EP1566547B1 - Fluid coupling for vehicle fan - Google Patents

Description

The present invention relates to a fan with a fluid friction clutch for a motor vehicle ventilator.

Such fluid friction clutches are known in the art and are used for radiator fans or as drives for such to allow sufficient heat dissipation of the thermal energy generated by, for example, a fuel engine. Such fan clutches are particularly used for medium power vehicles such as vans, off-road vehicles, light trucks and agricultural applications.

In addition to electrically controlled fan clutches also bimetallic driven clutches are used, which have only secondary storage rooms, especially when using liquid friction clutches. However, this embodiment has control problems at low speed and a rapid connection of the clutch or its start-up characteristic. This is especially true for vehicles with gasoline rotors disadvantageous in which the ratio between rated speed and idle speed of the rotor assumes relatively large values.

Furthermore, so-called "fan boom" or "morning sickness" problems are known. These are particularly caused by the fact that the transmission range of the clutch at engine idle (fan boom) or when the engine is shut down (morning sickness) is relatively heavily filled with oil and the fan as a result of higher engine speeds and the associated venting clutch an unnecessary and / or causes unpleasant air noise.

The object of the present invention is to improve the fan coupling known in the prior art and in particular to enable a more cost-effective production of such a coupling.

The vehicle fan according to the invention has at least one rotatably mounted shaft on which at least one rotationally fixed drive body and at least one rotatably mounted output body is arranged. Between the drive and driven body, a coupling region is provided, which receives a viscous fluid and thereby is able to transmit a torque between the drive body and the output body. The fan is characterized in that the fan, in particular the fan blades of the fan are connected by means of a fastening element with the outer region of the driven body, wherein the fastening element is at least partially plastic coated, wherein the screwing diameter of the fastening element is arranged as a fan hub radially outside of the drive body, said in the connecting region of the fastening element, the plastic casing is recessed at least for the connecting screws and their passage openings.

As a drive body of the fan according to the invention are understood according to the present invention at least partially profiled discs, which are rotatably or non-rotatably mounted on a shaft and are used to transmit a predetermined torque.

As the output body are also at least partially profiled discs understood that cooperate with at least one drive body in the way that directly or indirectly, a predetermined torque is transmitted from the drive body to the output body.

As a fastening ring according to the present invention, in particular, a metal ring is understood, which is connected to at least one predetermined area of the driven body and is arranged in a predetermined area on the fans or in the region of the fan blades.

The attachment ring is preferably made of metallic materials but may also be made of a plastic or composite material such as plastic, carbon fiber composites and the like according to a particularly preferred embodiment.

According to a particularly preferred embodiment, the fluid friction clutch has at least one first and at least one second flow path, which connect at least one fluid reservoir to at least one coupling region. Furthermore, at least one controllable device is provided with which at least one flow path, but in particular the flow paths are opened and closed.

As flow paths are understood in accordance with the present invention, areas of the fluid friction clutch, which are at least partially flowed through by the viscous fluid.

According to a further particularly preferred embodiment, at least one flow path extends in the radial direction as far as within the Drive body that the mouth of the flow path above the fluid level opens in the fluid reservoir of the fluid friction clutch. As flight idvorratsraum is understood according to a particularly preferred embodiment of the space within the fluid friction clutch, which is located radially within the flow path, which is provided for the influx of the viscous fluid in the coupling region, and in the axial direction by at least the drive and / or output body and is clamped in the housing of the fluid friction clutch.

According to a further particularly preferred embodiment, the hub of the fan is formed by the at least partially plastic-coated mounting ring.

A plastic casing according to the present invention is understood to mean a coating selected from a group of materials comprising paints, natural or synthetic plastics, resins, combinations thereof, and the like.

According to a particularly preferred embodiment, the fastening ring has openings which are arranged at a predetermined radius with respect to the axis of rotation. According to a further particularly preferred embodiment, these openings have no plastic coating in a predetermined area and in the openings themselves, wherein it is not precluded to apply a corrosion protection layer in these areas.

