Abstract:
The invention relates to a fan module ( 1 ), in particular for air conditioners in vehicles, comprising an electric motor ( 12 ) and a fan rotor ( 20 ), wherein the electric motor ( 12 ) and the fan rotor ( 20 ) are arranged on a rotor shaft ( 11 ) and are connected to each other by means of a drive connection ( 22, 30 ), and wherein the electric motor ( 12 ) is designed to drive the fan rotor ( 20 ) via a drive connection ( 22, 30 ), wherein the drive connection ( 22, 30 ) has a positive connection ( 22, 30 ) to a driver ( 30 ) and a mating driver piece ( 22, 24 ), wherein the driver ( 30 ) on the electric motor ( 12 ) and the mating driver piece ( 22 ) on the fan rotor ( 20 ) are arranged spaced apart radially with respect to the rotor shaft ( 11 ), wherein the driver ( 30; 40 ) is formed and designed in the direction of rotation of the fan rotor ( 20 ) to actuate the mating driver piece ( 22 ) in order to transmit a force from the electric motor ( 12 ) to the fan rotor ( 20 ).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a fan module, in particular for airconditioning systems in vehicles, having an electric motor and a fan rotor, wherein the electric motor and the fan rotor are arranged on a rotor shaft and are connected to one another by means of a drive connection, and wherein the electric motor is configured to drive the fan rotor via the drive connection. 
         [0002]    The passenger compartment in vehicles is ventilated for the purpose of airconditioning, for increasing the comfort and for the sake of travelling safety by means of a ventilation system to which a heating and/or airconditioning system is connected. In order to feed the air into the passenger compartment, a fan module is connected to the ventilation system, said fan module sucking in fresh air from the surroundings of the vehicle and directing it into the heating and/or airconditioning system in order to bring the sucked-in air to the desired temperature. The air which flows through the passenger compartment is usually carried out of the passenger compartment through ventilation slits, for example on the parcel shelf. 
         [0003]    The fan module which is connected to the ventilation system is usually constructed as a radial compressor which is driven by an electric motor. The electric motor is integrated here in terms of its design into the fan module and is usually embodied as a brushless electric motor in the form of an external rotor. In order to transmit the torque of the electric motor to a fan rotor of the fan module, the fan module usually has a shaft-hub connection which is embodied as a positively locking or frictionally locking connection. Owing to the large temperature range in which the fan module is used, the shaft-hub connection must be of high quality in order to transmit the torque of the electric motor to the fan rotor reliably and quietly. 
       SUMMARY OF THE INVENTION 
       [0004]    The object of the invention is to make available an improved fan module. 
         [0005]    According to the invention, a fan module is proposed, in particular for airconditioning systems in vehicles, having an electric motor and a fan rotor. In this context, the electric motor and the fan rotor are arranged on a rotor shaft and are connected to one another by means of a drive connection. The electric motor drives the fan rotor via the drive connection, wherein the drive connection has a positively locking connection to a driver and a driver counterpart. The driver on the electric motor and the driver counterpart on the fan rotor are arranged spaced radially apart from the rotor shaft. In this context, the driver is configured to activate the driver counterpart of the fan rotor in order to transmit force from the electric motor to the fan rotor. 
         [0006]    In this way, a positively locking connection for the drive connection is made available, by means of which the torque can be reliably transmitted at a wide variety of temperatures, wherein in addition improved running of the fan rotor is made available. 
         [0007]    In a further embodiment of the invention, the driver has at least two driver elements which are embodied in the form of a pin and are oriented parallel to the rotational axis, wherein the activation elements are arranged in a U shape in the direction of rotation and form the receptacle. In this way, a particularly simple positively locking connection is made available for transmitting a torque of the electric motor to the fan rotor. 
         [0008]    In a further embodiment of the invention, the driver counterpart is embodied as a reinforcing rib of the fan rotor, wherein the driver activates the reinforcing rib of the fan rotor in order to drive the fan rotor. As a result of this configuration, the fan rotor can be of particularly simply design. 
         [0009]    In a further embodiment of the invention, the receptacle has a press fit with respect to a thickness of the reinforcing rib in an attachment region of the reinforcing rib. In this way, the generation of noise when the torque of the electric motor is transmitted to the housing rotor can be reliably avoided. 
         [0010]    In a further embodiment of the invention, the driver is embodied in one piece with, and from the same material as, a housing part of the housing of the electric motor. In this way, the positively locking connection can be manufactured cost-effectively, for example in an injection molding method. 
         [0011]    In a further embodiment of the invention, the fan module comprises a rotor shaft which is arranged on the rotational axis of the fan module. The rotor shaft serves to axially secure the fan rotor and is connected thereto by means of a positively locking connection. In this context, the driver is configured predominantly to transmit the torque of the electric motor, while the positively locking connection brings about the axial securement of the fan rotor. 
