Speed-adjustable oil-immersed axial flow oil pump and control method thereof

Abstract

The invention discloses an axial-flow oil-submerged pump device, and aims to provide a speed-adjustable oil-immersed axial-flow oil pump which is not easy to damage, low in processing difficulty and convenient to adjust the rotating speed of a motor and a control method of the speed-adjustable oil-immersed axial-flow oil pump. The technical scheme is characterized in that the whole motor is directly pressed into a limiting step of a pump body through a press, the installation is convenient, and the whole pump body is arranged in a sealed manner; the motor is arranged in the pump body, the motor is protected by the front cover and the rear cover, abrasion and collision to the motor in the operation process are effectively prevented, and the service life of the motor is prolonged. The service life of the motor is prolonged, the rotating speed of the motor in the pump body can be adjusted through the motor driving plate, the rotating speed is gradually increased along with rising of the temperature, the cooling effect can be better improved, and the axial flow pump is suitable for the field of design and manufacturing of the axial flow pump.

Description

Technical Field

[0001] The present invention relates to an axial flow submersible oil pump device, and more specifically, to an adjustable speed oil-immersed axial flow oil pump and a control method thereof. Background Art

[0002] Axial flow pump is a low head and large flow vane pump. Its blade-shaped wings are usually connected to the pipeline. After starting, the rotation of the impeller will drive the fluid medium in the pipeline to rotate axially. At the guide vane, the kinetic energy of the impeller to the fluid is converted into pressure energy, which flows out of the pump outlet and enters the lower pipeline. The oil-immersed axial flow oil pump is mainly composed of four parts: pump body, impeller, guide vane, and motor. The characteristic is that the motor is directly immersed in the medium oil.

[0003] At present, the existing oil-immersed axial flow oil pump usually needs to be realized through external speed control equipment such as frequency converters. However, it is difficult to use in its application scenarios, and in order to control the air gap of the motor, it usually requires a very high concentricity, high machining precision and great difficulty, and the bearing outside the pump body is easily damaged during operation. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide an adjustable speed oil-immersed axial flow oil pump and a control method thereof which is not easy to damage, has low processing difficulty, and is convenient for adjusting the motor speed.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: an adjustable speed oil-immersed axial flow oil pump and a control method thereof, comprising a front casing, a rear casing, an impeller, a motor and a pump body sleeved on the outside of the impeller and the motor, the motor comprising a motor outer casing and a motor, an inner cavity being provided in the motor outer casing, the rotating shaft being rotatably arranged in the inner cavity, and the impeller being inserted into the rotating shaft of the motor and fixed by an impeller nut, a limiting step being provided in the pump body, and the size of the limiting step being matched with the size of the motor, the motor being detachably connected to the pump body via the limiting step, and after the motor is installed on the limiting step of the pump body, the central axis of the motor coincides with the central axis of the pump body, and the rotating shafts of the impeller and the motor are located on the central axis.

[0006] By adopting the above technical solution, the motor is installed on the limiting step of the pump body, and the motor as a whole is directly pressed into the limiting step of the pump body by a press, which is easy to install, and the motor and the pump body have a compact structure. At the same time, the motor and the pump body are detachable and easy to replace, and the motor is not difficult to repair. The processing process only requires opening a groove on the pump body, and the processing is not difficult. After installation, the motor and the pump body are accurately positioned with high precision.

[0007] The present invention is further configured as follows: an air hole is provided on the pump body, a sealing plug is provided on the air hole, the pump body is sealed by the sealing plug, the motor and the pump body are connected by fasteners, an installation cavity is also provided in the pump body, a front cover and a rear cover for protecting the motor are also provided on the outside of the motor, the motor and the pump body are filled with insulating oil, and the insulating oil is configured to reduce the temperature of the motor during operation and to insulate the motor from the pump body.

[0008] By adopting the above technical solution, the pump body is sealed as a whole, which effectively prevents leakage of internal insulating oil. The insulating oil can automatically convect in the motor, can dissipate heat and cut off the fluidity required for arc current, thereby increasing the safety of the equipment during operation. The motor is arranged in the pump body and is protected by the front cover and the rear cover, which effectively prevents wear and collision of the motor during operation and extends the service life of the motor.

