Efficient wear-resistant centrifugal gravel conveying pump

Abstract

The invention discloses a high-efficiency wear-resistant centrifugal gravel delivery pump, which belongs to the technical field of fluid delivery, and comprises a volute, a front end cover, a rear end cover and an impeller, the impeller is arranged in the volute, the axial surface of the impeller forms a smooth transition flow channel, and a plurality of blades are arranged on the impeller at intervals around the axis of the impeller; the bone surface of the blade is composed of a plurality of continuous spline curves in the extending direction of the blade, and the installation angle of the blade has at least one inflection point along the arc length changing curve of the bone surface. The front end cover is arranged at an inlet of the volute, and a sealing structure is formed between the inner surface of the front end cover and the volute. In conclusion, through the unique flow channel and blade design of the impeller and the sealing structure between the front end cover and the volute, the pumping effect on large-particle matter in ore pulp is effectively improved, the blocking risk is reduced, and the high-efficiency conveying requirement under the complex working condition can be better met.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid transportation, and in particular to a high-efficiency and wear-resistant centrifugal sand and gravel transportation pump. Background Art

[0002] In mining and mineral processing operations, large amounts of mixtures containing solid particles, such as slurry, mud, and waste, need to be transported to designated locations or discharged. Mining pumps, as key conveying equipment in these operations, play a vital role in ore mining, ore crushing, screening, and mineral processing.

[0003] Existing mining pumps typically feature straight or simple curved flow paths. These designs fail to fully account for the flow patterns and mechanical properties of large particles in the slurry. Consequently, large particles can easily create flow resistance as they pass through the pump, leading to particle deposition, flow reduction, and blockage. Particularly in slurries with high solids content and large particles, the flow capacity of conventional pumps is significantly insufficient, unable to meet the demands for efficient delivery under complex operating conditions. Furthermore, the flow passages within the pump are often not optimized for the flow characteristics of large particles, significantly reducing pump efficiency and even damaging the pump under heavy particle loads. Summary of the Invention

[0004] The object of the present invention is to provide a high-efficiency and wear-resistant centrifugal sand and gravel conveying pump to solve the technical problems in the prior art that mining pumps have poor pumping effect on large particles in ore slurry and are prone to clogging.

[0005] As conceived above, the technical solution adopted by the present invention is:

[0006] A high-efficiency and wear-resistant centrifugal sand and gravel conveying pump, comprising a volute, a front cover, a rear cover and an impeller, specifically:

[0007] The impeller is arranged in the volute, the axial surface of the impeller forms a smoothly transitioned flow channel, a plurality of blades are arranged at intervals around the axis of the impeller, the bone surface of the blade is composed of a plurality of continuous spline curves along its own extension direction, and the installation angle of the blade has at least one inflection point along the arc length change curve of the bone surface;

[0008] The front end cover is arranged at the inlet of the volute, and a sealing structure is formed between the inner surface of the front end cover and the volute.

[0009] Preferably, the bone surface is composed of three continuous spline curves along its own extension direction, namely the first spline curve, the second spline curve and the third spline curve. The first spline curve is located on the side of the blade close to the rear end cover, the inlet installation angle of the first spline curve is 38° to 40°, the outlet installation angle is 14° to 16°, and the wrap angle is 148° to 152°; the second spline curve is located in the middle position of the blade, the inlet installation angle of the second spline curve is 25° to 27°, the outlet installation angle is 14° to 16°, and the wrap angle is 149° to 153°; the third spline curve is located on the side of the blade close to the front end cover; the inlet installation angle of the third spline curve is 16° to 18°, the outlet installation angle is 14° to 16°, and the wrap angle is 150° to 154°.

[0010] Preferably, three blades are provided, and the angle between each two adjacent blades is 120 degrees.

[0011] Preferably, in the front and middle regions of the blade, the thickness of the blade is asymmetrically distributed on both sides of the bone surface.

[0012] Preferably, the direction from the leading edge to the trailing edge of the blade includes a first thickness region, a second thickness region and a third thickness region arranged in sequence, and the thickness of the blade in the first thickness region gradually decreases along its own extension direction; in the second thickness region, the distance between the pressure surface of the blade and the bone surface gradually decreases, and the distance between the suction surface of the blade and the bone surface gradually increases; in the third thickness region, the pressure surface and the suction surface of the blade are symmetrically distributed about the bone surface.

