Gear pump intelligent assembly system

Abstract

The application discloses a gear pump intelligent assembling system, and relates to the technical field of assembling equipment.The gear pump intelligent assembling system comprises a rack, a part automatic detection and matching module, a collaborative robot, a shell part automatic assembling device, an end cover part automatic assembling device, an automatic locking device and a product transfer mechanism, wherein the part automatic detection and matching module comprises an automatic detection module, a workpiece information recognition module, a detection result storage module and a matching assembling module; the shell part automatic assembling device is used for assembling shell, pin, bearing and gear parts of the gear pump; the end cover part automatic assembling device is used for assembling end cover, oil seal, bearing and baffle ring parts of the gear pump; the automatic locking device is used for screw assembling of the gear pump; and the product transfer mechanism is used for transferring the parts and semi-finished products of the gear pump between the modules; and the above modules are matched to realize full-automatic assembling and improve assembling efficiency.

Description

Technical Field

[0001] This invention relates to the field of assembly equipment technology, specifically to an intelligent assembly system for gear pumps. Background Technology

[0002] A gear pump is a rotary pump that transports or pressurizes liquids by relying on the change and movement of the working volume formed between the pump cylinder and meshing gears. It consists of two gears, a pump body, and front and rear covers forming two enclosed spaces. When the gears rotate, the volume of the space on the disengaged side increases, creating a vacuum that draws in liquid. Conversely, the volume of the space on the meshing side decreases, forcing the liquid into the pipeline. The suction and discharge chambers are separated by the meshing line of the two gears. The pressure at the discharge port of a gear pump depends entirely on the resistance at the pump outlet. A gear pump mainly consists of a pump body, gears, shafts, and seals. The pump body is the main component, the gears are the core component, the shaft connects the gears and the drive mechanism, and the seals are the key components.

[0003] Gear pumps are fluid conveying devices widely used in industrial fields. Currently, most gear pumps are assembled manually. However, manual assembly is not only inefficient but also has low precision, resulting in a high defect rate and seriously affecting the production efficiency of enterprises. Although the existing technology CN110860895A - an automatic gear pump gear assembly device - discloses a frame two with a belt conveyor two mounted on the frame two, a conveyor motor mounted on the belt conveyor two and a control device connected by a signal, the belt conveyor two is used to convey a tray containing a pump casing from the workstation one. On the side of the frame two are auxiliary conveyor frames one and two for conveying the driving gear and driven gear installed in the pump casing, respectively. Conveyor belt one and conveyor belt two are respectively installed above the auxiliary conveyor frames one and two. A handling device is also installed on the side of the frame two for handling the driving gear and driven gear conveyed on conveyor belt one and conveyor belt two, the above assembly equipment can only perform simple assembly and cannot meet the needs of automation. Summary of the Invention

[0004] The purpose of this invention is to provide an intelligent assembly system for gear pumps to solve the problems mentioned in the background art. By utilizing the cooperation of the above modules, fully automated assembly can be achieved, thereby improving assembly efficiency.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an intelligent assembly system for a gear pump, comprising a frame, on which are mounted an automatic parts detection and matching module, a collaborative robot, an automatic assembly device for housing components, an automatic assembly device for end cap components, an automatic locking device, and a product transfer mechanism. The automatic parts detection and matching module includes an automated detection module, a workpiece information identification module, a detection result storage module, and a matching assembly module. The automated detection module is a measuring machine, integrated into the automated production line to achieve an automated detection process. The workpiece information identification module, based on the workpiece identity information transmitted from the automated production line... The system automatically initiates the corresponding measurement program for the workpiece; the detection result storage module is used to automatically store workpiece detection reports and other functions; the matching and assembly module performs workpiece assembly and grading based on detection data, and guides the collaborative robot's actions for handling after data background analysis; the automatic assembly device for the housing component is used for assembling the housing, pins, bearings, and gear parts of the gear pump; the automatic assembly device for the end cover component is used for assembling the end cover, oil seal, bearings, and retaining ring parts of the gear pump; the automatic locking device is used for assembling the screws of the gear pump; there are multiple product transfer mechanisms for transferring gear pump parts and semi-finished products between various modules.

[0006] To further optimize this invention, the following technical solutions may be preferred:

[0007] Preferably, the measuring machine is a coordinate measuring machine, and the collaborative robot is a six-axis collaborative robot.

[0008] Preferably, the matching assembly module measures the gear width using a coordinate measuring machine (CMM), applies statistical and decision theory, and pairs statistical data based on the principle of minimum error to obtain the most suitable gear pair for assembly. The pairing result is then fed back to the automatic control system for the next step. The matching assembly module also uses a CMM to detect the dimensional data of the inner wheel diameter and the inner wall of the housing in a batch, establishes a mathematical model to optimize and compare the dimensions, generates the optimal gear pair, and guides subsequent assembly operations. The pairing data can also be used as reference data for experimental data modeling and analysis, for simulation analysis and quality assessment.

