DE102021206139A1 - Pump and a vehicle with such a pump - Google Patents

Abstract

Pump (10) for a vehicle, in particular a motor vehicle, for delivering a fluid and a vehicle, in particular a motor vehicle, with such a pump (10) comprising a pump housing (12), with a pump interior (14), an inlet (16) for supplying the fluid into the pump interior (14) and an outlet (18) for discharging the fluid from the pump interior (14), an impeller (22), the impeller (22) having a plurality of impeller blades (24), the impeller (22) and/or the impeller blades (24) is arranged at least partially inside the pump interior (14), the pump housing (12) having a damping device (26) for locally reducing a at the radially outer ends (28) of the impeller blades (24). generated pressure.

Description

State of the art

The invention relates to a pump for a vehicle, in particular a motor vehicle, for pumping a fluid, having the features of claim 1, and a vehicle, in particular a motor vehicle, having the features of the independent claim.

Pumps are used, for example, in a vehicle to convey a coolant fluid within a coolant circuit. Centrifugal pumps in particular are used here. During the operation of such centrifugal pumps, disturbing noises can arise, in particular due to pressure fluctuations. Particularly in the case of electric vehicles, in which there is no background noise from an internal combustion engine, it is desirable to reduce or avoid the noise produced during the operation of such a pump.

Disclosure of Invention

The problem on which the invention is based is solved by a pump for a vehicle, in particular a motor vehicle, for pumping a fluid with the features of claim 1 and a vehicle, in particular a motor vehicle, with the features of the independent claim. Advantageous developments of the invention are specified in the dependent claims.

According to the invention, a pump for a vehicle, in particular a motor vehicle, is proposed for pumping a fluid, comprising a pump housing with a pump interior, an inlet for supplying the fluid into the pump interior and an outlet for discharging the fluid from the pump interior. The fluid can be a gas and/or a liquid.

In particular, the pump interior fluidically couples the inlet and the outlet to one another. In the present case, a fluidic connection or a fluidic coupling means that a gas and/or a liquid (fluid) can flow between two fluidically coupled elements or between two elements that are fluidically connected.

The pump further includes an impeller. The pump can further comprise a shaft, wherein the impeller can be coupled to the shaft in a rotationally fixed manner. In this case, the impeller can be arranged in particular on the shaft.

The impeller has multiple impeller blades. These are arranged in particular on the radial outside of the shaft (distributed over the circumference of the shaft).

The shaft can drive the impeller. In other words, the shaft can cause the impeller to rotate about the longitudinal axis of the shaft. The shaft can be designed as a hollow shaft. The impeller blades can be at least partially hollow.

The pump is set up in such a way that the impeller is driven, in particular rotationally, and a fluid, for example a coolant, can thereby be conveyed from the inlet (suction connection) to the outlet (pressure connection). In particular, the impeller can be driven by the shaft.

The impeller and/or the impeller blades is/are arranged at least partially inside the pump interior. Additionally or alternatively, the shaft can be arranged at least partially inside the pump interior. In particular, the impeller and the impeller blades can be arranged entirely in the pump interior.

The pump housing has a damping device for reducing a pressure generated locally at the radially outer ends of the impeller blades.

In particular, the radially outer ends of the impeller blades correspond to the ends of the impeller blades facing away from the shaft.

This locally generated pressure occurs during the rotation of the impeller (i.e. during operation of the pump), especially at narrow points between the individual impeller blades and the pump housing. This pressure follows the rotation of the impeller blades.

In other words, when an impeller blade approaches a constriction, the displacement effect causes increased pressure. In other words, a mountain of pressure is built up. If the impeller blade continues to rotate, this pressure peak is reduced again. The pressure peak moves together with the impeller blade. Due to the rotation of the impeller blade, the pressure peak is periodically built up and reduced again at a frequency corresponding to the rotation frequency of the impeller. This creates a pressure pulsation, especially at the constriction. The frequency of this pressure pulsation is proportional to the product of speed and the number of impeller blades (blade repetition frequency).

The distance between the individual impeller blades (or their radially outer ends) results in pressure fluctuations that are transmitted over the pump flange houses can be emitted into the environment as audible sound. The damping device reduces these pressure fluctuations and thus reduces the noise emitted to the environment via the pump housing.