         [0012]    In this way, the positively locking connection can be made smaller and more cost-effective by virtue of a cost-effective selection of material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The invention will be explained in more detail below with reference to figures, in which: 
           [0014]      FIG. 1  shows a longitudinal section through a first fan module along a rotational axis; 
           [0015]      FIG. 2  shows a detail of the longitudinal section, shown in  FIG. 1 , through the first fan module; 
           [0016]      FIG. 3  shows a longitudinal section through a second fan module along the rotational axis; 
           [0017]      FIG. 4  shows a section transversely with respect to the rotational axis through the second fan module; and 
           [0018]      FIG. 5  shows a perspective partial section through the second fan module. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]      FIG. 1  shows a longitudinal section through a first fan module  1 , and  FIG. 2  shows a detail of the longitudinal section shown in  FIG. 1 .  FIG. 1  and the following figures also illustrate a coordinate system with directions x, y and z which are perpendicular to one another, with reference to which the method of functioning of the fan module  1 ,  2  is described. 
         [0020]    The first fan module  1  comprises an electric motor  12  which comprises a first rotor  17  and a stator  18 . The stator  18  comprises a carrier  9  which is embodied in a rotationally symmetrical fashion with respect to a rotational axis  10  (y direction) of the first rotor  17 , wherein a plurality of windings  13  of the stator  18  are arranged radially on the outside around the carrier  9 . On the inside, the carrier  9  accommodates two bearings  22  for supporting the first rotor  17 . 
         [0021]    The first rotor  17  of the electric motor  12  is embodied as an external rotor and comprises a rotor housing  19  which radially partially engages around the stator  18 , and magnets  14  which are arranged radially on the rotor housing  19 , on the inside in the circumferential direction. In addition, the fan module  1  comprises a rotor shaft  11  on which the rotor  17  of the electric motor  12  is arranged. The rotor shaft  12  is arranged on the rotational axis  10  of the first fan module  1  and is mounted rotatably about the rotational axis  10  by the bearings  22  of the stator  18 . On an end side (x-z plane) which faces a first fan rotor  20 , explained in more detail below, the first rotor housing  19  of the first rotor  17  has a first driver  30  which is embodied in the direction of the first fan rotor  20  (y direction) and is spaced apart radially from the rotational axis  10 . In addition, the rotor housing  19  has a cooling air fan  38  which supplies the electric motor  12  with cooling air during operation. 
         [0022]    A first fan rotor  20  is arranged underneath the electric motor  12 , on the rotational axis  10 . The first fan rotor  20  is embodied as a radial compressor with a plurality of compressor blades  21  lying radially on the outside, and feeds air from an input side, arranged on the underside, of the fan module  1  to an output side, arranged radially on the outside, of the fan module  1  (not illustrated). 
         [0023]    The first fan rotor  20  comprises a region  27  which is arranged radially on the inside and is embodied in the form of a trough, a plurality of reinforcing ribs  22  and a bearing region  23  of a bushing  26  for a frictionally locking connection to the rotor shaft  11 . The trough-shaped region  27  is embodied so as to be open towards the first rotor  17  of the electric motor  12 . The reinforcing ribs  22  of the first fan rotor  20  are arranged at regular angular intervals of 60° in the circumferential direction about the rotational axis  10  in the trough-shaped region  27  of the first fan rotor  20  and connect the bushing  26  and the region arranged radially on the outside to the compressor blades  21 . The reinforcing ribs  22  are embodied in the form of plates, in one piece with, and from the same material as, the first fan rotor  20 . The arrangement of the reinforcing ribs  20  in the trough-shaped region  27  ensures low-oscillation support of forces from the frictionally locking connection between bushing  26  and rotor shaft  11  and from the compressor blades  21  of the first fan rotor. 
         [0024]    The bushing  26  is arranged radially on the inside of the trough-shaped region  27 , wherein the bearing region  23  of the bushing  26  faces the rotor shaft  11 . The bushing  26  with the bearing face  23  and the rotor shaft  11  are matched to one another in such a way that a frictionally locking connection  11 ,  23  is present on the bushing  26  and the rotor shaft  11 . The frictionally locking connection  11 ,  23  serves to attach the first fan rotor  20  axially to the electric motor  12  and to bear the first fan rotor  20  by means of the bearings  22  of the electric motor  12 . A torque of the electric motor  12  is preferably to be transmitted via a positively locking connection  22 ,  30 , explained in more detail below. 
