Abstract:
The present invention relates to an adjustment drive, in particular for a vehicle, for driving a component, comprising a drive unit having comprises a first output shaft, wherein an output unit or an intermediate unit, which is disposed between the input unit and the output unit, can be adapted in a modular manner to the first output shaft.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an adjustment drive, in particular for a vehicle, for driving a component, having an input unit, which comprises a first output shaft. 
     In vehicles, especially in motor vehicles, the operation of vehicle components and convenience for the occupants are increasingly being simplified by automating the vehicle components. For this purpose, there is a need for adjustment drives which can be used for adjustment tasks, locking and unlocking tasks and positioning tasks, even in inaccessible areas of the vehicle. Owing to the small amount of installation space available, these adjustment drives should be as small as possible. 
     In order to satisfy the requirements of customers in the vehicle industry, especially in the automotive industry, the components of vehicles are adapted to specific models and, in some cases, also to specific customer requirements within the same model range. At the same time, it is important to minimize the number of components within vehicle production to make stock holding as inexpensive as possible and ensure that component numbers are not too large. This makes the components economical to produce. 
     To adjust components, e.g. a tailgate, a sliding roof or, in particular, to adjust the height or tilt of a seat, there is often a need for adjustment drives which have a large reduction and transmit a high torque. In general, planetary gears are used for this purpose, and often a plurality of gear stages are arranged in series. However, the disadvantage with this arrangement is the not inconsiderable rolling contact noise. 
     For any sensors which may be required, in particular a position detection system, the conventional practice is to provide a volume in adjustment drives into which the sensor system can be integrated when required, in particular as a plug-in board. As a result, the volume of the adjustment drive when the sensor system is not required is unnecessarily large. On the other hand, the installation space available in the vehicle is very limited. 
     SUMMARY OF THE INVENTION 
     It is the object of the invention to provide an adjustment drive for driving a component which transmits a high torque, is of very compact construction, can be used in inaccessible areas, can be used in many different ways, in particular for different vehicle models or for different requirements on the same vehicle or vehicle model and, in particular, for positioning tasks, which is quiet, can be produced at low cost and can be assembled easily. 
     The object is achieved with an adjustment drive, in particular for a vehicle, which is provided for driving a component, having an input unit, which comprises a first output shaft, to which an output unit or an intermediate unit, which is arranged between the input unit and the output unit, can be adapted in a modular manner. 
     The adjustment drive according to the invention can therefore be employed in three embodiments, either without an output and intermediate unit, or with an adapted output unit, or with an adapted output and intermediate unit. The adjustment drive can therefore be used for various adjustment tasks, depending on requirements, in particular in the same vehicle or the same vehicle model range or in different vehicles. 
     Moreover, the intermediate unit can be adapted in a modular manner between the input unit and the output unit. This enables the input unit, the intermediate unit and the output unit to be manufactured in a modular manner. As a result, the respective numbers of these units can be adapted to requirements. This keeps the cost of stock holding to a reasonable level. 
     The intermediate unit preferably has at least one additional function, in particular a sensor, a slipping clutch, an overload safeguard, a speed-increasing stage etc. In another preferred option, the intermediate unit has a plurality of additional functions. Adapting the intermediate unit to the input unit and between the input and the output unit makes it possible to integrate a large number of different tasks and functions into the adjustment drive. At the same time, the installation space required by the adjustment drive is always optimum since it increases in size only in the case where the output unit or the intermediate unit and the output unit is/are adapted, by the volume required by said units. 
     In a particularly preferred embodiment, the intermediate unit has at least one sensor for position detection. Conventional sensors, e.g. incremental encoders, absolute encoders, resolvers etc. can be used as sensors for position detection. The arrangement of the intermediate unit ahead of the output unit is particularly advantageous here since the transmission ratio of the output unit can be selected in such a way that it can offer sufficient resolution with respect to the positioning signals. Moreover, the quality of the signals is impaired only by the backlash of the output unit, and the backlash of the input unit has no effect on position detection. 