According to a preferred embodiment, the fluid friction clutch has a central connection accessible from the front side.

As the front side is understood according to the present invention, the side of the fluid friction clutch, for example, by the air flow of the fan or streamed through the wind of a motor vehicle, in particular is flowed frontal. This can be, for example, the front that belongs to. a radiator of the vehicle is aligned.

According to a further particularly preferred embodiment, fins, in particular cooling fins, are arranged on the side of the output body facing the front. These extend according to a particularly preferred embodiment of the radially outer regions of the drive body radially inwardly, wherein in particular in the embodiment with a central connection of the region of the central connection itself is recessed. The same applies to the areas of the fastening ring, with which it is connected to the output body.

According to a preferred embodiment, the fluid friction clutch is characterized in that the fastening ring is connected to the driven body by a connection type which is selected from a group of connection types, which force, form and / or material connections, such as Rauverbindungen, rivet joints, adhesive bonds , Soldering, welding, combinations thereof and the like.

According to a further preferred embodiment, the fluid friction clutch is arranged in the axial extension of a drive device of a motor vehicle, such as a water pump of a motor vehicle. This can be both a solid compound, as well as a detachable connection, as z. B. by a central connection which extends in the axial direction in the Rotationsvirelle.

The support of the output body is carried out according to a further particularly preferred embodiment by means of a driven-side bearing of Fluid friction clutch and another bearing that is assigned to the drive device.

According to a further particularly preferred embodiment, the fluid friction clutch has controllable devices for the flow paths which, according to a particularly preferred embodiment, are controllable rocker arms, which can preferably be changed in their position by means of an electromagnetic actuator.

The electromagnetic actuator has, for example, magnetic coils which, according to a particularly preferred embodiment, are arranged in the region of the bearings of the rotating axes and / or directly in the region of the housing of the drive device.

The magnetic flux of the electromagnetic actuator is effected according to a particularly preferred embodiment, at least via a ferromagnetic hub and / or axis of the coupling, for example, of an adjacent component. Furthermore, the magnetic flux is effected via at least one ferromagnetic component, which is preferably a sleeve inserted in a non-ferromagnetic pulley, which itself is made of ferromagnetic material. The aim of this arrangement is to build a closed ring of the magnetic field, over which the controllable devices or the controllable device, such as a rocker arm, can be reliably controlled.

According to a further particularly preferred embodiment, however, the electromagnetic actuator can also be arranged on the front side of the coupling.

According to a further particularly preferred embodiment, the coupling region of the fluid friction clutch for transmitting a torque substantially on profile structures, which are arranged concentrically on at least one side of the output and drive body and engage with a predetermined distance.

The invention also includes an apparatus for operating a ventilation system, in particular for a motor vehicle, which has at least one fan, a drive unit, a connecting element and at least one fluid friction clutch according to the present invention. The use of a fluid friction clutch according to the invention for operating a ventilation system for a motor vehicle is also within the meaning of the present invention.

The invention will be explained below with reference to various embodiments. It is to be understood, however, that the illustrated embodiments are not intended to diminish the scope of the invention, but rather to exemplify embodiments which, among other things, are commensurate with the scope of the present invention.

Fig. 1a

eine Querschnittdarstellung einer erfindungsgemäßen Flüssigkeitsreibkupplung;

Fig. 1b

eine Querschnittsdarstellung des Antriebs nach Fig. 1a und einem Lüfterrad;

Fig. 1c

Draufsicht auf den Antrieb und das Lüfterrad nach Fig. 1 b;

Fig. 2

eine geschnittene perspektivische Darstellung eines Antriebskörpers mit Steuereinrichtung;

Fig. 3

eine alternative Ausführungsform einer Flüssigkeitsreibkupplung im Querschnitt;

Fig. 4

eine weitere alternative Ausführungsform einer erfindungsgemäßen Flüssigkeitsreibkupplung in Kombination mit Teilen einer Wasserpumpe;

Fig. 5

einen Querschnitt durch eine weitere alternative Ausführungsform einer erfindungsgemäßen Flüssigkeitsreibkupplung;

Fig. 6

eine geschnittene perspektivische Darstellung eines zweiseitigen profilierten Antriebskörpers mit Steuereinrichtung gemäß der Flüssigkeitsreibkupplung aus Fig. 5.

