Permanent magnet direct drive pump with bearing wear detection function

Abstract

The utility model discloses a permanent magnet direct drive pump with bearing wear detection function, including magnetic drive pump subassembly and bearing wear detection subassembly, the magnetic drive pump subassembly includes bottom plate, is installed with the casing on the bottom plate, is equipped with stator subassembly in the casing, is equipped with the base on one side of stator subassembly, and rotor subassembly is connected with the base swing, and one end of casing is connected with pump shell and constitutes fluid cavity, and impeller spare is located in fluid cavity, and is connected with rotor subassembly synchronous rotation, and the other end of casing is closed through back cover, bearing wear detection subassembly includes electrical box and sets up in the electrical cavity of back cover outer end surface, and electrical box is connected with electrical cavity and constitutes the electrical cavity body for installing circuit board, is equipped with the wire hole in the electrical cavity body, and the wire hole is used for passing through data line, and one end of data line is connected and installs detection element in permanent magnet direct drive pump, and the other end of data line is used for connecting the circuit board in electrical cavity body.

Description

Technical Field

[0001] This utility model relates to the field of permanent magnet direct drive pumps, and in particular to a permanent magnet direct drive pump with bearing wear detection function. Background Technology

[0002] As an important fluid transport device in modern industry, the permanent magnet direct-drive pump typically consists of three main parts: the pump body, the magnetic drive, and the electric motor. The magnetic drive employs a unique design with an external magnetic rotor, an internal magnetic rotor, and a non-magnetic isolation sleeve. Through magnetic field coupling, it achieves contactless power transmission, transforming the traditional dynamic seal into a static seal structure, effectively solving the leakage problem inherent in traditional mechanical seals. However, this structural design also brings new technical challenges during actual operation.

[0003] Because permanent magnet direct drive pumps use magnetic coupling transmission, their internal bearing components are subjected to alternating loads over a long period. As the equipment continues to operate, the bearings inevitably wear. This wear leads to a gradual increase in bearing clearance, which in turn causes a series of problems such as increased equipment vibration and operating noise, seriously affecting the pump's operational stability and service life.

[0004] Even more challenging is the fact that, due to the enclosed design of permanent magnet direct-drive pumps, maintenance personnel cannot directly observe the wear condition of the internal bearings. To monitor the internal wear, frequent disassembly and repair of the pump body are necessary. This maintenance method not only consumes significant manpower and time, but the repeated disassembly and reassembly process itself can also cause secondary damage to the equipment, further shortening its lifespan. Furthermore, traditional periodic maintenance methods are significantly delayed, making it difficult to detect early bearing wear in a timely manner. Repairs are often only carried out when obvious abnormalities have already occurred, at which point the bearings may already be severely damaged, increasing maintenance costs and downtime losses.

[0005] Therefore, it is necessary to improve such a structure to overcome the above-mentioned defects. Utility Model Content

[0006] The purpose of this invention is to provide a permanent magnet direct drive pump with bearing wear detection function, which has the advantages of real-time monitoring of bearing wear status and avoiding frequent disassembly and maintenance.

[0007] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0008] A permanent magnet direct drive pump with bearing wear detection function includes a magnetic pump assembly and a bearing wear detection assembly;

[0009] The magnetic pump assembly includes a base plate, a housing mounted on the base plate, a stator assembly inside the housing, a base on one side of the stator assembly, a rotor assembly movably connected to the base and capable of rotating under the drive of the outer stator assembly, one end of the housing being connected to the pump casing to form a fluid cavity, an impeller being located inside the fluid cavity and connected to the rotor assembly for synchronous rotation, and the other end of the housing being closed by a rear cover.

[0010] The bearing wear detection assembly includes an electrical box and an electrical cavity disposed on the outer end face of the rear cover. The electrical box and the electrical cavity are connected to form an electrical cavity for mounting a circuit board. A wire hole is provided in the electrical cavity for passing a data cable. One end of the data cable is connected to a detection element installed in the permanent magnet direct drive pump, and the other end of the data cable is used to connect to the circuit board in the electrical cavity.

