Direct-current servo drive motor for oil pumping unit

Abstract

The utility model discloses a direct-current servo drive motor for an oil pumping unit, which comprises a casing and a central shaft, and the central shaft and the casing are coaxially arranged. The stator and rotor module is used for driving the center shaft to rotate, the installation module is used for installing and positioning the stator and rotor module, the shaft end module is used for forming a motor shaft end function part, the stator and rotor module is arranged in the middle of the inner side of the machine shell, and the installation module is assembled at the end of the machine shell. The beneficial effects of the utility model are that the stator and rotor modules are arranged, on the premise that the use technical indexes are not changed by changing the stator and rotor sheet types, the material of the originally designed motor is reduced, the manufacturing cost is reduced, the control mode of switched reluctance modeling is adopted, and the reliability of the motor is improved. The control precision and low-speed torque optimization are comprehensively improved, meanwhile, the low-speed pulsation is reduced, and the reliability of a traction system is improved when the oil pumping unit operates under the long-time low-speed heavy-load working condition.

Description

Technical Field

[0001] The utility model relates to the technical field of driving motors for pumping units, in particular to a DC servo driving motor for a pumping unit. Background Art

[0002] In the prior art, pumping units such as beam pumping units, high plateau pumping units, and tower pumping units have rotating driving links such as electric motors, belts, gearboxes, and guide wheels. The electric motors are usually three-phase asynchronous motors, permanent magnet synchronous motors, variable frequency motors, switched reluctance motors, etc. Although the rated efficiency can reach over 92%, due to the extremely unbalanced load torque within each stroke of the pumping unit, especially under working conditions such as low strokes and light loads, when the motor speed is lower than 50% of the rated speed or even lower, the efficiency and power factor of induction motors, variable frequency motors, and permanent magnet synchronous motors under light loads are very low. Therefore, the comprehensive efficiency is not high, and the belt is very easy to wear. As the degree of wear increases, the efficiency will also decrease. It can only meet the on-site use by replacing the belt pulley and the low-speed motor, resulting in high labor costs and spare parts costs. When hanging operations need to be carried out by the motor on-site, the motor needs to provide sufficient starting torque and low-speed torque output characteristics, which is also a very challenging performance index for the motor. At present, there are still technical problems such as insufficient torque index during low-speed heavy-load operation of the pumping unit and current impact on the motor and controller under sudden heavy-load conditions during low-speed operation, which are likely to cause equipment damage.

[0003] Chinese Utility Model Patent with Application No. 201720868389.0 discloses an in-built permanent magnet synchronous motor for a tower pumping unit, which relates to the technical field of driving motors for tower pumping units and solves technical problems such as the over-large volume of the driving system of the tower pumping unit, much occupied space, low system efficiency, and high failure rate. The in-built permanent magnet synchronous motor for the tower pumping unit includes a stator and a rotor. The stator includes a winding stator core and a machine shell. The rotor includes a rotor core, a rotating shaft, and permanent magnets. The motor rotating shaft is located inside the machine shell. End covers are installed at both ends of the machine shell. A brake is connected to the non-shaft extension end of the motor, and a reduction mechanism is connected to the output end of the rotating shaft. The reduction mechanism includes a sun gear, a reduction transmission device, and a reduction output shaft. A spline is machined at the output end of the motor rotating shaft, and an internal spline adapted to the spline is machined on the sun gear. However, this in-built permanent magnet synchronous motor for the tower pumping unit has poor reliability during long-term low-speed heavy-load operation, and mechanical vibration noise is easily caused due to motor pulsation. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a DC servo driving motor for a pumping unit.

[0005] To achieve the above purpose, the technical solution proposed by the utility model is:

[0006] A DC servo drive motor for a pumping unit, comprising a housing and a central shaft. The central shaft is coaxially arranged with the housing. It further includes a stator-rotor module for driving the central shaft to rotate, a mounting module for mounting and positioning the stator-rotor module, and a shaft end module for constituting the functional part of the motor shaft end. The stator-rotor module is arranged in the middle inside of the housing, the mounting module is assembled at the end of the housing, and the shaft end module is configured at one end of the central shaft.

