Impeller for a liquid pump
Patent Information
- Application Number
- EP2023805558
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-11-25
- Filing Date
- 2023-11-10
- Publication Date
- 2025-10-01
AI Technical Summary
Existing impeller designs for liquid pumps require shaped sonotrodes for ultrasonic welding, leading to high acquisition and manufacturing costs, and expensive laser welding systems, while also lacking efficient liquid distribution and power loss reduction.
The impeller design features a cover plate with integrated pump blades, a base body with a receptacle for an impeller bearing bushing, and a welding process connecting the cover plate to the base body using a force-fitting and material-locking method, allowing for easy manufacturing and reduced costs by using a flat sonotrode or laser-transparent materials, with concave pump blades and rib structures for efficient liquid distribution and power reduction.
This design reduces manufacturing and acquisition costs, enables efficient liquid distribution, and minimizes power losses, resulting in increased efficiency and cost-effectiveness for impeller production and operation.
Smart Images
Figure 1.1
Abstract
Description
[0001] Title: Impeller for a liquid pump
[0002] DESCRIPTION
[0003] The invention relates to an impeller for a liquid pump according to the preamble of claim 1.
[0004] Impellers for liquid pumps are already known. These consist of a baseplate, pump vanes, and a cover plate, which are joined together by welding. In ultrasonic welding, a sonotrode is placed on the impeller in such a way that the direction of vibration acts perpendicularly on the impeller. The disadvantage of this is that, depending on the impeller size, so-called shaped sonotrodes must be used, which incur higher acquisition, setup, and manufacturing costs. In laser welding, a laser beam is applied to the impeller in such a way that the cover plate and baseplate are fused together. The disadvantage of laser welding, however, is that the laser welding system, depending on the design, can be very expensive to purchase.
[0005] The object of the invention is to provide an impeller for a liquid pump in which a sonotrode can be used for ultrasonic welding in such a way that a mold sonotrode is not required for different impeller sizes, the acquisition, setup, and manufacturing costs are low, a component holder can be changed quickly, and the ultrasonic system can be easily coded with an automatic ultrasonic welding program call. Furthermore, an impeller is to be provided that can be easily manufactured and measured in an injection mold and is secured against falling or slipping during transport in an automatic system.
[0006] A further object of the invention is to provide an impeller for a liquid pump in which the impeller can be manufactured cost-effectively by means of laser welding.
[0007] These objects are achieved by the impeller according to the features of claim 1.
[0008] According to the invention, the impeller for a liquid pump has a cover plate and a base body, wherein an intake channel is arranged on the cover plate, wherein a plurality of pump vanes are formed integrally with the cover plate, wherein the base body accommodates a receptacle for an impeller bearing bush in a central region and wherein the cover plate is connected to the base body via at least one pump vane by means of a welding process. The majority of pump vanes extend in the axial direction of the base body. A receptacle for an impeller bearing bush is provided in the central region of the base body. The impeller bearing bush can be mounted in the receptacle before or after the welding process by pressing in, injection molding or other fastening methods known to those skilled in the art.The base body and the cover plate with the plurality of pump vanes are connected to each other by means of welding processes in a force-fitting and / or material-fitting manner.
[0009] In a further development of the invention, the pump vanes have a uniform width at least in sections. This means that the pump vanes have a uniform width over their entire length, i.e., from the root to the tip. However, it is also possible to design the width of the pump vanes from the root to the tip with different widths along the length of the pump vanes. Another possibility would be to design one number of pump vanes with a uniform width and the other number with different widths along the length of the pump vanes.
[0010] A benefit is that the pump vanes extend in a concave curve from the root to the tip of the shroud, i.e., from the intake channel to an edge of the shroud. The concavely curved pump vanes ensure harmonious / even fluid distribution and reduce power losses in the impeller, which in turn leads to increased efficiency.
[0011] According to the invention, at least one axially extending rib structure is formed in sections on at least one pump vane on a side opposite the base body. The axially extending rib structure is formed over a partial length of the pump vanes. Alternatively, however, the axially extending rib structure can also be formed over the entire length of the pump vanes. Formations of several axially extending rib structures arranged side by side on one or more pump vanes over part or the entire length of the pump vanes are also conceivable.
