Water pump motor for water purifier and control method thereof

Abstract

The invention discloses a water pump motor for a water purifier and a control method thereof, the water pump motor for the water purifier comprises a casing, a rear cover plate and a driving plate, the rear cover plate is arranged at one end of the casing, and the driving plate is connected with the rear cover plate and located in one end of the casing; the driving board comprises a PCB, and the PCB is provided with an MCU main control circuit, a motor driving circuit, a serial port optical coupler isolation circuit and a motor operation state detection module, wherein the motor driving circuit, the serial port optical coupler isolation circuit and the motor operation state detection module are connected with the MCU main control circuit. According to the water pump motor for the water purifier and the control method of the water pump motor, the miniaturization design of the overall structure of the water purifier is met, and the waterproof effect is good. The water pump motor is subjected to customized control, the accuracy is high, the response speed is high, communication is stable, energy consumption is reduced, the applicability is high, and the operation safety of the water pump motor is improved.

Description

Technical Field

[0001] This invention relates to a water pump motor for a water purifier and its control method, belonging to the field of motor technology. Background Technology

[0002] Currently, with the development of technology and people's increasing demands for quality of life, the application of water pump flow control systems is becoming increasingly widespread in many fields. Especially in the water purifier industry, the requirements for flow control accuracy and response speed are becoming increasingly stringent. However, existing flow control systems generally suffer from the following problems:

[0003] 1. Limited control methods: Traditional flow control systems can only control the motor's operating status through simple on / off commands, and cannot adjust the motor's operating status according to the user's real-time needs, resulting in the system's inability to achieve customized flow control.

[0004] 2. Insufficient accuracy: Existing systems often cannot accurately calculate the target speed of the motor, causing the motor to operate in a suboptimal state and fail to meet the performance requirements under different working conditions.

[0005] 3. Slow response speed: Traditional flow control systems have a slow response speed and cannot adjust the motor speed in time, making it difficult for the system to adapt to changes in flow.

[0006] 4. Unstable communication: The existing system's communication method has weak anti-interference capability and is easily affected by the external environment, resulting in unstable communication and affecting system performance.

[0007] 5. High energy consumption: The motor operates at non-optimal speed for a long time, resulting in high energy consumption and low energy efficiency ratio.

[0008] 6. Limited applicability: Existing flow control systems are often designed for specific occasions, resulting in poor applicability and difficulty in meeting the needs of different application scenarios.

[0009] 7. Safety hazards: Improper speed control may lead to equipment damage or safety hazards. Summary of the Invention

[0010] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a water pump motor and its control method for water purifiers, which meets the requirements of miniaturized design of the overall structure of the water purifier and has good waterproof performance. Customized control of the water pump motor results in high precision, fast response speed, stable communication, reduced energy consumption, strong applicability, and improved operational safety of the water pump motor.

[0011] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0012] The present invention provides a water pump motor for a water purifier, which includes a housing, a rear cover plate and a drive plate. The rear cover plate is disposed at one end of the housing, and the drive plate is connected to the rear cover plate and located inside one end of the housing.

[0013] The driver board includes a PCB board, on which an MCU main control circuit, a motor drive circuit, a serial port optocoupler isolation circuit, and a motor running status detection module are provided.

[0014] The motor drive circuit is used for motor rotation control;

[0015] The serial port optocoupler isolation circuit is used for communication between the MCU main control circuit and the water purifier motherboard;

[0016] The motor operating status detection module is used to detect the operating status parameters of the motor.

[0017] Furthermore, the motor operating status detection module includes a bus voltage detection circuit, a coil current detection circuit, an overcurrent detection circuit, a temperature and humidity detection circuit, and a vibration acceleration detection circuit;

[0018] The bus voltage detection circuit is used to detect the bus voltage value;

[0019] The coil current detection circuit is used to detect the current value of the motor coil;

[0020] The overcurrent detection circuit is used to detect whether the current in the motor coil exceeds the specified value;

[0021] The temperature and humidity detection circuit is used to detect the operating temperature of the motor and the humidity inside the motor.

[0022] The vibration acceleration detection circuit is used to detect the vibration amplitude of the motor.

[0023] Furthermore, the PCB board is also provided with an auxiliary power supply circuit, which is used to supply power to the circuit modules on the PCB board.

[0024] Furthermore, the housing includes a first mounting portion and a second mounting portion, wherein a stator assembly is disposed in the first mounting portion, the rear cover is disposed at the end of the second mounting portion, and the drive plate is located in the second mounting portion.

[0025] Furthermore, a sixth groove is provided on the edge of the rear cover plate that is connected to the second mounting part, and a third O-ring is provided in the sixth groove.

[0026] Furthermore, the first mounting section is provided with a step for axial positioning of the stator assembly.

[0027] Furthermore, a wire-passing hole is provided between the first mounting part and the second mounting part, through which the coil wire end of the stator assembly passes and connects to the drive plate on the rear cover.

[0028] Furthermore, a wire harness is connected to the PCB board, and a wire clamp is provided on the wire harness. The end of the second mounting part is provided with a notch for mounting the wire clamp.

[0029] Furthermore, the notch is provided with a first sealing surface, a second sealing surface and a third sealing surface, and the wire clamp is provided with a first groove that fits with the first sealing surface, a second groove that fits with the second sealing surface and a third groove that fits with the third sealing surface.

[0030] Furthermore, the wall surface of the notch is provided with a plurality of first labyrinth grooves and first labyrinth teeth, the first labyrinth teeth being located between two first labyrinth grooves; the wall surface of the clamp that mates with the notch is provided with a plurality of second labyrinth grooves and second labyrinth teeth, the second labyrinth teeth being located between two second labyrinth grooves; the wall surface of the rear cover that mates with the notch is provided with a plurality of third labyrinth grooves and third labyrinth teeth, the third labyrinth teeth being located between two third labyrinth grooves.

[0031] Furthermore, it also includes a front end cover, which is disposed at the end of the first mounting part, and a first bearing chamber is disposed at the center of the front end cover; a fourth groove is disposed at the connection between the front end cover and the first mounting part, and a first O-ring is disposed in the fourth groove; a through hole is disposed at the center of the front end cover, and a fifth groove is disposed on the outside of the through hole, and a second O-ring is disposed in the fifth groove.

[0032] Furthermore, a second bearing chamber is provided at the bottom of the first mounting part.

[0033] Furthermore, it also includes a rotor assembly, which includes a rotor shaft and a rotor core. The outer wall of the rotor shaft is provided with ribs, and the ribs on the outer circle of the rotor shaft are interference-fitted with the center hole of the rotor core. The rotor core is located inside the stator assembly. One end of the rotor shaft extends out from the through hole of the front end cover and is rotatably connected to the first bearing chamber of the front end cover. The outer wall of one end of the rotor shaft is interference-fitted with the inner ring of the second O-ring seal, and the other end of the rotor shaft is rotatably connected to the second bearing chamber of the first mounting part.

[0034] Furthermore, several elongated holes are provided around the central hole of the rotor core.

