DE102021212907A1 - Conveyor device, liquid tank with such a conveyor device and motor vehicle with such a conveyor device or such a liquid tank - Google Patents

Abstract

The invention relates to a conveyor device (21) with at least one level sensor (24, 25) which has a sensor (244, 254) with three electrical connections (241, 242, 243, 251, 252, 253), the second of the two electrical Connections (242, 252) of the sensor (244, 254) of the at least one fill level indicator (24, 25) is designed as a ground connection (242, 252) and is electrically conductively connected to a ground path (277). The ground path (277) is also electrically conductively connected to at least one component (26) of the conveyor device (11). The invention also relates to a liquid tank (3) with such a delivery device (21) and a motor vehicle (4) with such a delivery device (21) or with such a liquid tank (3).

Description

technical field

The invention relates to a conveying device for conveying liquids according to the preamble of claim 1. The invention also relates to a liquid tank with such a conveying device. In addition, the invention relates to a motor vehicle with such a delivery device or such a liquid tank.

State of the art

Fuel delivery devices are known from the prior art, which have a flange, a mechanically commutated DC motor and at least one level sensor, the level sensor comprising a resistive level sensor that works on the principle of a potentiometer. In this case, two electrical lines are provided for supplying the DC motor with electrical energy and, in the event that only one level sensor is provided, two further electrical lines are provided for supplying the level sensor with electrical energy. In the event that two level sensors are provided, it is known in the prior art to provide a common line, which has a ground potential, for the level sensors of the two level sensors. This means that it is hereby possible to provide only three electrical lines instead of four electrical lines for the two resistive level sensors of the two level transmitters, which function according to the principle of a potentiometer. In this way it is possible to save an electrical line, which is associated with cost advantages.

A particular disadvantage of the devices in the prior art is that if there is no fill level sensor that works on the principle of a potentiometer, but a fill level sensor with a magnetic field sensor is used, the number of electrical connections required increases greatly. The reason for this is that a magnetic field sensor requires at least three electrical connections. The first two electrical connections of the magnetic field sensor are used to supply the magnetic field sensor with electrical energy, in that one of the connections is electrically conductively connected to a positive electrical potential and the other to a ground potential. The third connection serves as the signal output of the magnetic field sensor. As a result, three connections would be required for each filling level sensor with a magnetic field sensor, and in the case of a fuel delivery device with two filling level sensors, correspondingly six connections.

The pamphlet U.S. 2004 007 062 A1 discloses a fuel delivery device with a flange and a level indicator, wherein the level indicator can be supplied with electrical energy by means of two electrical lines. The level sensor works on the principle of a potentiometer. The first of the two electrical lines has a positive electrical potential, while the second of the two electrical lines has a ground potential.

The pamphlet DE 10 2005 062 775 A1 discloses a level sensor with a magnetic field sensor, which is designed as a Hall sensor.

Presentation of the invention, task, solution, advantages

It is the object of the present invention to provide a conveying device which is of inexpensive and simple design. A further object is to provide a liquid tank with such a conveying device. Another object is to provide a motor vehicle with a liquid tank of this type or a delivery device of this type.

The object with regard to the conveying device is solved by a conveying device having the features of claim 1 .

The delivery device according to the invention is a delivery device for delivering liquids with a delivery pump,
an electric motor, by which the feed pump can be driven, and at least one level sensor, which has a capacitive,
magnetic, inductive, electromagnetic, hydrostatic or acoustic sensor with three electrical connections, with two of the electrical connections of the sensor of the at least one level indicator being designed to supply the sensor of the at least one level indicator with electrical energy, the first of the first two electrical connections of the sensor of the at least one fill level indicator is electrically conductively connected to a positive electrical potential, with the second of the first two electrical connections of the sensor of the at least one fill level indicator being designed as a ground connection and being electrically conductively connected to a ground path, with the third electrical connection of the sensor of the at least one level sensor is designed as a signal output. The ground path is electrically conductively connected to at least one component of the conveyor device.

