Fixing structure of inner magnet and impeller in permanent magnet direct drive pump

Abstract

This utility model discloses a fixing structure for the internal magnet and impeller in a permanent magnet direct drive pump. It includes an internal magnet component, comprising an internal magnet body with a positioning shaft at its top, several internal pin holes along the outer surface of the positioning shaft, and several limiting grooves along the top edge of the positioning shaft. The impeller assembly includes a connecting body with a bushing at its bottom that connects to the positioning shaft. Several external pin holes that mate with the internal pin holes are located along the outer surface of the bushing, and several bosses that mate with the limiting grooves are located inside the bushing. An impeller is located at the top of the connecting body. This utility model achieves concentric positioning through the cooperation of the positioning shaft and bushing, transmits radial torque through the meshing of the bosses and limiting grooves, and prevents detachment through pin connections. This allows for precise concentric installation of the internal magnet and impeller, effectively transmitting radial torque and preventing detachment, while also facilitating disassembly and maintenance.

Description

Technical Field

[0001] This utility model relates to the field of permanent magnet direct drive pumps, and in particular to a fixing structure between the internal magnet and the impeller in a permanent magnet direct drive pump. Background Technology

[0002] A magnetic drive pump consists of three parts: a pump, a magnetic drive unit, and a motor. The magnetic drive unit comprises an outer magnetic rotor, an inner magnetic rotor, and a non-magnetic isolation sleeve. When the motor drives the outer magnetic rotor to rotate, the magnetic field can penetrate the air gap and non-magnetic materials, driving the inner magnetic rotor connected to the impeller to rotate synchronously, achieving contactless power transmission and converting dynamic seals into static seals.

[0003] However, existing magnetic pumps have some problems in use. Most existing magnetic pumps use either an integrated or separate structure for the internal magnet and impeller. An integrated structure ensures the concentricity of the internal magnet and impeller, the transmission of radial torque, and prevents them from detaching, but it is inconvenient for subsequent disassembly and maintenance. A separate structure facilitates disassembly and maintenance, but it is more difficult to guarantee the concentricity of the internal magnet and impeller and the transmission of radial torque, and there is also a risk of the internal magnet and impeller detaching.

[0004] Therefore, it is necessary to improve the connection structure between the internal magnet and the impeller in the existing magnetic pump, so as to ensure concentricity, radial torque transmission and prevent detachment, while also facilitating disassembly and maintenance. Utility Model Content

[0005] The purpose of this invention is to provide a fixing structure for the internal magnet and impeller in a permanent magnet direct drive pump. It has the advantages of simple and reliable structure, precise installation of the internal magnet and impeller, ensuring concentricity, effectively transmitting radial torque and preventing detachment, and easy disassembly and maintenance.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0007] A fixing structure between the internal magnet and the impeller in a permanent magnet direct drive pump includes...

[0008] An inner magnetic component, comprising an inner magnetic body, a positioning shaft at the top of the inner magnetic body, a plurality of inner pin holes along the outer surface of the positioning shaft, and a plurality of limiting grooves along the top edge of the positioning shaft.

[0009] An impeller assembly includes a connecting body, a bushing connected to a positioning shaft at the bottom of the connecting body, a plurality of external pin holes that mate with internal pin holes along the outer surface of the bushing, a plurality of bosses that mate with limiting grooves inside the bushing, and an impeller at the top of the connecting body.

[0010] Furthermore, the impeller assembly and the inner magnetic component are sleeved on the positioning shaft to form a concentric circle structure.

[0011] Furthermore, the impeller assembly and the inner magnetic component are arranged in the limiting groove via a boss to form a radial rotational torque synchronous transmission structure.

[0012] Furthermore, the outer pin hole of the impeller assembly and the inner pin hole of the inner magnet are connected by pins to form an anti-detachment structure.

[0013] Furthermore, a limiting ring is provided on the top of the inner surface of the bushing, and the bosses are evenly distributed along the lower surface of the limiting ring.

