EP4675107A1

EP4675107A1 - A fan arrangement

Info

Publication number: EP4675107A1
Application number: EP24192479.4A
Authority: EP
Inventors: Lijuan Tang; Fu-Lung Lin; Jun Gu
Original assignee: Koninklijke Philips NV
Current assignee: Koninklijke Philips NV
Priority date: 2024-07-01
Filing date: 2024-08-02
Publication date: 2026-01-07

Abstract

A fan arrangement has a rotary fan body (14) having a central web (20) and first and second sets of fan blades (22,24) on opposite sides of the central web (20). A first inlet (40) and a first outlet (42) communicate with the first set of fan blades (22) and a second inlet (44),and a second outlet (46) communicate with the second set of fan blades (24). Thus, the fan arrangement generates two substantially independent airflows, and can thus be used for cooling at least two separate components of a device.

Description

FIELD OF THE INVENTION

This disclosure relates to fan arrangements, for example for cooling components of a device.

BACKGROUND OF THE INVENTION

It is well known to use a fan to cool components which heat up during use. Typically, a fan has an inlet from which ambient air is drawn in and an outlet which is directed towards a component to be cooled. The inlet and outlet are typically fixed and designed taking into account the location of the component to be cooled.
One known fan design is a centrifugal fan comprising a rotating fan body having a hub and a set of fan blades. Air is drawn in axially (i.e., parallel to the axis of rotation of the fan) and expelled tangentially.
Often, there are multiple components that need cooling within a device. It is for example known to divide the tangential outlet from a centrifugal fan into two paths, so that the outlet flow can be delivered to two different components to be cooled. However, this requires the components to be cooled to be located generally at the same location, in order to avoid space-consuming and inefficient flow passageways between the fan and the components.
There is therefore a need for a fan design which can more flexibly provide flows, such as cooling flows, to two (or more) locations and/or to enable greater flexibility in the flow path that can be generated.

SUMMARY OF THE INVENTION

The invention is defined by the claims.
According to examples in accordance with an aspect of the invention, there is provided a fan arrangement comprising:

a fan housing; and
a rotary fan body rotatably mounted in the fan housing and configured to rotate about a rotation axis,
wherein the rotary fan body comprises:
- a central web;
- first and second sets of fan blades, the fan blades extending around the rotation axis and the sets side by side along the rotation axis direction on opposite sides of the central web,
and wherein the fan housing comprises a first inlet and a first outlet for communicating with the first set of fan blades and a second inlet and a second outlet for communicating with the second set of fan blades.

This fan arrangement has a fan body which is divided into two sides by a central web. The central web prevents flow between the two sides (other than leakage around the outside of the fan body) so that the fan body has two (almost) independent sides. By providing a housing with separate inlet-outlet pairs communicating with each side of the fan body, a single fan body and a single fan arrangement can perform two cooling functions. In particular, the outlets can direct air towards different components to be cooled (in the case of air being blown to the component location for cooling) or the inlets can draw air from different components to be cooled (in the case of air being drawn in from the component location for cooling). The central web provides both mechanical strength as well as dividing the fan housing volume into two regions.
The fan housing design enables the inlet and outlet directions to be specified independently for the two flows generated by the fan arrangement.
The rotary fan body for example comprises a centrifugal fan body.
The first inlet is for example on a first side of the fan housing and leads to the first set of fan blades in the rotation axis direction and the first outlet leads tangentially from the first set of fan blades. Thus, the first set of fan blades function as a centrifugal fan on one side of the fan housing.
The second inlet may then be on an opposite, second, side of the fan housing and leads to the second set of fan blades in the rotation axis direction and the second outlet leads tangentially from the second set of fan blades. Thus, the second set of fan blades also function as a centrifugal fan but on the other side of the fan housing.
The first and second inlets may have different areas. This enables a ratio between the two airflows to be set. The first and second inlets may also be located at different positions relative to the fan body (e.g., centrally located or located off center).
The housing for example comprises a cylinder and the fan arrangement further comprises first and second outlet ducts leading from the first and second outlets. The position of the outlets and the outlet ducts can be chosen to match the locations of the components that are to be cooled.
The angular position of one of the outlet ducts around the cylinder may be adjustable. This enables the fan arrangement to be configured for different uses. It may also enable the fan arrangement to cool three or more heat sources. A primary heat source is for example cooled by a fixed outlet duct, and two or more other heat sources are cooled by an adjustable outlet duct. Of course, both outlet ducts may instead be adjustable.
In one set of examples, the first outlet is configured to deliver an airflow to a first heat source and the second outlet is configured to deliver an airflow to a second heat source. Thus, the single fan design can provide separate cooling airflows to two different heat sources.
In another set of examples, the first outlet is configured to deliver an airflow to a first heat source and the second inlet is configured to receive the airflow from the first heat source. In this example, there is a single heat source to be cooled, and a cooling air flow is generated that passes through both sides of the fan body in series. This may be suitable when the airflow needs to follow a convoluted path. The first airflow may lead directly to the first heat source for effective cooling, and the second airflow leads the air away to the outlet.
This disclosure also provides a device comprising:

a first component which generates heat in use;
a second component which generates heat in use; and
the fan arrangement as defined above, wherein the first outlet is configured to deliver an airflow to the first component as a first heat source and the second outlet is configured to deliver an airflow to the second component as a second heat source.
The device for example comprises an IPL device,
wherein the first component comprises one or more selected from the list:
a light source, a reflector, an optical filter, PCB-mounted electrical components, the hot side of a Peltier cooler,
and wherein the second component comprises one or more selected from the list: a light source, a reflector, an optical filter, PCB-mounted electrical components, the hot side of a Peltier cooler,
wherein the first and second components are different.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

Fig. 1 shows in schematic form a fan arrangement 10;
Fig. 2A shows one pair of possible directions for the first and second outlet flows;
Fig. 2B shows that the outlet flows may be at other angles.
Fig. 2C shows that the angular position of one (or both) of the outlet flows may be adjustable;
Fig. 3 shows a first example of an IPL device incorporating the fan arrangement;
Fig. 4 shows the IPL device of Fig. 3 from above to shows the flow paths more clearly;
Fig. 5 shows a second example of an IPL device incorporating the fan arrangement;
Fig. 6 shows the IPL device of Fig. 5 from above to shows the flow paths more clearly.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The invention will be described with reference to the Figures.
It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.
The invention provides a fan arrangement comprising a rotary fan body having a central web and first and second sets of fan blades on opposite sides of the central web. A first inlet and a first outlet communicate with the first set of fan blades and a second inlet and a second outlet communicate with the second set of fan blades. Thus, the fan arrangement generates two substantially independent airflows, and can thus be used for cooling at least two separate components of a device.
When used as a cooling device, it should be noted that the component to be cooled may be located at the inlet side or the outlet side. In other words, a flow may be sucked past the component to be cooled or it may be blown past the component. The examples below show a flow being delivered to a component to be cooled, simply by way of example.
Fig. 1 shows in schematic form a fan arrangement 10 comprising a fan housing 12 and a rotary fan body 14 rotatably mounted in the fan housing and configured to rotate about a rotation axis 16.
The rotary fan body 14 comprises a central web 20, a first set 22 of fan blades 26 and a second set 24 of fan blades 26. The fan blades extend around the rotation axis 16 and are side-by-side (or equivalently back-to-back) along the rotation axis direction on opposite sides of the central web 20.
The fan body may be symmetrical about the central web with the same design of the fan blades, but this is not essential. The fan blades may instead have different designs.
The central web divides the fan housing into two compartments 30, 32. Each compartment functions as an independent fan volume. The central web also provides structural support for the fan blades. The two compartments 30,32 are not perfectly sealed from each other since a gap is needed between the radial outer periphery of the fan body 14 and the inner surface of the housing 12, but they function as essentially independent compartments.
The fan housing 12 comprises a first inlet 40 and a first outlet 42 for communicating with the first set of fan blades 22 in the first compartment 30 and a second inlet 44 and a second outlet 46 for communicating with the second set of fan blades 24 in the second compartment 32.
By providing a housing with separate inlet-outlet pairs communicating with each side of the fan body 14, the single fan body can perform two cooling functions. In particular, in one particular implementation, separate airflows can be generated for different components to be cooled.
Fig. 1 shows with clear arrows the flow into the first inlet 40 and out from the first outlet 42, and shows with shaded arrows the flow into the second inlet 44 and out from the second outlet 46.
The inlet flows are each parallel to the rotation axis 16 and the outlet flows are each tangential, and in a plane perpendicular to the rotation axis.
Fig. 1 shows that the inlet flow to the first inlet 40 centrally aligned with the rotation axis, whereas the inlet flow to the second inlet 44 is offset from the rotation axis. The inlet openings also have different areas. These differences enable different flow rates to be achieved. The inlet and outlet directions, as well as flow rates, can be specified independently for the two flows generated by the fan arrangement.