[0009] Preferably, the automatic assembly device for housing components includes a housing feeding mechanism, a pin assembly mechanism, a bearing assembly mechanism, and a gear assembly mechanism.

[0010] Preferably, the automatic assembly device for the end cap component includes an end cap feeding mechanism, a bearing assembly and housing assembly mechanism, an oil seal assembly mechanism, and a retaining ring assembly mechanism.

[0011] Preferably, the automatic fastening device includes a screw assembly feeding mechanism, a component flipping mechanism, and a fastening mechanism. The collaborative robot moves a tray containing materials to the waiting area of ​​the fastening device. After assembly, the materials are placed on the tray in sequence and then transferred to the next workstation by the robot. The screw assembly feeding mechanism includes a vibratory feeder for placing screws and washers. During the vibratory feeder operation, the screws pass through the washers, and the screws with washers are arranged in sequence at the vibratory feeder outlet. The component flipping mechanism is installed on the product transfer mechanism. During product transfer, the flipping mechanism flips the product 180 degrees and places it into the positioning fixture. Then, it drives the fastening mechanism to the vibratory feeder to clamp the screw assembly. The screws are pre-tightened first, and after all the screws are pre-tightened, they are tightened diagonally. The fastening mechanism is equipped with a screw stripping and loose locking detection module: when a screw is missing, stripped, or loosely locked, the system will automatically pause and sound an alarm.

[0012] Preferably, the product transfer mechanism includes a movable fixture on a movable frame, the movable fixture being provided with a flipping gripper and a gripping gripper for flipping the product 180 degrees, and a drive mechanism for driving the movable fixture to move along the X, Y, and Z directions is provided on the frame corresponding to the position of the movable fixture.

[0013] Preferably, the driving mechanism includes a first guide rail arranged along the X direction, a first slide table disposed on the first guide rail, an X-direction moving cylinder disposed on the frame for driving the first slide table to move along the first guide rail, a second guide rail arranged along the Y direction on the first slide table, a second slide table disposed on the second guide rail, a Y-direction moving cylinder disposed on the frame for driving the second slide table to move along the second guide rail, a third guide rail arranged along the Z direction on the second slide table, a third slider cooperating with the third guide rail disposed on the moving fixture, and a Z-direction moving cylinder disposed on the second slide table for driving the moving fixture to move along the third guide rail.

[0014] Preferably, the locking mechanism includes a support base mounted on a frame, on which an electric screwdriver is movably mounted; a clamping component is also mounted on the support base at a position below the screwdriver, the clamping component including a support plate and a clamping plate mounted opposite each other, wherein a transverse module is mounted on the support base at a position corresponding to the clamping component, the transverse module driving the clamping component to move laterally, and a clamping cylinder is provided on the support base for driving the clamping plate to rise and fall.

[0015] Preferably, it also includes a test unit module for measuring key parameters of the gear pump, such as flow rate, pressure, voltage, and current; a data acquisition and control platform is built based on the LabVIEW platform, which can realize the acquisition of multiple parameters of the gear pump; the multiple parameters acquired by the LabVIEW platform are used as input values ​​to the trained BP neural network, and after analysis and calculation, accurate instructions are issued to the programmable controller PLC to perform offline operation. After the test is completed, the workpiece test report is automatically stored.

[0016] This invention provides an intelligent assembly system for gear pumps, which has the following advantages:

[0017] (1) Intelligent matching technology

[0018] Intelligent matching technology manages measurement data from measuring instruments via a host computer, optimizes dimensional matching according to technical requirements to achieve better fit accuracy, and sends the matching data to the production line control system in real time. The control system then categorizes and assembles the parts based on the matching data. The main research content and solutions for intelligent matching technology are as follows: ① Information interaction. The intelligent assembly and inspection line for gear pumps has many unit systems. To meet the requirements of automatic detection and intelligent screening, signal interaction with the online detection system and the production line control system is needed, along with the transmission of workpiece unloading and grading screening by the robot. The difficulty of interoperability of communication interfaces and protocols among the various unit systems needs to be addressed. ② Part information identification. Before measuring key dimensions of parts, information marking is required. Based on the workpiece identity information transmitted via the bus, the corresponding measurement program for the workpiece is automatically started, and the measurement results are stored accordingly. ③ Automated management software. Before assembling the gear pump, key dimensions of parts need to be measured and matched. Integrating the measuring machine into the automated production line enables automated detection of key dimensions of parts. Based on the part identification information transmitted via the bus, the corresponding measurement program for the workpiece is automatically initiated. After the measurement is completed, an inspection report is generated and stored. Tooling levels are assigned based on the inspection data, and the grading results are transmitted to the robot for subsequent matching. The pairing data can also be used as reference data for experimental data modeling and analysis, enabling simulation analysis and quality assessment.

