Fixing structure of permanent magnet motor rotor magnetic steel

Abstract

The utility model provides a fixing structure for rotor magnetic steel of a permanent magnet motor, and belongs to the technical field of motors. The technical problem that how to fix rotor magnetic steel and a rotor shaft of an existing permanent magnet motor is solved. A permanent magnet motor rotor magnetic steel fixing structure comprises a rotor shaft and magnetic steel, the rotor shaft is sleeved with a spacer bush, the spacer bush and the rotor shaft are fixed through a fixing piece, the spacer bush is provided with a plurality of installation through grooves which are evenly distributed in the circumferential direction of the rotor shaft, the magnetic steel is installed in the installation through grooves, the magnetic steel is provided with an inner arc surface, and the inner arc surface is provided with an outer arc surface. The inner arc surface abuts against the outer circumferential surface of the rotor shaft in an attached mode, the spacer bush and the magnetic steel are covered with a sealing layer, and the sealing layer is sleeved with a protective sleeve. According to the utility model, the magnetic steel and the rotor shaft can be better fixed, and the magnetic steel is prevented from falling off when the rotor rotates.

Description

Technical Field

[0001] The utility model belongs to the technical field of motors, in particular to a fixing structure of a permanent magnet motor rotor magnetic steel. Background Art

[0002] The rotor of the motor is the rotating part of the motor. It cooperates with the stator of the motor. When the stator is energized, the rotor rotates to output rotational force. The existing 2-inch deep well pump uses high-speed permanent magnet motors. The industry basically uses asynchronous motors, in which the rotor is cast aluminum. This makes it difficult to improve the efficiency of the motor. The motor is high and heavy. The matching pump body has many impeller stages, resulting in a very high height of the whole machine.

[0003] In order to improve the motor efficiency, reduce the motor height, reduce the weight, and also reduce the height of the whole machine, the 2-inch deep well pump high-speed permanent magnet motor adopts a synchronous motor. However, the rotor of the existing synchronous motor generally includes a rotor and a magnetic steel, and the magnetic steel is fixed to the rotor blank and the shaft. For example, the Chinese patent with the patent number of 2018222072674 and the name of a motor rotor discloses that the magnetic steel of the motor rotor is embedded in the rotor blank, and the shaft is then passed through to fix the rotor blank.

[0004] Since the high-speed permanent magnet motor used in a 2-inch deep well pump is relatively small, the space left for the rotor is even smaller, and there is not much space to set the rotor blank, and the magnet cannot be embedded in the rotor blank for fixation; if a very thin rotor blank is to be set, holes must be dug to embed the magnet, and the rotor blank is difficult to process and is not firm; the prior art also uses glue to fix the magnet, but the rotation speed of the permanent magnet high-speed motor rotor is very fast, and the magnet only attached with glue is easy to fall off; if the fixation is not firm and the magnet falls off, it will cause damage to the motor, affecting the operation and service life of the motor. Summary of the invention

[0005] In view of the shortcomings of the prior art, the utility model provides a permanent magnet motor rotor magnetic steel fixing structure. The technical problem to be solved by the utility model is how to better fix the magnetic steel to the rotor shaft to prevent the magnetic steel from falling off when the rotor rotates.

[0006] The purpose of the utility model can be achieved through the following technical solutions: a permanent magnet motor rotor magnetic steel fixing structure, including a rotor shaft and a magnetic steel, the rotor shaft outer sleeve is provided with a spacer, the spacer and the rotor shaft are fixed by a fixing member, the spacer has a plurality of installation grooves evenly distributed along the circumference of the rotor shaft, the magnetic steel is embedded in the installation grooves, the magnetic steel has an inner arc surface, the inner arc surface is in contact with the outer circumferential surface of the rotor shaft, the spacer and the magnetic steel are covered with a sealing layer, and the sealing layer is provided with a protective sleeve.

