Vehicle steering device

Abstract

Disclosed herein is a vehicle steering device, comprising, a pancake harmonic drive with an external wave generator surrounding a flex spline that is in mesh with both a tooth matched spline and a dynamic spline, a rotatable input shaft in operable communication with the harmonic drive, a rotatable output shaft in operable communication with the harmonic drive, and a motor in operable communication with the wave generator, and the gear ratio of the input shaft to the output shaft is altered by rotation of the motor.

1 . A vehicle steering device, comprising: 
 a pancake harmonic drive with an external wave generator surrounding a flex spline that is in mesh with both a tooth matched spline and a dynamic spline;    a rotatable input shaft in operable communication with the harmonic drive;    a rotatable output shaft in operable communication with the harmonic drive; and    a motor in operable communication with the wave generator, and the gear ratio of the input shaft to the output shaft is altered by rotation of the motor.    
   
   
       2 . The vehicle steering device of  claim 1 , further comprising: 
 a locking mechanism for preventing rotation of the wave generator.    
   
   
       3 . The vehicle steering device of  claim 2 , wherein the locking mechanism engages the wave generator.  
   
   
       4 . The vehicle steering device of  claim 1 , wherein the input shaft is in operable communication with the tooth matched spline and the output shaft is in operable communication with the dynamic spline.  
   
   
       5 . The vehicle steering device of  claim 4 , wherein the tooth matched spline and the dynamic spline are engaged with the flex spline.  
   
   
       6 . The vehicle steering device of  claim 5 , wherein the flex spline is positioned within the external wave generator.  
   
   
       7 . The vehicle steering device of  claim 1 , wherein the wave generator is rotationally fixed to the motor.  
   
   
       8 . The vehicle steering device of  claim 7 , wherein the motor is coaxial with the wave generator.  
   
   
       9 . The vehicle steering device of  claim 7 , wherein the motor is parallel to the input shaft but is not coaxial with the input shaft.  
   
   
       10 . The vehicle steering device of  claim 1 , wherein the wave generator is a rotor of the motor.  
   
   
       11 . The vehicle steering device of  claim 1 , further comprising: 
 a sensor, receptive to torque and in operable communication with an engine control unit (ECU), the ECU being in operable communication with the motor.    
   
   
       12 . The vehicle steering device of  claim 1 , wherein the steering device includes electric power assist.  
   
   
       13 . The vehicle steering device of  claim 1 , wherein the steering device includes hydraulic power assist.