[0007] The stator-rotor module includes a rotor sheet, a stator sheet, and a coil. The rotor sheet is sleeved on the outer side of the middle part of the central shaft and is key-connected to the central shaft. The stator sheet is arranged on the outer side of the rotor sheet and is sleeved with the rotor sheet. The coil is arranged on the side part of the stator sheet and is wound and connected with the stator sheet.

[0008] A number of groups of salient pole structures are evenly arranged on the outer peripheral part of the rotor sheet. The root part of the salient pole of the rotor sheet is set as an arc-shaped rounded corner structure, and salient pole groove structures are symmetrically arranged on both sides of the end part of the salient pole of the rotor sheet.

[0009] A number of groups of recessed pole structures are evenly arranged on the inner side of the stator sheet. A right-angle groove structure is arranged between the several groups of recessed poles of the stator sheet, and recessed pole groove structures are symmetrically arranged on both sides of the end part of the recessed pole of the stator sheet.

[0010] It further includes mounting grooves. There are several groups of mounting grooves, and the several groups of mounting grooves are evenly arranged around the outer peripheral part of the stator sheet.

[0011] The mounting module includes an inner gland and an end cover. There are two groups of inner glands, and the two groups of inner glands are symmetrically arranged at both ends of the central shaft and are sleeved with the central shaft. The two groups of inner glands are located on both sides of the stator-rotor module. There are two groups of end covers, and the two groups of end covers are symmetrically arranged at both ends of the housing and are fixedly connected with the housing. The two groups of end covers are respectively located outside the two groups of inner glands.

[0012] It further includes bearings and outer glands. There are two groups of bearings, and the two groups of bearings are respectively arranged outside the two groups of inner glands and are sleeved with the central shaft. The bearings are located inside the corresponding end covers. There are two groups of outer glands, and the two groups of outer glands are respectively arranged outside the two groups of bearings and are sleeved with the central shaft through dust-proof rings. The outer glands are fixedly connected to the corresponding end covers and inner glands by bolts.

[0013] It further includes a sensor assembly, which includes a sensor base, an encoder, a shading disc and a sensor cover. The sensor base is arranged on the outer side of one group of the outer gland covers and fixedly connected to the corresponding outer gland cover. The encoder is arranged on one side of the sensor base and fixedly connected to the sensor base. The shading disc is arranged on the outer side of the encoder and sleeved on the central shaft through an elastic retaining ring. The sensor cover is arranged on one side of the end cover corresponding to the shading disc and fixedly connected to the end cover through bolts. The sensor cover covers the outer side of the shading disc.

[0014] The shaft end module includes a shaft end fan blade and an extended air duct cover. The shaft end fan blade is arranged on the side of one end of the central shaft close to the sensor cover and sleeved on the central shaft through an elastic retaining ring. The extended air duct cover is arranged on one end of the machine shell corresponding to the shaft end fan blade and fixedly connected to the machine shell. The extended air duct cover covers the outer side of the shaft end fan blade and has ventilation holes corresponding to the shaft end fan blade.

[0015] It further includes a lifting ring, which is arranged on the upper end of the machine shell and fixedly connected to the machine shell.

[0016] The beneficial effects of the present utility model are as follows:

[0017] There is a stator-rotor module. By changing the stator-rotor sheet type, the consumption of stator-rotor materials is reduced, the amount of copper wire used is decreased, and the torque index is improved. On the premise that the use technical indexes remain unchanged, the materials of the original designed motor are reduced, and the manufacturing cost is lowered. The control method of switched reluctance modeling is adopted, which comprehensively improves the control accuracy and the optimization of low-speed torque. At the same time, the low-speed pulsation is reduced, the reliability and processing capacity of the equipment are improved, thereby enhancing the reliability of the traction system during the operation of the pumping unit under the long-term low-speed heavy-load working conditions, fundamentally solving the continuous impact damage to the motor and the control unit under the periodic load caused by the long-term low-speed heavy-load operation of the current oilfield pumping unit, and improving the stability of the equipment operation. Description of the Drawings

[0018] Figure 1 is the overall structural schematic diagram of the first embodiment of the present utility model;

[0019] Figure 2 is the matching schematic diagram of the rotor sheet and the stator sheet of the first embodiment of the present utility model;