[0013] Preferably, the blade has a spatially twisted structure from the leading edge to the trailing edge, and the direction from the leading edge to the trailing edge of the blade includes a first inclination angle region, a second inclination angle region and a third inclination angle region arranged in sequence, the inclination angle of the blade in the first inclination angle region gradually decreases along the extension direction of the blade; the inclination angle of the blade in the second inclination angle region is smaller than the minimum inclination angle in the first inclination angle region; the inclination angle of the blade in the third inclination angle region is smaller than the minimum inclination angle in the second inclination angle region.

[0014] Preferably, the leading edge of the blade has an elliptical cross-section, the major axis direction of the elliptical cross-section is consistent with the extension direction of the blade; the trailing edge of the blade has a cutting structure, the contour line of the cutting structure intersects with the outlet circumference of the impeller to form an arc-shaped transition area.

[0015] Preferably, the cross-sectional shape of the vortex chamber of the volute is an axisymmetric structure, and the cross-sectional shape of the vortex chamber includes a convergent section and an expansion section connected in sequence along the extension direction of the blade; the contour line of the convergent section is a concave curve, the contour line of the expansion section is a convex curve, and the convergent section and the expansion section smoothly transition at the maximum diameter of the vortex chamber section.

[0016] Preferably, a first concave ring structure is provided at the corresponding positions on the inner surface of the front end cover and the front end of the impeller, respectively. The first concave ring structure includes a first concave ring and a second concave ring of different widths. The first concave ring and the second concave ring are axially staggered to form the sealing structure.

[0017] Preferably, a second concave ring structure is provided at the inner surface of the front end cover and the corresponding position of the impeller, and the second concave ring structure includes two third concave rings with the same width. The two third concave rings are arranged opposite to each other in the axial direction, and the open ends of the two third concave rings are buckled together to form a cavity. A sealing filler is provided in the cavity to constitute the sealing structure.

[0018] Beneficial effects of the present invention:

[0019] The high-efficiency, wear-resistant centrifugal sand and gravel conveying pump proposed by the present invention has a smoothly transitioned flow channel formed on the impeller axial surface, which prevents sudden cross-sectional changes or sharp turns in the fluid flow from the inlet to the outlet, reduces the risk of large-sized solid particles colliding and being retained in the flow channel, and ensures smooth passage of particles with the fluid. The multiple blades spaced apart on the impeller use a skeleton composed of multiple continuous spline curves. This combination of continuous and smooth curves creates a natural transition in the blade surface contour, eliminating the local flow separation areas produced by traditional straight-line spliced ​​blades, thereby reducing the adhesion and accumulation of particles on the blade surface. The blade installation angle is set with at least one inflection point along the skeleton arc length variation curve, so that the blade angle distribution follows a variation pattern of first increasing and then decreasing, or first decreasing and then increasing. This non-monotonic angle variation can actively adjust the force exerted by the fluid on the particles at different blade heights. By increasing the installation angle in the impeller inlet area, the ability to capture solid particles is improved, which helps to adjust the flow direction of large particles and further improve the pumping effect. The front cover is located at the volute inlet, and the seal formed between it and the inner surface of the volute prevents slurry leakage, ensuring the normal operation of the pump. It also prevents the ingress of external impurities, ensuring the smooth flow of the internal flow path and preventing blockage caused by impurities. In summary, the unique flow path and blade design of the impeller, as well as the sealing structure between the front cover and the volute, effectively improve the pumping efficiency of large particles in the slurry, reduce the risk of blockage, and better adapt to the needs of efficient delivery in complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a cross-sectional view of a high-efficiency, wear-resistant centrifugal sand and gravel conveying pump provided in Example 1 of the present invention;

[0021] Figure 2 1 is a schematic structural diagram of a volute provided in Embodiment 1 of the present invention;

[0022] Figure 3 This is a first structural schematic diagram of a blade provided in Example 1 of the present invention;

[0023] Figure 4 This is a second structural schematic diagram of the blade provided in the first embodiment of the present invention;

[0024] Figure 5 is a cross-sectional view of a sealing structure provided in Example 1 of the present invention;

[0025] Figure 6 It is a cross-sectional view of the sealing structure provided in the second embodiment of the present invention.