[0035] Another aspect of the present invention provides a control method for a water pump motor in a water purifier, comprising the following steps:

[0036] Step S1: The water purifier motherboard converts the user's instructions into motor start instructions and motor target speed parameters. The water purifier motherboard communicates with the MCU main control circuit of the driver board through the serial port optocoupler isolation circuit.

[0037] Step S2: The MCU main control circuit parses and processes the instructions and parameters from the water purifier motherboard module, and calculates the target speed value of the motor.

[0038] Step S3: Based on the performance parameters of the water pump and the fitting of measured data, the MCU main control circuit calculates the target speed value of the motor.

[0039] Step S4: The MCU main control circuit generates a motor speed control signal based on the target motor speed value and sends the motor speed control signal to the motor drive circuit.

[0040] Step S5: The motor drive circuit receives and processes the motor speed control signal to control the motor speed.

[0041] Step S7: The MCU main control circuit detects the motor's operating status parameters through the motor operating status detection module. If an abnormality occurs during motor operation, the MCU main control circuit sends the corresponding fault code to the water purifier main board through the serial port optocoupler isolation circuit. The water purifier main board module then takes appropriate action based on the fault type.

[0042] Furthermore, in step S2, the formula for calculating the target speed value n of the motor is as follows:

[0043] n = 551.05 + 97.57Q + 316.3P;

[0044] Where Q is the flow rate of the water pump and P is the outlet pressure of the water pump.

[0045] By adopting the above technical solution, this invention integrates a brushless motor drive board within the motor, resulting in a compact structure, convenient installation, and miniaturization of the overall water purifier structure. Sealing structures are added at the connections between the rear cover, the front cover and the housing, and the rotor assembly and the front cover, ensuring the motor is waterproof when installed in the water purifier. The wire clamp structure on the motor harness has been improved, achieving both waterproofing and the ability to withstand external pulling without damage. The water pump motor control method of this invention calculates the target speed of the water pump motor to meet flow requirements by fitting measured water pump outlet pressure, flow rate, and pump speed into an approximate linear formula. This method offers advantages such as accurate calculation, high efficiency, stability and reliability, energy saving, wide applicability, and high safety. Attached Figure Description

[0046] Figure 1 This is an exploded view of a water pump motor for a water purifier according to the present invention;

[0047] Figure 2 This is a schematic diagram of the internal structure of a water pump motor for a water purifier according to the present invention;

[0048] Figure 3 This is a top view of the housing of the present invention;

[0049] Figure 4 for Figure 3 A sectional view;

[0050] Figure 5 This is a front view of the notch in the present invention;

[0051] Figure 6 for Figure 5 Top view;

[0052] Figure 7 This is a schematic diagram of the front cover of the present invention;

[0053] Figure 8 This is a schematic diagram of the internal structure of the front cover of the present invention;

[0054] Figure 9 This is a schematic diagram of the rotor assembly of the present invention;

[0055] Figure 10 This is a schematic diagram of the unconnected wire harness, wire clamp, and housing in Embodiment 1 of the present invention.

[0056] Figure 11 This is a schematic diagram of the structure after the wire harness, wire clamp, and housing are connected according to Embodiment 1 of the present invention;

[0057] Figure 12 for Figure 11 Side view;

[0058] Figure 13 This is a circuit block diagram of the driver board of the present invention;

[0059] Figure 14 This is a schematic diagram of the electrical layout of the driver board of the present invention;

[0060] Figure 15 This is a circuit schematic diagram of the MCU main control circuit of the present invention;

[0061] Figure 16 This is a circuit diagram of the serial port optocoupler isolation circuit of the present invention;

[0062] Figure 17 This is a circuit diagram of the motor drive circuit of the present invention;

[0063] Figure 18 This is a circuit diagram of the auxiliary power supply circuit of the present invention;

[0064] Figure 19 This is a circuit diagram of the overcurrent detection circuit of the present invention;

[0065] Figure 20 This is a circuit diagram of the bus voltage detection circuit of the present invention;

[0066] Figure 21 This is a circuit diagram of the coil current detection circuit of the present invention;

[0067] Figure 22 This is a fitting curve of the target speed value of the motor of the present invention.

[0068] Figure 23 This is a schematic diagram of the structure after the wire harness, wire clamp, and housing are connected according to Embodiment 2 of the present invention;

[0069] Figure 24 for Figure 23 Enlarged view of part A;

[0070] Figure 25 This is a schematic diagram of the notch structure in Embodiment 2 of the present invention;

[0071] Figure 26 This is a schematic diagram of the wire clamp according to Embodiment 2 of the present invention;

[0072] Figure 27 for Figure 26 Enlarged view of part B;

[0073] Figure 28 This is a schematic diagram of the structure of the rear cover plate according to Embodiment 2 of the present invention;

[0074] Figure 29 for Figure 28 Enlarged view of part C. Detailed Implementation

[0075] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0076] Example 1

[0077] like Figure 1 , 2 As shown, this embodiment provides a water pump motor for a water purifier, which includes a housing 1, a rear cover plate 2, a drive plate 3, a front cover 5, a stator assembly 4, and a rotor assembly 6. Figure 1As shown, the housing 1 in this embodiment includes a first mounting portion 11 and a second mounting portion 12. Screw holes are provided around the rear cover plate 2, and screws pass through these holes to fix the rear cover plate 2 to one end of the second mounting portion 12. The drive plate 3 is located inside the second mounting portion 12 and connected to the rear cover plate 2. Screw holes are provided around the front cover 5, and screws pass through these holes to fix the front cover 5 to one end of the first mounting portion 11 of the housing 1. The stator assembly 4 is installed inside the first mounting portion 11, and the rotor assembly 6 is located inside the stator assembly 4. Both ends of the rotor assembly 6 are rotatably connected to the front cover 5 and the other end of the first mounting portion 11, respectively.

[0078] like Figure 3 , 4 As shown, the housing 1 in this embodiment is preferably made of die-cast aluminum, which is beneficial for motor heat dissipation. Threaded holes are also provided at both ends of the housing 1 for fixing the front cover 5 and the rear cover 2. The threaded hole located in the first mounting part 11 is used to fix the front cover 5, and the threaded hole located in the second mounting part 12 is used to fix the rear cover 2.

[0079] like Figure 2 As shown, in this embodiment, the edge of the rear cover plate 2 connected to the second mounting part 12 is provided with a sixth groove 21, and a third O-ring 211 is provided in the sixth groove 21. The design of the sealing ring can prevent water or water vapor from entering the motor from the mounting contact surface, so that the motor can meet the waterproof requirements after being installed in the water purifier.

[0080] like Figure 2 , 11 As shown in Figures 12 and 14, the rear cover plate 2 of this embodiment has two threaded holes. Screws are passed through the two mounting holes 30111 on the drive plate 3 and connected to the threaded holes on the rear cover plate 2, thus fixing the drive plate 3 to the rear cover plate 2. This embodiment integrates the drive plate 3 within the housing 1. Compared to a separate design where the motor body and drive plate 3 are separate, this design is more compact, easier to install, and facilitates miniaturization of the overall water purifier structure.

