Patent Document

[0001]    This application is a National Stage completion of PCT/EP2009/056454 filed May 27, 2009, which claims priority from German patent application serial no. 10 2008 002 443.0 filed Jun. 16, 2008. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention concerns an electric machine with a stator support for a hybrid drive train. 
       BACKGROUND OF THE INVENTION 
       [0003]    From automotive technology vehicles with a hybrid drive train, in particular utility vehicles, are known. The hybrid drive train usually comprises an internal combustion engine coupled to a transmission via a clutch. As an additional drive source an electric machine is provided and arranged for example on the transmission input side. In this way the vehicle can be driven by the internal combustion engine and/or by the electric machine. The electric machine can be operated as a motor or as a generator. As the transmission, in this case an automated transmission is provided. 
         [0004]    In the known hybrid drive trains the electric machine is integrated in the transmission housing. For this it is necessary, for example, that the stator support of the electric machine is of correspondingly elaborate design enabling it to be integrated in the transmission housing. In addition structural modifications of the transmission housing are needed in order to adapt it to the stator support and to the other components of the electric machine. Thus, the ordinary transmission housings used in vehicles having no electric machine cannot be used. 
         [0005]    SUMMARY OF THE INVENTION 
         [0006]    The purpose of the present invention is to propose an electric machine of the type described at the start, which is as simply designed as possible and which allows the electric machine to be integrated in the transmission housing without design modifications. 
         [0007]    The stated objective of the invention can be achieved by an electric machine with a stator support for a hybrid drive train having a transmission housing to accommodate the transmission and a hybrid housing to accommodate the electric machine and, for example, the clutch of a vehicle, in particular a utility vehicle, such that the stator support is made integrally with an attachment for fastening onto the hybrid housing and the transmission housing. This produces a particularly simply designed stator support for the electric machine, which combines the various necessary connections and interfaces in only a single component. 
         [0008]    In one possible embodiment variant of the invention it can be provided that a flange collar or the like is formed on the stator support as the attachment. The attachment can also be provided as a detachable element on the stator support. When the attachment is formed as a flange collar, the stator support can be clamped between the hybrid housing and the transmission housing in the most simple manner without having to make structural modifications to the transmission housing. In this way an adaptively modified electric machine is proposed, which can be fitted onto already existing transmission housings that can, for example, also be used in other drive trains. 
         [0009]    Preferably the flange collar on the like can have a plurality of axial through-bores or the like distributed around its circumference. These through-bores allow the passage of bolts that are provided, for example, for fastening the hybrid housing to the usual type of transmission housing. Advantageously, in this way no additional assembly effort is entailed for fitting the stator support to the transmission housing. 
         [0010]    According to a possible further development of the invention, it can be provided that the shape of the flange collar is in each case adapted to the axial contour of the transmission housing and the hybrid housing. In this way the stator support realizes the SAE connections or SAE interfaces usually provided, for example, on a crankcase of the internal combustion engine for fastening onto the transmission housing. Thus, the stator support can be interposed axially between the hybrid housing and the transmission housing, and only the axial length of the hybrid drive train will then be increased by the axial width of the stator support. In other respects the transmission housing or the hybrid housing can be fitted onto a standard crankcase of the internal combustion engine without modifications. 
         [0011]    It is possible for the flange collar of the stator support to have a plurality of cut-outs or the like, in order advantageously to reduce the weight of the stator support. Furthermore, a suitably located cut-out can form a passage for the throw-out tappet or thrust rod of the clutch actuating mechanism if the clutch control unit is not arranged centrally. 
         [0012]    A related possible design of the invention can provide that the stator support can be connected to a transport security element. The transport security element can for example be in the form of a cup-shaped component fixed, on the one hand, to the stator support and, on the other hand, to the rotor of the electric machine in order to ensure safety during transport and assembly. This prevents the stator support from coming into contact with the rotor of the electric machine due to the attractive force of the permanent magnets of the electric machine during transport, assembly, or replacement. Transport security elements designed in other ways can also be used. After transport or during assembly, the transport security element can be removed again from the stator support in the most simple manner. 
         [0013]    Particularly advantageously, the stator support of the electric machine according to the invention can be made as an integrated cooling jacket or the like. For that purpose the stator support can for example comprise at least one integrated cooling duct of the cooling system of the electric machine. Preferably, on at least one main bearing point or the like of the stator support, venting means can be provided, for example in the form of a venting screw or similar, in order to vent the cooling system of the electric machine. The main bearing point is a recess formed during the casting of the stator support. Thus, the proposed stator support is designed so that the cooling system of the electric drive can be vented. 
         [0014]    In another further development of the invention, it can be provided that the stator support, for example in its peripheral area, has a cooling duct connection, an electric current terminal and/or a temperature sensor connection. This extends the functionality of the stator support and thereby saves otherwise necessary additional components. In this way all the interfaces required for the electric drive can be located on the stator support. Preferably, a rotor position sensor can also be arranged in or on the stator support. 
         [0015]    For example, a machine with an internal rotor can be used as the electric machine. However, other structures can also be used for the electric machine. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0016]    Below, the present invention is explained in greater detail with reference to the drawings, which show: 
