Pump

Abstract

Pump (1) with a pump housing (2) with an intake opening and with an outlet opening (3), with a drivable pump wheel (4) arranged in the pump housing (2), by means of which a fluid can be conveyed from the intake opening to the outlet opening (3), wherein a slide (7) which is displaceable in the axial direction is provided in the pump housing (2), wherein the slide (7) is displaceable radially outside the pump wheel (4) in the axial direction over the pump wheel (4), wherein the slide (7) is displaceable in the axial direction by an actuator (8) by means of at least one axially displaceable push rod (9), characterized in that the axial position and / or the axial displacement of the at least one push rod (9) can be influenced by a magnetorheological braking element (14).

Description

[0001] The invention relates to a pump, in particular a water pump for a water circuit of a motor vehicle.

[0002] Pumps, and especially water pumps, are used in motor vehicles to circulate water through the coolant system, for example, to cool the engine and possibly other components. Water flows through the engine as a coolant and is heated there. The coolant then flows through a radiator, where it is cooled again through heat exchange, for example with air, before being pumped back to the engine.

[0003] The required pumping capacity is not always at its maximum, but can be reduced depending on the vehicle's operating conditions. The pumping capacity is particularly dependent on the drive system. If the pump is driven by the vehicle's own motor, the pump's speed is determined by the motor's speed, which does not necessarily correlate with the required pumping capacity.

[0004] Therefore, a controllable pump is generally desirable. However, very complex solutions are rather unsuitable for automotive applications because they always increase costs, which is often unacceptable in automotive manufacturing.

[0005] DE 10 2011 076 719 A1 discloses a coolant pump driven by a traction drive for the coolant supply of an internal combustion engine.

[0006] DE 198 25 367 A1 discloses a hydraulic displacement machine with a ring chamber filled with an electrorheological and / or magnetorheological fluid and a piston.

[0007] DE 10 2004 054 637 A1 discloses a controllable coolant pump with a magnetically operated valve slide.

[0008] The object of the present invention is to create a pump that is simple and inexpensive in design and yet allows for good controllability.

[0009] The problem is solved using the features of claim 1.

[0010] One embodiment of the invention relates to a pump with a pump housing having an inlet and an outlet, and with a driven impeller arranged in the pump housing by means of which a fluid can be conveyed from the inlet to the outlet. A slide is provided in the pump housing, which is axially displaceable. The slide is axially displaceable outside the impeller and over the impeller. The slide is axially displaceable by an actuator via at least one axially displaceable push rod. The axial position and / or displacement of the push rod can be influenced by a magnetorheological braking element. The fluid flow of the pump can be adjusted or controlled by means of the slide, which is axially displaceable outside the impeller.When the slide valve is fully retracted, the maximum flow rate can be achieved; when it is fully extended, the flow rate can be completely stopped. If the slide valve is in an intermediate position between these two, the flow rate can be adjusted accordingly. Simple and stable flow control requires easy movement and secure positioning. The inclusion of at least one braking element ensures that the slide valve can be held securely in a set position.

[0011] According to the invention, it is advantageous to provide a plurality of push rods, which can be actuated by the actuator and by means of which the slide can be axially displaced. This allows the applied force to be distributed more effectively.

[0012] This allows a number of pushrods to be distributed around the circumference of the valve to ensure even loading, preventing it from tilting and jamming when the pushrods are applied. This increases the pump's service life.

[0013] It is particularly advantageous if each pushrod is assigned a magnetorheological braking element. This allows for improved positioning of the pushrod, as each pushrod can be adjusted and held in place. This improves the overall positioning of the slide and thus the pump's delivery accuracy.

[0014] Furthermore, it is also advantageous if the magnetorheological brake element has a brake housing in which a chamber is formed through which the push rod is guided, the chamber being filled with a magnetorheological material. This allows the positioning of the push rod to be achieved in a particularly simple manner.