[0081] Since the drive board 3 also houses the IPM integrated power module 305, a thermal pad 7 is installed between the IPM integrated power module 305 and the rear cover plate 2. The thermal pad 7 is an insulating and thermally conductive medium material synthesized through a special process using silicone as the base material and adding various auxiliary materials such as metal oxides. The hardness of the thermal pad 7 is preferably in the Shore hardness range of 15 to 45. The thickness of the thermal pad 7 is greater than the distance between the IPM integrated power module 305 and the rear cover plate 2. The heat generated by the IPM power module is conducted to the rear cover plate 2 through the thermal pad 7. Because the IPM integrated power module 305 on the drive board 3 generates a large amount of heat during motor operation, if it is not dissipated in time, the integrated power module 305 will fail due to overheating. This design does not require an additional heat sink for the integrated power module 305; simply adding the thermal pad 7 to the IPM integrated power module 305 and then fixing the drive board 3 to the rear cover plate 2 of the motor with screws is sufficient for heat dissipation. Since the stator assembly 4 is installed into the housing 1 using a heat-shrink process, the stator core 41 fits tightly against the inner wall of the housing 1, which is conducive to heat conduction. This allows the heat generated by the motor stator coil and stator core 41 to be conducted to the housing 1, achieving the effect of heat dissipation.

[0082] like Figure 10 , 11 As shown in Figure 12, in this embodiment, a wire harness 311 is connected to the drive board 3, and a wire clip 312 is provided on the wire harness 311. A notch 121 for mounting the wire clip 312 is provided at the end of the second mounting portion 12. The wire clip 312 on the wire harness 311 is integrally injection molded with the wire harness 311. The wire clip 312 is installed in the notch 121 at one end of the second mounting portion 12 of the housing 1. The preferred material for the wire clip 312 is PVC, and the Shore hardness of the material is in the range of 15 to 45. Figure 1 As shown, in this embodiment, the notch 121 is provided with a first sealing surface 1211, a second sealing surface 1212, and a third sealing surface 1213. The wire clamp 312 is provided with a first groove 3121 that fits with the first sealing surface 1211, a second groove 3122 that fits with the second sealing surface 1212, and a third groove 3123 that fits with the third sealing surface 1213. Wherein, as... Figure 10 As shown, the distance L1 between the bottom surface of the first groove 3121 and the bottom surface of the second groove 3122 of the wire clamp 312 is greater than the distance L2 between the first sealing surface 1211 and the second sealing surface 1212 of the housing 1, that is, L1>L2.

[0083] The wire clamp 312 design on the motor wiring harness 311 not only meets the requirements for waterproofing, but also has the ability to withstand external pulling without damage. Compared with the traditional injection-molded wire clamp solution, this design solution does not require the use of fastening screws or silicone to achieve the waterproof effect. Compared with the traditional solution of using a dedicated waterproof cable connector, this design solution is low in cost and compact in structure.

[0084] like Figure 1 , 2 As shown, in this embodiment, the stator assembly 4 is installed inside the first mounting portion 11 of the housing 1, and the first mounting portion 11 is provided with a step 112 for axial positioning of the stator assembly 4. Figure 1 As shown, the stator assembly 4 in this embodiment includes a stator core 41, coil frames mounted at both ends of the stator core 41, and coils wound on the coil frames and the pole teeth of the stator core 41. The stator assembly 4 is installed into the housing 1 using a heat-fitting process. The heat-fitting process is as follows: the housing 1 is first heated to approximately 220°C, increasing the inner diameter of the first mounting portion 11 of the housing 1; then the stator assembly 4 is installed into the housing 1; after the housing 1 cools, the inner diameter of the first mounting portion 11 decreases, resulting in an interference fit between the housing 1 and the outer diameter of the stator core 41 of the stator assembly 4. Figure 1 As shown, a wire hole 13 is provided between the first mounting part 11 and the second mounting part 12 in this embodiment. The coil wire end of the stator assembly 4 passes through the wire hole 13 and is connected to the drive plate 3 on the rear cover plate 2.

[0085] like Figure 7 , 8 As shown, in this embodiment, a first bearing chamber 51 is provided at the center of the front cover 5, and a fourth groove 52 is provided at the connection between the front cover 5 and the first mounting part 11. A first O-ring seal 53 is provided in the fourth groove 52. A through hole 54 is provided at the center of the front cover 5, and a fifth groove 55 is provided on the outside of the through hole 54. A second O-ring seal 56 is provided in the fifth groove 55. Figure 1 As shown, a second bearing chamber 111 is provided at the bottom of the first mounting part 11 in this embodiment.

[0086] like Figure 9 As shown, the rotor assembly 6 in this embodiment includes a rotor shaft 61 and a rotor core 62. The outer wall of the rotor shaft 61 is provided with a raised rib 611, which is interference-fitted with the center hole of the rotor core 62. The rotor core 62 is located inside the stator assembly 4. This interference-fit installation scheme, where the raised rib 611 on the outer circle of the rotor shaft 61 is interference-fitted with the center hole of the rotor core 62, ensures a firm and reliable fit. Compared to the traditional keyway connection scheme between the rotor shaft 61 and the core, it eliminates the need for machining keyways on the shaft and installing raised keys, simplifying processing and reducing costs.

[0087] like Figure 1 , 2As shown in Figure 9, bearings 63 are installed at both ends of the rotor shaft 61, and the bearings 63 at both ends are installed in the first bearing chamber 51 and the second bearing chamber 111. One end of the rotor shaft 61 extends out of the through hole 54 of the front end cover 5 and is rotatably connected to the first bearing chamber 51 of the front end cover 5. The other end of the rotor shaft 61 is rotatably connected to the second bearing chamber 111 of the first mounting part 11. A groove 612 is also provided at one end of the rotor shaft 61 to mate with the water pump shaft of the water purifier. The outer wall of one end of the rotor shaft 61 is press-fitted with the inner ring of the second O-ring seal 56. The first O-ring seal 53 is provided at the connection between the front end cover 5 and the first mounting part 11 of the housing 1, and the second O-ring seal 56 is provided at the connection between the rotor shaft 61 and the through hole 54 of the front end cover 5. This design can prevent water or water vapor from entering the motor from these two connection points, so that the motor meets the waterproof requirements after being installed in the water purifier.

[0088] like Figure 9 As shown, in this embodiment, the rotor core 62 has several elongated holes 621 around its central hole. These holes facilitate the installation of balancing mud, preventing it from falling off due to excessive centrifugal force when the motor is running at high speed. After the rotor shaft 61, rotor core 62, magnet 64, and bearing 63 are assembled into the rotor assembly 6, the rotor assembly 6 needs to be tested and the imbalance corrected on a dynamic balancing machine. This can be done in the following ways:

[0089] 1. If the unbalance is less than the specified value, it is not necessary to fill the elongated hole 621 with balancing mud. All elongated holes 621 can be used for heat dissipation.

[0090] 2. If the imbalance is slightly greater than the specified value, then you only need to fill a small amount of balancing mud into one or two of the elongated holes 621 at the corresponding positions indicated by the dynamic balancing machine. The balancing mud will not completely block the elongated holes 621, and all the elongated holes 621 can be used for heat dissipation.