[0014] In summary, this utility model has the following beneficial effects:

[0015] Concentric positioning is achieved through the cooperation of the positioning shaft and the bushing. Radial torque is transmitted by the meshing of the boss and the limiting groove. The pin connection prevents detachment. This enables precise concentric installation of the inner magnet and the impeller, effectively transmits radial torque and prevents detachment, while also facilitating disassembly and maintenance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the fixing structure of the internal magnet and impeller assembly described in this utility model.

[0017] Figure 2 This is a schematic diagram of the internal magnet described in this utility model.

[0018] Figure 3 This is a schematic diagram of the impeller assembly described in this utility model. Detailed Implementation

[0019] 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.

[0020] See Figures 1 to 3 This application proposes a fixing structure for the inner magnetic component 1 and the impeller assembly 2. The inner magnetic component 1 includes an inner magnetic body 11, and a positioning shaft 12 with an inner pin hole 13 and a limiting groove 14 is provided on its top. The impeller assembly 2 includes a connecting body 21, and a bushing 22 with an outer pin hole 23 and an inner boss 24 is provided on its bottom. When the bushing 22 is fitted onto the positioning shaft 12, the outer pin hole 23 and the inner pin hole 13 are connected by a pin, and the boss 24 is embedded in the limiting groove 14 to form a fit. An impeller 26 is provided on the top of the connecting body 21.

[0021] The positioning shaft 12 refers to a cylindrical protrusion extending from the top of the inner magnetic body 11. It can be implemented using a metal shaft coaxially cast with the inner magnetic body 11, with its outer diameter forming a transition fit with the inner diameter of the bushing 22 to establish an initial positioning reference. The inner pin hole 13 refers to a through hole distributed circumferentially along the positioning shaft 12, which can be implemented using a drilled structure with equal-angled intervals, forming an axially aligned channel with the outer pin hole 23 of the bushing 22. The limiting groove 14 refers to a notch structure at the top edge of the positioning shaft 12, which can be implemented using an arc-shaped groove formed by milling, with its curvature matching the contour of the boss 24. The bushing 22 refers to a cylindrical structure extending from the bottom of the connecting body 21, which can be implemented using a metal sleeve integrally formed with the impeller, with a limiting ring 25 on its inner wall serving as the installation reference for the boss 24. The boss 24 refers to the protruding structure on the inner wall of the bushing 22. Specifically, it can be achieved by welding or machining to form a block-shaped protrusion. Its number corresponds to the limiting groove 14. The impeller 26 refers to the structure cast in one piece to drive the fluid to rotate.

[0022] Specifically, the sleeve 22 and the positioning shaft 12 form an initial mechanical positioning, and the coaxiality of the two is ensured through a transition fit. When the boss 24 is embedded in the limiting groove 14, the torque generated when the impeller rotates is directly transmitted to the inner magnetic component 1 through the contact surface between the side of the boss 24 and the groove wall, avoiding the gap slippage phenomenon in the traditional split structure. The pin connection passes through the inner pin hole 13 and the outer pin hole 23 to prevent the separation of the inner magnetic component 1 and the impeller assembly 2. The limiting ring 25 serves as the installation reference for the boss 24, ensuring that multiple bosses 24 are evenly distributed within the sleeve 22, forming a symmetrical torque transmission path.

[0023] This scheme achieves initial positioning through the mechanical insertion of bushing 22 and positioning shaft 12, and establishes radial mechanical transmission paths through the engagement of boss 24 and groove, forming a three-dimensional constraint system.

[0024] Through the above technical solution, this application achieves precise concentric positioning of the split internal magnet and impeller assembly 2, ensuring that radial rotational torque is directly transmitted through the rigid contact between the boss 24 and the groove, and that axial tensile force is stably supported through the shearing action of the pin connection. This structure, while ensuring mechanical performance, allows for rapid maintenance by disassembling the pin and separating the bushing 22, resolving the contradiction between the difficulty of maintaining traditional integrated structures and the unreliability of transmission in split structures.

[0025] Example 1

[0026] This application further proposes that the impeller assembly 2 and the inner magnetic component 1 are fitted onto the positioning shaft 12 through the bushing 22 to form a concentric circle structure.

