Patent Application
20220356835
The present disclosure relates to an electric coolant pump for a cooling circuit and to a method of operating an electric coolant pump associated with a drive assembly of a motor vehicle.
After a cold start, internal combustion engines initially exhibit reduced efficiency and possibly increased pollutant emissions. The reason for this, apart from other aspects, is the high viscosity of the oils in this operating state, which cannot yet sufficiently reduce the friction between the moving oil-lubricated components. For this reason, the basic aim is to heat up the coolant and the engine or transmission oil quickly. At least for extreme climatic operating conditions, it is necessary to heat up the coolant before the engine is started.
To heat the coolant, heating elements have so far either been inserted into the engine block or integrated into existing hose lines.
From the disclosure of DE 103 25 981 A1, it is further known to insert an electric heating element into a suction line of a mechanical cooling water pump.
WO 2004/011796 A1 shows an electric coolant pump for a cooling circuit of a motor vehicle, which functions as an engine preheater. An electric heating element is arranged in a discharge channel and is flushed by the coolant. This arrangement of the heating element makes the engine preheater particularly compact.
DE 10 2017 011716 A1 describes a method for operating an electric coolant pump and a heating element for preheating a drive train unit in a plug-in hybrid vehicle.
Example embodiments of the present disclosure provide electric coolant pumps each including a heater to preheat the coolant, which can be operated efficiently in a simple and environmentally friendly manner.
An example embodiment of the present disclosure provides an electric coolant pump for a cooling circuit of a motor vehicle including a pump chamber. The electric coolant pump includes a suction line which leads into a suction side of the pump chamber, a discharge channel which leads out of a pressure side of the pump chamber, and an electric motor with a controller. The electric coolant pump includes a heater which includes an electric heating element which projects into the suction line or the discharge channel and can be flushed around by the coolant. The electric heating element includes at least two operating states. In a first electric heating element operating state, the electric heating element can be operated from an external power supply system, and in a second electric heating element operating state, the electric heating element can be operated from an on-board power supply system of the motor vehicle. The controller of the electric motor is configured or programmed such that the electric motor includes at least two electric motor operating states. In a first electric motor operating state, the electric motor can be operated from the external power supply system and in a second electric motor operating state, the electric motor can be operated from the on-board power supply system. The electric coolant pump includes a first electrical connection to connect to the external power supply system and a second electrical connection to connect to the on-board power supply system, the first connection being set up to supply power to the heating element and the electric motor.
The heating element and the electric motor of the pump can be operated in an environmentally friendly manner even without a drive assembly of the motor vehicle, e.g., an internal combustion engine or a drive electric motor in the case of electric vehicles. Since the heater is a portion of the pump, the structure is particularly compact. The external power grid is not required to be an element of the motor vehicle. The power grid can be, for example, a charging station, but also a household power connection. No additional connection is required for the heating element, which makes the design particularly simple.
Preferably, the electric coolant pump includes a transformer to drive the electric motor with AC power from the electrical grid.
Furthermore, a motor vehicle is provided with at least one drive assembly and an electric coolant pump described above, the coolant pump being operable to circulate coolant in a cooling circuit of one of the drive assemblies. In this case, the power supply is preferably an external power supply. Preferably, the electric coolant pump includes a housing which defines a structural element of the drive assembly. The arrangement thus saves installation space.
Preferably, the at least one drive assembly of a motor vehicle includes a drive electric motor and/or an internal combustion engine.
The motor vehicle may include at least one electrical consumer and an electrical coolant pump described above, the coolant pump being structured to circulate coolant in a cooling circuit of the electrical consumer. Such an electrical consumer may be, for example, an LED module of a motor vehicle headlamp, which is preferably operated at a predefined operating temperature.
Furthermore, an electric motor vehicle may include at least one battery pack and an electric coolant pump described above, the coolant pump being structured to circulate coolant in a cooling circuit of the battery pack. The battery pack preferably provides power to a drive electric motor. The efficiency of the battery pack is highly temperature dependent. The electric coolant pump can heat or cool the battery pack so that a desired operating temperature can be maintained.
Preferably, the motor vehicle may include generally internal electrical connections that provide an electrical connection to the first and second electrical connections of the electric coolant pump.
It is preferred if the motor vehicle includes an external electrical connection that can be connected to an external power supply to supply power to the heater. In the event that the motor vehicle is a purely electric car, it is preferred that the external electrical connection is also structured to charge the electric car (battery pack).
In addition, an example embodiment of the present disclosure provides a method to operate an electric coolant pump of a motor vehicle which is assigned to a cooling circuit, the motor vehicle including at least one drive assembly which is temperature-controlled by the cooling circuit, the electric coolant pump including a pump chamber, a suction line which leads into a suction side of the pump chamber, and a discharge channel which leads out of a pressure side of the pump chamber, and an electric motor with a controller. The electric coolant pump also includes a heater including an electric heating element that projects into the suction line or the discharge channel and can be flushed around by a coolant. The heating element includes at least two operating states, a first heating element operating state in which the electric heating element can be operated or is supplied from an external power supply system and in a second heating element operating state in which the electric heating element can be operated or is supplied from an on-board power supply system of the motor vehicle, and the electric motor likewise includes at least two electric motor operating states, a first electric motor operating state in which the electric motor can be operated or is supplied from the external power supply system and in a second electric motor operating state in which the electric motor can be operated or is supplied from the on-board power supply system of the motor vehicle. The electric coolant pump includes a first electrical connection to connect to the external power supply system and a second electrical connection to connect to the on-board power supply system, the first connection being set up to supply power to the heating element and the electric motor.
