DE102007019074A1 - Lamp with cooling - Google Patents

Abstract

The invention relates to a luminaire, in particular a recessed ceiling luminaire, comprising a housing (1), a light source arranged inside the housing, for example at least one LED (2), and a device for generating a gas flow through the housing (1) for cooling the light source (2). The device comprises a pump (3), for example a diaphragm or piston pump. To drive the pump, for example, a Stirling engine (30), an electric motor or a system of magnetic coil and solenoid may be provided. With the arrangement according to the invention, the heat that is generated by the light source (2) during operation of the luminaire can be effectively and at the same time carried away with low noise. When using a Stirling engine (30), the heat of the light source (2) can be advantageously used to drive the Stirling engine (30).

Description

The The present invention relates to a luminaire, in particular a recessed luminaire with a housing, one disposed within the housing Light source and a device for generating a through the casing out Gas stream for cooling the light source.

A Light source of a lamp heated usually when the lamp is in operation, so in general the problem of cooling given the light source or the lamp. Is it for example at the light source around a light emitting diode (LED), so is the light flux generated by the LED under normal conditions all the more smaller, the warmer the LED is. It also reduces in the Usually the life of an LED, if it is not cooled during operation. Generally, there is the problem that LEDs are effectively cooled need to, um at one possible Good performance can be operated.

at Surface or pendant lights with light sources in the form of LEDs is it's known the case form the luminaire as a heat sink, on its surface a convection flow can form, with which the excess heat is dissipated, so that the lamp is cooled in this way.

Farther is known, the LEDs of a lamp with the help of a fan to cool. Due to the high speeds that occur in such fans, however, are bearing noise unavoidable. Even the life of such fans, which are typically a few thousand Hours, is comparatively limited.

in the Case of recessed ceiling luminaires, for example in the form of downlights, However, the problem may occur that no such free convection flow or form air circulation, and although the heat sink of the Light in one - after closed at the top - installation opening in the ceiling is installed.

Of the Invention is based on the object to provide a lamp whose Light source effectively cooled especially in the event that there is no free convection can train.

These Task is according to the invention with the one in the independent Claim mentioned lamp solved. Special designs of the invention are in the dependent claims specified.

According to the invention is a lamp, in particular a recessed ceiling light provided, the a housing, one inside the case arranged light source, and a device for generating a through the housing out Gas stream for cooling having the light source. The device comprises a pump. The gas stream may be, for example, an air stream act. The lamp may also be, for example, a Recessed wall light act.

On this way, with the help of a forced gas or air flow one effective cooling the light source can be achieved, and in particular in the Case that no free convection can form upwards, with which the heat generated by the light source are removed could. This may for example be the case when the luminaire is installed in an opening, which is closed at the top, so for example at a Recessed ceiling luminaire installed in a corresponding ceiling opening is.

One is particularly effective heat dissipation possible, when the gas stream passes through a plane which, when the luminaire is in relation to the Vertical aligned according to the operation is this casing interspersed horizontally while passing through the light source or above the light source runs. For example, in the case of a recessed ceiling luminaire said Plane to be the ceiling plane, ie the plane through which Bottom of the ceiling is determined, which in the installed state the Light surrounds. In this way, so by means of the pump a forced gas flow be generated, with which the heat, which is caused by the operation of the light from the light source and accumulate above the light source, down into the room outside be removed from the lamp.

Advantageous the light source comprises at least one LED.

Advantageous is the pump a positive displacement pump, in particular a piston pump or a diaphragm pump. Compared to a fan can Such pumps are operated so that they slower movements To run. This has the advantage that a quieter operation is possible. Besides, have Such pumps generally have a longer life. Especially advantageous is a diaphragm pump, because it is in this case Compared to a piston pump not to sealing problems between Piston and cylinder can come.

Advantageously, the pump comprises a pumping chamber and an outlet channel for the gas flow, wherein the outlet channel connects the pumping chamber with the space outside the luminaire. With "pump chamber" is the one room in the Pump referred to, in which the compression of the gas takes place, which is caused by the movement of the displacement body of the pump, so for example, the piston or the membrane.