The at least one component is preferably connected by the electrically conductive connection protected from electrostatic discharge along the ground path.

The object according to the invention makes it possible to dispense with an additional ground path for the sensor, since an already existing ground path can be used, which is used, for example, to prevent electrostatic discharge.

An alternative delivery device according to the invention is a delivery device for delivering liquids with a delivery pump,
an electric motor, by which the feed pump can be driven, and
a pressure sensor or a temperature sensor with three electrical connections, two of the electrical connections of the sensor being designed to supply the sensor with electrical energy, the first of the first two electrical connections of the sensor being electrically conductively connected to a positive electrical potential, the second of the first two electrical connections of the sensor is designed as a ground connection and is electrically conductively connected to a ground path, the third electrical connection of the sensor being designed as a signal output. The ground path is electrically conductively connected to at least one component of the conveyor device.

In the alternative conveyor device according to the invention, too, the at least one component is preferably protected from electrostatic discharge by the electrically conductive connection to the ground path.

The alternative conveying device according to the invention preferably has a level indicator. In other words, a filling level sensor is optional in the alternative conveyor device according to the invention. This level sensor preferably comprises a capacitive, magnetic, inductive, electromagnetic, hydrostatic or acoustic sensor with three electrical connections, with two of the electrical connections of the sensor of the at least one level sensor being designed to supply the sensor of the at least one level sensor with electrical energy, the first of the first two electrical connections of the sensor of the at least one level indicator is electrically conductively connected to a positive electrical potential, with the second of the first two electrical connections of the sensor of the at least one level indicator being designed as a ground connection and being electrically conductively connected to a ground path, the third electrical connection of the sensor of the at least one level sensor is designed as a signal output. It is preferably the same ground path to which the pressure or temperature sensor is already connected in an electrically conductive manner.

Unless stated otherwise, all of the following embodiments, configurations and variants relate both to the conveyor device according to the invention and to the alternative conveyor device according to the invention. In other words, the same specification for the pressure sensor and/or the temperature sensor of the alternative embodiment according to the invention is disclosed below at every text passage that refers to the sensor of the at least first level indicator of the conveyor device, unless otherwise stated. If a subsequent text passage refers to the sensor of the second level indicator of the conveyor device according to the invention, this specification is also disclosed to the sensor of the first or only level indicator of the alternative conveyor device according to the invention, unless otherwise stated.

It is particularly advantageous if one, several or all electrical connections are designed as female electrical connections, as male electrical connections, as electrical lines or as electrical contacts, in particular electrical contact points. This enables reliable electrical contacting.

Furthermore, it is advantageous if the at least one component of the conveying device is at least one further component of the conveying device. As a result, electrostatic discharge is reliably prevented, which is of great safety-relevant importance, particularly in the case of fuel delivery devices.

It is also advantageous if the electric motor is a permanently excited synchronous machine. It is particularly advantageous if the permanently excited synchronous machine has three electrical connections, one of three electrical phase currents being able to be electrically conducted to the stator winding via one of the three electrical connections. This makes it possible to use the stator winding to generate an electromagnetic rotating field that can set the rotor in motion. In particular, the permanently excited synchronous machine is designed as an internal rotor.

It is also preferable if the electric motor includes an electric motor housing. In particular, the electric motor housing is made of an electrically conductive material, for example an electrically conductive metal. Alternatively, the electric motor housing is made of an electric conductive plastic formed. It is thus possible to connect the electric motor housing to the ground path in an electrically conductive manner.

In addition, it is advantageous if the feed pump includes a feed pump housing. In particular, the feed pump housing is made of an electrically conductive material, for example an electrically conductive metal. Alternatively, the feed pump housing is made of an electrically conductive plastic. It is thus possible to connect the feed pump housing to the ground path in an electrically conductive manner.

Furthermore, it is advantageous if the feed pump is a side channel pump stage, a peripheral channel pump stage, a spindle pump stage or a gerotor pump stage. This ensures that the flow rate is regulated as precisely as possible.