     In a preferred embodiment, the input unit comprises a first worm gear and a second worm gear. In this case, the first worm gear and the second worm gear are preferably arranged in series as a double worm gear. The combination of two worm gears allows a very large speed reduction in a very small installation space. 
     An input shaft, which drives the input unit, the first output shaft of the input unit and a second output shaft of the output unit are preferably arranged coaxially. In this case, the second output shaft is preferably provided to drive the component. 
     In order to achieve this, the input unit preferably comprises a spur gear. The spur gear likewise preferably comprises the first output shaft. Moreover, the spur gear preferably comprises a spur wheel, which is arranged on the first output shaft. Moreover, the spur gear preferably comprises a gearwheel which is arranged on an intermediate shaft, in particular an intermediate shaft arranged parallel to the axis of the first input shaft, and which is in engagement with the spur wheel. 
     In another preferred embodiment, the output unit comprises a planetary gear. Depending on requirements, however, some other gear can also be used for the output unit, especially if a smaller reduction is required. The planetary gear preferably has a sun wheel, which can be adapted to the first output shaft. This arrangement allows a large reduction and the coaxial arrangement of the first output shaft and of the second output shaft. 
     As another preferred option, the intermediate unit can be adapted to the first output shaft, wherein the sun wheel of the planetary gear of the output unit can be adapted to the intermediate unit. This makes it possible to arrange the intermediate unit between the input unit and the output unit. 
     The input unit is preferably drivable by means of a drive. An electric motor is preferably used as a drive. However, it is also possible to use some other drive provided for performing mechanical work. 
     The input unit is preferably arranged in a first housing part, with the intermediate unit being arranged in a second housing part and the output unit being arranged in a third housing part. The parts of the gear associated with each unit are mounted in the housing parts and are protected against the ingress of dirt and moisture by the housing parts. 
     The output is preferably mounted on the first housing part. 
     The adjustment drive according to the invention is very versatile since it can be adapted in a very flexible manner to the requirements demanded since it is always of optimally compact construction and since sensors and/or other additional functions can optionally be integrated into it. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The invention is described below with reference to figures. The figures are purely illustrative and do not restrict the general inventive concept. 
         FIG. 1  shows an adjustment drive according to the invention schematically. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an adjustment drive  6  according to the invention schematically. The adjustment drive  6  comprises an input unit  2 , which has an input shaft  12  that can be driven by means of an electric motor  1 . 
     Arranged on the input shaft  12  is a first worm  2 . 11  of a first worm gear  2 . 1 , which interacts with a first worm gear wheel  2 . 12  of the first worm gear  2 . 1 . The first worm gear wheel  2 . 12  is arranged on a worm shaft  22 , which is arranged substantially transversely to the input shaft  12 . 
     Arranged on the worm shaft  22  is a second worm  2 . 21  of a second worm gear  2 . 2 , which interacts with a second worm gear wheel  2 . 22  of the second worm gear  2 . 2 , which is arranged on an intermediate shaft  23 . The intermediate shaft  23  is arranged substantially transversely to the worm shaft  22  and hence substantially parallel to the axis of the input shaft  12 . 
     The first worm gear  2 . 1  and the second worm gear  2 . 2  are therefore arranged in series to give a double worm gear. 
     When the input shaft  12  is driven, the worm shaft  22  is driven via the first worm gear  2 . 1  and, for its part, drives the intermediate shaft  23  via the second worm gear  2 . 2 . 
     Arranged on the intermediate shaft  23  is a gearwheel  2 . 32 , which interacts with a spur wheel  2 . 31  and, together with the latter, forms a spur gear  2 . 3 . The spur wheel  2 . 31  is arranged on a first output shaft  24  of the input unit  2 . This arrangement makes it possible to arrange the first output shaft  24  substantially coaxially with the input shaft  12 . When the intermediate shaft  23  is driven, gearwheel  2 . 32  is driven, said gearwheel being at least partially in engagement with the spur wheel  2 . 31  of the spur gear  2 . 3 , and, as a result, the spur wheel  2 . 31  is driven. As a result, the first output shaft  24  is driven. 