This allows an effective gas flow out the pumping chamber. The outlet channel may end, for example, at an outlet opening, which in a wall of the housing the lamp is arranged so that gas from the exhaust duct in the room outside the light stream can. The outlet opening can in the above-mentioned level, so for example in the be provided ceiling level arranged.

Farther the pump may comprise an inlet channel for the gas flow, the outside space the lamp connects to the pumping chamber. That way, one becomes effective flow allowed into the pumping chamber. For example, the intake passage may begin at an intake port, which in a wall of the housing the luminaire is arranged so that gas from outside the room the lamp can effectively flow into the pumping chamber. The inlet opening can doing so in the above-mentioned level, so for example in the proposed ceiling level be arranged.

Advantageous At the same time, valves are used for control at the inlet channel and at the outlet channel the direction of the gas flow arranged.

A particularly effective gas flow can be generated when the pump continues to have a second pumping chamber includes.

Farther Advantageously, the lamp has an electric motor for driving the Pump on, wherein preferably a device is provided with the rotational movement of the electric motor via a crank drive or an eccentric can be converted into a linear movement.

It can also be advantageously provided that the lamp is a system to drive the pump having a magnetic coil and a solenoid includes. This is advantageous because this compared to a Drive with an electric motor no corresponding rotational movement is required; With such a rotational movement is inevitably wear and increased noise connected. Particularly advantageous is provided that the Coil with a low-frequency alternating voltage, preferably smaller can be operated as 20 Hz. This allows a particularly quiet Business.

It can also be advantageously provided that for controlling the Pump a break contact is provided, which preferably opens when the displacer, so For example, the piston of the pump is in an extreme position. It can also be advantageously provided that for controlling the Pump a piezoelectric actuator, such as a bimorph provided is

Especially Advantageously, a Stirling engine is provided for driving the pump. The light source in this case can thermally with the "hot area" of the Stirling engine be connected. In this way, the light source generated by the light source Heat to Drive the pump can be used. The Stirling engine can continue advantageous to be a flat plate Stirling engine, wherein the light source accordingly thermally connected to the corresponding plate is. This form of Stirling engine already works at comparatively very low temperature differences. There is also a flat plate Stirling engine comparatively simple in construction and in the production and can very small in size and in particular very flat accomplished be, which is advantageous in terms of the size of the lamp is.

The Invention will be described below with reference to exemplary embodiments and with reference closer to the drawings explained. Show it:

1 a sketch of a lamp according to the invention with a driven by a Stirling engine diaphragm pump,

2 a sketch of an embodiment with a piston pump,

3 a sketch of an embodiment with a diaphragm pump,

4 a sketch of an embodiment with two pumping chambers, wherein the pump is driven by an electric motor,

5 a sketch of a pump drive with the aid of a bimetallic control,

6 a sketch of a pump drive by means of a magnetic coil and a submersible magnet, and

7 a sketch to an alternative channel guidance.

1 shows a sketch of a lamp according to the invention. The luminaire may in particular be a recessed ceiling luminaire, which is provided for, in a corresponding installation opening in a ceiling 4 to be installed. The installation opening may, for example, be an opening which is closed at the top, so that in general the problem of the cooling of the Light consists.

You can see a case 1 the lamp and a light source in the form of LEDs 2 that way in the case 1 or are arranged on the underside that they - if the light is aligned according to the operation - emit light in the lower half-space.

Furthermore, the lamp comprises an area that serves as a heat sink 7 can be designated and in which a generally with 3 designated pump is arranged, which is adapted to generate a gas flow - in the example shown, an air flow - which is used to cool the light source or the LEDs 2 serves. The heat sink 7 extends at least partially above the light source 2 , The gas flow is through the housing 1 or through the heat sink 7 guided. With the help of the pump 3 Thus, an air flow can be generated which removes the heat, at least to a considerable extent, when the lamp is operated by the LEDs 2 is produced.

