Surface-mounted rotor for permanent magnet motor

Abstract

The present invention relates to a surface-mounted rotor for a permanent magnet motor, comprising a rotating shaft, a rotor core and a plurality of permanent magnets, wherein the plurality of permanent magnets are evenly attached to the outer peripheral surface of the rotor core in the circumferential direction, and the rotor core is also provided with a plurality of groups of surface-mounted components matched with the permanent magnets in the circumferential direction, each group of surface-mounted components comprises a pull rod and a pressure block, the pull rod is fixedly arranged on the rotor core, the pressure block is connected to the pull rod by a bolt, and is fixedly arranged on the rotor core, and the pressure block can press down and fix the permanent magnet matched with it while being fixedly arranged, and both sides of each permanent magnet are attached and fixed to the outer peripheral surface of the rotor core by matching with the surface-mounted components. The present invention has a reasonable structure, solves the problem that the traditional rotor adopts a solid core and has a high rotor loss, and the laminated core permanent magnet cannot be assembled and fixed, and has a reliable structure and good processability.

Description

Technical Field

[0001] The invention relates to a rotor structure, in particular to a surface mounted rotor structure for a permanent magnet motor. Background Art

[0002] Permanent magnet motors have permanent magnets installed inside the motor to generate a permanent magnetic field. No additional energy is required for excitation, the stator current is small, and copper loss and rotor iron loss can be effectively reduced. They have the characteristics of high power factor and low loss, and are therefore increasingly widely used in various energy-saving fields.

[0003] The rotor surface-mounted structure is the most commonly used structure for permanent magnet motors. This structure fixes the permanent magnets to the outer surface of the rotor core, and regularly staggers the N and S poles along the circumferential direction to generate a constant magnetic field in space, which interacts with the stator magnetic field to generate torque for energy transfer.

[0004] The fixation of the surface-mounted permanent magnet is the key to the structural design. In the prior art, the rotor usually adopts a solid iron core, threaded holes are drilled on the outer surface of the iron core, and bolts are screwed into the threaded holes to fix the permanent magnets tightly on the iron core. Due to the solid structure of the iron core, this design will generate very large eddy current losses in the iron core, reducing the efficiency of the motor. At the same time, the heat generated increases the temperature of the rotor, affecting the reliable operation of the motor. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a surface-mounted rotor for a permanent magnet motor, including a rotating shaft, a rotor core and a plurality of permanent magnets. The plurality of permanent magnets are evenly attached to the outer circumferential surface of the rotor core along the circumferential direction. The rotor core is also provided with a plurality of groups of surface-mounted components matching the permanent magnets along the circumferential direction. Each group of surface-mounted components includes a pull rod and a pressure block. The pull rod is fixedly arranged on the rotor core. The pressure block is connected to the pull rod by a bolt and is fixedly arranged on the rotor core. The pressure block can press down and fix the permanent magnet matching with it while being fixedly arranged. Both sides of each permanent magnet are fixed to the outer circumferential surface of the rotor core by matching with the surface-mounted components.

[0006] Preferably, the rotor core is provided with a plurality of tie rod grooves along the circumferential direction on its outer circumferential surface, which respectively cooperate with the surface-mounted components. The tie rod grooves are through grooves, that is, the tie rod grooves extend from one end face of the rotor core to the other end face. The shape and size of the tie rod grooves match the tie rod, and the tie rod is extended into the tie rod groove to achieve positioning. A threaded hole 1 is provided at both the front and rear ends of the tie rod, and a bolt 2 passes through the pressure plate and is threadedly engaged with the threaded hole 1. The tie rod is fixedly set on the rotor core. A plurality of threaded holes 2 are provided on the upper end face of the tie rod, which extend through the lower end face. A bolt 1 passes through the pressure block and is threadedly engaged with the threaded hole 2. The pressure block is tightened and set on the rotor core.

