Internal park brake system, apparatus, and method

Abstract

A park brake system for an electric motor actuator is provided. The system may comprise a micro-motor, and one or more gears. The system may be configured to exert a radial force on a shaft of the electric motor actuator to lock the actuator. Moreover, in various embodiments, the system may be bi-stable.

What is claimed is: 
     
         1 . A park brake, comprising:
 a micro-motor comprising a gear train;   a first gear coupled to the micro-motor;   a second gear coupled to a shaft, the first gear configured to operatively engage the second gear, wherein the shaft binds in response to the micro-motor being energized.   
     
     
         2 . The park brake of  claim 1 , wherein the first gear is a pinion gear and the second gear is a sector gear. 
     
     
         3 . The park brake of  claim 1 , wherein the second gear is a sector gear comprising a non-uniform radius. 
     
     
         4 . The park brake of  claim 1 , wherein the shaft is a portion of an electric motor actuator. 
     
     
         5 . The park brake of  claim 4 , wherein the shaft is installed in an eccentric bushing. 
     
     
         6 . The park brake of  claim 5 , wherein the shaft binds in the eccentric bushing in response to the micro-motor being energized. 
     
     
         7 . The park brake of  claim 1  further comprising a wrap spring installable over the shaft and coupled to the second gear. 
     
     
         8 . The park brake of  claim 7 , wherein the shaft is constrained by the wrap spring in response to the micro-motor being energized. 
     
     
         9 . The park brake of  claim 1 , wherein the micro-motor is automatically energized in response to a pre-determined condition. 
     
     
         10 . An electric motor actuator, comprising:
 an electric motor;   a shaft coupled to the electric motor   a sector gear coupled to the shaft;   a micro-motor;   a pinion gear coupled to the micro-motor, the pinion gear configured to operatively engage the sector gear.   
     
     
         11 . The electric motor actuator of  claim 10 , wherein the sector gear comprises a non-uniform profile. 
     
     
         12 . The electric motor actuator of  claim 11 , wherein the sector gear is configured to exert a force on the shaft in response to the micro-motor being energized. 
     
     
         13 . The electric motor actuator of  claim 10 , further comprising a wrap spring installable on the shaft. 
     
     
         14 . The electric motor actuator of  claim 13 , wherein the shaft is engaged by the wrap spring in response to the micro-motor being energized. 
     
     
         15 . The electric motor actuator of  claim 10 , wherein the micro-motor comprises a gear train. 
     
     
         16 . The electric motor actuator of  claim 15 , wherein the gear train operatively couples to the pinion gear. 
     
     
         17 . An electric motor actuator, comprising:
 a shaft;   a shaft support, the shaft being installed within the shaft support;   a second gear installed on the shaft;   a first gear configured to operatively engage the second gear;   a motor configured to drive the first gear, wherein in response to the motor being energized, the first gear drives the second gear causing the shaft to bind with the shaft support.   
     
     
         18 . The electric motor actuator of  claim 17 , wherein the first gear is a pinion gear and the second gear is a sector gear. 
     
     
         19 . The electric motor actuator of  claim 17 , wherein the second gear is a sector gear that is a cam and is configured to exert a radial force on the shaft. 
     
     
         20 . The electric motor actuator of  claim 17 , wherein the motor comprises a gear train and the gear train is operatively coupled to the first gear, and wherein a gear ratio associated with the gear train and the first gear is approximately 90:1 to 450:1.