Coolant pump, in particular for motor vehicles, with a pumping device

Abstract

Pump device (2), in particular for a pump (1), preferably used for a motor vehicle, in particular a coolant pump (1), with at least one housing part (3) and a bearing bush (14), wherein a rotor (15) can be mounted at least indirectly on the housing part (3) with respect to a rotor axis (16) by means of the bearing bush (14).It is proposed that an axial bearing body (17) is provided on which an axial bearing surface (18) is formed, that a bearing bush surface (19) is formed on the bearing bush (14), which bearing bush surface is supported at least during operation in an at least approximately annular contact region (20) on the axial bearing surface (18) of the axial bearing body (17), that the annular contact region (20) extends in a circumferential direction (26) around the rotor axis (16), and that at the contact region (20) a contact surface (27) between the axial bearing surface (18) and the bearing bush surface (19) is smaller than an area (20A) of the annular contact region (20). Furthermore, a pump (1) and a method for assembling the pump (1) are specified.

Description

State of the art

[0001] The invention relates to a coolant pump, in particular for motor vehicles, and a pump device for such a coolant pump. The invention specifically relates to the field of passenger cars (PCs) and trucks (Trucks).

[0002] A pump and a pump device are known from DE 10 2022 204 154 A1. The known pump comprises a rotor receiving unit for receiving a rotor unit and a bearing unit for supporting the rotor unit. The bearing unit has a running surface for the rotor unit on its casing.

[0003] A wide range of applications is conceivable for a coolant pump, which can be designed as an electronically commutated centrifugal pump, such as supporting the heating circuit, cooling the interior, utilizing residual heat, and cooling components, as well as for turbochargers and intercoolers. The low noise level and long service life also enable its use in hybrid and electric vehicles, where it can be used, for example, to cool power electronics modules or a drive battery.

[0004] In such a coolant pump, sliding contacts can be used for the pump rotor. The axial contact surfaces of the contacts can be designed to be plane-parallel. The plain bearing bush preferably has a combined function: The bushing can provide radial guidance on the stationary shaft and axial support on both sides. Depending on the installation position, the rotor and bushing can rest on one side and then lift off during operation. The contact of the plane-parallel surfaces can lead to an unfavorable lubrication condition, especially when the pump is at a standstill and starting up. Disclosure of the invention

[0005] The pump device according to the invention with the features of the main claim and the pump with the features of claim 10, as well as the method according to claim 11, have the advantage of enabling an improved design and functionality. This, in particular, enables improved pump start-up.

[0006] The rotor is not necessarily a component of the pump device according to the invention. In particular, the pump device can also be manufactured and sold independently of a rotor.

[0007] The measures listed in the subclaims also result in advantageous developments and improvements of the features specified in the main claim.

[0008] It is advantageous that the axial bearing body can be arranged at least substantially stationary on the rotor. In this case, the axial bearing body can be connected to a rotor in a suitable manner. The axial bearing body can also be a component of the rotor.

[0009] It is advantageous for the bearing bush to be arranged at least substantially stationary on the housing part. For example, the housing part can be designed as a pot-shaped housing part, in particular as a housing pot. The housing pot can at least partially enclose the rotor when the pump is assembled.

[0010] It is advantageous that, at least in the contact area, the axial bearing surface or the bearing bushing surface is designed with a contour that allows the gap height, viewed along the rotor axis, to vary across the annular contact area. This can effectively reduce the tendency for adhesion.

[0011] In particular, direct contact between a material of the thrust bearing and a material of the bearing bush can occur during rotor standstill. Especially if this material pairing has a high tendency to adhere, a relatively large contact area could result in a high coefficient of static friction or high static friction forces during start-up. This could significantly reduce the starting torque.

[0012] The proposed and advantageously developed solution allows the contact area to be significantly reduced in such a situation. This can significantly reduce the static friction coefficient and thus reduce static friction forces during start-up. This prevents a reduction in the starting torque.

[0013] It is advantageous that, at least in the contact area, the axial bearing surface and the bearing bushing surface are designed with contours that do not interlock with each other in the circumferential direction, allowing the gap height viewed along the rotor axis to vary across the annular contact area. This allows, for example, a contoured surface design to be realized on both contact partners. This allows for further optimization in the respective application.