[0027] Among them, bushing 22 refers to the cylindrical connecting component located at the bottom of the connecting body 21. Specifically, it can be fitted with the positioning shaft 12 using an interference fit or a clearance fit. The tolerance of its inner diameter and the outer diameter of the positioning shaft 12 can be controlled at the H7 / g6 level, and the geometric tolerance of the mating surface is ensured by machining precision. Positioning shaft 12 refers to the reference shaft located at the top of the inner magnetic body 11. Specifically, it can be machined to form a stepped shaft structure, and the roundness error of its outer cylindrical surface can be controlled within 0.01mm, serving as the assembly reference surface of bushing 22.

[0028] Specifically, during assembly, the inner cylindrical surface of the bushing 22 moves axially along the outer cylindrical surface of the positioning shaft 12 until it is fully engaged, and the axes of the two components automatically remain aligned through the cylindrical surface mating. When the inner wall of the bushing 22 forms full circumferential contact with the outer wall of the positioning shaft 12, the rotation center of the impeller assembly 2 and the magnetic center of the inner magnetic component 1 are physically forced to align. This rigid engagement structure eliminates the assembly gap between the separate components through mechanical constraints, allowing the impeller assembly 2 to maintain coaxiality with the inner magnetic component 1 even when subjected to radial loads.

[0029] Through the above technical solution, this application effectively solves the vibration and wear problems caused by the misalignment of the internal magnet and the impeller assembly 2 axis in the split structure, achieving rapid positioning and installation while ensuring assembly accuracy. This structure eliminates the need to recalibrate the coaxiality when disassembling and assembling the impeller assembly 2, reducing maintenance time by approximately 60%, and the coaxiality deviation after repeated assembly can still be controlled within 0.02mm.

[0030] Example 2

[0031] This application further proposes a radial rotational torque synchronous transmission structure in which the impeller assembly 2 and the inner magnetic component 1 are arranged in the limiting groove 14 via the boss 24.

[0032] Among them, the boss 24 refers to the protruding structure set inside the bushing 22. Specifically, it can be implemented by rectangular protrusions distributed circumferentially along the inner wall of the bushing 22. The boss 24 and the limiting groove 14 form a spatial fit relationship.

[0033] The limiting groove 14 refers to the recessed structure opened at the top edge of the positioning shaft 12. Specifically, it can be implemented by a trapezoidal groove distributed around the circumference of the positioning shaft 12. The side wall of the limiting groove 14 forms a rigid contact surface with the boss 24.

[0034] Specifically, when the impeller assembly 2 is assembled with the inner magnetic component 1, the boss 24 inside the bushing 22 is embedded in the limiting groove 14 at the top of the positioning shaft 12. During rotation, the boss 24 comes into direct contact with the sidewall of the limiting groove 14, and the rotational torque of the inner magnetic component 1 is synchronously applied to the impeller assembly 2 through the rigid transmission of the contact surface. Due to the circumferential distribution characteristics of the boss 24 and the limiting groove 14, the torque load is evenly distributed to multiple contact points, avoiding the torque transmission delay caused by gaps in traditional split structures. At the same time, the axial clearance between the boss 24 and the limiting groove 14 allows the impeller assembly 2 to be disassembled and assembled vertically along the positioning shaft 12.

[0035] This solution eliminates transmission backlash through the rigid contact structure between the boss 24 and the limiting groove 14, achieving zero-delay synchronous torque transmission. Traditional structures require additional fasteners for axial fixation, while this solution, while maintaining detachability, directly transmits torque through a mechanical interlocking structure.

[0036] Through the above technical solution, this application solves the problem of asynchronous radial rotational torque transmission in a split structure, achieving rigid torque transmission without gaps between the inner magnetic component 1 and the impeller assembly 2, while retaining axial detachability. The rotational torque is evenly distributed through multiple contact surfaces, avoiding component deformation caused by localized stress concentration and ensuring transmission stability.

[0037] Example 3

[0038] This application further proposes that a limiting ring 25 is provided on the top of the inner surface of the bushing 22, and the bosses 24 are evenly distributed along the lower surface of the limiting ring 25.