[0007] Preferably, each permanent magnet has a fitting arc surface matching the outer contour of the rotor core at the bottom, the permanent magnet has pressure-bearing inclined surfaces on both sides, and the pressure block has downward pressing inclined surfaces matching the pressure-bearing inclined surfaces on both sides. The rotor core is provided with a pulling groove connected to each pull rod groove, and the pulling groove is a through groove, that is, the pulling groove extends from one end face of the rotor core to the other end face, and the lower end of the pressure block has a protrusion extending into the pulling groove, and the pressure block has a limiting step between the downward pressing inclined surface and the protrusion, and the pressure block can be pressed against the outer contour of the rotor core through the limiting step.

[0008] Preferably, several permanent magnets are overlapped in sequence front to back to form a magnetic column extending from one end face of the rotor core to the other end face, that is, several magnetic columns are evenly attached to the outer circumferential surface of the rotor core along the circumferential direction, and there are bonding planes at both the front and rear ends of the pressing block. Multiple pressing blocks can be bonded and overlapped in a column front to back through the bonding plane in the pulling groove, and the magnetic column is fixed by pressing down the multiple pressing blocks.

[0009] Preferably, the rotor core is of a laminated structure, that is, the rotor core is formed by laminating a plurality of silicon steel sheets with a thickness of 0.3-0.5 mm.

[0010] Preferably, rotor end plates are fixedly provided at both the front and rear ends of the rotor core.

[0011] Preferably, the pressing block, bolt one, bolt two and pressing plate are all made of non-magnetic materials.

[0012] Preferably, when the permanent magnet and the pressing block are fixedly arranged on the rotor core, the height of the upper end surface of the permanent magnet is higher than the height of the upper end surface of the pressing block.

[0013] Preferably, the rotor end plate is made of non-magnetic material.

[0014] By means of the above scheme, the present invention has at least the following advantages:

[0015] The rotor core of the technical solution of the present application is a laminated core structure, which isolates the large axial eddy current path of the core, greatly reduces eddy current losses, improves motor efficiency, and can reduce rotor temperature.

[0016] However, since the iron core is made of stacked thin silicon steel sheets, threaded holes can no longer be drilled on the outer surface of the iron core, and conventional fixing solutions can no longer be used. Therefore, the rotor core of the technical solution of this application adopts a special structural design, that is, the magnets are fixed to the laminated core by using pull rods and pressure blocks placed inside the rotor core, which solves the problem that the surface magnets of the laminated core are difficult to fix.

[0017] The invention solves the problem that the traditional rotor adopts a solid iron core and has high rotor loss, and the laminated iron core permanent magnet cannot be assembled and fixed, and has a reliable structure and good processability.

[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show a certain embodiment of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the surface-mounted rotor for the permanent magnet motor of the present invention;

[0021] Figure 2 It is a schematic diagram of the three-dimensional structure of the surface-mounted rotor for the permanent magnet motor of the present invention without the rotating shaft 1;

[0022] Figure 3 It is a schematic diagram of the structural relationship between the rotor core 2 and the permanent magnet 3 of the surface-mounted rotor for the permanent magnet motor of the present invention;

[0023] Figure 4 It is a schematic diagram of the structural relationship between the rotor core 2, the permanent magnet 3 and the pressing block 5 of the surface-mounted rotor for the permanent magnet motor of the present invention;

[0024] Figure 5 It is a schematic diagram of the structural relationship between the permanent magnet 3, the pull rod 4, and the pressing block 5 of the surface-mounted rotor for the permanent magnet motor of the present invention;

[0025] Figure 6 It is a schematic diagram of the structural relationship between the pull rod 4 and the pressing block 5 of the surface-mounted rotor for the permanent magnet motor of the present invention;

[0026] Figure 7 It is a three-dimensional structural schematic diagram of the pull rod 4 of the surface-mounted rotor for the permanent magnet motor of the present invention;

[0027] Figure 8 It is a schematic diagram of the three-dimensional structure of the permanent magnet 3 of the surface-mounted rotor for the permanent magnet motor of the present invention.