There may be an electric machine (electric motor) coupled to the shaft such that it can be driven to rotate by driving the electric machine. The pump can be designed in particular as an electric coolant pump.

The pump, in particular the pump housing, can have additional components, for example an expansion tank for fluid. It is also conceivable that the pump, in particular the pump housing, can be integrated into an expansion tank for fluid.

According to a development, the pump housing can be a volute housing. In this case, the volute housing can have a tongue, in which case the damping device can be arranged in the tongue.

In particular, the tongue represents the narrowest point between the impeller or the impeller blades and the pump housing. This is where the greatest pressure gradient (pressure peak) can be expected. In particular, the tongue separates the part of the pump interior in which the impeller is arranged from the outlet or outlet channel, which extends radially or tangentially away, in particular with respect to the impeller.

According to a development, the pump can be a centrifugal pump, in particular an electronically commutated centrifugal pump (coolant pump).

According to a development, the damping device can have a first opening, a second opening and a damping chamber. In this case, the first opening can fluidly connect the pump interior and the damping chamber to one another. In this case, the second opening can fluidly connect the damping chamber and the pump interior to one another. In other words, the pump interior can be fluidically connected to the damping chamber by means of the first and the second opening. In particular, the damping chamber can have a (circular) round cross section.

According to a development, the mean cross section of the first opening can be smaller than the mean cross section of the damping chamber. In the present case, the mean cross section means the geometric mean of all cross sections of the first opening or the damping chamber perpendicular to the longitudinal axis of the first opening.

In particular, the cross section of the first opening in a region facing the damping chamber is smaller than the cross section of the damping chamber in a region facing the first opening. In other words, the cross section perpendicular to the longitudinal axis of the first opening in the transition area from the first opening to the damping chamber suddenly becomes larger. The transition between the first opening and the damping chamber can thus function as a first Carnot diffuser. For this purpose, the fluid can be conveyed in a first flow direction through the first opening into the damping chamber by rotating the impeller or the impeller blades in a first direction of rotation.

In particular, the cross section perpendicular to the longitudinal axis of the second opening can suddenly increase at the transition between the second opening and the pump interior, so that this transition can function as a second Carnot diffuser when the fluid is conveyed in the first flow direction.

According to a development, the average cross section of the second opening can be smaller than the average cross section of the damping chamber. In the present case, the mean cross section means the geometric mean of all cross sections of the second opening or of the damping chamber perpendicular to the longitudinal axis of the second opening.

In particular, the cross section of the second opening in a region facing the damping chamber is smaller than the cross section of the damping chamber in a region facing the second opening. In other words, the cross section perpendicular to the longitudinal axis of the second opening suddenly increases in size in the transition area from the second opening to the damping chamber. With this, the transition between the second opening and the damping chamber can function as a third Carnot diffuser. For this purpose, the fluid can be conveyed in a second flow direction through the second opening into the damping chamber by rotating the impeller or the impeller blades in a second direction of rotation.

In particular, the cross section perpendicular to the longitudinal axis of the first opening can suddenly increase at the transition between the first opening and the pump interior, so that this transition can function as a fourth Carnot diffuser when the fluid is conveyed in the second flow direction.

In particular, the first direction of rotation is opposite to the second direction of rotation. In particular, the first direction of flow is opposite to the second direction of flow.

This means that the Carnot effect (in both directions of rotation or both directions of flow) can be used twice. In other words, two Carnot diffusers can be implemented in each flow direction of the fluid.

According to a development, the first opening, the second opening and/or the damping chamber has rounded edges, in particular no sharp edges. In particular, the damping chamber has no sharp edges in the area facing the first and/or second opening. In particular, the first and/or the second opening does not have any sharp edges in the area facing the damping chamber.

According to a development, the impeller blades can be arranged at irregular distances from one another on the impeller. In this way, the noise occurring during operation of the pump (or during the rotation of the impeller or impeller blades) can be distributed over a broader frequency range, as a result of which the audible noise peaks can be reduced. However, it is also conceivable that the impeller blades can be arranged on the impeller at regular intervals from one another.

According to a development, the tongue can have a V-shaped geometry. In other words, the cross section, in particular perpendicular to the axis of rotation of the shaft (ie perpendicular to the axial direction), of the tongue can be essentially V-shaped. The tongue can be rounded at its free end to avoid sharp edges. In other words, the end of the tongue protruding into the interior of the pump can be rounded.