[0015] According to the invention, it is also advantageous if at least one magnetic field-generating element is provided to generate a magnetic field in the region of the magnetorheological material. The magnetic field-generating element can generate a magnetic field for all brake elements together, or alternatively, the magnetic field-generating element can be provided in such a way that a plurality of such elements are provided, each assigned to a brake element. In this way, the magnetic field-generating element can be assigned to and attached to each brake element.

[0016] Preferably, a magnetic field-generating element is an electromagnet or a coil, wherein the magnetic field-generating element is arranged on and / or around the brake housing.

[0017] It is also advantageous to have a piston-like element inside the brake housing, connected to the pushrod and movable through the magnetorheological material. This ensures good force transmission between the magnetorheological material and the pushrod.

[0018] It is particularly advantageous if the piston-like element is a flange projecting radially from the pushrod. This allows for good force transmission with a simple design. The flange can move within the brake housing along the direction of movement of the pushrod, and depending on the viscosity of the magnetorheological material, this results in good braking or holding performance.

[0019] It is also advantageous if the brake housing has a hollow cylindrical ring wall and two axially spaced end walls, each with an opening through which the pushrod passes. This creates a kind of cylinder chamber in which the piston-like element can move like a piston. This results in a simple design.

[0020] It is particularly advantageous if the brake element, with its annular wall, is held in a receptacle in the pump housing. This ensures that the brake element is held securely, allowing a force applied to the push rod to be transmitted directly to the slide.

[0021] It is particularly advantageous if the actuator for actuating the at least one push rod is a hydraulic or pneumatic actuator that acts on the at least one push rod via an actuating element, such as a pressure ring. This allows for simple and cost-effective design and control with good force transmission. In combination with the at least one braking element, good controllability of the slide can be achieved.

[0022] The invention will now be explained in detail using an exemplary embodiment and with reference to the drawing. The drawing shows: Fig. 1 a schematic perspective, partially cutaway view of an exemplary embodiment of a pump, Fig. 2 a cutaway view of part of the pump according to Fig. 1, Fig. 3 a perspective view of part of the pump according to Fig. 1, and Fig. 4 a sectional view of a brake element.

[0023] The Fig. Figure 1 shows a pump 1 in a partially cutaway view. The pump 1 has a pump housing 2 which has an intake opening and an outlet opening 3. However, the intake opening is not shown because the front housing cover of the pump housing is omitted to show details of the pump.

[0024] A rotatable and driveable impeller 4 is arranged in the pump housing 2, which, when rotated, conveys a fluid from the intake opening to the outlet opening 3. For this purpose, the impeller 4 has a structure of vanes and / or profiles to enable the conveying of the fluid when the impeller 4 rotates. In the exemplary embodiment of the Fig. 1. The impeller 4 conveys the fluid from an axial flow direction at the intake opening to the radial outside, where it is discharged through the outlet opening 3. Other geometries can also be used, such as a radial intake and an axial discharge.

[0025] The impeller 4 is mounted on a shaft 5 and rotatably connected to it in the pump housing 2. The shaft 5 protrudes from the pump housing 2, where it is connected to a pulley 6 for drive by a belt drive.

[0026] To control the pumped fluid flow, a slide valve 7 is provided in the pump housing 2, which is arranged to be axially displaceable. The slide valve 7 is mounted so as to be axially displaceable and is arranged radially between the pump housing 2 and the impeller 4. The slide valve 7 can be moved between a first axial position and a second axial position. In the first position, the slide valve 7 is in a retracted position and allows radial access to the impeller 4. In the second position, the slide valve extends axially over the impeller 4 and covers it radially outside of the impeller 4. In the first position, the fluid flow delivered by the impeller 4 can be conveyed unaffected by the slide valve 7. In the second position, the fluid flow is interrupted because the slide valve 7 blocks the fluid channel radially outside of the impeller 4.The slide valve can also be set in an axial intermediate position between the first and second positions. Depending on the axial positioning of the slide valve 7, the fluid flow of the pump 1 can be controlled.