[0091] 3. If the imbalance exceeds the specified value by a large margin, it is necessary to fill more elongated holes 621 with balancing mud according to the corresponding position indicated by the dynamic balancing machine. The maximum amount should not exceed half of the total number of elongated holes 621. The balancing mud does not completely block the elongated holes 621, and all elongated holes 621 can be used for heat dissipation.

[0092] like Figure 13 , 14 As shown, the driver board 3 in this embodiment includes a PCB board 301. The PCB board 301 is provided with an MCU main control circuit 302 and a motor drive circuit 303, a serial port optocoupler isolation circuit 304, a motor running status detection module, and an auxiliary power supply circuit 310 connected to the MCU main control circuit 302.

[0093] like Figure 15As shown, the MCU main control circuit 302 in this embodiment includes an MCU chip, a 3.3V power supply port connected to an auxiliary power supply, a first I / O port to a fourteenth I / O port connected to the MCU chip, and program debugging and programming ports SWCLK and SWDIO. The preferred MCU chip model in this embodiment is STM32F030K6T6.

[0094] The first I / O port is connected to the bus voltage detection signal output terminal of the bus voltage detection circuit; the second I / O port is connected to the temperature signal port AD2_VTS of the IPM integrated power module 305; the third I / O port is connected to AD3_IU of the coil current detection circuit 306; the fourth I / O port is connected to AD4_IV of the coil current detection circuit 306; the fifth I / O port is connected to AD5_IW of the coil current detection circuit 306; the sixth I / O port is connected to the BK port of the overcurrent detection circuit; and the seventh I / O port is connected to the signal input port UL of the motor drive circuit 303. The eighth I / O port is connected to the signal input port VL of the motor drive circuit 303, the ninth I / O port is connected to the signal input port WL of the motor drive circuit 303, the tenth I / O port is connected to the signal input port UH of the motor drive circuit 303, the eleventh I / O port is connected to the signal input port VH of the motor drive circuit 303, the twelfth I / O port is connected to the signal input port WH of the motor drive circuit 303, the thirteenth I / O port is connected to the TXD port of the serial port optocoupler isolation circuit 304, and the fourteenth I / O port is connected to the RXD port of the serial port optocoupler isolation circuit 304.

[0095] like Figure 17 As shown, the motor drive circuit 303 in this embodiment is used to control the rotation of the motor. Under the control of the MCU main control circuit 302, it will turn the motor coil on or off. The motor drive circuit 303 includes an IPM integrated power module 305, resistors R7 and R8, current sampling resistors RS1, RS2, and RS3, capacitors C7, C8, C9, C10, C11, C12, and C13, signal input ports UH, UL, VH, VL, WH, and WL, current sampling signal terminals RS1_1, RS1_2, RS2_1, RS2_2, RS3_1, and RS3_2, and the temperature signal port AD2_VTS, port U, port V, and port W of the IPM integrated power module 305. The preferred specification for the IPM integrated power module 305 is CS5755AT.

[0096] Specifically, signal input port UH is connected to the tenth I / O port of MCU main control circuit 302, signal input port UH is connected to the seventh I / O port of MCU main control circuit 302, signal input port VH is connected to the eleventh I / O port of MCU main control circuit 302, signal input port VL is connected to the eighth I / O port of MCU main control circuit 302, signal input port WH is connected to the twelfth I / O port of MCU main control circuit 302, signal input port WL is connected to the ninth I / O port of MCU main control circuit 302, and the temperature signal port AD2_VTS of IPM integrated power module 305 is connected to the second I / O port of MCU main control circuit 302; port U is connected to pad U on PCB, port V is connected to pad V on PCB, and port W is connected to pad W on PCB.

[0097] The MCU main control circuit 302 uses signal input ports UH, UL, VH, VL, WH, and WL. Through the signal processing circuit within the integrated power module, it regulates the current and voltage to meet the control requirements of the brushless DC motor. In this embodiment, the values ​​of the current sampling resistors RS1, RS2, and RS3 are 0.1Ω. The advantages of using an integrated power module are as follows:

[0098] 1. High integration: Integrated power modules combine multiple circuit components into one module, resulting in higher integration. Compared to power transistors that use discrete components, integrated power modules can reduce the number and size of components on the circuit board, simplifying the design.

[0099] 2. Improved Efficiency: Integrated power modules typically have high conversion efficiency, reducing energy loss during power conversion. Compared to discrete power transistors, using integrated power modules can improve the system's energy utilization efficiency.

[0100] 3. Protection Functions: The integrated power module features overcurrent protection, overheat protection, and short-circuit protection. These protection mechanisms effectively protect the motor and other system components, increasing the system's reliability and stability.

[0101] 4. Reduced costs: Simplified design, fewer components, and higher energy efficiency can reduce the overall cost of the system.

[0102] like Figure 16As shown, the serial port optocoupler isolation circuit 304 in this embodiment is used for communication between the MCU main control circuit 302 and the water purifier motherboard. It can protect the communication interface between the water purifier motherboard module and the MCU main control circuit 302 from damage and improve the reliability of serial communication. The serial port optocoupler isolation circuit 304 consists of optocouplers U4 and U5, and resistors R30, R31, R33, and R35. The negative terminal TXD port of optocoupler U4 is connected to the thirteenth I / O port of the MCU, and the collector of optocoupler U4 is connected to the RX pad 3018 of the serial port receiving port on the PCB board 301. The negative terminal of optocoupler U5 is connected to the TX pad 3019 of the serial port transmitting port on the PCB board 301, and the collector RXD port of optocoupler U5 is connected to the fourteenth I / O port of the MCU main control circuit 302. One end of resistor R33 is connected to the collector of U4, and the other end is connected to the SVCC pad 3020.

[0103] Data sent and received by the water purifier motherboard passes through pads connected to wiring harness 311, including serial port signal ground SGND pad 3017, serial port receive port RX pad 3018, serial port transmit port TX pad 3019, and serial port power SVCC pad 3020. Then, data exchange occurs between the serial port optocoupler isolation circuit 304 and the RXD and TXD ports of the MCU main control circuit 302. The advantages of using the serial port optocoupler isolation circuit 304 are as follows:

[0104] 1. Electrical Isolation: The serial port optocoupler isolation circuit 304 can achieve electrical isolation between input and output. Through optocoupler isolation, the electrical connection between the RX and TX signals of the water purifier main board module and the RXD and TXD signals of the MCU main control circuit 302 of the motor is isolated, thereby effectively preventing the influence of external interference, electromagnetic interference and electrical noise.

[0105] 2. Protection function: The optocoupler isolation circuit can provide a certain protection function. When an electrical fault or overvoltage occurs at the RX and TX signal terminals of the water purifier main block, the isolation circuit can limit these electrical problems to the water purifier main block module, thereby protecting the motor drive board 3 circuit related to the RXD and TXD signals of the MCU main control circuit 302 from damage.

[0106] 3. Compatibility: The serial port optocoupler isolation circuit 304 can realize signal conversion and matching between different levels and electrical characteristics, thereby improving system compatibility. For example, the peak voltage of the RX and TX signals of the water purifier motherboard module does not need to be 3.3V; it can be 5V or higher without affecting the normal communication between the water purifier motherboard module and the MCU main control circuit 302 of the motor drive board 3.

