A centrifugal impeller

Abstract

The utility model relates to a centrifugal impeller, including upper end disc, lower end disc and a plurality of long blades, the central place of lower end disc is provided with the use assembly unit, the assembly unit is provided with the shaft hole, the assembly unit includes upper end and lower end, long blade is arc and surrounds the upper end part setting, upper end disc is provided with the water inlet part, the central place of water inlet part is provided with the water inlet, the inner diameter of water inlet is greater than the diameter of upper end, long blade includes connecting part and the extension from the connecting part to the upper end part periphery from top to bottom, the side of extension is arc and sets up and with the side of connecting part smooth transition, the upper end surface of extension is inclined and sets up and the same as long blade arc rotation direction with the inclined direction, the short blade that is arc is provided between adjacent long blades, short blade sets up in connecting part one end close to extension. Through adopting above technical scheme, reduce the necessary net positive suction head of pump, promote the anticavitation performance, effectively divide the runner, restrain the bad vortex and secondary flow, reduce the flow loss.

Description

Technical Field

[0001] This utility model belongs to the field of motorcycle technology, and in particular relates to a centrifugal impeller. Background Technology

[0002] The water-cooling system of a motorcycle is crucial for its efficient and stable operation. The cooling pump, consisting of a pump casing, impeller, and water seal, is a centrifugal water pump. The impeller, located inside the cooling pump casing, pumps water through radially long blades mounted on a valve disc. Cooling water flows in from the center and, under the centrifugal force of the rotating impeller, is pumped out to the drain. During the operation of the circulating water pump, cavitation is a significant factor affecting the pump's outlet flow rate and head. Cavitation is a physical characteristic of water and vapor changes. During normal operation of the centrifugal water pump, the liquid pressure decreases from the pump inlet to the impeller inlet, reaching its lowest point near the inlet of the long impeller blades. As the impeller rotates, the high-speed rotating impeller performs work on the liquid, increasing its energy and pressure. When the pressure near the inlet of the long impeller blades is lower than the saturated vapor pressure at the liquid's transport temperature, the liquid begins to vaporize and produce bubbles. These bubbles burst as they flow into the high-pressure zone within the pump body, and the surrounding liquid rapidly fills the cavities, creating a hydraulic impact. This phenomenon of bubble formation, development, and bursting is called cavitation. When cavitation occurs in the impeller, the unstable cavitation process will cause the water pump to vibrate and make noise. At the same time, because cavitation causes bubbles to block the impeller channels, the pump's flow rate and head will decrease, and its efficiency will drop. Utility Model Content

[0003] In summary, to overcome the shortcomings of the prior art, this utility model provides a centrifugal impeller.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a centrifugal impeller, comprising an upper end plate, a lower end plate, and a plurality of long blades connecting the upper and lower end plates together. The lower end plate has an assembly portion at its center for connection to a drive shaft. The assembly portion has a through-hole for mounting the impeller on the drive shaft. The assembly portion includes an upper end portion on one side of the lower end plate corresponding to the long blades and a lower end portion on the other side of the lower end plate. The long blades are arc-shaped and surround the upper end portion. The upper end plate has a water inlet portion at its center on the other side of the long blades, and a water inlet is located at the center of the water inlet portion. The inner diameter of the sprue is larger than the diameter of the upper end. The long blade includes a connecting part that connects the upper end plate and the lower end plate, and an extension part that extends from the connecting part to the outer periphery of the upper end plate from top to bottom. The height of one end of the extension part relative to the connecting part is higher than the distance between the upper end plate and the lower end plate. The height of one end of the extension part relative to the upper end plate is lower than the upper end surface of the upper end plate. The side of the extension part is arc-shaped and smoothly transitions with the side of the connecting part. The upper end surface of the extension part is inclined and the inclination direction is the same as the arc rotation direction of the long blade. An arc-shaped short blade is provided between adjacent long blades. The short blade is provided at the end of the connecting part near the extension part.

