Abstract:
A transmission ( 8 ) for a motor vehicle ( 2 ) with a housing ( 26 ) and a shifting apparatus arranged therein and with an electromechanical transmission actuator ( 24 ) with a first electric motor ( 32 ) for exercising a selection motion of the shifting device with a second electric motor ( 34 ) for exercising a shifting motion of the shifting apparatus and with a control unit ( 22 ) for receiving sensor signals, for processing the sensor signals and for emitting control signals to the electric motors ( 32, 34 ) the axis of rotation of the first electric motor ( 32 ) and the axis of rotation of the second electric motor ( 34 ) lie parallel to each other.

Description:
This application is a national stage completion of PCT/EP02/09626 filed Aug. 29, 2002 which claims priority from German Application Ser. No. 101 43 325.5 filed Sep. 5. 2001. 
     FIELD OF THE INVENTION 
     The invention concerns an electromechanical transmission actuator and a transmission outfitted with an actuator of this type. 
     BACKGROUND OF THE INVENTION 
     Motor vehicles with automated gear boxes have been present on the market for a long time. Preferred use areas are motor vehicles in commercial use such as transporters and trucks. Passenger cars with sports applications or small cars have been increasingly outfitted with such transmissions in the recent past. The goal is to free the driver from shifting gears and generally to make a more comfortable and safe operation possible. Motor vehicles with such transmissions usually have two pedals as accelerator and brake. The clutch pedal can be dispensed with. A controller is available in the motor vehicle for selecting the mode of operation. Here an automatic mode, a manual shifting mode and reverse gear can be selected. If the automatic mode is selected, the gear ratio adaptation takes place automatically. Various solutions for automating the gear box exist in the commercial vehicle area. Hence there are different variants, such as, for example, pneumatic, hydraulic or purely electric systems. Which variant is selected basically depends upon the class of motor vehicles and the types of energy available in these vehicles. Furthermore, the power requirement of the actuators used is an important parameter. Pneumatic or hydraulic cylinders or electric motors which drive the selection and shifting apparatus are used as actuators depending upon the system. Actuators, which are driven by electric motors represent especially economical constructions. 
     There has long been a need with motor vehicle transmissions to continue to use an existing mechanical transmission that is shifted manually with an automatic, electromechanical transmission actuator. Electromechanical transmission actuators for shifting a motor vehicle transmission are known in many ways. Here a transmission is used, which is either developed together with the transmission actuator or has the adaptation elements that must be provided on the transmission for interacting with the transmission actuator. 
     Such a transmission actuator is known by way of example from European Patent 0 377 848 B1. There an electromechanical transmission actuator is described which has two axes of motion arranged perpendicular to each other. An individual shift finger is guided by two electric motors on the axes of motion. Moreover, the shift finger moved by the first electric motor engages with a first axis of motion into respectively an opening in the various shifter rods arranged parallel alongside one another. The shifter rod is moved by the second electric motor in its long axis by motion of the shift finger on the second axis of motion for shifting a shifting package connected respectively with a shifter rod. The mechanism of motion of the shift finger in two axes of motion arranged perpendicular toward each other indeed corresponds to the selection and shifting specification on the basis of the manual shifting diagram as well as of the selection and the displacement of the respective shifter rod, but it also requires considerable structural space on the other hand. Even the number of components required for the transmission actuator is high. 
     The invention is based upon the objective of diminishing the number of components and diminishing the structural space required with a transmission actuator. 
     SUMMARY OF THE INVENTION 
     An electromechanical transmission actuator of the invention has a first electric motor to exercise a selection motion of a shifting device in a transmission housing of a motor vehicle transmission, and it has a second electric motor to exercise a shifting motion of the shifting device. Sensor signals are received, processes and emitted as control signals to the electric motors in a sensor unit. The control unit can be wholly or partially integrated into the transmission actuator or also be constructed as an external control apparatus. The axis of rotation of the first electric motor and the axis of rotation of the second electric motor lie parallel to each other, which significantly reduces the necessary space required. The use of as many identical parts as possible, such as electric motors, recirculating ball screws or ball nuts for example, enable parallel allocation to one another. In an advantageous refinement, the transmission actuator includes a housing that is mounted on the transmission housing. It is, moreover, precisely mounted in such a way that a manual shifting module is arranged on the transmission housing. In this way, a continued use of a previously manually shifted transmission is also then possible as a shifted transmission automated with a transmission actuator without having to alter the transmission itself, indeed if need be, without having to remove the transmission from the motor vehicle. The flange surface between the transmission actuator and the transmission housing remains unchanged. In another advantageous refinement, the transmission actuator includes a housing that is integrated into the transmission housing. In this way, screwing the transmission actuator