An impeller for a centrifugal pump with adjustable vane included angle and a centrifugal pump

Abstract

The present invention discloses an impeller for a centrifugal pump with adjustable blade wrap angle, which comprises a central shaft and a plurality of blades. The radial inner end of each blade is hinged with the central shaft in a matching manner, and a diameter-adjusting blade is installed on the radial outer end of each blade. The central shaft is provided with an inner cavity, and a left angle-adjusting slider, a right angle-adjusting slider and a diameter-adjusting slider are slidably arranged along the axial direction in the inner cavity. The diameter-adjusting blades on each blade are connected to the diameter-adjusting slider through diameter-adjusting ropes. On the left and right sides of the radial inner end of each blade, a left angle-adjusting rope and a right angle-adjusting rope are respectively arranged. One end of the left angle-adjusting rope is connected to the left side, and the other ends of the left angle-adjusting ropes are all connected to the left angle-adjusting slider. One end of the right angle-adjusting rope is connected to the right side, and the other ends of the right angle-adjusting ropes are all connected to the right angle-adjusting slider. Through the above settings, the real-time adjustment of the blade wrap angle can be realized without changing the outer dimensions of the impeller, thereby increasing the operating condition range of the centrifugal pump. The present invention also discloses a centrifugal pump.

Description

Technical Field

[0001] The invention relates to the field of pump body impeller structures, and in particular to an impeller for a centrifugal pump with adjustable blade wrap angle.

[0002] The invention relates to the field of pump body impeller structures, and in particular to a centrifugal pump with adjustable blade wrap angle. Background Art

[0003] The centrifugal pump is an important fluid conveying machine, which is widely used in many fields such as energy extraction, agricultural irrigation, petrochemical industry, water conservancy projects, and urban water use. As an important flow-through component of the centrifugal pump, the impeller's blade shape and hydraulic parameters are the main parameters affecting the performance of the centrifugal pump. The blade wrap angle is one of the important parameters. The size of the blade wrap angle directly affects the hydraulic loss, flow conditions, cavitation characteristics, etc. of the pump. Many studies have found that according to different operating conditions, when the basic outer dimensions of the impeller are determined, there is an optimal wrap angle for the centrifugal pump. However, the blade wrap angles of existing centrifugal pumps are fixed, and can only achieve optimal performance under certain specific conditions. Therefore, it is of great significance to design an impeller with an adjustable blade wrap angle to increase the operating range of the centrifugal pump by adjusting the blade wrap angle to improve the performance of the centrifugal pump. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides an impeller for a centrifugal pump with an adjustable blade wrap angle, which can achieve real-time adjustment of the blade wrap angle without changing the outer dimensions of the impeller, thereby increasing the operating range of the centrifugal pump.

[0005] To achieve the above-mentioned purpose, the present invention provides an impeller for a centrifugal pump with an adjustable blade wrap angle, comprising a central axis and a plurality of blades, the plurality of blades being evenly distributed around the circumference of the central axis, the radial inner end of each blade being hingedly matched with the central axis, the radial outer end of each blade being provided with a diameter-adjusting blade, the central axis being provided with an inner cavity, and a left angle-adjusting slider, a right angle-adjusting slider and a diameter-adjusting slider being axially slidably arranged in the inner cavity, the left angle-adjusting slider being connected to a left power source driving it to slide axially in the inner cavity, and the right angle-adjusting slider being connected to a left power source driving it to slide axially in the inner cavity It is connected to a right power source for driving it to slide axially in the inner cavity, and the diameter adjusting slider is connected to a diameter adjusting power source for driving it to slide axially in the inner cavity. The diameter adjusting blades on each blade are connected to the diameter adjusting slider through a diameter adjusting rope, and a left angle adjustment rope and a right angle adjustment rope are respectively provided on the left and right sides of the radial inner end of each blade, one end of the left angle adjustment rope is connected to the left side of the corresponding blade, and the other end of each left angle adjustment rope is connected to the left angle adjustment slider, one end of the right angle adjustment rope is connected to the right side of the corresponding blade, and the other end of each right angle adjustment rope is connected to the right angle adjustment slider.

