A new process for press-fitting a downhole submersible permanent magnet motor

Abstract

The application relates to a new process for press assembling a downhole oil-submersible permanent magnet motor. The technical scheme comprises the following steps: 1, core shaft passes through silicon steel laminations: a positioning key is pasted on the core shaft, the motor silicon steel laminations pass through the core shaft, and a compression pipe, a compression pipe baffle and a hexagonal nut are sequentially installed at both ends of the core shaft; 2, silicon steel lamination pre-compression; 3, installation of a fixing key on the silicon steel lamination: the fixing key is knocked into a key groove on the outer circle of the silicon steel lamination; 4, silicon steel lamination compression into a motor shell: the silicon steel laminations pass into the motor shell, a lower end positioning inner clamping spring is installed on the shell, the silicon steel laminations are compressed to expose an upper end inner clamping spring groove through a horizontal press, then the positioning inner clamping spring is installed into the motor shell, and the core shaft is pressed out of the silicon steel laminations; 5, welding of the fixing key. The application solves the problem of large starting torque of a downhole permanent magnet synchronous motor, the silicon steel laminations of the motor are prone to moving and damaging the coil, and the service life of the downhole permanent magnet synchronous motor is prolonged.

Description

Technical Field

[0001] This invention relates to an assembly technology for a downhole submersible permanent magnet motor, and particularly to a new press-fitting process for a downhole submersible permanent magnet motor. Background Technology

[0002] In the petroleum industry, downhole submersible permanent magnet motors (PMMA) are commonly used motors for submersible pumps. Installed inside the casing downhole, these motors require a slender structure and high starting torque. Conventional stator press-fitting processes for downhole PMA cannot meet the high torque requirements during startup, easily causing the stator silicon steel laminations to rotate. While surface PMA can utilize its housing structure to prevent the stator silicon steel laminations from rotating during high-torque startup, downhole PMA synchronous motors, constrained by casing dimensions, must be made extremely thin and long. Therefore, the motor housing cannot be specially structured to limit potential rotational displacement of the stator silicon steel laminations. Consequently, the assembly process must be optimized to control the rotational displacement of the stator silicon steel laminations during startup. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned deficiencies in existing technologies by providing a new press-fitting process for downhole submersible permanent magnet motors, effectively solving the problem of stator silicon steel lamination rotation and displacement that may be caused by the large starting torque of downhole permanent magnet motors.

[0004] The present invention discloses a novel press-fitting process for a downhole submersible permanent magnet motor, the technical solution of which includes the following steps:

[0005] 1. Mandrel with silicon steel laminations: A positioning key (2) is pasted on the mandrel (1). One or more sets of motor silicon steel laminations (3) are passed through the mandrel (1). A clamping tube (4), a clamping tube baffle (5) and a hexagonal nut (6) are installed at both ends of the mandrel (1) in sequence.

[0006] 2. Pre-pressing of silicon steel laminations: Place the assembled device on the frame of the horizontal press. Install the tightening nuts and pressure heads (7) at both ends of the mandrel (1) and the pressing baffle (8) at the rear end of the mandrel (1). Press the device with the pressure head of the horizontal press. After the pressure value and the length of the silicon steel laminations (3) meet the technical requirements, tighten the hexagonal nuts (6) at both ends with a wrench, release the pressure, and remove the pressing baffle (8) and the tightening nuts and pressure heads (7) at both ends.

[0007] 3. Install the fixing key on the silicon steel lamination: Cut a fixing key (9) of appropriate length and use a rubber mallet to knock the fixing key (9) into the keyway on the outer circle of the silicon steel lamination (3);

[0008] 4. Pressing silicon steel laminations into the motor housing: The silicon steel laminations (3) are inserted into the motor housing (10). The lower end of the housing is positioned by the inner retaining ring (11), so that the lower end of the silicon steel laminations (3) rests on the inner retaining ring (11). The upper end is fitted with a tightening nut press head (7). The silicon steel laminations (3) are compressed by a horizontal press and exposed in the upper inner retaining ring groove. Then, the inner retaining ring (11) is installed into the motor housing (10). The hexagonal nut (6) at the front end is unscrewed, the horizontal press is depressurized, and the press baffle (8), tightening nut press head (7), pressing tube baffle (5), and pressing tube (4) are removed. The mandrel (1) is pressed out from the silicon steel laminations (3).