It is also expedient if the ground path is formed by an electrical line. It is particularly expedient if a component that takes on an additional function forms the ground path or part of the ground path. Such a component is, for example, an electrically conductive compression spring, which presses a surge pot of the conveying device away from the flange in the direction of a liquid tank bottom. This results in a further cost advantage. This configuration is particularly expedient if the delivery device is a fuel delivery device and the liquid tank is a fuel tank.

In general, the at least one level indicator is the first level indicator if an embodiment is specified that has more than one level indicator.

A preferred exemplary embodiment is characterized in that the conveying device has a second fill level indicator, which includes a capacitive, magnetic, inductive, electromagnetic, hydrostatic or acoustic sensor with three electrical connections,
that two of the electrical connections of the sensor of the second level indicator are designed to supply the sensor of the second level indicator with electrical energy, that the first of the two of the electrical connections of the sensor of the second level indicator is electrically conductively connected to a positive electrical potential, that the second of two of the electrical connections of the sensor of the second fill level indicator are designed as ground connections, that the third electrical connection of the sensor of the second fill level indicator is designed as a signal output, and that the ground connection of the sensor of the second fill level indicator is electrically conductively connected to the ground path. Advantageously, in this embodiment, the ground path means the same ground path to which the ground connection of the sensor of the first fill level indicator is already electrically conductively connected.

This makes it possible to save a further ground path for the sensor of the second fill level indicator. This means that an additional ground path does not have to be provided for either the sensor of the first level indicator or the sensor of the second level indicator, which entails significant cost advantages compared to an embodiment with separate ground paths for each of the sensors.

In general, a signal can be output by the signal output of the sensor of the first filling level indicator and by the signal output of the sensor of the second filling level indicator, from which the respective filling level can be evaluated. The signal is, for example, an electrical voltage that is proportional to the respective fill level, or a pulse-width-modulated signal. The same applies to the pressure sensor and/or the temperature sensor in the alternative embodiment according to the invention, whereby pressure signals or temperature signals can be output.

It is also advantageous if the conveying device has an evaluation unit by which the signal that can be output at the respective signal output can be evaluated. The evaluation unit is advantageously coupled to the signal output or the signal outputs in a signal-transmitting manner. It is particularly advantageous if the signal-transmitting coupling is in the form of an electrically conductive connection or an electrically conductive connection for each signal output. It is also preferable if the evaluation unit is integrated into the flange.

A further preferred exemplary embodiment is characterized in that the first electrical connection of the first two electrical connections of the sensor of the first level indicator and the first electrical connection of the first two electrical connections of the sensor of the second level indicator are electrically conductively connected to the same positive electrical potential. In particular, this positive electrical potential has a voltage of 4 to 6 volts and is therefore below the supply voltage of the electric motor, which is preferably 10 to 13 volts.

It is particularly advantageous if both the first electrical connection of the first two connections of the sensor of the first level indicator and the first electrical connection of the first two connections of the sensor of the second Level sensor are connected to an electrical line that has the positive electrical potential. It is also advantageous if this common electrical line, which has the positive electrical potential, is routed through the flange or into the flange. If this line is routed into the flange, it is particularly advantageous if the line is electrically conductively connected there to a control device.

A further preferred exemplary embodiment is characterized in that the ground path is electrically conductively connected to a neutral or negative electrical potential. This ensures that the ground path has a neutral or negative electrical potential.

