Abstract:
A torque transmission unit which has a first centrifugal mass that can be non-rotatably associated with an internal combustion engine and a second centrifugal mass that is connected downstream of the first mass and can be associated with a transmission. The second centrifugal mass has a rotor of an electric machine for transmitting a torque that can be electrically generated to the second centrifugal mass and a centrifugal force pendulum for reducing torsional vibrations.

Description:
[0001]    This application is a Continuation PCT/EP2009/001204 filed Aug. 27, 2009, which in turn claims the priority of DE 10 2008 046 790.1 filed Sep. 11, 2008, the priority of both applications is hereby claimed and both applications are incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a torque transmission unit with a first centrifugal mass assignable to an internal combustion engine so as to rotate therewith, and a second centrifugal mass assignable to a gear unit and connected downstream of the first centrifugal mass. 
       BACKGROUND OF THE INVENTION 
       [0003]    Torque transmissions units are known and serve for transmitting torques between the internal combustion engine and the gear unit. For reducing the rotary vibrations occurring during the transmission, the centrifugal masses can be assigned so as to be rotatable relative to each other. Moreover, it is known for reducing the rotary vibrations to provide a centrifugal force pendulum device. German patent application publication DE 10 2006 028 556 A1 discloses a torque transmission unit with a rotary vibration damper and a centrifugal force pendulum device which is arranged in the axial direction between an energy storage device and a counter pressure plate of a clutch. In another embodiment, it is shown that the centrifugal force pendulum device may also be arranged radially within the energy-storing unit. 
       SUMMARY OF THE INVENTION 
       [0004]    It is the object of the invention to make available an improved torque transmission unit, particularly for hybrid applications, in which an internal combustion engine and an electric motor are provided. 
         [0005]    In a torque transmission unit, the object is met by a first centrifugal mass assignable non-rotatably to an internal combustion engine and a second centrifugal mass connected downstream of the first centrifugal mass and assignable to a gear unit, in that the second centrifugal mass has a rotor of an electric machine for transmitting an electrically producible torque to the second centrifugal mass and a centrifugal force pendulum device for reducing rotary vibrations. The first centrifugal mass can be driven by means of the internal combustion engine and the second centrifugal mass can be driven via the first centrifugal mass, wherein advantageously torques are transmittable between the internal combustion engine and the gear unit. Advantageously, an electrical drive or decelerating moment can additionally be transmitted by means of the electric machine to the second centrifugal mass. This torque can be transmitted to the gear unit and/or the internal combustion engine, for example, for driving or decelerating a motor vehicle equipped with the torque transmission unit. In addition, it is possible to start the internal combustion engine by means of the electrical machine. The electrical machine may be an electric motor, for example, a synchronized or asynchronized machine, a generator, for example, a starter generator. Advantageously, by means of the torque transmission unit, a parallel hybrid arrangement can be realized for the motor vehicle equipped with the parallel hybrid arrangement. In this connection, the centrifugal force pendulum device provided can reduce or especially eliminate the rotary vibrations occurring during the operation of the internal combustion engine or during transmitting torques between the internal combustion and the gear unit. The centrifugal force pendulum device can be constructed as disclosed in DE 10 2006 028 556 A1. This document, especially the figures and the corresponding description of the figures, are incorporated into this application by reference. The reduction of rotary vibrations can be understood to mean a vibration isolation of rotary vibrations occurring during the operation of the internal combustion engine, an elimination and/or damping of the rotary vibrations. The second centrifugal mass can advantageously be assigned to the gear unit in such a way that between the gear unit and the second centrifugal mass torques are transmittable, for example, the torques which can be produced during operation of the internal combustion engine and/or the electric machine. 
         [0006]    In one embodiment of the torque transmission unit, it is provided that the first centrifugal mass and the second centrifugal mass are assignable or assigned by means of an energy storage device so as to be rotatable relative to each other. Advantageously, the first centrifugal mass, the intermediately arranged energy storage device and the second centrifugal mass can dampen rotary vibrations according to the principle of a so called dual mass flywheel. 
         [0007]    In another embodiment of the torque transmission unit, it is provided that between the first centrifugal mass and the second centrifugal mass, a separating clutch is connected. 