[0005] By adopting the above technical solution, the extended section performs work on the fluid earlier, increasing the fluid pressure sooner. This helps reduce the pump's required net positive suction head (NPSH) and improves its cavitation resistance. The inclined direction of the upper end face is the same as the blade rotation direction, providing a smooth "guide ramp" for the fluid. This greatly reduces the impact loss caused by the fluid hitting the blades, allowing the fluid to enter the flow channel more smoothly and further improving efficiency. The inner diameter of the inlet is larger than the diameter of the upper end of the assembly section, forming a smooth, tapering channel that reduces the flow velocity of the coolant when entering the impeller, thereby increasing the pressure at the inlet. This design reduces the probability of cavitation; the curved sides of the long blades and the smooth transitions at the joints prevent sudden flow changes, minimizing flow separation and eddy current generation, reducing unnecessary energy loss, and thus improving efficiency; the design of setting short blades between adjacent long blades, with the short blades originating in the critical area where eddies and secondary flows begin to generate and develop in the flow channel, effectively divides the flow channel, suppresses the generation of undesirable eddies and secondary flows, reduces flow losses, and thus improves pump efficiency. At the same time, increasing the number of short blades is equivalent to increasing the number of blades that do work, which helps to increase the pump's head and flow rate.

[0006] The present invention further comprises: an inner end, an outer end, a front arc surface, a back arc surface, an upper end surface, and a lower end surface; the inner end of the short blade is located in the middle of an adjacent long blade; the short blade is offset toward the working surface from the inner end to the outer end; both the front arc surface and the back arc surface are inclined in the direction of rotation; and the width of the upper end surface is smaller than the width of the lower end surface.

[0007] By adopting the above technical solution, the inner end of the short blade is located in the middle of the adjacent long blade. The short blade is offset from the inner end to the outer end towards the working surface (the front of the long blade), which effectively improves the flow state inside the impeller, helps to suppress secondary flow caused by centrifugal force, and prevents low-energy fluid from accumulating on the back (suction surface) of the long blade to form a wake region. This makes the flow at the impeller outlet more uniform, reduces hydraulic losses, and improves the pump's efficiency and operational stability. Both the front arc surface (working surface) and the back arc surface (suction surface) of the short blade are inclined towards the impeller rotation direction. This design can significantly improve the fluid inlet conditions. The curved surface better "caters" to the direction of fluid entry, allowing the fluid to enter the flow channel more smoothly and reducing impact losses caused by improper angles. At the same time, it ensures the continuity and smoothness of the flow from the inlet to the inside of the flow channel, which helps to reduce flow separation and the generation of eddies, thereby reducing hydraulic losses and improving pump efficiency. The width of the upper end face is smaller than that of the lower end face, providing a larger root connection area and structural strength, which can better resist the huge centrifugal force generated during high-speed rotation, improve the mechanical reliability and life of the impeller, and achieve a perfect transition from the high efficiency of the fluid at the inlet to the structural robustness at the root.

[0008] The present invention further provides that the inclination angle of the front arc surface is 1°-4° and the inclination angle of the back arc surface is 15°-30°.

[0009] By adopting the above technical solution, the front arc surface serves as the working surface, and the extremely small inclination angle of 1°-4° makes the leading edge of the short blades very gentle. This allows the fluid (coolant) to enter the working area of ​​the short blades with almost no impact and low disturbance, greatly reducing the hydraulic impact loss at the inlet. The reduction in inlet impact also means a lower relative flow velocity in the inlet area, which helps to increase local pressure, reduce the pump's required net positive suction head (NPSH), and improve cavitation resistance. The back arc surface serves as the suction surface, and the inclination angle of 15°-30° provides significant guidance and sufficient curvature for the fluid. The short blades can effectively guide the fluid to smoothly turn and merge into the main flow channel, avoiding... Flow separation and vortex generation reduce hydraulic losses within the flow channel. The larger inclination angle allows the short blades to efficiently output energy, thereby increasing the head. The forward arc surface is responsible for introducing fluid with low loss, while the back arc surface is responsible for efficiently discharging and guiding the fluid. This synergistic work allows the short blades to more effectively divide the flow channel, suppressing secondary flows and wakes between long blades, resulting in a more uniform distribution of velocity and pressure inside the impeller, thus significantly improving pump efficiency. Optimized flow means less pressure pulsation and vortex shedding, which helps reduce vibration and noise, making the pump run more smoothly. At the same time, smooth flow also reduces the pulsating impact of fluid on the blades, which is beneficial for extending service life.

[0010] The present invention further features that the inner end portion is arc-shaped.

[0011] By adopting the above technical solutions, the arc shape provides a smooth and gradual flow channel for the fluid, which can greatly reduce flow separation and eddy current generation, significantly reduce hydraulic losses, and improve pump efficiency; the optimized inlet shape helps the fluid enter the impeller more smoothly, reduces the inlet velocity, and improves cavitation resistance; the arc transition eliminates sharp right angles, makes the stress distribution more uniform, avoids high stress areas, enhances structural rigidity, and greatly improves the service life of short blades.