According to the invention, a vehicle, in particular a motor vehicle, is proposed with a pump according to the above statements. With regard to the advantages that can be achieved in this way, reference is made to the relevant statements on the pump. The measures described in connection with the pump can serve to further refine the vehicle.

The vehicle can be designed as an electric motor vehicle.

• 1 eine Schnittdarstellung einer erfindungsgemäßen Pumpe und
• 2 einen vergrößerten Ausschnitt aus 1.

An embodiment of the invention will be explained below with reference to the accompanying drawings. It shows, each schematically,

• 1 a sectional view of a pump according to the invention and
• 2 an enlarged section 1 .

1 shows a schematic representation of a pump 10 for conveying a fluid. The pump 10 has a pump housing 12 with a pump interior 14, an inlet 16 for supplying the fluid into the pump interior 14 and an outlet 18 for discharging the fluid from the pump interior 14.

The pump 10 further has a shaft 20 and an impeller 22 coupled in a torque-proof manner to the shaft 20 . The impeller 22 has a plurality of impeller blades 24 . The impeller 22 can be driven in a first direction of rotation 11 by means of the shaft 20 . In principle it is also conceivable that the shaft 20 can be rotated in a second direction of rotation 13 which is opposite to the first direction of rotation 11 .

In the example, the impeller blades 24 are arranged on the impeller 22 at regular intervals from one another. In the present case, the impeller blades 24 have a shape that is curved in the second direction of rotation 13 . The impeller 22 and the impeller blades 24 are arranged entirely in the pump interior 14 .

In the example, the pump 10 is in the form of a centrifugal pump 34 . The pump housing 12 is designed as a volute housing 30 with a tongue 32 . The tongue 32 is rounded at its end projecting into the pump interior 14 .

A damping device 26 is arranged in tongue 32 . This serves to reduce a pressure locally generated at the outer ends 28 (or the ends facing away from the shaft 20) of the impeller blades 24.

The fluid to be conveyed is sucked in through the inlet 16 and conveyed radially outwards (ie radially outwards from the axis of rotation of the shaft 22) by the rotation of the impeller 22 on the impeller blades 24 . The fluid then exits the pump housing 12 via the outlet 18.

The fluid is accelerated along the impeller blades 24 . This creates a locally increased pressure between the radially outer ends 28 of the impeller blades 24 and the pump housing 12 . This depends, among other things, on the distance between the radially outer ends 28 of the impeller blades and the pump housing 12 . The smaller the distance between the radially outer ends 28 of the impeller blades 24 and the pump housing 12, the higher the locally generated pressure.

The narrowest point between the pump housing 12 and the impeller blades 24 (or the impeller 22) is formed by the tongue 32. This is where the locally generated pressure is greatest. The rotation of the impeller 22 causes pressure fluctuations and, in particular, pressure peaks on the tongue 32, which can lead to an annoying noise. The damping device 26 is arranged in the tongue 32 in order to reduce the pressure peaks.

2 shows an enlarged section 1 . In particular, the tongue 32 and the damping device 26 are shown enlarged.

The damping device 26 has a first opening 36 , a second opening 38 and a damping chamber 40 . The pump interior 14 is fluidically connected to the damping chamber 40 via the two openings 36 , 38 .

If the impeller 22 rotates in the first direction of rotation 11 (cf. 1 ), the fluid flows from the pump interior 14 through the first opening 36 into the damping chamber 40 and from there again through the second opening 38 into the pump interior 14 (first flow direction).

The first and second openings 36, 38 are narrow compared to the damping chamber 40, respectively.

In the present case, the cross section of the first opening 36 is smaller in its region 42 facing the damping chamber 40 than the cross section of the damping chamber 40 in its region 44 facing the first opening 36.

In other words, the cross section perpendicular to the longitudinal axis of the first opening 36 at the transition from the first opening 36 to the damping chamber 40 becomes much larger. This transition thus represents a first Carnot diffuser (in the first flow direction).

From the damping chamber 40, the fluid continues to flow through the second opening 38 into the pump interior 14, where the cross-section widens again significantly. Thus, a second Carnot diffuser (in the first flow direction) is realized.