[0009] 5. Welding the fixing key: Drill several holes at appropriate positions on the motor housing (10), up to the position of the fixing key (9), and weld the fixing key (9) to the motor housing (10) using carbon dioxide shielded welding and fill the drill holes with welding repair (12); after welding, conduct a sealing test to ensure the weld is sealed and complete the press-fitting of the downhole submersible permanent magnet motor.

[0010] Preferably, the aforementioned mandrel (1) includes a mandrel body (1.1) and a connecting shaft (1.2), with connecting shafts (1.2) provided at both ends of the mandrel body (1.1), and the outer diameter of the connecting shaft (1.2) being smaller than the outer diameter of the mandrel body (1.1).

[0011] Preferably, the outer side of the aforementioned mandrel body (1.1) is provided with a positioning groove (1.3) for installing and fixing the positioning key (2).

[0012] Preferably, the above-mentioned clamping tube (4) includes a clamping tube body (4.1), a male head (4.2), and a female head (4.3). One end of the clamping tube body (4.1) is provided with a male head (4.2) for contacting the silicon steel lamination (3), and the other end is provided with a female head (4.3) for contacting the clamping tube baffle (5).

[0013] Preferably, the above-mentioned clamping tube baffle (5) includes a clamping tube baffle body (5.1), a left baffle (5.2), and a right baffle (5.3). The clamping tube baffle body (5.1) is a cylindrical structure, and its inner cavity is fitted on the outer wall of the connecting shaft (1.2). The left baffle (5.2) is provided on the left side of the clamping tube baffle body (5.1), and the right baffle (5.3) is provided on the right side. The outer diameter of the left baffle (5.2) is smaller than the inner diameter of the female head (4.3) of the clamping tube (4). The right baffle (5.3) is connected and cooperates with the tightening nut head (7).

[0014] Preferably, the silicon steel lamination (3) is fixed to the motor housing (10) by a fixing key (9), and a positioning inner retaining spring (11) is installed inside the motor housing (10), with the end of the silicon steel lamination (3) pressing against the positioning inner retaining spring (11).

[0015] Preferably, the aforementioned positioning inner retaining ring (11) is a ring with a notch.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention, by passing the mandrel through silicon steel laminations, pre-pressing the silicon steel laminations, installing fixing keys on the laminations, pressing the silicon steel laminations into the housing, and finally welding the fixing keys, avoids the rotational displacement of the stator silicon steel laminations and is also suitable for thin and long oil casings; therefore, the present invention solves the problem of high starting torque of downhole permanent magnet synchronous motors and the easy movement of stator silicon steel laminations that damages the coils, thus improving the service life of downhole permanent magnet synchronous motors. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the installation structure after the mandrel passes through the silicon steel laminations;

[0018] Figure 2 This is a schematic diagram of the pre-compression structure of the silicon steel laminations of the present invention;

[0019] Figure 3 This is a schematic diagram of the structure of the present invention, which involves installing a fixing key on a silicon steel lamination.

[0020] Figure 4 This is a schematic diagram of the structure of the silicon steel laminations of the present invention after being pressed into the motor housing;

[0021] Figure 5 This is a schematic diagram of the structure of the present invention after the mandrel is removed and the fixing key is welded.

[0022] Figure 6 This is a schematic diagram of the mandrel structure of the present invention;

[0023] Figure 7 This is a cross-sectional schematic diagram of the mandrel of the present invention.

