Abstract:
The invention relates to a combined blower/rotor ( 1 ) for a cooling fan of a motor vehicle, especially one having a reduced fan output. Said combined blower/rotor comprises a rotor ( 10 ) of an electric motor ( 30 ) and a blower ( 20 ) fastened to the rotor ( 10 ), said blower ( 20 ) being fixed to the rotor ( 10 ) without screws.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a fan-rotor combination for a cooling blower of a motor vehicle, in particular with low blower power, wherein the fan-rotor combination has a rotor of an electric motor and a fan fastened to the rotor. 
         [0002]    In the field of cooling blowers for internal combustion engines with electronically commutated electric motors, in the prior art, the fans are always fastened to the rotor by means of screws. Here, the fan lies on the rotor and the screws fasten the fan to the rotor (see  FIG. 1 ). Here, use is usually made of three screws, which are preferably screwed in with torque monitoring. 
       SUMMARY OF THE INVENTION 
       [0003]    It is an object of the invention to provide an improved fan-rotor combination. Here, the fan-rotor combination according to the invention should be of simple construction and cheap to manufacture. Furthermore, it should preferably be possible for the fan-rotor combination to be assembled manually without the use of tools or machines and in a short period of time, and said fan-rotor combination should furthermore have a small number of components. Here, the fan-rotor combination may preferably be designed for a low blower power and adapted to the demands of the emerging markets, such as for example a simple and robust design. 
         [0004]    The object of the invention is achieved by means of a fan-rotor combination for a cooling blower of a motor vehicle. 
         [0005]    The fan-rotor combination according to the invention has a rotor of a motor or of an electric motor and has a fan fastened to the rotor. Here, the fan is fixed to the rotor without the aid of additional components, in particular screws, or materially separate components, wherein the fan is fastened to the rotor preferably by means of an easily detachable positively locking connection. Said mechanical connection may if appropriate have non-positively locking attributes. The fastening of the fan to the rotor takes place on an axial portion and/or a radial portion of the rotor. Furthermore, the electric motor is preferably an electrically commutated external-rotor electric motor. 
         [0006]    According to the invention, a mechanical connection between the rotor and the fan is realized exclusively through the respective design of the rotor and/or of the fan. A connecting partner, which is required for the fastening of the fan to the rotor, of the fan and/or of the rotor is a constituent part, in particular a materially integral constituent part, of the fan and/or of the rotor respectively. Here, the connecting devices required for the fastening preferably extend through one another and are if appropriate secured. Here, the securing means are preferably constituent parts of the fan and/or of the rotor and are likewise preferably connected to the fan and/or to the rotor in a materially integral manner, for example by means of webs formed as predetermined breaking points. 
         [0007]    In one embodiment of the invention, the fan has a detent device which engages into a corresponding detent device of the rotor. In a further embodiment, the fan has an elastically flexible snap-in hook which is snapped into a corresponding recess of the rotor. Here, a locking position of the snap-in hook can be secured by means of a locking pin or bolt. Furthermore, in one embodiment of the fan-rotor combination, the fan and the rotor can be fixed to one another by means of a bayonet locking connection. Here, the bayonet hooks may in turn be secured by means of securing pins or bolts. 
         [0008]    Furthermore, in one embodiment of the invention, the fan may have a fastening projection which is preferably composed of plastic and which projects through a passage recess in the rotor. Here, that portion of the fastening projection which projects through the passage recess is deformed, which may be realized for example by means of an electrode, a heating element, a sonotrode or an anvil. In another embodiment of the invention, the rotor has a fastening lug which extends through a passage recess in the fan. That portion of the fastening lug which projects through the passage recess is deformed, in particular bent over. Furthermore, in an additional embodiment of the invention, the fan may have an internal thread which is screwed onto an external thread of the rotor. 
         [0009]    The embodiments of the invention may self-evidently also be kinematically reversed. Furthermore, they may also, including a kinematic reversal, be combined with one another. Furthermore, the invention is not restricted to the automotive field, but rather may also be applied to other fields such as for example heating blowers or dust extraction hoods. 
         [0010]    The invention yields a significant cost reduction, because in comparison with the prior art, three components, specifically the screws, are omitted because the function of torque transmission to the fan and the positioning of the fan on the rotor are realized exclusively by means of the design of the fan and of the rotor. In this way, axial installation space for the screw heads is eliminated, as a result of which the application is simplified owing to a reduction in required installation space. 
