FAN MODULE AND METHOD FOR OPERATING THE SAME

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. § 119, of German Patent Application DE 10 2024 203 346.4, filed Apr. 11, 2024; the prior application is herewith incorporated by reference in its entirety.

FIELD AND BACKGROUND OF THE INVENTION

The invention relates to a fan module and to a method for operating the same.

A motor vehicle typically has a radiator by means of which a coolant in an engine cooling circuit can be cooled. When the motor vehicle has an air conditioning system, the system comprises a condenser by means of which a refrigerant for an air conditioning circuit is cooled.

In order to cool the radiator and/or the condenser, a fan module is used to generate a cooling air flow.

The fan is typically mounted in an engine compartment or in a wheel arch of the vehicle. In particular, if the vehicle is used on dirty roads or off-road, there is a risk of the fan module, the radiator, and/or the condenser becoming dirty. This can disadvantageously lead to reduced cooling performance or even a blockage of the fan wheel of the fan module.

A fan assembly is known from published patent application US 2016/047609 A1 which is designed for automatic cleaning of its heat exchanger or air filter. Cleaning involves temporarily reversing the direction of a fan in the fan assembly to reverse the airflow through the heat exchanger or air filter for the purpose of removing dust, dirt, and other contaminants.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a method and a fan module which overcome a variety of disadvantages associated with the heretofore-known devices and methods of this general type and which provides for an especially suitable method for operating a fan module. In particular, the aim is to enable the removal of contamination from the fan module and/or a heat exchanger that is to be cooled by the same. Furthermore, such a fan module as well as a device with such a fan module and with a heat exchanger are to be specified.

With the above and other objects in view there is provided, in accordance with the invention, a method for operating a fan module, which has a fan wheel and a motor for driving the fan wheel. The method comprises:

• • operating the motor in a cleaning operating mode to remove contamination and thereby operating the motor at a predetermined cleaning speed that is greater than a rated speed of the motor.

The method is used to operate a fan module. The fan module is intended and configured to cool at least one heat exchanger, in particular a radiator and/or a condenser. In particular, the fan module is intended and configured for use in a motor vehicle.

The fan module is also designated as a CFM (cooling fan module).

The fan module comprises a fan wheel. The fan wheel serves to generate an air flow in order to cool the heat exchanger as it rotates. Furthermore, the fan module comprises a motor, expediently an electric motor, for the fan wheel, i.e., for driving the fan wheel in rotation.

According to the method, the motor is operated in a cleaning mode to loosen contamination from the fan wheel and/or heat exchanger, i.e., in order to remove the contamination. In the cleaning operating mode, the motor is operated at a predetermined cleaning speed (cleaning revolutions per minute, cleaning rpm), the cleaning speed being greater than the rated speed of the motor, in particular for and/or when cooling the heat exchanger.

Due to the rotation of the motor and the associated fan wheel at the cleaning speed, and/or when the fan wheel accelerates to the cleaning speed, the fan wheel and/or a fan shroud coupled to the fan wheel vibrates. This is caused particularly by an imbalance of the fan wheel due to contamination and/or design-related factors, such as tolerances. Due to this vibration, and/or due to the comparatively high speed of the fan wheel, dirt and/or water is removed from the fan wheel and/or from the fan shroud, in particular shaken off, or this is at least made easier.

Furthermore, the air flow is stronger due to the comparatively fast rotation of the fan wheel, so that any dirt is carried along and removed from the respective heat exchanger by the air flow.

It is expedient that the direction of rotation of the motor and/or fan wheel be the same during the cleaning operating mode as during cooling of the heat exchanger, i.e., that it be the same as in a cooling operating mode.

The rated speed can and/or is expediently understood to mean the speed of the motor at which the motor delivers the nominal power, in particular the maximum power that is intended for continuous operation.

In particular, in cooling mode—i.e., for cooling the respective heat exchanger—the motor is operated at a speed that is less than or equal to the rated speed.

According to one expedient embodiment, the cleaning speed is between 1.5 times and 10 times, in particular between 1.5 times and 5 times, preferably between 2 times and 4 times, for example 3 times the rated speed.