outside on the transmission housing and processing tight surfaces of the transmission actuator toward the outside is dispensed with. The housing is preferably made of sheet steel or pressure die cast aluminum. In an especially advantageous design, the first electric motor and the second electric motor are arranged, side by side, on a common side of the housing of the transmission actuator. In a further refinement, the first electric motor and the second motor are arranged on two sides of the housing of the transmission actuator lying opposite to each other. The electric motors are screwed to the housing on their front faces and sealed off from the housing on the flange surface. Each electric motor possesses an external plug contact through which signals are exchanged and voltage supply is assured. When using flattened motors, an especially small transmission actuator can be created by corresponding from the mounting position by twisting of the motor into the mounting position, as is necessary in certain mounting positions. Brushless servomotors, direct current motors, alternating current motors or stepping motors can be used as electric motors. Recirculating ball screws are used in order to use the rotary motion of the electric motors into a linear motion. In one design, one recirculating ball screw with a small incline each is provided for the selection motion and the shifting motion, which is respectively driven directly by an electric motor. In another design, one recirculating ball screw each with a large inclination is provided for the selection motion and the shifting motion, which is respectively driven by one of the electric motors through a gear reduction. Here bevel gears, spur gear, combinations of bevel gear and spur gear transmissions, worm drives or even lever transmissions are used. A thread, a spindle or a threaded spindle and a nut corresponding thereto can also be used as an alternative to the recirculating ball screw and the ball nut movable thereupon. 
     In one refinement of the invention, a ball nut is provided on the recirculating ball screw for the shifting motion which is arranged in a control cylinder between two spring apparatuses which act in the direction of motion of the recirculating ball screw, and whose motion travels along the recirculating ball screw to the control cylinder in the direction of motion of the recirculating ball screw. When the recirculating ball screw rotates about its axis for the shifting motion, then the ball nut situated upon it moves in an axial direction and at the same time compresses the spring apparatus. The spring apparatus is for reasons of construction space constructed as a package of cup springs. When space permits, other types of springs are also possible, such as spiral springs in pulling or pressing construction, leaf springs, air springs, magnetic springs or plastic springs. These spring packages are used as energy storage mechanisms and are supposed to prevent a possible overstress of transmission shifting or of the drive unit with the electric motor, as well as enable a rapid shifting through the sliding sleeve after reaching the synchronization point. To brace the torque introduced into the recirculating ball screw, a screw or a pin is used, which is axially movable inside the control cylinder, but which prevents a relative rotation of the ball nut in relation the control cylinder. The ball nut, the spring package and the torque bracing are incorporated into the control cylinder. The axial motion of the control cylinder translated in one refinement, for example through a dowel pin or a ball-cylinder pairing, wherewith the control cylinder is connected with a shift lever and a shift finger, into a shifting motion of the shifting device perpendicular to the motion of the control cylinder running along the recirculating ball screw, for example a single selection and shifting shaft. A rotation of the shifting shaft and shift finger toward each other can be prevented by a force or form-locking connection, for example by a clamping pin. If the recirculating ball screw is placed into a rotary motion for the selection motion through the associated electric motor, then the ball nut is axially displaced on the recirculating ball screw. The selection finger is, for example, connected form-locking or force-locking with the ball nut and thus secured against rotation. Moreover, the selecting finger and the ball nut can comprise one component. The selecting finger can be axially secured against displacement relative toward the ball nut through a securing ring. The torque bracing can take place through an axial guiding of the selecting finger in the housing of the transmission actuator. In an advantageous refinement, the power dimensioning of the electric motor is provided with smaller dimensions for exercising the selection motion than the power dimensioning of the electric motor for exercising the shifting motion. The drive output of the electric motor can be variously designed since generally smaller forces must be applied for selecting an alley than, for example, for shifting downward from second into first gear. One design has additional bracing devices, which mount the electric motor on the transmission housing. They reduce the vibration accelerations occurring on the ends of the electric motors. The exact position and shape of the bracing sheet as well as the lashing of the electric motor onto the supporting sheet results from an examination of the excitation frequency of the transmission actuator. A restriction of the maximum acceleration enables a significantly longer and more secure operation of the overall system. In one refinement, a cross coupling is provided between the shaft of the motor and the recirculating ball screw. Through cross couplings or even through another force or form-locking coupling, such as in particular a multiple edge or polygonal profile or a slip coupling, an axle offset between the torque shaft of the electric motor and the recirculating ball screw can be equalized. The axial forces arising in the recirculating ball screw