Patent Abstract:
The invention relates to a drive module, particularly for a fan in a motor vehicle, comprising a drive motor having a stator, at least one vibration-dampening decoupling element, and a fastening flange connected to the stator of the drive motor by the decoupling element, wherein the decoupling element is arranged in the interior of the stator and the fastening flange comprises a supporting element that is engaged in the decoupling element.

Full Description:
The invention relates to a drive module; in particular, the invention relates to a drive module for a fan in a motor vehicle. 
     Drive modules are standardized assemblies which can be handled separately and can be used universally. One field of use of a drive module of this type is a fan system in a motor vehicle, in which a fan is arranged between an intake section for fresh air and a distributor section for delivered air. A fan of this type can be constructed with the aid of a drive module, with the result that an installation and dismantling time of the fan is minimized and, in addition, accessibility of components which are situated in the adjacent sections, for example of a heat exchanger or a heater, is improved. 
     In drive modules in general and in a drive module for use in a fan, in particular, decoupling of the drive motor from its surroundings with regard to vibrations of every type is frequently required, in order to minimize solid-borne sound and vibrations which fatigue material. Elastic decoupling elements are usually used for decoupling purposes, such as steel springs. Usual decoupling requires additional installation space, for instance in the axial direction of a side facing the output or in a radial direction of the drive module. As a consequence of this, the resulting drive module is larger and less flexible in terms of its use. 
     SUMMARY OF THE INVENTION 
     The invention is based on the object of specifying an arrangement of vibration-damping decoupling elements on a drive module, which arrangement is advantageous with regard to function and installation space. 
     According to a first aspect, a drive module, in particular for a fan in a motor vehicle, comprises a drive motor with a stator, at least one vibration-damping decoupling element, and a fastening flange which is connected via the decoupling element to the stator of the drive motor, the decoupling element being arranged in the interior of the stator and the fastening flange having a supporting element which is in engagement with the decoupling element. 
     As a result, positioning of the decoupling elements in the axial direction behind the drive motor or radially outside the drive motor can be avoided, as a result of which the drive module can be of more compact construction. 
     A plurality of decoupling elements can be arranged radially symmetrically about the rotational axis of the drive motor along a circumference. As a result, a space within the stator can be used advantageously, which space would otherwise not be usable for components of the drive module. As a result of the given arrangement, the guidance of a concentric shaft or axle of the drive motor is not impaired. 
     The decoupling element can be configured as a hollow cylinder which comprises a radial inner face which is in engagement with the supporting element and a radial outer face which is in engagement with the stator. For example, the decoupling element can be configured in the form of an elongate sleeve, with the result that it can also transmit comparatively great forces, as can occur, for example, in the case of a small spacing of the decoupling elements from the rotational axis of the drive motor. 
     The stator can comprise a first and a second holder, each holder mounting the decoupling element in an axial direction. The decoupling element can thus already be fixed permanently on the stator before the latter is fastened to the fastening flange. In addition, the decoupling element can be configured in such a way that it is connected to the two holders of the stator by means of a frictional connection, with the result that handling of the stator in the context of a production process is simplified. In addition, each holder can bear in the radial direction against the decoupling element. 
     On a side which faces the fastening flange, the supporting element can have a shoulder which bears axially against the decoupling element. As a result, a minimum spacing can be defined between the stator and the fastening flange. 
     On a side which faces away from the fastening flange, the supporting element can carry a securing element which bears axially against the decoupling elements. The securing element can ensure rapid single-use mounting. As a result, for example, the stator which comprises the decoupling element can be pushed in a single work operation onto the axial supporting element of the fastening flange and can be secured there on the supporting element by way of a securing element. This arrangement also permits decoupling of vibrations of the stator from the fastening flange in the axial direction. 
     The stator can be enclosed by a rotor of the drive motor. In an arrangement of this type with outer rotor, a particularly highly integrated drive module can be realized as a result of the given arrangement of the decoupling elements on the inner side of the stator. 
     The fastening flange can define an outer contour of the drive module in the radial direction. As a result, a section of the drive module can be introduced through a fixing or mounting opening of a fastening structure in such a way that the fastening flange subsequently closes the opening and mounts the drive module in the opening. The fastening flange can have further elements, in order, for example, to form a closure with the surrounding structure or an airtight or watertight closure with regard to this structure, for instance a seal, a supporting ring and/or locking elements. Moreover, the fastening flange can comprise, for example, an electric connector element for the drive motor, for example a plug or a socket. 
