Bearingless permanent magnet synchronous motor and screw pump

Abstract

The utility model relates to the technical field of motors, and discloses a bearingless permanent magnet synchronous motor and a screw pump, the bearingless permanent magnet synchronous motor comprises a casing, and a stator iron core, a rotor iron core and an inner hole rotating shaft which are sequentially arranged in the casing from outside to inside; a stator winding is arranged on the stator core, the rotor core is sleeved on the inner hole rotating shaft and provided with magnetic steel, a centrifugal wind wheel is arranged at the tail end of the inner hole rotating shaft, the outer diameter of the centrifugal wind wheel is smaller than or equal to that of the rotor assembly, and a central through hole with the hole diameter larger than that of the rotor assembly is formed in the machine shell. By optimizing the design of the centrifugal wind wheel, on one hand, the outer diameter of the centrifugal wind wheel does not exceed the maximum size of the rotor assembly, the installation steps are simplified, the whole motor system is more compact, the needed space is reduced, on the other hand, the heat dissipation performance is improved, and it is ensured that the motor can still keep good working temperature under high load. The screw pump is more convenient to assemble, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, and particularly relates to a bearingless permanent magnet synchronous motor and a screw pump. Background Art

[0002] Since the bearingless permanent magnet synchronous motor has no physically contacted bearings, the wear caused by friction is reduced. This not only improves the overall working efficiency of the motor but also extends the service life of the motor. When the bearingless permanent magnet synchronous motor is used as the driving source of the screw pump, it can provide a higher level of performance for the screw pump, which helps to maintain the stable operation of the pump and reduce the fluctuations during the fluid transportation process.

[0003] In order to improve the heat dissipation performance of the bearingless permanent magnet synchronous motor, multiple straight fan blades are usually arranged on the rotor assembly to discharge the heat inside the motor to the outside. However, during the research and development design, it is found that the diameter of the straight fan blades needs to be increased to meet the heat dissipation requirements. After the diameter of the straight fan blades is increased, it will be much larger than the diameter of the rotor assembly, which will cause very troublesome installation of the bearingless permanent magnet synchronous motor. To avoid the interference of the straight fan blades during installation, the rotor assembly and the straight fan blades cannot be pre-assembled in advance. The specific installation steps are as follows: first, the rotor assembly is sleeved on the screw, then the stator assembly is installed on the pump body so that the stator assembly sleeves the rotor assembly, and finally the straight fan blades are installed on the rotor assembly.

[0004] It can be seen that the existing technology still needs to be improved. Summary of the Utility Model

[0005] In view of the deficiencies of the above-mentioned existing technology, the purpose of the utility model is to provide a bearingless permanent magnet synchronous motor and a screw pump, aiming to facilitate the installation of the bearingless permanent magnet synchronous motor on the premise that the bearingless permanent magnet synchronous motor meets the heat dissipation requirements.

[0006] To achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A bearingless permanent magnet synchronous motor includes a housing, a stator core, a rotor core, and an inner hole rotating shaft that are sequentially arranged inside the housing from outside to inside; a stator winding is provided on the stator core, the rotor core is sleeved on the inner hole rotating shaft and a permanent magnet is provided on the rotor core. The housing, the stator core, and the stator winding are combined to form a stator assembly, and the rotor core, the permanent magnet, and the inner hole rotating shaft are combined to form a rotor assembly. A centrifugal fan is provided at the tail end of the inner hole rotating shaft, and the outer diameter of the centrifugal fan is less than or equal to the outer diameter of the rotor assembly. A central through hole with a diameter larger than the rotor assembly is opened on the housing, and the centrifugal fan is located outside the housing; a first keyway extending along the axial direction is opened on the inner peripheral wall of the inner hole rotating shaft.

[0008] As a further improvement of the above technical solution, the centrifugal impeller includes a front annular wheel plate, a rear annular wheel plate, and a plurality of blades arranged in an array and connecting the front annular wheel plate and the rear annular wheel plate. A positioning ring body protrudes from the center of the front end face of the front annular wheel plate. A plurality of mounting holes are arranged around the outer periphery of the inner hole of the front annular wheel plate. Threaded holes with the same number and one-to-one correspondence as the mounting holes are formed on the rear end face of the inner hole rotating shaft. Mounting screws pass through the mounting holes and are connected to the threaded holes.

[0009] As a further improvement of the above technical solution, the housing includes a heat dissipation jacket, a first flange plate provided at the front end of the heat dissipation jacket, and a rear cover plate provided at the rear end of the heat dissipation jacket. The center through hole is formed on the first flange plate and the rear cover plate.