can be intercepted by mounting the recirculating ball screw in the housing of the transmission actuator and are not transmitted to the torque shaft of the electric motor. In another refinement, the recirculating ball screw is the torque shaft of the electric motor. One design has a ventilation apparatus in the transmission actuator, which at the same time guarantees the ventilation of the housing of the transmission actuator and the transmission housing. The arrangement is undertaken in such a way that the ventilation apparatus is not exposed to oil spray or other impairments. Integral or external sensors can be used to establish the current position of the shift finger. In one design, position sensors are provided on the surface of the housing of the transmission actuator, which interact without contact with a magnet on each of the recirculating ball screws. The external sensors likewise possess external plug contacts through which voltage supply and signal exchange is completed. The sensor signals are processed further in the control unit. 
     When operating automated transmissions, it is important to know exactly the position of the shift forks and engaging the individual gear steps at each point in time. The positions of shift rails of the shifting apparatus can be measured absolutely and thus an engagement of a gear can be recognized. If a position measurement is undertaken through relative sensors, then an adjustment of the sensors relative to the shifting apparatus is necessary after a certain number of shifting processes. In order to prevent the influences of a series scattering in the shifting apparatus and to guarantee functional safety, tolerance restrictions in relation to tolerances allowed with a non-automated transmission are necessary. 
     The shifting apparatus has reference shifters in an advantageous construction, which establish the defined absolute positions of the selection and operating shafts and which emit signals only when this defined absolute position is reached. The electric motor has an incremental transmitter that forwards the increment for a traversed rotation angle of the electric motor in a direction of rotation to a control unity in which a current measuring device is provided in an H-circuit. The incremental transmitter does not issue any absolute position, but only increments per path traversed and a direction of rotation of the electric motor. An absolute position signal is calculated on the basis of the path increments of the incremental transmitter. This calculation is continually adjusted with known position points. The current measuring device measures the current taken up by the electric motor. A calculated absolute position of the element can be ascertained in the control unit on the basis of the current course measured. This calculated absolute position is adjusted with the defined absolute position upon reaching the reference shifting. A reference shifter is, likewise, provided for adjusting the absolute position for the electric motor for the selection motion. If a signal is received from this reference shifter, then the defined absolute position of the element moved by this electric motor is known. The current absolute position is then compared with this defined absolute position and corrected if need be. In an advantageous construction, the reference shifter for the electric motor for the selection motion in a shifting diagram of the gear shift is arranged in the region between the shifting path of the reverse gear and the first adjacent shifting path for forward gears. If the calculated absolute position is lost, for example in connection with a reset while traveling, then it is possible to infer the resulting direction of travel region of the transmission when sweeping over the reference shifter thus arranged on the basis of the current direction of rotation. In one design, the reference shifters for the electric motor for the shifting motion lie on mechanically determined end positions of the moved elements, especially the selector shaft or shifting rails, which correspond to a completely engaged gear, thus to the position in which shifting is concluded. Without serious restrictions of the shifting facility in a transmission, especially in the case of an automatic transmission, the shifting sequence can be monitored, the engagement of the gears can be recognized and reaching the end position can be established with a sensor. 
     An especially advantageous design illustrates a transmission with a transmission actuator of the invention, which is an automated gear shift operating according to a shifting logic. Basically the transmission actuator of the invention can also be used for gear shifts in which the shifting signals are generated manually by the motor vehicle operator and are then forwarded to the control unit. Hence the transmission is only shifted when the driver initiates the shifting. The shifting apparatus in the transmission shifted by the transmission actuator preferably includes combined selection or selector shaft upon which the transmission actuator acts by rotation of the combined selection and shifter shaft and acts upon the transmission actuator by axial displacement of the combined selection and shifter shaft as a shifting process. 
     The shifting apparatus is then constructed as a one rail shift in which the selection and shifter shaft activated by the electric motors engages directly on the shifting elements. The selection and shifter shaft is fixed in the end position of the gears as well as in the neutral position by locking elements. 
     A multiple rail shift with a selecting and a shifting element can be provided in the form of a central selection and shifter shaft in the case of the shifting apparatus of the gear shift which has at least one electric motor each for the shifting motion and for the selecting motion. This central selection and shifter shaft engages on several rails which respectively activate one shifting element. All rails are fixed in the end positions of the gears as well as in the neutral position by locking elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described, by way of example, with reference to the accompanying drawings in which: 