Another preferred exemplary embodiment is characterized in that the sensor of the first filling level indicator is designed as a magnetic field sensor, a Hall sensor, a magnetoresistive magnetic field sensor or an ultrasonic sensor and/or that the sensor of the second filling level indicator is designed as a magnetic field sensor, a Hall sensor, a magnetoresistive magnetic field sensor or an ultrasonic sensor is. In other words, depending on the embodiment, it is possible for the type of sensor of the first level indicator to be the same as the type of sensor of the second level indicator or to differ from it. The magnetoresistive magnetic field sensor is in particular an AMR sensor, a TMR sensor or a GMR sensor. Alternatively, the sensor is a sensor that works according to the principle of time domain reflectometry. This paragraph, relating to the specification of the sensor of the at least one and/or the second level indicator, is only applicable to the alternative conveyor device according to the invention if it has at least one level indicator with a capacitive, magnetic, inductive, electromagnetic, hydrostatic or acoustic sensor. This paragraph only specifies the level indicator sensor of the alternative inventive embodiment and not the temperature or pressure sensor.

In principle, it is expedient if the at least one level sensor has a float, by means of which, together with a lever arm, a level change can be converted into a rotation or a pivoting movement of a permanent magnet which is fastened to the lever arm. The movement of the permanent magnet, which interacts with the sensor of the at least one level sensor, makes it possible to determine the level using the magnetic field sensor. In particular, in embodiments that have a second level indicator, this also has a float, a lever arm and a permanent magnet, which interact with the magnetic field sensor of the second level indicator as described above for the first level indicator. Of course, this paragraph, which describes the lever arm and the float, only refers to the alternative embodiment according to the invention, if this also has at least one level sensor. This paragraph, relating to the specification of the at least one level sensor or sensors, is only applicable to the alternative conveyor device according to the invention if it has at least one level sensor. This paragraph only specifies the interaction of the level indicator sensor in the alternative inventive embodiment when it includes a level indicator with such a sensor, and not the temperature or pressure sensor.

A further preferred exemplary embodiment is characterized in that the ground path is led through the flange. This makes it possible, when the delivery device is mounted in a liquid tank, to lead the ground path out of the liquid tank and to electrically conductively connect it outside the liquid tank to the body of a motor vehicle or to an electrical connection of a control device. It is also conceivable that the ground path leads into the flange and is electrically conductively connected there to an electrical contact of a control device that is arranged in the flange.

It is particularly advantageous if the evaluation unit is integrated into the control unit. It is also advantageous if the control unit includes power electronics for operating the electric motor.

Another preferred exemplary embodiment is characterized in that the ground connection of the sensor of the at least one fill level indicator and/or the ground connection of the sensor of the second fill level indicator is or are electrically conductively connected to the ground path by means of at least one plug contact. Complex contacting processes are avoided by means of the plug contact and functionally reliable electrical contacting is ensured.

Another preferred exemplary embodiment is characterized in that the at least one component of the delivery device, which is protected from electrostatic discharge by means of the electrically conductive connection to the ground path, is a pump stage of the delivery pump, the delivery pump housing, a pressure control valve, a fuel filter and/or an electrical consumer, in particular the electric motor, a pressure sensor and/or which is a temperature sensor. The at least one component is in particular the feed pump housing or the electric motor housing. It is particularly advantageous if one, two, three, four or all of the above components are electrically conductively connected to the ground path, in other words to the same ground path.

It is also advantageous if the at least one component, multiple components or all components that are electrically conductively connected to the ground path are electrically conductively connected to the ground path directly, indirectly or by means of a plug connection.

A further preferred exemplary embodiment is characterized in that the conveying device has a pressure sensor and/or a temperature sensor which has three or three electrical connections each, one of the connections or one of the three connections each being designed as a ground connection and being electrically conductive with the ground path connected is. Furthermore, it is expedient if the pressure sensor is designed to determine the tank pressure or the delivery pressure of the delivery device. Furthermore, it is expedient if the temperature sensor is designed to determine the temperature of the liquid to be pumped or its vapor. It is particularly expedient if one of the electrical connections of the pressure sensor, together with the ground connection of the pressure sensor, is designed to supply the pressure sensor with electrical energy and is electrically conductively connected to a positive electrical potential. The same applies alternatively or additionally to the temperature sensor. In particular, this electrical connection is electrically conductively connected directly or indirectly to the same positive electrical potential as the sensor of the at least one fill level indicator. Furthermore, it is preferred if the third electrical connection of the pressure sensor is designed as a signal output. The same applies additionally or alternatively to the temperature sensor. This paragraph basically refers to the conveyor device according to the invention.