[0007] The rotor of the motor is the rotating part of the motor. The rotor cooperates with the stator of the motor. When the stator is powered on, the rotor rotates to output rotational force. This solution is suitable for high-speed permanent magnet motors used in 2-inch deep well pumps. Since the motor has a small diameter, the installation space left for the rotor is also very small, which increases the difficulty of producing the rotor blank for installing the magnetic steel. Therefore, the high-speed permanent magnet motor used in 2-inch deep well pumps does not have a rotor blank to install the magnetic steel, while the permanent magnet synchronous motor rotor must have magnetic steel and the magnetic steel must be firmly fixed. Therefore, a magnet is directly attached to the rotor shaft, and a spacer is arranged outside the rotor shaft to separate and pre-fix the magnets to prevent the magnets from attracting and colliding with each other in the circumferential direction; a number of installation grooves are evenly distributed on the spacer along the circumference of the rotor shaft, and the installation grooves can allow the inner arc surface of the magnet to directly fit and abut against the outer circumferential surface of the rotor shaft, and the installation grooves can also prevent the magnet from falling off in the axial direction and the circumferential direction, and the magnet and the spacer are more firmly sealed and adhered to the outer circumferential surface of the rotor shaft through a sealing layer, and the sealing layer is preferably an epoxy resin layer, and a protective cover is put on the sealing layer before it is cured to make it integrated, so that the magnet will not fall off when the rotor rotates, and the thermal conductivity of the preferred epoxy resin layer can also be used to enhance the heat dissipation capacity of components; this scheme forms a rotor structure that not only does not increase the overall diameter of the rotor but also ensures better fixation of the magnet and the rotor shaft to prevent the magnet from falling off when the rotor rotates.

[0008] In the above-mentioned permanent magnet motor rotor magnetic steel fixing structure, the spacer has a plurality of ribs evenly distributed along the circumference of the rotor shaft and a plurality of closed rings connecting the ribs in sequence, wherein a mounting groove is formed between each two adjacent ribs and two closed rings. The ribs can preferably be 2 to 8, etc., and the ribs are used to separate the magnetic steels so that they will not attract or collide with each other in the circumferential direction.

[0009] In the above-mentioned fixing structure of the permanent magnet motor rotor magnetic steel, there are four ribs, there are two closed rings which are respectively fixed to the two ends of the ribs, there are four mounting grooves, the outer circumferential surface of the rotor shaft is provided with an annular boss which abuts against the end surface of the closed ring, the closed ring is provided with a plurality of through holes evenly distributed along the circumference of the rotor shaft, the rotor shaft is provided with mounting holes opposite to the through holes, and the through holes and the mounting holes are used to set fixing parts to fix the spacer and the rotor shaft.

[0010] This solution provides four mounting through slots for mounting magnets in a one-to-one correspondence, and two adjacent magnets are separated by a rib so that the magnets will not attract or collide with each other in the circumferential direction; the end face of the closed circular ring abuts against the annular boss to position the through hole and the mounting hole so that they correspond to each other, making it convenient to insert rivets for riveting; riveting fixes the spacer sleeve and the rotor shaft with higher strength to prevent the spacer sleeve from rotating in the circumferential direction, and also allows the spacer sleeve to better stabilize the magnets to prevent the magnets from falling off when the rotor rotates, and the fixing piece fixes the spacer sleeve and the rotor shaft to prevent the spacer sleeve from rotating circumferentially.

[0011] In the above-mentioned fixing structure of the permanent magnet motor rotor magnetic steel, the through hole is arranged in the middle of the connection part between the closed ring and the rib, and each closed ring has 4 through holes. The fixing part is a rivet, and the rivet rivets the spacer sleeve and the rotor shaft to fix them. The spacer sleeve and the rotor shaft are riveted and fixed, which is convenient for processing. The fixed spacer sleeve prevents the spacer sleeve from rotating circumferentially.

[0012] This solution sets four through holes and all of them are located in the middle of the connection between the closed ring and the rib. This position is the part with the best rigidity of the spacer. The through holes are opened here to ensure the strength of the spacer and prevent the spacer from breaking, so that the spacer can better stabilize the magnet and prevent the magnet from falling off when the rotor rotates. The four through holes are symmetrically arranged.