[0012] The present invention further comprises: the diameter of the lower end plate is D1, the diameter of the inner end is d1, 0.6D1≤d1≤0.7D1, and the diameter of the outer end is d2, 0.75D1≤d2≤0.85D1.

[0013] By adopting the above technical solutions, early intervention in the root region of the flow channel, where secondary flow and vortices are most likely to be generated and developed, effectively constrains and divides vortices, reducing flow losses; early intervention and a relatively large inlet area help reduce the relative flow velocity at the inlet, thereby increasing local pressure and delaying cavitation; a large outlet diameter ensures that the splitting blades can effectively share the head and work in coordination with the long blades to ensure that the design head and efficiency are achieved, optimizing the outlet flow, reducing impact losses, and improving stability and efficiency.

[0014] The present invention further specifies that the distance between the upper and lower end plates is h1, and the height of the short blade is h2, wherein 0.4h1≤h2≤0.6h1.

[0015] By adopting the above technical solution, in a centrifugal impeller, the root of the flow channel between two long blades is the region where secondary flow and vortices are most likely to be generated and developed. Setting the height of the short blades to 0.4h1≤h2≤0.6h1 can effectively penetrate into this region to divide and constrain vortices, preventing their development and growth, thereby significantly reducing flow losses and improving the hydraulic efficiency of the pump. The short blades of moderate height can effectively share part of the head and work in conjunction with the long blades to increase flow rate and head. When rotating at high speed, the blades bear huge centrifugal forces. The greater the height of the short blades, the greater their own mass and the greater the centrifugal force they bear, and the higher the requirements for the root strength. Limiting h2 to within 0.6h1 can prevent the blades from being too tall, thereby controlling the centrifugal force and improving the structural reliability and service life of the blades.

[0016] The present invention is further configured such that: the number of long blades is 5, and the inner end of the long blade and the outer end of the adjacent long blade are arranged in a straight line through the center of the lower end plate.

[0017] By adopting the above technical solution, the centrifugal force generated during high-speed rotation cancels each other out in all directions, making the impeller itself close to a perfect dynamic balance state, minimizing vibration and noise; the symmetrical layout allows the huge centrifugal force generated during high-speed rotation to be evenly transmitted to the impeller hub and shaft seat, avoiding local stress concentration and improving the structural strength and service life of the impeller.

[0018] The present invention further comprises: the upper end plate is conical; the connection between the lower end of the water inlet and the upper end plate is an arc surface; the upper end surface of the upper end is higher than the lowest end of the upper end plate; the distance between the upper end of the water inlet and the lower end plate is H1; the height of the upper end is H2; the height of the highest end of the connecting part is H3; the height of the highest end of the extension part is H4; 0.4H1≤H2≤0.45H1; 0.45H1≤H3≤0.5H1; 0.7H1≤H4≤0.75H1.

[0019] By adopting the above technical solution, the seamless connection between the conical upper end plate and the arc-shaped inlet provides the coolant with an ultra-low resistance flow channel from axial intake to radial ejection, greatly reducing unnecessary turbulence and energy loss; 0.4H1≤H2≤0.45H1 determines the cross-sectional area of ​​the inlet flow channel, ensuring a sufficiently large inlet flow area, resulting in a reduced inlet velocity, increased static pressure at the inlet, reduced possibility of fluid vaporization, and thus delayed cavitation; 0.45H1≤H3≤0.5H1 provides a natural and smooth "downhill" path, allowing the fluid to flow more smoothly into the impeller under pressure energy, effectively avoiding cavitation caused by sharp turns or sudden height changes. The generated eddies and flow separation reduce the inlet velocity, increase static pressure, and make the coolant more difficult to vaporize, thus improving cavitation resistance. The extension helps optimize the velocity and pressure distribution in the inlet area, increases local static pressure, improves the pump's cavitation resistance, protects the impeller, and suppresses the generation and development of undesirable eddies, allowing the fluid to flow more smoothly and stably to the outlet, thereby reducing hydraulic losses and improving the pump's hydraulic efficiency. The blades bear huge centrifugal forces when rotating at high speeds (0.7H1≤H4≤0.75H1), which helps to form a better stress distribution and avoid excessive centrifugal stress concentration at the blade root or other critical parts, thereby improving the fatigue strength of the blades and the reliability of long-term operation.