[0026] In the picture:

[0027] 1. Volute; 2. Front cover; 3. Rear cover; 4. Impeller; 5. Blades; 100. First concave ring structure; 101. First concave ring; 102. Second concave ring; 200. Second concave ring structure; 201. Third concave ring; 202. Sealing filler. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but are not to be construed as limiting the present invention.

[0029] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0030] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0032] Example 1

[0033] See also Figures 1 to 5 The embodiment of the present invention provides a high-efficiency, wear-resistant centrifugal sand and gravel conveying pump comprising a volute 1, a front cover 2, a rear cover 3, and an impeller 4. The impeller 4 is disposed within the volute 1, and the axial surface of the impeller 4 forms a smoothly transitioned flow channel. A plurality of blades 5 are spaced apart along the upper edge of the impeller 4 around its own axis. The rib surface of the blade 5 is composed of a plurality of continuous spline curves along its own extension direction, and the installation angle of the blade 5 has at least one inflection point along the arc length variation curve of the rib surface. The front cover 2 is disposed at the inlet of the volute 1, and a sealing structure is formed between the inner surface of the front cover 2 and the volute 1.

[0034] The high-efficiency, wear-resistant centrifugal sand and gravel pump proposed in this invention features a smoothly transitioned flow path formed on the axial surface of the impeller 4. This prevents sudden cross-sectional changes or sharp turns in the fluid flow from inlet to outlet, reduces the risk of large solid particles colliding and being trapped in the flow path, and ensures smooth passage of particles along with the fluid. The multiple blades 5 spaced apart on the impeller 4 utilize a skeleton composed of multiple continuous spline curves. This continuous, smooth curve combination creates a natural transition in the surface profile of the blades 5, eliminating the localized flow separation zones produced by traditional straight-line spliced ​​blades 5 and reducing particle adhesion and accumulation on the blade 5 surface. The blade 5 mounting angle is configured with at least one inflection point along the arc length variation curve of the skeleton, resulting in an angular distribution that either increases first and then decreases, or decreases first and then increases. This non-monotonic angle variation actively regulates the force exerted by the fluid on particles at different blade heights. Increasing the mounting angle at the impeller 4 inlet improves solid particle capture, helps adjust the flow direction of large particles, and further enhances pumping efficiency. Front cover 2 is positioned at the inlet of volute 1. The seal formed between it and the inner surface of volute 1 prevents slurry leakage, ensuring the proper operation of the pump. It also prevents the ingress of external impurities, ensuring a smooth internal flow path and preventing blockages caused by these impurities. In summary, through the unique flow path and blade design of impeller 4, as well as the seal between front cover 2 and volute 1, this delivery pump effectively improves the pumping efficiency of large particles in the slurry, reduces the risk of blockage, and better adapts to the needs of efficient delivery under complex working conditions.

[0035] The specific structure and working principle of the delivery pump are described in detail below.

[0036] The impeller 4 is arranged in the volute 1, and the axial surface of the impeller 4 forms a flow channel with a smooth transition. The axial surface refers to a specific plane containing the rotation axis of the impeller 4. On the specific plane containing the rotation axis, the contour line of the flow channel (usually surrounded by the hub, blades 5 and cover plate) inside the impeller 4 for the fluid (such as slurry) to pass through is smooth and continuous, without sudden turns or steps. This smooth transition is crucial for guiding the smooth flow of the fluid, reducing flow separation and energy loss, and especially preventing large particles of solid from getting stuck or deposited at the corners of the flow channel. It ensures the natural smoothness of the flow path of the fluid from the inlet to the outlet of the impeller 4.

