Transfer Case Lubrication System with Disengagable Pump

Abstract

A lubrication system ( 300 ) for a transfer case ( 200 ) includes a shaft ( 302 ) having a lubricant inlet port ( 306 ) and a hollow bore ( 304 ) for transporting lubricant within the shaft ( 302 ), a pump ( 310 ) having a pump housing ( 312 ) and one or more pumping elements ( 318 ) that are disposed in the pump housing ( 312 ), and a clutch assembly ( 330 ). The clutch assembly 330 has an engaged position, in which rotational force from the shaft ( 302 ) is transferred to the one or more pumping elements ( 318 ) to cause operation of the pump ( 310 ), and a disengaged position, in which rotational force from the shaft ( 302 ) is not transferred to the one or more pumping elements ( 318 ). An actuator ( 370, 410 ) is operable to cause the clutch assembly ( 330 ) to move between the engaged position and the disengaged position in response to signals received from a controller ( 233 ).

What is claimed is: 
     
         1 . A lubrication system ( 300 ) for a transfer case ( 120 ,  200 ), comprising:
 a shaft ( 302 ) having a lubricant inlet port ( 306 ) and a hollow bore ( 304 ) for transporting lubricant within the shaft ( 302 );   a pump ( 310 ) having a pump housing ( 312 ) and one or more pumping elements ( 318 ) that are disposed in the pump housing ( 312 );   a clutch assembly ( 330 ) having an engaged position, in which rotational force from the shaft ( 302 ) is transferred to the one or more pumping elements ( 318 ) to cause operation of the pump ( 310 ), and a disengaged position, in which rotational force from the shaft ( 302 ) is not transferred to the one or more pumping elements ( 318 ); and   an actuator ( 370 ,  410 ) that is operable to cause the clutch assembly ( 330 ) to move between the engaged position and the disengaged position in response to signals received from a controller ( 233 ).   
     
     
         2 . The lubrication system ( 300 ) of  claim 1 , wherein the actuator ( 410 ) is one of an electrical actuator, a hydraulic actuator, or a pneumatic actuator. 
     
     
         3 . The lubrication system ( 300 ) of  claim 1 , wherein the clutch assembly ( 330 ) includes a first clutch rotor ( 340 ) that rotates independent of the shaft ( 302 ) when the clutch assembly ( 330 ) is in the disengaged position and a second clutch rotor ( 350 ) that rotates in response to rotation of the shaft ( 302 ). 
     
     
         4 . The lubrication system ( 300 ) of  claim 3 , wherein the actuator ( 410 ) has a moveable member ( 412 ) that engages the second clutch rotor ( 350 ) of the clutch assembly ( 330 ). 
     
     
         5 . The lubrication system ( 300 ) of  claim 4 , wherein the moveable member ( 412 ) of the actuator ( 410 ) is seated in an annular groove ( 42 ) formed on an outer periphery of the second clutch rotor ( 350 ) of the clutch assembly ( 330 ). 
     
     
         6 . The lubrication system ( 300 ) of  claim 4 , wherein the moveable member ( 412 ) of the actuator ( 410 ) is a shift fork. 
     
     
         7 . The lubrication system ( 300 ) of  claim 1 , wherein the actuator ( 370 ,  410 ) is operable to move the clutch assembly ( 330 ) in a first direction. 
     
     
         8 . The lubrication system ( 300 ) of  claim 7 , further comprising:
 a biasing element ( 360 ) that is operable to move the clutch assembly ( 330 ) in a second direction, wherein the second direction is opposite the first direction.   
     
     
         9 . The lubrication system ( 300 ) of  claim 1 , wherein the actuator ( 370 ,  410 ) is operable to move the clutch assembly ( 330 ) in a first direction and a second direction. 
     
     
         10 . The lubrication system ( 300 ) of  claim 1 , wherein the actuator is an electromagnetic coil ( 370 ) that is operable to produce a magnetic field when energized, and energization of the electromagnetic coil ( 370 ) causes the clutch assembly ( 330 ) to move from the engaged position toward the disengaged position. 
     
     
         11 . The lubrication system ( 300 ) of  claim 1 , wherein the actuator is an electromagnetic coil ( 370 ) that is operable to produce a magnetic field when energized, and energization of the electromagnetic coil ( 370 ) causes the clutch assembly ( 330 ) to move from the disengaged position toward the engaged position. 
     