[0006] The present invention can be further configured such that a channel is formed on the blade for a corresponding diameter-adjusting rope to pass through, the channel penetrates the radially inner end of the blade, a slot for inserting a diameter-adjusting blade is formed at the radially outer end of the blade, one end of the slot penetrates the radially outer end of the blade, the other end of the slot communicates with the channel, a compression spring for urging the diameter-adjusting blade to extend radially outward from the slot is connected to the diameter-adjusting blade, a lug for preventing the diameter-adjusting blade from detaching from the blade is correspondingly arranged on the diameter-adjusting blade, the diameter-adjusting rope passes around an axially adjusting pulley, both the left and right angle-adjusting ropes pass around an axially adjusting pulley and a radially adjusting pulley, and both the axially adjusting pulley and the radially adjusting pulley are rotatably installed on the central shaft.

[0007] The present invention can also be further configured such that the compression spring is sleeved on the diameter-adjusting rope, and a groove for positioning the compression spring is formed in the slot. Such a setting can achieve better installation and positioning of the compression spring, and the structure is more stable and reliable.

[0008] The working principle of the present invention is as follows: According to the definition of the blade wrap angle, the angle between the line connecting the inlet edge (radially inner end) of the blade and the center of the circle and the line connecting the outlet edge (radially outer end) of the blade and the center of the circle is called the blade wrap angle. When the blade deflects, since the deflection center is not the center of the circle, the blade wrap angle will change accordingly, and the outer diameter of the impeller will also change accordingly. Therefore, by controlling the deflection angle and length of the blade, the change of the blade wrap angle can be controlled without changing the outer dimensions of the impeller. Specific operations are as follows: For example, by controlling the right power source to control the right angle-adjusting slider to translate to the right, and then pulling the blade through the right angle-adjusting rope, and controlling the left power source to control the left angle-adjusting slider to translate to the left, and then controlling the left angle-adjusting rope not to hinder the movement of the blade. Then, under the action of different angle-adjusting ropes, the blade is pulled to rotate clockwise (the observation direction is the back side of the impeller) by an angle, realizing an increase in the blade wrap angle, and the outer diameter of the impeller is also changed. At the same time, by controlling the diameter-adjusting power source to control the diameter-adjusting slider to translate to the left, and then controlling the diameter-adjusting rope to relax, the compression spring will push the diameter-adjusting blade to reset outward due to the decrease in the tension of the diameter-adjusting rope, making the blade longer, so as to keep the outer diameter of the impeller unchanged, that is, realizing the real-time adjustment of the blade wrap angle without changing the outer dimensions of the impeller.

[0009] The beneficial effects of the present invention are as follows: By adopting the above structure, the present invention optimizes the installation method of the impeller blades, which can realize the real-time change of the blade wrap angle, so that the centrifugal pump using the present invention can adjust the blade wrap angle in real time without replacing the impeller, thereby increasing the applicable range of the centrifugal pump. In addition, the present invention is also applicable to the impeller test experiment with variable wrap angles.

[0010] The present invention can also be further configured such that the displacement X of the diameter-adjusting slider 1 is obtained through the following formula

[0011]

[0012] where: R1 is the inner radius of the impeller; R 2 is the outer radius of the impeller; θ is the increased included angle;

[0013] The blade deflection angle α is determined by the following formula:

[0014]

[0015] The displacement L of the hinge point of the blade and the central axis 2 is determined by the following formula:

[0016]

[0017] In the formula: L 3 is the distance from the hinge point of the blade and the central axis to the blade deflection center;

[0018] The displacement X of the right angle adjustment slider 2 and the displacement X of the left angle adjustment slider 3 are determined by the following formula:

[0019]

[0020]

[0021] In the formula: L 1 is the distance from the hinge point of the blade and the central axis to the center of the radial alignment pulley in the initial position; β is the included angle formed at the connection of the left or right angle adjustment rope and the blade in the initial position, and the included angle is an acute angle.