[0037] Specifically, the width of the impeller 4 flow channel is smallest at the outlet, at 42% of the suction port diameter. The maximum curvature of the axial surface on the front end cover 2 is located behind the leading edge of the blade 5, at approximately 53% of the axial length. The product of the maximum curvature and the axial velocity at the rated flow rate is approximately 28.6s-1 (in this embodiment, the curvature of the front end cover 2 is 4.4m-1, and the axial velocity in the vicinity is 6.5m / s). The maximum curvature of the axial surface on the rear end cover 3 is located near the leading edge of the blade 5, at approximately 48% of the axial length. The product of the maximum curvature and the axial velocity at the rated flow rate is approximately 11.4s-1 (in this embodiment, the curvature of the rear end cover 3 is 2.2m-1, and the axial velocity in the vicinity is 5.2m / s). Through the above-mentioned arrangement, sufficient curvature is provided for the axial flow of the delivery pump to turn from the horizontal direction to the vertical direction, reducing secondary flow on the axial surface, and enabling the delivery pump to maintain high efficiency within a wide range of flow variation.

[0038] A plurality of blades 5 are arranged at intervals around the impeller 4's axis. Specifically, there are three blades 5, and the angle between each two adjacent blades 5 is 120 degrees. This layout makes the impeller 4 exert a more uniform force on the slurry when it rotates. In the circumferential direction, the blades 5 are evenly spaced and can work together to allow large particles in the slurry to flow more orderly, reducing the possibility of collision and accumulation between particles, thereby further reducing the chance of blockage. Moreover, this evenly distributed layout of blades 5 can optimize the force balance during the rotation of the impeller 4, making the delivery pump more stable during operation and reducing equipment vibration caused by uneven force. This not only extends the service life of the equipment, but also ensures that the delivery pump continues to pump the slurry efficiently, improving its working reliability under complex working conditions.

[0039] The bone surface of the blade 5 is composed of multiple continuous spline curves along its own extension direction, and there is at least one inflection point in the arc length change curve of the installation angle of the blade 5 along the bone surface. Specifically, the bone surface is composed of three continuous spline curves along its own extension direction, namely the first spline curve, the second spline curve and the third spline curve. The first spline curve is located on the side of the blade 5 close to the rear end cover 3. The inlet installation angle of the first spline curve is 38° to 40°, the outlet installation angle is 14° to 16°, and the wrap angle is 148° to 152°; the second spline curve is located in the middle position of the blade 5. The inlet installation angle of the second spline curve is 25° to 27°, the outlet installation angle is 14° to 16°, and the wrap angle is 149° to 153°; the third spline curve is located on the side of the blade 5 close to the front end cover 2; the inlet installation angle of the third spline curve is 16° to 18°, the outlet installation angle is 14° to 16°, and the wrap angle is 150° to 154°. Through the above-mentioned setting, the function curve of the installation angle of the blade 5 with respect to the arc length of the blade 5 is not monotonic and the convexity and concavity are not single, which is different from the traditional high-efficiency conveying pump (the first-order derivative and second-order derivative curves of the arc length-installation angle function of the traditional blade 5 with respect to the arc length are on one side of the 0 value, and the first-order derivative and second-order derivative curves of the pump installation angle function with respect to the arc length both cross the 0 value). The blade 5 is convex at first and then concave, which comprehensively balances the passability, efficiency and anti-wear and anti-cavitation characteristics of the sand and gravel conveying pump, thereby providing efficient and stable performance under the working conditions of conveying high-concentration and large-particle-size solid particles.

[0040] In the front and middle regions of blade 5, the thickness of blade 5 is asymmetrically distributed on either side of the slab surface. In the front, this asymmetrical thickness distribution guides large particles in the incoming slurry in a specific direction, optimizing the flow field at the inlet and allowing particles to enter the flow channel more smoothly. This reduces impact and turbulence, lowers energy loss, and improves pump efficiency. In the middle region, the asymmetrical thickness of blade 5 coordinates the movement of particles in the flow channel, further adjusting their trajectory, preventing particle aggregation or collision in this area and reducing the risk of blockage.

[0041] Specifically, the direction from the leading edge to the trailing edge of the blade 5 includes a first thickness region, a second thickness region and a third thickness region arranged in sequence. In the first thickness region, the thickness of the blade 5 gradually decreases along its own extension direction; in the second thickness region, the distance between the pressure surface and the bone surface of the blade 5 gradually decreases, and the distance between the suction surface and the bone surface of the blade 5 gradually increases; in the third thickness region, the pressure surface and the suction surface of the blade 5 are symmetrically distributed about the bone surface.