         FIG. 1  is a schematic representation of a transmission in the motor vehicle; 
         FIG. 2  illustrates the arrangement of a transmission actuator on the transmission; 
         FIG. 3  illustrates a transmission actuator closed; 
         FIG. 4  illustrates a transmission actuator according to  FIG. 3  partially opened; 
         FIG. 5  illustrates the transmission actuator in plan view in partial section; 
         FIG. 6  illustrates the transmission actuator in elevation in partial section; 
         FIG. 7  illustrates a transmission actuator with four motors; 
         FIG. 8  illustrates an H shift in the control unit; 
         FIG. 9  illustrates a shifting diagram; and 
         FIG. 10  illustrates a current course during a shifting. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates a schematic representation of a motor vehicle  2  with a drive motor  4  which acts upon a transmission  8  through a friction clutch  6 . The transmission  8  is connected with a differential  12  through an output shaft  10 , which drives a motor vehicle wheel  16  through one half axle  14  each. The friction clutch  6  is activated by an actuator  18  which is connected with a control unit  22  through a signal line  20 . The transmission  8  is activated by a transmission actuator  24  which is arranged on a housing  26  of the transmission and which is connected with the control unit  22  by a line  28 . 
     The transmission actuator  24  in an externally arranged housing  30  is mounted on the transmission housing  26  of the transmission  8  in  FIG. 2 . A first electric motor  32  and a second electric motor  34  lying beneath it, in this view, are arranged alongside each other on one side of the housing  30 . A bracing sheet  36  embraces the two electric motors  32  and  34  and is fastened outside on the transmission housing  26 . 
     In  FIG. 3 , the transmission actuator  24  is represented detached from a transmission. The electric motor  32  and the electric motor  34  are arranged alongside each other on one side on the housing  30 . The electric motor  32 , competent for executing the selecting motion, has a smaller dimensioning than electric motor  34  which is competent for implementing the shifting motion. Each electric motor  32 ,  34  has a plug connection  38 ,  40  which serve for signal transmission and power transmission. An external position sensor  42  registers the displacement of a ball nut  44  of a recirculating ball screw  46  which is competent for the selection motion (see  FIG. 4 ). A further external position sensor  48  registers the displacement of a control cylinder  50  on a recirculating ball screw  52  which is competent for the shifting motion. The position sensors  42 ,  48  have plug connections  54 ,  56  which serve to transmit signals. A ventilator  58  is installed on the side of the housing  30  through which the interior of the housing  30  of the transmission actuator  24  as well as the transmission housing  26  is ventilated. 
       FIG. 4  illustrates the transmission actuator  24 , according to  FIG. 3 , in a partially opened representation that makes possible a detailed description of the functional features of the transmission actuator  24 . The electric motor  32  drives the recirculating ball screw  46  that is mounted in two bearings  60  and  62 . The ball nut  44  is axially displaced on the recirculating ball screw  46  when the electric motor  32  is rotated, whereby the current position of the ball nut  44  is transmitted over a magnet  64  mounted on an extension arm of the ball nut  44  to the position sensor  42 . A shift finger  66  is provided on the ball nut  44  which is constructed circular on its depicted lower end. The shift finger  66  engages into a selection and shifter shaft  68  of the transmission  8  with this circular part which extends at right angles toward the axis of rotation of the recirculating ball screw  46 . The shift finger  66  rotates the selection and shifter shaft  68  about its axis of rotation through an axial motion of the ball nut  44  along the recirculating ball screw  46  and in this way executes a selection motion in the shifting apparatus. The larger electric motor  34  drives the recirculating ball screw  52  which is mounted in two bearings  70  and  72 . A ball nut  74  is axially displaced on the recirculating ball screw  52  when the electric motor  34  rotates. Moreover, the ball nut  74  first compresses either the cup springs in a spring package  76  or in a spring package  78  depending upon the direction of rotation which are both provided each on one side of the ball nut  74  inside the control cylinder  50 . The current position of the control cylinder  50  is transmitted to the position sensor  48  through a magnet  80  mounted on the control cylinder  50 . The control cylinder  50  is connected with one end of a deflection lever  84  through a dowel pin  82  ( FIG. 6 ) which transmits the motion of the control cylinder  50 . The shift finger  66  engages on the selection and shifter shaft  68  with its end. The axial motion of the ball nut  74  is deflected by the deflection lever  84  in such a way that the selection and shifter shaft  68  arranged perpendicular to the recirculating ball screw  52  is displaced along its axis of rotation and in this way conducts a shifting motion in the shifting apparatus. The deflection lever  84  is secured by a clamping pin  88  onto torque shaft  90  against a relative rotation on the torque shaft  90 . The torque shaft  90  is mounted in a bearing  92  ( FIG. 6 ) in the transmission housing  26  and in a bearing  94  in the housing  30  of the transmission actuator  24 . In this way, the planned mounting of the manual shifting apparatus in the transmission housing  26  can be undertaken. 
