Permanent magnet motor rotor, assembling method and submersible motor

Abstract

The invention belongs to the field of motors, particularly relates to a permanent magnet motor rotor, an assembling method and a submersible motor, and aims to solve the problems that an existing segmented permanent magnet is poor in magnetic attraction force overall strength and large in eddy current loss. The permanent magnet motor rotor comprises magnetic steel, rivets, rotor pieces and baffles, the magnetic steel and the rotor pieces are fixedly connected, and every two adjacent magnetic steel are arranged in a V shape; the baffles are fixedly arranged at the two ends of the rotor piece, riveting holes are formed in the rotor piece and the baffles in the axis direction, the rivets can penetrate through the riveting holes and rivet the rotor piece and the baffles at the two ends, the V-shaped magnetic steel structure is adopted, eddy current loss can be reduced, and the mechanical strength of the rotor joint is improved.

Description

Technical Field

[0001] This invention belongs to the field of electric motors, and specifically relates to a permanent magnet motor rotor, an assembly method, and a submersible motor. Background Technology

[0002] Submersible electric pumps (SAPs) are highly efficient oilfield extraction equipment, and their submersible motors are the power source of the oil production system and a major energy-consuming component. Their performance directly affects the quality and lifespan of the unit and even the oil well, and also directly impacts crude oil production and various oil production costs. Submersible asynchronous motors, used for power extraction, suffer from high power consumption and low efficiency, severely impacting the economic benefits of oilfield extraction. Compared to submersible asynchronous motors, submersible permanent magnet synchronous motors (PMSMs) offer advantages such as high efficiency, high power factor, and no need for excitation. They align with the development concepts of environmental protection, energy conservation, and reduced consumption, and represent the future development direction for submersible motors.

[0003] The permanent magnet submersible motor has a slender structure, and its structural design is greatly affected by space constraints. The design, processing and assembly of the permanent magnet rotor is the most difficult process in the manufacturing process. The existing segmented permanent magnets have poor overall magnetic attraction strength and large eddy current losses. The submersible permanent magnet motor rotor has the problem of magnet demagnetization due to temperature, which affects the service life of the unit. Summary of the Invention

[0004] To address the problem of magnet demagnetization due to temperature in the rotor of a submersible permanent magnet motor in the prior art, some embodiments of the present invention provide a permanent magnet motor rotor, including magnets, rivets, rotor plates, and baffles;

[0005] The magnets are fixedly connected to the rotor plates, and two adjacent magnets are arranged in a V-shape. The baffles are fixedly disposed at both ends of the rotor plates. The rotor plates and the baffles have riveting holes along the axial direction inside. The rivets can pass through the riveting holes and rivet the rotor plates and the baffles at both ends.

[0006] According to some embodiments of this application, a permanent magnet motor rotor is provided, wherein the rivet is a non-magnetic stainless steel guide bar rivet.

[0007] According to some embodiments of this application, a permanent magnet motor rotor is provided, wherein the rotor plate has a rotor inner hole in the middle, and the side wall of the rotor inner hole is provided with a keyway, wherein at least three keyways are provided and the three keyways are spaced apart.

[0008] According to some embodiments of this application, a permanent magnet motor rotor is provided, wherein the keyway includes a first keyway, a second keyway and a third keyway, and the first keyway, the second keyway and the third keyway are distributed along the circumferential direction of the inner hole of the rotor.

[0009] On the other hand, some embodiments of this application also provide a permanent magnet submersible motor, including the aforementioned permanent magnet motor rotor, and further including a motor shaft, a retaining ring assembly, a rotor key, and a bearing assembly; the rotor key is coaxially mounted outside the motor shaft, the rotor is disposed outside the rotor key, the bearing assembly is sleeved on the motor shaft, and the retaining ring assembly is disposed near the bearing assembly.

[0010] According to some embodiments of this application, a permanent magnet submersible motor is provided, wherein the bearing assembly includes a plurality of bearings, the bearings being disposed at the ends near the rotor key.

[0011] According to some embodiments of this application, a permanent magnet submersible motor is provided, wherein the retaining ring assembly includes a first retaining ring and a second retaining ring, the first retaining ring and the second retaining ring being respectively disposed on the opposite side of the bearing and the rotor key.

[0012] On the other hand, some embodiments of this application also provide a rotor assembly method for a permanent magnet motor rotor, comprising the following steps: S1, assembling a first rotor section and inserting it into the motor shaft using a first keyway; S2, assembling a second rotor section and inserting it into the motor shaft using a second keyway; S3, assembling a third rotor section and inserting it into the motor shaft using a third keyway; S4, repeating S1-S3 sequentially to complete the assembly of the rotor assembly.

