Two-stage gear mechanism

Abstract

A two-stage gear mechanism includes a drive shaft having a first gear stage disposed in a fixed housing and containing planetary wheels. The two-stage gear mechanism also includes a second gear stage, driven by the first gear stage and meshing with a drive shaft. Each of the planetary wheels is formed as a stepped double gear wheel with a first gear wheel that engages the drive shaft, and with a second gear wheel that points toward the direction of the output side. The bearing axles of each of the planetary wheels are disposed spatially fixed within the housing. The second gear wheels of the planetary wheels mesh with a hollow wheel of the second gear stage, the hollow wheel being non-rotationally coupled to the drive shaft.

What is claimed is:  
     
         1 . A two-stage gear mechanism, comprising: 
 a drive shaft;    a first gear stage that includes a plurality of planetary wheels each configured and arranged as a stepped double gear wheel having a first gear wheel that engages said drive shaft, and a second gear wheel; and    a second gear stage driven by said first gear stage and meshing with an output shaft, wherein said second gear stage includes a hollow wheel that is non-rotationally coupled to said output shaft.    
     
     
         2 . The gear mechanism of  claim 1 , wherein said planetary wheels are driven simultaneously by said drive shaft.  
     
     
         3 . The gear mechanism of  claim 2 , wherein said planetary wheels are configured and arranged symmetrically about said drive shaft.  
     
     
         4 . The gear mechanism of  claim 3 , comprising: 
 a housing; and    a casing fixedly situated within said housing, wherein said casing has a plurality of openings to accept spatially fixed bearing axles of said planetary wheels.    
     
     
         5 . The gear mechanism of  claim 4 , wherein said housing includes a first housing part and a second housing part, and a set of ends of the spatially fixed bearing axles are seated in the openings of said casing, and the other set of ends of said spatially fixed bearing axles are seated in openings of said second housing part.  
     
     
         6 . The gear mechanism of  claim 5 , wherein said second housing part includes a motor flange for coupling said gear mechanism to a motor.  
     
     
         7 . The gear mechanism of  claim 6 , wherein said first housing part is pot-shaped and rigidly seated on the second housing part, and said first housing part has a central bore in which is situated a first bearing bush.  
     
     
         8 . The gear mechanism of  claim 7 , wherein said casing supports a second bearing bush centrically to the gear axis.  
     
     
         9 . The gear mechanism of  claim 8 , wherein said first and second bearing bushes support said output shaft axially and radially.  
     
     
         10 . The gear mechanism of  claim 9 , wherein said hollow wheel is pot-shaped and has teeth at its interior circumferential surface, which mesh with said second gear wheels of said planetary wheels, and which are seated non-rotationally on said drive shaft.  
     
     
         11 . The gear mechanism of  claim 10 , wherein the motor is non-rotationally connected to said housing of said gear mechanism.  
     
     
         12 . A two-stage gear mechanism, comprising: 
 a drive shaft;    a first gear stage that includes a plurality a planetary wheels arranged radially around said drive shaft and coupled to said drive shaft, wherein each of said planetary wheels is configured and arranged as a stepped double gear wheel having a first gear wheel that engages said drive shaft, and a second gear wheel that is coaxial with said first gear wheel; and    a second gear stage including a hollow wheel that meshes with said second gear wheels of said planetary wheels, said hollow wheel being to an output shaft.