[0012] In a further development of the invention, at least one crown structure extending axially in the direction of the base body is formed on the tip of at least one pump vane. A crown structure is understood to be an axial projection which has a greater axial height and radial width than the axially extending rib structure. The crown structure is formed across the entire width of the pump vanes and at the tip of at least one pump vane. The crown structure can be formed on just one pump vane or on multiple pump vanes. The crown structure at the tip of at least one pump vane serves to center the cover plate in the base body. Alternatively, the crown structure can also correspond to the axial height and radial width of the axially extending rib structure and vice versa. This would mean that the crown structure and the rib structure lie on the same plane.Both alternatives are easy to implement, especially with multiple mold cavities, and therefore also easy to measure. The base body advantageously has a thicker wall thickness in the central area than in the peripheral area. When manufacturing the base body using an injection molding process, the central area of the base body is built up with more material, which is technically feasible. This allows for a mount for a wheel bearing bushing in the central area of the base body.
[0013] It is advantageous that the base body has a plurality of grooves on its front side which correspond to the pump vanes and wherein the base body is flat on its back side.
[0014] According to the invention, the grooves are deeper in the central area than in the edge area. This results from the fact that the grooves are formed parallel to the back of the base body. Also due to the greater wall thickness of the base body in the central area, the grooves are deeper in the central area than in the edge area. Since the pump vanes are all on the same level / height and correspond to the grooves in the base body, the grooves in the central area of the base body are deeper than in the edge area of the base body. The majority of the pump vanes engage in deeper grooves in the central area and thus secure the base body and the cover plate against falling or slipping during transport in an automatic system.
[0015] It is advantageous for the grooves to extend to the edge area of the base body and define recesses in the edge area of the base body. Each groove defines a recess in the edge area of the base body. Alternatively, the grooves may not extend to the edge area of the base body. In this case, the base body would have a closed surface without recesses in the edge area. During impeller manufacture, the crown structure at the tip of at least one pump blade engages the recesses in the edge area of the base body, forming a closed edge area.
[0016] According to the invention, the recesses in the edge region of the base body form a toothed structure. The shape of the toothed structure corresponds to several saw teeth in the edge region of the base body. Due to the correspondence of the pump vanes with the grooves in the base body, the grooves are also concave. The crown structure engages the toothed structure as a counter-contour.
[0017] In a further development, the base body has at least one recess on its rear side in the central region. Because it is manufactured using an injection molding process, the base body has a greater wall thickness than in the edge region. The at least one recess removes material from the rear side of the base body in the central region. During the welding process, the base body is heated and then cools from the edge region to the central region. The at least one recess in the central region enables constant cooling in the edge region and central region after the welding process, because there is less material in the central region due to the at least one recess. This also has the advantage that the base body cannot warp during cooling.
[0018] Alternatively, the base body can have no recesses in the central area on its back. This can be the case if the pump vanes are formed quite flat in width and height. In this case, the central area can also be formed with less material.
[0019] One advantage is that at least one energy director is formed in a flat plane within at least one groove, which forms a materially bond with the rib structure of the pump impellers after welding. The at least one energy director is inserted on a flat plane in the base body and fuses with the rib structure of the pump impellers during welding. By inserting the at least one energy director on a flat plane in the base body, the weld seam is at the same height everywhere, i.e. in every groove; this means that the wall thickness up to the weld seam is the same everywhere. As a result, the introduced sound travels the same path everywhere, for example in ultrasonic welding. A further advantage is that the base body can be more easily manufactured and measured in the injection mold. This also applies when there are multiple mold cavities.In a further development, the cover plate is connected to the base body using laser welding or ultrasonic welding. With laser welding, the base body is made of a laser-transparent material, and the cover plate with the pump blades is made of a laser-absorbing material. With ultrasonic welding, the base body and the cover plate with the majority of pump blades are made of a thermoplastic material. By constructing the cover plate and the base body from thermoplastic material, it is possible to connect the cover plate to the base body in a force-fitting and / or material-fitting manner using a welding process.