[0019] (2) Smart Lock Technology

[0020] Intelligent fastening technology is used in the handling of screw connections during assembly. While existing fastening devices improve overall fastening efficiency, they don't significantly improve fastening quality. Electric screwdrivers suffer from various problems, including lack of torque feedback, floating lock, large torque control errors, easy over-tightening, and improper matching of vertical axial force and tightening speed. Gear pumps are mostly used in military applications, where the requirements for screw assembly quality are extremely stringent. The gear pump assembly process requires that the screw surface not be damaged or pinched during tightening, and that the threads and the plane of the threaded hole not be damaged. Substandard screw assembly quality can easily lead to motor loosening and oil leakage during later use, resulting in malfunctions, downtime, and serious accidents. To achieve a safe and reliable fastening process, developing a fastening technology that meets the assembly requirements of gear pumps, based on the factory's screw structure characteristics and assembly process, is crucial to the project's success. The challenges of intelligent fastening technology include tightening positioning accuracy, feedback closed loop, and pre-tightening. The intelligent locking system should have the following functions: ① higher torque accuracy, with torque accuracy within ±3%; ② meet the locking requirements of various special threaded parts; ③ abnormal handling, monitoring and alarm information; ④ realize data collection during the tightening process, including tightening torque, tightening angle, process time, and pass / fail evaluation.

[0021] (3) Intelligent zeroing technology

[0022] After assembly, the flow rate and pressure of the gear pump need to be correlated and calibrated with the motor speed to test volumetric efficiency. By adjusting the motor current and voltage to control the motor speed, the output flow rate and pressure of the gear pump at rated speed can be precisely adjusted. Currently, the zeroing process is performed manually. Zeroing accuracy is affected by the operator's skills and professionalism, and consistency cannot be guaranteed. Due to the lag in fluid flow, the output flow rate of the gear pump is typically reflected in the hydraulic system and collected by sensors only after a delay of several seconds. The inherent fluctuations of the hydraulic system result in significant errors in the collected data, requiring optimization by a data analysis system before it can be used. Attached Figure Description

[0023] Figure 1 This is the overall flowchart of the intelligent assembly system;

[0024] Figure 2 A flowchart of the automatic assembly device for housing components;

[0025] Figure 3 This is a flowchart of the automatic assembly device for end cap components.

[0026] Figure 4 This is a schematic diagram of the overall structure of the automatic locking device;

[0027] Figure 5 This is a schematic diagram of the screw assembly feeding mechanism;

[0028] Figure 6 This is a schematic diagram of the product transfer mechanism;

[0029] Figure 7 This is the front view of the locking mechanism;

[0030] Figure 8 This is a top view of the locking mechanism;

[0031] Figure 9 This is a front view of the oil seal assembly mechanism;

[0032] Figure 10 This is a top view of the oil seal assembly mechanism.

[0033] Among them, 1-frame; 2-collaborative robot; 3-screw assembly feeding mechanism; 4-product transfer mechanism; 5-part flipping mechanism; 6-locking mechanism;

[0034] 101-Clamping jaw; 102-Flipping jaw; 103-First guide rail; 104-X-direction moving cylinder; 105-First slide table; 106-Second guide rail; 107-Second slide table; 108-Y-direction moving cylinder; 109-Third guide rail; 110-Moving fixture; 111-Third slider; 112-Z-direction moving cylinder; 201-Vibrating plate; 202-Washer channel; 203-Screw channel;

[0035] 301-Support base; 302-Electric screw gun; 303-Horizontal module; 304-Clamping component; 305-Support plate; 306-Clamping plate; 307-Clamping cylinder;

[0036] 401-Misalignment plate; 402-Pick-up gripper; 403-Pressing mechanism. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0038] This invention provides a technical solution: such as Figure 1 As shown in this embodiment,

[0039] like Figure 1-10The aforementioned intelligent assembly system for a gear pump includes a frame, on which are mounted an automatic parts detection and matching module, a collaborative robot, an automatic assembly device for housing components, an automatic assembly device for end cap components, an automatic locking device, and a product transfer mechanism. The automatic parts detection and matching module includes an automated detection module, a workpiece information recognition module, a detection result storage module, and a matching assembly module. The automated detection module is a measuring machine integrated into the automated production line to achieve automated detection. The workpiece information recognition module automatically initiates the corresponding measurement program for the workpiece based on the workpiece identity information transmitted from the automated production line. The detection result storage module automatically stores workpiece detection reports. The matching assembly module performs workpiece assembly grading based on detection data and guides the collaborative robot's actions for handling after data analysis. The automatic assembly device for housing components assembles the gear pump's housing, pins, bearings, and gear parts. The automatic assembly device for end cap components assembles the gear pump's end caps, oil seals, bearings, and retaining rings. The automatic locking device assembles the gear pump's screws. Multiple product transfer mechanisms are used to transfer gear pump parts and semi-finished products between the modules.