[0107] 4. Anti-interference capability: Due to the electrical isolation characteristics of the optocoupler isolation circuit, it can provide good anti-interference capability. In complex electromagnetic environments or in the presence of interference sources, the isolation circuit can effectively reduce the impact of these interferences on the motor drive board 3, providing more reliable signal transmission.

[0108] like Figure 18 As shown, the auxiliary power supply circuit 310 in this embodiment is used to power the circuit modules on the PCB board 301, converting the power supplied by the water purifier into the power required by the PCB board 301. It consists of a low-dropout regulator integrated circuit chip U1, capacitors C15, C17, C16, C18, resistors R24, R24-2, diode D1, and an auxiliary power supply output terminal +3V3. In this embodiment, the low-dropout regulator integrated circuit chip U1 is preferably LM1117.

[0109] like Figure 13 As shown, the motor operating status detection module in this embodiment is used to detect the operating status parameters of the motor. The motor operating status detection module includes a bus voltage detection circuit, a coil current detection circuit 306, an overcurrent detection circuit 307, a temperature and humidity detection circuit 308, and a vibration acceleration detection circuit 309.

[0110] like Figure 20 As shown, the bus voltage detection circuit in this embodiment is used to detect the bus voltage value. The bus voltage detection circuit consists of resistors R11, R10, R27, R23, R9, R28, diode D5, capacitor C14, and a bus voltage detection signal output terminal. The bus voltage detection signal output terminal is connected to the first I / O port of the MCU chip. The detection voltage range of the first I / O port of the MCU main control circuit 302 is 0–3.3V. The voltage divider circuit composed of resistors R11, R10, R27, R23, R9, and R28 reduces the bus voltage (approximately 311V) and outputs it to the bus voltage detection signal output terminal.

[0111] The bus voltage detection circuit converts the DC power generated by the rectifier circuit into a low-voltage signal that can be detected by the MCU main control circuit 302 and transmits it to the MCU main control circuit 302. In this embodiment, the voltage at the DC VDC terminal on the PCB board 301 is approximately 311V. The values ​​of R11, R10, R27, and R23 are 300KΩ, the value of R9 is 8.2KΩ, and the value of R28 is 1KΩ. The voltage is converted to the range of 0-3.3V through a voltage divider circuit so that the MCU main control circuit 302 can detect it. The purpose of setting up the bus voltage detection circuit is to generate an alarm when the mains power is too low or too high. The system stops working when the mains power is too low or too high, thus protecting the system.

[0112] like Figure 21As shown, the coil current detection circuit 306 in this embodiment is used to detect the current value of the motor coil. The coil current detection circuit 306 includes operational amplifiers U2A, U2B, U2C, U2D, resistors R21, R22, R41~R45, R50~R59, capacitors C19, C37, C38, C20, C22, C23, C25, C26, C28, U-phase current signal input terminals RS1_1, RS1_2, V-phase current signal input terminals RS2_1, RS2_2, W-phase current signal input terminals RS3_1, and RS3_2.

[0113] Specifically, the U-phase current signal input terminals RS1_1 and RS1_2 are connected to the current sampling signal terminals RS1_1 and RS1_2 of the motor drive circuit 303, respectively; the V-phase current signal input terminals RS2_1 and RS2_2 are connected to the current sampling signal terminals RS2_1 and RS2_2 of the motor drive circuit 303, respectively; and the W-phase current signal input terminals RS3_1 and RS3_2 are connected to the current sampling signal terminals RS3_1 and RS3_2 of the motor drive circuit 303, respectively. The AD3_IU port is connected to the third I / O port of the MCU main control circuit 302, the AD4_IV port is connected to the fourth I / O port of the MCU main control circuit 302, and the AD5_IW port is connected to the fifth I / O port of the MCU main control circuit 302.

[0114] In the voltage follower circuit composed of operational amplifier U2A, the output voltage of operational amplifier U2A is 1.65V, providing a bias voltage to the non-inverting inputs of operational amplifiers U2B, U2C, and U2D. This is to ensure that the voltage range after signal amplification is within the AD voltage range of the MCU control circuit. The voltages corresponding to AD3_IU, AD4_IV, and AD5_IW at the output ports of operational amplifiers U2B, U2C, and U2D are connected to the I / O ports of the MCU main control circuit 302. To facilitate the calculation of the amplification factors of operational amplifiers U2B, U2C, and U2D and to reduce the variety of resistor specifications, the resistance values ​​of resistors R41, R43, R50, R51, R55, and R56 are equal, and the resistance values ​​of resistors R42, R44, R52, R53, R57, and R58 are also equal. The coil current detection circuit 306 has the following advantages:

[0115] 1. Ensure the accuracy of AD conversion: The bias voltage of the operational amplifier can be used to adjust the voltage range of the amplified current signal to the effective voltage range of the MCU's AD port. This ensures that the AD converter can accurately measure and process the current signal, avoiding data distortion or overflow caused by the signal exceeding the AD port voltage range.

[0116] 2. Improve measurement accuracy: By setting an appropriate bias voltage, the output signal of the current detection circuit can be more evenly distributed within the operating range of the AD converter, thereby improving the measurement accuracy and stability, helping to reduce errors and improve the reliability of the system.

[0117] 3. Adaptability to different current ranges: By adjusting the bias voltage, the current sensing circuit can adapt to measurement requirements within different current ranges. This improves the circuit's flexibility and scalability, making it suitable for motor control applications with varying power ratings.

[0118] 4. Strong anti-interference capability: Appropriately setting the bias voltage can improve the anti-interference capability of the current detection circuit. The bias voltage helps reduce the influence of external noise on the circuit, improves the signal-to-noise anti-interference ratio, and thus improves the stability and reliability of the system.

[0119] 5. Simplified design and debugging: By setting a bias voltage in the peripheral circuit, the complexity of circuit design and debugging can be simplified.

[0120] like Figure 19 As shown, the overcurrent detection circuit 307 in this embodiment is used to detect whether the current of the motor coil exceeds a specified value. The overcurrent detection circuit 307 includes comparators U3A, U3B, U3C, U3D, resistors R60, R61, R62, R63, R18, R19, R20, R25, capacitors C42, C36, C43, C31, C39, C40, C41, U-phase current signal input terminal RS1_1, V-phase current signal input terminal RS2_1, and W-phase current signal input terminal RS3_1.

[0121] Among them, the U-phase current signal input terminal RS1_1 is connected to the current sampling signal terminal RS1_1 of the motor drive circuit 303, the V-phase current signal input terminal RS2_1 is connected to the current sampling signal terminal RS2_1 of the motor drive circuit 303, the W-phase current signal input terminal RS3_1 is connected to the current sampling signal terminal RS3_1 of the motor drive circuit 303, and the port BK is connected to the sixth I / O port of the MCU main control circuit 302.