So shows:

Fig. 1a

a cross-sectional view of a fluid friction clutch according to the invention;

Fig. 1b

a cross-sectional view of the drive to Fig. 1a and a fan wheel;

Fig. 1c

Top view of the drive and the fan after Fig. 1 b;

Fig. 2

a sectional perspective view of a drive body with control device;

Fig. 3

an alternative embodiment of a fluid friction clutch in cross section;

Fig. 4

a further alternative embodiment of a fluid friction clutch according to the invention in combination with parts of a water pump;

Fig. 5

a cross section through a further alternative embodiment of a fluid friction clutch according to the invention;

Fig. 6

a sectional perspective view of a two-sided profiled drive body with control device according to the fluid friction clutch Fig. 5 ,

Fig. 1a shows a fluid friction clutch according to the invention in a cross-sectional view. On the shaft 15, a drive body 2 is rotatably disposed, on the outer regions of a profile 4 is attached. This profile engages in a correspondingly offset profile of the output body 3, which is rotatably mounted on the shaft by means of the bearing 9. The drive body 2 also has a flow path 13, which extends radially from the reservoir 12 in the direction of the radial termination of the output body 3 and is in fluid communication with the coupling region between the profiles of the drive body 2 and the output body 3. According to the embodiment shown here, this flow path serves to supply the viscous fluid into the coupling region. Adjacent to the flow path 13 is located in the storage space 12, in which inter alia, a rocker arm 10 is received, which opens or closes the opening of the flow path 13 in dependence of its parking position.

Furthermore, an actuator 11 is shown, which has a coil according to the embodiment shown here, which can build up a magnetic field via electrical lines.

With the output body 3, a ring 6 is connected via a fastening screw 8, which represents a fastening device for the fan blades 5. In the area of the fastening screw 8, the plastic sheath 7 is reduced such that the fastening ring 6 largely flat on the output body 3 up or rests and can be connected by means of fastening screws 8 with the output body 3. Preferably, the plastic sheath consists of the same material from which the fan blades 5 are made.

In the Fig. 1 a is shown a fastening screw, wherein it is within the meaning of the present invention to use a plurality of fastening screws.

The division of the individual elements of the fluid coupling shown here can, inter alia, achieve a very rapid return of the oil from the coupling region into the reservoir 17, as a result of which the negative phenomena known in the prior art, such as the so-called "fan boom" and "morning sickness "can be avoided or at least reduced. Thus, in particular by the controllable reflux of the viscous fluid via a flow path, the effect of the return pump (not shown) can be greatly increased, whereby a rapid emptying of the coupling region is made possible.

The function and execution of such a coupling is in the DE 102 38 739.7 and is incorporated by reference in the present invention.

To further improve this function of the clutch, the reservoir 12 should be designed with the largest possible diameter so that the centrifugal force-dependent back pressure of the return pump remains as low as possible. This large diameter of the storage space 12 can be achieved for example by the one-sided waiver of the drive body profiling (4). Furthermore, this results in the possibility that can be resorted to a forming technology cheaper producible rear housing cover 14.

Fig. 1b and 1c show the drive Fig. 1a with an impeller in a cross section and top view.

Here, the fan ring 37, the fan screw 36, the fasteners 8 and the cooling fins of the fan hub 35 is shown. Furthermore, the partially plastic-coated fastening device 6 can be seen, which is a fixing ring with predetermined recesses according to the embodiment shown here.

The reference numeral 15, the axis of rotation or shaft of the drive is marked.

Fig. 2 shows a sectional perspective view of the drive body 2 with a control device Fig. 1 a. Here, in addition to the drive body 2 and its profiling 4, the flow path 13, the return opening 20 of another flow path, the storage space 23 and the valve lever 24 can be seen. On the valve lever, a magnet armature 22 is provided which serves in particular for transmitting the actuating force from the actuator to the valve lever.

