Steer-by-wire handwheel actuator

Abstract

A steer-by-wire handwheel actuator in a vehicle is presented. The handwheel actuator comprises a driver input shaft; a gear train connected to the driver input shaft; a motor responsive to control signals from a controller and variably geared to the gear train; a electro-mechanical brake responsive to the control signals from the controller and geared to one of the driver input shaft and the gear train; and a stop mechanism attached to a housing and coupled to one of the electro-mechanical brake and the gear train.

1 . A steer-by-wire handwheel actuator utilizing a controller operative to accept as input thereto data from the steer-by-wire system and generate therefrom control signals in a vehicle comprising: 
 a driver input shaft;    a gear train connected to the driver input shaft;    a motor responsive to the control signals from the controller and variably geared to the gear train, the motor including a motor shaft driven therefrom and a motor pulley connected to the motor shaft and having cogs circumferentially arranged;    an electro-mechanical brake responsive to the control signals from the controller and geared to one of the driver input shaft and the gear train; and    a stop mechanism attached to a housing and coupled to one of the electro-mechanical brake and the gear train,    wherein the gear train is a pulley and gear train assembly, said gear train assembly including:    a driver feedback pulley connected to the driver input shaft;    a speed reducer pulley having cogs circumferentially arranged for positive engagement with the motor pulley cogs and being connected to the driver input shaft; and    a spur gear connected to the driver input shaft.    
   
   
       2 - 3 . (canceled)  
   
   
       4 . The steer-by-wire handwheel actuated as set forth in  claim 1  wherein the speed reducer pulley and the motor pulley are positively engages via a cogged belt.  
   
   
       5 . The steer-by-wire handwheel actuator as set forth in  claim 1  further comprising: 
 a modular unit having a biasing member to provide mechanical resistance to one of the driver input shaft and the gear train.    
   
   
       6 . The steer-by-wire handwheel actuator as set forth in  claim 5  wherein the modular unit includes a ball nut assembly operably connected to said driver input shaft.  
   
   
       7 . The steer-by-wire handwheel actuator as set forth in  claim 6  wherein said ball nut assembly is biased in a predetermined position corresponding to an on center steering position.