[0014] It is advantageous that, at least in the contact area, the axial bearing surface and / or the bearing bushing surface are designed to be wave-shaped, at least in the circumferential direction, so that a gap height viewed along the rotor axis varies in the circumferential direction across the annular contact area. This allows, in particular, a specific number of contact points (contact points or contact surfaces) to be realized. This allows the resulting static friction coefficient to be specified. This allows the starting behavior of the rotor to be optimized. Furthermore, the running behavior of the rotor during operation can be optimized.

[0015] It is advantageous that, at least in the contact area, the axial bearing surface and the bearing bushing surface are designed, at least in the circumferential direction, such that contact between the axial bearing surface and the bearing bushing surface always exists at at least three given angular positions relative to the rotor axis. This allows for a defined support.

[0016] It is advantageous that the number of angular positions at which contact exists between the axial bearing surface and the bearing bush surface is not greater than 15. This allows for advantageous optimization with regard to both the coefficient of static friction and wear resistance.

[0017] For example, three angular positions can be provided. The angular distance between the angle lengths can then be approximately 120° in pairs. Accordingly, the same angular distance can be specified between adjacent angular positions in pairs if more than three angular positions are provided. However, different angular distances can also be implemented.

[0018] It is advantageous that adjacent angular positions are spaced apart by no more than approximately 8 mm in the circumferential direction. This allows for a particularly advantageous waviness, which enables optimization of the coefficient of static friction and wear resistance.

[0019] For example, with a diameter of 40 mm on the rotor side and approximately 15 angular contact positions, a contact point (contact point or contact surface) can be realized approximately every 8 mm. A larger angular spacing between the contact points also allows the distance between the contact points to be increased. This allows for optimization, particularly with regard to the coefficient of static friction and wear resistance. The optimization can be carried out with respect to the respective material pairing. In particular, the adhesion tendency of the material pairing can be taken into account.

[0020] It is advantageous that the average amplitude of the gap height variation is greater than the surface roughness of the axial bearing surface or the surface roughness of the bearing bush surface. This effectively reduces static friction forces.

[0021] It is advantageous that the average amplitude of the gap height variation is smaller than the axial bearing clearance between the thrust bearing body and the bearing bush. This enables reliable operation.

[0022] It is advantageous that an operating position of the pump device is predetermined and that, in the operating position, the axial bearing body and the bearing bush are in direct contact with one another in the annular contact area, at least in a resting state. This can effectively ensure the reduction of static friction forces. In the respective application, it is also conceivable that the proposed design is also used on another axial bearing of the pump, so that a reduction of static friction forces is possible regardless of the installation position. However, especially in the case of fixed installation, for example in the engine compartment of a motor vehicle, an installation position can usually be predetermined.

[0023] It is advantageous that the axial bearing body and the bearing bush are designed in such a way that, when the rotor is brought down, local wear between the axial bearing surface and the bearing bush surface is at least largely avoided. This can be optimized with respect to the respective material pairing, for example, by increasing the number of contact areas.

[0024] Depending on the design, one or more of the following features and advantages can be realized.

[0025] When the pump is at a standstill, a flat contact between the thrust bearing materials could lead to a high coefficient of static friction if there is no lubricant between the surfaces. The larger the actual contact surface, the smaller the gap available for lubricant. Surface adhesion also increases.

[0026] The proposed solution, which may be advantageously further developed, can reduce the coefficient of static friction.

[0027] By appropriately contouring one or both contact surfaces, especially those designed as flanged contact surfaces, the large-area contact between the contact partners can be reduced. This can lead to a reduced starting torque and the associated static friction coefficient, particularly for materials with a high tendency to adhere to the material pair.

[0028] The flange contact surface can be geometrically designed to reduce the actual contact surface. Wave structures, for example, are possible. The amplitude should be selected to be larger than the roughness and significantly smaller than the axial bearing clearance. The wave length can be adjusted depending on the diameter and the manufacturing process.

[0029] Contouring only one contact partner is advantageous. Contouring both contact partners is also possible. Care must be taken to prevent geometric interlocking. In addition to a wave shape, other shapes with oblique or other profile contours are also possible.