[0009] The present invention is further configured as follows: a motor drive board is provided on the outside of the pump, and the motor drive board is electrically connected to the motor for regulating the speed of the motor.

[0010] By adopting the above technical solution, the speed of the motor in the pump body can be adjusted through the motor drive board, and the speed gradually increases as the temperature rises, which can better improve the cooling effect.

[0011] A control method for an adjustable speed oil-immersed axial flow oil pump also includes a temperature detection device, which includes a thermometer and an analog-to-digital conversion module, and is used to detect the temperature and send a signal to a transformer cooler control box; a control system, which is used to control the start and stop of the oil pump and adjust the speed of the pump body; a flow detection device, which includes an electronic flow meter, and is used to detect the flow data in the pump body. The specific control steps are as follows:

[0012] S1. Set the rated temperature of the temperature detection device to 25°C, and detect the temperature at the same time. The detection time is T1;

[0013] S2. During the T1 period, the temperature detected by the temperature detection device is W1. If W1>40°C, the control system controls the motor to start, and the temperature detection device continues to detect the temperature for T2. Otherwise, the temperature detection device continues to detect the temperature.

[0014] S3. In the T2 time period, the temperature detection device measures the temperature as W2. If 40°C ≤ W2 ≤ 85°C, the control device gradually increases the speed R from 100 rpm to 960 rpm as the temperature increases, and jumps to S7 to continue working.

[0015] S4, if W2 is less than 40℃, the control device stops the motor and jumps back to S2 to continue detecting the temperature;

[0016] S5. If W2>85℃, the control device will control the whole equipment to alarm and increase the motor speed to cool the equipment;

[0017] S6. If W2>100℃, the control device will shut down the whole equipment and carry out maintenance;

[0018] S7, set the rated flow rate of the pump to Q; at the same time, the flow monitoring device detects the flow data, and the detection time is T3

[0019] S8. During the T3 time period, the flow detection device detects the flow data as Q1. If -5% of Q is less than Q1 and less than +5% of Q, the control device increases the rotation speed R by a small amount and continues to detect the flow Q2. The detection time is T4. Otherwise, it jumps back to S7 to continue detection.

[0020] S9. During the T4 time period, the flow detection device detects the flow data as Q2. If Q2>Q10%, the speed stops increasing. Otherwise, the process returns to S8 to continue detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A cross-sectional view of an embodiment of an adjustable speed oil-immersed axial flow oil pump and a control method thereof according to the present invention;

[0022] Figure 2 A control flow chart of an embodiment of an adjustable speed oil-immersed axial flow oil pump and a control method thereof according to the present invention;

[0023] The reference numerals in the figure are: 1. front casing; 2. rear casing; 3. impeller; 4. motor; 5. pump body; 6. motor outer casing; 7. rotating shaft; 8. inner cavity; 9. impeller nut; 10. limiting step; 11. air hole; 12. sealing plug; 13. fastener; 14. installation cavity; 15. front cover; 16. rear cover. DETAILED DESCRIPTION

[0024] Reference Figures 1 to 2 An embodiment of an adjustable speed oil-immersed axial flow oil pump and a control method thereof of the present invention is further described.