Fig. 1 shows the housing as a cylindrical body. There will in practice be first and second outlet ducts leading from the first and second outlets to the components to be cooled. The position of the outlets and the paths followed by the outlet ducts can be chosen to match the locations of the components that are to be cooled. There may also be inlet ducts leading from a source of cooling air (e.g. ambient surroundings to a device) to the inlets of the housing 12.
As mentioned above, the components to be cooled may instead be at the inlet sides, in which case there may be ducts between the components to be cooled and the housing inlets. In another arrangement, one side of the fan body may be used to blow cooling air onto a component and the other side of the fan body may be used to suck air from a component.
Fig. 2A shows one pair of possible directions for the first and second outlet flows 50,52 along respective first and second outlet ducts 54, 56. The outlet flows are in opposite directions.
Fig. 2B shows that the outlet flows 50, 52 may be at other angles.
Fig. 2C shows that the angular position of one (or both) of the outlet ducts around the cylinder may be adjustable. This enables the fan arrangement to be configured for different uses.
It may also enable the fan arrangement to cool three or more heat sources. A primary heat source is for example cooled by a fixed outlet duct 54, and two or more other heat sources are cooled by an adjustable outlet duct 56. The movement of the outlet duct can be achieved using a stepper motor or other actuator. The movable outlet duct may also be used for a dynamic (moving) heat source.
Fig. 3 shows an IPL device 60 incorporating the fan arrangement described above.
The IPL device has a flash lamp 62, reflector 64, and optical filter 66, which tougher constitute a light engine. Electrical components 68 include a Peltier cooling system for cooling the skin coupled to a cooling fin 70 (at the hot side of the Peltier cooling system), as well as other PCB-mounted control circuitry.
The IPL device has an outer housing 72 which has air vents to allow the inlet and outlet flows of the fan arrangement to be coupled to the ambient surroundings. Some or all of the components mentioned above are preferably provided with cooling.
By way of example, Fig. 3 shows a first cooling path 80 for the Peltier cooling fin 70 and a second cooling path 82 for the light engine. The second cooling path 82 enters one lateral end of the flash lamp and exits at the opposite end of the flash lamp. This can be seen more clearly in Fig. 4 which shows the IPL device from above.
In the examples above, the first outlet is configured to deliver an airflow to a first heat source (the Peltier cooling fin in the specific example) and the second outlet is configured to deliver an airflow to a second heat source (the light engine in the specific example). Thus, the single fan design can provide separate cooling airflows to two different heat sources.
However, in other examples, the first outlet is configured to deliver an airflow to a first heat source and the second inlet is configured to receive the airflow from the first heat source. In this example, there is a single heat source to be cooled, and a cooling air flow is generated that passes through both sides of the fan body in series. This may be suitable when the airflow needs to follow an angled tortuous path. The first airflow may lead directly to the first heat source for effective cooling, and the second airflow leads the air away to the outlet.
Fig. 5 shows an example of the use of both airflows for a single cooling component, for the IPL device.
The first cooling airflow 80 leads from a first external vent to the light engine, and the second cooling airflow 82 leads from the light engine to a second external vent.
The first and second cooling airflows 80, 82 are shown in Fig. 6 in a view from above.
The airflow between the two vents needs to follow a tortuous path in order to pass by the optical engine, and the use of the two airflows in series facilitates the creation of this path, for example if there are limitations on the placement of the air vents.
The fan arrangement is shown above used in an IPL device. However, it may be used more generally in any device which the use of two airflow paths may be of benefit. For example, the fan arrangement may be used in any device comprising first and second components which generate heat in use, with the first outlet configured to deliver an airflow to the first component and the second outlet configured to deliver an airflow to the second component.
The fan arrangement may also be used when there is only one component to be cooled, but it then gives more flexibility in the creation of a desired path shape.
Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.
The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
If the term "adapted to" is used in the claims or description, it is noted the term "adapted to" is intended to be equivalent to the term "configured to". If the term "arrangement" is used in the claims or description, it is noted the term "arrangement" is intended to be equivalent to the term "system", and vice versa.
Any reference signs in the claims should not be construed as limiting the scope.