[0013] In the above-mentioned permanent magnet motor rotor magnetic steel fixing structure, an annular limiting groove is provided on the rotor shaft along its axial direction, and a retaining spring is arranged in the limiting groove to abut against and fix the outer end surface of the other closed circular ring.

[0014] In the above-mentioned permanent magnet motor rotor magnetic steel fixing structure, the magnetic steel also includes an outer arc surface coaxial with the inner arc surface, two mutually parallel inclined side surfaces are connected between the inner arc surface and the outer arc surface, and two mutually parallel vertical end surfaces are also connected between the inner arc surface and the outer arc surface. The cross section of the rib is wide at the top and narrow at the bottom, and is symmetrical on both sides. The rib has two mutually symmetrical symmetrical inclined surfaces, and the opposite symmetrical inclined surfaces between two adjacent ribs are parallel to each other to form a mounting groove. The mounting groove is convenient for the magnetic steel to be embedded and easy to install.

[0015] In the above-mentioned permanent magnet motor rotor magnet fixing structure, the magnet is gap-matched with the installation slot, and the sealing layer covers the outer circumferential surface composed of the spacer and the magnet and the gap therein. The gap-matching can more conveniently install the magnet, and the sealing layer fills the gap so that the magnet can be better secured in the installation slot, so that the spacer can better secure the magnet and prevent the magnet from falling off when the rotor rotates.

[0016] In the above-mentioned permanent magnet motor rotor magnet fixing structure, the protective sleeve is arranged outside the uncured sealing layer. The magnet is directly attached to the outer peripheral surface of the rotor shaft, and the spacer is used to separate the magnet, and the spacer is fixed with rivets, and then the sealing layer is brushed so that the magnet and the spacer can be firmly attached to the outer ring of the rotor shaft, and finally the sleeve is put on before the sealing layer is cured to make it integrated, so that the magnet and the rotor shaft are better fixed to prevent the magnet from falling off when the rotor rotates.

[0017] In the above-mentioned permanent magnet motor rotor magnetic steel fixing structure, the material of the spacer is plastic, wherein the spacer is preferably made of nylon material among plastics, which has high mechanical strength, good toughness, high tensile and compressive strength, can better fix the magnetic steel, and the spacer is easy to process by integral molding.

[0018] In the above-mentioned permanent magnet motor rotor magnetic steel fixing structure, the material of the protective cover is stainless steel, preferably 304 stainless steel. The stainless steel protective cover is convenient to process, has good strength, and can better fix the magnetic steel, the spacer sleeve and the sealing layer.

[0019] Compared with the prior art, the technical effects of the utility model are:

[0020] 1. Separate the magnets through the installation grooves on the spacer and directly fit them on the outer circumference of the rotor shaft. Fix the spacer with fixing parts, and then seal the layer so that the magnets and the spacer can be firmly attached to the outer ring of the rotor shaft. Finally, put on the protective cover before the sealing layer is cured to make them integrated, so that the magnets and the rotor shaft are better fixed to prevent the magnets from falling off when the rotor rotates.

[0021] 2. The shape of the magnet is a straight-through annular shape composed of an inner arc surface and an outer arc surface. The four magnets just form a circle. The cross-sectional width of the magnet is similar up and down. The installation slot is also set to have a similar cross-sectional width up and down to match the magnet, and the gap between the two is matched. It is easy to install and the gap can be filled with a sealing layer, so that the installation slot can better stabilize the magnet and prevent the magnet from falling off when the rotor rotates.

[0022] 3. The spacer is preferably made of nylon, which has high mechanical strength, good toughness, high tensile and compressive strength, and can better fix the magnetic steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The utility model is a cross-sectional view Figure 1 .

[0024] Figure 2 The utility model is a cross-sectional view Figure 2 .

[0025] Figure 3 The utility model is a cross-sectional view Figure 3 .

[0026] Figure 4 It is a three-dimensional diagram of the spacer sleeve of the utility model.

[0027] Figure 5 It is a three-dimensional diagram of the magnetic steel of the utility model.

