A large-torque low-speed submersible permanent magnet motor

Abstract

This invention discloses a high-torque, low-speed submersible permanent magnet motor, belonging to the technical field of oil production equipment. It includes a tailstock cap, a motor base, a motor housing, a motor head, a transport cap, a centering bearing, a rotor, a drive shaft, and a stator. The motor housing has the motor head and motor base connected to its two ends respectively. The transport cap and tailstock cap are respectively installed on the outer ends of the motor head and motor base. The stator is installed in the motor housing, and the drive shaft is also installed in the motor housing. Both ends of the drive shaft are inserted into the motor head and motor base, and the drive shaft is located inside the stator. Several rotors are installed on the outer side of the drive shaft, and several centering bearings are also installed on the outer side of the drive shaft. The centering bearings are located between two rotors or on the outer side of the rotors, and are located inside the stator. This invention solves the problem of low oil production efficiency caused by the low torque and insufficient power of existing three-phase asynchronous submersible motors in small-diameter wells. It also improves the versatility of the motor.

Description

Technical Field

[0001] This invention relates to the field of oil production equipment technology, specifically to a high-torque, low-speed submersible permanent magnet motor. Background Technology

[0002] Currently, in traditional oilfield formations, most rodless manual lifting methods in heavy oil wells and coalbed methane wells employ electric submersible screw pumps. However, in scenarios with smaller casing diameters, such as small-diameter wellbores with a casing diameter of 4.5 inches, small-diameter units are required. Traditional units use a three-phase asynchronous submersible motor connected to a reducer to drive the screw pump. Due to the relatively small diameter of the reducer, the transmitted torque is very limited, which cannot meet the power requirements of the screw pump and therefore cannot provide a high-lift, large-displacement manual lifting solution.

[0003] Therefore, how to provide a high-torque, low-speed submersible permanent magnet motor to solve the defects of existing oil production structures is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To address this issue, the present invention provides a high-torque, low-speed submersible permanent magnet motor to solve the problem of low oil production efficiency caused by the small torque and insufficient power of three-phase asynchronous submersible motors in small-diameter wells in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention discloses a high-torque, low-speed submersible permanent magnet motor, comprising: The motor housing has a motor head and a motor base connected to its two ends, and a transport cap and a tail cap are respectively installed on the outer ends of the motor head and the motor base. The stator is installed in the motor housing; A drive shaft is installed in the motor housing, with both ends of the drive shaft inserted into the motor head and the motor base, and the drive shaft is located inside the stator; Several rotors are mounted on the outside of the drive shaft. Several straightening bearings are also mounted on the outside of the drive shaft. The straightening bearings are located between two rotors or on the outside of the rotors. The straightening bearings and rotors are located on the inside of the stator.

[0006] In one possible implementation, the motor base includes: The connector has a connecting hole inside, the bottom end of the drive shaft is set in the connecting hole, the bottom of the connector has an insertion hole, the insertion hole is connected to the connecting hole, and the tailstock cap is inserted into the insertion hole; A first connecting seat is provided on the side wall of the connector. A one-way valve is installed in the first connecting seat. An oil inlet channel is also provided in the connector. The top of the oil inlet channel is connected to the inside of the motor housing. A first thread is formed on the outside of the connector, and the first thread is located above the first connector. A first limiting ring is installed in the connector, and a second limiting ring is installed inside the first limiting ring. The second limiting ring is sleeved on the outside of the bottom end of the drive shaft.

[0007] In one possible implementation, the motor head includes: The mounting component has an internal mounting hole, the upper end of the drive shaft is disposed in the mounting hole, the top end of the drive shaft is disposed in the transport cap, and the outer side of the mounting component is provided with a second thread; A second connecting seat is provided on the side wall of the mounting component, and a one-way valve is installed in the second connecting seat; Two limiting components are provided and installed in the mounting holes. A thrust bearing is also installed in the mounting holes and is sleeved on the outside of the drive shaft. A lead hole is provided on the side of the mounting component, and a lead wire cover is inserted at the end of the lead hole.

[0008] In one possible implementation, the drive shaft includes: The shaft has a round hole in the middle; The limiting members are arranged in pairs and installed on the outside of the shaft body, and the limiting members abut against the outside of the straightening bearing.