[0122] Resistors R60 and R61, along with the 3.3V voltage port, form a voltage divider circuit. The value of R60 is 9.1KΩ, and the value of R61 is 1.2KΩ. Therefore, the voltage at the non-inverting input of comparators U3A, U3B, U3C, and U3D is 3.3 × R61 / (R60 + R61) = 0.384V. This voltage value corresponds to the overcurrent threshold. When the voltage at the current sampling signal terminals RS1_1, RS2_1, and RS3_1 of the motor drive circuit 303 exceeds 0.384V, port BK changes from low to high. Upon detecting the high level at the sixth I / O port of the MCU main control circuit 302 connected to port BK, the MCU main control circuit 302 shuts down the outputs of ports U, V, and W through signal input ports UH, UL, VH, VL, WH, and WL, cutting off the motor coil current and preventing motor failure due to overload. The overcurrent detection circuit 307 has the following advantages:

[0123] 1. High-precision overcurrent detection: The overcurrent detection circuit 307 using a comparator can accurately compare the sampled current value with the set corresponding value. By setting an appropriate threshold through resistors R60 and R61, it can promptly detect situations where the motor coil currents U, V, and W exceed the set range.

[0124] 2. Fast Response Time: The comparator has a fast response speed, enabling it to quickly transmit the comparison result to the MCU main control circuit 302 for processing via port BK. This allows for timely implementation of appropriate control strategies, such as reducing the motor drive signal to prevent the current from exceeding the rated range, thereby protecting the motor and other system components.

[0125] 3. Flexibility: By setting appropriate values ​​for resistors R60 and R61, the overcurrent detection parameters can be flexibly configured according to actual needs. This allows the circuit to adapt to the requirements of different motors and application scenarios, providing more flexible and customizable overcurrent protection functions.

[0126] 4. Simplified Design: The comparator's overcurrent detection circuit 307 simplifies the overall circuit design. By using a comparator, cumbersome analog circuit design can be avoided, reducing system complexity and cost.

[0127] 5. Reliability: The overcurrent detection circuit 307 improves system reliability. By promptly detecting and responding to overcurrent conditions, damage to motors and other system components due to overload can be avoided, extending the system's lifespan.

[0128] like Figure 13 As shown, the temperature and humidity detection circuit 308 in this embodiment is used to detect the operating temperature of the motor and the humidity inside the motor.

[0129] The temperature detection circuit consists of a temperature sensor mounted on PCB board 301 and an integrated operational amplifier circuit. The temperature sensor can be an NTC thermistor. The temperature sensor monitors the motor temperature and outputs a voltage or digital signal through the integrated operational amplifier circuit. The MCU main control circuit 302 periodically reads these signals and compares them with the set temperature threshold. If the temperature exceeds the threshold, the MCU main control circuit 302 sends a warning signal to the water purifier main board through the serial port optocoupler isolation circuit 304.

[0130] The MCU main control circuit 302 reads data from the humidity detection circuit installed on the PCB board 301. The humidity sensor component in the humidity detection circuit can be either DHT11 or DHT22. The humidity sensor monitors the humidity inside the motor and outputs the humidity value through a digital signal. The MCU main control circuit 302 reads the humidity value and compares it with the safe range. If the humidity exceeds the safe range, the MCU main control circuit 302 adjusts the motor's operating state through the control module. For example, if the motor and water pump are used beyond their lifespan, the sealing rings age, and the sealing effect decreases, if water or water vapor leaks into the motor, and the humidity detection circuit on the drive board 3 detects that the humidity exceeds the safe range, the MCU main control circuit 302 closes the outputs of ports U, V, and W through signal input ports UH, UL, VH, VL, WH, and WL, cutting off the motor coil current, stopping the motor, and transmitting the shutdown fault information to the water purifier main board through the serial port optocoupler isolation circuit 304.

[0131] like Figure 1 As shown, the vibration acceleration detection circuit 309 in this embodiment is used to detect the vibration amplitude of the motor. The vibration acceleration sensor in the vibration acceleration detection circuit 309 can be an ADXL345. The acceleration sensor monitors the motor vibration and outputs vibration data via digital signals. The MCU main control circuit 302 reads this data and compares it with a preset vibration threshold. If the vibration exceeds vibration threshold one, a shutdown warning message is transmitted to the water purifier main board via the serial port optocoupler isolation circuit 304. If the vibration exceeds vibration threshold two, the MCU main control circuit 302 closes the outputs of ports U, V, and W through signal input ports UH, UL, VH, VL, WH, and WL, cutting off the motor coil current, stopping the motor, and transmitting the shutdown fault information to the water purifier main board via the serial port optocoupler isolation circuit 304. Typically, vibration threshold one can be set to a condition where the motor or water pump installation is loose and does not affect the continued use of the water purifier, while vibration threshold two can be set to a vibration value where continued operation may lead to an aggravation of the fault when the motor is malfunctioning. The vibration acceleration detection circuit 309 has the following advantages:

[0132] By integrating temperature, humidity, and vibration acceleration sensors onto the driver board 3, real-time monitoring of the motor's status is achieved, thereby improving the reliability and safety of motor operation. The water purifier's mainboard and driver board 3 communicate via serial port for fault alarms and convenient speed adjustment.

[0133] like Figure 1 As shown, the PCB board 301 in this embodiment has three pads for soldering to the motor stator coil. The three pad holes are: U pad 3011, V pad 3012, and W pad 3013. The PCB board 301 also has seven pads for soldering to the wire ends of the wire harness 311. The seven pads are: VDC pad 3014 for motor power supply, PGND pad 3015 for motor power supply ground, VCC pad 3016 for auxiliary power supply of driver board 3, SGND pad 3017 for serial port signal ground, RX pad 3018 for serial port receiver, TX pad 3019 for serial port transmitter, and SVCC pad 3020 for serial port power supply.

[0134] The motor drive circuit 303, MCU main control circuit 302, bus voltage detection circuit, auxiliary power supply circuit 310, serial port optocoupler isolation circuit 304, overcurrent detection circuit, temperature and humidity detection circuit 308, and vibration acceleration detection circuit 309 on the PCB board 301 in this embodiment are laid out as follows: Figure 14 As shown.

[0135] The auxiliary power supply circuit 310 is located in the center of the PCB board 301. This is to minimize the wiring path from the 3.3V output of the auxiliary power supply to the current to the other circuit modules, facilitate PCB routing, and reduce interference.

[0136] U pad 3011, V pad 3012, W pad 3013, and IPM integrated power module 305 are located on the edge of PCB board 301 and within the area of ​​motor drive circuit 303. This is to minimize the wiring paths from U port, V port, and W port to U pad 3011, V pad 3012, and W pad 3013, respectively, which facilitates PCB wiring and also makes it easier to solder the U, V, and W ends of the motor coil to U pad 3011, V pad 3012, and W pad 3013, respectively.

[0137] The coil current detection circuit 306 is located below and adjacent to the motor drive circuit 303. This is to minimize the wiring path from the U-phase current input signal, V-phase current input signal, and W-phase current input signal of the motor drive circuit 303 to the coil current detection circuit 306, thereby reducing interference.