         [0025]    The first driver  30  comprises a driver base  32  and driver elements  31  which are arranged thereon and are embodied in the form of pins. The driver base  32  is arranged on the first rotor housing  19  of the first rotor  17  and is oriented axially in the direction of the first fan rotor  20 . In addition, the driver base  32  is embodied in the circumferential direction of the first fan rotor  19 . The driver elements  31  are each arranged in pairs in the circumferential direction of the electric motor  12  on the driver base  32  of the rotor housing  19 . The driver elements  31  of the first driver  30  are embodied here in the y direction and arranged projecting away from the driver base  32  in a U shape, wherein in each case two driver elements  31  comprise at least partially a reinforcing rib  22  as a driver counterpart in the mounted state of the first fan module  1 . In this context, the two driver elements  31  of the first driver  30  form a first receptacle  33  into which the reinforcing rib  22  engages as a corresponding driver counterpart in the mounted state of the first fan module  1 . The first receptacle  33  of the first driver  30  has a first longitudinal axis  34  which is oriented parallel to the rotational axis  10  of the first fan module  1 . The first receptacle  33  is adapted to a thickness of the reinforcing rib  22  in such a way that it forms a press fit with respect to the thickness of the reinforcing rib  22 , in the bearing region of the first receptacle  33 . The press fit of the receptacle  23  and on the reinforcing rib  22  in this context has the advantage that the generation of noise by the fan module  1  is reduced. 
         [0026]    If the electric motor  12  of the first fan module  1  is energized, the electric motor  12  makes available a torque for driving the first fan rotor  20  at the first rotor  17 . The torque of the electric motor  12  is transmitted from the first rotor  17  of the electric motor  12  to the first fan rotor  20  by the engagement of the driver  30  in the reinforcing ribs  22  of the first fan rotor  20 . In this context, through the formation of the first driver  30  and of the reinforcing rib  22  a positively locking connection is made available between the electric motor  12  and the first fan rotor  20 , which connection is easy to mount and can reliably transmit a high torque of the electric motor  12  to the first fan rotor  20 . As a result of the engagement of the driver  30  in the reinforcing ribs  22 , the positively locking connection  22 ,  30  has a temperature-stable behavior, with the result that even in the case of critical high temperatures, such as often occur in the region of the engine compartment of a motor vehicle, the torque of the electric motor  12  can be reliably transmitted. 
         [0027]    In the embodiment, the frictionally locking connection  11 ,  23  is configured, as mentioned above, to attach the first fan rotor  20  to the first rotor  17  of the electric motor  12 . Owing to the transmission of torque via the positively locking connection  22 ,  30  by means of the driver  30  and the reinforcing ribs  22 , the positively locking connection  11 ,  23  to the axial forces which are lower than the forces arising from the transmission of torque are configured to attach the first fan rotor  20  to the electric motor  12 . In addition, the frictionally locking connection  11 ,  23  between first fan rotor  20  and the electric motor  12  can be formed in a temperature-stable fashion as a result of the low loading. 
         [0028]    As a result of the first driver  30  being embodied in one piece with, and from the same material as, the first rotor housing  19  of the electric motor  12 , the first driver  30  can easily be manufactured in an injection molding method together with the first rotor housing  19 . 
         [0029]      FIG. 3  shows a section along the rotational axis  10  through a second fan module  2 .  FIG. 4  shows a section transversely with respect to the rotational axis  10  of the second fan module  2 , and  FIG. 5  shows a perspective section through the second fan module  2  along the rotational axis  10 . 
         [0030]    The second fan module  2  is embodied here essentially in the same way as the first fan module  1  which is shown in  FIGS. 1 and 2 , and said second fan module  2  comprises a second fan rotor  50  and the second rotor  60  of the electric motor  12  with a second rotor housing  61 . The second rotor housing  61  comprises, on the end side facing the second fan rotor  50 , a second driver  40  which projects into the trough-shaped region  37  of the second fan rotor  50 . In the embodiment shown in  FIGS. 3 to 5 , the second fan rotor  50  is also attached to the electric motor  12  by means of the frictionally locking connection  11 ,  23  between the bushing  26  of the second fan rotor  50  and the rotor shaft  11 . 
         [0031]    The second driver  40  comprises a plurality of pins  36  which, for example, are embodied in a hollow-cylindrical fashion in the embodiment. In each case a pin  36  of the second driver  40  has second longitudinal axis  37  which is arranged parallel to the rotational axis  10 . In this context, the pins  36  are connected by the rear side to, in each case, one housing rib  35  of the second rotor  50 . The pins  36  of the second driver  40  are arranged approximately at a 120° angular distance from one another about the rotational axis  10  of the second fan module  2  at an identical radial first distance from the rotational axis  10  of the second fan module  2 , around said rotational axis  10 . 