[0011] Furthermore, the housing has a receiving cavity extending horizontally, the stator assembly is fixedly installed in the receiving cavity, the stator assembly has a mounting cavity extending horizontally, and the base is fixedly installed in the mounting cavity.

[0012] Furthermore, the base is provided with a connecting shaft, one end of the rotor assembly is provided with a shaft hole for pre-installed bearings, the rotor assembly is movably mounted on the connecting shaft through the bearings, and the impeller is fixedly connected to the other end of the rotor assembly.

[0013] Furthermore, one side of the pump casing is provided with a semi-open cavity that forms a fluid cavity with the casing, and the other side of the pump casing is provided with an inlet flange with an inlet port communicating with the fluid cavity. The top of the pump casing is provided with an outlet flange with an outlet port communicating with the fluid cavity.

[0014] Furthermore, the inner side of the rear cover is provided with a positioning hole for connecting to the housing, and a number of threaded holes for connecting to the permanent magnet direct drive pump are provided along the inner edge of the rear cover. A number of lifting eye holes for hoisting are provided on the outer side of the rear cover.

[0015] In summary, this utility model has the following beneficial effects:

[0016] In existing technologies, permanent magnet direct-drive pumps generally use magnetic drives to achieve contactless power transmission, but their bearing wear monitoring has significant shortcomings. After long-term operation, vibration problems caused by increased bearing clearance are difficult to monitor in real time, requiring maintenance personnel to frequently disassemble the pump body for manual inspection. This maintenance method is not only time-consuming but also accelerates equipment wear due to repeated disassembly and assembly, creating a vicious cycle of "inspection-damage-re-inspection," which seriously affects the continuity of industrial production.

[0017] To address these issues, researchers discovered a conflict between signal acquisition and equipment sealing in traditional detection methods. After numerous experiments, they found that embedding the detection element inside the pump body and establishing an independent signal channel was a feasible approach. By analyzing the pump body's structural characteristics, they ultimately determined to construct a closed electrical cavity in the rear cover area, using wire holes to achieve internal and external signal transmission, thus maintaining sealing integrity while avoiding electromagnetic interference.

[0018] This application provides a permanent magnet direct drive pump with bearing wear detection function. Through the collaborative design of the magnetic pump assembly and the bearing wear detection assembly, the circuit board in the electrical cavity receives data from the detection element in real time, realizing online monitoring of bearing wear status. This solves the problem of frequent disassembly and maintenance required by traditional permanent magnet direct drive pumps, and has the advantages of extending equipment service life and improving operational stability. Attached Figure Description

[0019] Figure 1 This is one of the schematic diagrams of the permanent magnet direct drive pump described in this utility model.

[0020] Figure 2 This is the second schematic diagram of the permanent magnet direct drive pump described in this utility model.

[0021] Figure 3 This is a schematic diagram of the structure of the back cover described in this utility model. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with the illustrations and specific embodiments.

[0023] like Figures 1 to 3 As shown, this utility model proposes a permanent magnet direct-drive pump with bearing wear detection function, comprising a magnetic pump assembly and a bearing wear detection assembly. The magnetic pump assembly includes a base plate 1, a housing 2 mounted on the base plate 1, a stator assembly 3 housed within the housing 2, a base 4 positioned to the side of the stator assembly 3, and a rotor assembly 5 movably connected to the base 4 and driven by the stator assembly 3. One end of the housing 2 is connected to a pump casing 7 to form a fluid cavity, and an impeller 6 is placed within the fluid cavity and linked with the rotor assembly 5. The other end of the housing 2 is closed by a rear cover 8. The bearing wear detection assembly includes an electrical box 9 and an electrical cavity 81 on the outer end face of the rear cover 8. These two components combine to form a circuit board mounting space. A wire through hole 82 is provided within the electrical cavity 81 for data cables to pass through, connecting the internal detection element to the circuit board.