         [0008]    Advantageously, an energy flux or a transmission of a torque between the internal combustion engine and the second centrifugal mass can optionally be separated or established by means of the separating clutch. When the separating clutch is closed, a torque transmission between the internal combustion engine and the gear unit is possible. When the separating clutch is open, the internal combustion engine runs freely, i.e., it can be switched off, wherein advantageously the second centrifugal mass still either runs freely or can be driven or decelerated by means of the electric machine. It is conceivable that the separating clutch has a portion of the first centrifugal mass, i.e., when the clutch is open, the first centrifugal mass is assigned only partially to the internal combustion engine. It is conceivable in this connection to dimension the first centrifugal mass which remains when the separating clutch is open in such a way that the internal combustion engine is not capable of operating, i.e. the internal combustion engine motor always stands still when the separating clutch is open. This may be useful especially for restarting the internal combustion engine because of the significantly reduced motor centrifugal mass, i.e., the portion of the first centrifugal mass remaining in front of the separating clutch result in particularly quick restarting times of the combustion engine. 
         [0009]    In another embodiment of the torque transmission device it is provided that by way of the energy storage device, the second centrifugal mass is assigned a third centrifugal mass rotatable relative thereto for storing and releasing energy. Advantageously, according to the principle of a dual mass flywheel, rotary vibrations can be dampened. 
         [0010]    In accordance with another embodiment of the torque transmission unit, it is provided that by means of the separating clutch the third centrifugal mass can be assigned to the first centrifugal mass or separated therefrom. Advantageously, when the separating clutch is closed, the third centrifugal mass can act as part of the first centrifugal mass, for example, in order to keep the internal combustion engine ready for operation. The total centrifugal mass resulting from the third centrifugal mass and the first centrifugal mass is assigned via the energy storage device to the second centrifugal mass so as to be rotatable relative thereto. Advantageously, when the separating clutch is closed, a rotary vibration damper results in accordance with the principle of a two mass flywheel. The energy storage device can have, for example, for coupling, for energy storage and dampening of rotary vibrations between the first centrifugal mass coupled to the third centrifugal mass and the second centrifugal mass at least one or a plurality of arc springs. 
         [0011]    In accordance with another embodiment of the torque transmission unit, it is provided that the rotor of the electric machine includes the centrifugal force pendulum device. Advantageously, the centrifugal force pendulum device can be arranged via the rotor to the second centrifugal mass and can reduce the rotary vibrations when transmitting torques. 
         [0012]    In another embodiment of the torque transmission unit it is provided that the centrifugal force pendulum device is arranged radially outside of the intermediate shaft of the second centrifugal mass. The arising torques can be transmitted by means of the intermediate shaft. Advantageously, the centrifugal force pendulum device can be arranged as far radially outwardly of the intermediate shaft as possible, so that centrifugal forces acting on the centrifugal force pendulum device are especially high, wherein this advantageously results in a particularly good action of the centrifugal force pendulum device. 
         [0013]    In another embodiment of the torque transmission unit, it is provided that at least one element of the following group is connected downstream of the second centrifugal mass: Start-up clutch, a manual shift gear unit, for example, also automatic, a step-by-step automatic gear unit, a step automatic gear unit with converter, a double clutch gear unit, a CVT gear unit. The start-up clutch and/or the separating clutch may be constructed as conventional clutches or as self-readjusting clutches (SAC). Advantageously, a motor vehicle equipped with the torque transmission unit can start in the known manner by means of the start-up clutch and facilitate a synchronization of gears of a downstream standard transmission. Advantageously, several hybrid arrangements with a start-up clutch and a standard transmission and/or a double clutch gear unit, a stepped automatic gear unit and/or a step automatic gear unit with converter, or a CVT gear unit are possible. 
         [0014]    In another embodiment of the torque transmission unit, it is provided that the centrifugal force pendulum device is arranged axially adjacent to a rigid flywheel, particularly a counter pressure plate, of the start-up clutch. Advantageously, a structural space remaining next to the counter pressure plate can be utilized. 