[0024] Figure 8 This is a schematic diagram of the structure of the compression tube of the present invention;

[0025] Figure 9 This is a schematic diagram of the structure of the clamping tube baffle of the present invention;

[0026] Figure 10 This is a schematic diagram of the positioning inner retaining spring of the present invention;

[0027] In the above diagram: 1. Mandrel; 2. Positioning key; 3. Motor silicon steel laminations; 4. Clamping tube; 5. Clamping tube baffle; 6. Hexagonal nut; 7. Tightening nut head; 8. Pressing baffle; 9. Fixing key; 10. Motor housing; 11. Positioning inner snap ring; 12. Drilling and welding repair; 1.1. Mandrel body; 1.2. Connecting shaft; 1.3. Positioning groove; 4.1. Clamping tube body; 4.2. Male head; 4.3. Female head; 5.1. Clamping tube baffle body; 5.2. Left baffle; 5.3. Detailed Implementation

[0028] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0029] Example 1, referring to Figures 1-5 The present invention discloses a novel press-fitting process for a downhole submersible permanent magnet motor, comprising the following steps:

[0030] 1. Mandrel with silicon steel laminations: A positioning key 2 is attached to the mandrel 1. One or more sets of silicon steel laminations 3 of the motor are passed through the mandrel 1. A clamping tube 4, a clamping tube baffle 5 and a hexagonal nut 6 are installed at both ends of the mandrel 1 in sequence.

[0031] 2. Pre-pressing of silicon steel laminations: Place the assembled device on the frame of the horizontal press. Install the tightening nuts 7 at both ends of the mandrel 1 and the pressing baffle 8 at the rear end of the mandrel 1. Press the device with the press head of the horizontal press. After the pressure value and the length of the silicon steel laminations 3 meet the technical requirements, tighten the hexagonal nuts 6 at both ends with a wrench, release the pressure, and remove the pressing baffle 8 and the tightening nuts 7 at both ends.

[0032] 3. Install the fixing key on the silicon steel lamination: Cut a fixing key 9 of appropriate length and use a rubber mallet to tap the fixing key 9 into the keyway on the outer circle of the silicon steel lamination 3;

[0033] IV. Pressing the silicon steel laminations into the motor housing: The silicon steel laminations 3 are inserted into the motor housing 10. The lower end of the housing is positioned by the inner retaining spring 11, so that the lower end of the silicon steel laminations 3 rests on the inner retaining spring 11. The upper end is fitted with a tightening nut pressure head 7. The silicon steel laminations 3 are compressed by a horizontal press and exposed in the upper inner retaining spring groove. Then, the inner retaining spring 11 is installed into the motor housing 10. The hexagonal nut 6 at the front end is unscrewed, the horizontal press is depressurized, and the pressing baffle 8, the tightening nut pressure head 7, the pressing tube baffle 5, and the pressing tube 4 are removed. The mandrel 1 is then pressed out from inside the silicon steel laminations 3.

[0034] 5. Welding the fixing key: Drill several holes at appropriate positions on the motor housing 10, up to the position of the fixing key 9. Weld the fixing key 9 to the motor housing 10 using carbon dioxide shielded welding and fill the drilled holes with weld repair 12. After welding, conduct a sealing test to ensure the weld is sealed and complete the press-fitting of the downhole submersible permanent magnet motor.

[0035] The aforementioned mandrel 1 includes a mandrel body 1.1 and a connecting shaft 1.2. The connecting shaft 1.2 is provided at both ends of the mandrel body 1.1, and the outer diameter of the connecting shaft 1.2 is smaller than the outer diameter of the mandrel body 1.1.

[0036] Reference Figure 6 The outer side of the mandrel body 1.1 of the present invention is provided with a positioning groove 1.3 for installing and fixing the positioning key 2.

[0037] Reference Figure 7 The clamping tube 4 of the present invention includes a clamping tube body 4.1, a male head 4.2, and a female head 4.3. One end of the clamping tube body 4.1 is provided with a male head 4.2 for contacting the silicon steel lamination 3, and the other end is provided with a female head 4.3 for contacting the clamping tube baffle 5.

[0038] Reference Figure 8 The clamping tube baffle 5 of the present invention includes a clamping tube baffle body 5.1, a left baffle 5.2, and a right baffle 5.3. The clamping tube baffle body 5.1 has a cylindrical structure, and its inner cavity is fitted on the outer wall of the connecting shaft 1.2. The left baffle 5.2 is provided on the left side of the clamping tube baffle body 5.1, and the right baffle 5.3 is provided on the right side. The outer diameter of the left baffle 5.2 is smaller than the inner diameter of the female head 4.3 of the clamping tube 4. The right baffle 5.3 is connected and cooperates with the tightening nut head 7.