The fluid is thus accelerated through the first, in particular narrow, opening 36, so that the kinetic energy of the fluid increases. The fluid then enters the damping chamber 40, where the kinetic energy of the fluid is dissipated due to the cross-sectional expansion (first Carnot diffuser). The fluid is then accelerated through the second, in particular narrow, opening 38 so that the kinetic energy of the fluid increases. The fluid then enters the pump chamber 14, where the kinetic energy of the fluid is dissipated due to the widening of the cross section (second Carnot diffuser). In this way, the locally increased pressure can be reduced in two stages (first and second Carnot diffuser).

If the impeller 22 rotates in the second direction of rotation 13 (cf 1 ), which can optionally be provided, the fluid flows from the pump interior 14 through the second opening 38 into the damping chamber 40 and from there again through the first opening 36 into the pump interior 14 (second flow direction).

In the present case, the cross section of the second opening 38 is smaller in its region 46 facing the damping chamber 40 than the cross section of the damping chamber 40 in its region 48 facing the second opening 38. In other words, the cross section perpendicular to the longitudinal axis of the second opening 38 at the transition from the second opening 38 to the damping chamber 40 is greatly increased. This transition thus represents a third Carnot diffuser (in the second flow direction).

From the damping chamber 40, the fluid continues to flow through the first opening 36 into the pump interior 14, where it again becomes strong

Cross-sectional enlargement is coming. Thus, a fourth Carnot diffuser (in the second flow direction) is realized.

The fluid is thus accelerated through the second, in particular narrow, opening 38 so that the kinetic energy of the fluid increases. The fluid then enters the damping chamber 40, where the kinetic energy of the fluid is dissipated due to the cross-sectional expansion (third Carnot diffuser). The fluid is then accelerated through the first, in particular narrow, opening 36 so that the kinetic energy of the fluid increases. The fluid then enters the pump chamber 14, where the kinetic energy of the fluid is dissipated due to the widening of the cross section (fourth Carnot diffuser). In this way, the locally increased pressure can be reduced in two stages (third and fourth Carnot diffuser).

The first opening 36, the second opening 38 and the damping chamber 40 have rounded edges 50 here. For the sake of clarity, in 2 only two edges 50 are provided with a reference number. Here the first opening 36, the second opening 38 and the damping chamber 40 have no sharp edges.

Claims (10)

Pump (10) for a vehicle, in particular a motor vehicle, for conveying a fluid, comprising - a pump housing (12) with a pump interior (14), an inlet (16) for supplying the fluid into the pump interior (14) and an outlet (18) for discharging the fluid from the pump interior (14), - an impeller (22), the impeller (22) having a plurality of impeller blades (24), - the impeller (22) and/or the impeller blades (24) being arranged at least partially inside the pump interior (14), - the pump housing (12) a damping device (26) for reducing a pressure generated locally at the radially outer ends (28) of the impeller blades (24). Pump (10) after claim 1 , characterized in that the pump housing (12) is a spiral housing (30), the spiral housing (30) having a tongue (32), the damping device (26) being arranged in the tongue (32). Pump (10) after claim 1 or 2 , characterized in that the pump (10) is a centrifugal pump (34). Pump (10) according to one of the preceding claims, characterized in that the damping device (26) has a first opening (36), a second opening (38) and a damping chamber (40), the first opening (36) the pump interior ( 14) and the damping chamber (40) fluidly connects to each other, and wherein the second opening (38) fluidly connects the damping chamber (40) and the pump interior (14) to each other. Pump (10) after claim 4 , characterized in that the mean cross section of the first opening (36) is smaller than the mean cross section of the damping chamber (40). Pump (10) after claim 4 or claim 5 , characterized in that the mean cross section of the second opening (38) is smaller than the mean cross section of the damping chamber (40). Pump (10) according to one of the preceding claims, characterized in that the first opening (36), the second opening (38) and/or the damping chamber (40) has rounded edges (50), in particular no sharp edges. Pump (10) according to one of the preceding claims, characterized in that the impeller blades (24) are arranged at irregular distances from one another on the impeller (22). Pump (10) according to one of claims 2 until 8th , characterized in that the tongue (32) essentially has a V-shaped geometry, in particular to the axial direction. Vehicle, in particular motor vehicle, with a pump (10) according to one of the preceding claims.

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