[0020] According to the invention, a sonotrode is placed on the back of the base body during ultrasonic welding. The flat back of the base body allows the sonotrode to be placed flat, thus forming a longer weld seam. The sonotrode's flat support on the back of the base body allows it to be used for different impeller sizes. This eliminates the need for a molded sonotrode for different impeller sizes, resulting in lower acquisition and setup costs. Furthermore, there is no need to intervene in the ultrasonic system, as only the component holder needs to be replaced for a different impeller size. This leads to lower manufacturing costs for the impeller, the component holder can be changed quickly, and the ultrasonic system can be easily coded using an automatic ultrasonic welding program call.A further advantage is that a uniform material thickness is achieved over the entire length of the weld.
[0021] It is advantageous that a hold-down mask is placed on the back of the base body during laser welding. The flat back of the base body means the hold-down mask can be placed flat, thereby forming a longer weld seam. The hold-down mask can be used for different impeller sizes thanks to its flat support on the back of the base body. This means that no changes to the hold-down mask are required for different impeller sizes, resulting in lower acquisition and setup costs. A further advantage is that the same / uniform material thickness is formed over the entire length of the weld seam. In a further development, the base body and the cover plate each have at least one corresponding recess intended for fastening in a tool. The recess in the cover plate and the base body allows them to be inserted into the correct position in the welding tool.Alternatively, the recess in the cover plate and the base body can also be omitted.
[0022] The invention is not limited to the embodiments mentioned. Rather, it encompasses all possible embodiments that can be implemented within the scope of expert practice and with minor modifications by a person skilled in the art.
[0023] Embodiments of the invention are explained in more detail below with reference to the drawings. They show:
[0024] Fig. 1 a plan view of the impeller according to the invention
[0025] Fig. 2 a spatial representation of the cover plate
[0026] Fig. 3 a top view of the base body
[0027] Fig. 4 a sectional view of the base body according to Fig. 3
[0028] Fig. 5 a rear view of the base body according to Fig. 3
[0029] Fig. 1 shows a plan view of the impeller (1) according to the invention for a liquid pump, comprising a cover plate (2) and a base body (3), wherein an intake channel (4) is arranged on the cover plate (2), wherein a plurality of pump vanes (5) (not visible here) are formed integrally with the cover plate (2), wherein the base body (3) has a receptacle (7) for an impeller bearing bush (not shown here) in a central region (6), and wherein the cover plate (2) is connected to the base body (3) via at least one pump vane (5) by means of a welding process. The cover plate (2) with the plurality of pump vanes (5) and the base body (3) are made of a thermoplastic material.
[0030] Fig. 2 shows a spatial representation of the cover plate (2). An intake channel (4) is arranged in the center of the cover plate (2). A plurality of pump vanes (5) are formed integrally with the cover plate (2). The pump vanes (5) have a uniform width at least in sections and extend from a root (8) to a tip (9) in a concave curve on the cover plate (2). On at least one pump vane (5) on a side opposite the base body (3) (not shown here), at least one axially extending rib structure (10) is formed in sections. On the tip (9) of at least one pump vane (5), at least one crown structure extending axially in the direction of the base body (3) is formed.
[0031] (11). At least one recess (21) is provided in an edge region of the cover plate (2), which corresponds to a recess (21) in the base body (3) (not shown here). The at least one recess (21) serves to fasten the cover plate (2) and the base body (3) in a tool.
[0032] Fig. 3 shows a plan view of the base body (3) with a central region (6) that has a greater wall thickness than in an edge region (12). A plurality of grooves (14) that correspond to the majority of the pump vanes (5) are formed on the end face (13) of the base body (3). Within at least one groove (14), at least one energy director (19) is formed in a flat plane that is integrally connected to the rib structure (10) of the pump vanes (4) (not shown here) after the welding process. The grooves (14) are deeper in the central region (6) than in the edge region (12). Recesses (16) are defined in the edge region (12). The grooves (14) extend into the edge region (12) and merge into the recesses (16) there. The recesses (16) form a toothed structure (17) in the edge region (12) of the base body (3), in the form of several saw teeth. The toothed structure (17) forms the counter-contour to the crown structure (11).At least one recess (21) is provided on the base body (3) in the edge region (12), which corresponds to a recess (21) on the cover plate (2) (not shown here). The at least one recess (21) serves to fasten the cover plate (2) and the base body (3) in a tool.