[0025] For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right" and the like are used in the embodiments to illustrate the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientation shown in the figure, the spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "on" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0026] Furthermore, relational terms such as “first” and “second” and the like are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0027] An adjustable speed oil-immersed axial flow oil pump and a control method thereof, comprising a liquid inlet, a liquid outlet, an impeller 3, a motor 4 rotatably connected to the impeller 3, and a pump body 5 sleeved on the outside of the impeller 3 and the motor 4, wherein the motor 4 comprises an outer shell of the motor 4 and a rotating shaft 7, wherein an inner cavity 8 is provided in the outer shell of the motor 4, wherein the rotating shaft 7 is rotatably arranged in the inner cavity 8, and the impeller 3 is inserted into the rotating shaft 7 of the motor 4 and fixed by a nut of the impeller 3, wherein a limiting step 10 is provided in the pump body 5, and the size of the limiting step 10 matches the size of the motor 4, The motor 4 is detachably connected to the pump body 5 through the limiting step 10. The motor 4 is directly pressed into the limiting step 10 of the pump body 5 by a press, which is easy to install. The motor 4 and the pump body 5 have a compact structure and are easy to replace. The motor 4 is easy to repair. The processing process only requires opening a groove on the pump body 5, and the processing is easy. After the motor 4 is installed on the limiting step 10 of the pump body 5, the central axis of the motor 4 coincides with the central axis of the pump body 5, and the impeller 3 and the rotating shaft 7 of the motor 4 are located on the central axis. After installation, the motor 4 and the pump body 5 are accurately positioned with high precision.

[0028] The pump body 5 is provided with an air hole 11, and the air hole 11 is provided with a sealing plug 12. The pump body 5 is closed by the sealing plug 12. The motor 4 is connected to the pump body 5 by a fastener 13. The pump body 5 is also provided with a mounting cavity 14. The outside of the motor 4 is also provided with a front cover 15 and a rear cover 16 for protecting the motor 4. The motor 4 is arranged in the pump body 5 and is protected by the front cover 15 and the rear cover 16, which effectively prevents the wear and collision of the motor 4 during operation, thereby extending the service life of the motor 4. The motor 4 and the pump body 5 are both filled with insulating oil. The pump body 5 is sealed as a whole to effectively prevent leakage of the internal insulating oil. The insulating oil is configured to reduce the temperature of the motor 4 during operation and to insulate the motor 4 from the pump body 5. The insulating oil can automatically convect in the motor 4, can extract heat and cut off the fluidity required for arc current, thereby increasing the safety of the equipment during operation.

[0029] A motor 4 drive board is provided on the outside of the motor 4, and the motor 4 drive board is electrically connected to the motor 4 for adjusting the speed of the motor 4. The speed of the motor 4 in the pump body 5 can be adjusted by the motor 4 drive board, and the speed gradually increases with the increase of temperature, which can better improve the cooling effect.

[0030] Reference Figure 2, a control method for an adjustable speed oil-immersed axial flow oil pump, further comprising a temperature detection device, the temperature detection device comprising a transformer cooling system control box for detecting temperature; a control system for controlling the start and stop of the oil pump and adjusting the speed of the pump body; a flow detection device comprising an electronic flow meter for detecting flow data in the pump body, and the specific control steps are as follows:

[0031] S1. Set the rated temperature of the temperature detection device to 25°C, and detect the temperature at the same time. The detection time is T1;

[0032] S2. During the T1 period, the temperature detected by the temperature detection device is W1. If W1>40°C, the control system controls the motor to start, and the temperature detection device continues to detect the temperature for T2. Otherwise, the temperature detection device continues to detect the temperature.

[0033] S3. In the T2 time period, the temperature detection device measures the temperature as W2. If 40°C ≤ W2 ≤ 85°C, the control device gradually increases the speed R from 100 rpm to 960 rpm as the temperature increases, and jumps to S7 to continue working.

[0034] S4, if W2 is less than 40℃, the control device stops the motor and jumps back to S2 to continue detecting the temperature;

[0035] S5. If W2>85℃, the control device will control the whole equipment to alarm and increase the motor speed to cool the equipment;

[0036] S6. If W2>100℃, the control device will shut down the whole equipment and carry out maintenance;

[0037] S7, set the rated flow rate of the pump to Q; at the same time, the flow monitoring device detects the flow data, and the detection time is T3

[0038] S8. During the T3 time period, the flow detection device detects the flow data as Q1. If -5% of Q is less than Q1 and less than +5% of Q, the control device increases the rotation speed R by a small amount and continues to detect the flow Q2. The detection time is T4. Otherwise, it jumps back to S7 to continue detection.