[0022] By adopting the above formula, each power source can push the corresponding slider to slide a corresponding displacement, and can accurately adjust and control the change of the included angle according to the requirement. In addition, through the above formula derivation, the maximum included angle that can be adjusted within 90° blade deflection is arccos(R 1 / R 2 ).

[0023] The present invention can further be arranged such that radial protrusions are provided on both the left angle adjustment slider, the right angle adjustment slider and the diameter adjustment slider, and linear chutes are correspondingly formed on the inner cavity of the central axis to form a plug-in fit with the radial protrusions and allow the radial protrusions to slide therein. Such an arrangement makes the sliding of each slider more stable and reliable.

[0024] The present invention can further be arranged such that the central axis includes a shaft body and a head, the inner cavity is formed in the shaft body, and one axial end of the shaft body has an opening communicating with the inner cavity, the head is detachably and fixedly installed on the shaft body and covers the opening, and the blade is installed on the head. Such an arrangement enables each power source and slider to be inserted into the inner cavity through the opening, with a simple structure and convenient installation.

[0025] The present invention can further be configured such that the end is composed of two connecting discs spliced together, and after the two connecting discs are spliced, they correspondingly form a clamping limit for the radially inner end of the blade. Such a setting not only facilitates the installation of the blade, but also forms a better installation positioning for the blade.

[0026] The present invention can further be configured such that the left power source, the right power source, and the diameter-adjusting power source are all stepping motors.

[0027] Aiming at the deficiencies of the prior art, the present invention provides a centrifugal pump with adjustable blade wrap angle, which can realize the real-time adjustment of the blade wrap angle without changing the outer dimensions of the impeller, thereby increasing the operating condition range of the centrifugal pump.

[0028] To achieve the above object, the present invention provides a centrifugal pump, including a pump casing and an impeller installed in the pump casing, characterized in that: the impeller adopts the aforementioned impeller.

[0029] The working principle of the present invention is as follows: According to the definition of the blade wrap angle, the angle between the line connecting the inlet edge (radially inner end) of the blade and the center of the circle and the line connecting the outlet edge (radially outer end) of the blade and the center of the circle is called the blade wrap angle. Then, when the blade deflects, since the deflection center is not the center of the circle, the blade wrap angle will change accordingly. Along with this change, the outer diameter of the impeller also changes. Therefore, by controlling the deflection angle and length of the blade, the change of the blade wrap angle can be controlled without changing the outer dimensions of the impeller. Specific operations are as follows: By controlling the right power source to control the right angle-adjusting slider to move rightward, and then pulling the blade through the right angle-adjusting rope, and the left power source controls the left angle-adjusting slider to move leftward, and then controls the left angle-adjusting rope not to hinder the movement of the blade. Then, under the action of different angle-adjusting ropes, the blade is pulled to rotate clockwise (the observation direction is the back side of the impeller) by an angle, realizing an increase in the blade wrap angle, and the outer diameter of the impeller is also changed. At the same time, by controlling the diameter-adjusting power source to control the diameter-adjusting slider to move leftward, and then controlling the diameter-adjusting rope to relax, the compression spring will push the diameter-adjusting blade to reset outward due to the decrease in the pulling force of the diameter-adjusting rope, making the blade longer, so as to keep the outer diameter of the impeller unchanged, that is, to realize the real-time adjustment of the blade wrap angle without changing the outer dimensions of the impeller. Brief Description of the Drawings

[0030] Figure 1 Is a three-dimensional view of the present invention;

[0031] Figure 2 Is an exploded view of the structure of the central shaft in the present invention;

[0032] Figure 3 Is the structure diagram of the present invention after removing the central shaft;

[0033] Figure 4 Is a partial structure diagram of the present invention;

[0034] Figure 5It is the structural decomposition diagram of the blade part in the present invention;

[0035] Figure 6 It is the partial structural diagram of the present invention;

[0036] Figure 7 It is the structural sectional view of the present invention;

[0037] Figure 8 It is the structural sectional view of the blade part in the present invention. Specific embodiments