           [0017]      FIG. 1 : Sectional view of an electric machine with a stator support in a hybrid drive train 
           [0018]      FIG. 2 : Three-dimensional isolated-component view of the stator support of the electric machine 
           [0019]      FIG. 3 : Three-dimensional view of the side of the electric machine facing toward the transmission 
           [0020]      FIG. 4 : Three-dimensional view of the side of the electric machine facing toward the internal combustion engine 
           [0021]      FIG. 5 : Partially sectioned view of the electric machine, and 
           [0022]      FIG. 6 : Three-dimensional partial view of the stator support with a coolant connection. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]      FIG. 1  shows, as an example, a partial view of a hybrid drive train; in the description of the figure some components known per se are not indexed. 
         [0024]    In a familiar way, the hybrid drive train comprises an internal combustion engine (not shown), which is coupled by means of a clutch (indicated only in part) to a transmission, the clutch fork  1  provided for actuating the clutch being shown. Depending on the embodiment concerned, the transmission may be a manual-shift gearbox, an automated shift transmission or the like. The transmission is arranged in a transmission housing  3 . The electric machine  2  and the clutch are accommodated in a hybrid housing  4  arranged between a crankcase (not shown) of the internal combustion engine and the transmission housing  3 . 
         [0025]    The proposed electric machine  2  comprises a stator support  5  formed integrally with an attachment or the like for fastening onto the hybrid housing  4  and the transmission housing  3 . Thus, the electric machine  2  designed according to the invention can be adapted to the transmission housing  3  so that an ordinary transmission housing  3 , also used in drive trains without an electric drive, can be used without the need for structural modifications. 
         [0026]    The design of the stator support  5  according to the invention can be seen particularly clearly in  FIGS. 2 ,  3  and  4 . As the fastening attachment a flange collar  6  is formed radially on the outside on the stator support  5 . The flange collar  6  has a plurality of axially orientated through-bores  7  distributed around its circumference. The through-bores  7  receive bolts (not shown) to fasten the stator support  5  between the hybrid housing  4  and the transmission housing  3 . 
         [0027]    The shape of the flange collar  6  is adapted to the respective axially orientated contours of the transmission housing  3  and the hybrid housing  4 . In this way the stator support  5  can be clamped axially between the transmission housing  3  and the hybrid housing  4 , as can be seen particularly clearly in  FIG. 1 . 
         [0028]    Thanks to the design of the stator support of the electric machine  2  according to the invention no additional assembly effort is involved, since the stator support  5  is only fitted axially between the hybrid housing  4  and the transmission housing  3  without the need for any shape modifications, so that only the axial length of the hybrid drive train is increased. 
         [0029]    The flange collar  6  of the stator support  5  has several cut-outs  8 , as can be seen particularly clearly in  FIGS. 2 ,  3  and  4 . Thanks to the cut-outs  8 , on the one hand, the weight of the stator support  5  can be reduced, and, on the other hand, an appropriately positioned cut-out  8  can provide a passage for a throw-out tappet of the clutch. Furthermore, a fixing strip  20  is provided on the stator support  5 . Additional components can be held on the fixing strip  20  in the simplest manner. 
         [0030]    As can be seen particularly in  FIG. 4  the stator support  5  can be attached to a transport security device. This transport security device is in the form of a sheet  9  fixed by bolts to the stator support  5 . The purpose of the transport security device is to keep the stator support  5  in its correct position during transport and assembly, without the stator support  5  coming into contact with a rotor  10  of the electric machine  2 . The rotor  10  of the electric machine  2  is fixed on the rotor hub  23 . 
         [0031]    From  FIG. 5  it can be seen that the stator support  5  of the electric machine  2  has at least one integrated cooling duct  11  of a cooling system of the electric machine  2 . The cooling duct  11  runs within the stator support  5  made, for example, as a casting. As can be seen particularly in  FIGS. 5 and 6 , the stator support  5  has a coolant connection for the cooling ducts  11  provided in the stator support. The coolant connection is fixed on the stator support  5  by a holding gland  12 . In this way the connection pipes  13  are connected to the cooling ducts  11  for the supply of coolant. For example, the coolant used can be water. 
         [0032]      FIG. 6  makes it clear that the holding gland  12  for fixing the coolant connection is held tight by two fixing screws  14 . If the fixing screws  14  are loosened, the connection pipes  13  can be rotated to a desired position. In this way the connecting pipes  13  can be adapted to specific, previously positioned lines. 
         [0033]    To vent the cooling system a main bearing point  15  of the stator support  5  can preferably be used. For this, a venting screw  22  can close off an opening of the main bearing point  15 . By screwing out the venting screw  22  as necessary, the cooling system can be vented. The venting screw  22  can be seen in  FIG. 1  in particular. 
         [0034]    On the stator support  5  there is also fixed an electric current terminal box  16 . Into this terminal box  16  run the three electric leads  17  connected to the respective coils  18  between the rotor  10  and the stator support  5  of the electric machine  2 , as shown in particular in  FIG. 4 . Among other things,  FIG. 5  shows a current rail  19  in which the leads  17  run, the current rail  19  extending along the outside of the stator support  5 . 
         [0035]    In addition a temperature sensor connection  20 , for example a so-termed NTC plug, is provided on the stator support  5 . The temperature sensor connection  20  is arranged on the outside circumference of the stator support  5 . 
         [0036]    Thus, an electric machine  2  with a compact and integrally formed stator support  5  is created, in which all the connections and interfaces required for operation are brought together. 
       INDEXES 
       [0000]    
       
           1  Clutch fork 
           2  Electric machine 
           3  Transmission housing 
           4  Hybrid housing 
           5  Stator support 
           6  Flange collar 
           7  Through-bore 
           8  Cut-out 
           9  Sheet 
           10  Rotor 
           11  Cooling duct 
           12  Holding gland 
           13  Connection pipes 
           14  Fixing screws 
           15  Main bearing point 
           16  Electric current terminal box 
           17  Leads 
           18  Coils 
           19  Current rail 
           20  Temperature sensor connection 
           21  Fixing strip 
           22  Venting screw 
           23  Rotor hub

Technology Category: h