In the in 1 The embodiment shown is the pump 3 a diaphragm pump 3 ' with a membrane 12 , The diaphragm pump 3 ' further comprises a pumping chamber 5 , down from the membrane 12 , laterally from the inner surface of a pump cylinder 6 and up from a pump chamber ceiling 14 is limited. The membrane 12 will move up and down alternately when operating with a mid-range, such as the double-headed arrow 13 in 1 indicated and acts in this way as a displacement of the pump 3 on the in the pump room 5 air present.

Furthermore, one recognizes one in the heat sink 7 arranged inlet channel 9 coming from the room outside the case 1 the lamp - or briefly outside space AR - in the pumping chamber 5 leads, allowing air, from the outside space AR through the inlet duct 9 into the interior of the pumping chamber 5 can flow. At the transition from the outer space AR in the housing 1 is an inlet opening 11 intended.

The sketched example shows the inlet opening 11 in a plane E, which is horizontal when the luminaire is correctly aligned and above the LEDs 2 through the housing 1 or the heat sink 7 runs. For example, the level E may be - as in 1 sketched - to coincide with that plane, which is commonly referred to as DE ceiling plane, ie with the plane passing through the underside of the ceiling 4 is fixed, which surrounds the lamp in the installed state of the lamp.

Furthermore, one recognizes an outlet channel 8th which is the interior of the pumping chamber 5 connects to the outside space AR, so that the gas or the air from the pumping chamber 5 can flow into the outer space AR. At the transition between the outlet channel 8th and the exterior space AR is an outlet opening 10 intended.

By choosing an appropriate dimensioning of the channels 8th . 9 can be taken in a relatively simple way influence on the air flow.

To determine the direction of flow, the pump includes 3 ' furthermore a suction or inlet valve 21 , for example, at the transition between the inlet channel 9 and the pumping chamber 5 can be arranged and an air flow from the outer space AR in the pumping chamber 5 allows, in the opposite direction, however, locks. A pressure or exhaust valve 20 , for example, at the transition from the outlet channel 8th can be provided to the outside space AR, allows an air flow from the pumping chamber 5 in the outer space AR, but locks in the opposite direction.

With the described arrangement, it is possible to form an air flow which passes through the horizontal plane E, in particular penetrated from top to bottom and in this way particularly effective from the LEDs 2 generated heat in the outer space AR can carry away. In the example sketched, therefore, has the heat sink 7 via a from the inlet channel 9 and the outlet channel 8th formed channel system, the air flow from the ceiling level DE upwards into the pumping chamber 5 on the one hand and out of the pumping chamber 5 down over the outlet opening 10 in the outer space AR on the other hand allows.

The Arrangement is also suitable for example for a recessed wall luminaire, and although at a corresponding rotated by 90 ° Orientation. In this case, so with a lamp according to the invention an effective airflow through a vertical plane from the inside the lamp in the outdoor space be effected.

In the in 1 sketched embodiment is to drive the diaphragm pump 3 ' provided a Stirling engine, in the form of a flat plate Stirling engine 30 with a lower flat plate or end plate 31 , which is the "hot area" of the Stirling engine 30 forms and an upper end plate 32 that the "cold area" of the Stirling engine 30 forms.

The light source or the LEDs 2 are thermal with the end plate 31 connected, which forms the hot area. The other end plate 32 is thermal with the heat sink 7 connected.

Between the two plates 31 . 32 is formed a cylindrical working chamber, in which a porous working piston 33 of the Stirling engine 30 can move. The Stirling engine 30 draws its energy from the temperature difference of the two end plates 31 . 32 , About the linear movement of the working piston 33 becomes the displacer, here the membrane 12 the pump 3 emotional. The from the pump 3 generated air flow cools over the heat sink 7 the "cold" plate 32 of the Stirling engine 30 and thus maintains the temperature difference. The operation of a Stirling engine and in particular that of a flat plate Stirling engine is known per se. Therefore, this will not be discussed at this point.