[0010] As a further improvement of the above technical solution, a floor block is fixedly provided at the bottom of the heat dissipation jacket, and a locking hole is formed on the floor block.

[0011] As a further improvement of the above technical solution, a wind hood located outside the centrifugal impeller is installed at the tail of the housing, and heat dissipation grid holes are formed on the wind hood.

[0012] A front rotor pressing plate and a rear rotor pressing plate are respectively arranged at the front end and the rear end of the rotor core; a positioning convex ring is arranged on the outer peripheral wall of the rear end portion of the inner hole rotating shaft, and an axially extending second key groove is formed on the outer peripheral wall of the inner hole rotating shaft. The rotor core is connected to the second key groove of the inner hole rotating shaft by a key connection manner. The rotor core is sleeved on the inner hole rotating shaft and the rear end of the rotor core abuts against the positioning convex ring. A clamping groove matched with the positioning convex ring is provided on the rear rotor pressing plate.

[0013] As a further improvement of the above technical solution, a plurality of tightening screws arranged in a circumferential array and axially penetrating through the rotor core, the front rotor pressing plate and the rear rotor pressing plate are provided on the rotor core. A front tightening nut is threadedly connected to the front end portion of the tightening screw, and a rear tightening nut is threadedly connected to the rear end portion of the tightening screw; the front tightening nut and the rear tightening nut are tightened to clamp the rotor core jointly by the front rotor pressing plate and the rear rotor pressing plate.

[0014] The present utility model also provides a screw pump, which includes the bearingless permanent magnet synchronous motor as described above, a pump body, and a screw rotatably connected to the pump body. The rear end of the screw is inserted into the inner hole rotating shaft and is connected to the first key groove of the inner hole rotating shaft by a key connection manner; a second flange plate is provided at the rear end portion of the pump body, and the first flange plate and the second flange plate are connected by docking screws.

[0015] Advantages of the present utility model: Compared with the prior art, the bearingless permanent magnet synchronous motor provided by the present utility model simplifies the installation steps and makes the entire motor system more compact by optimizing the design of the centrifugal impeller, reducing the required space while ensuring that its outer diameter does not exceed the maximum size of the rotor assembly. On the other hand, it improves the heat dissipation performance, ensuring that the motor can maintain a good operating temperature under high loads. The assembly of the screw pump driven by the bearingless permanent magnet synchronous motor is more convenient, improving production efficiency. Brief Description of the Drawings

[0016] Figure 1 It is a cross-sectional view of the bearingless permanent magnet synchronous motor.

[0017] Figure 2 It is a three-dimensional view of the bearingless permanent magnet synchronous motor Figure 1 .

[0018] Figure 3 It is a three-dimensional view of the bearingless permanent magnet synchronous motor Figure 2 .

[0019] Figure 4 It is a three-dimensional view of the centrifugal impeller.

[0020] Figure 5 It is a three-dimensional view of the inner hole rotating shaft Figure 1 .

[0021] Figure 6 It is a three-dimensional view of the inner hole rotating shaft Figure 2 .

[0022] Figure 7 It is a structural schematic diagram of the screw pump.

[0023] Description of the main component symbols: 11 - housing, 111 - heat dissipation jacket, 112 - first flange, 113 - rear cover plate, 114 - central perforation, 12 - stator core, 21 - rotor core, 22 - inner hole rotating shaft, 221 - threaded hole, 222 - positioning convex ring, 223 - second keyway, 224 - first keyway, 23 - front rotor pressure plate, 24 - rear rotor pressure plate, 3 - centrifugal impeller, 31 - front annular plate, 32 - rear annular plate, 33 - blades, 34 - positioning ring body, 35 - mounting hole, 36 - mounting screw, 4 - wind hood, 41 - heat dissipation grid holes, 5 - anchor block, 51 - locking hole, 61 - pump body, 62 - screw, 63 - second flange, 64 - docking screw. Detailed Description of the Preferred Embodiment

[0024] The present utility model provides a bearingless permanent magnet synchronous motor and a screw pump. To make the objectives, technical solutions and effects of the present utility model clearer and more definite, the following further elaborates on the present utility model with reference to the accompanying drawings and by way of examples. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the protection scope of the present utility model.

