Gear unit and motor-driven gear unit for cable window lift systems

Abstract

Gear unit and a motor-driven gear unit for cable window lift systems of motor vehicles, including drive and gear mechanism which cooperates with the drive and is coupled to rotatably mounted cable drum for winding and unwinding cable of the cable window lift system. According to the invention a diameter of the cable drum of the gear unit or motor-driven gear unit is in a range from about 22 mm to about 30 mm, wherein a gear ratio of the gear mechanism ranges from about 1:38 to about 1:55. A cable drum has, on its end side, claws which engage in correspondingly designed recesses on the end side of a worm wheel. Electric motors having a maximum driving torque of only about 5.7 Nm can be used. Overall, the size of the gear unit or motor-driven gear unit can be reduced by about 40-50%.

1 . A gear unit for cable window lift systems of motor vehicles, comprising a drive and a gear mechanism which cooperates with the drive and is coupled to a rotatably mounted cable drum for winding and unwinding a cable of the cable window lift system, wherein a diameter of the cable drum is in a range from about 22 mm to about 30 mm and more preferably in a range from about 24 mm to about 28 mm and wherein a gear ratio of the gear mechanism is in a range from about 1:38 to about 1:55 and more preferably in a range from about 1:42 to about 1:51.  
     
     
         2 . A gear unit as claimed in  claim 1 , in which the cable drum is designed such that the gear unit can be used optionally for one of an electric and a manual drive.  
     
     
         3 . A gear unit as claimed in  claim 1 , in which the cable drum is designed optionally for one of a cable-operated window lift system for a front motor vehicle door and a cable-operated window lift system for a rear motor vehicle door.  
     
     
         4 . A gear unit as claimed in  claim 1 , in which the cable drum is coupled directly and without the use of additional damping elements to the gear mechanism.  
     
     
         5 . A gear unit as claimed in  claim 4 , in which the cable drum has on an end side at least two engagement elements which engage in a form-fitting manner in at least two counterelements on an end side of the worm wheel, said counterelements being designed to correspond to the engagement elements.  
     
     
         6 . A gear unit as claimed in  claim 5 , in which the engagement elements are arranged on diametrically opposite sides of the cable drum.  
     
     
         7 . A gear unit as claimed in  claim 5 , in which the engagement elements are designed as protrusions on the end side of the cable drum and the counterelements are designed as recesses on the end side of the worm wheel, said recesses being designed to correspond to the protrusions.  
     
     
         8 . A gear unit as claimed in  claim 4 , in which a worm wheel of the gear mechanism is accommodated in a housing section such that a sealing means seals off the worm wheel with respect to the housing section.  
     
     
         9 . A gear unit as claimed in  claim 8 , in which the sealing means surrounds an upper edge of the worm wheel.  
     
     
         10 . A gear unit as claimed in  claim 8 , in which the sealing means surrounds an upper edge of the housing section.  
     
     
         11 . A gear unit as claimed in  claim 6 , which is designed optionally for one of a manual and an electric drive.  
     
     
         12 . A gear unit as claimed in  claim 11 , in which an engagement element has a shoulder for receiving a brake spring or wrap spring of a manual cable window lift system.  
     
     
         13 . A gear unit as claimed in  claim 11 , in which provided on a housing are fixing regions for fixing the gear unit, wherein the fixing regions are identical for a manual and for a motor-driven gear unit.  
     
     
         14 . A motor-driven gear unit for cable window lift systems of motor vehicles, comprising an electric motor which is coupled to the gear unit, wherein a driving torque of the electric motor is at most about 5.7 Nm and/or an output power of the electric motor is at most about 10 W.  
     
     
         15 . A motor-driven gear unit as claimed in  claim 14 , in which the electric motor is designed both for a cable window lift system for a front motor vehicle door and for a cable window lift system for a rear motor vehicle door.