The Using a Stirling engine to drive the pump is advantageous because in this way the existing thermal energy in the system for the Drive the pump can be used. An external energy source, for example, in the form of electric current, this is so not mandatory. A flat plate Stirling engine is particularly suitable because with this type of engine already a comparatively much small temperature difference to the drive is sufficient. There is also a flat plate Stirling engine relatively simple in construction and with relatively few components produced. Furthermore, it is possible make the shape of the engine very flat, what the use in a lamp is particularly advantageous.

According to a variant, instead of a - in 3 sketched separately - diaphragm pump 3 ' a piston pump 3 '' provided as in 2 outlined. Instead of a membrane 12 acts in this case, a piston 15 as a displacement on the pump chamber 5 air present. The up and down movement of the piston 15 is in 2 with a double arrow 16 indicated.

It can therefore be provided that the pump is a piston pump 3 '' is that with a Stirling engine 30 is driven.

Either Diaphragm pumps, as well as piston pumps, are positive displacement pumps. Compared to a fan can be a positive displacement pump be operated so that it runs slower. This is advantageous because due to the high speeds that typically occur during fan operation occur, bearing noise inevitable are. A positive displacement pump So it can generally be quieter become. Furthermore is the average life of a positive displacement pump longer as that of a fan.

A Diaphragm pump provides opposite a piston pump has the advantage that sealing problems of the piston across from the cylinder in which the piston is running, can be avoided.

As in 7 also sketched, according to a variant in the membrane 12 valve flaps 27 be formed, which act as an inlet and outlet valve. Here, therefore, the membrane 12 and the valve technology can be realized in one part. At the in 7 sketched variant is the channel guide on the circumference of the pump cylinder 6 arranged. With reference to the inlet opening 11 and the outlet opening 12 For example, it is generally advantageous if these two openings are clearly spaced, for example substantially on opposite areas on the underside of a recessed ceiling light, to avoid that warmed, emerging from the outlet opening air almost directly through the inlet port to a considerable extent again is retraced.

As in 4 indicated, as an alternative to a Stirling engine for driving the pump, for example, an electric motor 22 be provided. The rotating movement of the electric motor 22 can be set, for example via a crank drive or an eccentric in a linear motion, which then to drive the pump 3 , so for example a diaphragm pump 3 ' or a piston pump 3 '' can be used.

As further exemplarily in 4 sketched, can be provided that the pump 3 also a second pumping chamber 5 ' which has a second inlet valve 21 ' with the inlet channel 9 connected via a second exhaust valve 20 ' with the outlet channel 8th , By such a two-chamber system, the effectiveness of the pump 3 continue to be increased. A corresponding two-chamber system can also be realized in the case of a piston pump.

As in 6 sketched, there is another way to drive the pump 3 in generating the linear motion directly. For example, this can be a system with a magnetic coil 24 and a submersible magnet 26 be provided. The sink 24 is doing with the displacement of the pump 3 in the example shown, so with the membrane 12 , connected. The diving magnet 26 is stuck to the heat sink 7 connected. The sink 24 moves in its longitudinal direction, ie in the example sketched in the vertical direction and thereby includes the heat sink 7 more or less deep. In this way, wear can be further reduced and further reduce noise during operation. Particularly advantageous in terms of noise, it is in this case, if doing the coil 24 is operated with a low-frequency AC voltage, for example, <20 Hz.

At the in 6 shown variant, the pump - as outlined - again two pumping chambers 5 . 5 ' exhibit. Of course, also a variant possible with only one pumping chamber.

Farther may alternatively be provided that the control of the pump also directly, for example, with a breaker contact, that opens, when the displacer, so For example, the piston is in an extreme position. For a return of the displacer can be provided in this case, for example, a spring.

As in 5 Outlined, as another alternative for driving the pump 3 a bimetal 34 serve. It is also possible to use a piezoelectric actuator for this purpose, for example in the form of a bimorph.