[0042] In this embodiment, the front region of the blade 5 is thicker overall. The first thickness region is from the leading edge of the blade 5 to approximately 15% of the blade 5 arc length. Within the first thickness region, the blade 5 gradually narrows, and then the distance from the pressure side of the blade 5 to the bone surface decreases, while the thickness from the suction side of the blade 5 to the bone surface increases. The second thickness region is approximately 40% of the blade 5 arc length. In the second thickness region, the blade 5 has the smallest thickness and the greatest asymmetry. The asymmetry then gradually decreases to the third thickness region after 60% of the blade 5 arc length. In the third thickness region, the blade 5 reaches and maintains its maximum thickness, and the thickness asymmetry disappears. Unlike conventional pumps where the blade 5 has uniform thickness or gradually increases from the inlet to the outlet, this design improves the load distribution on the blade 5, reduces flow separation on the surface of the blade 5, and improves wear resistance and cavitation resistance. It also takes into account both the efficiency and flow performance of the hydraulic pump.

[0043] The blade 5 presents a spatially twisted structure from the leading edge to the trailing edge. The direction from the leading edge to the trailing edge of the blade 5 includes a first inclination angle region, a second inclination angle region and a third inclination angle region arranged in sequence. The inclination angle of the blade 5 in the first inclination angle region gradually decreases along the extension direction of the blade 5; the inclination angle of the blade 5 in the second inclination angle region is smaller than the minimum inclination angle in the first inclination angle region; the inclination angle of the blade 5 in the third inclination angle region is smaller than the minimum inclination angle in the second inclination angle region.

[0044] In this embodiment, the inclination angle of the first inclination area is 30° to 50°, the inclination angle of the second inclination area is 10° to 20°, and the inclination angle of the third inclination area is close to 0° to 5°, thereby suppressing the local backflow at the outlet of the impeller 4 at different axial widths and circumferential angles, and ensuring that the mud flows evenly into the volute 1.

[0045] The leading edge of blade 5 has an elliptical cross-section, with the major axis of the elliptical cross-section aligning with the extension direction of blade 5. This alignment creates a smooth, streamlined flow-guiding surface at the leading edge of blade 5. This structure guides large solid particles along their major axis when they contact the leading edge of blade 5, preventing the particles from momentarily impacting and rebounding due to right-angled edges. Furthermore, the continuous curvature of the ellipse disperses particle impact stress, reducing the local wear rate at the leading edge and the probability of particles rebounding toward the center of the flow channel after impact, ensuring that the particle group enters the flow channel of impeller 4 in an orderly manner.

[0046] The trailing edge of blade 5 features a cutting structure. Its contour intersects with the impeller 4 outlet circumference to create an arc-shaped transition zone, eliminating the flow separation vortex generated by conventional right-angled trailing edges. This arc-shaped transition zone, formed by the intersection of the cutting structure's contour and the impeller 4 outlet circumference, allows the fluid to naturally separate tangentially at the blade 5 outlet, preventing high-speed particles from being retained and swirling due to the abrupt expansion of the trailing edge, ensuring efficient, one-time discharge of solid particles from the flow channel.

[0047] The cross-sectional shape of the vortex chamber of the volute 1 is an axisymmetric structure. The cross-sectional shape of the vortex chamber includes a convergent section and an expansion section connected in sequence along the extension direction of the blade 5. The contour line of the convergent section is a concave curve, which can gather and accelerate the fluid entering the volute 1, make the fluid velocity distribution more reasonable, and enhance the carrying capacity of large particles. The contour line of the expansion section is a convex curve, which can allow the accelerated fluid to diffuse smoothly, reduce the flow rate, effectively convert kinetic energy into pressure energy, and increase the pump head. In addition, the convergent section and the expansion section smoothly transition at the maximum diameter of the vortex chamber section, ensuring the continuity of the fluid flow in the volute 1, reducing the impact and turbulence caused by sudden changes in the flow channel, further improving the delivery efficiency and stability of the delivery pump for slurry containing large particles, and reducing the risk of blockage.