[0038] Embodiment 1: As Figure 1-8 shown, an impeller for a centrifugal pump with adjustable blade wrap angle is given, including a central shaft 1 and several blades 2. The several blades 2 are arranged circumferentially and evenly around the central shaft 1. The radial inner end of each blade 2 forms a hinge fit with the central shaft 1. A diameter-adjusting blade 3 is installed on the radial outer end of each blade 2. The central shaft 1 is provided with an inner cavity 4, and a left angle-adjusting slider 5, a right angle-adjusting slider 6 and a diameter-adjusting slider 7 are slidably arranged axially in the inner cavity 4. A left power source 8 for driving the left angle-adjusting slider 5 to slide axially in the inner cavity 4 is connected to the left angle-adjusting slider 5. A right power source 9 for driving the right angle-adjusting slider 6 to slide axially in the inner cavity 4 is connected to the right angle-adjusting slider 6. A diameter-adjusting power source 10 for driving the diameter-adjusting slider 7 to slide axially in the inner cavity 4 is connected to the diameter-adjusting slider 7. The diameter-adjusting blade 3 on each blade 2 is connected to the diameter-adjusting slider 7 through a diameter-adjusting rope 11. On the left and right sides of the radial inner end of each blade 2, a left angle-adjusting rope 12 and a right angle-adjusting rope 13 are respectively arranged. One end of the left angle-adjusting rope 12 is connected to the left side of the corresponding blade 2, and the other ends of the left angle-adjusting ropes 12 are all connected to the left angle-adjusting slider 5. One end of the right angle-adjusting rope 13 is connected to the right side of the corresponding blade 2, and the other ends of the right angle-adjusting ropes 13 are all connected to the right angle-adjusting slider 6.

[0039] A channel 14 for the corresponding diameter-adjusting rope 11 to pass through is opened on the blade 2. The channel 14 penetrates the radial inner end of the blade 2. A slot 21 for inserting the diameter-adjusting blade 3 is opened at the radial outer end of the blade 2. One end of the slot 21 penetrates the radial outer end of the blade 2, and the other end of the slot 21 is communicated with the channel 14. A compression spring 15 for urging the diameter-adjusting blade 3 to radially extend out of the slot 21 is further connected to the diameter-adjusting blade 3. The compression spring 15 is sleeved on the diameter-adjusting rope 11, and a groove 26 for positioning the compression spring 15 is formed in the slot 21. A lug 16 for preventing the diameter-adjusting blade 3 from detaching from the blade 2 is correspondingly arranged on the diameter-adjusting blade 3. The diameter-adjusting rope 11 passes around an axially adjusting pulley 17, and both the left and right angle-adjusting ropes pass around the axially adjusting pulley 17 and a radially adjusting pulley 18. The axially adjusting pulley 17 and the radially adjusting pulley 18 are both rotatably installed on the central shaft 1.

[0040] The left angle-adjusting slider 5, the right angle-adjusting slider 6, and the diameter-adjusting slider 7 are all provided with radially protruding portions 19, and corresponding linear chutes 20 are opened on the inner cavity 4 of the central shaft, which form a plug-in fit with the radially protruding portions 19 and allow the radially protruding portions 19 to slide therein.

[0041] The above-mentioned left power source 8, right power source 9, and diameter-adjusting power source 10 are preferably stepper motors. Of course, other power mechanisms such as air cylinders can also be selected. In addition, each rope and pulley is only a transmission method in this embodiment, and a combination of gears and chains can also be used to replace it, which should not be understood as a limitation to the present invention.

[0042] By adopting the above structure, the present invention optimizes the installation method of the impeller blades, which can realize the real-time change of the blade wrap angle, so that the centrifugal pump using the present invention can adjust the blade wrap angle in real time without replacing the impeller, thereby increasing the applicable range of the centrifugal pump. In addition, the present invention is also applicable to the impeller test experiment with variable wrap angle.