[0020] Figure 3 is the structural schematic diagram of the rotor sheet of the first embodiment of the present utility model;

[0021] Figure 4 is the structural schematic diagram of the stator sheet of the first embodiment of the present utility model;

[0022] Figure 5It is a matrix current comparison diagram of the driving motor of the present utility model and the driving motor in the prior art;

[0023] Figure 6 It is a motor parameter diagram of the driving motor in the prior art;

[0024] Figure 7 It is a motor parameter diagram of the driving motor of the present utility model;

[0025] Figure 8 It is a rated design parameter table of the driving motor in the prior art;

[0026] Figure 9 It is a rated design parameter table of the driving motor of the present utility model;

[0027] Figure 10 It is a flux linkage analysis diagram of the driving motor in the prior art;

[0028] Figure 11 It is a flux linkage analysis diagram of the driving motor of the present utility model.

[0029] In the figure: 1. Machine shell; 2. Central shaft; 3. Rotor sheet; 4. Stator sheet; 5. Coil; 6. Installation groove; 7. Inner pressure cover; 8. End cover; 9. Bearing; 10. Outer pressure cover; 11. Sensor seat; 12. Encoder; 13. Shading disc; 14. Sensor cover; 15. Axial end fan blade; 16. Extended air hood; 17. Lifting ring. Specific embodiments

[0030] The following further describes the present utility model in detail with reference to the accompanying drawings.

[0031] Embodiment 1:

[0032] A DC servo driving motor for a pumping unit includes a machine shell 1 and a central shaft 2. The central shaft 2 is coaxially arranged with the machine shell 1. It further includes a stator-rotor module for driving the central shaft 2 to rotate, an installation module for installing and positioning the stator-rotor module, and an axial end module for constituting the functional part of the motor shaft end. The stator-rotor module is arranged in the middle inside of the machine shell 1, the installation module is assembled at the end of the machine shell 1, and the axial end module is configured at one end of the central shaft 2. The overall structural schematic diagram of Embodiment 1 of the present utility model is as shown in Figure 1 shown.

[0033] The stator-rotor module includes a rotor sheet 3, a stator sheet 4, and a coil 5. The rotor sheet 3 is sleeved on the outer side of the middle part of the central shaft 2 and is key-connected to the central shaft 2. The stator sheet 4 is arranged on the outer side of the rotor sheet 3 and is sleeved with the rotor sheet 3. The coil 5 is arranged on the side part of the stator sheet 4 and is wound around the stator sheet 4. The stator-rotor module forms the stator-rotor structure in the drive motor through the cooperation of the rotor sheet 3, the stator sheet 4, and the coil 5. Among them, the rotor sheet 3 is used to rotate under the action of the stator sheet 4 and the coil 5, so as to drive the central shaft 2 to rotate. The stator sheet 4 is used to jointly form a drive magnetic field with the coil 5. The coil 5 is used to jointly form a stator winding structure with the stator sheet 4. The schematic diagram of the cooperation between the rotor sheet 3 and the stator sheet 4 in the first embodiment of the present utility model is as Figure 2 shown.

[0034] A number of groups of salient pole structures are evenly arranged on the outer peripheral part of the rotor sheet 3. The root part of the salient pole of the rotor sheet 3 is set as an arc-shaped fillet structure, and salient pole groove structures are symmetrically arranged on both sides of the tip part of the salient pole of the rotor sheet 3. Among them, the root part of the salient pole of the rotor sheet 3 is set as an arc-shaped fillet structure to increase the magnetic flux passing area of the rotor sheet 3 and increase the round and wide area between the shaft hole and the salient pole, so as to increase the mechanical inertia during rotor rotation and improve the motor torque index. The schematic diagram of the structure of the rotor sheet 3 in the first embodiment of the present utility model is as Figure 3 shown.

[0035] A number of groups of recessed pole structures are evenly arranged on the inner side of the stator sheet 4. The space between the several groups of recessed poles of the stator sheet 4 is set as a right-angle groove structure, and recessed pole groove structures are symmetrically arranged on both sides of the tip part of the recessed pole of the stator sheet 4. Among them, the space between the several groups of recessed poles of the stator sheet 4 is set as a right-angle groove structure to increase the number of slot poles and the full-slot rate at the same time. It can reduce the mechanical step angle number during motor operation, thereby reducing low-speed pulsation. The schematic diagram of the structure of the stator sheet 4 in the first embodiment of the present utility model is as Figure 4 shown.