[0009] In one possible implementation, the centering bearing includes: The bearing housing has a ring-shaped structure, and a bearing sleeve is rotatably connected to the inner surface of the bearing housing. The bearing sleeve is fitted onto the outside of the transmission shaft. Several oil passage holes are formed on the bearing housing, and an annular limiting plate is installed on the outer side of the bearing housing; A mounting hole for the limiting component is formed on the annular limiting plate and extends into the bearing housing; A limiting spring is installed at one end in the mounting hole of the limiting component, and an L-shaped limiting tab is installed at the other end of the limiting spring. The outer end of the L-shaped limiting tab abuts against the inner wall of the annular limiting plate. The top plate is installed on the outside of the L-shaped limiting lever.

[0010] In one possible implementation, a permanent magnet layer is attached to the outer surface of the rotor, a spacer plate is connected to the end of the rotor, a slot is provided in the rotor, and a rectangular hole is opened on the side wall of the slot.

[0011] In one possible implementation, the stator is constructed using stator laminations, the stator laminations having a closed slot structure, and the stator is connected to a stator end plate and an insulating end plate.

[0012] In one possible implementation, the transport cap is provided with a positioning shaft and a spline sleeve, one end of which is sleeved on the outside of the drive shaft, and the positioning shaft is inserted into the other end of the spline sleeve.

[0013] This invention eliminates the speed reducer and increases torque by using a multi-stage rotor to increase the air gap magnetic field density. This configuration can replace a three-phase asynchronous motor and is suitable for use in oil extraction environments with small boreholes and high displacement requirements. At the same time, the self-lubricating centering bearing increases the radial load-bearing capacity of the structure itself, thereby increasing the service life of the structure. Moreover, the multi-stage drive method reduces the drive current compared to a single drive, making the entire device more energy-efficient. Furthermore, this design is more suitable for deep crude oil extraction environments. Attached Figure Description

[0014] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0015] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0016] Figure 1 A three-dimensional view of a high-torque, low-speed submersible permanent magnet motor provided for this invention; Figure 2 Cross-sectional views of the straightening bearing, rotor, drive shaft, and stator provided for this invention; Figure 3 A cross-sectional view of the motor base provided for this invention; Figure 4 A cross-sectional view of the motor head provided by the present invention; Figure 5 A perspective view of the drive shaft provided by the present invention; Figure 6 A perspective view of the straightening bearing provided for this invention; Figure 7 Provided by the present invention Figure 6 Enlarged view of a portion of point A in the middle; Figure 8 A perspective view of the rotor provided for this invention; In the diagram: 1. Tailstock cap; 2. Motor base; 21. Connector; 22. First connecting seat; 23. Oil inlet channel; 24. Second limiting ring; 25. First limiting ring; 26. First thread; 3. Motor housing; 4. Motor head; 41. Limiting component; 42. Second thread; 43. Second connecting seat; 44. Thrust bearing; 45. Mounting component; 46. Mounting hole; 47. Lead wire cover; 5. Transport cap; 51. Spline sleeve; 52. Positioning shaft; 6. Centering bearing; 61. Bearing seat; 62. Annular limiting plate; 63. Bearing sleeve; 64. Oil passage hole; 66. L-shaped limiting lever; 67. Limiting spring; 68. Top plate; 69. Limiting component mounting hole; 7. Rotor; 71. Permanent magnet layer; 72. Spacer plate; 73. Rectangular hole; 8. Drive shaft; 81. Round hole; 82. Shaft body; 83. Limiting component; 9. Stator. Detailed Implementation

[0017] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please refer to Figures 1-8 The present invention will now describe a high-torque, low-speed submersible permanent magnet motor, as follows: Figures 1-2The motor housing includes a tailstock cap 1, a motor base 2, a motor housing 3, a motor head 4, a transport cap 5, a centering bearing 6, a rotor 7, a drive shaft 8, and a stator 9. The motor housing 3 is connected to the motor head 4 and the motor base 2 at both ends. The transport cap 5 and the tailstock cap 1 are installed on the outer ends of the motor head 4 and the motor base 2, respectively. The stator 9 is installed in the motor housing 3. The drive shaft 8 is installed in the motor housing 3. The two ends of the drive shaft 8 are inserted into the motor head 4 and the motor base 2. The drive shaft 8 is located inside the stator 9. Several rotors 7 are installed on the outer side of the drive shaft 8. Several centering bearings 6 are also installed on the outer side of the drive shaft 8. The centering bearings 6 are located between two rotors 7 or on the outer side of the rotors 7. The centering bearings 6 and the rotors 7 are located inside the stator 9. The tail cap 1 is designed to work with the motor base 2 to form an oil storage space, making it easier to lift the liquid after it enters. The transport cap 5 effectively prevents oil leakage from the top. The centering bearing 6 increases the radial load capacity through its self-lubricating ability. The multi-rotor design 7, compared to the existing single rotor 7, can significantly increase the air gap magnetic field density, thereby increasing the torque. This avoids the problem of small-diameter reducers with small diameters and low torque in small-diameter wellbores, which cannot adapt to various operating environments.