[0043] The central shaft 1 includes a shaft body 22 and an end head 23. The inner cavity 4 is opened in the shaft body 22, and one axial end of the shaft body 22 has an opening 24 communicating with the inner cavity 4. The end head 23 is detachably fixed on the shaft body 22 and covers the opening 24. The blade 2 is installed on the end head 23. With this setting, each power source and slider can be installed into the inner cavity 4 through the opening 24, with a simple structure and convenient installation. The end head 23 is composed of two connecting plates 25 spliced together, and the two connecting plates 25 form a clamping limit for the radially inner end of the blade 2 after splicing. This setting not only facilitates the installation of the blade 2 but also forms better installation positioning for the blade 2.

[0044] The steps to adjust the blade wrap angle in this embodiment are as follows:

[0045] Step 1: Determine the model parameters of this embodiment. The inner radius R of the impeller is 40 mm; the outer radius R of the impeller is 245 mm; the initial wrap angle of the blade 2 is 0°; the distance L from the hinge point of the blade 2 and the central shaft 1 to the deflection center of the blade 2 is 15 mm; the distance L from the hinge point of the blade 2 and the central shaft 1 to the center of the radial adjustment pulley 18 in the initial position is 17 mm; the included angle (acute angle) β formed at the connection point of the left or right angle-adjusting rope and the blade 2 in the initial position is 87°. 1 for 40 mm; the outer radius R of the impeller 2 is 245 mm; the initial wrap angle of the blade 2 is 0°; the distance L from the hinge point of the blade 2 and the central shaft 1 to the deflection center of the blade 2 3 is 15 mm; the distance L from the hinge point of the blade 2 and the central shaft 1 to the center of the radial adjustment pulley 18 in the initial position 1 is 17 mm; the included angle (acute angle) β formed at the connection point of the left or right angle-adjusting rope and the blade 2 in the initial position is 87°.

[0046] Step 2: Determine the required wrap angle of the blade 2, set as 60°, then the increased wrap angle θ is 60°. Through the formula it can be calculated that X 1 = 22.65 mm. In this way, the diameter-adjusting power source 10 can correspondingly control the diameter-adjusting slider 7 to slide X1 Distance, that is, the adjusting diameter blade 3 is pushed outwards by the compression spring 15 by X 1 distance.

[0047] Step 3: According to the obtained X 1 The deflection angle α of the blade 2 can be determined to be 68.5°, and the calculation function is Furthermore, the displacement L of the hinge point of the blade 2 and the central axis 1 is determined 2 to be 16.88 mm, and the calculation function is

[0048] Step 4: According to the parameters obtained in Step 3, the displacement X of the right angle adjustment slider 6 can be correspondingly obtained 2 and the displacement X of the left angle adjustment slider 5 3 , and further control the blade 2 to deflect 68.5° to the right. It can be calculated that X 2 = 7.874 mm, X 3 = 15.1 mm. The calculation function is

[0049]

[0050]

[0051] By the above steps, the set blade wrap angle of 60° can be adjusted without changing the outer diameter of the blade. The maximum wrap angle that can be achieved in the ideal case of this embodiment is 80.6°, and the calculation function is arccos(R 1 / R 2 ).

[0052] Embodiment 2: What this embodiment protects is a centrifugal pump, which includes a pump casing and an impeller installed in the pump casing, and the impeller adopts the impeller disclosed in Embodiment 1.

Claims

1. An impeller for a centrifugal pump with adjustable blade wrap angle, comprising a central shaft and a plurality of blades. The plurality of blades are circumferentially and evenly arranged around the central shaft. It is characterized in that: The radially inner end of each blade is hinged to the central shaft in a mating manner. A diameter-adjusting blade is installed on the radially outer end of each blade. The central shaft is provided with an inner cavity, and a left angle-adjusting slider, a right angle-adjusting slider and a diameter-adjusting slider are axially slidably arranged in the inner cavity. A left power source for driving the left angle-adjusting slider to axially slide in the inner cavity is connected to the left angle-adjusting slider. A right power source for driving the right angle-adjusting slider to axially slide in the inner cavity is connected to the right angle-adjusting slider. A diameter-adjusting power source for driving the diameter-adjusting slider to axially slide in the inner cavity is connected to the diameter-adjusting slider. The diameter-adjusting blade on each blade is connected to the diameter-adjusting slider through a diameter-adjusting rope. On the left and right sides of the radially inner end of each blade, a left angle-adjusting rope and a right angle-adjusting rope are respectively arranged. One end of the left angle-adjusting rope is connected to the left side of the corresponding blade, and the other ends of the left angle-adjusting ropes are all connected to the left angle-adjusting slider. One end of the right angle-adjusting rope is connected to the right side of the corresponding blade, and the other ends of the right angle-adjusting ropes are all connected to the right angle-adjusting slider.

