WO2015193170A1 - Pump device - Google Patents

Abstract

Pump device (1) for a motor vehicle comprising a pump, wherein the pump comprises a first flow (2) and a second flow (3), wherein the first flow (2) has a first suction kidney and the second flow (3) has a second suction kidney, wherein the first suction kidney and the second suction kidney can be connected via a suction line (4) to a fluid reservoir (5), wherein the first flow (2) has a first pressure kidney and the second flow (3) has a second pressure kidney, wherein the first pressure kidney is connected via a first pressure line (6) to a low-pressure consumer (7) and the second pressure kidney is connected via a second pressure line (8) to a switchover valve (9), wherein the switchover valve (9) selectively connects the second pressure line (8) to the low-pressure consumer (7) or to a high-pressure consumer (10).

Description

 Pumpyorrichtung

 Field of the invention

The present invention relates to a pump device for a motor vehicle and a method for operating a pump device.

State of the art

Pumps find use in automotive and engine technology in many embodiments. In the field of automotive engineering, pumps, in particular vane pumps, are used to supply hydraulic systems. Such vane pumps generally consist of a rotor with radially movable wings, a lifting ring with a stroke contour that defines the pump chamber, a pressure and side plate and a housing with housing cover. In the pressure and side plate are kidney-shaped recesses, the so-called suction and / or pressure kidneys. Fluid is supplied from a fluid tank to the pump chamber via the suction kidney. Via the pressure kidney, the fluid leaves the pump room. The pressure in the suction kidneys is called the suction pressure and is in the range of the ambient atmospheric pressure (1 bar). The pressure on the pressure kidneys is called the system pressure and represents the pressure required by the consumer. Furthermore, channels are incorporated in the pressure plate and side plate, through which the system pressure can be applied to the lower wing surfaces (undercut groove).

The document WO 03/056180 A1 describes a double-stroke vane-cell pump, the pump having a first pump half and a second pump. half of the pen contains. The first pump half is formed from a first suction region and a first pressure region; the second pump half is formed from a second suction region and a second pressure region. Each pump half has a suction kidney and a pressure kidney. The underwing grooves of the pump are divided in two, and each pump half has one of the two undercut grooves. Due to this construction, both pump halves can be used as two separately available feed pumps. For applications in automotive hydraulic systems, a pump as described above is typically operated by an internal combustion engine. If one uses an electric motor for this, in the case of the two load cases

 - Low pressure consumer, that is high pump speed and low drive torque and

 - High pressure consumer, that is low pump speed and high drive torque

the electric motor can only be operated with good efficiency in one of the two load cases, so that the power required by the overall unit, that is pump and electric motor, is low.

Summary of the invention

It is an object of the invention an improved variant of

To illustrate pump device for motor vehicles with reduced electrical power consumption and a method for operating such a pumping device.

The object is achieved by a pump device for a motor vehicle comprising a pump, wherein the pump has a first flow and a second tide, the first trough having a first suction kidney and the second trough having a second suction kidney, the first suction kidney and the second suction kidney being connectable via a suction line to a fluid reservoir, the first trough having a first pressure kidney and the second teat Tide having a second pressure kidney, wherein the first pressure kidney is connected via a first pressure line to a low pressure consumer and the second pressure kidney is connected via a second pressure line with a changeover valve, wherein the changeover valve, the second pressure line optionally with the low pressure consumer or with a High pressure consumer connects.

The pumping device has a double-flow pump, that is, the pump has two separate pump halves, with one half of the pump being called a trough. In this case, a first tide has a first suction area, a first suction area, a first pressure area, a first trough

Druckniere and a second flood a second Saugniere, a second suction region, a second pressure region, a second pressure kidney, the first and the second flood are independently operable as a feed pump. From the first tide a first pressure line leads directly to a low pressure consumer, from the second tide a second pressure line leads to a changeover valve which connects the second pressure line either to the low pressure consumer or to the high pressure consumer. The pump of the pumping device thus has a first and a second tide, wherein a fluid from a fluid reservoir to the high-pressure consumer or the low-pressure consumer can be conveyed via the second tide independently of the first tide, depending on the circuit of the switching valve. This makes it possible to supply a high-pressure consumer only on the second flood of the pump to a cooling fluid promote, so that a pump drive can be operated with a good efficiency.

Further developments of the invention are specified in the dependent claims, the description and the accompanying drawings.

The low-pressure consumer is connected via the first pressure line directly to the first flood. Thus, the fluid from the fluid reservoir to the low-pressure consumer can be permanently conveyed via the first flow and the first pressure line.

The pump of the pumping device can be operated via an internal combustion engine, but preferably via an electric motor. Preferably, the pump of the pumping device is a gear pump or pendulum slide pump or a vane pump.

In a preferred embodiment of the pump of the pumping device, the second tide is the same size as the first tide of the pump or the second trough smaller than the first tide. If the second tide is smaller than the first tide, the pump room of the second tide is reduced. Thus, when supplying the high pressure consumer, i. when the second tide is connected to the high pressure consumer via the second pressure line and the changeover valve, the speed of the pump is further increased to deliver fluid to the high pressure consumer. This in turn has an advantageous effect on the efficiency of the electric motor and subsequently on the power required by the total unit.