[0030] When shutting down the pump, the rotor may sink, especially if installed vertically. The rotor can slow down and decelerate due to fluid forces and mixed friction on the thrust bearing. It is particularly important to ensure that local wear does not lead to the destruction of the contour due to the thrust bearing coming down when shutting down the pump. Short description of the drawings

[0031] Preferred embodiments of the invention are explained in more detail in the following description with reference to the accompanying drawings, in which corresponding elements are provided with identical reference numerals. They show: Fig. 1 shows a pump with a pump device in a schematic, highly simplified and not to scale sectional view according to a first embodiment; Fig. 2 a detail of the Fig. 1 shown pump device of the pump in a schematic, highly simplified and not to scale sectional view and Fig. 3 a bearing bush designed as an axial and radial bearing bush of the Fig. 2 shown pump device according to a second embodiment in a schematic, highly simplified and not to scale spatial representation. Embodiments of the invention

[0032] Fig. Figure 1 shows a pump 1 with a pump device 2 in a schematic, highly simplified, and not-to-scale sectional view according to a first exemplary embodiment. The pump 1 can be used in particular for a motor vehicle. Specifically, the pump 1 can be designed as a coolant pump 1. The pump device 2 is particularly suitable for such pumps 1.

[0033] The pump device 2 has a housing part 3. In this exemplary embodiment, the housing part 3 is designed as a pot 3. The pump device 2 can be used to manufacture a pump 1. In the assembled state, the housing part 3, in particular the pot 3, can be part of a housing 4 of the pump 1. The housing 4 of the pump 1 can, for example, have a further housing part 5. The housing part 3 and the further housing part 5 are connected to one another by means of screw connections 10.

[0034] In this exemplary embodiment, the pump 1 has a shaft 6, which, in the assembled state, can be connected to an output shaft at an interface 7. The shaft 6 has a first end 8 and a second end 9, with the interface 7 being provided at the second end 9.

[0035] The pump device 2 has a bearing bush 14. A rotor 15 of the pump 1 is mounted on the housing part 3 by means of the bearing bush 14 with respect to a rotor axis 16. In this exemplary embodiment, the rotor 15 is mounted at the first end 8 by means of the bearing bush 14.

[0036] In this exemplary embodiment, the bearing bush 14 is a component of the housing part 3. The housing part 3 thus has the bearing bush 14. In a modified embodiment, the bearing bush 14 can, for example, also be designed as a separate component that is connected to the housing part 3, in particular the pot 3, during assembly.

[0037] The design of the pump 1 and the pump device 2 is described below with reference to the Fig. 2 is further explained.

[0038] Fig. 2 shows a detail of the Fig. 1, in a schematic, highly simplified, and not-to-scale sectional view of the pump device 2 of the pump 1. The pump device 2 has an axial bearing body 17. An axial bearing surface 18 is formed on the axial bearing body 17. A bearing bush surface 19 is formed on the bearing bush 14, associated with the axial bearing surface 18. The bearing bush surface 19 is supported, at least during operation, in an at least approximately annular contact area 20 on the axial bearing surface 18 of the axial bearing body 17.

[0039] The annular contact area 20 extends around the rotor axis 16 in a circumferential direction 26. Between the axial bearing surface 18 and the bearing bush surface 19, there is contact at several contact points located within a contact area 20. Viewed at the contact points, the total contact area 27 is at least approximately located within the contact area 20. The contact area 27 between the axial bearing surface 18 and the bearing bush surface 19 is smaller than an area 20A of the annular contact area 20.

[0040] In this embodiment, the axial bearing body 17 is arranged stationary on the rotor 15. Depending on the design, the axial bearing body 17 can also be a component of the rotor 15.

[0041] In this exemplary embodiment, the bearing bush 14 is arranged in a fixed position on the housing part 3. In this exemplary embodiment, the bearing bush 14 is formed on the housing part 3, which is designed as a pot (housing pot).

[0042] In the contact area 20 in the Fig. In the first embodiment shown in Figure 1, the axial bearing surface 18 is designed with a contour 30.

[0043] Possible configurations are described below with reference to Fig. 3 explained.

[0044] Fig. 3 shows a bearing bush 14 designed as an axial and radial bearing bush 14 of the Fig. 2 shown pump device 2 according to a second embodiment in a schematic, highly simplified and not to scale spatial representation.

[0045] In the Fig. In the second embodiment shown in Fig. 3, the bearing bush surface 19 is designed with a contour 31 in the contact area 20.

