Hydraulically retractable hydraulic motor

Abstract

A method and apparatus for hydraulically engaging and disengaging a hydraulic motor comprising a rotor and a stator.

What is claimed is:  
     
         1 . A retractable shaft motor assembly comprising: 
 an axially moveable drive shaft;    an actuator rod in communication with the drive shaft;    a hydraulic actuator in communication with the actuator; and    a motor positioned between the drive shaft and the hydraulic actuator.    
     
     
         2 . The apparatus of  claim 1  in which the actuator rod is slideably positioned along an axis of the motor.  
     
     
         3 . The apparatus of  claim 1  in which the actuator rod is non-torque-bearing.  
     
     
         4 . The apparatus of  claim 1  in which the motor is a hydraulic motor.  
     
     
         5 . A hydraulically retractable shaft motor comprising: 
 a motor, the motor having a longitudinal axis;    an axially moveable output shaft, the output shaft having an interface for selectively engaging an external rotary load; and    an axial hydraulic actuator assembly connected to the output shaft.    
     
     
         6 . The apparatus of  claim 5  in which the hydraulic actuator assembly comprises a cylinder, a piston, and an actuator rod.  
     
     
         7 . The apparatus of  claim 5  in which the motor is a hydraulic motor comprising a rotor and a stator; and the hydraulic actuator assembly comprises a non-torque bearing actuator rod.  
     
     
         8 . The apparatus of  claim 6  in which the actuator rod is non-torque bearing.  
     
     
         9 . The apparatus of  claim 8  in which the actuator rod is rotatably connected to the piston.  
     
     
         10 . The apparatus of  claim 8  in which the motor and the output shaft have longitudinal coacting splines.  
     
     
         11 . A method of disengaging a hydraulic motor having a rotor, a stator, and a longitudinally moveable output shaft in selective communication with the rotor, comprising: 
 hydraulically and longitudinally moving the output shaft relative to the rotor whereby the output shaft disengages from the rotor.