[0020] The present invention further includes an oil storage tank arranged around the outer periphery of the lower end plate corresponding to the lower end.

[0021] By adopting the above technical solution, the oil reservoir can store a certain amount of lubricating oil or grease. When the bearing is running, the lubricating oil can be continuously and evenly supplied to the rolling elements and raceways of the bearing to form an oil film, which greatly reduces direct dry friction between metals, thereby reducing wear and extending the service life of the bearing and related components.

[0022] The specific embodiments of this utility model are described below with reference to the accompanying drawings and examples. Attached Figure Description

[0023] Figure 1 This is a perspective view of an embodiment of the present utility model.

[0024] Figure 2 This is a side sectional view of an embodiment of the present utility model.

[0025] Figure 3 This is a top sectional view of an embodiment of the present utility model.

[0026] Reference numerals: 1. Upper end plate, 11. Water inlet, 12. Water inlet, 2. Lower end plate, 21. Assembly part, 211. Upper end, 212. Lower end, 22. Shaft hole, 23. Oil reservoir, 3. Long blade, 31. Connecting part, 32. Extension part, 4. Short blade, 41. Inner end, 42. Outer end, 43. Front arc surface, 44. Back arc surface, 45. Upper end surface, 46. Lower end surface. Detailed Implementation

[0027] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

[0028] See appendix Figure 1-3This embodiment discloses a centrifugal impeller, including an upper end plate 1, a lower end plate 2, and a plurality of long blades 3 connecting the upper end plate 1 and the lower end plate 2 together. The lower end plate 2 has an assembly part 21 at its center for connection with a drive shaft. The assembly part 21 has a through-hole 22 for mounting the impeller on the drive shaft. The assembly part 21 includes an upper end portion 211 on one side of the lower end plate 2 corresponding to the long blades 3 and a lower end portion 212 on the other side of the lower end plate 2. The long blades 3 are arc-shaped and surround the upper end portion 211. The upper end plate 1 has a water inlet 11 at its center on the other side of the long blades 3, and a water inlet 12 at its center. The inner diameter of the water inlet 12 is larger than that of the upper end portion 211. The long blade 3 has a diameter of 211. It includes a connecting part 31 that connects the upper end plate 1 and the lower end plate 2, and an extension part 32 that extends from the connecting part 31 to the outer periphery of the upper end plate 211 from top to bottom. The height of one end of the extension part 32 relative to the connecting part 31 is higher than the distance between the upper end plate 1 and the lower end plate 2. The height of one end of the extension part 32 relative to the upper end plate 211 is lower than the upper end surface of the upper end plate 211. The side of the extension part 32 is arc-shaped and smoothly transitions with the side of the connecting part 31. The upper end surface of the extension part 32 is inclined and the inclination direction is the same as the arc rotation direction of the long blade 3. An arc-shaped short blade 4 is provided between adjacent long blades 3. The short blade 4 is provided at the end of the connecting part 31 near the extension part 32.

[0029] This embodiment further specifies that the short blade 4 includes an inner end 41, an outer end 42, a front arc surface 43, a back arc surface 44, an upper end surface 45, and a lower end surface 46. The inner end 41 of the short blade 4 is located in the middle of an adjacent long blade 3. The short blade 4 is offset towards the working surface from the inner end 41 to the outer end 42. The front arc surface 43 and the back arc surface 44 are both inclined in the direction of rotation. The width of the upper end surface 45 is smaller than the width of the lower end surface 46.

[0030] In this embodiment, the inclination angle of the front arc surface 43 is 1°-4°, and the inclination angle of the back arc surface 44 is 15°-30°.

[0031] In this embodiment, the inner end portion 41 is further configured in an arc shape.

[0032] In this embodiment, the diameter of the lower end plate 2 is D1, the diameter of the inner end 41 is d1, 0.6D1≤d1≤0.7D1, and the diameter of the outer end 42 is d2, 0.75D1≤d2≤0.85D1.

[0033] In this embodiment, the distance between the upper disk 1 and the lower disk 2 is h1, and the height of the short blade 4 is h2, where 0.4h1≤h2≤0.6h1.

[0034] In this embodiment, the number of long blades 3 is 5, and the inner end of the long blade 3 and the outer end of the adjacent long blade 3 are arranged in a straight line through the center of the lower end plate 2.