Claims

A fan arrangement comprising:
a fan housing (12); and

a rotary fan body (14) rotatably mounted in the fan housing and configured to rotate about a rotation axis (16),

wherein the rotary fan body (14) comprises:
a central web (20);

first and second sets (22,24) of fan blades (26), the fan blades extending around the rotation axis (16) and the sets side by side along the rotation axis direction on opposite sides of the central web (20),

and wherein the fan housing (12) comprises a first inlet (40) and a first outlet (42) for communicating with the first set of fan blades and a second inlet (44) and a second outlet (46) for communicating with the second set of fan blades.
The fan arrangement of claim 1, wherein the rotary fan body (14) comprises a centrifugal fan body.
The fan arrangement of claim 2, wherein the first inlet (40) is on a first side of the fan housing (12) and leads to the first set of fan blades in the rotation axis direction and the first outlet (42) leads tangentially from the first set of fan blades.
The fan arrangement of claim 3, wherein the second inlet (44) is on an opposite, second, side of the fan housing (12) and leads to the second set of fan blades in the rotation axis direction and the second outlet (46) leads tangentially from the second set of fan blades.
The fan arrangement of any one of claims 1 to 4, wherein the first and second inlets have different areas.
The fan arrangement of any one of claims 1 to 5, wherein the housing (12) comprises a cylinder and the fan arrangement further comprises first and second outlet ducts (54, 56) leading from the first and second outlets.
The fan arrangement of claim 6, wherein the angular position of one of the outlet ducts (54, 56) around the cylinder is adjustable.
The fan arrangement of any one of claims 1 to 7, wherein the first outlet (42) is configured to deliver an airflow to a first heat source and the second outlet (46) is configured to deliver an airflow to a second heat source.
The fan arrangement of any one of claims 1 to 7, wherein the first outlet (42) is configured to deliver an airflow to a first heat source and the second inlet (44) is configured to receive the airflow from the first heat source.
A device comprising:
a first component which generates heat in use;

a second component which generates heat in use; and

the fan arrangement of any one of claims 1 to 8, wherein the first outlet is configured to deliver an airflow to the first component as a first heat source and the second outlet is configured to deliver an airflow to the second component as a second heat source.
The device of claim 10 comprising an IPL device (60),
wherein the first component comprises one or more selected from the list:
a light source (62), a reflector (64), an optical filter (66), PCB-mounted electrical components (68), the hot side (70) of a Peltier cooler,

and wherein the second component comprises one or more selected from the list: a light source (62), a reflector (64), an optical filter (66), PCB-mounted electrical components (68), the hot side (70) of a Peltier cooler,

wherein the first and second components are different.