This effects a comparatively strong vibration of the fan wheel and/or fan shroud and/or a comparatively strong air flow for the respective heat exchanger. The cleaning is therefore comparatively reliable.

The cleaning speed is expediently selected in such a way that damage to the fan module and/or the heat exchanger is avoided.

According to one suitable embodiment, the fan wheel is driven at the cleaning speed for a time period between 1 s (second) and 30 s, in particular between 1 s and 10 s. In other words, the cleaning mode continues for this time period. It is expedient to then terminate the cleaning operating mode and/or reduce the motor speed to a speed that is less than or equal to the rated speed. This time limitation makes it possible to prevent damage to the fan module due to vibration and/or comparatively severe wear of the fan module or to at least reduce the risk of this.

According to an advantageous embodiment of the method, the cleaning operating mode is started when off-road operation of the motor vehicle is terminated.

The cleaning operating mode is started in particular and/or preferably automatically when and/or as soon as a signal representing the termination of off-road operation is received from a control device for the motor. In particular, the cleaning operating mode is started as a result of this signal.

The signal is fed to the control device from a control unit that is external to the fan module or from a sensor, for example.

The fan module and/or the heat exchanger can thus be advantageously cleaned after driving off-road, when the fan module is typically dirtied relatively heavily and/or is relatively likely to become dirty. It is in this way that an especially suitable time for the cleaning operating mode is chosen.

Another aspect of the invention relates to a fan module. It is expedient for this to be operable according to the method in one of the variants described above and/or to be operated according to the method.

The fan module comprises—as described in connection with the method—the fan wheel and a motor, in particular an electric motor, for driving the fan wheel. For this purpose, the fan wheel is coupled in a rotationally fixed manner to the motor.

The fan module expediently further comprises a shroud to which the motor is attached and/or which is provided and configured for attachment to the heat exchanger.

Furthermore, the fan module comprises a control unit for carrying out the method according to any one of the method variants described above. The control unit is, or comprises, the (motor) control unit for the motor.

The control unit is therefore designed to control the motor in such a way that it is operated in a cleaning operating mode at a cleaning speed which is greater than the rated speed.

The rated speed and/or the cleaning speed are expediently stored in a memory of the control unit.

The motor is expediently attached to the fan shroud, which will also be referred to simply as the shroud below. The shroud is also designed to be attached to and/or in the vicinity of the heat exchanger. The shroud comprises a fan wheel recess, i.e., a material recess within the fan shroud, whereby the fan wheel is rotatably held in the fan wheel recess.

The fan wheel recess is limited by a shroud ring in a plane that is oriented perpendicular to the axis of rotation of the fan wheel and/or which is the main plane of extension of the shroud. For example, the shroud ring is formed by an edge of the fan wheel recess. Furthermore, for example, the shroud ring is formed by a wall, in particular a hollow cylindrical wall, extending in a direction parallel to the axis of rotation of the fan wheel.

According to a preferred embodiment, the fan shroud comprises a drain hole for dirt released from the fan wheel. Preferably, the drain hole is arranged at least partially in the shroud ring of the fan shroud. Preferably, the drain hole is arranged radially outside the fan wheel.

The drain hole is preferably continuous in a (radial) direction perpendicular to the axis of rotation. Additionally or alternatively, the drain hole is arranged in the vicinity of the shroud which, in the intended installed state, is arranged at the bottom, i.e., facing toward a substructure.

By virtue of the drain hole and/or the arrangement thereof, it is advantageously easier for dirt to flow away from the fan module and/or to prevent blockage of the fan wheel as a result of protective particles accumulating between the fan wheel and the shroud.

According to one especially suitable embodiment of the fan module, the fan wheel and/or the fan shroud has an additive to increase the smoothness of its surface. In other words, the material, in particular plastic, of the fan wheel and/or the fan shroud comprises this additive. The additive is used to reduce the roughness of the surface of the fan wheel and/or fan shroud.

By virtue of this comparatively smooth surface, the adhesion of dirt to this surface is reduced and/or the dirt is easier to remove.