         [0015]    In another embodiment of the torque transmission unit it is provided that the centrifugal force pendulum device is arranged axially between the start-up clutch and the electric machine. Advantageously, a remaining axial structural space can be utilized between the electric machine and the start-up clutch for positioning the centrifugal force pendulum device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0016]    Further advantages, features and details result from the following description in which an embodiment is described in detail with reference to the drawing. Equal, similar and/or functionally equivalent parts are provided with the same reference numerals. In the drawing: 
           [0017]    The FIGURE shows a torque transmission unit with an electric machine in half section. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    The FIGURE shows a torque transmission unit  1  with a first centrifugal mass and a second centrifugal mass  5  downstream for the first centrifugal mass. The first centrifugal mass  3  is assignable non-rotationally to an internal combustion engine  7  indicated in the FIGURE by the reference numeral  7 , for example, by means of a flange  9 . The separating clutch  11  is assigned to the first centrifugal mass  3 . The separating clutch  11  is part of the first centrifugal mass  3  and has, for the non-rotating connection of the first centrifugal mass  3  with a third centrifugal mass  13 , clutch linings  15  and, for pressing-on of these, pressure plates  17  configured for this. The pressure plate  17 , or the separating clutch  11 , can be constructed so as to be hydraulically operated by means of a hydraulic operating device  19 . The third centrifugal mass  13  is assigned to the second centrifugal mass  5  in a rotatable manner relative to the latter by means of an energy storage device  21  for transmitting a torque. The third centrifugal mass  13  has, for surrounding the energy storage device  21 , two sheet metal parts  23 . By means of the sheet metal parts  23 , a grease reservoir  25  can be formed for arc springs  27  of the energy storage device  21 . Via the arc springs  27  of the energy storage device  21 , the third centrifugal mass  13  and the second centrifugal mass  5  are assigned to each other spring-loaded and rotatable relative to each other. When the separating clutch  11  is closed, a vibration capable system is obtained between the total centrifugal mass and the second centrifugal mass  5 , wherein the total centrifugal mass includes the first centrifugal mass  3  and the third centrifugal mass  13 . 
         [0019]    The second centrifugal mass  5  has a start-up flange  29  which is in engagement with the arc springs  27  of the energy storage device  21 . The start-up flange  29  is assigned non-rotatably to the second centrifugal mass  5  for transmitting a torque of a hub  31 . The hub  31 , in turn, is assigned non-rotatably by means of a toothing to an intermediate shaft  33  of the second centrifugal mass. The intermediate shaft  33  is supported by means of a first pilot bearing  37  in a crank shaft  39  of the internal combustion motor  7  and is supported by means of a second intermediate shaft bearing  57 . The intermediate shaft  33  has an intermediate flange  35  which non-rotatably couples the intermediate shaft  33  with a rotor  47  of an electric machine  49 , a centrifugal force pendulum device  51  as well as a counter pressure plate  53  of a start-up clutch  55 . The intermediate shaft bearing  57  is assigned by means of a bearing sheet  59  fixedly to a housing  61  of a housing  63  of the torque transmission unit  1 . For this purpose, the bearing sheet  59  can be fixedly assigned to the housing part  61  of the remaining housing  63  by means of a screw connection  65 . The gear unit input shaft  43  is supported via a pilot bearing  41  on the intermediate shaft  33 . 
         [0020]    The bearing sheet  59  is stepped and forms a partial housing for the separating clutch  11 , the energy storage device  21  as well as the hydraulic actuating device of the separating clutch  11 . Radially outside of a step  67  of the bearing sheet  59  of the housing  63 , i.e., outside of the partial housing of the separating clutch  11 , the rotor  47  of the electric machine  49  is arranged. Radially outside of the rotor  47  and within the housing  63  is arranged an exciter device  69  of the electric machine  49 . 
         [0021]    The centrifugal force pendulum device  51  is arranged axially between the rotor  47  of the electric machine  49  and the counter pressure plate  53  of the start-up clutch  55 . The terms axial and radial may refer to an axis of rotation  71  of the torque transmission unit  1 . The term axial may serve for describing a direction or parallel to the axis of rotation  71  of the torque transmission unit  1 . The centrifugal force pendulum device  51  is arranged adjacent to the electric machine  49  or to the rotor  47  of the electric machine  49  and adjacent to the counter pressure plate  53  of the start-up clutch  55  as well as radially outside of the intermediate shaft  33 . Alternatively, it is conceivable to assign the centrifugal force pendulum device  51  directly to the rotor  47  and/or the intermediate shaft  33  and/or counter pressure plate  53  of the start-up clutch  55 . 
         [0022]    The centrifugal force pendulum device  51  is arranged in an essentially greaseless space  73  and includes several pendulum masses  75 ,  77 . The pendulum masses  75 ,  77  are moveable, for example, by means of rollers mounted on a carrier flange  79  of the centrifugal force pendulum device  51 . The carrier flange  79  is part of the intermediate flange  35  and is assigned by the intermediate flange  35  non-rotatably to the intermediate shaft  33 , i.e., the second centrifugal mass  5 . The centrifugal force pendulum device  51  includes preferably several, for example four pendulum masses  75 ,  77 , or pendulum mass pairs which are uniformly distributed over the circumference of the carrier flange  79 . The centrifugal force pendulum device  51  may be constructed like the various centrifugal force pendulum devices which are disclosed in the German patent application publication DE 10 2006 028 556 A1. The centrifugal force pendulum device  51  may however also be constructed as other conventional centrifugal force pendulum devices. 