The object of the invention is also achieved by a method for operating the pumping device according to the invention, wherein to switch to a low-pressure region via the changeover valve, the second pressure line is connected to the low-pressure consumer and the second pressure line is connected to the high pressure consumer for switching to a high pressure region via the changeover valve.

The operation of the pumping device according to the invention and thus the promotion of the fluid from the fluid reservoir to the low-pressure consumer always takes place via the first flow and the first pressure line. In a low-pressure operation, the second flood can additionally be used to convey the fluid from the fluid reservoir to the low-pressure consumer - in this case, the second pressure line is connected to the low-pressure consumer via the change-over valve. A promotion of the fluid from the fluid reservoir to the high pressure consumer takes place in a high-pressure operation via the connection of the second pressure line via the switching valve with the high-pressure consumer.

The high-pressure consumer is thus supplied only via the second flood of the pump with the fluid from the fluid reservoir. The low-pressure consumer is permanently supplied with the fluid from the fluid reservoir via the first flood and, by switching over the switching valve and resulting in connecting the second pressure line to the low-pressure consumer, can additionally use the second fluid with the fluid from the fluid reservoir be supplied.

By connecting the second pressure line to the high-pressure consumer via the switching valve, the fluid-conveying pump chamber is reduced in size - only the second flow conveys the fluid from the fluid reservoir to the high-pressure consumer. The reduction the fluid-conveying pumping space causes the torque to drop and the pump speed to be increased to deliver the same amount of fluid from the fluid reservoir over only the second flow. Increasing the speed increases the power consumption of the pump. However, the electric motor can be operated in a better efficiency, so that the power required by the total unit decreases. This makes it possible to use a smaller electric motor and save costs, as well as weight.

The first flood promotes when switching to the high pressure area, that is, when connecting the second flood via the second pressure line and the switching valve with the high-pressure consumer, the fluid from the fluid reservoir with low pressure and thus can without interruption a low-pressure consumer with the Supply fluid from the fluid reservoir.

 This allows the high pressure consumer (e.g., hydraulic clutch) and the low pressure consumer (e.g., lubrication) to be simultaneously supplied with the fluid from the fluid reservoir. The first flood delivers fluid without interruption, that is, independent of the switching of the switching valve, in the low pressure range.

Brief Description of the Drawings The invention will now be described by way of example with reference to the drawings.

Fig. 1 shows a schematic circuit diagram of the pumping device according to the invention Fig. 2 shows a diagram "speed vs. torque "

Detailed description of the invention

FIG. 1 shows a schematic circuit diagram of the pump device 1 according to the invention. The pump device 1 has the pump with the first flow 2 and the second flow 3. The first tide 2 is composed of the first suction kidney, the first suction region, the first pressure region, the first pressure kidney and the first underfloor groove. The second flow 3 is composed of the second suction kidney, the second suction region, the second pressure region, the second pressure kidney and the second underfloor groove. The first flood 2 and the second flood 3 are thus not connected to it and can be operated independently of one another as a delivery pump. For this reason, in FIG. 1 the first flood 2 and the second flood 3 symbolically represented by the single-pump symbols 2 and 3.

About the first Saugniere the first flood 2 of the invention

Pumping device 1 is sucked via a suction line 4, the fluid from the fluid id-reservoir 5 in the first suction region of the first flood 2. In the first pressure range of the first flow 2, the fluid is brought from the fluid reservoir 5 to the pressure required for the low-pressure consumer 7 and fed via the first pressure kidney of the first pressure line 6.

Via the second suction kidney of the second flow 3 of the pump device 1 according to the invention, fluid is sucked from the fluid reservoir 5 into the second suction region of the second flow 3 via a suction line 4. In the second pressure range of the second flow 3, the fluid is removed from the fluid Reservoir 5, depending on the circuit of the changeover valve 9, brought to the pressure required for the low-pressure consumer 7 or high pressure consumer 10 and fed via the second pressure kidney of the second pressure line 8.

From the first tide 2, a first pressure line 6 leads directly to a low-pressure consumer 7, from the second tide 3, a second pressure line 8 leads to a switching valve 9 that the second pressure line 8 either with the low-pressure consumer 7, or with the high pressure - Consumer 10 connects.

The pump device 1 includes a first flow 2 and a second flow 3 via the same time by connecting the high-pressure consumer 10 with the second flow 3 via the second pressure line 8 and the switching valve 9, both the low-pressure consumer 7 with the fluid the

Fluid reservoir 5, as well as the high pressure consumer 10 can be supplied with the fluid from the fluid reservoir 5. The first pressure line 6 is connected to the first flood 2 and promotes, even if the second flood 3 is connected via the second pressure line 8 and the switching valve 9 to the high pressure consumer 10, the fluid from the fluid reservoir 5 with low pressure to the Low pressure consumer 7.