[0025] Please refer to Figure 1 , the present utility model provides a bearingless permanent magnet synchronous motor, including a motor housing 11, a stator core 12, a rotor core 21 and an inner hole rotating shaft 22 which are sequentially arranged inside the motor housing 11 from outside to inside; a stator winding is provided on the stator core 12, the rotor core 21 is sleeved on the inner hole rotating shaft 22 and permanent magnets are provided on the rotor core 21. The motor housing 11, the stator core 12 and the stator winding are combined to form a stator assembly, and the rotor core 21, the permanent magnets and the inner hole rotating shaft 22 are combined to form a rotor assembly. A centrifugal fan 3 is provided at the tail end of the inner hole rotating shaft 22, and the outer diameter of the centrifugal fan 3 is less than or equal to the outer diameter of the rotor assembly. A central through hole 114 with a hole diameter larger than the rotor assembly is provided on the motor housing 11, and the centrifugal fan 3 is located outside the motor housing 11; a first keyway 224 extending axially is provided on the inner peripheral wall of the inner hole rotating shaft 22.

[0026] Compared with the traditional straight fan blade structure, for the centrifugal fan 3, under the condition of obtaining the same heat dissipation effect, the diameter of the centrifugal fan 3 is smaller, and the outer diameter of the centrifugal fan 3 meets the requirement of not being greater than the outer diameter of the rotor assembly, which means that the inner hole rotating shaft 22 can be pre-connected with the centrifugal fan 3 without on-site installation. After the rotor assembly is installed on the screw 62 and then the stator assembly is installed, both the centrifugal fan 3 and the rotor assembly can smoothly pass through the central through hole 114, avoiding interference problems during the installation process, reducing on-site installation steps, making the installation of the bearingless permanent magnet synchronous motor more simple and fast, thereby reducing the installation difficulty and cost.

[0027] When the bearingless permanent magnet synchronous motor works, the rotor assembly rotates relative to the stator assembly. As the rotor assembly rotates, the centrifugal fan 3 also rotates together, and the heat generated inside the motor is pumped outwards by the centrifugal fan 3 for discharge, so as to achieve the purpose of heat dissipation.

[0028] Compared with the prior art, the bearingless permanent magnet synchronous motor provided by the present utility model optimizes the design of the centrifugal fan 3. On the one hand, its outer diameter does not exceed the maximum size of the rotor assembly, which not only simplifies the installation steps, but also makes the entire motor system more compact, reducing the required space. On the other hand, it improves the heat dissipation performance, ensuring that the motor can still maintain a good working temperature under high load.

[0029] Specifically, see Figure 4As shown, the centrifugal impeller 3 includes a front annular wheel plate 31, a rear annular wheel plate 32, and multiple blades 33 arranged in an array and connecting the front annular wheel plate 31 and the rear annular wheel plate 32. A positioning ring body 34 protrudes from the center of the front end face of the front annular wheel plate 31. A plurality of mounting holes 35 are arranged around the outer periphery of the inner hole of the front annular wheel plate 31. Threaded holes 221 with the same number and one-to-one correspondence as the mounting holes 35 are provided on the rear end face of the inner hole rotating shaft 22. The mounting screws 36 pass through the mounting holes 35 and are connected to the threaded holes 221. The design of the positioning ring body 34 ensures the precise alignment between the centrifugal impeller 3 and the inner hole rotating shaft 22, thereby enhancing the connection stability between the two. After the mounting holes 35 and the threaded holes 221 are aligned and then connected by the mounting screws 36, the installation and disassembly of the centrifugal impeller 3 become very convenient, facilitating later maintenance and replacement. The design of the blades 33 between the front annular wheel plate 31 and the rear annular wheel plate 32 can effectively guide the airflow and improve the heat dissipation efficiency. The array arrangement of the blades 33 makes the airflow distribution more uniform, thereby enhancing the overall heat dissipation performance.

[0030] It can be understood that the diameter of the centrifugal impeller 3 is not greater than the outer diameter of the rotor assembly, that is, the diameters of the front annular wheel plate 31 and the rear annular wheel plate 32 of the centrifugal impeller 3 are not greater than the outer diameter of the rotor assembly.

[0031] Further, as shown in Figure 1 and Figure 2 As shown, the machine shell 11 includes a heat dissipation jacket 111, a first flange 112 provided at the front end of the heat dissipation jacket 111, and a rear cover plate 113 provided at the rear end of the heat dissipation jacket 111. The central perforation 114 is provided on the first flange 112 and the rear cover plate 113. The design of the heat dissipation jacket 111 increases the surface area of the machine shell 11, which is beneficial to the rapid dissipation of heat, thereby improving the heat dissipation performance of the motor and ensuring that the motor can still maintain a relatively low working temperature under high load conditions. The central perforation 114 on the first flange 112 and the rear cover plate 113 provides a necessary passage for the installation of the stator assembly. The rotor assembly and the centrifugal impeller 3 can smoothly pass through the central perforation 114, making the installation process more convenient.