[0013] The beneficial effects of this invention are:

[0014] The V-shaped magnet structure improves the stability of the segmented permanent magnets, reduces electromagnetic vibration and noise, and ensures accurate magnetic field distribution after rotor assembly, thus reducing eddy current losses.

[0015] By using a dual fixing method of setting baffles and pressing them, and setting rivets for riveting, the problem of poor overall strength of the segmented permanent magnet magnetic attraction is solved, and the mechanical strength of the rotor section is improved. According to the rotor magnetic field distribution diagram, the magnetic circuit channel of the permanent magnet rotor is avoided, holes are opened inside the magnetic poles, and non-magnetic stainless steel guide bars are selected for riveting to reduce eddy current losses.

[0016] This invention solves the problems of rotor mechanical strength, manufacturing and assembly of permanent magnet motor rotors through rotor design and rotor assembly process, and eliminates the problem of accelerated insulation aging of motor caused by irreversible demagnetization of permanent magnets, thereby extending the service life of permanent magnet motors and improving efficiency. Attached Figure Description

[0017] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0018] Figure 1 These are schematic diagrams of rotor structures according to some embodiments of this application;

[0019] Figure 2 These are schematic diagrams of the magnetic steel structure of some embodiments of this application;

[0020] Figure 3 This is a schematic diagram showing the positions of the baffle and rivets in some embodiments of this application.

[0021] In the diagram: 1. Magnet; 2. Rivet; 3. Rotor plate; 4. Baffle; 5. Rotor inner hole; 6. Keyway; 61. First keyway; 62. Second keyway; 63. Third keyway; 7. Motor shaft; 81. First retaining ring; 82. Second retaining ring; 9. Rotor key; 10. Bearing assembly; 11. Rotor. Detailed Implementation

[0022] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] like Figure 1-3 As shown, some embodiments of the present invention provide a permanent magnet motor rotor, including a magnet 1, a rivet 2, rotor plates 3, and a baffle 4;

[0025] Magnet 1 is fixedly connected to rotor plate 3. Two adjacent magnets 1 are arranged in a V-shape. Baffle 4 is fixedly set at both ends of rotor plate 3. Riveting holes are opened inside rotor plate 3 and baffle 4 along the axial direction. Rivet 2 can pass through the riveting holes and rivet the rotor plate and the baffle 4 at both ends. Rivet 2 is a non-magnetic stainless steel guide bar riveting.

[0026] In specific implementation, the rotor 11 includes a magnet 1, a rivet 2, rotor plates 3, and a baffle 4. It adopts a "guide bar riveting-end clamping" rotor structure. Specifically, first, the rotor plates 3 are inserted into the mandrel fixture, one side baffle 4 is installed, the magnet 1 is installed, then the other side baffle 4 is installed and the baffle is clamped. Finally, the rivets 2 are used to rivet it.

[0027] like Figure 2 As shown, the included angle between the two magnets on the same side is close to 160 degrees, and the whole is set in a V shape. There are at least four rivet holes and rivets 2, and the four rivets 2 are distributed at intervals in the circumferential direction of the rotor inner hole 5.

[0028] By analyzing the rotor strength through finite element three-dimensional stress analysis and the influence of centrifugal force during high-speed rotation of magnet 1, a V-shaped built-in embedded magnet structure was designed to improve the stability of segmented permanent magnets. A dual fixing method of "guide bar riveting - end clamping" was adopted to solve the problem of poor overall strength of magnetic attraction force of segmented permanent magnets and improve the mechanical strength of rotor sections. According to the rotor magnetic field distribution diagram, the magnetic circuit channel of permanent magnet rotor was avoided. Holes were opened inside the magnetic poles and non-magnetic stainless steel guide bars were selected for riveting to reduce eddy current losses.

[0029] In some embodiments, a rotor inner hole 5 is provided in the middle of the rotor plate 3, and a keyway 6 is provided on the side wall of the rotor inner hole 5. At least three keyways 6 are provided, and the three keyways 6 are distributed at intervals. The keyway 6 includes a first keyway 61, a second keyway 62 and a third keyway 63, and the first keyway 61, the second keyway 62 and the third keyway 63 are distributed along the circumferential direction of the rotor inner hole 5.

[0030] In practice, a permanent magnet segmented skew pole assembly process was adopted. The rotor inner hole 5 is designed with three keyways 6, and the adjacent keyways are distributed at an angle of nearly 90 degrees.