[0036] It further includes mounting grooves 6. There are several groups of mounting grooves 6, and the several groups of mounting grooves 6 are evenly arranged around the outer peripheral part of the stator sheet 4. Among them, the mounting grooves 6 are used as the mounting structure on the outer side of the stator sheet 4 to meet the mounting requirements of the stator sheet 4, and improve the magnetic flux by increasing the magnetic induction intensity and the cross-sectional area of the stator-rotor magnetic path, so as to improve the current density and the effective current capacity.

[0037] The installation module includes an inner gland 7 and an end cover 8. There are two sets of inner glands 7, which are symmetrically arranged at both ends of the central shaft 2 and sleeved on the central shaft 2. The two sets of inner glands 7 are located on both sides of the stator-rotor module. There are two sets of end covers 8, which are symmetrically arranged at both ends of the housing 1 and fixedly connected to the housing 1. The two sets of end covers 8 are respectively located outside the two sets of inner glands 7. The installation module is combined with the inner gland 7 and the end cover 8 to form an installation structure at the end of the drive motor. Among them, the inner gland 7 is used as an installation structure at the inner end of the drive motor to install and position the stator-rotor module, and the end cover 8 is used to form an installation structure at the end of the drive motor to install the inner gland 7.

[0038] It also includes two sets of bearings 9 and two sets of outer glands 10. The two sets of bearings 9 are respectively arranged outside the two sets of inner glands 7 and sleeved on the central shaft 2. The bearings 9 are located inside the corresponding end covers 8. The two sets of outer glands 10 are respectively arranged outside the two sets of bearings 9 and sleeved on the central shaft 2 through dust-proof rings. The outer glands 10 are fixedly connected to the corresponding end covers 8 and inner glands 7 by bolts. Among them, the bearings 9 are used to provide rotational support for the central shaft 2, and the outer glands 10 are used to install and position the bearings 9.

[0039] It also includes a sensor assembly. The sensor assembly includes a sensor base 11, an encoder 12, a shading disc 13 and a sensor cover 14. The sensor base 11 is arranged outside one of the outer glands 10 and fixedly connected to the corresponding outer gland 10. The encoder 12 is arranged on one side of the sensor base 11 and fixedly connected to the sensor base 11. The shading disc 13 is arranged outside the encoder 12 and sleeved on the central shaft 2 through a snap ring. The sensor cover 14 is arranged on one side of the end cover 8 corresponding to the shading disc 13 and fixedly connected to the end cover 8 by bolts. The sensor cover 14 covers the outside of the shading disc 13. The sensor assembly is combined with the sensor base 11, the encoder 12, the shading disc 13 and the sensor cover 14 to form a signal conversion module in the drive motor. Among them, the sensor base 11 is used to provide an installation support for the encoder 12 to install the encoder 12 on the drive motor, the encoder 12 is used to convert signals, the shading disc 13 is used to block light to control the on-off of the drive motor, and the sensor cover 14 is used to shield and protect the sensor base 11, the encoder 12 and the shading disc 13.

[0040] The shaft-end module includes a shaft-end fan 15 and an extended air hood 16. The shaft-end fan 15 is arranged on the side of one end of the central shaft 2 close to the sensor hood 14 and is sleeved with the central shaft 2 through a circlip. The extended air hood 16 is arranged corresponding to the shaft-end fan 15 at one end of the housing 1 and is fixedly connected to the housing 1. The extended air hood 16 covers the outside of the shaft-end fan 15 and has ventilation holes corresponding to the shaft-end fan 15. The shaft-end module is configured to meet the ventilation and cooling requirements of the drive motor through the cooperation of the shaft-end fan 15 and the extended air hood 16. Among them, the shaft-end fan 15 is used to rotate with the central shaft 2 to meet the ventilation and cooling requirements of the drive motor, and the extended air hood 16 is used to cover and protect the corresponding end parts of the shaft-end fan 15 and the central shaft 2.