Another preferred exemplary embodiment is characterized in that the delivery device is configured as an oil delivery device, a reducing agent delivery device for exhaust gas purification, a water delivery device, a coolant delivery device, a cleaning agent device or a fuel delivery device.

The second task is solved by a liquid tank with a conveying device according to the invention. Depending on the design of the delivery device, it is expediently a fuel tank, a water tank, an oil tank, an oil pan, a reducing agent tank or a cleaning agent tank. The liquid tank is preferably a fuel tank which is designed as a saddle tank with a first and a second fuel chamber,
wherein the first level sensor is configured to measure a first level in the first fuel chamber, and the second level sensor is configured to measure a second level in the second fuel chamber. Such a fuel tank has a delivery device, which is designed as a fuel delivery device. It is particularly preferred if the first level indicator is arranged in the first fuel chamber and the second level indicator is arranged in the second fuel chamber.

The third object is achieved by a motor vehicle with a conveyor device according to the invention or a liquid tank according to the invention. The motor vehicle is preferably equipped with an internal combustion engine, which can be supplied with fuel from the fuel tank with the aid of the fuel delivery device.

Advantageous developments of the present invention are described in the dependent claims and in the following description of the figures.

character list

• 1 eine Kraftstofffördervorrichtung aus dem Stand der Technik, und
• 2 ein erfindungsgemäßes Kraftfahrzeug.

The invention is explained in detail below using exemplary embodiments with reference to the drawings. In the drawings show:

• 1 a prior art fuel delivery device, and
• 2 a motor vehicle according to the invention.

Preferred embodiment of the invention

The reference number in the 1 illustrated components of the fuel delivery device from the prior art, is preceded by the number 1, while the reference numerals in the 2 illustrated components of the fuel delivery device according to the invention, in each case the number 2 is placed in front.

The 1 shows a fuel delivery device 11 known from the prior art. The fuel delivery device 11 comprises a flange 12, a mechanically commutated DC motor 13, a first level sensor 14 and a second level sensor 15. The DC motor 13 has an electrical connection 131 which is electrically is connected to a positive electrical potential, and an electrical terminal 132, which is electrically connected to a negative electrical potential. The DC motor 13 is supplied with electrical energy by means of the two electrical connections 131, 132. The first filling level sensor 14 and the second filling level sensor 15 each have a resistive filling level sensor 144, 154 which works according to the principle of a potentiometer. Both the resistive fill level sensor 144 of the first fill level indicator 14 and the resistive fill level sensor 154 of the second fill level indicator 15 each have a ground connection 142,152, which are each electrically conductively connected to a common ground path 14252, which has an electrical ground potential. Furthermore, the two level sensors 144, 154 each have an electrical connection 141, 151 which has a positive electrical potential. The voltage drop across one of the level sensors 144, 154 is proportional to a level change. The voltage drop can be measured using an evaluation unit.