[0040] The measuring machine is a coordinate measuring machine, and the collaborative robot is a six-axis collaborative robot.

[0041] The matching and assembly module measures the gear width using a coordinate measuring machine (CMM). Applying statistical and decision theory, it pairs statistical data based on the principle of minimum error to obtain the most suitable gear pair for assembly. The pairing result is then fed back to the automatic control system for the next step. The matching and assembly module also uses a CMM to detect the dimensional data of the inner wheel diameter and the inner wall of the housing in a batch. It establishes a mathematical model to optimize and compare the dimensions, generating the optimal gear pair and guiding subsequent assembly operations. The pairing data can also be used as reference data for experimental data modeling and analysis, enabling simulation analysis and quality assessment.

[0042] The automatic assembly device for housing components includes a housing feeding mechanism, a pin assembly mechanism, a bearing assembly mechanism, and a gear assembly mechanism. The working principle of the equipment is as follows: The operator places the housing (O-rings are pre-installed manually) on the flow line in a certain direction. The transfer mechanism places the housing in the waiting area. Then, the shifting mechanism transfers the housing to the pin assembly station. The pins are fed through the feeding mechanism and guided into the pin hole through the guide hole. The pressing mechanism then inserts the pins into the housing. Next, the shifting mechanism transfers the housing to the bearing assembly station. The bearings are fed through the feeding mechanism, and the picking mechanism removes the bearings, dips them in lubricating oil, and then presses them into the holes. Finally, the shifting mechanism transfers the housing to the gear assembly station. The robotic arm removes the gears, dips them in 4050 aviation lubricating oil, and then the grippers hold the gears and guide them through the guide hole into the bearing hole. The gears fall into the bearing hole due to their weight, and then the grippers rotate the gears to allow them to fall into the bearing. Shell Loading Mechanism: Shells are loaded onto a conveyor line, which can hold 10 shells at a time. The shells are arranged in a specific direction, and a sensor is installed at the end of the conveyor. When the sensor detects a shell, the conveyor line automatically stops. Another sensor identifies the product orientation, and then the picking mechanism drives the gripper to pick up the product and place it at the loading station. Before loading, the sealing ring needs to be pre-installed on the shell manually. Pin Assembly Mechanism: Pins are stored in a column-like manner, and then a cylinder drives a misalignment plate to move the pins into the limiting blocks. The limiting blocks position the product based on its shape, ensuring that the pin holes in the limiting blocks are coaxial with the pin holes in the shell. Then, a pressing mechanism slowly presses the pins into the shell. Bearing assembly mechanism: After the housing is transferred to the bearing assembly station, the limiting plate uses pins to limit the product. The bearing is fed through the feeding mechanism, and the picking mechanism takes out the bearing, dips it in lubricating oil, and then uses the pressing module to press the bearing into the hole. Gear assembly mechanism: The matched gears are fed through the carrier plate, 20 sets / plate. The limiting block uses pins to position the product. The robot arm drives the oiling mechanism to apply oil to the bearing hole. The gripper clamps the two gears and inserts them. The tapered hole guides the gears to prevent them from colliding with the housing wall.

[0043] The automatic assembly device for end cap components includes end cap feeding, bearing assembly and housing assembly mechanisms, oil seal assembly mechanism, and retaining ring assembly mechanism. The working principle of the automatic assembly device is as follows: the end cap is placed on the streamline in a certain direction, and the transfer mechanism places the end cap into the waiting area; then, the shifting mechanism transfers the end cap to the bearing assembly station, the oiling mechanism applies lubricating oil to the bearing holes, the bearing is fed through the feeding mechanism, the suction nozzle holds the bearing and inserts it into the guide hole, and the pressing mechanism presses the bearing into the hole; a CCD camera is used to capture and recognize characters for later matching with the housing; finally, the rotation mechanism flips the end cap. The end cap is placed 180° on the waiting platform. A robotic arm with grippers picks up the end cap and identifies the bearing hole and pin hole positions using a CCD sensor. It is then transferred to the housing position for end cap assembly (before assembly, a CCD image is taken to identify characters on the housing and matched with the end cap). A transfer mechanism moves the housing to the oil seal assembly area, where the grippers dip the oil seal in lubricating oil before inserting it into the shaft. A pressing mechanism then presses it into the end cap. The transfer mechanism then moves the housing to the retaining ring assembly area, where the grippers hold the two holes of the retaining ring, retract it, and insert it into the end cap. After assembly, a shifting mechanism moves the housing component to the conveyor line for unloading. The end caps are fed onto a conveyor line, which can hold 10 housings at a time. The end caps are arranged in a specific direction, and a sensor is installed at the streamline end. When the sensor detects an end cap, the conveyor line automatically stops. After the end cap is transferred to the bearing assembly station, the limiting plate uses pins to limit the end cap. The robotic arm drives the suction nozzle to automatically assemble the bearing. The bearing is automatically fed by a feeder. To prevent misalignment between the shaft and the bearing hole during bearing assembly, a flexible assembly unit adaptive mechanism is installed at the end of the robotic arm. This mechanism can adapt itself when the center is misaligned. Before assembling the end cap and the housing, the characters on the end cap and the housing are identified by CCD1, and then matched in the program. After the bearing is installed, the end cap is flipped by a flipping cylinder. The gripper on the robotic arm holds the end cap and identifies the positions of the bearing hole and pin hole on the end cap at CCD2. CCD1 identifies the positions of the bearing shaft and pin hole on the housing. The position and angle of the hole and shaft are adjusted by software calculation.