         [0011]    The snap-in or pressing-in processes can be carried out in a short time period and with less assembly outlay than a screw connection, as a result of which the assembly time for the fan is reduced. Furthermore, as a result of the fact that the metallic rotor is tightly clasped by a plastic hub, vibrations of the rotor are damped and blower noise is reduced. The fastening concept according to the invention permits manual assembly without additional aids and can therefore be used worldwide without great expenditure. As a result of the omission of components which require great outlay in ensuring quality, the creation of the individual components of the fan fastening according to the invention can be more easily localized. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention will be explained in more detail below on the basis of exemplary embodiments and with reference to the appended drawing, in which: 
           [0013]      FIG. 1  shows a sectional side view of a fan-rotor combination according to the prior art in an assembled state; 
           [0014]      FIG. 2  shows a sectional side view of a first embodiment according to the invention of a fan-rotor combination before the assembly thereof; 
           [0015]      FIG. 3  shows a sectional side view of the fan-rotor combination from  FIG. 2  in an assembled state; 
           [0016]      FIG. 4  shows a cut-away axial side view of a second embodiment according to the invention of a fan-rotor combination after the assembly thereof; 
           [0017]      FIG. 5  shows a perspective detail view of the fan-rotor combination from  FIG. 4  before the insertion of securing pins; 
           [0018]      FIG. 6  shows a sectional side view of a third embodiment according to the invention of a fan; 
           [0019]      FIG. 7  shows a plan view of a third embodiment according to the invention of a rotor; 
           [0020]      FIG. 8  shows a plan view of the fan from  FIG. 6 ; 
           [0021]      FIG. 9  shows a cut-away sectional side view of a first assembly step of the third embodiment of the fan-rotor combination; 
           [0022]      FIG. 10  shows, analogously to  FIG. 9 , a second assembly step of the fan-rotor combination; 
           [0023]      FIG. 11  shows, analogously to  FIG. 10 , a third assembly step of the fan-rotor combination; 
           [0024]      FIG. 12  shows, analogously to  FIG. 11 , a fourth assembly step of the fan-rotor combination; 
           [0025]      FIG. 13  shows a sectional side view of the third embodiment of the fan-rotor combination in an assembled state; 
           [0026]      FIG. 14  shows a sectional side view of a fourth embodiment according to the invention of a fan-rotor combination before the assembly thereof; 
           [0027]      FIG. 15  shows a sectional side view of the fan-rotor combination from  FIG. 14  in an assembled state; 
           [0028]      FIG. 16  shows a sectional side view of a fifth embodiment according to the invention of a fan-rotor combination before the assembly thereof; 
           [0029]      FIG. 17  shows a sectional side view of the fan-rotor combination from  FIG. 16  in an assembled state; 
           [0030]      FIG. 18  shows a sectional side view of a sixth embodiment according to the invention of a fan-rotor combination before the assembly thereof; and 
           [0031]      FIG. 19  shows a sectional side view of the fan-rotor combination from  FIG. 18  in an assembled state. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    The fan-rotor combination  1  or fan fastening  1  according to the invention illustrated in the drawing is characterized in that the components to be mechanically connected to one another, for example for cooling an internal combustion engine, that is to say a rotor or motor rotor  10  of an electric motor  30  and a fan  20 , are fixed to one another by means of positive locking in the axial direction A and radial direction R without an additional screw. For this purpose, at least one connecting device  100 ,  200  (for example a detent device such as a detent hook or a detent recess; a snap-in hook; a bayonet hook; a claw; an undercut; a fastening projection such as for example a lug, a dome, a peg, a pin, a bolt, a rib; a thread, a notch etc.—and a device corresponding thereto) is provided on/in the fan  20  and/or on/in the rotor  10 , which connecting device(s) serve(s) for fastening the fan  20  to the rotor  10 . All the components required for the functioning fan-rotor combination  1  originate from the two individual components fan  20  and rotor  10 , that is to say according to the invention, no materially separate components or other components aside from the fan  20  and the rotor  10  are used. In particular, the following embodiments of the invention may be realized: 
         [0033]    In the first embodiment of the invention illustrated in  FIGS. 2 and 3 , the fan  20  has, as a connecting device  200 , at least one but preferably at least two mutually opposite detent hooks  210  which project inwardly from a fan hub  22  and which engage into corresponding connecting devices  100 , designed as detent recesses  110 , of the rotor  10  on the axial portion  13  thereof. It is self-evidently also possible for the detent hooks to be provided on the rotor  10  and for the detent recesses to be provided on the fan  20 . Here, the respective snap-in contour  110 ,  120  or detent device  110 ,  120  may be of partially, sectionally or fully encircling form. 
         [0034]      FIGS. 4 and 5  show details of the second embodiment according to the invention of the fan-rotor combination  1 , wherein the respective connecting devices  100 ,  200  are formed as passage recesses  120  in a radial portion  14  of the rotor  10  and as snap-in hooks  220 , designed preferably as bending beams, of the fan hub  22 . Here, a radial portion of the fan  20  lies on the radial portion  14  of the rotor  10 , wherein the snap-in hooks  220  project substantially perpendicularly from the radial portion of the fan  20  and engage into the passage recesses  120  of the radial portion  14  of the rotor  10 . Here, the snap-in hooks  220  are preferably distributed substantially over a (segment of a) circle, wherein in each case two directly adjacent snap-in hooks  220  have their backs to one another, that is to say the two hook contours of the snap-in hooks  220  point away from one another. In each case two such adjacent snap-in hooks  220  engage at the longitudinal side into a passage slot  120  (passage recess  120 ) which widens with increasing radius. 