         [0023]    The start-up clutch  55  has a cover  81  and a counter pressure plate  85  which can be actuated by means of a disengaging device  83 . In this manner, by means of the start-up clutch  55  it is possible in a known manner to transmit a torque from the intermediate shaft  33  by means of clutch linings  87 , a clutch disk  89  and a clutch hub  91  to the gear unit input shaft  43  or to separate the gear unit input shaft  43  from the intermediate shaft  33 . 
         [0024]    When the separating clutch  11  is open and the start-up clutch  55  is closed, the electric machine  49  is non-rotatably assigned to the gear unit  45 , i.e., can be used, for example, for driving or decelerating, particularly for recuperation of the motor vehicle equipped with the torque transmission unit  1 . 
         [0025]    When the separating clutch  11  is open and the start-up clutch  55  is open, the internal combustion engine  7  as well as the electric machine  49  are entirely separated from the gear unit  45 , i.e., from the remaining drive train of the motor vehicle. This condition can be utilized, for example, when the motor vehicle stands still. A stand still of the motor vehicle is also possible when the separating clutch  11  is closed and the start-up clutch  55  is open, wherein the internal combustion engine  7  can be kept in operation, for example, in order to carry out a start-up procedure controlled or adjusted by the start-up clutch  55 . When the internal combustion engine  7  is standing still and the motor vehicle is driving, it is conceivable to start-up the internal combustion engine  7  by closing the start-up clutch  55 . 
         [0026]    When the separating clutch  11  is open and the start-up clutch  55  is closed, it is possible to let the internal combustion engine run freely, particularly to allow it to stand still. Advantageously, the internal combustion engine  7  can be started by closing the separating clutch  11 . This procedure can be reinforced by means of the electric machine  49  of the rotating energy of the second centrifugal mass  5  and/or by means of the motor vehicle which is in movement. In addition, it is conceivable to start the internal combustion engine  7  by means of the electric machine  49  with the separating clutch  11  being closed and the start-up clutch  55  being open. Furthermore, it is conceivable to charge a battery, not illustrated, or an energy storage device, particularly a capacitor of the motor vehicle for storing electrical energy, also in this state of operation, by way of the internal combustion engine, for instance when the motor vehicle stands still. 
         [0027]    The centrifugal masses  3 ,  5 ,  13  coupled to each other by means of the energy storage device  21  can form advantageously a vibration capable system according to the two-mass flywheel principle and can dampen rotary vibrations or can facilitate a vibration isolation of the internal combustion engine  7 . In addition, it is possible by means of the centrifugal force pendulum device  51  to carry out additional vibration isolation. The centrifugal force pendulum device  51  acts like an eliminator whose stiffness is advantageously influenced by the centrifugal force or is produced by the centrifugal force. Advantageous is a natural frequency of the centrifugal force pendulum device  51  proportional to a rotational frequency. This makes it advantageously possible to very efficiently counteract selected vibration levels by way of an appropriate adjustment of elimination characteristics of the centrifugal force pendulum device  51 . By using the additional centrifugal force pendulum device  51 , it is possible to omit or at least essentially omit, a slippage of the start-up clutch  55  for reaching a necessary isolation. 
         [0028]    In applications for hybrid drives as illustrated in  FIG. 1 , the centrifugal force pendulum device  51  may be placed advantageously before the counter pressure plate  53  of the start-up clutch  55 , forming a rigid flywheel. For this purpose, the centrifugal force pendulum device  51  may be fastened to the counter pressure plate  53 , the intermediate shaft  33  and/or to the rotor of the electric machine  49 . Advantageously, a ground isolation can additionally be implemented via the third centrifugal mass  13  assigned to the energy storage device  21 , wherein the third centrifugal mass  13  forms a clutch disk of the separating clutch  11 . 