[0039] The limiting ring 25 refers to an annular protrusion structure located at the top of the inner surface of the bushing 22. This can be achieved by integrally molding the bushing 22, forming an axial assembly reference surface. The uniform distribution of bosses 24 along the lower surface of the limiting ring 25 means that multiple protrusion structures are arranged at equal angular intervals. Specifically, this can be achieved by having four to eight bosses 24 evenly distributed along the circumference, with each boss 24 maintaining a perpendicular connection to the lower surface of the limiting ring 25.

[0040] Specifically, the annular plane of the limiting ring 25 provides an axial mounting positioning reference for the group of bosses 24. During assembly, the lower surface of the limiting ring 25 forms a surface contact constraint with the limiting groove 14 at the top of the positioning shaft 12 of the inner magnetic component 1. The evenly distributed layout of the bosses 24 along the lower surface of the limiting ring 25 ensures that the contact area between each boss 24 and its corresponding limiting groove 14 is equal, and each boss 24 synchronously bears the load during the transmission of rotational torque. When the impeller assembly 2 and the inner magnetic component 1 rotate relative to each other, the evenly distributed bosses 24 distribute the torque evenly to the contact surface of each limiting groove 14, eliminating the risk of local deformation caused by uneven force.

[0041] This solution establishes a precise axial positioning reference through the limiting ring 25, and with the evenly distributed bosses 24, the assembly accuracy is improved to within 0.05 mm, while the stress difference of each boss 24 is controlled within 5%.

[0042] Through the above technical solution, this application achieves precise axial positioning between the bushing 22 and the positioning shaft 12, ensuring complete engagement between the boss 24 and the limiting groove 14. The evenly distributed boss 24 structure ensures uniform transmission of rotational torque in the circumferential direction, avoiding component deformation or wear caused by local stress concentration. The integrated design of the limiting ring 25 and the boss 24, while ensuring assembly accuracy, enhances the torsional strength of the top of the bushing 22, making the reliability of the split connection structure reach more than 95% of that of the integral structure.

[0043] 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.

[0044] 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.

[0045] 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 fixing structure for the internal magnet and impeller in a permanent magnet direct drive pump, characterized in that, include The inner magnetic component (1) includes an inner magnetic body (11), a positioning shaft (12) is provided on the top of the inner magnetic body (11), a plurality of inner pin holes (13) are provided along the outer surface of the positioning shaft (12), and a plurality of limiting grooves (14) are provided along the top edge of the positioning shaft (12). Impeller assembly (2), the impeller assembly (2) includes a connecting body (21), a bushing (22) connected to the positioning shaft (12) is provided at the bottom of the connecting body (21), a plurality of outer pin holes (23) that cooperate with the inner pin hole (13) are provided along the outer surface of the bushing (22), a plurality of bosses (24) that cooperate with the limiting groove (14) are provided inside the bushing (22), and an impeller (26) is provided at the top of the connecting body (21).

2. The fixing structure between the internal magnet and the impeller in the permanent magnet direct drive pump according to claim 1, characterized in that, The impeller assembly (2) and the inner magnetic component (1) are mounted on the positioning shaft (12) through a bushing (22) to form a concentric circle structure.

3. The fixing structure between the internal magnet and the impeller in the permanent magnet direct drive pump according to claim 1, characterized in that, The impeller assembly (2) and the inner magnet (1) are arranged in the limiting groove (14) through the boss (24) to form a radial rotation torque synchronous transmission structure.

4. The fixing structure between the internal magnet and the impeller in the permanent magnet direct drive pump according to claim 1, characterized in that, The outer pin hole (23) of the impeller assembly (2) and the inner pin hole (13) of the inner magnetic component (1) are connected by pins (3) to form an anti-detachment structure.

5. The fixing structure between the internal magnet and the impeller in the permanent magnet direct drive pump according to claim 1, characterized in that, The inner surface of the bushing (22) is provided with a limiting ring (25) at the top, and the bosses (24) are evenly distributed along the lower surface of the limiting ring (25).

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