[0028] In the figure: shaft 1, rotor core 2, permanent magnet 3, pull rod 4, pressure block 5, bolt 1 6, pull rod groove 7, threaded hole 1 8, bolt 2 9, pressure plate 10, threaded hole 2 11, fitting arc surface 12, pressure-bearing inclined surface 13, downward pressing inclined surface 14, lifting groove 15, protrusion 16, limiting step 17, fitting plane 18, rotor end plate 19. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0030] See also Figure 1 to Figure 8 A surface-mounted rotor for a permanent magnet motor according to a preferred embodiment of the present invention comprises a rotating shaft 1, a rotor core 2 and a plurality of permanent magnets 3, wherein the plurality of permanent magnets 3 are evenly attached to the outer peripheral surface of the rotor core 2 along the circumferential direction, and the rotor core 2 is also provided with a plurality of groups of surface-mounted components matched with the permanent magnets 3 along the circumferential direction, each group of surface-mounted components comprises a tie rod 4 and a pressure block 5, the tie rod 4 is fixedly arranged on the rotor core 2, the pressure block 5 is connected to the tie rod 4 by a bolt 6, and is fixedly arranged on the rotor core 2, and the pressure block 5 can press down and fix the permanent magnet 3 matched with it while being fixedly arranged, and both sides of each permanent magnet 3 are attached and fixed to the outer peripheral surface of the rotor core 2 by matching with the surface-mounted components. With the above structure, it is not necessary to adopt the installation method of directly fixing the permanent magnet 3 on the rotor core 2 with screws, so the rotor core 2 can adopt a laminated structure.

[0031] Preferably, the rotor core 2 is provided with a plurality of tie rod grooves 7 along the circumferential direction on its outer circumferential surface, which are respectively matched with the surface-mounted components. The tie rod grooves 7 are through grooves, that is, the tie rod grooves 7 extend from one end face of the rotor core 2 to the other end face. The shape and size of the tie rod grooves 7 match the tie rod 4. The tie rod 4 is extended into the tie rod grooves 7 to achieve positioning. Threaded holes 8 are provided at the front and rear ends of the tie rod 4. Bolts 9 pass through the pressure plate 10 and are threadedly matched with the threaded holes 8. The tie rod 4 is fixedly set on the rotor core 2. A plurality of threaded holes 11 are provided on the upper end face of the tie rod 4 and extend through the pressure block 5 to be threadedly matched with the threaded holes 11. The pressure block 5 is tightened and set on the rotor core 2. The present invention adopts the pull rod 4 and the pressure block 5 to be tightened together, so that the pressure block 5 presses down and fixes the permanent magnet 3. This method does not require drilling holes on the permanent magnet 3, and can facilitate the processing and manufacturing of the rotor core 2. The pull rod 4 and the pressure block 5 are used for opening holes and matching bolts, which can maximize the purpose of not affecting the normal use of the rotor.

[0032] Preferably, each permanent magnet 3 has a fitting arc surface 12 matching the outer contour of the rotor core 2 at the bottom, and the permanent magnet 3 has pressure-bearing inclined surfaces 13 on both sides. The pressure block 5 has downward pressing inclined surfaces 14 matching the pressure-bearing inclined surfaces 13 on both sides. The rotor core 2 has a pulling groove 15 connected to each pull rod groove 7. The pulling groove 15 is a through groove, that is, the pulling groove 15 extends from one end face of the rotor core 2 to the other end face. The lower end of the pressure block 5 has a protrusion 16 extending into the pulling groove 15. The pressure block 5 has a limiting step 17 between the downward pressing inclined surface 14 and the protrusion 16. The pressure block 5 can be pressed against the outer contour of the rotor core 2 through the limiting step 17. By fitting the arc surface 12, each permanent magnet 3 can be better fitted on the outer contour of the rotor core 2, which facilitates the pressing and fixing of the pressure block 5. By means of the protrusion 16, the pressure block 5 can be fixedly set on the rotor core 2 while achieving its own limiting purpose to avoid displacement in the circumferential direction of the rotor core 2. By the cooperation of the downward pressing inclined surface 14 and the inclined surface of the pressure-bearing inclined surface 13, each permanent magnet 3 can be reliably pressed and fixed on the outer contour of the rotor core 2 through the pressure blocks 5 on the adjacent two sides.

