System and method for dynamically affecting a force applied through a rail vehicle axle

Abstract

A system is provided for dynamically affecting a force applied through at least one axle of a rail vehicle configured to travel along a rail track. The rail vehicle includes a plurality of axles and a plurality of wheels received by the plurality of axles. The system includes a device configured to selectively impart the force through the at least one axle to control a respective weight of the at least one axle on the rail track for affecting a traction performance of the rail vehicle traveling along the rail track.

1 . A system for dynamically affecting a force applied through at least one axle of a rail vehicle configured to travel along a rail track, said rail vehicle having a plurality of axles and a plurality of wheels being received by said plurality of axles, said system comprising:
 a device configured to selectively impart said force through said at least one axle to control a respective weight of said at least one axle on said rail track for affecting a traction performance of said rail vehicle traveling along said rail track.   
   
   
       2 . The system of  claim 1 , wherein said force is a normal force applied through said at least one axle in a normal direction to said rail track, said rail vehicle is a locomotive, said device is at least one hydraulic actuator coupled to a respective locomotive axle. 
   
   
       3 . The system of  claim 2 , further comprising:
 a variable displacement pump coupled to said hydraulic actuator, said variable displacement pump configured to supply a pressurized hydraulic fluid at a selectively controlled pressure to said hydraulic actuator, said hydraulic actuator configured to selectively impart said force through said respective axle based upon said selectively controlled pressure.   
   
   
       4 . The system of  claim 3 , wherein said hydraulic actuator is directly coupled to said respective locomotive axle. 
   
   
       5 . The system of  claim 4 , further comprising:
 at least one control valve coupled to said variable displacement pump and said hydraulic actuator, said at least one control valve being selectively activated to control said force imparted through said respective axle.   
   
   
       6 . The system of  claim 3 , further comprising:
 a compliant member disposed between said hydraulic actuator and said respective axle such that said hydraulic actuator is coupled to said respective axle in a compliant manner.   
   
   
       7 . The system of  claim 6 , further comprising:
 a pair of displacement limits coupled to said hydraulic actuator to limit said force selectively imparted on said respective axle.   
   
   
       8 . The system of  claim 6 , further comprising:
 at least one control valve coupled to said variable displacement pump and said hydraulic actuator, said at least one control valve being selectively activated to control a position of said hydraulic actuator.   
   
   
       9 . The system of  claim 2 , further comprising:
 a positive displacement pump coupled to said hydraulic actuator, said positive displacement pump configured to selectively control a position of said hydraulic actuator based upon supplying a pressurized hydraulic fluid at a variable pressure to said hydraulic actuator, said hydraulic actuator configured to selectively impart said force through said respective axle based upon said selectively controlled position of said hydraulic actuator.   
   
   
       10 . The system of  claim 9 , further comprising:
 a compliant member disposed between said hydraulic actuator and said respective axle such that said hydraulic actuator is coupled to said respective axle in a compliant manner.   
   
   
       11 . The system of  claim 9 , further comprising:
 at least one control valve coupled to said positive displacement pump and said hydraulic actuator, said at least one control valve being selectively activated to control said position of said hydraulic actuator.   
   
   
       12 . The system of  claim 9 , further comprising:
 a pair of displacement limits coupled to said hydraulic actuator to limit said force selectively imparted on said respective axle.   
   
   
       13 . The system of  claim 2 , wherein said at least one hydraulic actuator is configured to selectively impart said force through said respective at least one axle based upon energy captured from a vibration of a vibrated axle of said plurality of axles along said rail track. 
   
   
       14 . The system of  claim 13 , further comprising:
 a pressurized hydraulic fluid pump coupled to said vibrated axle and said hydraulic actuator, said captured vibrational energy is utilized to pressurize said hydraulic fluid within said pump.   
   
   
       15 . The system of  claim 14 , wherein said hydraulic actuator is configured to selectively impart said force through said respective axle based upon said pressurized hydraulic fluid delivered from said pump to said hydraulic actuator. 
   
   
       16 . The system of  claim 15 , further comprising:
 a pair of displacement limits coupled to said hydraulic actuator to limit said force selectively imparted on said respective axle.   
   
   
       17 . The system of  claim 14 , further comprising:
 a compliant member disposed between said hydraulic actuator and said respective axle such that said hydraulic actuator is coupled to said respective axle in a compliant manner.   
   
   
       18 . The system of  claim 17 , wherein upon said hydraulic actuator having selectively imparted said force through said respective axle, said compliant member is configured to exert a reactive force on said respective axle. 
   
   
       19 . The system of  claim 14 , wherein said plurality of locomotive axles include at least one powered axle and at least one nonpowered axle, said hydraulic actuator coupled a respective nonpowered axle is configured to selectively impart an upward force in a normal direction to said rail track. 
   
   
       20 . The system of  claim 14 , further comprising:
 at least one control valve coupled to said hydraulic actuator to selectively control a pressure difference across said hydraulic actuator, said at least one control valve configured to be activated to rapidly remove a weight shift imparted on a respective axle based upon said selective imparting of said force on said respective axle.   
   
   
       21 . The system of  claim 2 , wherein said device is at least one pneumatic actuator coupled to a respective locomotive axle. 
   
   
       22 . The system of  claim 21 , further comprising:
 a controlled pressure regulator coupled to said pneumatic actuator, said controlled pressure regulator configured to selectively control the force imparted by said pneumatic actuator based upon supplying pressurized air at a constant pressure to said pneumatic actuator, said pneumatic actuator configured to selectively impart said force through said respective axle.   
   
   
       23 . The system of  claim 22 , further comprising:
 at least one control valve coupled to said controlled pressure regulator and said pneumatic actuator, said at least one control valve being selectively activated to control said position of said pneumatic actuator.   
   
   
       24 . The system of  claim 22 , further comprising:
 a pair of displacement limits coupled to one of a locomotive axle and said pneumatic actuator, said respective axle configured to be received by a respective locomotive truck frame, said pair of displacement limits being configured to limit said position of said respective axle based upon said controlled position of said pneumatic actuator.   
   
   
       25 . A method for dynamically affecting a force applied through at least one axle of a rail vehicle configured to travel along a rail track, said rail vehicle having a plurality of axles and a plurality of wheels being received by said plurality of axles, said method comprising:
 configuring a device to selectively impart said force through said at least one axle to control a respective weight of said at least one axle on said rail track for affecting a traction performance of said rail vehicle traveling along said rail track.