[0044] Oil seal assembly mechanism: The oil seal is stored in a column manner (oil seal shaft seal lip facing down), and then the cylinder drives the misalignment plate 401 to move to separate the oil seals one by one. Then the pick-up claw 402 picks up the oil seal, dips it in lubricating oil, and puts it into the guide post pre-installed on the bearing shaft. The pressing mechanism 403 then presses the oil seal into the end cover.

[0045] Retaining ring assembly mechanism: After the end cap is transferred to the retaining ring assembly station, the positioning mechanism positions the housing and end cap assembly. Then, the material feeding mechanism separates the retaining rings one by one. The shifting mechanism drives the clamping clamp to hold the two holes of the retaining ring, retracts it, and inserts it into the end cap.

[0046] The automatic fastening device includes a screw assembly feeding mechanism 3, a product transfer mechanism 4, a component flipping mechanism 5, and a fastening mechanism 6. A collaborative robot moves a tray containing materials to the waiting area of ​​the fastening equipment. After assembly, the materials are placed on the tray in sequence and then transferred to the next workstation by the robot. The screw assembly feeding mechanism includes a vibratory feeder for placing screws and washers. During the vibration process, the screws pass through the washers, and the screws with washers are arranged in sequence at the outlet of the vibratory feeder. The fastening mechanism is equipped with a screw stripping and loose lock detection module: when the screw is not properly fastened (missing lock, stripped, loose lock), the system will automatically pause and alarm.

[0047] The collaborative robots are six-axis collaborative robots, and each device can complete one thread pre-tightening and locking process. When the intelligent assembly line reaches a certain thread assembly process, the collaborative robot will move the pallet containing the materials to the waiting area of ​​the locking equipment. After the assembly is completed, the materials are placed on the pallet in sequence and then transferred to the next workstation by the robot.

[0048] The product transfer mechanism includes a movable fixture 110 mounted on a movable mounting frame. The movable fixture is equipped with flipping grippers and grasping grippers for 180-degree product rotation. A drive mechanism is mounted on the frame corresponding to the movable fixture's position to move the movable fixture along the X, Y, and Z directions. The drive mechanism includes a first guide rail 103 arranged along the X direction, a first slide 105 mounted on the first guide rail, and an X-axis moving cylinder 104 mounted on the frame to drive the first slide along the first guide rail. A second guide rail 106 is arranged along the Y direction, and a second slide table 107 is mounted on the second guide rail. A Y-axis moving cylinder 108 for driving the second slide table to move along the second guide rail is mounted on the frame. A third guide rail 109 is mounted on the second slide table along the Z direction. A third slider 111 that cooperates with the third guide rail is mounted on the moving fixture. A Z-axis moving cylinder 112 for driving the moving fixture to move along the third guide rail is mounted on the second slide table. The driving mechanism enables the rapid and accurate positioning of the flipping gripper 102 and the gripping gripper 101.

[0049] The screw assembly feeding mechanism includes a screw channel 203, a washer channel 202, a screw-waist separation structure, and a vibratory feeder 201 connected by a welded structure; the screw and washer automatic assembly device occupies a space formed by the screw channel and washer channel as a spiral with varying curvature centered on the vibratory feeder; the end of the screw channel is located directly above the end of the washer channel; the screw channel is equipped with an adjustment structure for adjusting the screw posture and a screw screening mechanism for screening screws in different states; a separation mechanism is installed on the flat washer channel; and the screw-waist separation structure is installed at the outlet of the feeding channel of the vibratory feeder; see CN112621190A - A structural form of an automatic bolt and washer assembly device.