[0033] Preferably, several permanent magnets 3 overlap in sequence front and back to form a magnetic column extending from one end face of the rotor core 2 to the other end face, that is, several magnetic columns are evenly attached to the outer peripheral surface of the rotor core 2 along the circumferential direction, and the front and rear ends of the pressing block 5 have a fitting plane 18. Multiple pressing blocks 5 can be fitted and overlapped in a column in the pulling groove 15 through the fitting plane 18, and the magnetic column is fixed by pressing down multiple pressing blocks 5. For better use effect and convenient installation and manufacturing, multiple permanent magnets 3 can be arranged front and back, and each pressing block 5 can cooperate with several permanent magnets 3 of corresponding length, and multiple pressing blocks 5 are arranged front and back to meet the use requirements.

[0034] Preferably, the rotor core 2 is a laminated structure, that is, the rotor core 2 is formed by laminating a plurality of silicon steel sheets with a thickness of 0.3-0.5 mm.

[0035] Preferably, rotor end plates 19 are fixedly provided at both the front and rear ends of the rotor core 2 .

[0036] Preferably, the pressing block 5, the bolt 1 6, the bolt 2 9, and the pressing plate 10 are all made of non-magnetic conductive materials, thereby effectively preventing the occurrence of short-circuit magnetic leakage.

[0037] Preferably, when the permanent magnet 3 and the pressing block 5 are fixedly arranged on the rotor core 2 , the height of the upper end surface of the permanent magnet 3 is higher than the height of the upper end surface of the pressing block 5 .

[0038] Preferably, the rotor end plate 19 is made of non-magnetic conductive material, which is also used to prevent the occurrence of short circuit magnetic leakage.

[0039] After the rotor structure of the technical solution of the present application is assembled, the permanent magnet 3 can be firmly fixed on the surface of the rotor core 2. The permanent magnet 3 is effectively fixed in radial, axial and circumferential directions, and will not be displaced in any direction due to force, so the torque can be reliably transmitted.

[0040] Furthermore, compared with the prior art, the advantages and progress of the technical solution of this application are also very obvious:

[0041] Taking a 132kW, 380V, 140rpm variable frequency permanent magnet synchronous motor as an example, the electromagnetic calculation parameters of the traditional rotor and the patented rotor are compared in Table 1.

[0042] Comparison Items Conventional rotor This application rotor Output power kW 132.6 132.6 Line voltage effective value V 380.4 380.4 Line current effective value A 225 225 Frequency Hz 28 28 Speed ​​rpm 140 140 Torque ripple % 1.80 1.45 Rotor iron loss kW 0.5136 0.0389 Total loss kW 5.685 5.208 efficiency% 95.88 96.23 Rotor maximum temperature ℃ 92.6 82.5