According to the invention, therefore, a lamp is provided which is a pump 3 has, wherein the pump in particular a diaphragm pump 3 ' or a piston pump 3 '' can be. The pump may in both cases have one or two pumping chambers. The drive of the pump can be done in different ways. Examples of means that can be used are: Stirling engine, electric motor, system with coil solenoid, breaker contact, bimetal, piezoelectric actuator.

1

casing

2

Light source LED (s)

3

pump

3 '

diaphragm pump

3 ''

piston pump

4

blanket

5

pumping chamber

5 '

second pumping chamber

6

pump cylinder

7

heatsink

8th

exhaust port

9

inlet channel

10

outlet

11

inlet port

12

membrane

13

Move the membrane

14

Pumping chamber ceiling

15

piston

16

Move of the piston

20

outlet valve

20 '

second outlet valve

21

intake valve

21 '

second intake valve

22

electric motor

24

magnetic Kitchen sink

26

solenoid

27

valve flaps

30

Stirling engine

31

lower End plate on the hot Area

32

upper End plate at the cold area

33

working piston of the Stirling engine

34

bimetallic

AR

outer space

DE

ceiling plane

e

level

Claims (15)

Luminaire, in particular recessed ceiling luminaire, comprising - a housing ( 1 ), - one within the housing ( 1 ) arranged light source ( 2 ), and - a device for generating a through the housing ( 1 ) guided gas stream for cooling the light source ( 2 ), characterized in that the device is a pump ( 3 ). Recessed ceiling luminaire according to claim 1, wherein the gas flow passes through a plane (E) which - when the luminaire is aligned with respect to the vertical - the housing ( 1 ) penetrated horizontally and thereby by the light source ( 2 ) or above the light source ( 2 ) runs. Recessed ceiling light according to claim 1 or 2, wherein the light source at least one LED ( 2 ). Recessed ceiling luminaire according to one of the preceding claims, wherein the pump ( 3 ) a positive displacement pump, in particular a piston pump ( 3 ' ) or a membrane pump ( 3 '' ). Recessed ceiling luminaire according to one of the preceding claims, wherein the pump ( 3 ) - a pumping chamber ( 5 ), and - an outlet channel ( 8th ) for the gas flow, wherein the outlet channel ( 8th ) the pumping chamber ( 5 ) connects to the outside space. Recessed ceiling light according to claim 5, wherein the pump ( 3 ) further comprises an inlet channel ( 9 ) for the gas flow, wherein the inlet channel ( 9 ) the outside space with the pumping chamber ( 5 ) connects. Recessed ceiling light according to claim 6, wherein at the inlet channel ( 9 ) and at the outlet channel ( 10 ) Valves ( 20 . 21 ) are arranged to control the direction of gas flow. Recessed ceiling luminaire according to one of claims 5 to 7, wherein the pump ( 3 ) a second pumping chamber ( 5 ' ). Recessed ceiling luminaire according to one of the preceding claims, with an electric motor ( 22 ) for driving the pump ( 3 ), wherein preferably a device is provided, with which the rotating movement of the electric motor ( 22 ) can be converted via a crank drive or an eccentric in a linear movement. Recessed ceiling luminaire according to one of the preceding claims, comprising a system comprising a magnetic coil ( 24 ) and a submersible magnet ( 26 ), to drive the pump ( 3 ). Recessed ceiling light according to claim 10, wherein the coil ( 24 ) can be operated with a low-frequency AC voltage, preferably <20 Hz. Recessed ceiling luminaire according to one of claims 4 to 11, wherein for controlling the pump ( 3 ) a break contact is provided which preferably opens when the displacement body of the pump ( 3 ' ) is in an extreme position. Recessed ceiling luminaire according to one of claims 4 to 12, wherein for controlling the pump ( 3 ) A piezoelectric actuator, such as a bimorph, is provided. Recessed ceiling luminaire according to one of the preceding claims, with a Stirling engine ( 30 ) for driving the pump ( 3 ). Recessed ceiling light according to claim 14, wherein the Stirling engine is a flat plate Stirling engine.