[0024] The base plate 1 refers to the foundation component that supports the pump body structure. It can be cast from cast iron or alloy materials to ensure the installation accuracy of each component. The housing 2 is the protective structure that encloses the transmission components. It has a stepped mounting surface inside and uses a heat-shrinking process to fix the stator assembly 3, forming an electromagnetic shielding environment. The stator assembly 3 is the electromagnetic device that generates a rotating magnetic field. It adopts a fractional-slot concentrated winding structure, and the winding ends are impregnated with epoxy resin for curing, improving heat dissipation efficiency. The bearing wear detection component is an integrated monitoring system with an internal moisture-proof coating. The circuit board can be a vibration analysis module with a CAN bus interface.

[0025] Specifically, when the motor drives the outer magnetic rotor, the inner magnetic rotor drives the impeller 6 to rotate and transport the medium. The connecting shaft 41 inside the base 4 supports the rotor assembly 5 through a double-row angular contact bearing, and the detection element is embedded in the bearing housing to collect vibration signals. The signal is transmitted to the vibration analysis module inside the electrical cavity 81 via a shielded data line. When a specific high-frequency component appears in the spectrum, the system determines that the bearing clearance exceeds the threshold. The lifting eye hole 85 provided on the rear cover 8 allows the detection assembly to be completely disassembled for maintenance, avoiding damage to the pump body sealing structure.

[0026] Compared to existing technologies, traditional solutions require disassembling the pump body to access the detection points. This solution, however, achieves real-time monitoring during operation through built-in detection elements and a closed signal channel. In existing technologies, the detection circuitry is exposed within the fluid cavity and susceptible to corrosion. This solution independently positions the electrical cavity 81 on the outside of the rear cover 8, effectively isolating it from moisture and electromagnetic interference.

[0027] Through the above technical solution, this application achieves online assessment of bearing wear, automatically triggering an early warning when the axial vibration reaches a preset threshold. Maintenance personnel can formulate maintenance plans based on the warning level, avoiding downtime losses caused by sudden failures. The modular design of the detection components and pump body eliminates the need to disassemble the entire machine for sensor replacement, extending the overall service life of the equipment.

[0028] Example 1

[0029] This application further proposes that the housing 2 has a receiving cavity 21 extending horizontally, the stator assembly 3 is fixedly installed in the receiving cavity 21, the stator assembly 3 is provided with a mounting cavity 31 in the horizontal direction, and the base 4 is fixedly installed in the mounting cavity 31.

[0030] The receiving cavity 21 refers to a horizontally continuous cavity structure formed inside the housing 2, which can be formed by casting or machining. Its inner wall forms an interference fit with the outer contour of the stator assembly 3. This structure provides full circumferential support for the stator assembly 3, eliminating installation misalignment caused by local gaps. The mounting cavity 31 is a cylindrical cavity extending axially inside the stator assembly 3, which can be formed by turning. Its axis coincides with the axis of the receiving cavity 21. This design ensures the coaxiality of the base 4 and the stator assembly 3, avoiding magnetic force transmission path deviation. The base 4 refers to a metal component with a connecting shaft 41, which can be formed by welding a flange to the shaft. Its outer diameter forms a transition fit with the mounting cavity 31. This component, through rigid connection with the mounting cavity 31, forms a complete force transmission chain from the rotor to the housing 2.

[0031] Specifically, the horizontally continuous structure of the receiving cavity 21 provides a bidirectional positioning reference for the stator assembly 3 during installation, eliminating the cantilever effect caused by traditional single-sided installation. When the stator assembly 3 is pressed into the receiving cavity 21, the uniform contact between its outer surface and the inner wall of the cavity forms a radial constraint, preventing circumferential movement during operation. The axial extension feature of the mounting cavity 31 allows the base 4 to be positioned in a single direction during assembly, ensuring that the connecting shaft 41 coincides with the rotation axis of the rotor assembly 5. The base 4 is fixed to the end of the mounting cavity 31 by an interference fit, forming a rigid support system from the rotor assembly 5 to the housing 2, directly transmitting the vibration energy generated by bearing wear to the overall structure of the housing 2. This three-level nested installation structure forms an axially symmetrical force transmission path, effectively suppressing resonance caused by local loosening.