The fluid for the high pressure consumer 10 is thus promoted only from the second tide 3. The low-pressure consumer 7 is permanently supplied with the fluid from the first flood 2 and can be supplied by switching the changeover valve 9 and connecting the second pressure line 8 with the low-pressure consumer 7 in addition to the second flood 2 with the fluid. The pump of the pump device 1 is via an internal combustion engine, but preferably via an electric motor 1 1 operable.

Preferably, the pump of the pumping device 1 is a gear pump or pendulum slide pump or a vane pump.

In a preferred embodiment of the pump of the pumping device 1, the second flow 3 of the pump is the same size as the first flow 2 of the pump, but preferably the second flow 3 is smaller than the first flow 2.

FIG. 2 shows the diagram "Speed Yl Vs. Torque X "and shows the influence of the pump device 1 according to the invention on the load case" low pressure consumer "12 and the load case" high pressure consumer "13. The dashed line shows the course of the motor efficiency Y2 of an exemplary electric motor 1 1.

In the case of using an electric motor 1 1 for operating the pumping device 1, only one of the two load cases "low-pressure consumer" 12 and / or "high pressure consumer" 13 can be operated with a good efficiency of the electric motor 1 1. That is, the load case "low pressure consumer" 12 is operated with a good efficiency of the electric motor 1 1, the load case "high pressure consumer" 13 for the operation of the electric motor 1 1 with good efficiency is a challenge - the electric motor 1 1 here operated in the load case "high pressure consumer" 13 with a poor efficiency and the motor efficiency Y2 is low.

The chain of effects according to the invention in the load case "high pressure consumer" 13 is as follows: by connecting the second flow 3 via the second pressure line 8 and via the changeover valve 9 with the high pressure pressure-reducing device 10 there is a reduction of the fluid-conveying pump space of the second flow 3 - only the second flow 3 of the pump of the pump device 1 is used to deliver the fluid from the fluid reservoir 5 at high pressure via the second pressure line 8 to the high pressure pressure consumer 10 to promote. The reduction of the fluid-conveying pump chamber causes the torque X decreases and the pump of the pumping device 1 must be operated at a higher speed Yl to promote the same flow rate with only the second flood 3. An increase in the rotational speed Yl leads to a less pronounced spreading of the two load cases "low-pressure consumer" 12 and "high-pressure consumer" 13. In FIG. 2, the shift toward a better efficiency of the electric motor 1 1 is illustrated by an arrow in the region of the load case "high pressure consumer" 13.

The diagram in FIG. 2 thus shows that the described increase in the rotational speed Y1 advantageously influences an operation of the pump of the pump device 1 with an electric motor 1 1 - the electric motor 11 operates with higher engine efficiency Y 2.

A reduction of the pump space of the second flood 3 with respect to the first flood 2 also causes the pump in the load case "high pressure consumer" 13 must be operated at a higher speed Yl and thus improve the motor efficiency Y2 of the electric motor 1 1st LIST OF REFERENCE NUMBERS

1 pumping device

 2 first tide

 3 second tide

 4 suction line

 5 fluid reservoir

 6 First pressure line

 7 low-pressure consumers

 8 Second pressure line

 9 changeover valve

 10 high-pressure consumers

 1 1 electric motor

 12 load case "low pressure consumer"

13 Load case "high pressure consumer"

X torque

 Yl speed

 Y2 engine efficiency

Claims

Patent claims 1. Pumping device (1) for a motor vehicle comprising a pump, the pump comprising a first flood (2) and a second flood (3), the first flood (2) a first suction kidney and the second flood (3) has a second suction kidney, the first suction kidney and the second suction kidney via a suction line (4) with a fluid reservoir (5) are connected, the first flow (2) having a first pressure kidney and the second flow (3) having a second pressure kidney, the first pressure kidney being connected to a low-pressure consumer (7) via a first pressure line (6), This means that the second pressure kidney is connected to a changeover valve (9) via a second pressure line (8), the changeover valve (9) connecting the second pressure line (8) either to the low-pressure consumer (7) or to a high-pressure consumer ( 10) connects. Pumping device (1) for a motor vehicle according to claim 1, characterized in that the first pressure kidney is permanently connected to the low-pressure consumer (7) via the first pressure line (6). Pumping device (1) for a motor vehicle according to claim 1 or 2, d a d u r c h g e k e n n z e i c h n e t that the Pumping device (1) comprises an electric motor (11) and the pump can be driven by the electric motor (11). Pumping device (1) for a motor vehicle according to one of the preceding claims, This means that the pump is a gear pump or a pendulum slide pump or a vane pump. Pumping device (1) for a motor vehicle according to one of the preceding claims, This means that the second flood (3) is the same size or smaller than the first flood (2). Method for operating a pump device ( 1 ) according to one of the preceding claims, - in order to switch the pump device (1) into low-pressure operation via the switching valve (9), the second pressure line (8) is connected to the low-pressure consumer (7) and - To switch to high-pressure operation, the second pressure line (8) is connected to the high-pressure consumer via the changeover valve (9). Method according to claim 6, This means that when switching to high-pressure operation, the first pressure kidney goes over the first pressure line (6) with the low pressure consumer (7) remains connected. 8. Method according to claim 6 or 7, This means that the pump is driven by an electric motor (11).