A procedure according to an example embodiment of the present disclosure includes receiving a signal that the coolant is to be heated, querying an operating state of the drive assembly and/or querying whether the motor vehicle is connected to an external power supply, and, if the drive assembly is not running and/or the motor vehicle is connected to an external power supply, operating the electric heating element and the electric motor in the first heating element operating state and the first electric motor operating state.
Thus, efficient heating of the coolant can take place without the need to run the drive assembly. Both the pump and the heating element are then supplied with power from an external source. This is particularly advantageous for electric cars or hybrid drives, which already have a connection to an external power grid and which is then preferably accessed. The external power grid is preferably not a portion of the motor vehicle. The heating element and the electric motor are thus supplied with power in the first operating state via a connection on the motor vehicle for an external power supply. The power grid can be, for example, a power charging station, an inductive charging station, but also a household power connection.
It is advantageous if the controller of the electric motor is set up to carry out the described process steps. An additional controller can then be dispensed with. The heater is then fully integrated in the pump in terms of control technology. However, it is also possible to use an additional separate controller.
Preferably, the electric motor is operated at a low constant speed.
In the event that the combustion engine is running, the electric motor is preferably operated with direct current from a vehicle's electrical system.
In an advantageous example embodiment, the signal for heating the coolant is generated from a signal for a stationary heating operation, i.e., the heater is a portion of a stationary heating operation when the drive assembly is switched off by operating the pump and the electric heating element.
As previously described, it is preferred if the at least one drive assembly includes a drive electric motor and/or an internal combustion engine. In the event that the motor vehicle is a purely electric car, it is preferred that the external electrical connection is also operable to charge the electric car (battery pack).
The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.
Example embodiments of the present disclosure are described below with reference to the drawings.
A pump chamber 6 is formed in the pump housing 3. A pump element 7 in the form of a pump impeller 8 is non-rotatably arranged on the pump shaft 2, lies in the pump chamber 6 and is surrounded by the pump housing 3. The pump chamber 6 is adapted in shape to the pump element 7. Concentric to the central axis of the pump element 7, a suction line 9 in the form of a feed channel opens into a suction side 10 of the pump chamber. Radial to the center axis 100 of the pump element 7, a pressure line 11 in the form of a discharge channel leads out of a pressure side 12 of the pump chamber 6. A heater 13 is arranged in the suction line 9.
The heater 13 has an electrical heating element 14 and an electrical connection 15, the electrical heating element 14 being connected to the electrical connection 15. The electrical connection 15 is provided for connecting the electrical heating element 14 to an external power supply with alternating current, in particular with 230 volts voltage. The electrical heater 13 is attached to the suction line 9 in such a way that the electrical heating element 14 is surrounded by the coolant in the suction line 9. When electric power is supplied to the electric heating element 14 via the electric connection 15, the electric heating element 14 heats up. The electric heating element 14 heats up the coolant in the suction line 9. The coolant pump 1 is driven by means of the electric motor 4. The pump element 7 rotates and conveys the heated coolant, in particular cooling water, from the suction line 9 into the pump chamber 6 and from the pump chamber 6 to the pressure line 11, where it is fed into the coolant circuit of the drive assembly.
The advantage of this arrangement is the accelerated heating of the coolant when the coolant pump 1 is driven. The existing installation space of the coolant pump 1 is optimally utilized by the electrical heater 13, which has a simple design. By connecting the coolant pump 1 to an external power supply, the power supply can be ensured in an environmentally friendly manner even when the engine is switched off or in cold weather.
In general, it may also be envisaged to use the heater in the discharge channel 11 of the coolant pump 1. In this case, the heated coolant is not drawn in directly by pump 1, but is fed directly into the coolant circuit of the drive assembly.
The electric motor is a brushless DC motor comprising a rotor 21 connected to a motor shaft 16 and rotatably mounted in the motor housing 5. The rotor 21 is provided with permanent magnets. A stator 17 is arranged around the rotor 21, which carries a number of windings on an iron core not shown. When suitably driven, the windings generate a magnetic field which drives the rotor 21 to rotate. The windings are usually wound in three phases and are accordingly provided with three electrical connections, via which the windings are connected to a controller (ECU) 18. The controller 18 is supplied with power from the vehicle electrical system 19 during driving operation.
As shown in
The application range is useful in all water-cooled cars and commercial vehicles and especially in hybrid vehicles, which already have an electrical connection that can be used to power the coolant pump and the heater.
The electric heater 13 and the coolant pump 1 can be supplied with power externally so that efficient preheating of the drive assembly is possible. Cold-start problems with the internal combustion engine, such as increased emissions and increased wear, can be reduced or avoided by preheating the coolant in this way. In addition, warm air can be provided for interior ventilation at the start of driving, which increases driving comfort. It is also conceivable to use the heated coolant for stationary heating in the form of a parking heater.
It may also be envisaged to use the electric coolant pump for temperature control of an electrical load. Many such small, decentralized, electric coolant pumps can be used in a motor vehicle. For example, the coolant may be in thermal contact with an LED module of a motor vehicle headlight. In the event that the coolant is too cold, it can be heated by means of the heater.
In another example embodiment, the electric coolant pump is provided for cooling/heating a battery pack of an electric vehicle.
While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 129 068.6 | Oct 2019 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/076574 | 9/23/2020 | WO |