[0028] Figure 6 It is a three-dimensional diagram of the utility model with the sealing layer and the protective cover omitted.

[0029] Figure number marking: 1. Rotor shaft; 101. Boss; 102. Mounting hole; 103. Limiting groove; 2. Magnetic steel; 201. Inner arc surface; 202. Outer arc surface; 203. Inclined side surface; 204. Vertical end surface; 3. Spacer; 301. Mounting through groove; 302. Rib; 303. Closed circular ring; 304. Through hole; 305. Symmetrical inclined surface; 4. Sealing layer; 5. Protective cover; 6. Rivet; 7. Retaining spring. DETAILED DESCRIPTION

[0030] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0031] A permanent magnet motor rotor magnetic steel fixing structure comprises a rotor shaft 1 and a magnetic steel 2, a spacer 3 is sleeved on the outer circumference of the rotor shaft 1, the spacer 3 and the rotor shaft 1 are fixed by a fixing piece, the spacer 3 has a plurality of mounting grooves 301 uniformly distributed along the circumference of the rotor shaft 1, the magnetic steel 2 is installed in the mounting grooves 301, the magnetic steel 2 has an inner arc surface 201 that can be fitted with the outer circumferential surface of the rotor shaft 1, the inner arc surface 201 of the magnetic steel 2 is directly fitted on the outer circumferential surface of the rotor shaft 1, the spacer 3 and the magnetic steel 2 are covered with a thin sealing layer 4, and a protective sleeve 5 is provided outside the sealing layer 4. The magnetic steel 2 is directly attached to the rotor shaft 1, and the magnetic steel 2 is separated and pre-fixed by arranging a spacer sleeve 3 outside the rotor shaft 1 to prevent the magnetic steel 2 from attracting and colliding with each other in the circumferential direction; a plurality of installation grooves 301 are evenly distributed on the spacer sleeve 3 along the circumference of the rotor shaft 1, and the installation grooves 301 can make the inner arc surface 201 of the magnetic steel 2 directly fit and abut against the outer peripheral surface of the rotor shaft 1, and the installation grooves 301 can also prevent the magnetic steel 2 from falling off in the axial direction and the circumferential direction, and the magnetic steel 2 and the spacer sleeve 3 are more firmly attached to the outer peripheral surface of the rotor shaft 1 through the sealing layer 4, and the sealing layer 4 is preferably an epoxy resin layer. Before the sealing layer 4 is cured, the protective cover 5 is put on, so that the sealing layer 4 wraps the magnetic steel 2 and the spacer sleeve 3 and integrates them, so that the magnetic steel 2 will not fall off when the rotor rotates, and the thermal conductivity of the epoxy resin can also be used to enhance the heat dissipation capacity of components. The direct fit between the magnet 2 and the rotor shaft 1 and the covering of a relatively thin sealing layer 4 plus a protective cover 5 protect the entire structure, so that the diameter of the entire rotor can be used on a high-speed permanent magnet motor of about 2 inches in size. This structure can also ensure better fixation of the magnet 2 and the rotor shaft 1 to prevent the magnet 2 from falling off when the rotor rotates.

[0032] The spacer 3 may have two or more ribs 302 evenly distributed along the circumference of the rotor shaft 1 , and may have two or more closed rings 303 , which are connected to the ribs 302 in sequence, wherein a mounting groove 301 is formed between every two adjacent ribs 302 and two closed rings 303 .

[0033] The spacer 3 preferably has four ribs 302 evenly distributed along the circumference of the rotor shaft 1, and preferably has two closed rings 303. The closed rings 303 are located at both ends of the four ribs 302 and sequentially connect the ribs 302, wherein an installation slot 301 is formed between every two adjacent ribs 302 and two closed rings 303. The material of the spacer 3 is preferably plastic, and the spacer 3 is preferably nylon material among plastics. Nylon material has high mechanical strength, good toughness, high tensile and compressive strength, and can better fix the magnetic steel 2. The spacer 3 is preferably integrally molded with plastic. The integral molding is convenient for processing, and the plastic material is relatively light, which reduces the weight of the rotor shaft.