[0043] It can be seen from Table 1 that when the motor input parameters are equivalent, the rotor core loss of 0.0389kW of the technical solution of the present application is much lower than the iron loss of 0.5136kW generated by the traditional rotor, and the iron loss is reduced by 92.4%. The overall efficiency of the motor is 96.23% compared to 95.88%, which is an increase of 0.35%. The temperature is 82.5℃, which is 10.1℃ lower than 92.6℃. At the same time, the torque pulsation is reduced, which can also reduce the vibration amplitude of the motor and improve the reliability of the motor.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A surface-mounted rotor for a permanent magnet motor, comprising a rotating shaft (1), a rotor core (2) and a plurality of permanent magnets (3), characterized in that: A plurality of permanent magnets (3) are evenly attached to the outer peripheral surface of the rotor core (2) along the circumferential direction. The rotor core (2) is also provided with a plurality of groups of surface-attached components that match the permanent magnets (3) along the circumferential direction. Each group of surface-attached components comprises a pull rod (4) and a pressure block (5). The pull rod (4) is fixedly arranged on the rotor core (2). The pressure block (5) is connected to the pull rod (4) by a bolt (6) and is fixedly arranged on the rotor core (2). The pressure block (5) can press down and fix the permanent magnet (3) that matches with it while being fixedly arranged. Both sides of each permanent magnet (3) are attached and fixed to the outer peripheral surface of the rotor core (2) by matching with the surface-attached components. The rotor core (2) is provided with a plurality of tie rod grooves (7) along the circumferential direction on its outer circumferential surface, which are respectively matched with the surface-mounted components. The tie rod groove (7) is a through groove, that is, the tie rod groove (7) extends from one end face of the rotor core (2) to the other end face. The shape and size of the tie rod groove (7) match the tie rod (4). The tie rod (4) is extended into the tie rod groove (7) to achieve position limiting. The front and rear ends of the tie rod (4) are provided with a threaded hole (8). A bolt (9) passes through the pressure plate (10) and is threadedly matched with the threaded hole (8). The tie rod (4) is fixedly arranged on the rotor core (2). The upper end face of the tie rod (4) is provided with a plurality of threaded holes (11) extending through to the lower end face. A bolt (6) passes through the pressure block (5) and is threadedly matched with the threaded hole (11). The pressure block (5) is tensioned and arranged on the rotor core (2).

2. The surface-mounted rotor for a permanent magnet motor according to claim 1, characterized in that: Each permanent magnet (3) has a fitting arc surface (12) matching the outer contour of the rotor core (2) at its bottom, and the permanent magnet (3) has pressure-bearing inclined surfaces (13) on both sides. The pressure block (5) has downward pressure inclined surfaces (14) matching the pressure-bearing inclined surfaces (13) on both sides. The rotor core (2) has a pulling groove (15) connected to each pull rod groove (7) at each pull rod groove (7). The pulling groove (15) is a through groove, that is, the pulling groove (15) extends from one end face of the rotor core (2) to the other end face. The lower end of the pressure block (5) has a protrusion (16) extending into the pulling groove (15). The pressure block (5) has a limiting step (17) between the downward pressure inclined surface (14) and the protrusion (16). The pressure block (5) can be pressed against the outer contour of the rotor core (2) through the limiting step (17).

3. The surface-mounted rotor for a permanent magnet motor according to claim 2, characterized in that: A plurality of permanent magnets (3) are overlapped in sequence in front and back to form a magnetic array extending from one end face of the rotor core (2) to the other end face, that is, a plurality of magnetic arrays are evenly attached to the outer peripheral surface of the rotor core (2) along the circumferential direction. Both the front and rear ends of the pressing block (5) have affixed planes (18). A plurality of pressing blocks (5) can be attached in front and back in the pulling groove (15) through the affixed planes (18) and overlapped in an array, and the magnetic array is fixed by pressing down the plurality of pressing blocks (5).

4. The surface-mounted rotor for a permanent magnet motor according to claim 1, characterized in that: The rotor core (2) is of a laminated structure, that is, the rotor core (2) is formed by laminating a plurality of silicon steel sheets with a thickness of 0.3 to 0.5 mm.

5. The surface-mounted rotor for a permanent magnet motor according to claim 1, characterized in that: Rotor end plates (19) are fixedly arranged at both the front and rear ends of the rotor core (2).

6. The surface-mounted rotor for a permanent magnet motor according to claim 1, characterized in that: The pressing block (5), bolt one (6), bolt two (9) and pressing plate (10) are all made of non-magnetic conductive materials.

7. The surface-mounted rotor for a permanent magnet motor according to claim 1, characterized in that: When the permanent magnet (3) and the pressing block (5) are fixedly arranged on the rotor core (2), the height of the upper end surface of the permanent magnet (3) is higher than the height of the upper end surface of the pressing block (5).

8. The surface-mounted rotor for a permanent magnet motor according to claim 5, characterized in that: The rotor end plate (19) is made of non-magnetic conductive material.

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