[0027] The slide 7 is radially displaceable outside the impeller 4 and axially displaceable over the impeller 4. This is effected by an actuator 8. The actuator is connected to at least one axially displaceable push rod 9, which is supported on one side by the actuator 8 and on the other side by the slide 7. The actuator 8 can actuate the at least one push rod 9 and displace it axially towards the impeller 4 or in the opposite direction away from the impeller 4.

[0028] A single push rod 9 can be provided, or a plurality of push rods 9 can be provided, which can be actuated by the actuator 8 and by means of which the slide 7 can be axially displaced.

[0029] The actuator 8 is advantageously a hydraulic or pneumatic actuator comprising a pressure chamber 10 with a sealing diaphragm cover 11 containing a diaphragm 12. Coupled to the diaphragm 12 is a pressure ring 13, which acts on the respective push rods 9. When pressure is applied to the pressure chamber 10, the pressure ring 13 is actuated or displaced axially, which in turn acts on or displaces the push rods 9.

[0030] To influence the positioning of the slide 7, brake elements 14 are provided that are connected to or interact with the push rods 9. These brake elements 14 are shown in the exemplary embodiment of Fig. 1. The magnetorheological braking element 14 is designed as a magnetorheological braking element. The magnetorheological braking element 14 serves to transmit force to the at least one push rod 9, so that its movement or speed can be controlled. Thus, a force can be exerted by the braking element 14 on the push rod 9, which reduces the speed of the push rod 9's movement. The force can also be dimensioned such that the movement of the push rod 9 is prevented and the push rod 9 is held in place. Accordingly, the axial position and / or the axial displacement of the at least one push rod 9 can be influenced by the at least one magnetorheological braking element 14.

[0031] The Fig. Figure 1 shows a plurality of push rods 9, which are arranged distributed around the circumference of the slide 7. In the exemplary embodiment, the Fig. 1 each push rod 9 is assigned a magnetorheological braking element 14.

[0032] The Fig. 2 and Fig. Figure 3 shows this again in more detail. The push rods 9 are arranged distributed around the circumference of the slide 7. In the exemplary embodiment of the Fig. Three push rods 9 are provided in sections 1 to 3, arranged at an angular interval of 120°, thus acting uniformly on the slide 7. The push rods are acted upon by the pressure ring 13, which in turn is acted upon by springs 23. In the unactuated state, the springs 23 move both the pressure ring 13 and the push rods 9 into their first position.

[0033] The Fig. Figure 4 shows a magnetorheological brake element 14 in a sectional view. The magnetorheological brake element 14 has a brake housing 15 in which a chamber 16 is formed, through which the push rod 9 is guided. The chamber 16 is filled with a magnetorheological material 17. The magnetorheological material 17 is either a dry powder or a fluid, and the material has the property that its elements link together when a magnetic field is applied, thus increasing the viscosity of the magnetorheological material 17. When no magnetic field is applied, the linkage decreases or disappears, and the viscosity of the material decreases.

[0034] The brake housing 15 is formed by a hollow cylindrical ring wall 18 and two axially spaced end walls 19, giving the brake housing 15 an approximately barrel-shaped form. Each of the two end walls 19 has an opening 20 through which the push rod 9 passes. A seal is provided or formed between the end wall 19 and the push rod 9, so that essentially no magnetorheological material 17 can escape from the opening 20.

[0035] The Fig. Figure 1 shows that the brake element 14 with its ring wall 18 is held in a receptacle in the pump housing 2 of the pump 1.

[0036] Within the brake housing 15, a piston-like element 21 is arranged, which is connected to the push rod 9 and is movable through the magnetorheological material 17. The piston-like element 21 is a flange projecting radially from the push rod 9. This flange can be designed such that it has bores or recesses through which the magnetorheological material 17 can flow, and / or it can also be designed such that a gap remains between the radially outer edge of the flange and the inner wall of the brake housing 15, allowing the magnetorheological material 17 to flow through this gap when the push rod 9 moves. The flange or piston-like element 21 divides the chamber 16 into two areas, with the magnetorheological material 17 flowing from one area to the other when the push rod 9 moves.Depending on the viscosity of the magnetorheological material 17, this can lead to a more or less strong braking or even a holding of the push rod 9.