[0039] Reference Figure 9 The silicon steel laminate 3 of the present invention is fixed to the motor housing 10 by a fixing key 9, and a positioning inner retaining spring 11 is installed inside the motor housing 10, with the end of the silicon steel laminate 3 pressing against the positioning inner retaining spring 11.

[0040] Reference Figure 10 The aforementioned positioning inner retaining ring 11 is a notched circular ring, which facilitates installation and serves a positioning function.

[0041] This invention prevents the stator silicon steel laminations from rotating and shifting by inserting a mandrel through silicon steel laminations, pre-pressing the silicon steel laminations, installing fixing keys on the laminations, pressing the silicon steel laminations into the housing, and finally welding the fixing keys. This also makes it suitable for thin and long oil casings. Therefore, this invention solves the problem of high starting torque in downhole permanent magnet synchronous motors, which easily leads to the movement of stator silicon steel laminations and damage to the coils, and improves the service life of downhole permanent magnet synchronous motors.

[0042] Example 2: A novel press-fitting process for a downhole submersible permanent magnet motor mentioned in this invention includes the following steps:

[0043] 1. Inserting Silicon Steel Laminates onto the Mandrel: First, attach the positioning key 2, which matches the silicon steel laminate 3, to the mandrel 1. After the adhesive has cured, insert the motor silicon steel laminate 3 into the mandrel 1 according to the required quantity for different products, and manually press it firmly, making it slightly longer than the length pressed by a press. Then, symmetrically install the clamping tube 4, clamping tube baffle 5, and hexagonal nut 6 at both ends of the mandrel 1.

[0044] 2. Pre-pressing of silicon steel laminations: The whole assembly is placed on the horizontal press frame. The mandrel 1 is fitted with the tightening nuts 7 at both ends. The press baffle 8 is installed at the rear end of the mandrel 1. The press head of the horizontal press applies pressure. After the pressure value and the length of the silicon steel laminations 3 meet the technical requirements, the hexagonal nuts 6 at both ends are tightened with a wrench. The pressure is released, and the press baffle 8 and the tightening nuts 7 at both ends are removed.

[0045] 3. Install the fixing key on the silicon steel lamination: Cut a fixing key 9 of appropriate length and use a rubber mallet to tap the fixing key into the keyway on the outer circle of the silicon steel lamination 3.

[0046] IV. Pressing the silicon steel laminations into the motor housing: The silicon steel laminations 3 are inserted into the motor housing 10. The lower end of the housing is positioned by the inner retaining spring 11, so that the lower end of the silicon steel laminations 3 rests on the inner retaining spring 11. The upper end is fitted with the tightening nut pressure head 7. The press applies pressure to compress the silicon steel laminations 3, exposing the upper inner retaining spring groove. The other inner retaining spring 11 is then installed into the motor housing 10 using a special tool. The hexagonal nut 6 at the front end is unscrewed, the press is depressurized, and the press baffle 8, tightening nut pressure head 7, pressing tube baffle 5, and pressing tube 4 are removed in sequence to press the mandrel 1 out from inside the silicon steel laminations 3.

[0047] 5. Welding the fixing key: Drill several holes at appropriate positions on the motor housing 10, up to the position of the fixing key 9. Weld the fixing key 9 to the motor housing 10 using carbon dioxide shielded welding and fill the drilled holes with weld repair 12. After welding, conduct a sealing test to ensure the weld is sealed and complete the press-fitting of the downhole submersible permanent magnet motor.

[0048] The above description is merely a partial preferred embodiment of the present invention. Any person skilled in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, any simple modifications or equivalent transformations made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A novel press-fitting process for a downhole submersible permanent magnet motor, characterized by: Includes the following steps:

1. Mandrel with silicon steel laminations: A positioning key (2) is pasted on the mandrel (1). One or more sets of motor silicon steel laminations (3) are passed through the mandrel (1). A clamping tube (4), a clamping tube baffle (5) and a hexagonal nut (6) are installed at both ends of the mandrel (1) in sequence.