       FIG. 5  illustrates the transmission actuator  24  in a partial section views in which the transmission actuator  24  is viewed  24  from below. The electric motors  32  and  34  of different sizes are represented closed in a plan view while the sectioned region of the recirculating ball screws  46  and  52  depicts the spring packages  76  and  78  opened on both sides of the ball nut  74  on the ball spindle  52 . The cup springs in the spring packages  76  and  78  first absorb the motion of the ball nut  74  and, if the situation in the shifting permits, the motion is transmitted to the shifting apparatus through the control cylinder  50 . The rotary motion of the electric motors  32  and  34  are transmitted to the recirculating ball screws  46  and  52  from the axes of rotation through cross couplings  96  and  98 . In this way, the torque between the components is transmitted despite a possible axle offset between the torque shaft of the electric motor and the recirculating ball screw. The ventilator  58  is arranged in the housing  30  of the transmission actuator  24 . 
       FIG. 6  depicts the transmission actuator  24  in a partial section side view in which a section through the recirculating ball screw  52  is shown which is competent for the shifting motion. Identical components, as in other parts of the drawings, have the same reference numbers. When the recirculating ball screw  52  is rotated by the electric motor  34 , the ball nut  74  is moved from right to left on the drawing plane. Moreover, the spring packages  76  or  78  are first compressed and the control cylinder  50  is moved through this. The ball nut  74  is secured against a rotation relative to the control cylinder  50  during its axial motion by a screw  100  or a dowel pin which is fastened in the control cylinder  50  and whose tip  102  engages into an axial slot  104  inside the ball nut  74 . The slot allows an axial motion of the ball nut  74  but impedes its rotation. The mounting of the torque shaft  90  in bearings  92  and  94  can be clearly recognized in  FIG. 6 . The connection between the control cylinder  50  and the deflection lever  84 , which is guaranteed by the dowel pin  82 , likewise, is recognizable. The shift finger  66  projects downward out of the transmission actuator  24  to enter into connection with the not depicted selection and shifter shaft  68 . A shift finger  86  on the deflection lever  84  projects even further downward out of the transmission actuator and engages laterally on the selection and shifter shaft  68 . The magnet  64  on the ball nut  44  interacts with the position sensor  42  for position recognition, while the magnet  80  on control cylinder  50  interacts with the position sensor  48 . 
       FIG. 7  illustrates an arrangement of the transmission actuator  24  in which two additional electric motors  106  and  108  are installed on the housing  30  in addition to motors  32  and  34 . The housing  30  is basically constructed such that either two electric motors lying alongside each other are provided on it as in  FIG. 3  or four electric motors are provided as in  FIG. 7 . Of the four electric motors  32 ,  34 ,  106 ,  108 , two electric motors  32  and  106  or  34  and  108 , respectively, engage on the same recirculating ball screw  46  or  52 . The electric motors can be configured smaller with identical activation force, or the activation forces for the shifting elements can be increased when using identical electric motors through the engagement of the respective two electric motors. Plug connections  110  and  112  are provided on the electric motors  106  and  108  just as on the electric motors  32  and  34  for transmitting signals and current supply. 
       FIG. 8  illustrates an H-bridge  202  in a control unit  204 , a voltage source  206 , an electric motor  208  and a current measuring device  210 . The current measuring device  210  makes an indirect measurement of the torque of the electric motor  208  possible. 
       FIG. 9  illustrates a shifting diagram  212  for a six-gear gear shift. A position  220  for a reference shifter is provided in a selection path  214  between a shifting path  216  for the reverse gear and a shifting path  218  for the first and second reverse gear which can be swept over in the event of loss of the calculated absolute position. 
       FIG. 10  illustrates a typical curve of the current I over time t measured in the current measuring device as it is basically measured when shifting into any desired gear. The current lies on a constant level in a first phase from t — 0 to t — 1. In the synchronizing phase from t — 1 to t — 2, the current rises when the clutch sleeve strikes upon associated elements of the gear wheel to be shifted in the shifting apparatus until the synchronized running of the components is attained. The current drops again in the phase from t — 3 to t — 4 upon unblocking the synchronization while the clutch sleeve is moved in the direction of the position of reaching the gear to be shifted. If this end position of the shifting rails or shifter shaft fixed by locking elements is reached, the current I in the electric motor rises again in the phase from t — 5 to t — 6. If the motor  208  shuts off, for example by reaching a reference shifter, then the shifting rails or shifter shaft remains in the end position fixed by locking elements. If the shifting element  50  provided with a shifting elasticity  76 ,  78  is used in a transmission actuator  24  of the shifting apparatus ( FIG. 4 ), then the clamped shifting elasticity  76 ,  78  is released and at the same time pushes the non self-inhibiting recirculating ball screw  52  back. The electric motor  208 ,  34 ,  108  is therewith situated in a defined absolute position and this absolute position can be compared with the calculated absolute position. The calculated absolute position can then be equalized, if need be. This equalization is conducted for each gear in each shift. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 Reference numbers 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 2 
                 Motor vehicle 
               