     According to a second aspect, a fan module comprises a drive module with a drive motor with outer rotor and a fan wheel which is connected to the outer rotor. The fan wheel can be formed in such a way that the drive motor largely fills the space which is defined by the fan wheel, with the result that the fan module is particularly compact. In particular, the fan wheel can have a semi-axial construction with a concave boundary which faces the drive motor. 
     According to a third aspect, a motor vehicle comprises a fan system having the fan module as described above. The particularly compact construction of the fan module results, for example, in a greater structural scope for other elements of the motor vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following text, the invention will be described in greater detail with reference to the appended drawings, in which: 
         FIG. 1  shows a diagrammatic illustration of a fan system in a motor vehicle; 
         FIG. 2  shows an isometric view of an exploded illustration of part of the drive module from  FIG. 1 ; 
         FIG. 3  shows a sectional view of the mounted part from  FIG. 2 ; and 
         FIG. 4  shows a sectional view of a fan module using the mounted part from  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a diagrammatic illustration of a motor vehicle fan system  100 . A motor vehicle  110  comprises an intake section  120 , a fan module  130  and a distributor section  140 . The fan module  130  comprises a fan wheel  150  and a drive module  160 . Optional elements of the motor vehicle fan system  100  are not contained in the illustration of  FIG. 1 , such as filters, flaps, valves, heat exchangers, condensers and the like which are not further relevant in the present context. The drive module  160  sets the fan wheel  150  in rotation, with the result that air is sucked into the fan wheel  150  from an outer side of the motor vehicle  110  through the intake section  120  and is subsequently conveyed through the distributor section  140  to the inside of the motor vehicle  140 . A use of the fan module  130  in a ventilation system outside a motor vehicle  110  is likewise possible. 
     The intake section  120  and the distributor section  140  are frequently configured jointly in a common section. The fan module  130  can be capable of being inserted into the intake section  120 , the distributor section  140  or the integrated section in the manner of a cartridge. In the surroundings of the fan module  130 , the relevant section can have an element which converts a radial flow direction of air which flows out of the fan wheel  150  into a linear flow direction, for example a pressure increasing spiral which additionally brakes and compresses the air which flows away from the fan wheel  150 . 
       FIG. 2  shows an isometric illustration of an exploded drawing of a part  200  of the drive module  160 . The part  200  which is shown comprises a fastening flange  205  with four axial supporting elements  210  and a stator  220  which can be coupled to the fastening flange  205  by means of four elastic decoupling elements  215 . The decoupling elements  215  are composed of an elastic material which preferably has high internal damping, for example silicone or rubber. The stator  220  comprises a first holder  225  and a second holder  230 , a first magnetic flux element  235 , a lower rotary bearing  240 , an upper rotary bearing  245  and securing elements  250 . The supporting elements  210  have shoulders  260 . 
     The stator  220  is configured in such a way that it can be mounted on the fastening flange  205  as a unit which can be handled separately. To this end, the first flux element  235  and the four decoupling elements  215  are inserted between the first holder  225  and the second holder  230  at the correspondingly provided positions, before the first holder  225  is connected to the second holder  230 . When the first holder  225  and the second holder  230  are connected to one another, the decoupling elements  215  and the first flux element  235  are delimited in each case in the axial direction on both sides by the two holders  225  and  230 . A clamping action which fixes the two holders  225  and  230  against one another is induced by a frictional connection between the outer circumference of the decoupling elements  215  and the corresponding radial receptacles of the lower holder  225  and the upper holder  230 . Furthermore, there is a frictional connection between the inner circumference of the first magnetic flux element  235  and the holders  225  and  230 . Fixed in this way, a winding (or coils) can be applied to the stator  220 , which winding comprises a number of conductor sections which extend in the axial direction along the circumferences of the holders  225  and  230 . These wire pieces can be fixed by means of the projections of the holders  225  and  230 , which projections extend in the axial direction. Together with the first magnetic flux element  235  (also called short-circuit plate or flux plate), the windings can form coils or electromagnets for magnetic coupling to a rotor which encloses the stator  220 . 
     The lower rotary bearing  240  and the upper rotary bearing  245  are connected in a rotationally stable manner to the first holder  225  and the second holder  230  and are configured for receiving an axle or shaft which is connected to the stator. In an alternative embodiment, one or both of the bearings  240  and  245  can also be of rotatable configuration with regard to the holders  225 ,  230  which surround them. 