[0019] In a specific embodiment, such as Figure 3 The motor base 2 includes a connector 21, a first connecting seat 22, an oil inlet channel 23, a second limiting ring 24, a first limiting ring 25, and a first thread 26. The connector 21 has a connecting hole inside, and the bottom end of the drive shaft 8 is set in the connecting hole. The bottom of the connector 21 has an insertion hole that communicates with the connecting hole. The tail cap 1 is inserted into the insertion hole. The first connecting seat 22 is set on the side wall of the connector 21. A one-way valve is installed in the first connecting seat 22. The connector 21 also has an oil inlet channel 23. The top end of the oil inlet channel 23 communicates with the inside of the motor housing 3. The first thread 26 is set on the outside of the connector 21 and is located above the first connecting seat 22. The first limiting ring 25 is installed in the connector 21. The second limiting ring 24 is installed inside the first limiting ring 25 and is sleeved on the outside of the bottom end of the drive shaft 8. After the oil enters the motor base 2 through the one-way valve, it is not directly drawn upwards. Instead, it first enters the oil storage space formed by the motor base 2 and the tail cap 1, and then is drawn upwards through the oil inlet channel 23. This allows large particles of impurities in the oil to remain at the upper end of the tail cap 1 and not be directly drawn out, thus reducing the need for filtration. The first connecting seat 22 is used to install the one-way valve. The second limiting ring 24 and the first limiting ring 25 are used to block the channel between the connecting hole and the motor housing 3 to prevent the oil from directly entering the motor housing 3 from the channel. The first thread 26 is used to connect the motor base 2 and the motor housing 3 together.

[0020] In a specific embodiment, such as Figure 4 The motor head 4 includes a limiting member 41, a second thread 42, a second connecting seat 43, a thrust bearing 44, a mounting member 45, a mounting hole 46, and a lead wire cover 47. The mounting member 45 has a mounting hole 46 inside, the upper end of the drive shaft 8 is set in the mounting hole 46, and the top end of the drive shaft 8 is set in the transport cap 5. The mounting member 45 has a second thread 42 on its outer side. The second connecting seat 43 is opened on the side wall of the mounting member 45, and a one-way valve is installed in the second connecting seat 43. There are two limiting members 41, which are installed in the mounting hole 46. The thrust bearing 44 is also installed in the mounting hole 46 and is sleeved on the outer side of the drive shaft 8. The lead wire hole is opened on the side of the mounting member 45, and a lead wire cover 47 is inserted into the end of the lead wire hole. The limiting component 41 is designed to ensure that the rotation of the drive shaft 8 will not deviate, and also to prevent oil from passing through and ensure that the oil is discharged through the designated outlet. The second thread 42 is used to connect the motor head 4 and the motor housing 3. The thrust bearing 44 is designed to increase the suspension weight of the entire motor and limit the downward movement of the drive shaft 8. The lead wire hole is designed to allow the wire to pass through so that the stator 9 can be connected to the power supply. The lead wire cover 47 is used to protect the wire and also to prevent dust from entering.

[0021] In a specific embodiment, such as Figure 5 The drive shaft 8 includes a circular hole 81, a shaft body 82, and a limiting member 83. The circular hole 81 is located in the middle of the shaft body 82. The limiting members 83 are arranged in pairs and installed on the outside of the shaft body 82, abutting against the outside of the centering bearing 6. The circular hole 81 is designed to make the drive shaft 8 a hollow shaft. In addition to reducing weight, a hollow shaft can also have higher torsional stiffness. The limiting member 83 is used to limit the position of the rotor 7.