[0032] Preferably, as shown in Figure 2 As shown, a floor block 5 is fixedly provided at the bottom of the heat dissipation jacket 111, and a locking hole 51 is provided on the floor block 5. The setting of the floor block 5 increases the contact area between the motor and the installation surface, which helps to improve the installation stability of the motor. Especially in an environment with large vibrations, it can reduce the vibration and displacement of the motor.

[0033] Preferably, as shown in Figure 1 and Figure 3As shown, a wind hood 4 is installed at the tail of the housing 11 and is located outside the centrifugal impeller 3. Heat dissipation grid holes 41 are formed in the wind hood 4. The design of the wind hood 4 guides the airflow generated by the centrifugal impeller 3 in a specific direction, ensuring the effective utilization of the airflow, thereby improving the heat dissipation efficiency. The existence of the heat dissipation grid holes 41 enables air to flow in and out smoothly, helping to carry away more heat. The presence of the wind hood 4 can prevent foreign objects from entering the motor interior, protecting the motor from external factors, and at the same time avoiding accidental contact of personnel with the high-speed rotating centrifugal impeller 3, improving the use safety.

[0034] Specifically, as shown in Figure 1 , Figure 5 and Figure 6 As shown, a front rotor pressing plate 23 and a rear rotor pressing plate 24 are respectively arranged at the front end and the rear end of the rotor core 21; a positioning convex ring 222 is arranged on the outer peripheral wall of the rear end portion of the inner hole rotating shaft 22, and an axially extending second key groove 223 is formed in the outer peripheral wall of the inner hole rotating shaft 22. The rotor core 21 is connected to the second key groove 223 of the inner hole rotating shaft 22 by a key connection. The rotor core 21 is sleeved on the inner hole rotating shaft 22 and the rear end of the rotor core 21 abuts against the positioning convex ring 222. A clamping groove cooperating with the positioning convex ring 222 is provided on the rear rotor pressing plate 24. When installing the rotor core 21, the rotor core 21 is pressed onto the inner hole rotating shaft 22 by a hydraulic press until the rear end of the rotor core 21 abuts against the positioning convex ring 222. The positioning convex ring 222 limits the rearward movement of the rotor core 21. Then, by providing a clamping groove on the rear rotor pressing plate 24 that cooperates with the positioning convex ring 222, the positioning convex ring 222 restricts the forward movement of the rear rotor pressing plate 24. When the rear rotor pressing plate 24 and the rotor core 21 are fixedly connected, the rotor core 21 and the rear rotor pressing plate 24 are axially positioned and cannot move axially any more, thus solving the problem of the axial movement of the rotor core 21 and ensuring the stability of the rotation of the rotor assembly.

[0035] In order to facilitate the assembly and combination of the front rotor pressing plate 23 and the rear rotor pressing plate 24 with the rotor core 21, in this embodiment, a plurality of tightening screws are provided on the rotor core 21 and are arranged in a circumferential array and axially penetrate through the rotor core 21, the front rotor pressing plate 23 and the rear rotor pressing plate 24. A front tightening nut is threadedly connected to the front end portion of the tightening screw, and a rear tightening nut is threadedly connected to the rear end portion of the tightening screw; as long as the front tightening nut and the rear tightening nut are tightened, the front rotor pressing plate 23 and the rear rotor pressing plate 24 can jointly clamp the rotor core 21, and the rotor core 21 is also fixed in position under the restriction of the positioning convex ring 222, solving the problem of the axial movement of the rotor core 21.

[0036] As shown in Figure 7As shown in the figure, the present utility model further provides a screw pump, which includes a bearingless permanent magnet synchronous motor as described in any of the above embodiments, a pump body 61, and a screw 62 rotatably connected to the pump body 61. The rear end of the screw 62 is inserted into the inner hole rotating shaft 22 and connected to the first keyway 224 of the inner hole rotating shaft 22 in a key connection manner, ensuring a firm connection between the two and improving the stability and reliability of transmission. A second flange 63 is provided on the rear end portion of the pump body 61, and the first flange 112 and the second flange 63 are connected by butt screws 64, simplifying the installation process of the screw pump and making the installation more rapid and convenient. During operation, the magnetic field interaction between the stator assembly and the rotor assembly of the bearingless permanent magnet synchronous motor generates a rotational force on the inner hole rotating shaft 22, thereby driving the screw 62 to rotate. Therefore, as the driving source of the screw pump, the bearingless permanent magnet synchronous motor reduces mechanical losses and improves the overall driving efficiency, making the screw pump more efficient when transporting fluids.