[0041] It further includes a lifting ring 17. The lifting ring 17 is arranged at the upper end of the housing 1 and is fixedly connected to the housing 1. Among them, the lifting ring 17 is used as a lifting structure on the drive motor to meet the lifting requirements of the drive motor.

[0042] Embodiment 2:

[0043] Among them, the relevant parameters of the drive motor in this embodiment are as follows:

[0044] Rated speed: 1000 rpm; Rated power: 37 KW; Rated voltage: DC514V; Rated current: 73 A; Rated torque: 353 N / m.

[0045] Among them, the comparison of the design parameters between the drive motor of the present utility model and the drive motor in the prior art is shown in Table 1 below:

[0046] Table 1

[0047]

[0048] Among them, the matrix current comparison diagram of the two is as Figure 5 shown.

[0049] Among them, the motor parameters of the drive motor in the prior art and the drive motor of the present utility model are as Figure 6 、 7 shown.

[0050] It can be seen from the comparison of the above two design parameters that:

[0051]

[0052] Among them, for the comparison of the design performance indicators, the rated design parameter table is as Figure 8 、 9 shown.

[0053] Among them, the flux linkage analysis diagrams of the two are as Figure 10 、 11 shown.

[0054] In summary, compared with the drive motors in the prior art, for the drive motor of the present utility model, the materials of the motor stator and rotor are each reduced by 23%, the amount of copper wire used is reduced by 35%, the torque index is increased by 17%, and the switched reluctance modeling control method is adopted to comprehensively improve the control accuracy and low-speed torque optimization. At the same time, the low-speed pulsation is reduced, and the reliability and processing capacity of the equipment are improved.

[0055] Working principle:

[0056] By changing the shapes of the stator and rotor laminations of this drive motor, it is intended to increase the magnetic flux when the energized phase of the stator and rotor is magnetized under the condition that the motor has not reached magnetic saturation. The root of the rotor salient pole is designed as a rounded corner to increase the magnetic flux passing area. By increasing the magnetic induction intensity B and the cross-sectional area S of the magnetic path of the stator and rotor, the magnetic flux Φ is increased, thereby increasing the current density and the effective current capacity. The design of the rotor increases the circular area between the shaft hole and the salient pole, which is intended to increase the mechanical inertia during the rotation of the rotor, improve the torque index of the motor, reduce the low-speed pulsation, and improve the reliability and processing capacity of the equipment.

[0057] The beneficial effects of the present utility model are that it is provided with a stator-rotor module. By changing the shapes of the stator and rotor laminations, the consumables of the stator and rotor are reduced, the amount of copper wire used is reduced, and the torque index is increased. Without changing the usage technical indicators, the materials of the original designed motor are reduced, and the manufacturing cost is reduced. The switched reluctance modeling control method is adopted to comprehensively improve the control accuracy and low-speed torque optimization. At the same time, the low-speed pulsation is reduced, and the reliability and processing capacity of the equipment are improved, thereby improving the reliability of the traction system during the long-term low-speed heavy-load operation of the pumping unit, fundamentally solving the continuous impact damage to the motor and the control unit under the periodic load caused by the long-term low-speed heavy-load operation of the current oilfield pumping units, and improving the stability of the equipment operation.

[0058] A detailed description of an embodiment of the present utility model has been given above, but the content is only the preferred embodiment of the present utility model and cannot be considered as limiting the scope of implementation of the present utility model. All equivalent changes and improvements made according to the scope of the application of the present utility model should still fall within the scope covered by the patent of the present utility model.

Claims

1. A DC servo drive motor for a pumping unit, comprising a housing (1) and a central shaft (2), wherein the central shaft (2) is coaxially arranged with the housing (1), characterized in that, It also includes a stator-rotor module for driving the rotation of the central shaft (2), a mounting module for mounting and positioning the stator-rotor module, and a shaft-end module for constituting the functional part of the motor shaft end. The stator-rotor module is arranged in the middle inside of the housing (1), the mounting module is assembled at the end of the housing (1), and the shaft-end module is configured at one end of the central shaft (2). The stator-rotor module includes a rotor sheet (3), a stator sheet (4), and a coil (5). The rotor sheet (3) is sleeved on the outer side of the middle part of the central shaft (2) and is key-connected to the central shaft (2). The stator sheet (4) is arranged on the outer side of the rotor sheet (3) and is sleeved with the rotor sheet (3). The coil (5) is arranged on the side part of the stator sheet (4) and is wound around the stator sheet (4).