         [0029]    Advantageously, is the additional mass of the centrifugal force pendulum device  51  is, when the separating clutch  11  is open, not assigned to the internal combustion engine  7 , wherein a remaining centrifugal mass of the internal combustion engine  7  becomes as small as possible, which facilitates a restart of the internal combustion engine  7  as quickly as possible. The mass inertia moment to be accelerated by the internal combustion engine  7  can advantageously be minimized. Advantageously, primary mass inertia moments are minimized. This low primary mass facilitates advantageously a low restarting time of the internal combustion engine. Advantageously, the first centrifugal mass  3  may form a rigid flywheel of the internal combustion engine  7 , the mass inertia of which is optimized. 
         [0030]    It is possible to achieve a hybrid drive for a vehicle, particularly motor vehicle, with an automated and/or partially automated gear shift unit, so called “Clutch-by-wire,” by mounting the additional separating clutch  11 . Advantageously, the required isolation requirements can be met by way of the energy storage device  21  and the centrifugal force pendulum device  51  together. 
         [0031]    Via a centrifugal wheel rigidly mounted on the crankshaft  39  or respectively the first centrifugal mass  3  and the separating clutch  11  attached to the centrifugal mass  3 , the clutch disk of the separating clutch  11 , i.e., the third centrifugal mass  13  is driven. This separating clutch  11  facilitates the separation of the internal combustion engine  7  from the gear unit  45 . Via the toothing of the hub  31 , the torque of the internal combustion engine  7  is transmitted via the intermediate shaft  33  onto the start-up clutch  55 . Additionally, as necessary, the existing electric machine  49  conducts another torque into the start-up clutch  55 . When the separating clutch  11  is open, wherein the internal combustion engine  7  may be standing still, the electric machine  49  can also independently drive the vehicle. By closing the separating clutch  11 , the idle internal combustion engine  7  can be restarted from the various driving situations by the electric machine  49 . The intermediate shaft  33  is supported in the crankshaft  39  by means of the first pilot bearing  37  and via an additional support or the bearing sheet  59  by means or the intermediate storage  57  on the housing part  61  of the housing  63 . The intermediate shaft  33  is arranged on a primary side of the start-up clutch  55  and is part of the second centrifugal mass  5 . The start-up clutch  55  may be subject to partial or fully automatic control and can be constructed conventional or as a self-readjusting clutch (SAC). 
         [0032]    A disengaging device of the separating clutch  11  can be constructed so as to be fixed on the housing. A support of the gear unit input shaft  43  can take place advantageously via the second pilot bearing  41  in the intermediate shaft  33 . 
         [0033]    The centrifugal force pendulum device  51  can be placed on the rotor  47  of the electric machine  49 , on the intermediate shaft  33  and/or in front of the rigid centrifugal wheel or counter pressure plate  53  of the start-up clutch  55 . Alternatively, it is conceivable to use as damper in the start-up clutch  55  also a two-mass flywheel or a dampened coupling disk. For the start-up clutch  55  and the separating clutch  11  conventional clutches or even self-readjusting clutches (SAC) can be used. For actuating the separating clutch  11  it is also possible to use the disengaging device which is fixedly attached to the cover. Advantageously, the centrifugal force pendulum device  51  can also be used if a subsequently arranged stepped automated gear unit is used with or without converter or a subsequently arranged double clutch gear unit. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
         
           
               1 . Torque transmission device 
               3 . First centrifugal mass 
               5 . Second centrifugal mass 
               7 . Combustion engine 
               9 . Flange 
               11 . Separating clutch 
               13 . Third centrifugal mass 
               15 . Clutch linings 
               17 . Pressure plate 
               19 . Hydraulic operating device 
               21 . Energy storage device 
               23 . Sheet metal parts 
               25 . Grease reservoir 
               27 . Arc springs 
               29 . Start-up flange 
               31 . Hub 
               33 . Intermediate shaft 
               35 . Intermediate flange 
               37 . First pilot bearing 
               39 . Crankshaft 
               41 . Second pilot bearing 
               43 . Gear unit input shaft 
               45 . Gear unit 
               47 . Rotor 
               49 . Electric machine 
               51 . Centrifugal force pendulum device 
               53 . Counter pressure plate 
               55 . Start-up clutch 
               57 . Intermediate shaft bearing 
               59 . Bearing sheet 
               61 . Housing part 
               63 . Housing 
               65 . Screw connection 
               67 . Step 
               69 . Exciter device 
               71  Axis of rotation 
               73 . Greaseless space 
               75 . Pendulum mass 
               77 . Pendulum mass 
               79 . Carrier flange 
               81 . Cover 
               83 . Disengaging device 
               85 . Counter pressure plate 
               87 . Clutch linings 
               89 . Clutch disk 
               91 . Clutch hub