2. The impeller for a centrifugal pump with adjustable blade wrap angle according to claim 1, It is characterized in that: A channel through which the corresponding diameter-adjusting rope passes is opened on the blade. The channel penetrates the radially inner end of the blade. A slot for inserting the diameter-adjusting blade is opened at the radially outer end of the blade. One end of the slot penetrates the radially outer end of the blade, and the other end of the slot is communicated with the channel. A compression spring for urging the diameter-adjusting blade to radially extend out of the slot is further connected to the diameter-adjusting blade. Lugs for preventing the diameter-adjusting blade from detaching from the blade are correspondingly arranged on the diameter-adjusting blade. The diameter-adjusting rope passes around an axially adjusting pulley, and both the left and right angle-adjusting ropes pass around an axially adjusting pulley and a radially adjusting pulley. The axially adjusting pulley and the radially adjusting pulley are both rotatably installed on the central shaft.

3. The impeller for a centrifugal pump with adjustable blade wrap angle according to claim 2, It is characterized in that: The compression spring is sleeved on the diameter-adjusting rope, and a groove for positioning the compression spring is formed in the slot.

4. The impeller for a centrifugal pump with adjustable blade wrap angle according to claim 2, It is characterized in that: The displacement X of the diameter-adjusting slider 1 is obtained by the following formula Where: R 1 is the inner radius of the impeller; R 2 is the outer radius of the impeller; θ is the increased included angle; The deflection angle α of the blade is determined by the following formula: The displacement L of the hinge point between the blade and the central axis 2 is determined by the following formula: Where: L 3 is the distance from the hinge point of the blade and the central axis to the deflection center of the blade; The displacement X of the right angle-adjusting slider 2 and the displacement X of the left angle-adjusting slider 3 are determined by the following formula: Where: L 1 is the distance from the hinge point of the blade and the central axis at the initial position to the center of the radial alignment pulley; β is the angle formed at the connection of the left or right angle adjustment rope and the blade at the initial position, and the angle is an acute angle.

5. The impeller for a centrifugal pump with adjustable blade wrap angle according to claim 1 or 2 or 3 or 4, It is characterized in that: Radially protruding portions are provided on the left angle-adjusting slider, the right angle-adjusting slider and the diameter-adjusting slider. Corresponding linear chutes for forming a plug-in fit with the radially protruding portions and for the radially protruding portions to slide therein are opened on the inner cavity of the central shaft.

6. The impeller for a centrifugal pump with adjustable blade wrap angle according to claim 1 or 2 or 3 or 4, It is characterized in that: The central shaft includes a shaft body and a head. The inner cavity is opened in the shaft body, and one axial end of the shaft body has an opening communicating with the inner cavity. The head is detachably and fixedly installed on the shaft body and covers the opening. The blade is installed on the head.

7. The impeller for a centrifugal pump with adjustable blade wrap angle according to claim 6, It is characterized in that: The end is composed of two connecting plates spliced together, and after the two connecting plates are spliced, they correspondingly form clamping and limiting for the radially inner ends of the blades.

8. An impeller for a centrifugal pump with adjustable blade wrap angle according to claim 1 or 2 or 3 or 4, characterized in that: The left power source, the right power source, and the diameter-adjusting power source are all stepper motors.

9. A centrifugal pump, comprising a pump casing and an impeller installed in the pump casing, characterized in that: The impeller adopts the impeller of any one of claims 1 to 8.

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