[0034] The outer circumferential surface of the rotor shaft 1 has an annular boss 101 that abuts against the end surface of the closed ring 303. The closed ring 303 has a plurality of through holes 304 evenly distributed along the circumference of the rotor shaft 1. The rotor shaft 1 has mounting holes 102 that are opposite to the through holes 304. The through holes 304 and the mounting holes 102 are used to set fixings to fix the spacer 3 and the rotor shaft 1. The fixings may be bolts, screws, rivets, etc.

[0035] Preferably, rivet riveting is used, and the rivet passes through the through hole 304 to the mounting hole 102 and then rivets are made to fix the spacer 3 and the rotor shaft 1. Preferably, a through hole 304 is provided in the middle of the connection between the closed ring 303 and the rib 302, and each closed ring 303 has four through holes 304. An annular limiting groove 103 is provided on the rotor shaft 1 along its axial direction, and a retaining spring 7 is provided in the limiting groove 103 to abut against the outer end surface of the closed ring 303.

[0036] Preferably, four mounting through slots 301 are embedded in the magnets 2 in a one-to-one correspondence, and two adjacent magnets 2 are separated by a rib 302 so that the magnets 2 will not attract or collide with each other in the circumferential direction; the end face of the closed ring 303 abuts against the annular boss 101 to position the through hole 304 and the mounting hole 102 so that they correspond to each other, which facilitates the insertion of the rivet 6 for riveting; the riveting fixes the spacer 3 and the rotor shaft 1 with higher strength, prevents the spacer 3 from rotating in the circumferential direction, and also enables the spacer 3 to better stabilize the magnets 2 to prevent the magnets 2 from falling off when the rotor rotates.

[0037] like Figure 1 , 2 As shown in FIG. 5 , the magnetic steel 2 also includes an outer arc surface 202 coaxial with the inner arc surface 201, two mutually parallel inclined side surfaces 203 are connected between the inner arc surface 201 and the outer arc surface 202, and two mutually parallel vertical end surfaces 204 are also connected between the inner arc surface 201 and the outer arc surface 202. The cross section of the rib 302 is wide at the top and narrow at the bottom, and is symmetrical on both sides. The rib 302 has two mutually symmetrical symmetrical inclined surfaces 305, and the opposite symmetrical inclined surfaces 305 between two adjacent ribs 302 are parallel to each other to form a mounting slot 301. The mounting slot 301 is convenient for the magnetic steel 2 to be embedded and installed.

[0038] The magnetic steel 2 is gap-matched with the installation slot 301, and the sealing layer 4 covers the outer circumferential surface formed by the spacer 3 and the magnetic steel 2 and the gap therein. The gap-matching can more conveniently install the magnetic steel 2, the epoxy resin fills the gap, and the matching of the installation slot 301 and the magnetic steel 2 makes the magnetic steel 2 better stabilized in the installation slot 301, so that the spacer 3 can better stabilize the magnetic steel 2 and prevent the magnetic steel 2 from falling off when the rotor rotates.

[0039] The protective sleeve 5 is sleeved on the uncured sealing layer 4. The protective sleeve 5 is sleeved on the uncured sealing layer 4, and the excess sealing layer 4 can be scraped off, and the remaining sealing layer 4 and the protective sleeve 5 as well as the magnetic steel 2 and the spacer 3 are integrated into one, so that the magnetic steel 2 and the rotor shaft 1 are better fixed to prevent the magnetic steel 2 from falling off when the rotor rotates. The material of the protective sleeve 5 is 304 stainless steel.

[0040] The installation steps are as follows: first, fix the spacer 3 on the rotor shaft 1, then fix the spacer 3 with rivets to prevent the spacer 3 from rotating in the circumferential direction, then embed the magnetic steel 2, and then brush epoxy resin, AB glue, etc. on the outside of the magnetic steel 2 and the spacer 3 to form a sealing layer 4, and finally put on the protective cover 5.