To avoid an undesirable increase in the idle speed of the fan with the clutch disengaged, the return bore 20 so far be extended to the inside, that the mouth above the liquid level in the reservoir 23 is located. This is particularly important when very high drive speeds are required, since in these cases the pressure on the fluid can dominate the starting pressure of the pump due to the centrifugal force in the return flow bore 21. This can lead to the clutch partially being switched on unintentionally.

In order to further improve the heat dissipation of the fluid friction clutch, the aim is to provide the largest possible diameter of the front side. As a result, the front side housing half of the fluid friction clutch can be effectively equipped with cooling fins. On the other hand speaks against a too large fan hub as uniform as possible flow through the radiator network of a motor vehicle with cooling air, which would not be possible with a large-sized hub diameter in the area lying here.

For this reason, according to the exemplary embodiment illustrated here, the screwed area of the fan hub is set to a relatively large diameter, the plastic casing being cut out at least for the fastening screws and their passage openings in the connecting area. In addition to the improved heat transfer, the larger diameter of the screw leads to a reduction of the mechanical stresses, due to the larger lever arm of the force introduction at the mounting area of the fan.

Fig. 3 shows an alternative embodiment of a fluid friction clutch according to the invention in cross section, in which in particular a front access from the central screw 34 is provided.

Fig. 4 shows an alternative embodiment of a fluid friction clutch according to the invention in combination with a water pump or parts hereof. In this embodiment, the centrally bolted coupling is mounted on a water pump in such a way that the shaft 15 are rotatably connected by means of the central attachment 34 both for the water pump and for the fluid friction clutch.

It should be noted, however, that it is also within the meaning of the present invention to use a different type of connection for the shaft of the water pump and the centrifugal clutch, as for example by means of a one-piece shaft or an intermediate gear.

The drive according to this alternative embodiment via pulley 30 which is rotatably connected to the shaft 15. The actuator 11 for the actuation of the rocker arm 10 is according to this embodiment does not have a ball bearing of the rotating shaft, but is mounted on the housing of the water pump 32. The magnetic flux is conducted via the steel hub of the pulley 30 to the armature 37 and causes the change in position of the rocker arm 10 when current flows through the actuator 11 via the control lines 36. The magnetic reflux takes place via the inserted into the pulley steel sleeve 31, wherein according to a particularly preferred Embodiment, the pulley in this case of a non-ferromagnetic, d. H. non-magnetically conductive material, such as aluminum or alloys thereof and / or the like is produced.

Another advantage of this alternative embodiment is that the number of bearings required to operate the water pump and the fluid friction clutch can be reduced, so that, as in Fig. 4 shown, only two bearings 9 sufficient for fastening the components.

As already shown in the other figures, in Fig. 4 to recognize the fan blades 5, the cooling fins 35, the fastening screw 8 and the metal ring 6.

The Fig. 5 and 6 show further alternative embodiments of the fluid friction clutch according to the invention, in which compared to the previously described fluid friction clutches of the actuator is mounted on the front side of the clutch.

In Fig. 5 is a cross-sectional view of the outer housing of the actuator 11 and the control lines 36 can be seen. About the recesses in the center of rotation of the cooling fins 35, the actuator is in operative connection with the rocker arm 10 of the fluid friction clutch.

The housing 14 closes off the fluid friction clutch toward the front, at least in a liquid-tight manner, wherein, according to the exemplary embodiment illustrated here, the drive body has a profiled section as a coupling region on both side surfaces, which engages in correspondingly designed profiles of the output body 27. It can be seen the flow path 13 and the reservoir 12 for the viscous fluid. The driven pulley 27 is further supported on the shaft 15 via the bearing 9.

Fig. 6 shows a section of the fluid friction clutch Fig. 5 in which a perspective cut representation of the drive body including the actuator 11 and its connection means 36 is shown. Evident are the profiled portions of the drive body 28, wherein further the valve lever 24 is shown for opening and closing the flow paths and its arrangement with respect to the actuator.