[0033] Fig. 4 shows a sectional view of the base body (3) according to Fig. 3. The base body (3) has a higher wall thickness in the central area (6) than in the edge area
[0034] (12). In the central region (6), a receptacle (7) for a wheel bearing bush is formed, into which a wheel bearing bush is received before or after the welding process by pressing, injection molding, or other fastening methods known to those skilled in the art. A plurality of grooves (14) are formed on the front side (13) of the base body, in which at least one energy director (19) is formed in a flat plane. On the rear side (15), the base body (3) is flat and has at least one recess (18) in the central region (6).
[0035] Fig. 5 shows a rear view of the base body (3) according to Fig. 3. On the rear side (15) of the base body (3), a receptacle (7) for a wheel bearing bush and at least one recess (18) are formed in the central region (6). The grooves (14) extend into the edge region (12) and define recesses (16) therein which form a toothed structure (17) in the form of several saw teeth. A recess (21) is formed in the edge region (12) and is designed for fastening the base body (3) in a tool. A sonotrode (20) or a hold-down mask (not shown here) is placed on the rear side (15) of the base body (3) during ultrasonic welding or laser welding.
[0036] List of reference symbols
[0037] 1. Wheel
[0038] 2. Cover plate
[0039] 3. Basic body
[0040] 4. Intake duct
[0041] 5. Pump impeller
[0042] 6. Central area
[0043] 7. Recording
[0044] 8. Root
[0045] 9. Tip
[0046] 10. Rib structure
[0047] 11. Crown structure
[0048] 12. Edge area of the base body
[0049] 13. Front side
[0050] 14. Grooves
[0051] 15. Back
[0052] 16. Recess
[0053] 17. Tooth structure
[0054] 18. Deepening
[0055] 19. Energy director
[0056] 20. Sonotrode
[0057] 21. Recess
Claims
PATENT CLAIMS Impeller (1) for a liquid pump with a cover plate (2) and a base body (3), wherein an intake channel (4) is arranged on the cover plate (2), wherein a plurality of pump vanes (5) are formed integrally with the cover plate (2), wherein the base body (3) has a receptacle (7) for an impeller bearing bush in a central region (6), and wherein the cover plate (2) is connected to the base body (3) via at least one pump vane (5) by means of a welding process. Impeller according to claim 1, wherein the pump vanes (5) have a uniform width at least in sections and extend in a concave curve from a root (8) to a tip (9) on the cover plate (2). Impeller according to one of the preceding claims, wherein at least one axially extending rib structure (10) is formed in sections on at least one pump vane (5) on a side opposite the base body. Impeller according to one of the preceding claims, wherein at least one crown structure (11) extending axially in the direction of the base body (3) is formed on the tip (9) of at least one pump vane (5). Impeller according to one of the preceding claims, wherein the base body (3) has a greater wall thickness in the central region (6) than in an edge region (12). Impeller according to one of the preceding claims, wherein the base body (3) has a plurality of grooves (14) on an end face (13) which correspond to the pump vanes (5), and wherein the base body (3) is flat on its rear side (15). Impeller according to claim 5 or 6, wherein the grooves (14) are deeper in the central region (6) than in the edge region (12). Impeller according to one of the preceding claims, wherein the grooves (14) extend into the edge region (12) of the base body (3) and define recesses (16) in the edge region (12) of the base body (3).Impeller according to one of the preceding claims, wherein the recesses (16) in the edge region (12) of the base body (3) form a toothed structure (17). Impeller according to one of the preceding claims, wherein the base body (3) has at least one depression (18) on its rear side (15) in the central region (6). Impeller according to one of the preceding claims, wherein at least one energy director (19) is formed in a flat plane within at least one groove (14), which energy director is in a materially bonded connection with the rib structure (10) of the pump vanes (5) after welding. Impeller according to one of the preceding claims, wherein the cover plate (2) is connected to the base body (3) by means of laser welding or ultrasonic welding. Impeller according to one of the preceding claims, wherein a sonotrode (20) is placed on the rear side (15) of the base body (3) during ultrasonic welding. Impeller according to one of the preceding claims, wherein a hold-down mask (20) is placed on the rear side (15) of the base body (3) during laser welding. Impeller according to one of the preceding claims, wherein the base body (3) and the cover plate (2) each have at least one corresponding recess (21) provided for fastening in a tool.