2. The DC servo drive motor for a pumping unit according to claim 1, wherein, A number of groups of salient pole structures are evenly arranged on the outer peripheral part of the rotor sheet (3). The root of the salient pole of the rotor sheet (3) is set as an arc-shaped fillet structure, and salient pole groove structures are symmetrically arranged on both sides of the end of the salient pole of the rotor sheet (3).

3. The DC servo drive motor for a pumping unit according to claim 2, wherein, A number of groups of recessed pole structures are evenly arranged on the inner side of the stator sheet (4). A right-angle groove structure is arranged between the several groups of recessed poles of the stator sheet (4), and recessed pole groove structures are symmetrically arranged on both sides of the end of the recessed pole of the stator sheet (4).

4. The DC servo drive motor for a pumping unit according to claim 3, characterized in that It also includes mounting grooves (6). There are several groups of the mounting grooves (6), and the several groups of mounting grooves (6) are evenly arranged around the outer peripheral part of the stator sheet (4).

5. The DC servo drive motor for a pumping unit according to claim 4, characterized in that, The mounting module includes an inner gland (7) and an end cover (8). There are two groups of the inner gland (7), and the two groups of inner glands (7) are symmetrically arranged at both ends of the central shaft (2) and are sleeved with the central shaft (2). The two groups of inner glands (7) are located on both sides of the stator-rotor module. There are two groups of the end cover (8), and the two groups of end covers (8) are symmetrically arranged at both ends of the housing (1) and are fixedly connected to the housing (1). The two groups of end covers (8) are respectively located outside the two groups of inner glands (7).

6. The DC servo drive motor for a pumping unit according to claim 5, wherein, It also includes bearings (9) and outer glands (10). There are two groups of the bearings (9), and the two groups of bearings (9) are respectively arranged on the outer sides of the two groups of inner glands (7) and are sleeved with the central shaft (2). The bearings (9) are located inside the corresponding end covers (8). There are two groups of the outer glands (10), and the two groups of outer glands (10) are respectively arranged on the outer sides of the two groups of bearings (9) and are sleeved with the central shaft (2) through dust-proof rings. The outer glands (10) are fixedly connected to the corresponding end covers (8) and the inner glands (7) by bolts.

7. The DC servo drive motor for a pumping unit according to claim 6, wherein It further includes a sensor assembly, and the sensor assembly includes a sensor base (11), an encoder (12), a shading disc (13), and a sensor cover (14). The sensor base (11) is arranged on the outer side of one set of the outer gland (10) and fixedly connected to the corresponding outer gland (10). The encoder (12) is arranged on one side of the sensor base (11) and fixedly connected to the sensor base (11). The shading disc (13) is arranged on the outer side of the encoder (12) and sleeved on the central shaft (2) through a circlip. The sensor cover (14) is arranged on one side of the end cover (8) corresponding to the shading disc (13) and fixedly connected to the end cover (8) through bolts. The sensor cover (14) covers the outer side of the shading disc (13).

8. The DC servo drive motor for a pumping unit according to claim 7, wherein, The shaft end module includes a shaft end fan blade (15) and an extended air hood (16). The shaft end fan blade (15) is arranged on the side of one end of the central shaft (2) close to the sensor cover (14) and sleeved on the central shaft (2) through a circlip. The extended air hood (16) is arranged on one end of the machine shell (1) corresponding to the shaft end fan blade (15) and fixedly connected to the machine shell (1). The extended air hood (16) covers the outer side of the shaft end fan blade (15), and the extended air hood (16) is provided with ventilation holes corresponding to the shaft end fan blade (15).

9. The DC servo drive motor for a pumping unit according to claim 8, wherein It further includes a lifting ring (17), and the lifting ring (17) is arranged on the upper end of the machine shell (1) and fixedly connected to the machine shell (1).

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