Claims (20)

1. A fan having a fluid friction clutch, with a rotatably mounted shaft (15), a drive element (2) mounted on the shaft in a torque-proof manner, a driven element (3) rotatably mounted on the shaft and a coupling region arranged between the drive and driven element and accommodating a viscous fluid, wherein the fan, in particular its fan blades (5), are connected to the outer region of the driven element (3) by means of a fixing element (6), characterised in that the fixing element is at least partly encapsulated in a plastic material, wherein the diameter of the screw connection of the fixing element is arranged as a fan hub radially outside the drive element (2), wherein the plastic encapsulation is recessed in the connecting region of the fixing element at least for the connecting screws and their through-holes.
2. The fan according to claim 1, characterised in that the fixing element is at least one ring segment and/or one structured ring and/or one ring with predefined recesses.
3. The fan according to at least one of the preceding claims, characterised in that at least one first and at least one second flow path for connecting a fluid storage chamber (12) to the coupling region are provided and at least one control device (10) for the flow paths, with which the flow paths are opened and closed, is provided.
4. The fan according to at least one of the preceding claims, characterised in that at least one flow path extends in the radial direction within the drive element to such an extent that the flow path opens into the fluid storage chamber (12) above the fluid level.
5. The fan according to at least one of the preceding claims, characterised in that the hub of the fan is formed by the fixing ring (6) at least partly encapsulated in a plastic material.
6. The fan according to at least one of the preceding claims, characterised in that the fixing ring has openings arranged on a predefined radius with respect to the axis of rotation.
7. The fan according to at least claim 5, characterised in that no plastic encapsulation (7) is provided in the openings and in a predefined area around the opening.
8. The fan according to at least one of the preceding claims, characterised in that the fluid friction clutch has a central connection (34) accessible from the front side.
9. The fan according to at least one of the preceding claims, characterised in that the fixing ring (6) is connected to the driven element (3) by a type of connection which is selected from a group of types of connections having force-fitting, form-fitting and/or material connections, such as screw connections, riveted connections, adhesive connections, soldered or welded connections, combinations thereof and the like.
10. The fan according to at least one of the preceding claims, characterised in that ribs, in particular cooling ribs (35), are arranged on the side of the driven element facing toward the front.
11. The fan according to at least one of the preceding claims, characterised in that the clutch is arranged as an axial extension of a drive device, in particular a water pump of a motor vehicle.
12. The fan according to at least claim 11, characterised in that the clutch is supported in a rotationally movable manner by means of an output drive-side bearing (9) of the fluid friction clutch and a bearing of the drive device.
13. The fan according to at least one of the preceding claims, characterised in that the control device (10) for the flow paths in particular is at least one controllable tilting lever whose position is preferably changed by means of an electromagnetic actuator (11).
14. The fan according to at least claim 13, characterised in that the electromagnetic actuator (11) has magnetic coils arranged in the region of the bearings of the rotating axle and/or directly in the region of the housing of the drive device.
15. The fan according to at least one of the preceding claims, characterised in that the magnetic flux of the electromagnetic actuator is provided via at least a ferromagnetic hub and/or an axle of the clutch.
16. The fan according to at least one of the preceding claims, characterised in that the magnetic flux is provided via a ferromagnetic component which preferably is a sleeve (31) of ferromagnetic material inserted into a pulley of non-ferromagnetic design.
17. The fan according to at least claim 13, characterised in that the electromagnetic actuator (11) is arranged on the front side of the clutch.
18. The fan according to at least one of the preceding claims, characterised in that the coupling region for transmitting a torque is formed substantially by interengaging, concentric profiled structures (4) on at least one side of the driven element (2) and the drive element (3) each.
19. An apparatus for operating a ventilation system for a motor vehicle, having at least one drive unit, one connecting element and at least one fan according to at least one of the preceding claims.
20. Use of a fan according to at least one of the preceding claims for operating a ventilation system for a motor vehicle.

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