[0022] In a specific embodiment, such as Figures 6-7The centering bearing 6 includes a bearing housing 61, an annular limiting plate 62, a bearing sleeve 63, an oil passage hole 64, an L-shaped limiting plate 66, a limiting spring 67, a top plate 68, and a limiting component mounting hole 69. The bearing housing 61 has an annular structure, and the bearing sleeve 63 is rotatably connected to the inner surface of the bearing housing 61. The bearing sleeve 63 is sleeved on the outside of the transmission shaft 8. Several oil passage holes 64 are opened on the bearing housing 61. The annular limiting plate 62 is installed on the outside of the bearing housing 61. The limiting component mounting hole 69 is opened on the annular limiting plate 62 and extends into the bearing housing 61. One end of the limiting spring 67 is installed in the limiting component mounting hole 69, and the other end of the limiting spring 67 is installed with an L-shaped limiting plate 66. The outer end of the L-shaped limiting plate 66 abuts against the inner wall of the annular limiting plate 62. The top plate 68 is installed on the outside of the L-shaped limiting plate 66. The bearing sleeve 63 is installed on the outside of the drive shaft 8. The centering bearing 6 itself is a sliding bearing. The rotation of the drive shaft 8 is achieved by the sliding of the bearing sleeve 63 in the bearing housing 61. The oil passage hole 64 allows oil to pass through. The oil passage hole 64 can communicate with the limiting component mounting hole 69. In this way, the oil can enter the contact position between the top plate 68 and the stator 9, and also the contact position between the bearing sleeve 63 and the bearing housing 61 for lubrication. This setting can reduce the radial force during rotation, thereby increasing the radial load. The limiting spring 67 uses its elastic force to press the centering bearing 6 against the inner wall of the stator 9 to limit the position of the centering bearing 6 on the drive shaft 8. Since the limiting spring 67 is always in a compressed state, an L-shaped limiting tab 66 is needed to prevent the top plate 68 from slipping off.

[0023] In a specific embodiment, such as Figure 8 A permanent magnet layer 71 is attached to the outer surface of the rotor 7. A spacer plate 72 is connected to the end of the rotor 7. A slot is provided in the rotor 7, and a rectangular hole 73 is opened on the side wall of the slot. The permanent magnet layer 71 adopts a ring-shaped Hellbeck magnet structure. The spacer plate 72 is set to separate the rotor 7 from the centering bearing 6 to prevent mutual wear. The rectangular hole 73 is used to drive the rotor 7 to rotate.

[0024] In one specific embodiment, the stator 9 is constructed using stator laminations with a closed-slot structure. The stator 9 is connected to stator end plates and insulating end plates. The stator structure is made of 0.5mm thick non-oriented electrical steel laminated together. The stator winding uses high-temperature resistant polyimide film sintered wire, and the stator winding adopts a fractional-slot concentrated winding configuration, which is beneficial to improving the power density of the motor. The stator end plates and insulating end plates ensure the insulation performance and mechanical stability of the stator core.

[0025] In a specific embodiment, such as Figure 4The transport cap 5 is equipped with a positioning shaft 52 and a spline sleeve 51. One end of the spline sleeve 51 is fitted onto the outside of the drive shaft 8, and the positioning shaft 52 is inserted into the other end of the spline sleeve 51. The positioning shaft 52 is used to determine the installation position and to prevent the drive shaft 8 from shifting during rotation.

[0026] In use, the entire motor is inserted into the wellbore. The stator 9 is equipped with three-phase cables that are connected to an external power source. The power source supplies power to the stator 9, generating a magnetic field. Similar to a conventional three-phase asynchronous motor, the stator 9 generates a rotating magnetic field under the action of alternating current. This magnetic field in turn generates magnetic force. The rotor 7 has permanent magnets attached to its outer side. Under the action of magnetic force, the rotating magnetic field attracts the rotor 7 to rotate. During the rotation, the oil is pushed upward, completing the oil extraction process.

[0027] During the oil extraction process, oil is drawn into the connection hole from the one-way valve in the motor base 2. The force of suction is transmitted to the connection hole through the sealing of the second limit ring 24 and the first limit ring 25. At this time, under the influence of gravity, the oil falls into the insertion hole, and the tail cap 1 seals the insertion hole, forming an oil storage space between the insertion hole and the tail cap 1. The oil in the oil storage space is drawn out from the oil inlet channel 23 under the action of the lifting force and enters the motor housing 3. The oil continues to rise and flows through the gap between the rotor 7 and the stator 9 under the action of the lifting force. When it flows through the centering bearing 6, it lubricates the centering bearing 6. Finally, the oil is sent to the one-way valve in the motor head 4. The extracted oil is discharged through the one-way valve connecting pipe.