         [0035]    The snap-in hooks  220  may be secured by means of securing pins  222 , wherein either a securing pin  222  is pushed in between two directly adjacent snap-in hooks  220 , which securing pin, like that mentioned below, may then be materially integrally connected to the fan hub  22  via webs formed as predetermined breaking points, or a separate securing pin  222  may be provided for each snap-in hook  220 . In the latter case, it is preferable for a mount  224  in the form of a guide  224  or support  224 , which is preferably formed materially integrally with the fan hub  22 , to be provided for each securing pin  222 . Here, the respective mount  224  extends into the respective passage recess  120  of the rotor  10 , and the corresponding securing pin  222  is pushed in between the respective snap-in hook  220  and the respective mount  224 . It is self-evidently also possible for the snap-in hook  220  and passage recesses  120  to be interchanged. 
         [0036]    In the third embodiment of the invention, see  FIGS. 6 to 13 , use is made of a lockable bayonet connection (connecting devices  100 ,  200 ) of the fan  20  to the rotor  10 , in particular of the respective radial portions. Here, the fan hub  22  has, projecting away from its radial portion in the direction of the rotor  10 , at least one but preferably three bayonet hooks  230  which are arranged on a circular path and which can engage into bayonet recesses  130 , which correspond to said bayonet hooks, of the rotor  13 . Furthermore, on the circular path of the bayonet hooks  230 , the fan  20  has securing pins  232  which are integrally formed therewith by means of webs formed as predetermined breaking points, which securing pins secure a bayonet connection against self-release. Again, a kinematic reversal may self-evidently be realized. 
         [0037]      FIGS. 9 to 12  show such a realization of the bayonet connection. Firstly, the bayonet hooks  230  are inserted into the bayonet recess  130  until the radial portion of the fan  20  lies on the radial portion  14  of the rotor  10  ( FIG. 9 ). The fan  20  and rotor  10  are then rotated relative to one another about their common axis of rotation A until the bayonet hooks  230  engage under the rotor  10  ( FIG. 10 ). That portion of the respective bayonet recess  130  which is opened up between the respective bayonet hook  230  and the rotor  10  is occupied by the pressing-in of a securing pin  232  ( FIG. 11 ), such that the fan  20  can no longer rotate relative to the rotor  10  ( FIGS. 12 and 13 ). 
         [0038]    In the fourth and fifth embodiment of the fan-rotor combination  1  according to the invention, the fastening of the fan  20  to the rotor  10  is realized by means of deformed component regions of the fan  20  (fourth embodiment) and of the rotor  10  (fifth embodiment). Here, the fan  20  and/or the rotor  10  have/has component regions, lugs etc. which are deformed by a joining process (if appropriate thermally assisted, for example heating by means of ultrasound, hot air etc.) and thereby secure the component fastening. A reverse approach in each case may self-evidently also be used. 
         [0039]    In the fourth embodiment of the invention illustrated in  FIGS. 14 and 15 , the fan  20  has, projecting from its radial portion in the direction of the rotor  10 , at least one fastening projection  240  (connecting device  200 ) which may be designed for example as a pin, bolt, rib, dome or peg. For assembly, the fastening projections  240  of the fan  20  are plugged through passage recesses  140  (connecting device  100 ) in the radial portion  14  of the rotor  10 , and the portions which extend through the passage recesses  140  are subsequently plastically deformed by means of a deformation element  40 , which may take place for example using the abovementioned method. 
         [0040]    In the fifth embodiment of the invention illustrated in  FIGS. 16 and 17 , the rotor  10  has, projecting away from its radial portion  14 , at least one lug  150  (connecting device  100 ); the fan  20  has at least one passage recess  250  (connecting device  200 ) which corresponds to said lug and by means of which the fan  20  can be threaded onto the lug(s)  150 . During the mounting of the fan  20  on the rotor  10 , those portions of the lugs  150  which extend through the passage recesses  250  are bent over and thereby fix the fan  20  to the rotor  10 . 
         [0041]    In the final illustrated embodiment of the invention ( FIGS. 18 and 19 ), the fan  20  or the fan hub  22  and the rotor  10  have, as corresponding connecting devices  100 ,  200 , in each case one thread  160 ,  260  by means of which the fan  20  and rotor  10  can be directly screwed to one another. Here, the respective thread  160 ,  260  is an integral constituent part of the respective component. Here, it is preferable for the fan  20  to have an internal thread  260  and for the rotor  10  to have an external thread  160 . Here, the threads are preferably oriented such that a rotating rotor  10  “screws into” the fan  20 . 
         [0042]    All the embodiments of the invention may comprise domes, ribs, beads, hooks, notches, bulges etc. integrated on the rotor  10  and/or on the fan  20  for the purpose of undercut anchoring, torque transmission, positioning and/or simplification of assembly or joining processes. Optionally, the fastening of the rotor  10  and fan  20  may be secured against self-release of component parts (in particular snap-in hooks) by means of additional pressing, calking, (if appropriate thermally assisted) deformation or shearing-off of component regions (for example securing pins or bolts).