[0032] This design achieves full circumferential contact between the receiving cavity 21 and the stator assembly 3, ensuring a uniform distribution of electromagnetic force across the housing 2 and preventing localized stress concentration. In existing technologies, the base 4 is typically mounted independently on the pump body end face. Compared to this design, which integrates the base 4 within the stator assembly 3, this lacks a direct path for axial force transmission, making it prone to vibration amplification after bearing wear.

[0033] Through the above technical solution, this application achieves a gapless rigid connection between the stator assembly 3 and the housing 2, directly converting the rotational vibration of the rotor into damped vibration of the overall structure of the housing 2. The coaxial assembly of the stator mounting cavity 31 and the base 4 eliminates the accumulated tolerances caused by traditional multi-part assembly, ensuring that the axial force of the magnetic drive system is always transmitted in the predetermined direction. The horizontally penetrating receiving cavity 21 forms a symmetrical support system, effectively dispersing the lateral vibration energy caused by bearing wear.

[0034] Example 2

[0035] This application further proposes that the base 4 is provided with a connecting shaft 41, one end of the rotor assembly 5 is provided with a shaft hole 51 for pre-installed bearings, the rotor assembly 5 is movably mounted on the connecting shaft 41 through the bearings, and the impeller 6 is fixedly connected to the other end of the rotor assembly 5.

[0036] The connecting shaft 41 refers to the cylindrical support structure fixed on the base 4, which can be implemented using a stepped shaft or a smooth shaft structure. Its function is to provide an axial positioning reference for the rotor assembly 5 and ensure the uniformity of the gap between the rotor and the stator. The pre-installed bearing shaft hole 51 refers to the assembly hole machined at the end of the rotor assembly 5. The bearing can be pre-pressed into the shaft hole 51 using an interference fit or heat fitting process to form a modular assembly. Its function is to reduce adjustment procedures during on-site installation through standardized assembly. Movable installation refers to the rotor assembly 5 forming a rotatable fit with the connecting shaft 41 through bearings. This can be achieved using deep groove ball bearings or angular contact bearings. Its function is to limit radial runout and axial movement while ensuring rotational flexibility. Fixed connection refers to the non-movable assembly method between the impeller component 6 and the rotor assembly 5. This can be achieved through a keyway fit or flange bolt connection. Its function is to ensure the synchronization of power transmission and avoid additional vibration loads caused by connection gaps.

[0037] Specifically, after the connecting shaft 41 is installed on the base 4, the rotor assembly 5 is directly sleeved onto the connecting shaft 41 through the pre-installed bearing shaft hole 51, forming an axial positioning constraint. This modular structure allows the rotor assembly 5 to be positioned simply by pushing it axially along the connecting shaft 41 without repeated gap adjustments during installation. The mating surfaces of the bearing and the connecting shaft 41 are precision machined to ensure a constant gap between the rotor assembly 5 and the stator during rotation. The impeller 6 and the other end of the rotor assembly 5 are rigidly connected to achieve synchronous rotation, with no relative displacement in the power transmission path, thus avoiding the superposition of vibration energy caused by loose connections.

[0038] This solution utilizes the connection between the connecting shaft 41 and the pre-installed bearing shaft hole 51 to move the bearing clearance control process forward to the modular production stage. During on-site assembly, only axial positioning needs to be completed, avoiding the accumulation of errors caused by manual adjustments. In addition, the fixed connection between the impeller component 6 and the rotor assembly 5 eliminates the fretting wear that may occur with traditional keyed or threaded connections, further reducing the vibration source.

[0039] Through the above technical solution, this application effectively reduces the vibration amplitude caused by bearing wear and reduces pump body structural damage caused by intensified vibration. Meanwhile, the modular assembly structure allows for the replacement of rotor assembly 5 without disassembling the stator or adjusting the clearance, significantly shortening maintenance time and extending the actual service life of the bearings.

[0040] Example 3

[0041] This application further proposes that a semi-open cavity body is provided on one side of the pump casing 7, which forms a fluid cavity with the casing 2, and an inlet flange 71 is provided on the other side of the pump casing 7. An inlet port 72 communicating with the fluid cavity is provided on the inlet flange 71, and an outlet flange 73 is provided on the top of the pump casing 7. An outlet port 74 communicating with the fluid cavity is provided on the outlet flange 73.