For example, polyamide and/or polypropylene are used as the (base) material for the fan wheel and/or fan shroud. Silicon dioxide, particularly synthetic, natural, and/or mineral silicon dioxide, is advantageously used as an additive.

Another aspect of the invention relates to a device, particularly for a motor vehicle. The device comprises at least one heat exchanger. For example, the heat exchanger is a radiator for engine cooling of the motor vehicle or a condenser for an air conditioning system of the motor vehicle.

For example, the device comprises both a radiator as a (first) heat exchanger and a condenser as a (second) heat exchanger.

Furthermore, the device comprises a fan module which is embodied in one of the fan module variants described above and/or is operable and/or operated according to any one of the method variants described above.

The fan module is designed and configured to cool the heat exchanger by causing an air flow through and/or onto the heat exchanger.

The fan module is expediently arranged and/or attached to the heat exchanger.

For example, the device is embodied as a so-called CRFM (Condenser/Radiator/Fan Module).

Other features which are considered as characteristic for the invention are set forth in the appended claims.

It should also be noted that all specifications and advantageous modifications described in connection with the general invention apply mutatis mutandis to the fan module and/or to the device and vice versa.

Although the invention is illustrated and described herein as embodied in a fan module and method for operating the same, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic sectional view of a device with a fan module and with heat exchangers cooled by the fan module;

FIG. 2 perspective and schematic view of a fan module whose shroud is formed with a drain hole; and

FIG. 3 shows a flowchart of a method for operating a fan module.

Analogous parts and variables are provided with the same reference symbols throughout the figures.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawing in detail and first, in particular, to FIG. 1 thereof, there is shown a schematic cross section through a device 2 which has a fan module 4 and two heat exchangers to be cooled by means of the fan module 4, namely, a radiator 6 and a condenser 8. According to an alternative which is not shown, the device 2 comprises only the radiator 6 or the condenser 8 as a heat exchanger. The following specifications apply analogously.

The device 2 and/or the fan module 4 thereof is intended and configured for a vehicle, in particular for a motor vehicle.

The fan module 4 comprises a fan wheel 10 with fan wheel blades 12 and with a hub 14 and expediently with a fan wheel outer ring (FIG. 2). Furthermore, the fan module 4 comprises a motor 16, preferably embodied as an electric motor, by means of which the fan wheel 10 can be driven. The fan wheel 10 is connected in a rotationally fixed manner at its hub 14 to the motor 16, in particular to its rotor, so that when the motor 16 is in operation, the fan wheel 10 rotates accordingly. The rotation axis R of the motor 16 is therefore the rotation axis of the fan wheel 10.

The sectional plane according to FIG. 1 runs through the rotation axis R of the electric motor 16 and/or fan wheel 10.

The fan module 4 and the heat exchanger(s) 6, 8 are mounted together and form a module. Here, the fan module 4 is joined at its fan shroud 18 to the heat exchanger and/or heat exchangers. The fan shroud 18 comprises a fan wheel recess 20 in which the fan wheel 10 is arranged. For this purpose, the fan shroud 10 comprises struts 22 by means of which the motor 16 and the fan wheel 10 attached thereto are held in the fan wheel recess 20.

Furthermore, the fan wheel module 4 comprises a control unit 24, embodied particularly as a controller, which controls the motor 16. The control unit 24 is configured to carry out the method described in greater detail in connection with FIG. 3 and/or to control the motor 16 in order to carry out the method and/or to appropriately supply it with current.

As is shown by way of example in FIG. 1, the fan wheel recess 20 of the fan shroud 18 is limited by a shroud ring 26 extending along the rotation axis R (with respect to a direction perpendicular to the rotation axis R).

The fan shroud 18 comprises a drain hole 28 which, according to the example shown here, is arranged in sections in the shroud ring 26 and is continuous in the radial direction, i.e., in a direction perpendicular to the (rotational axis) rotation axis R. According to an alternative not shown in greater detail, the drain hole 28 is additionally or alternatively arranged in a cover portion 30 of the fan shroud 18 covering the respective heat exchanger 6 8 and extending in a plane perpendicular to the rotation axis R. The drain hole 28 arranged in the cover portion 30 is then expediently continuous in a direction parallel to the rotation axis R.