[0050] The locking mechanism includes a support base 301 mounted on the frame, on which an electric screwdriver 302 is movably mounted; a clamping component 304 is also mounted on the support base corresponding to the position below the screwdriver, the clamping component includes a support plate 305 and a clamping plate 306 mounted opposite to each other, wherein a transverse module 303 is mounted on the support base 301 corresponding to the position of the clamping component, the transverse module drives the clamping component to move laterally; a clamping cylinder 307 is provided on the support base for driving the clamping plate to rise and fall.

[0051] It also includes a testing unit module for measuring key parameters of the gear pump, such as flow rate, pressure, voltage, and current; a data acquisition and control platform is built based on the LabVIEW platform, which can acquire multiple parameters of the gear pump; the multiple parameters acquired through the LabVIEW platform are used as input values ​​to a trained BP neural network, which, after analysis and calculation, issues accurate instructions to the programmable logic controller (PLC) to perform offline operation, and automatically stores the workpiece inspection report after the inspection is completed.

[0052] The intelligent assembly and testing line project for gear pumps has tackled key technologies such as intelligent matching technology, intelligent locking technology, intelligent flow zeroing technology, and intelligent production line control technology, solving the technical difficulties in precision assembly and testing.

[0053] (1) Research on Parts Inspection and Matching Technology

[0054] Product assembly dimension matching quality control requires accurate measurement and analysis of parts. In addition to the necessary measurement hardware and software, many specifications and necessary auxiliary tools are also required.

[0055] 1) Measuring equipment

[0056] A coordinate measuring machine (CMM) was selected for the dimensional inspection of parts. CMMs can be structurally classified into three types: gantry, bridge, and cantilever. Taking a cantilever CMM as an example, a stepless rotating DSE probe, carbon fiber extension rod, and RST sensor were used. An automatic probe changing system was employed, along with a three-point support and cross-sectional area measuring beam. All three axes utilize linear guides, ensuring high precision and long-term stability. A multi-functional operation control system with LCD display was also included, facilitating operation and easy integration. A dedicated measurement fixture was designed to accurately position and fix the parts to be measured within the measurement system, thereby reducing the difficulty of automated measurement. Sufficient edge clearance was provided to ensure the measurability of critical dimensions and prevent interference with the measuring equipment during the measurement process. The fixture structure was constructed from a special aluminum alloy with a black anodized surface treatment. The tooling and parts in contact are made of rubber. The rubber and clamp are firmly bonded and cannot fall off. The rubber is flat and tight in contact with the parts. The clamping force is no more than 10N and will not damage the surface of the parts. It ensures that the probe contacts the reference point system (RPS). The RPS system is used for the unified positioning of all individual parts and assemblies in the manufacturing, assembly, final assembly and measurement and inspection process, and ensures the same dimensional reference. The clamp is made of the same material as or close to the measuring tooling and is treated with rust prevention, corrosion prevention and black anodizing.

[0057] 2) Measurement Procedure

[0058] To achieve rapid and automated measurement of parts and improve measurement efficiency, a part measurement program needs to be developed. Before programming, sufficient documentation resources must be prepared, including functional dimensions, 3D data, measurement point planning files (PMP), and 2D drawings. After the measurement program is developed, it needs to be debugged and modified until it meets the usage requirements.

[0059] 3) Measurement environment

[0060] As a type of testing equipment, measuring devices are characterized by high precision but are easily affected by the testing environment, such as compressed air, power supply, humidity, vibration, temperature conditions, and the condition of the parts being tested. Taking temperature conditions as an example, considering objective errors, the ambient temperature can be defined as 20 ± 2°C, and measurements can be performed based on this temperature. However, it also depends on temperature variations in the measurement environment. These variations mainly include: temperature gradient changes, long-term temperature changes, short-term temperature changes, and overall ambient temperature changes. To further ensure measurement accuracy, this factor should be fully considered during environmental planning.

[0061] 4) Intelligent matching

[0062] To achieve good dimensional matching quality for the entire vehicle, the design, manufacturing, and process departments jointly determine the measurement points and define reasonable tolerances for all measurement points. Simultaneously, various mathematical and statistical tools are used to process the large amount of measurement data to ensure optimal component dimensional matching quality. A host computer manages the measurement data from the measuring instruments, optimizing and matching dimensions according to technical requirements to achieve better fit accuracy. Specifically:

[0063] ① The width error between meshing gears is ≯0.003mm, and the manufacturing error is ±0.01mm. Therefore, the maximum difference is 0.02mm. The gear width is measured by an automatic coordinate measuring machine. Statistical and decision theory is applied, and the statistical data is matched based on the principle of minimum error to obtain the most suitable gear pair for assembly. The matching result is fed back to the automatic control system for the next step.