               
                 4 
                 Drive motor 
               
               
                 6 
                 Friction clutch 
               
               
                 8 
                 Transmission 
               
               
                 10 
                 Output shaft 
               
               
                 12 
                 Differential 
               
               
                 14 
                 Half axle 
               
               
                 16 
                 Motor vehicle wheel 
               
               
                 18 
                 Actuator 
               
               
                 20 
                 Signal line 
               
               
                 22 
                 Control unit 
               
               
                 24 
                 Transmission actuator 
               
               
                 26 
                 Housing 
               
               
                 28 
                 Line 
               
               
                 30 
                 Housing 
               
               
                 32 
                 Electric motor 
               
               
                 34 
                 Electric motor 
               
               
                 36 
                 Bracing sheet 
               
               
                 38 
                 Plug connection 
               
               
                 40 
                 Plug connection 
               
               
                 42 
                 Position sensor 
               
               
                 44 
                 Ball nut 
               
               
                 46 
                 Recirculating ball screw 
               
               
                 48 
                 Position sensor 
               
               
                 50 
                 Control cylinder 
               
               
                 52 
                 Recirculating ball screw 
               
               
                 54 
                 Plug connection 
               
               
                 56 
                 Plug connection 
               
               
                 58 
                 Ventilator 
               
               
                 60 
                 Bearing 
               
               
                 62 
                 Bearing 
               
               
                 64 
                 Magnet 
               
               
                 66 
                 Shift finger 
               
               
                 68 
                 Selection and shifting shaft 
               
               
                 70 
                 Bearing 
               
               
                 72 
                 Bearing 
               
               
                 74 
                 Ball nut 
               
               
                 76 
                 Spring package 
               
               
                 78 
                 Spring package 
               
               
                 80 
                 Magnet 
               
               
                 82 
                 Dowel pin 
               
               
                 84 
                 Deflection lever 
               
               
                 86 
                 Shift finger 
               
               
                 88 
                 Clamping pin 
               
               
                 90 
                 Torque shaft 
               
               
                 92 
                 Bearing 
               
               
                 94 
                 Bearing 
               
               
                 96 
                 Cross coupling 
               
               
                 98 
                 Cross coupling 
               
               
                 100 
                 Screw 
               
               
                 102 
                 Tip 
               
               
                 104 
                 Slot 
               
               
                 106 
                 Electric motor 
               
               
                 108 
                 Electric motor 
               
               
                 110 
                 Plug connection 
               
               
                 112 
                 Plug connection 
               
               
                 202 
                 H bridge 
               
               
                 204 
                 Control unit 
               
               
                 206 
                 Voltage source 
               
               
                 208 
                 Electric motor 
               
               
                 210 
                 Current measuring device 
               
               
                 212 
                 Shifting diagram 
               
               
                 214 
                 Selection path 
               
               
                 216 
                 Shifting path 
               
               
                 218 
                 Shifting path 
               
               
                 220 
                 Position