[0041] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope defined by the claims of the present invention.

Claims

1. A permanent magnet motor rotor magnetic steel fixing structure, comprising a rotor shaft (1) and a magnetic steel (2), characterized in that: The rotor shaft (1) is provided with a spacer (3) on its outer sleeve, the spacer (3) and the rotor shaft (1) are fixed by a fixing member, the spacer (3) has a plurality of mounting through grooves (301) uniformly distributed along the circumference of the rotor shaft (1), the magnetic steel (2) is embedded in the mounting through grooves (301), the magnetic steel (2) has an inner arc surface (201), the inner arc surface (201) is in contact with the outer circumferential surface of the rotor shaft (1), the spacer (3) and the magnetic steel (2) are covered with a sealing layer (4), and the sealing layer (4) is provided with a protective sleeve (5) on its outer sleeve.

2. The permanent magnet motor rotor magnetic steel fixing structure according to claim 1, characterized in that: The spacer (3) comprises a plurality of ribs (302) uniformly distributed along the circumference of the rotor shaft (1) and a plurality of closed circular rings (303) sequentially connecting the ribs (302), wherein a mounting through groove (301) is formed between every two adjacent ribs (302) and two closed circular rings (303).

3. The fixing structure of the permanent magnet motor rotor magnetic steel according to claim 2, characterized in that: There are four ribs (302), there are two closed rings (303) which are respectively fixed to the two ends of the ribs (302), there are four mounting grooves (301), the outer circumferential surface of the rotor shaft (1) is provided with an annular boss (101) which abuts against the end surface of the closed ring (303), the closed ring (303) is provided with a plurality of through holes (304) evenly distributed along the circumference of the rotor shaft (1), the rotor shaft (1) is provided with a mounting hole (102) which is opposite to the through hole (304), and the through hole (304) and the mounting hole (102) are used to set a fixing member to fix the spacer (3) and the rotor shaft (1).

4. The permanent magnet motor rotor magnetic steel fixing structure according to claim 3 is characterized in that: The through hole (304) is arranged in the middle of the connection portion between the closed circular ring (303) and the rib (302), and each closed circular ring (303) has four through holes (304). The fixing member is a rivet (6), and the rivet (6) rivets the spacer (3) and the rotor shaft (1) together.

5. The permanent magnet motor rotor magnetic steel fixing structure according to claim 4, characterized in that: An annular limiting groove (103) is provided on the rotor shaft (1) along its axial direction, and a retaining spring (7) is arranged in the limiting groove (103) and abuts against the outer end surface of the closed circular ring (303).

6. A permanent magnet motor rotor magnetic steel fixing structure according to any one of claims 2 to 5, characterized in that: The magnetic steel (2) further comprises an outer arc surface (202) coaxial with the inner arc surface (201); two mutually parallel inclined side surfaces (203) are connected between the inner arc surface (201) and the outer arc surface (202); two mutually parallel vertical end surfaces (204) are also connected between the inner arc surface (201) and the outer arc surface (202); the cross section of the rib (302) is wide at the top and narrow at the bottom, and is symmetrical on both sides; the rib (302) has two mutually symmetrical symmetrical inclined surfaces; the opposite symmetrical inclined surfaces between two adjacent ribs (302) are parallel to each other to form a mounting through groove (301).

7. The permanent magnet motor rotor magnetic steel fixing structure according to claim 6, characterized in that: The magnetic steel (2) is gap-matched with the installation groove (301), and the sealing layer (4) covers the outer circumferential surface formed by the spacer (3) and the magnetic steel (2) as well as the gap therebetween.

8. The permanent magnet motor rotor magnetic steel fixing structure according to claim 7, characterized in that: The protective sleeve (5) is sleeved outside the uncured sealing layer (4).

9. The permanent magnet motor rotor magnetic steel fixing structure according to claim 1, characterized in that: The material of the spacer (3) is plastic.

10. The permanent magnet motor rotor magnetic steel fixing structure according to claim 1, characterized in that: The material of the protective sleeve (5) is stainless steel.

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