[0046] Depending on the design of the pump 1 or the pump device 2, both the axial bearing surface 18 and the bearing bush surface 19 can be designed with a contour 30, 31. A contour 30 can also be designed either on the axial bearing surface 18 or a contour 31 on the bearing bush surface 19. Thus, a suitable design can be selected for the respective application.

[0047] Between the axial bearing surface 18 and the bearing bush surface 19, a positive or non-vanishing gap height 32 exists due to a contouring 30, 31 or both contourings 30, 31 outside the contact points. The gap height can be observed along the rotor axis 16. The gap height 32 disappears at the contact points between the axial bearing surface 18 and the bearing bush surface 19. Thus, the gap height 32 varies across the annular contact area 20.

[0048] If both the axial bearing surface 18 and the bearing bush surface 19 are provided with contours 30, 31, then these are designed, at least in the contact area 20, with contours 30, 31 that do not interlock with each other in the circumferential direction 26. The contours 30, 31 are further designed such that contact points are created and that non-zero or positive gap heights 32 are present outside the contact points. This results in a design in which the gap height 32 viewed along the rotor axis 16 varies across the annular contact area 20.

[0049] In preferred embodiments, as in Fig. 1 and Fig. 3, the axial bearing surface 18 and / or the bearing bush surface 19 may be wave-shaped in the contact area 20, as viewed in the circumferential direction 26. The wave shape is not shown to scale and is scaled so that it is clearly visible in the illustrations.

[0050] The design of one or both contours 30, 31 in the form of wave-shaped configurations is selected in this embodiment such that the gap height 32 viewed along the rotor axis 16 varies over the annular contact region 20 at least in the circumferential direction 26.

[0051] As it is in Fig. 2 and Fig.3, the axial bearing surface 18 and the bearing bush surface 19 in the contact region 20, at least viewed in the circumferential direction 26, are designed such that there is always contact between the axial bearing surface 18 and the bearing bush surface 19 at at least three angular positions 35 given with respect to the rotor axis 16. This means that, regardless of the relative rotational angular position of the rotor 15 to the housing 4, in particular housing part 3, there is contact between the axial bearing surface 18 and the bearing bush surface 19 at three angular positions 35 given with respect to the rotor axis 16.

[0052] Preferably, the number of angular positions 35 at which there is contact between the axial bearing surface 18 and the bearing bush surface 19 is not greater than 15. It is also advantageous that, viewed in the circumferential direction 26, adjacent angular positions 35 are spaced apart in pairs by no more than approximately 8 mm.

[0053] An average amplitude 36 of the variation of the gap height 32 is greater than a surface roughness of the axial bearing surface 18. Furthermore, an average amplitude 36 of the variation of the gap height 32 is greater than a surface roughness of the bearing bush surface 19.

[0054] An average amplitude 36 of the variation of the gap height 32 is preferably significantly smaller than an axial bearing clearance between the axial bearing body 17 and the bearing bush 14.

[0055] For the assembled state, an operating position 40 of the pump device 2 or the pump 1 can be predetermined. The operating position 40 can be determined, for example, by an installation situation in an engine compartment or at another mounting location in the motor vehicle. In the operating position 40, the axial bearing body 17 and the bearing bush 14 are in direct contact with each other in the annular contact area 20, at least in a resting state.

[0056] For example, in the idle state, a lubricant can be displaced from the contact area 20. Especially when the pump 1 starts up, the size of the total area (contact area) 20A of the contact area 20, which results from the partial areas 45 at the contact points, in particular at the angular positions 35, can have a significant influence on the resulting static friction.

[0057] If the static friction is high, it acts as a brake. This subsequently reduces power and leads to a higher resistance moment. Since the area 20A can be significantly reduced by the proposed and, if appropriately further developed, relative to the annular contact area 20, which has an annular surface, the static friction is significantly reduced. This results in higher power and a lower resistance moment, particularly when starting up the pump 1.

[0058] The axial bearing body 17 and the bearing bush 14 are designed in such a way that when the rotor 15 is lowered, local wear between the axial bearing surface 18 and the bearing bush surface 19 is avoided.

[0059] Thus, a pump 1 can be realized that serves in particular for a motor vehicle and can be designed as a coolant pump 1. The rotor 15 can be mounted at least indirectly on the housing part 3 by means of the bearing bush 14 with respect to the rotor axis 16.