     In the embodiment of the adjustment drive  6  illustrated here, an intermediate unit  3  is adapted to the first output shaft  24 . The intermediate unit  3  comprises a sensor  3 . 1  and another additional function  3 . 2 . 
     A person skilled in the art will understand that the intermediate unit  3  has a connecting shaft  33 , which can be adapted at the end facing the input unit  2  to the first output shaft  24  of the input unit  2 , and the output unit  4  can be adapted at the end thereof which is remote from the input unit  2 . Here, the connecting shaft  33  is indicated by hatching. In the adapted state, it can be driven by the first output shaft  24  of the input unit  2 . A person skilled in the art will understand that, on the one hand, it can be of integral design, depending on the requirements of the intermediate unit  3 . However, it can also comprise additional functions  3 . 2 , such as a slipping clutch or a gear, which require manufacture in several parts. In this case, the components of the connecting shaft  33  are arranged substantially coaxially. 
     The adaptation of the intermediate unit  3  and of the output unit  4  increases the volume of the adjustment drive  6  by the volume of the intermediate unit  3  and the volume of the output unit  4 . In cross section, the dimensions of the output unit  4  and the dimensions of the intermediate unit  3  preferably do not exceed the dimensions of the input unit  2 , and therefore it is, in particular, the length of the adjustment drive  6  which is increased, by the length y of the output unit  4  plus the length x of the intermediate unit  3 . 
     The output unit  4  of the adjustment drive  6  has a planetary gear  4 . 1 . The planetary gear  4 . 1  comprises a sun wheel  4 . 11 , which can be adapted to the intermediate shaft  33  of the intermediate unit  3  and, in the adapted state, can be driven by the latter. The planetary gear  4 . 1  comprises planet wheels  4 . 12 , which are connected to one another by means of a planet carrier  4 . 13 . A second output shaft  45  is arranged on the planet carrier  4 . 13 . The second output shaft  45  is arranged coaxially with the sun wheel  4 . 11  and with the first output shaft  24 . 
     When the sun wheel  4 . 11  is driven, the planet wheels  4 . 12  are driven and, as a result, the planet carrier  4 . 13  rotates. As a result, the second output shaft  45 , which is arranged on the planet carrier  4 . 13 , rotates. 
     The sun wheel  4 . 11  of the planetary gear  4 . 1  of the output unit  4  can also be adapted directly to the first output shaft  24  if the functions integrated into the intermediate unit  3  are not required. The volume of the adjustment drive  6  is then enlarged only by the volume of the output unit  4 . Since, in cross section, the dimensions of the output unit  4  preferably do not exceed the dimensions of the input unit  2 , the length of the adjustment drive  6  is in this case increased only by the length y of the output unit  4 . 
     In addition, the adjustment drive  6  can also be used to drive a component  5  without the intermediate unit  3  and the output unit  4  if the requirements provided by the intermediate unit  3  and the output unit  4  are not demanded. Thus, both the first output shaft  24  and the second output shaft  45  can be used to drive the component  5 . 
     A tailgate is preferably provided as component  5 . However, the adjustment drive  6  is also suitable for adjusting seats, sliding roofs or similar adjustable units. 
     The input unit  2  has a first housing part  21 , the intermediate unit  3  has a second housing part  31  and the output unit  4  has a third housing part  41 , in which their respective gear components  2 . 1 - 2 . 3 ,  3 . 1 ,  4 . 1  are mounted. The electric motor  1  is furthermore mounted on the first housing part  21 . The housing parts  21 ,  31 ,  41  are joined together, preferably directly, during adaptation, thus protecting the gear components  2 . 1 - 2 . 3 ,  3 . 1 ,  4 . 1  from dirt and liquids.