[0039] S9. During the T4 time period, the flow detection device detects the flow data as Q2. If Q2>Q10%, the speed stops increasing. Otherwise, the process returns to S8 to continue detection.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. An adjustable speed oil-immersed axial flow oil pump, characterized in that: The invention comprises a front casing (1), a rear casing (2), an impeller (3), a motor (4), and a pump body (5) sleeved on the outer sides of the impeller (3) and the motor (4); the motor (4) comprises an outer casing of the motor (4) and a rotating shaft (7); an inner cavity (8) is provided in the outer casing of the motor (4); the rotating shaft (7) is rotatably arranged in the inner cavity (8); the impeller (3) is inserted into the rotating shaft (7) of the motor (4) and fixed by a nut of the impeller (3); a limiting step (10) is provided in the pump body (5); the size of the limiting step (10) matches the size of the motor (4); the motor (4) is detachably connected to the pump body (5) via the limiting step (10).

2. The speed-adjustable oil-immersed axial flow oil pump according to claim 1, characterized in that: The pump body (5) is provided with an air hole (11), the air hole (11) is provided with a sealing plug (12), the pump body (5) is closed by the sealing plug (12), the motor (4) and the pump body (5) are connected by a fastener (13), a mounting cavity (14) is also provided in the pump body (5), and a front cover (15) and a rear cover (16) for protecting the motor (4) are also provided on the outside of the motor (4).

3. The speed-adjustable oil-immersed axial flow oil pump according to claim 2, characterized in that: A motor (4) drive plate is provided on the outside of the motor (4), and the motor (4) drive plate is electrically connected to the motor (4) and is used to adjust the speed of the motor (4).

4. The speed-adjustable oil-immersed axial flow oil pump according to claim 2, characterized in that: The motor (4) and the pump body (5) are both filled with insulating oil, and the insulating oil is configured to reduce the temperature of the motor (4) during operation and to insulate the motor (4) from the pump body (5).

5. The speed-adjustable oil-immersed axial flow oil pump according to claim 1, characterized in that: After the motor (4) is installed on the limiting step (10) of the pump body (5), the central axis of the motor (4) coincides with the central axis of the pump body (5), and the impeller (3) and the rotating shaft (7) of the motor (4) are located on the central axis.

6. A control method for an adjustable speed oil-immersed axial flow oil pump according to claim 1, characterized in that: It also includes a temperature detection device, which includes a transformer cooling system control box for detecting temperature; a control system for controlling the start and stop of the oil pump and adjusting the speed of the pump body; a flow detection device, including an electronic flow meter, for detecting flow data in the pump body. The specific control steps are as follows: S1. Set the rated temperature of the temperature detection device to 25°C, and detect the temperature at the same time. The detection time is T1; S2. During the T1 period, the temperature detected by the temperature detection device is W1. If W1>40°C, the control system controls the motor to start, and the temperature detection device continues to detect the temperature for T2. Otherwise, the temperature detection device continues to detect the temperature. S3. In the T2 time period, the temperature detection device measures the temperature as W2. If 40°C ≤ W2 ≤ 85°C, the control device gradually increases the speed R from 100 rpm to 960 rpm as the temperature increases, and jumps to S7 to continue working. S4, if W2 is less than 40℃, the control device stops the motor and jumps back to S2 to continue detecting the temperature; S5. If W2>85℃, the control device will control the whole equipment to alarm and increase the motor speed to cool the equipment; S6. If W2>100℃, the control device will shut down the whole equipment and carry out maintenance; S7, set the rated flow rate of the pump to Q, and the flow monitoring device detects the flow data at the same time, and the detection time is T3 S8. During the T3 time period, the flow detection device detects the flow data as Q1. If -5% of Q is less than Q1 and less than +5% of Q, the control device increases the rotation speed R by a small amount and continues to detect the flow Q2. The detection time is T4. Otherwise, it jumps back to S7 to continue detection. S9. During the T4 time period, the flow detection device detects the flow data as Q2. If Q2>Q10%, the speed stops increasing. Otherwise, the process returns to S8 to continue detection.

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