[0060] Furthermore, in a method (assembly method) for assembling the pump 1, the rotor 15 and the pump device can be assembled such that the rotor 15 is mounted at least indirectly on the housing part 3 with respect to the rotor axis 16 by means of the bearing bush 14 of the pump device 2.

[0061] The invention is not limited to the described embodiments. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 204 154 A1

[0002]

Claims

[1] Pump device (2), in particular for a pump (1) preferably used for a motor vehicle, in particular a coolant pump (1), with at least one housing part (3) and a bearing bush (14), wherein a rotor (15) can be mounted at least indirectly on the housing part (3) with respect to a rotor axis (16) by means of the bearing bush (14), characterized bythat an axial bearing body (17) is provided, on which an axial bearing surface (18) is formed, that a bearing bush surface (19) is formed on the bearing bush (14), which bearing bush surface is supported at least during operation in an at least approximately annular contact region (20) on the axial bearing surface (18) of the axial bearing body (17), that the annular contact region (20) extends in a circumferential direction (26) around the rotor axis (16) and that at the contact region (20) a contact surface (27) between the axial bearing surface (18) and the bearing bush surface (19) is smaller than an area (20A) of the annular contact region (20). [2] Pump device according to claim 1, characterized by that the axial bearing body (17) can be arranged at least substantially stationary on the rotor (15) and / or that the bearing bush (14) is arranged at least substantially stationary on the housing part (3). [3] Pump device according to claim 1 or 2, characterized by , a) that at least in the contact area (20) the axial bearing surface (18) or the bearing bush surface (19) is designed with a contour (30, 31) by means of which a gap height (32) viewed along the rotor axis (16) varies over the annular contact area (20), or b) that at least in the contact region (20) the axial bearing surface (18) and the bearing bush surface (19) are designed with contours (30, 31) which do not mesh with one another in the circumferential direction (26), by means of which a gap height (32) viewed along the rotor axis (16) varies over the annular contact region (20). [4] Pump device according to one of claims 1 to 3, characterized bythat at least in the contact region (20) the axial bearing surface (18) and / or the bearing bush surface (19) is designed to be wave-shaped at least in the circumferential direction (26), so that a gap height (32) viewed along the rotor axis (16) varies over the annular contact region (20) in the circumferential direction (26). [5] Pump device according to claim 4, characterized by that at least in the contact region (20) the axial bearing surface (18) and the bearing bush surface (19) are designed, at least in the circumferential direction (26), such that there is always contact between the axial bearing surface (18) and the bearing bush surface (19) at at least three angular positions (35) given with respect to the rotor axis. [6] Pump device according to claim 5, characterized by , a) that the number of angular positions (35) at which there is contact between the axial bearing surface (18) and the bearing bush surface (19) is not greater than 15 and / or b) that adjacent angular positions (35) viewed in the circumferential direction (26) are spaced apart in pairs by no more than approximately 8 mm. [7] Pump device according to one of claims 3 to 6, characterized by that an average amplitude (36) of the variation of the gap height (32) is greater than a surface roughness of the axial bearing surface (18) or a surface roughness of the bearing bush surface (19). [8] Pump device according to one of claims 3 to 7, characterized by that an average amplitude (36) of the variation of the gap height (32) is smaller than an axial bearing clearance between the axial bearing body (17) and the bearing bush (14). [9] Pump device according to claim 8, characterized bythat an operating position (40) of the pump device (2) is predetermined and that in the operating position (40) the axial bearing body (17) and the bearing bush (14) in the annular contact region (20) are in direct contact with one another at least in a rest state. [10] Pump device according to one of claims 1 to 9, characterized by that the axial bearing body (17) and the bearing bush (14) are designed such that when the rotor (15) is lowered, local wear between the axial bearing surface (18) and the bearing bush surface (19) is at least substantially avoided. [11] Pump (1), in particular preferably a coolant pump for a motor vehicle, with at least one pump device (2) according to one of claims 1 to 10 and at least one rotor (15) which is mounted at least indirectly on the housing part (3) with respect to the rotor axis (16) by means of the bearing bush (14). [12] Method for assembling a pump (1), in particular a coolant pump preferably used for a motor vehicle, wherein a rotor (15) and a pump device (2) according to one of claims 1 to 10 are assembled such that the rotor (15) is mounted at least indirectly on the housing part (3) with respect to the rotor axis (16) by means of the bearing bush (14) of the pump device (2).

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