       FIG. 3  shows a lateral sectional view of the mounted part  200  of the drive module  160  from  FIG. 2 . The lower rotary bearing  240  and the upper rotary bearing  245  are not shown. The approximately hollow-cylindrical decoupling elements  215  bear on their inner circumference in a positively locking manner against the supporting elements  210 . The decoupling elements  215  are fixed in the axial direction downward by shoulders  260  in the axial supporting elements  210  and upward by means of the securing elements  250  on the supporting elements  210 . The securing elements  250  can be, for example, self-locking securing rings. As an alternative to this, the securing elements  250  can be pressed, for example, onto an end section of the supporting element  210  or the latter can be fit into them. To this end, the end sections of the supporting elements  210  can be shaped conically. In a further embodiment, the securing elements  250  are connected non-positively to the supporting elements  210 , for example, by means of adhesive bonding, welding, remelting, brazing, screwing or a further known connection method. 
     The decoupling element  215  has in each case coaxial recesses on its two end faces in the axial direction, into which coaxial recesses hollow-cylindrical engagement elements of the first holder  225  and the second holder  230  of the stator  220  engage, with the result that the decoupling element  215  is fixed both in the radial and in the axial direction with respect to the stator  220 . 
     The axial supporting element  210  is configured in one piece with the fastening flange  205 , a multiple-piece construction also being possible in an alternative embodiment. The supporting element  210  has a radial spacing from the first holder  225 . The magnitude of the spacing defines a maximum compression travel of the decoupling element  215  when the stator  220  is deflected with respect to the fastening flange  205 . A great spacing also assists absorption of pronounced vibrations, but at the same time allows a relatively great deflection of the stator  220  with respect to the fastening flange  205 , with the result that the position of the stator or of an element which is connected to it is defined less precisely. 
     The radial contact of the securing element  250  with the second holder  230  of the stator  220  is optional. The first magnetic flux element  235  is formed by a number of rings made from a softly magnetic material which are stacked on one another. Alternative embodiments, for example in the form of a single-piece or multiple-piece cylinder or a spiral, are likewise possible. 
       FIG. 4  shows a lateral sectional view of a fan module  130  using the drive module  160  of  FIG. 1  which comprises the part  200  of  FIGS. 2 and 3 . In addition to the drive module  160 , the fan module  130  comprises a fan wheel  410 , permanent magnets  420 , a second magnetic flux element  430  and an axle  440 . In the selected illustration, the supporting elements  210  and the elastic decoupling elements  215  are shown from outside, that is to say in a non-sectioned state. For the sake of clarity, no coils are shown on the stator  220  either. The fan module  160  is universally suitable for use in fan systems  120 ,  130 ,  140 , the high space utilization with simultaneously satisfactory vibration damping particularly favoring use in a motor vehicle  110 . 
     The fan wheel  410  is of the semi-axial type, that is to say it comprises fan blades for sucking in air from the axial direction (from the left) and fan blades for discharging the air which has been sucked in the radial direction. The fan wheel  410  is connected to the drive module  160  by means of the axle  440 . The axle  440  is fastened fixedly to the fan wheel  410  so as to rotate with it, for example by being molded on, being cast on, being pressed in, being adhesively bonded, being welded or being fit. A rotor  400  of the drive module  160  is formed by the permanent magnets  420  and the second magnetic flux element  430  which are attached fixedly to the fan wheel  410  so as to rotate with it. The second magnetic flux element  430  produces a magnetic flux on an outer circumference of the permanent magnets  420  which are arranged in the manner of a ring. 
     The axle  440  can be secured at its end which faces the fastening flange  205  against sliding out of the lower rotary bearing  240 . This securing means can be accessible, for example, by a corresponding mounting opening (not shown) in the fastening flange  205 , in order for it to be possible to disconnect the fan wheel  410  from the drive module  200  as required. As an alternative to this, the axle  440  can be secured in the axial direction by means of a non-releasable connection against sliding out of the lower rotary bearing  240 , for example by means of a securing ring which has been pressed on or fit, a circlip or another element with a comparable effect. 
     The fastening flange  205  is dimensioned in such a way that, on its right hand side, it fills a mounting opening, through which the fan wheel  410  can pass. The mounting opening can be situated on an air section of the motor vehicle  110  from  FIG. 1  and can be, for example, circular.

Technology Classification (CPC): 5