The fan wheel 10 and/or the fan shroud 18 have an additive to increase the smoothness of their surface. The fan wheel 10 and/or the fan shroud 18 is expediently made of a plastic that has been provided with the additive. The resulting reduction in the roughness of the respective surface prevents the adhesion of dirt particles thereto, or the risk thereof is at least reduced. For example, polyamide and/or polypropylene are used as plastics. Silicon dioxide is expediently used as an additive.

FIG. 2 shows an embodiment of the fan module 4 of FIG. 1. Specifications in relation to FIG. 1 with respect to the fan module 4 apply analogously.

The motor 16 is covered by the hub or hub cap 14 and is not visible in the view shown. The controller is not shown in any detail.

FIG. 3 shows a flowchart representing a method for operating a fan module 4, which has a fan wheel 10 and a motor 16 for driving the fan wheel 10. The fan module 4 operated according to this method is, for example, the fan module 4 of the device 2 of FIG. 1 and/or the fan module 4 of FIG. 2.

According to the method, in a first step I, a (start) signal S is received from the control unit 24 to start the cleaning operating mode. For example, if the fan module 4 is a component of a vehicle, the signal S is output by a further (vehicle) control unit (not shown), the signal S being output to the control unit 24 when off-road operation of the motor vehicle is terminated.

Subsequently, in step II, a cleaning operating mode of the electric motor 16 is started. The signal S thus causes the motor 16 to operate in the cleaning operating mode.

Here, i.e., during the cleaning operating mode, the motor 16 is operated at a predetermined cleaning speed UR, the cleaning speed UR being greater than the rated speed UN of the motor 16. The cleaning speed UR and/or the rated speed UN are expediently predetermined and stored in a memory 32 of the control unit 24.

The cleaning speed UR is between 1.5 times and 10 times, in particular between 1.5 times and 5 times, preferably between 2 times and 4 times, for example 3 times the rated speed UN.

The cleaning operating mode is maintained for a time period between 1 s and 30 s, in particular between 1 s and 10 s, for example for 3 seconds. In other words, the cleaning mode will end after this time period. In particular, the motor 16 and thus the fan wheel 10 are driven at the cleaning speed UR only for this time period.

This comparatively high speed results in a vibration of the fan wheel 10 and/or the fan shroud 18 coupled thereto, so that dirt is released from the fan wheel 10 and/or the fan shroud 18. In addition, the fan wheel 10 generates a comparatively strong air flow through the respective heat exchanger 6, 8, so that any dirt that is present there is carried along and/or blown out or sucked out. In summary, the method serves to remove dirt from the fan module 4 and/or heat exchanger 6 and/or 8. The loosened dirt particles can then flow out through the drain hole 28.

In the subsequent third step III, after the cleaning operating mode has been terminated, the motor 16 is operated at a speed which is less than or equal to the rated speed UN. In particular, the motor is operated in a normal mode (cooling mode) for cooling the respective heat exchanger 6, 8.

It will be understood that the invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can also be derived therefrom within the scope of the claims by a person skilled in the art without departing from the subject matter of the invention. In particular, any and all individual features described in connection with the exemplary embodiments and/or in the claims can also be combined with one another in other ways without departing from the subject matter of the invention.

The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:

• • 2 device
  • 4 fan module
  • 6 radiator
  • 8 condenser
  • 10 fan wheel
  • 12 fan blade
  • 14 hub
  • 16 motor
  • 18 fan shroud
  • 20 fan wheel recess
  • 22 strut
  • 24 control unit
  • 26 shroud ring
  • 28 drain hole
  • 30 cover portion
  • 32 memory
  • 34 fan wheel outer ring
  • I Reception of a signal to start the cleaning operating mode
  • II Cleaning of the fan module
  • III Normal operation of the fan module
  • R rotation axis
  • S signal
  • UN rated speed
  • UR cleaning speed