[0138] The SGND pad 3017 for serial port signal ground, the RX pad 3018 for serial port receiver, the TX pad 3019 for serial port transmitter, and the SVCC pad 3020 for serial port power are positioned above and adjacent to the top of the serial port optocoupler isolation circuit 304. This is to minimize the wiring path from the SGND pad 3017 for serial port signal ground, the RX pad 3018 for serial port receiver, the TX pad 3019 for serial port transmitter, and the SVCC pad 3020 for serial port power to the serial port optocoupler isolation circuit 304, thereby reducing interference.

[0139] Example 2

[0140] like Figures 23-29 As shown, this embodiment provides another way of fitting and structure of the wire clamp 312 and the notch 121.

[0141] In this embodiment, the wall surface of the notch 121 is provided with a plurality of first labyrinth grooves 1214 and first labyrinth teeth 1215, with the first labyrinth teeth 1215 located between two first labyrinth grooves 1214; the wall surface of the wire clamp 312 that mates with the notch 121 is provided with a plurality of second labyrinth grooves 3124 and second labyrinth teeth 3125, with the second labyrinth teeth 3125 located between two second labyrinth grooves 3124; the wall surface of the rear cover plate 2 that mates with the notch 121 is provided with a plurality of third labyrinth grooves 22 and third labyrinth teeth 23, with the third labyrinth teeth 23 located between two third labyrinth grooves 22. During motor assembly, the third labyrinth tooth 23 of the rear cover plate 2 is inserted into the second labyrinth groove 3124 of the wire clamp 312, and the second labyrinth tooth 3125 of the wire clamp 312 is inserted into the third labyrinth groove 22 of the rear cover plate 2; the first labyrinth tooth 1215 of the housing 1 is inserted into the second labyrinth groove 3124 of the wire clamp 312, and the second labyrinth tooth 3125 of the wire clamp 312 is inserted into the first labyrinth groove 1214 of the housing 1.

[0142] When a gas or liquid flows from the high-pressure side to the low-pressure side under the influence of a pressure difference, it passes through the labyrinthine gaps formed by labyrinth teeth and grooves. During this process, the gas or liquid undergoes multiple throttling and expansion cycles, causing its pressure and temperature to gradually decrease. Simultaneously, the gas or liquid is subjected to friction and shearing forces as it passes through the gaps formed by the labyrinth teeth and grooves. These combined effects significantly reduce the leakage rate of the medium, thus achieving a sealing effect.

[0143] Example 3

[0144] This embodiment provides a method for controlling the speed of a water pump motor in a water purifier, which includes the following steps:

[0145] Step S1: The water purifier motherboard converts the user's instruction switch instruction or flow instruction into a motor start instruction and a motor target speed parameter. The water purifier motherboard communicates with the MCU main control circuit 302 of the driver board 3 through the serial port optocoupler isolation circuit 304.

[0146] Step S2: The MCU main control circuit 302 parses and processes the instructions and parameters from the water purifier motherboard module, and calculates the target speed value of the motor. The formula for calculating the target speed value n of the motor is as follows:

[0147] n = 551.05 + 97.57Q + 316.3P;

[0148] The target speed n of the motor is in rpm;

[0149] Q represents the flow rate of the water pump, measured in L / min.

[0150] P represents the outlet pressure of the water pump, measured in MPa.

[0151] For example: Figure 22 As shown, when the water purifier's main board module requires a flow rate of 3L / min, the formula for calculating the motor's target speed n is as follows:

[0152] n = 843.7 + 316.3 × P;

[0153] When the water purifier's main board module requires a flow rate of 5L / min, the formula for calculating the motor's target speed n is as follows:

[0154] n = 1038.9 + 316.3 × P.

[0155] If the outlet pressure P is 0.2 MPa and the mainboard module's flow rate requirement is 3 L / min, then the calculated target motor speed n is as follows:

[0156] n=843.7+316.3×0.2=907rpm;

[0157] If the outlet pressure P is 0.2 MPa and the mainboard module's flow rate requirement is 5 L / min, then the calculated result of the motor's target speed n is as follows:

[0158] n=1038.9+316.3×0.2=1102rpm.

[0159] The calculation method in this embodiment, which uses measured pump outlet pressure, flow rate, pump speed, and motor speed to fit an approximate linear formula, has the following advantages:

[0160] 1. Formulas based on measured data are more practical and reliable because they are derived from actual operation and verification.

[0161] 2. The main advantage of this solution lies in its optimized MCU program code, avoiding the storage space consumption of traditional methods. Traditional methods typically store data in the MCU's flash memory using tables, and then the MCU determines the motor's target speed by looking up the table based on the water purifier's mainboard flow requirements and the pump's outlet pressure. While effective, this method consumes considerable MCU storage space and results in lengthy code. In contrast, this solution directly determines the motor's target speed using a formula calculation, eliminating the need for extensive data storage in the MCU, thus saving storage resources and simplifying the code structure.

[0162] Step S3: Based on the performance parameters of the water pump and the fitting of measured data, the MCU main control circuit 302 calculates the target speed value of the motor.

[0163] Step S4: The MCU main control circuit 302 generates a motor speed control signal based on the target speed value of the motor and sends the motor speed control signal to the motor drive circuit 303. The signal is output from the ninth to fourteenth I / O ports of the MCU main control circuit 302 and corresponds to the signal input ports UH, UL, VH, VL, WH, and WL of the motor drive circuit 303.

[0164] Step S5: The motor drive circuit 303 receives and processes the motor speed control signal. By changing the output signal of the ninth to fourteenth I / O ports, it controls the motor speed and adjusts the motor speed to achieve flow control of the water purifier pump.

[0165] Step S7: The MCU main control circuit 302 detects the motor's operating status parameters through the motor operating status detection module. If an abnormality occurs during motor operation, such as motor stall, phase loss, overcurrent, abnormal temperature, abnormal humidity, or abnormal vibration, the MCU main control circuit 302 sends the corresponding fault code to the water purifier main board through the serial port optocoupler isolation circuit 304. The water purifier main board module then takes appropriate action based on the fault type.

[0166] The advantages of the control method in this embodiment are as follows:

[0167] 1. Customized control: Different speed calculation formulas can be fitted based on the measured data of water pumps of different specifications. This solution is not limited to water purifier flow control, but is also applicable to other equipment that requires control of water pump flow.

[0168] 2. Precise Calculation: This solution provides specific calculation formulas that can accurately calculate the target speed of the motor based on the outlet pressure and flow requirements, ensuring that the motor operates in the best condition and meets the performance requirements under different working conditions.

[0169] 3. High-efficiency response: By using the MCU main control circuit 302 to parse and process instructions, a fast response can be achieved, and the motor speed can be adjusted in a timely manner, so that the system can quickly adapt to changes in flow.

[0170] 4. Stable and reliable: Transmitting commands and parameters through the serial port optocoupler isolation circuit 304 can improve the system's anti-interference ability and ensure the stability and reliability of communication.

[0171] 5. Energy saving and consumption reduction: Adjusting the motor speed according to the actual flow demand and outlet pressure can prevent the motor from working at a non-optimal speed for a long time, thereby reducing energy consumption and improving the energy efficiency ratio.