[0037] To generate a magnetic field in the area of ​​the brake element 14 or brake elements 14, at least one magnetic field-generating element 22 is provided to generate a magnetic field in the area of ​​the magnetorheological material 17. The magnetic field-generating element 22 is advantageously designed as an electromagnet or as a coil. The magnetic field-generating element 22 is advantageously arranged on and / or around the brake housing 15. Thus, each brake housing 15 can have its own magnetic field-generating element 22. Alternatively, a single magnetic field-generating element 22 can be assigned to several or all brake elements 14 or brake housings 15. This element can advantageously be arranged around all brake elements 14, and optionally also around the pump housing 2.

[0038] The magnetic field is advantageously controlled by a control unit (not shown) in order to determine the setting of the slider.

[0039] The interaction of a hydraulic or pneumatic actuator and at least one controlled brake element ensures good controllability of the positioning of the slide 7. Reference symbol list 1 pump 2 pump housings 3 Outlet opening 4 Pump wheel 5 wave 6 Pulley 7 sliders 8 Actuator 9 Push rod 10 Printing room 11 Membrane covers 12 Membran 13 Pressure ring 14 Brake element 15 brake housings 16th Chamber 17 magnetorheological material 18 ring wall 19 Front wall 20 Opening 21 piston-like element 22 magnetic field generating element 23 Feder

Claims

[1] Pump (1) with a pump housing (2) having an inlet opening and an outlet opening (3), with a driven impeller (4) arranged in the pump housing (2), by means of which a fluid can be conveyed from the inlet opening to the outlet opening (3), wherein a slide (7) is provided in the pump housing (2), which is axially displaceable, wherein the slide (7) is radially displaceable outside the impeller (4) in the axial direction over the impeller (4), wherein the slide (7) is axially displaceable by an actuator (8) by means of at least one axially displaceable push rod (9), characterized by , that the axial position and / or the axial displacement of at least one push rod (9) can be influenced by a magnetorheological braking element (14). [2] Pump (1) according to claim 1, characterized by, that a plurality of push rods (9) are provided which can be actuated by the actuator (8) and by means of which the slide (7) can be axially displaced. [3] Pump (1) according to claim 2, characterized by , that the majority of push rods (9) are arranged distributed over the circumference of the slide (7). [4] Pump (1) according to one of the preceding claims 2 or 3, characterized by , that each push rod (9) is assigned a magnetorheological braking element (14). [5] Pump (1) according to claim 1 or 4, characterized by , that the magnetorheological brake element (14) has a brake housing (15) in which a chamber (16) is formed through which the push rod (9) is guided, wherein the chamber (16) is filled with a magnetorheological material (17). [6] Pump (1) according to claim 5, characterized by, that at least one magnetic field-generating element (22) is provided to generate a magnetic field in the area of ​​the magnetorheological material (17). [7] Pump (1) according to one of claims 4, 5 or 6, characterized by , that the magnetic field generating element (22) is an electromagnet or a coil which is arranged on and / or around the brake housing (15). [8] Pump (1) according to one of claims 4, 5, 6 or 7, characterized by , that within the brake housing (15) a piston-like element (21) is arranged which is connected to the push rod (9) and which is movable through the magnetorheological material (17). [9] Pump (1) according to claim 8, characterized by , that the piston-like element (21) is a flange projecting radially from the push rod (9). [10] Pump (1) according to any one of claims 4 to 9, characterized by, that the brake housing (15) has a hollow cylindrical ring wall (18) and two axially spaced end walls (19), wherein an opening (20) is formed in each of the two end walls (19) through which the push rod (9) passes. [11] Pump (1) according to any one of claims 4 to 10, characterized by , that the brake element (14) with its ring wall (18) is held in a receptacle in the pump housing (2). [12] Pump (1) according to any one of the preceding claims, characterized by , that the actuator (8) for actuating the at least one push rod (9) is a hydraulic or pneumatic actuator which acts on the at least one push rod (9) via an actuating element, such as a pressure ring (13).

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