[0042] Among them, the semi-open cavity body refers to the pump casing 7 having an opening structure that is not completely closed on one side. Specifically, it can be formed by casting or welding processes to form a semi-enclosed cavity. Through this opening, it can be connected with the casing 2 to form a completely sealed fluid cavity, reducing the number of assembly parts and reducing the risk of leakage.

[0043] The inlet flange 71 refers to the connecting disc structure located on the side of the pump casing 7. Specifically, it can be a ring flange fixed with bolts, allowing the inlet 72 to extend horizontally into the fluid cavity, guiding the fluid into the cavity in an axial flow manner and reducing vibration caused by fluid impact. The inlet 72 refers to the fluid passage that passes through the inlet flange 71. Specifically, it can be a circular or elliptical cross-section pipe, with its axis arranged parallel to the rotation axis of the impeller 6, so that the fluid enters the fluid cavity uniformly.

[0044] The outlet flange 73 refers to the connecting disc structure located on the top of the pump casing 7. Specifically, it can be a vertically extending tubular flange, causing the outlet 74 to extend vertically, utilizing the combined effect of gravity and fluid pressure to improve discharge efficiency. The outlet 74 refers to the fluid passage that passes through the outlet flange 73. Specifically, it can be a gradually expanding pipe structure to avoid eddy current losses at the outlet.

[0045] Specifically, the semi-open cavity of the pump casing 7 forms a closed fluid cavity after docking with the casing 2. When the impeller 6 rotates within the cavity, fluid enters the cavity horizontally through the inlet 72 of the inlet flange 71, and after being pressurized by the impeller 6, it is vertically discharged from the outlet 74 of the top outlet flange 73. The spatial separation of the inlet flange 71 and the outlet flange 73 creates an orthogonal relationship between the fluid input and output paths, improving the uniformity of fluid distribution around the impeller 6 and effectively suppressing radial load fluctuations on the bearings. The integrated structure of the semi-open cavity reduces assembly errors caused by traditional multi-part splicing, reduces the number of sealing surfaces at the flange connection, and lowers the risk of fluid leakage.

[0046] This solution uses a combination of a semi-open oral cavity and shell 2 to directly form a single sealing surface, and a combination of a horizontally arranged inlet flange 71 and a vertically arranged outlet flange 73 to make the fluid path spatially orthogonal. This avoids the leakage risk of multiple sealing surfaces in traditional structures and eliminates the vortex phenomenon generated by coaxial flow channels.

[0047] Through the above technical solutions, this application simplifies the assembly of the fluid cavity structure, improves sealing reliability, and optimizes the spatial layout of the fluid transmission path, thereby reducing bearing load fluctuations and enhancing equipment operational stability. The axial and radial separation design of the fluid input and output channels reduces the number of parts that need to be disassembled during maintenance, improving maintenance efficiency.

[0048] Example 4

[0049] This application further proposes that the inner side of the rear cover 8 is provided with a positioning hole 83 for connecting with the housing 2, and a plurality of threaded holes 84 for connecting with the permanent magnet direct drive pump are provided along the inner side edge of the rear cover 8, and a plurality of lifting eye holes 85 for hoisting are provided on the outer side of the rear cover 8.

[0050] The positioning hole 83 is a hole structure used for axial positioning during assembly with the housing 2. Specifically, it can be a precision-machined circular hole with a matching inner diameter. The positioning hole 83 mates with the positioning shaft at the end of the housing 2 to eliminate radial offset during assembly. The threaded hole 84 refers to bolt connection holes distributed along the edge of the rear cover 8. Specifically, it can be implemented using equally spaced threaded through holes. Multiple sets of bolts secure the rear cover 8 to the pump body, forming a uniformly distributed connection force. The lifting eye hole 85 is an annular through hole located on the outer surface of the rear cover 8. Specifically, it can be implemented using a welded or cast integral metal lifting eye structure. The lifting eye engages with the hook of external lifting tools, providing a support point for equipment assembly and disassembly.