[0172] 6. High versatility: This solution can be designed with different formulas according to different flow requirements, making it highly applicable to a variety of water purifiers or other occasions that require flow control.

[0173] 7. Safety: By precisely controlling the motor speed, equipment damage or safety hazards caused by improper speed can be avoided.

[0174] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A water pump motor for a water purifier, characterized in that: It includes a housing (1), a rear cover (2) and a drive plate (3), wherein the rear cover (2) is disposed at one end of the housing (1), and the drive plate (3) is connected to the rear cover (2) and located inside one end of the housing (1); The drive board (3) includes a PCB board (301), on which an MCU main control circuit (302) and a motor drive circuit (303), a serial port optocoupler isolation circuit (304) and a motor running status detection module are provided. The motor drive circuit (303) is used to control the rotation of the motor; The serial port optocoupler isolation circuit (304) is used for communication between the MCU main control circuit (302) and the water purifier motherboard; The motor operating status detection module is used to detect the operating status parameters of the motor.

2. The water pump motor for a water purifier according to claim 1, characterized in that: The motor operation status detection module includes a bus voltage detection circuit, a coil current detection circuit (306), an overcurrent detection circuit (307), a temperature and humidity detection circuit (308), and a vibration acceleration detection circuit (309); The bus voltage detection circuit is used to detect the bus voltage value; The coil current detection circuit (306) is used to detect the current value of the motor coil; The overcurrent detection circuit (307) is used to detect whether the current of the motor coil exceeds the specified value; The temperature and humidity detection circuit (308) is used to detect the operating temperature of the motor and the humidity inside the motor; The vibration acceleration detection circuit (309) is used to detect the vibration amplitude of the motor.

3. The water pump motor for a water purifier according to claim 1, characterized in that: The PCB board (301) is also provided with an auxiliary power supply circuit (310), which is used to supply power to the circuit modules on the PCB board (301).

4. The water pump motor for a water purifier according to claim 1, characterized in that: The housing (1) includes a first mounting part (11) and a second mounting part (12). A stator assembly (4) is provided in the first mounting part (11). The rear cover plate (2) is provided at the end of the second mounting part (12). The drive plate (3) is located in the second mounting part (12).

5. The water pump motor for a water purifier according to claim 4, characterized in that: The rear cover plate (2) has a sixth groove (21) on one edge that is connected to the second mounting part (12), and a third O-ring (211) is provided in the sixth groove (21).

6. The water pump motor for a water purifier according to claim 4, characterized in that: The first mounting part (11) is provided with a step (112) for axial positioning of the stator assembly (4).

7. The water pump motor for a water purifier according to claim 4, characterized in that: A wire hole (13) is provided between the first mounting part (11) and the second mounting part (12), and the coil wire end of the stator assembly (4) passes through the wire hole (13) and is connected to the drive plate (3) on the rear cover plate (2).

8. The water pump motor for a water purifier according to claim 4, characterized in that: A wire harness (311) is connected to the PCB board (301), and a wire clip (312) is provided on the wire harness (311). The end of the second mounting part (12) is provided with a notch (121) for mounting the wire clip (312).

9. The water pump motor for a water purifier according to claim 8, characterized in that: The notch (121) is provided with a first sealing surface (1211), a second sealing surface (1212) and a third sealing surface (1213), and the wire clamp (312) is provided with a first groove (3121) that fits with the first sealing surface (1211), a second groove (3122) that fits with the second sealing surface (1212) and a third groove (3123) that fits with the third sealing surface (1213).

10. The water pump motor for a water purifier according to claim 8, characterized in that: The wall surface of the notch (121) is provided with a plurality of first labyrinth grooves (1214) and first labyrinth teeth (1215), the first labyrinth teeth (1215) being located between two first labyrinth grooves (1214); the wall surface of the wire clamp (312) that mates with the notch (121) is provided with a plurality of second labyrinth grooves (3124) and second labyrinth teeth (3125), the second labyrinth teeth (3125) being located between two second labyrinth grooves (3124); the wall surface of the rear cover plate (2) that mates with the notch (121) is provided with a plurality of third labyrinth grooves (22) and third labyrinth teeth (23), the third labyrinth teeth (23) being located between two third labyrinth grooves (22).

11. The water pump motor for a water purifier according to claim 4, characterized in that: It also includes a front cover (5), which is disposed at the end of the first mounting part (11), and a first bearing chamber (51) is disposed at the center of the front cover (5); a fourth groove (52) is disposed at the connection between the front cover (5) and the first mounting part (11), and a first O-ring seal (53) is disposed in the fourth groove (52); a through hole (54) is disposed at the center of the front cover (5), and a fifth groove (55) is disposed on the outside of the through hole (54), and a second O-ring seal (56) is disposed in the fifth groove (55).

12. The water pump motor for a water purifier according to claim 11, characterized in that: The bottom of the first mounting part (11) is provided with a second bearing chamber (111).

13. The water pump motor for a water purifier according to claim 12, characterized in that: It also includes a rotor assembly (6), which includes a rotor shaft (61) and a rotor core (62). The outer wall of the rotor shaft (61) is provided with a rib (611). The rib (611) on the outer circle of the rotor shaft (61) is interference-fitted with the center hole of the rotor core (62). The rotor core (62) is located inside the stator assembly (4). One end of the rotor shaft (61) extends out from the through hole (54) of the front end cover (5) and is rotatably connected to the first bearing chamber (51) of the front end cover (5). The outer wall of one end of the rotor shaft (61) is interference-fitted with the inner ring of the second O-ring seal (56). The other end of the rotor shaft (61) is rotatably connected to the second bearing chamber (111) of the first mounting part (11).

14. The water pump motor for a water purifier according to claim 13, characterized in that: The rotor core (62) has several elongated holes (621) around its central hole.

15. A control method for a water pump motor in a water purifier as described in any one of claims 1 to 14, characterized in that, It includes the following steps: Step S1: The water purifier motherboard converts the user's instructions into motor start instructions and motor target speed parameters. The water purifier motherboard communicates with the MCU main control circuit (302) of the driver board (3) through the serial port optocoupler isolation circuit (304). Step S2: The MCU main control circuit (302) parses and processes the instructions and parameters from the water purifier motherboard module, and calculates the target speed value of the motor. Step S3: Based on the performance parameters of the water pump and the fitting of measured data, the MCU main control circuit (302) calculates the target speed value of the motor; Step S4: The MCU main control circuit (302) generates a motor speed control signal based on the target speed value of the motor and sends the motor speed control signal to the motor drive circuit (303). Step S5: The motor drive circuit (303) receives and processes the motor speed control signal to control the motor speed. Step S7: The MCU main control circuit (302) detects the motor's operating status parameters through the motor operating status detection module. If an abnormality occurs during motor operation, the MCU main control circuit (302) sends the corresponding fault code to the water purifier main board through the serial port optocoupler isolation circuit (304). The water purifier main board module takes appropriate action based on the fault type.

16. The control method according to claim 15, characterized in that: In step S2, the formula for calculating the target speed n of the motor is as follows: n = 551.05 + 97.57Q + 316.3P; Where Q is the flow rate of the water pump and P is the outlet pressure of the water pump.

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