2. Pre-pressing of silicon steel laminations: Place the assembled device on the frame of the horizontal press. Install the tightening nuts and pressure heads (7) at both ends of the mandrel (1) and the pressing baffle (8) at the rear end of the mandrel (1). Press the device with the pressure head of the horizontal press. After the pressure value and the length of the silicon steel laminations (3) meet the technical requirements, tighten the hexagonal nuts (6) at both ends with a wrench, release the pressure, and remove the pressing baffle (8) and the tightening nuts and pressure heads (7) at both ends.

3. Install the fixing key on the silicon steel lamination: Cut a fixing key (9) of appropriate length and use a rubber mallet to knock the fixing key (9) into the keyway on the outer circle of the silicon steel lamination (3); 4. Pressing silicon steel laminations into the motor housing: The silicon steel laminations (3) are inserted into the motor housing (10). The lower end of the housing is positioned by the inner retaining ring (11), so that the lower end of the silicon steel laminations (3) rests on the inner retaining ring (11). The upper end is fitted with a tightening nut press head (7). The silicon steel laminations (3) are compressed by a horizontal press and exposed in the upper inner retaining ring groove. Then, the inner retaining ring (11) is installed into the motor housing (10). The hexagonal nut (6) at the front end is unscrewed, the horizontal press is depressurized, and the press baffle (8), tightening nut press head (7), pressing tube baffle (5), and pressing tube (4) are removed. The mandrel (1) is pressed out from the silicon steel laminations (3).

5. Welding the fixing key: Drill several holes at appropriate positions on the motor housing (10), up to the position of the fixing key (9), and weld the fixing key (9) to the motor housing (10) using carbon dioxide shielded welding and fill the drill holes with welding repair (12); after welding, conduct a sealing test to ensure the weld is sealed and complete the press-fitting of the downhole submersible permanent magnet motor.

2. The new press-fitting process for downhole submersible permanent magnet motors according to claim 1, characterized in that: The mandrel (1) includes a mandrel body (1.1) and a connecting shaft (1.2). The connecting shaft (1.2) is provided at both ends of the mandrel body (1.1), and the outer diameter of the connecting shaft (1.2) is smaller than the outer diameter of the mandrel body (1.1).

3. The new press-fitting process for downhole submersible permanent magnet motors according to claim 2, characterized in that: The outer side of the spindle body (1.1) is provided with a positioning groove (1.3) for installing and fixing the positioning key (2).

4. The new press-fitting process for downhole submersible permanent magnet motors according to claim 3, characterized in that: The clamping tube (4) includes a clamping tube body (4.1), a male head (4.2), and a female head (4.3). One end of the clamping tube body (4.1) is provided with a male head (4.2) for contacting the silicon steel lamination (3), and the other end is provided with a female head (4.3) for contacting the clamping tube baffle (5).

5. The new press-fitting process for downhole submersible permanent magnet motors according to claim 4, characterized in that: The clamping tube baffle (5) includes a clamping tube baffle body (5.1), a left baffle (5.2), and a right baffle (5.3). The clamping tube baffle body (5.1) is a cylindrical structure with its inner cavity fitted onto the outer wall of the connecting shaft (1.2). The left baffle (5.2) is provided on the left side of the clamping tube baffle body (5.1), and the right baffle (5.3) is provided on the right side. The outer diameter of the left baffle (5.2) is smaller than the inner diameter of the female head (4.3) of the clamping tube (4). The right baffle (5.3) is connected and cooperates with the tightening nut head (7).

6. The new press-fitting process for downhole submersible permanent magnet motors according to claim 5, characterized in that: The silicon steel lamination (3) is fixed to the motor housing (10) by a fixing key (9), and a positioning inner retaining spring (11) is installed inside the motor housing (10), with the end of the silicon steel lamination (3) pressing against the positioning inner retaining spring (11).

7. The new press-fitting process for downhole submersible permanent magnet motors according to claim 5, characterized in that: The positioning inner retaining ring (11) is a ring with a notch.

Images