The 2 shows a motor vehicle 4 according to the invention with a fuel tank 3 according to the invention and a fuel delivery device 21 according to the invention. The fuel delivery device 21 has a flange 22 which seals a mounting opening through which the fuel delivery device 21 can be inserted into the fuel tank 3 in a fluid-tight manner, in other words tightly sealed with respect to fuel in liquid form and fuel vapor. The fuel tank 3 is designed as a saddle tank with a first fuel chamber 31 and a second fuel chamber 32 . The fuel delivery device 21 also has a three-phase BLDC motor 23, ie a permanently excited synchronous machine, a first fill level sensor 24 and a second fill level sensor 25. The BLDC motor 23 and the first fuel level sensor 24 are arranged in the first fuel chamber 31 while the second fuel level sensor 25 is arranged in the second fuel chamber 32 . This makes it possible to measure the fill level of the fuel both in the first fuel chamber 31 and in the second fuel chamber 32 independently of one another. The BLDC motor 23 has an electrical connection 231, 232, 233 for one of three electrical phases U, V, W. In other words, the BLDC motor 23 can be supplied with electrical energy by means of the electrical connections 231, 232, 233. Furthermore, the BLDC motor 23 has a ground connection 234 which is electrically conductively connected to a ground path 277 which has a ground potential. The fuel delivery device 21 also has a fuel filter 26 which is also electrically conductively connected to the ground path 277 . The two level sensors 24, 25 each have a magnetic field sensor 244, 254, each of which has a ground connection 242, 252, which are also electrically conductively connected to the ground path 277. Electrical contact is made between ground connections 234, 242, 252 and common ground path 277 by means of an electrical plug connection 271. Electrical contact is also made between fuel filter 26 and ground path 277 by means of electrical plug connection 271. Each of magnetic field sensors 244, 254 also has an electrical Connection 241, 251, which are electrically conductively connected to a common supply path 24151. The supply path 24151 has a positive electrical potential. In addition, both magnetic field sensors 244, 254, which are designed as Hall sensors, each have an electrical connection that is designed as a signal output 243, 253. Electrical signals are output via the signal outputs 243, 253, which are proportional to the respective filling level within the fuel chambers 31, 32 of the fuel tank 3. These electrical signals can be evaluated by an evaluation unit. Such an evaluation unit can be arranged inside the flange 22 or at a distance from the fuel tank 3 and the associated fuel delivery device 21 in the motor vehicle 4 . The flange 22 is made of electrically insulated plastic and has a plurality of electrical conductors 221, 222, 223, 224, 225 226, 227, the electrical connections 231, 232, 233, the common ground path 277, the signal outputs 243, 253 and the Lead the supply path 24151 out of the interior of the fuel tank 3 in a fluid-tight manner through the flange 22 and out of the fuel tank 3 in an electrically conductive manner.

The exemplary embodiments 1 and 2 in particular have no restrictive character and serve to clarify the idea of the invention.

Reference List

11

fuel delivery device

12

flange

13

DC motor

131

electrical connection

132

electrical connection

14

first level sensor

141

electrical connection for positive electrical potential

142

ground connection

144

resistive level sensor

14252

ground path

15

second level sensor

151

electrical connection for positive electrical potential

152

ground connection

154

resistive level sensor

21

fuel delivery device

22

flange

221

electrical conductor

222

electrical conductor

223

electrical conductor

224

electrical conductor

225

electrical conductor

226

electrical conductor

227

electrical conductor

23

BLDC motor

231

electrical connection for phase U

232

electrical connection for phase V

233

electrical connection for phase W

234

ground connection

24

first level sensor

241

electrical connection for positive electrical potential

24151

electrical supply path for positive electrical potential

242

ground connection

243

signal output

244

magnetic field sensor

25

second level sensor

251

electrical connection for positive electrical potential

252

ground connection

253

signal output

254

magnetic field sensor

26

fuel filter

271

electrical connector

3

fuel tank

31

first fuel chamber

32

second fuel chamber

4

motor vehicle

277

ground path

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US2004007062A1 [0004]
• DE 102005062775 A1 [0005]

Claims (13)