[0064] ② The precision required for the fit between the drive wheel and the inner wall of the housing is extremely high, determining the maximum pressure the gear pump can achieve. Before assembly, an automatic coordinate measuring machine is used to measure the dimensional data of the inner wheel's major diameter and the inner wall of the housing for a batch. A mathematical model is then established to optimize and compare the dimensions, guiding subsequent assembly operations. The mating data can also serve as reference data for experimental data modeling and analysis, enabling simulation analysis and quality assessment.

[0065] Before assembling the gear pump, key dimensions of the parts need to be measured and matched. The measuring machine is integrated into the automated production line to achieve automated detection of these key dimensions. Based on the workpiece identification information transmitted via the bus, the corresponding measurement program is automatically started. After measurement, an inspection report is generated and stored. Tooling levels are assigned based on the inspection data, and the grading results are transmitted to the robot for subsequent matching. The automated management software communicates with the hardware control system, managing and allocating system tasks; managing workpiece measurement programs, automatically completing workpiece measurements based on workpiece identification information and inspection tasks; automatically analyzing and judging workpiece inspection results, generating inspection reports and data as needed; and performing real-time matching and grading calculations based on the inspection data, transmitting the grading results to the production line robot to guide subsequent matching and assembly.

[0066] This system includes:

[0067] ①: Screw assembly feeding mechanism

[0068] Screws and washers are placed in the same vibratory feeder. During vibration, the screws pass through the washers. At the feeder outlet, the screws with washers are arranged sequentially, and a staggered assembly mechanism separates the screw groups. The washers and screws move forward along channels one and two respectively, vibrating. The ends of channels one and two are located in the same vertical plane, and from top to bottom, they are the screw channel and the washer channel, respectively. The height of the washer channel remains constant, while the height of the screw channel decreases as it moves forward. This is because as the height of the screw channel decreases, the distance between the washer and screw gradually decreases. As the distance between the screw tip and the flat washer decreases from zero to the screw tip being higher than the flat washer, the washer and screw are constantly vibrating with small amplitudes. There is a certain probability that the screw will just insert into the washer; the probability of perforation is related to the frequency and amplitude of the vibration.

[0069] ②: Flipping and locking mechanism

[0070] The component flipping mechanism is installed on the product transfer mechanism. During the product transfer process, the flipping mechanism will flip the product 180 degrees and place it into the positioning fixture. Then, it will drive the locking mechanism to the vibratory plate to clamp the screw assembly. First, the screws are pre-tightened. After all four screws are pre-tightened, the screws are tightened in a diagonal manner.

[0071] To reduce costs and save space, the product transfer mechanism uses a single drive unit to achieve pulsating operation of the product. This mechanism is responsible for transferring the product between various workstations. The product is then precisely positioned at the workstation, relying on the pin holes of the product as the positioning reference to improve assembly accuracy.

[0072] The working principle of this equipment is as follows: the component is transferred from the previous process to the assembly station. The flipping mechanism flips the component 180° and fixes it on the tooling. The screw and the washer are placed in the same vibratory feeder. The screw passes through the washer during the vibratory feeder process. At the exit of the vibratory feeder, the screws with the washer are arranged in sequence. The staggered material mechanism separates the screws. Then, the electric screwdriver equipped with the screw picking mechanism removes the screw and washer. The screw tightening mechanism drives the electric screwdriver to the locking position to assemble the screw. After the assembly is completed, the material transfer mechanism places the product on the conveyor line for unloading.