[0048] Specifically, the cross-sectional shape of the vortex chamber of the volute 1 is pear-shaped, and the vortex chamber selects 8 sections that are 45 degrees to each other. The ratio of the end cross-sectional area of ​​the volute 1 to the starting cross-sectional area is 2.2 (the end cross-sectional area of ​​the volute 1 is the cross-sectional area where the liquid is about to leave the volute 1 and enter the outlet pipe after completing the energy conversion and flow path in the volute 1, and the starting cross-sectional area of ​​the volute 1 refers to the cross-sectional area where the liquid has just entered the volute 1), and the ratio of the pump suction port diameter to the volute 1 discharge port diameter is 2.8. The area growth rate of the flow cross-section is smaller at first and then larger. This design takes into account the anti-wear effect of the volute 1 and the hydraulic efficiency within a wider flow variation range, while ensuring better tongue passing performance.

[0049] The optimal discharge angle of the volute 1 to the ground is 80°. On the one hand, this design distributes the fluid impact force and the overall gravity of the pump casing on both sides of the pump centerline to optimize the force on the base of the volute 1. On the other hand, it makes the time-averaged value of the cyclic stress on the pump shaft under conditions greater than the rated flow rate point vertically upward along the center of the pump (in the opposite direction to the collinear gravity of the impeller 4 on the pump shaft), which reduces the amplitude of the force on the pump shaft during operation to a certain extent, weakens the vibration of the pump shaft, and improves the working stability and service life of the pump.

[0050] A first concave ring structure 100 is provided on the inner surface of the front end cover 2 at positions corresponding to the front end of the impeller 4. This structure comprises a first concave ring 101 and a second concave ring 102 of varying widths. The first and second concave rings 101 and 102 are axially offset and cooperate to form a sealing structure. The varying widths and axially offset cooperation create a multi-pass labyrinthine seal, which increases the length and difficulty of slurry leakage. For slurry to leak, it must pass through a circuitous path. During this process, the slurry pressure is gradually dispersed, reducing the likelihood of leakage.

[0051] Example 2

[0052] Figure 6A second embodiment is shown, wherein components identical or corresponding to those in the first embodiment are denoted by the corresponding reference numerals. For simplicity, only the differences between the second embodiment and the first embodiment will be described. The difference lies in the presence of a second concave ring structure 200, located on the inner surface of the front cover 2 and corresponding to the impeller 4. The second concave ring structure 200 comprises two third concave rings 201 of equal width, axially opposed to each other. The open ends of the two third concave rings 201 interlock with each other to form a cavity, within which a sealing filler 202 is located, forming a sealing structure. The cavity formed by the two interlocking third concave rings 201 provides a stable installation space for the sealing filler 202, enabling it to better perform its sealing function. Furthermore, the sealing filler 202 filling the cavity further enhances the sealing effect, effectively preventing slurry leakage. Since the slurry contains solid particles, this sealing structure prevents particles from entering key parts of the pump, avoiding wear and damage caused by such particles and extending the service life of the pump. In addition, this sealing structure can maintain stable internal pressure of the pump, ensure efficient operation of the delivery pump, improve the pumping effect of slurry containing large particles, and adapt to complex mining working conditions.

[0053] The above embodiments merely illustrate the basic principles and features of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency, wear-resistant centrifugal sand and gravel conveying pump, comprising a volute (1), a front cover (2), a rear cover (3) and an impeller (4), characterized in that: The impeller (4) is arranged in the volute (1), the axial surface of the impeller (4) forms a smoothly transitioned flow channel, a plurality of blades (5) are arranged on the upper edge of the impeller (4) at intervals around its own axis, the bone surface of the blade (5) is composed of a plurality of continuous spline curves along its own extension direction, and the installation angle of the blade (5) has at least one inflection point along the arc length change curve of the bone surface; The front end cover (2) is arranged at the inlet of the volute (1), and a sealing structure is formed between the inner surface of the front end cover (2) and the volute (1).