[0037] The design optimization of the bearingless permanent magnet synchronous motor makes the assembly of the screw pump more convenient and improves production efficiency.

[0038] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0039] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that allows mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, and can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0040] It can be understood that for those of ordinary skill in the art, equivalent substitutions or changes can be made according to the technical solutions and inventive concepts of the present utility model, and all such changes or substitutions should fall within the protection scope of the present utility model.

Claims

1. Bearingless permanent magnet synchronous motor, characterized in that, It includes a housing, a stator core, a rotor core, and an inner-hole rotating shaft that are sequentially arranged inside the housing from outside to inside; a stator winding is provided on the stator core, the rotor core is sleeved on the inner-hole rotating shaft, and magnets are provided on the rotor core. The housing, the stator core, and the stator winding are combined to form a stator assembly, and the rotor core, the magnets, and the inner-hole rotating shaft are combined to form a rotor assembly. A centrifugal air wheel is provided at the tail end of the inner-hole rotating shaft, and the outer diameter of the centrifugal air wheel is less than or equal to the outer diameter of the rotor assembly. A central perforation with a hole diameter larger than that of the rotor assembly is provided on the housing, and the centrifugal air wheel is located outside the housing; a first keyway extending axially is provided on the inner peripheral wall of the inner-hole rotating shaft.

2. The bearingless permanent magnet synchronous motor according to claim 1, characterized in that, The centrifugal air wheel includes a front annular wheel plate, a rear annular wheel plate, and a plurality of blades arranged in an array and connecting the front annular wheel plate and the rear annular wheel plate. A positioning ring body protrudes from the center of the front end face of the front annular wheel plate. A plurality of mounting holes are arranged around the inner hole of the front annular wheel plate. Threaded holes that are the same in number as and correspond one by one to the mounting holes are provided on the rear end face of the inner-hole rotating shaft. Mounting screws pass through the mounting holes and are connected to the threaded holes.

3. The bearingless permanent magnet synchronous motor according to claim 1, characterized in that, The housing includes a heat dissipation sleeve, a first flange provided at the front end of the heat dissipation sleeve, and a rear cover plate provided at the rear end of the heat dissipation sleeve. The central perforation is provided on the first flange and the rear cover plate.

4. The bearingless permanent magnet synchronous motor according to claim 3, wherein Foot blocks are fixedly provided at the bottom of the heat dissipation sleeve, and lock holes are provided on the foot blocks.

5. The bearingless permanent magnet synchronous motor according to claim 1, wherein A wind cover located outside the centrifugal air wheel is installed at the tail of the housing, and heat dissipation grid holes are provided on the wind cover.

6. The bearingless permanent magnet synchronous motor according to claim 1, wherein, A front rotor pressing plate and a rear rotor pressing plate are respectively provided at the front end and the rear end of the rotor core; a positioning convex ring is provided on the outer peripheral wall of the rear end portion of the inner-hole rotating shaft, and an axially extending second keyway is provided on the outer peripheral wall of the inner-hole rotating shaft. The rotor core is connected to the second keyway of the inner-hole rotating shaft by a key connection method. The rotor core is sleeved on the inner-hole rotating shaft, and the rear end of the rotor core abuts against the positioning convex ring. A clamping groove cooperating with the positioning convex ring is provided on the rear rotor pressing plate.

7. The bearingless permanent magnet synchronous motor according to claim 1, wherein A plurality of tightening screws that are arranged in a circumferential array and penetrate through the rotor core, the front rotor pressing plate, and the rear rotor pressing plate axially are provided on the rotor core. A front tightening nut is threadedly connected to the front end portion of the tightening screw, and a rear tightening nut is threadedly connected to the rear end portion of the tightening screw; the front tightening nut and the rear tightening nut are tightened to clamp the rotor core jointly by the front rotor pressing plate and the rear rotor pressing plate.

8. Screw pump, characterized in that, It includes a bearingless permanent magnet synchronous motor as described in claim 3, a pump body, and a screw rod rotatably connected to the pump body. The rear end of the screw rod is inserted into the inner-hole rotating shaft and is connected to the first keyway of the inner-hole rotating shaft by a key connection method; a second flange is provided at the rear end portion of the pump body, and the first flange and the second flange are connected by docking screws.

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