[0031] In some embodiments, this application also provides a permanent magnet submersible motor, including a permanent magnet motor rotor, and further including a motor shaft 7, a retaining ring assembly, a rotor key 9, and a bearing assembly 10; the rotor key 9 is coaxially mounted outside the motor shaft 7, the rotor is disposed outside the rotor key 9, the bearing assembly 10 is sleeved on the motor shaft 7, and the retaining ring assembly is disposed near the bearing assembly 10. Specifically, the bearing assembly 10 includes multiple bearings, such as... Figure 1 As shown, the bearing is located near the end of the rotor key 9. The retaining ring assembly includes a first retaining ring 81 and a second retaining ring 82, which are respectively located on the opposite side of the bearing and the rotor key 9.

[0032] In practice, rotor key 9 sequentially fixes the second retaining ring 82, bearing assembly 10, rotor 11, and first retaining ring 81 to the motor shaft 7. The rotor 11 employs a "V"-shaped magnet structure to improve the stability of the segmented permanent magnets and reduce electromagnetic vibration and noise. A "guide bar riveting-end clamping" rotor structure is used, and each rotor is assembled onto the motor shaft 7 in a specific order using a segmented, skewed pole assembly method. Accurate magnetic field distribution is ensured by detecting the strong unipolar magnetism of the permanent magnet rotor.

[0033] In some embodiments, this application also provides a rotor assembly method for a permanent magnet motor rotor, comprising the following steps: S1, assembling a first rotor section by inserting a first keyway 61 into the motor shaft; S2, assembling a second rotor section by inserting a second keyway 62 into the motor shaft; S3, assembling a third rotor section by inserting a third keyway 63 into the motor shaft; S4, repeating S1-S3 sequentially to complete the assembly of the rotor assembly.

[0034] In practice, a permanent magnet segmented skewed pole assembly process was adopted. The rotor inner hole 5 is designed with three keyways 6. When assembling the first rotor section, the first keyway 61 is used to insert it into the motor shaft. When assembling the second rotor section, the second keyway 62 is used to insert it into the motor shaft. When assembling the third rotor section, the third keyway 63 is used to insert it into the motor shaft. The rotor assembly is completed in a cyclical manner according to the above assembly method. After the rotor is assembled, the magnetic pole polarity of each rotor section should be consistent to ensure accurate magnetic field distribution. This design can reduce eddy current losses.

[0035] In the description of this invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate direction or positional relationships, are based on the direction or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0038] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A permanent magnet motor rotor, characterized in that, It includes magnets (1), rivets (2), rotor plates (3), and baffles (4); The magnet (1) is fixedly connected to the rotor plate (3), and two adjacent magnets (1) are arranged in a V-shape. The baffle (4) is fixedly installed at both ends of the rotor plate (3). The rotor plate (3) and the baffle (4) have riveting holes opened in the axial direction. The rivet (2) can pass through the riveting holes and rivet the rotor plate and the baffle (4) at both ends.

2. A permanent magnet motor rotor according to claim 1, characterized in that, The rivet (2) is a non-magnetic stainless steel guide bar rivet.

3. A permanent magnet motor rotor according to claim 2, characterized in that, The rotor plate (3) has a rotor inner hole (5) in the middle, and a keyway (6) is provided on the side wall of the rotor inner hole (5). At least three keyways (6) are provided, and the three keyways (6) are distributed at intervals.

4. A permanent magnet motor rotor according to claim 3, characterized in that, The keyway (6) includes a first keyway (61), a second keyway (62) and a third keyway (63), which are distributed along the circumferential direction of the rotor inner hole (5).

5. A permanent magnet submersible motor, comprising a permanent magnet motor rotor as described in any one of claims 3-4, characterized in that, It also includes a motor shaft (7), a retaining ring assembly, a rotor key (9), and a bearing assembly (10); The rotor key (9) is coaxially mounted outside the motor shaft (7), the rotor is located outside the rotor key (9), the bearing assembly (10) is sleeved on the motor shaft (7), and the retaining ring assembly is located near the bearing assembly (10).

6. A permanent magnet submersible motor according to claim 5, characterized in that, The bearing assembly (10) includes a plurality of bearings disposed near the end of the rotor key (9).

7. A permanent magnet submersible motor according to claim 6, characterized in that, The retaining ring assembly includes a first retaining ring (81) and a second retaining ring (82), which are respectively disposed on the opposite side of the bearing and the rotor key (9).

8. A rotor assembly method for a permanent magnet motor rotor as described in any one of claims 6-7, characterized in that, Includes the following steps: S1. Assemble the first rotor section and insert it into the motor shaft using the first keyway (61); S2. Assemble the second rotor section and insert it into the motor shaft using the second keyway (62); S3. Assemble the third rotor section and insert it into the motor shaft using the third keyway (63); S4. Repeat S1-S3 sequentially to complete the assembly of the rotor assembly.

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