[0073] Each device can complete one thread pre-tightening and locking process. When the intelligent assembly line reaches a certain thread assembly step, a collaborative robot moves a pallet containing materials to the waiting area of ​​the locking device. After assembly, the materials are placed on the pallet and transported to the next workstation by a robot. The time to complete component 1 is approximately 10-15 seconds per piece; the time to complete component 2 is approximately 10-15 seconds per piece; the equipment can support 10 hours of continuous operation per day; modular tooling design. By changing other tooling, the flexibility of the production line can be expanded.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A gear pump intelligent assembly system, characterized in that: The system includes a frame on which an automatic parts detection and matching module, a collaborative robot, an automatic assembly device for housing components, an automatic assembly device for end cap components, an automatic locking device, and a product transfer mechanism are installed. The automatic parts detection and matching module includes an automated detection module, a workpiece information recognition module, a detection result storage module, and a matching and assembly module. The automated inspection module is a measuring machine, which is integrated into the automated production line to realize the automated inspection process. The workpiece information recognition module automatically starts the corresponding measurement program for the workpiece based on the workpiece identity information transmitted from the automated production line. The test result storage module is used to automatically store the workpiece test report; The matching assembly module classifies workpieces according to inspection data, and the data background analysis guides the collaborative robot's actions for handling; the automatic assembly device for housing components is used for assembling the housing, pins, bearings, and gear parts of the gear pump; the automatic assembly device for end cover components is used for assembling the end cover, oil seal, bearings, and retaining ring parts of the gear pump; the automatic locking device is used for assembling the screws of the gear pump; there are multiple product transfer mechanisms for transferring gear pump parts and semi-finished products between modules; The matching and assembly module measures the gear width using a coordinate measuring machine, applies statistical and decision theory, and pairs statistical data based on the principle of minimum error to obtain the most suitable gear pair for assembly. The pairing result is then fed back to the automatic control system for the next step of the operation. The matching and assembly module uses a coordinate measuring machine to detect the dimensional data of the inner wheel diameter and the inner wall of the housing in a batch, establishes a mathematical model to optimize and compare the dimensions, generates the optimal gear pair, and guides the subsequent assembly operation. Paired data can also be used as reference data for experimental data modeling and analysis, and for simulation analysis and quality evaluation. The automatic fastening device includes a screw assembly feeding mechanism, a component flipping mechanism, and a fastening mechanism. The collaborative robot moves a tray containing materials to the waiting area of ​​the fastening equipment. After assembly, the materials are placed on the tray in sequence and then transported to the next workstation by the robot. The screw assembly feeding mechanism includes a vibratory feeder for placing screws and washers. During the vibratory feed, the screws pass through the washers, and the screws with washers are arranged in sequence at the outlet of the vibratory feeder. The component flipping mechanism is installed on the product transfer mechanism. During product transfer, the flipping mechanism flips the product 180° and places it into the positioning fixture. Then, it drives the fastening mechanism to the vibratory feeder to clamp the screw assembly. The screws are pre-tightened first, and after all the screws are pre-tightened, they are tightened diagonally. The fastening mechanism is equipped with a screw stripping and loose locking detection module: when a screw is missing, stripped, or loosely locked, the system will automatically pause and sound an alarm.

2. The intelligent assembly system for a gear pump according to claim 1, characterized in that: The measuring machine is a three-coordinate measuring machine, and the collaborative robot is a six-axis collaborative robot.

3. The intelligent assembly system for a gear pump according to claim 1, characterized in that: The automatic assembly device for housing components includes a housing feeding mechanism, a pin assembly mechanism, a bearing assembly mechanism, and a gear assembly mechanism.

4. The intelligent assembly system for a gear pump according to claim 1, characterized in that: The automatic assembly device for the end cap components includes an end cap feeding mechanism, a bearing assembly and housing assembly mechanism, an oil seal assembly mechanism, and a retaining ring assembly mechanism.

5. The intelligent assembly system for a gear pump according to claim 1, characterized in that: The product transfer mechanism includes a movable fixture on a movable frame. The movable fixture is equipped with a flipping gripper and a gripping gripper for flipping the product 180 degrees. The frame is equipped with a drive mechanism for driving the movable fixture to move along the X, Y and Z directions, corresponding to the position of the movable fixture.

6. The intelligent assembly system for a gear pump according to claim 5, characterized in that: The driving mechanism includes a first guide rail arranged along the X direction, a first slide table disposed on the first guide rail, an X-axis moving cylinder disposed on the frame for driving the first slide table to move along the first guide rail, a second guide rail arranged along the Y direction on the first slide table, a second slide table disposed on the second guide rail, a Y-axis moving cylinder disposed on the frame for driving the second slide table to move along the second guide rail, a third guide rail arranged along the Z direction on the second slide table, a third slider cooperating with the third guide rail disposed on the moving fixture, and a Z-axis moving cylinder disposed on the second slide table for driving the moving fixture to move along the third guide rail.

7. The intelligent assembly system for a gear pump according to claim 1, characterized in that: The locking mechanism includes a support base mounted on a frame, on which an electric screwdriver is movably mounted; a clamping component is also mounted on the support base at a position below the screwdriver, the clamping component including a support plate and a clamping plate mounted opposite each other, wherein a transverse module is mounted on the support base at a position corresponding to the clamping component, the transverse module driving the clamping component to move laterally, and a clamping cylinder is provided on the support base for driving the clamping plate to rise and fall.

8. The intelligent assembly system for a gear pump according to claim 1, characterized in that: It also includes a test unit module for measuring key parameters of the gear pump, such as flow rate, pressure, voltage, and current; a data acquisition and control platform is built based on the LabVIEW platform, which can acquire multiple parameters of the gear pump; the multiple parameters acquired through the LabVIEW platform are used as input values ​​to the trained BP neural network, and after analysis and calculation, accurate instructions are issued to the programmable logic controller (PLC) to perform offline operation. After the test is completed, the workpiece test report is automatically stored.

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