[0028] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A large-torque low-speed submersible permanent magnet motor, characterized in that, include: The motor housing (3) has a motor head (4) and a motor base (2) connected to its two ends respectively. The outer ends of the motor head (4) and the motor base (2) are respectively equipped with a transport cap (5) and a tail cap (1). The stator (9) is installed in the motor housing (3); A drive shaft (8) is installed in the motor housing (3). Both ends of the drive shaft (8) are inserted into the motor head (4) and the motor base (2). The drive shaft (8) is located inside the stator (9). Several rotors (7) are installed on the outside of the drive shaft (8). Several straightening bearings (6) are also installed on the outside of the drive shaft (8). The straightening bearings (6) are located between two rotors (7) or on the outside of the rotors (7). The straightening bearings (6) and the rotors (7) are located on the inside of the stator (9).

2. The large-torque low-speed submersible permanent-magnet motor of claim 1, wherein, The motor base (2) includes: The connector (21) has a connecting hole inside. The bottom end of the drive shaft (8) is set in the connecting hole. The bottom of the connector (21) has an insertion hole. The insertion hole is connected to the connecting hole. The tail cap (1) is inserted into the insertion hole. The first connecting seat (22) is opened on the side wall of the connecting member (21). A one-way valve is installed in the first connecting seat (22). An oil inlet channel (23) is also opened in the connecting member (21). The top of the oil inlet channel (23) is connected to the inside of the motor housing (3). A first thread (26) is formed on the outside of the connector (21), and the first thread (26) is disposed above the first connector (22); A first limiting ring (25) is installed in the connector (21), and a second limiting ring (24) is installed inside the first limiting ring (25). The second limiting ring (24) is sleeved on the outside of the bottom end of the transmission shaft (8).

3. The high-torque, low-speed submersible permanent magnet motor as described in claim 1, characterized in that, The motor head (4) includes: The mounting part (45) has a mounting hole (46) inside. The upper end of the drive shaft (8) is disposed in the mounting hole (46), and the top end of the drive shaft (8) is disposed in the transport cap (5). The mounting part (45) has a second thread (42) on the outside. A second connecting seat (43) is provided on the side wall of the mounting component (45), and a one-way valve is installed in the second connecting seat (43); Two limiting members (41) are provided and installed in the mounting hole (46). A thrust bearing (44) is also installed in the mounting hole (46). The thrust bearing (44) is sleeved on the outside of the transmission shaft (8). A lead hole is provided on the side of the mounting (45), and a lead cover (47) is inserted at the end of the lead hole.

4. The high-torque, low-speed submersible permanent magnet motor as described in claim 1, characterized in that, The drive shaft (8) includes: The shaft (82) has a round hole (81) in the middle. A pair of limiting members (83) are installed on the outside of the shaft (82), and the limiting members (83) abut against the outside of the straightening bearing (6).

5. The high-torque, low-speed submersible permanent magnet motor as described in claim 1, characterized in that, The centering bearing (6) includes: The bearing housing (61) has a ring structure. A bearing sleeve (63) is rotatably connected to the inner surface of the bearing housing (61). The bearing sleeve (63) is sleeved on the outside of the transmission shaft (8). Several oil passage holes (64) are provided on the bearing housing (61), and an annular limiting plate (62) is installed on the outside of the bearing housing (61). A mounting hole (69) for limiting the component is formed on the annular limiting plate (62) and extends into the bearing seat (61); A limiting spring (67) is installed at one end in the mounting hole (69) of the limiting component, and an L-shaped limiting lever (66) is installed at the other end of the limiting spring (67). The outer end of the L-shaped limiting lever (66) abuts against the inner wall of the annular limiting plate (62). The top plate (68) is installed on the outside of the L-shaped limiting paddle (66).

6. The high-torque, low-speed submersible permanent magnet motor as described in claim 1, characterized in that, A permanent magnet layer (71) is attached to the outer surface of the rotor (7), a spacer plate (72) is connected to the end of the rotor (7), a slot is provided in the rotor (7), and a rectangular hole (73) is opened on the side wall of the slot.

7. The high-torque, low-speed submersible permanent magnet motor as described in claim 1, characterized in that, The stator (9) is made of stator laminations, the stator laminations adopt a closed slot structure, and the stator (9) is connected to a stator end plate and an insulating end plate.

8. The high-torque, low-speed submersible permanent magnet motor as described in claim 1, characterized in that, The transport cap (5) is provided with a positioning shaft (52) and a spline sleeve (51). One end of the spline sleeve (51) is sleeved on the outside of the transmission shaft (8), and the positioning shaft (52) is inserted into the other end of the spline sleeve (51).

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