[0035] This embodiment further specifies that: the upper plate 1 is conical; the connection between the lower end of the water inlet 12 and the upper plate 1 is an arc surface; the upper surface of the upper part 211 is higher than the lowest end of the upper plate 1; the distance between the upper end of the water inlet 11 and the lower plate 2 is H1; the height of the upper part 211 is H2; the height of the highest point of the connecting part 31 is H3; the height of the highest point of the extension part 32 is H4; 0.4H1≤H2≤0.45H1; 0.45H1≤H3≤0.5H1; 0.7H1≤H4≤0.75H1.

[0036] In this embodiment, an oil storage tank 23 is further provided around the outer periphery of the lower end plate 2 corresponding to the lower end portion 212.

[0037] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "back", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. The term "between" mentioned above does not only refer to the orientation or position, but also includes the interaction between different parts.

[0038] Although this document frequently uses terms such as upper plate 1, water inlet 11, water inlet 12, lower plate 2, assembly part 21, upper end part 211, lower end part 212, shaft hole 22, oil reservoir 23, long blade 3, connecting part 31, extension part 32, short blade 4, inner end part 41, outer end part 42, front arc surface 43, back arc surface 44, upper end surface 45, and lower end surface 46, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any kind of additional limitation would contradict the spirit of this utility model.

Claims

1. A centrifugal impeller, characterized in that: The device includes an upper end plate, a lower end plate, and several long blades connecting the upper and lower end plates. The lower end plate has an assembly part at its center for connection to a drive shaft. The assembly part has a through-hole for mounting an impeller on the drive shaft. The assembly part includes an upper end portion on one side of the lower end plate corresponding to the long blades and a lower end portion on the other side of the lower end plate. The long blades are arc-shaped and surround the upper end portion. The upper end plate has a water inlet at its center on the other side of the long blades. The water inlet has an inlet port at its center, and the inner diameter of the inlet port is larger than the diameter of the upper end portion. The long blade includes a connecting part that connects the upper end plate and the lower end plate, and an extension part that extends from the connecting part to the outer periphery of the upper end plate from top to bottom. The height of one end of the extension part relative to the connecting part is higher than the distance between the upper end plate and the lower end plate, and the height of one end of the extension part relative to the upper end plate is lower than the upper end surface of the upper end plate. The side of the extension part is arc-shaped and smoothly transitions with the side of the connecting part. The upper end surface of the extension part is inclined and the inclination direction is the same as the arc rotation direction of the long blade. An arc-shaped short blade is provided between adjacent long blades, and the short blade is provided at the end of the connecting part near the extension part.

2. A centrifugal impeller according to claim 1, characterized in that: The short blade includes an inner end, an outer end, a front arc surface, a back arc surface, an upper end surface, and a lower end surface. The inner end of the short blade is located in the middle of an adjacent long blade. The short blade is offset towards the working surface from the inner end to the outer end. Both the front arc surface and the back arc surface are inclined in the direction of rotation. The width of the upper end surface is smaller than the width of the lower end surface.

3. A centrifugal impeller according to claim 2, characterized in that: The inclination angle of the front arc surface is 1°-4°, and the inclination angle of the back arc surface is 15°-30°.

4. A centrifugal impeller according to claim 2, characterized in that: The inner end is arranged in an arc shape.

5. A centrifugal impeller according to claim 2, characterized in that: The diameter of the lower end plate is D1, the diameter of the inner end is d1, 0.6D1≤d1≤0.7D1, and the diameter of the outer end is d2, 0.75D1≤d2≤0.85D1.

6. A centrifugal impeller according to claim 2, characterized in that: The distance between the upper and lower disks is h1, and the height of the short blade is h2, where 0.4h1≤h2≤0.6h1.

7. A centrifugal impeller according to claim 1, characterized in that: The number of long blades is 5, and the inner end of the long blade and the outer end of the adjacent long blade are arranged in a straight line through the center of the lower end plate.

8. A centrifugal impeller according to claim 1, characterized in that: The upper plate is conical in shape, and the connection between the lower end of the water inlet and the upper plate is an arc surface. The upper end surface of the upper part is higher than the lowest end of the upper plate. The distance between the upper end of the water inlet and the lower plate is H1. The height of the upper part is H2. The height of the highest point of the connecting part is H3. The height of the highest point of the extension part is H4. 0.4H1≤H2≤0.45H1, 0.45H1≤H3≤0.5H1, 0.7H1≤H4≤0.75H1.

9. A centrifugal impeller according to claim 1, characterized in that: An oil storage tank is provided around the outer periphery of the lower end plate.

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