         [0032]    The second fan rotor  50  comprises, as does also the first fan rotor  20  shown in  FIGS. 1 and 2 , a plurality of reinforcing ribs  22  which connect an outer radial housing part to the bushing  26  in the trough-shaped region  27 . The reinforcing ribs  22  are arranged at an approximately 60° angular distance from one another about the rotational axis. On the reinforcing ribs  22 , the second fan rotor  50  has, in each case, a thickened portion  24 , embodied in a cylindrical fashion, as a corresponding driver counterpart to the second driver  40 . The thickened portion  24  comprises a third longitudinal axis  25 , which, like the first longitudinal axis  37  of the first driver  30 , is arranged parallel to the rotational axis  10  (y direction). In addition, the third longitudinal axis  25  of the thickened portion  24  is arranged in each case in the plane of the corresponding reinforcing rib  22 . The third longitudinal axes  37  of the thickened portions  24  are arranged in a circular shape at a second distance from the rotational axis  10 , around the latter. In the embodiment, the first distance from the longitudinal axis of the pins  36  is selected to be smaller than the second distance from the third longitudinal axes  37  of the thickened portions  24 . As a result, the position of the second fan rotor  50  in the assembly can be reliably defined. However, in order to define the position, it is also alternatively conceivable to select the first distance of the pins  36  from the rotational axis  10  to be larger than the second distance of the thickened portions  24  from the rotational axis  10 . 
         [0033]    In the mounted state of the second fan module  2 , in each case a pin  36  of the second driver  40  projects in between two reinforcing ribs  22 , wherein each pin  36  has a point of contact with, in each case, one thickened portion  24  of a reinforcing rib  22 . In this context, in each case two adjacent pins  36  form a second receptacle  28  in which the reinforcing rib  22  with the thickened portion  24  is arranged in the mounted state. In this context, a positively locking connection  22 ,  24 ,  40  is made available which is configured to transmit the torque of the electric motor  12  to the second fan rotor  50 . If a torque bears against the second rotor  60 , in each case a pin  36  presses in the direction of the torque of the electric motor  12  at the point of contact against the thickened portion  24 , bearing against the pin  36 , of the reinforcing rib  22  and transmits the torque of the electric motor  12  to the second fan rotor  50 . 
         [0034]    The hollow cylindrical formation of the pins  36  also has the advantage that in each case a pin  36  adapts, by virtue of elastic deformation, to the distance between two thickened portions  24  which are arranged one next to the other. In this context, the pin  36  or the thickened portions  24  of the second fan rotor  50  are matched to one another in such a way that a press fit is present between the pin  36  and the two assigned thickened portions  24 , and that the pin  36  is stressed or pressed in between the two thickened portions. This permits the second fan rotor  50  to be attached axially to the second rotor  60  of the electric motor  12  and/or permits a securing force which is additional to the frictionally locking connection  26 ,  11  to be built up. This advantage also ensures low-noise running of the fan module  50 . 
         [0035]    Mounting of the second fan module  2  can be carried out more easily by virtue of the fact that the pins  36  of the second driver  40  are arranged at a regular distance, at a 60° angle in the embodiment, about the rotational axis  10  of the second fan module  2 . This ensures that for the second fan rotor  50  six possible mounting positions can be made available on the second rotor  60  of the electric motor  12 , with the result that a mounting position can be quickly found. 
         [0036]    The embodiments of fan modules  1 ,  2 , and the components thereof, explained with reference to the figures constitute preferred or exemplary embodiments of the invention. In addition to the embodiments which are described and illustrated, further embodiments are conceivable which can comprise further refinements or combinations of the described features. 
         [0037]    In particular, it is to be noted that the shape and the number or the arrangement of the drivers  30 ,  40  and of the corresponding driver counterpart  22 ;  24 , that is to say of the reinforcing ribs  22  or of the thickened portions  24  on the reinforcing ribs  22  can vary. It is therefore, for example, also conceivable for the positively locking connection to be configured with just one driver element  32 ;  36  and one or two corresponding driver counterparts or reinforcing ribs  22 . Alternatively it is also conceivable to form the thickened portion  24  on the reinforcing rib  22  of the second fan rotor with a different cross section than the circular cross section shown. It is, for example, conceivable to form the thickened portion  24  of the reinforcing rib  22  with an elliptical, a rectangular or a polygonal cross section. It is also to be noted that the driver counterparts  22 ,  24  which are shown in the embodiment are exemplary and can, of course, also be constructed in other ways. It is, for example, also conceivable for the cooling air fan  38  which is arranged in the rotor housing to be integrated with cooling air feed laminations in the fan rotor  20 ;  50 , wherein the driver  30 ;  40  engages in the feed laminations of the cooling air fan  38  as a corresponding driver counterpart. 
         [0038]    It is also conceivable for the fan rotor  20 ,  50  to be attached axially to the reinforcing ribs  22  or to the positively locking connection  22 ,  24 ,  30 ,  40  by means of the press fits of the drivers  30 ,  40 .