Conveying device (21) for conveying liquids, having - a conveying pump, - an electric motor (23) by which the conveying pump can be driven, and - at least one level sensor (24, 25) which has a capacitive, - magnetic, inductive, electromagnetic, hydrostatic or acoustic sensor (244, 254) with three electrical connections (241, 242, 243, 251, 252, 253), wherein the first two of the electrical connections (241, 242, 251, 252) of the sensor (244, 254) of the at least one level indicator (24, 25) are designed to supply the sensor (244, 254) of the at least one level indicator (24, 25) with electrical energy, the first of the first two electrical connections (241, 251) of the sensor (244 , 254) of the at least one level sensor (24, 25) is electrically conductively connected to a positive electrical potential, the second of the first two electrical connections (242, 252) of the sensor (244, 254) of the at least one level sensor (24, 25 ) is designed as a ground connection (242, 252) and is electrically conductively connected to a ground path (277), the third electrical connection (243, 253) of the sensor of the at least one level indicator (24, 25) being used as a signal output (243, 253) is formed, characterized in that the ground path (277) is electrically conductively connected to at least one component (26) of the conveyor device (11). Conveyor (21) after claim 1 , characterized in that the conveyor device (21) has a second level sensor (25) which comprises a capacitive, magnetic, inductive, electromagnetic, hydrostatic or acoustic sensor (254) with three electrical connections (251, 252, 253) that the first two of the electrical connections (251, 252) of the sensor (254) of the second level indicator (25) are designed to supply the sensor (254) of the second level indicator (25) with electrical energy, that the first of the first two electrical connections (251 ) of the sensor (254) of the second level indicator (25) is electrically conductively connected to a positive electrical potential (24151), that the second of the first two electrical connections (252) of the sensor (254) of the second level indicator (25) is used as a ground connection ( 252), that the third electrical connection (253) of the sensor (254) of the second level indicator (25) is designed as a signal output (243), and that the ground connection (252) of the sensor (254) of the second level indicator (25) is electrically conductively connected to the ground path (277). Conveying device (21) according to one of the preceding claims, characterized in that the first electrical connection (241) of the first two electrical connections of the sensor (244) of the first level indicator (24) and the first electrical connection (251) of the first two electrical connections of the sensor (254) of the second level indicator (25) are electrically conductively connected to the same positive electrical potential (24151). Conveying device (21) according to one of the preceding claims, characterized in that the ground path (277) is electrically conductively connected to a neutral or negative electrical potential. Conveying device (21) according to one of the preceding claims, characterized in that the sensor (244) of the first level indicator (24) is designed as a magnetic field sensor, as a Hall sensor, as a magnetoresistive magnetic field sensor or as an ultrasonic sensor and/or that the sensor (254) of the second Filling level sensor (25) is designed as a magnetic field sensor, as a Hall sensor, as a magnetoresistive magnetic field sensor or as an ultrasonic sensor. Conveyor device (21) according to one of the preceding claims, characterized in that the conveyor device has a flange and that the mass path (277) is guided through the flange (22) or into the flange. Conveying device (21) according to one of the preceding claims, characterized in that the ground connection (241) of the sensor (244) of the at least one level indicator (24) and/or the ground connection (251) of the sensor (254) of the second level indicator (25) is electrically conductively connected to the ground path (277) by means of at least one plug contact (271). Conveyor device (21) according to one of the preceding claims, characterized in that the at least one component (26) of the conveyor device, which is protected from electrostatic discharge by means of the electrically conductive connection to the ground path, is a pump stage of the conveyor pump Pressure control valve, a liquid filter (26) and/or an electrical consumer, in particular the electric motor (23), a pressure sensor and/or a temperature sensor. Conveying device (21) according to one of the preceding claims, characterized in that the conveying device has a pressure sensor and/or a temperature sensor which has three electrical connections, one of the connections being designed as a ground connection and being electrically conductively connected to the ground path. Delivery device according to one of the preceding claims, characterized in that the delivery device is designed as an oil delivery device, a reducing agent delivery device for exhaust gas cleaning, a coolant delivery device, a water delivery device, a cleaning agent device or a fuel delivery device. Liquid tank (3) with a fuel delivery device (21). claim 10 , characterized in that the liquid tank (3) is a fuel tank (3) which is designed as a saddle tank with a first and a second fuel chamber (31, 32), that the first level indicator (24) is designed to measure the level in the to measure the first fuel chamber (31), and the second level sensor (25) is designed to measure the level in the second fuel chamber (32). Liquid tank (3) with a conveyor device according to one of Claims 1 until 10 . Motor vehicle (4) with a conveyor device (21) according to one of Claims 1 until 10 or according to a liquid tank (3). claim 11 or 12 .

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