the entire system. After receiving stator identification and dimensional information from the measuring station, it immediately calls upon internally preset process parameters (such as the target interference δ_target and its allowable range) and intelligent grouping algorithms for processing. The system first calculates the target inner diameter of the "ideal companion" shell for the current stator (D_h_target = D_s - δ_target). Next, to ensure extreme accuracy while considering production cycle time and economy, the system performs dynamic intelligent grouping. Based on the continuously flowing stator dimensional distribution, it divides them into several (e.g., 3-5) dimensional groups. This strategy allows it to avoid requiring the shell machining unit to make radical adjustments for every stator, instead enabling fine-tuning within a very narrow tolerance range for stators of similar dimensions within the same group. Finally, the central control system generates a clear machining instruction containing the target shell inner diameter and group information, and sends it to the shell adaptive machining unit in real time.

[0075] After receiving instructions from the central control system, the adaptive machining unit for housings automatically analyzes the target inner diameter value and adjusts key machining parameters accordingly, such as the honing head's oilstone expansion and contraction or the boring tool's tool compensation value. When a housing blank enters the unit, the machine tool, based on these customized instructions, processes it to achieve a precise inner diameter that perfectly matches the requirements of a specific stator or stator assembly upstream. After machining, the housing is also bound with identification information and associated with the corresponding stator ID in the system, thus completing the transformation from an "anonymous blank" to a "dedicated part."

[0076] Subsequently, the system enters the logistics synchronization and targeted assembly stage. The machined housing and the corresponding stator, whose measurements have been completed, are precisely scheduled to the final assembly station via a conveyor system (such as AGV, RGV, or synchronous conveyor belt). This process ensures that the correct stator and the correct housing meet at the correct time and place. At the assembly station, high-precision servo presses (for press-fit assembly) or induction heating equipment (for heat fitting assembly) are typically installed, and integrated with identification devices (such as RFID readers). Before assembly, the system scans the identification codes of the stator and housing again, performing a final verification with the central database to strictly prevent mismatches. Only after confirmation can the press-fit or heat fitting operation be performed. Crucially, for press-fit assembly, the force-displacement sensor integrated into the servo press records the press-fit curve throughout the process. This data serves as the "ultimate criterion" for verifying whether the interference fit is acceptable and whether there are any defects in the assembly process.

[0077] Finally, the data management and traceability system, acting as the "memory and analysis center" of the entire platform, runs through and closes the entire process. From identity binding, dimensional measurement, processing instructions, assembly curves to the final result, all key data is collected in real time and stored in the central database. This not only establishes a full-lifecycle "digital archive" for each motor leaving the factory, achieving seamless quality traceability, but also endows the system with the ability to continuously optimize. By integrating analytical tools such as SPC (Statistical Process Control), the system can monitor dimensional trends and process capabilities, and use this feedback to adjust grouping strategies or target interference, forming a complete intelligent closed loop from perception to decision-making, execution, and optimization.

[0078] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Although this application has disclosed preferred embodiments as above, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A stator assembly control method for online automatic grouping and matching, characterized in that, The method includes the following steps: Step S1: Bind a unique identification code to each stator through the stator conveying and identity binding module, and measure the outer diameter of the stator at the stator online measurement station, and bind the outer diameter measurement data with the identification code; Step S2: Upload the stator's identification code and the outer diameter measurement data to the central control system; the central control system calculates the housing inner diameter that matches the stator according to the preset interference, and dynamically divides the stator into multiple size groups according to the outer diameter measurement data or the housing inner diameter; Step S3: The central control system sends a machining instruction containing the inner diameter of the housing to the housing adaptive machining unit; the housing adaptive machining unit adjusts the parameters according to the instruction and processes the inner diameter of the housing to match the stator; Step S4: The processed stator housing and the corresponding stator are synchronously transported to the assembly station, and the assembly is performed after verifying the matching relationship of the identification code.

2. The stator assembly control method as described in claim 1, characterized in that, In step S2, the inner diameter of the housing that matches the stator is calculated according to the formula D_h_target = D_s - δ_target, where D_h_target is the inner diameter of the housing, D_s is the outer diameter measurement data, and δ_target is the preset interference fit.

3. The stator assembly control method as described in claim 1, characterized in that, In step S3, the housing adaptive machining unit is a CNC honing machine, a precision boring machine, or a precision machining tool with online dimensional compensation function.

4. The stator assembly control method as described in claim 1, characterized in that, The method further includes step S5: recording and storing the entire process data for quality traceability and process optimization, wherein the data includes the stator identification code, the outer diameter measurement data, the inner diameter of the housing, and the size group.

5. The stator assembly control method as described in claim 1, characterized in that, In step S4, before assembly, the central control system reads the identification code of the stator and performs a matching verification. Assembly can only be performed after the code is confirmed to be correct.

6. An online automatic grouping and matching stator assembly system for implementing the method of any one of claims 1-5, characterized in that, The system includes: a stator conveying and identity binding module, a stator online measurement station, a central control system, and a shell adaptive machining unit; The stator conveying and identity binding module is used to convey the stator and bind the identity code to each stator; The stator online measuring station is used to measure the outer diameter of the stator and output the outer diameter measurement data of the stator; The central control system is communicatively connected to the stator online measurement station and the housing adaptive machining unit. It is used to receive the outer diameter measurement data of the stator and calculate the inner diameter of the housing that matches the stator. It also dynamically divides the stator into multiple size groups according to the outer diameter measurement data or the inner diameter of the housing, and generates and issues housing machining instructions. The shell adaptive machining unit is used to receive machining instructions from the central control system and can automatically adjust machining parameters to machine a shell with a specified inner diameter.

7. The online automatic grouping and matching stator assembly system as described in claim 6, characterized in that, The central control system calculates the inner diameter of the housing that matches the stator according to the formula D_h_target = D_s - δ_target, where D_h_target is the inner diameter of the housing, D_s is the outer diameter measurement data, and δ_target is the preset interference fit.

8. The online automatic grouping and matching stator assembly system as described in claim 6, characterized in that, The adaptive machining unit for the housing is a CNC honing machine, a precision boring machine, or a precision machining tool with online dimensional compensation function.

9. The online automatic grouping and matching stator assembly system as described in claim 6, characterized in that, The central control system reads the stator's identification code, performs a matching verification, and only proceeds with the assembly after confirming that there are no errors.

10. The online automatic grouping and matching stator assembly system as described in claim 6, characterized in that, The central control system is a manufacturing execution system.

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