2. The high-efficiency and wear-resistant centrifugal sand and gravel conveying pump according to claim 1 is characterized in that: The bone surface is composed of three continuous spline curves along its own extension direction, namely a first spline curve, a second spline curve and a third spline curve. The first spline curve is located on the side of the blade (5) close to the rear end cover (3), the inlet installation angle of the first spline curve is 38° to 40°, the outlet installation angle is 14° to 16°, and the wrap angle is 148° to 152°; the second spline curve is located in the middle position of the blade (5), the inlet installation angle of the second spline curve is 25° to 27°, the outlet installation angle is 14° to 16°, and the wrap angle is 149° to 153°; the third spline curve is located on the side of the blade (5) close to the front end cover (2); the inlet installation angle of the third spline curve is 16° to 18°, the outlet installation angle is 14° to 16°, and the wrap angle is 150° to 154°.

3. The high-efficiency and wear-resistant centrifugal sand and gravel conveying pump according to claim 1 is characterized in that: Three blades (5) are provided, and the angle between each two adjacent blades (5) is 120 degrees.

4. The high-efficiency and wear-resistant centrifugal sand and gravel conveying pump according to claim 1 is characterized in that: In the front and middle regions of the blade (5), the thickness of the blade (5) is asymmetrically distributed on both sides of the bone surface.

5. The high-efficiency and wear-resistant centrifugal sand and gravel conveying pump according to claim 4 is characterized in that: The blade (5) includes a first thickness region, a second thickness region, and a third thickness region arranged in sequence from the leading edge to the trailing edge. The thickness of the blade (5) in the first thickness region gradually decreases along its own extension direction; the distance between the pressure surface of the blade (5) and the bone surface in the second thickness region gradually decreases, and the distance between the suction surface of the blade (5) and the bone surface gradually increases; and the pressure surface and the suction surface of the blade (5) in the third thickness region are symmetrically distributed with respect to the bone surface.

6. The high-efficiency and wear-resistant centrifugal sand and gravel conveying pump according to claim 1 is characterized in that: The blade (5) presents a spatially twisted structure in the direction from the leading edge to the trailing edge. The blade (5) includes a first inclination angle region, a second inclination angle region, and a third inclination angle region arranged in sequence in the direction from the leading edge to the trailing edge. The inclination angle of the blade (5) in the first inclination angle region gradually decreases along the extension direction of the blade (5); the inclination angle of the blade (5) in the second inclination angle region is smaller than the minimum inclination angle in the first inclination angle region; and the inclination angle of the blade (5) in the third inclination angle region is smaller than the minimum inclination angle in the second inclination angle region.

7. The high-efficiency and wear-resistant centrifugal sand and gravel conveying pump according to claim 1 is characterized in that: The leading edge of the blade (5) has an elliptical cross-section, the major axis direction of the elliptical cross-section is consistent with the extension direction of the blade (5); the trailing edge of the blade (5) has a cutting structure, the contour line of the cutting structure intersects with the outlet circumference of the impeller (4) to form an arc-shaped transition area.

8. The high-efficiency and wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that: The cross-sectional shape of the vortex chamber of the volute (1) is an axisymmetric structure, and the cross-sectional shape of the vortex chamber includes a convergent section and an expansion section connected in sequence along the extension direction of the blade (5); the contour line of the convergent section is an inward concave curve, and the contour line of the expansion section is an outward convex curve, and the convergent section and the expansion section smoothly transition at the maximum diameter of the vortex chamber section.

9. The high-efficiency and wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that: A first concave ring structure (100) is provided at corresponding positions on the inner surface of the front end cover (2) and the front end of the impeller (4), respectively. The first concave ring structure (100) comprises a first concave ring (101) and a second concave ring (102) of different widths. The first concave ring (101) and the second concave ring (102) are staggered in the axial direction to form the sealing structure.

10. The high-efficiency and wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that: A second concave ring structure (200) is provided at positions corresponding to the inner surface of the front end cover (2) and the impeller (4), respectively. The second concave ring structure (200) includes two third concave rings (201) of the same width. The two third concave rings (201) are arranged opposite to each other along the axial direction. The open ends of the two third concave rings (201) are buckled together to form a cavity. A sealing filler (202) is provided in the cavity to form the sealing structure.

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