     
         12 . A lubrication system ( 300 ) for a transfer case ( 120 ,  200 ), comprising:
 a shaft ( 302 ) having a lubricant inlet port ( 306 ) and a hollow bore ( 304 ) for transporting lubricant within the shaft ( 302 );   a pump ( 310 ) having a pump housing ( 312 ) and one or more pumping elements ( 318 ) that are disposed in the pump housing ( 312 );   a first clutch rotor ( 340 ) that is disposed on the shaft ( 302 ) and is connected to the one or more pumping elements ( 318 ) such that rotation of the first clutch rotor ( 340 ) causes operation of the one or more pumping elements ( 318 ) of the pump ( 310 );   a second clutch rotor ( 350 ) that rotates in response to rotation of the shaft ( 302 ) and has an engaged position, in which rotational force from the shaft ( 302 ) is transferred to the first clutch rotor ( 340 ) to cause operation of the pump ( 310 ), and a disengaged position, in which rotational force from the shaft ( 302 ) is not transferred to the first clutch rotor ( 340 ); and   an actuator ( 370 ,  410 ) connected to the second clutch rotor ( 350 ) that is operable to cause the second clutch rotor ( 350 ) to move between the engaged position and the disengaged position.   
     
     
         13 . The lubrication system ( 300 ) of  claim 12 , wherein the first clutch rotor ( 340 ) rotates independent of the shaft ( 302 ) when the second clutch rotor ( 350 ) is in the disengaged position. 
     
     
         14 . The lubrication system ( 300 ) of  claim 12 , wherein the actuator ( 410 ) is one of an electrical actuator, a hydraulic actuator, or a pneumatic actuator. 
     
     
         15 . The lubrication system ( 300 ) of  claim 12 , wherein the actuator is an electromagnetic coil ( 370 ) that is operable to produce a magnetic field when energized, and energization of the electromagnetic coil ( 370 ) causes the second clutch rotor ( 350 ) to move from the engaged position toward the disengaged position. 
     
     
         16 . The lubrication system ( 300 ) of  claim 12 , wherein the actuator is an electromagnetic coil ( 370 ) that is operable to produce a magnetic field when energized, and energization of the electromagnetic coil ( 370 ) causes the second clutch rotor ( 350 ) to move from the disengaged position toward the engaged position. 
     
     
         17 . A lubrication system ( 300 ) for a transfer case ( 120 ,  200 ), comprising:
 a shaft ( 302 ) having a lubricant inlet port ( 306 ) and a hollow bore ( 304 ) for transporting lubricant within the shaft ( 302 );   a pump ( 310 ) having a pump housing ( 312 ) and one or more pumping elements ( 318 ) that are disposed in the pump housing ( 312 );   a first clutch rotor ( 340 ) that is disposed on the shaft ( 302 ) and is connected to the one or more pumping elements ( 318 ) such that rotation of the first clutch rotor ( 340 ) causes operation of the one or more pumping elements ( 318 ) of the pump ( 310 );   a second clutch rotor ( 350 ) that rotates in response to rotation of the shaft ( 302 ) and has an engaged position, in which rotational force from the shaft ( 302 ) is transferred to the first clutch rotor ( 340 ) to cause operation of the pump ( 310 ), and a disengaged position, in which rotational force from the shaft ( 302 ) is not transferred to the first clutch rotor ( 340 ); and   an electromagnetic coil ( 370 ) that is operable to produce a magnetic field when energized and disposed on either an axial face ( 348 ) of the first clutch rotor ( 340 ) or an axial face ( 356 ) of the second clutch rotor ( 350 ), wherein energization of the electromagnetic coil ( 370 ) causes the second clutch rotor ( 350 ) to move between the engaged position and the disengaged position.   
     
     
         18 . The lubrication system ( 300 ) of  claim 17 , energization of the electromagnetic coil ( 370 ) causes the second clutch rotor ( 350 ) to move from the engaged position toward the disengaged position. 
     
     
         19 . The lubrication system ( 300 ) of  claim 17 , energization of the electromagnetic coil ( 370 ) causes the second clutch rotor ( 350 ) to move from the disengaged position toward the engaged position. 
     
     
         20 . The lubrication system ( 300 ) of  claim 17 , wherein the electromagnetic coil ( 370 ) causes the second clutch rotor ( 350 ) to move in a first direction between the engaged position and the disengaged position, and a biasing element ( 360 ) causes the second clutch rotor ( 350 ) to move in a second direction between the engaged position and the disengaged position.