[0051] Specifically, after the positioning hole 83 cooperates with the positioning shaft of the housing 2, it can limit the horizontal displacement of the rear cover 8 and ensure that the sealing surface between the rear cover 8 and the housing 2 is completely in contact; the threaded hole 84 applies uniform preload through multiple sets of bolts to avoid sealing failure caused by local stress concentration; the lifting eye hole 85 can directly suspend the lifting equipment during equipment maintenance, so that the rear cover 8 is subjected to uniform force and prevents the housing 2 from deforming due to uneven force during disassembly and assembly.

[0052] This solution achieves assembly reference positioning through positioning hole 83, improves connection reliability by combining multiple sets of threaded holes 84, and integrates a dedicated lifting eye hole 85 on the outside to form a complete positioning-fixing-lifting functional module.

[0053] Through the above technical solutions, this application achieves precise alignment and installation between the rear cover 8 and the housing 2, eliminating the potential for sealing leakage caused by assembly deviations; the multi-point bolt fixing enhances the vibration resistance of the connection structure; the lifting eye hole 85 provides a standardized lifting interface for maintenance operations, avoiding equipment damage caused by tool misoperation during disassembly and assembly, while shortening maintenance operation time.

[0054] In this document, the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer", "vertical", and "horizontal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the purpose of clarifying the technical solution and for the convenience of description, and therefore should not be construed as limiting the present utility model.

[0055] In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A permanent magnet direct-drive pump with bearing wear detection function, characterized in that, Includes magnetic pump components and bearing wear detection components; The magnetic pump assembly includes a base plate (1), a housing (2) is mounted on the base plate (1), a stator assembly (3) is provided inside the housing (2), a base (4) is provided on one side of the stator assembly (3), a rotor assembly (5) is movably connected to the base (4) and can rotate under the drive of the stator assembly (3) on the outside, one end of the housing (2) is connected to the pump housing (7) to form a fluid cavity, an impeller (6) is located in the fluid cavity and is connected to the rotor assembly (5) to rotate synchronously, and the other end of the housing (2) is closed by a rear cover (8); The bearing wear detection assembly includes an electrical box (9) and an electrical cavity (81) disposed on the outer end face of the rear cover (8). The electrical box (9) and the electrical cavity (81) are connected to form an electrical cavity for mounting a circuit board. A wire hole (82) is provided in the electrical cavity for passing through a data cable. One end of the data cable is connected to a detection element installed in the permanent magnet direct drive pump, and the other end of the data cable is used to connect to the circuit board in the electrical cavity.

2. The permanent magnet direct drive pump with bearing wear detection function according to claim 1, characterized in that, The housing (2) has a receiving cavity (21) extending horizontally, the stator assembly (3) is fixedly installed in the receiving cavity, the stator assembly (3) has a mounting cavity (31) in the horizontal direction, and the base (4) is fixedly installed in the mounting cavity (31).

3. The permanent magnet direct drive pump with bearing wear detection function according to claim 2, characterized in that, The base (4) is provided with a connecting shaft (41), and one end of the rotor assembly (5) is provided with a shaft hole (51) for pre-installed bearings. The rotor assembly (5) is movably installed on the connecting shaft (41) through the bearings, and the impeller (6) is fixedly connected to the other end of the rotor assembly (5).

4. The permanent magnet direct drive pump with bearing wear detection function according to claim 1, characterized in that, The pump casing (7) has a semi-open cavity on one side that forms a fluid cavity with the casing (2), and an inlet flange (71) on the other side of the pump casing (7). An inlet port (72) communicating with the fluid cavity is provided on the inlet flange (71), and an outlet flange (73) communicating with the fluid cavity is provided on the top of the pump casing (7).

5. The permanent magnet direct drive pump with bearing wear detection function according to claim 1, characterized in that, The inner side of the rear cover (8) is provided with a positioning hole (83) for connecting with the housing (2), and a number of threaded holes (84) for connecting with the permanent magnet direct drive pump are provided along the inner side edge of the rear cover (8). A number of lifting eye holes (85) for hoisting are provided on the outer side of the rear cover (8).

Images