Continuously variable transmissions and methods therefor

Abstract

Inventive embodiments are directed to components, subassemblies, systems, and/or methods for continuously variable transmissions (CVT) having a variator provided with a plurality of tilting, traction planets and traction rings. In one embodiment, a variator is coupled to a rangebox to provide multiple operating modes. In another embodiment, a hydraulic system is configured to control the transmission ratio of the variator and the rangebox. Various inventive shift-cam-and-sun subassemblies can be used to facilitate shifting of the transmission ratio of a CVT. Embodiments of a transmission housing and bell housing are adapted to house components of a CVT and, in some embodiments, to cooperate with other components of the CVT to support operation and/or functionality of the CVT. Various related devices include embodiments of, for example, a pivot arm, a control feedback mechanism, axial force generation and management mechanisms, a control valve integral with an input shaft, a pivot pin hub, and a rotatable carrier configured to support planet-pivot arm assemblies. FIG. 72 shows a torque-split ball-type rolling traction CVT with a ball-type rolling traction variator ( 1200 ) and planetary gearset ( 1400 ) which is followed by a rangebox ( 1600 ).

1 . A drive comprising:
 a prime mover; and   a transmission coupled to the prime mover, wherein the transmission comprises:   a continuously variable unit (CVU);   an input interface coupled to the prime mover and to the CVU;   an output interface coupled to the CVU; and   a parallel branch for mechanical power transmission, said parallel branch coupled to the input interface and to the output interface.   
   
   
       2 . The drive of  claim 1 , wherein the CVU comprises a plurality of spherical traction rollers. 
   
   
       3 . The drive of  claim 2 , further comprising a lubrication system operably coupled to the CVU, the lubrication system configured to provide a lubricant to the spherical traction rollers. 
   
   
       4 . The drive of  claim 2 , wherein the transmission further comprises a rangebox coupled to the output interface. 
   
   
       5 . The drive of  claim 4 , wherein the output interface comprises a combining device. 
   
   
       6 . The drive of  claim 5 , wherein the combining device comprises a planetary gearset. 
   
   
       7 .- 14 . (canceled) 
   
   
       15 . A transmission comprising:
 a plurality of traction rollers;   a carrier assembly operably coupled to the traction rollers;   an input element configured to transfer torque to the traction rollers, the input element comprising:   a load cam having bidirectional load cam ramps;   a traction ring having bidirectional load cam ramps;   an output element configured to transfer torque from the traction rollers;   a shifter assembly configured to adjust an axis of rotation of the traction rollers;   a hydraulic system operably coupled to the shifter assembly; and   a lubrication system configured to provide lubricant to at least the traction rollers.   
   
   
       16 . The transmission of  claim 15 , wherein the hydraulic system comprises at least one hydraulic piston. 
   
   
       17 . The transmission of  claim 16 , wherein the shifter assembly comprises at least one shift cam, and wherein the at least one hydraulic piston is operationally coupled to the at least one shift cam. 
   
   
       18 . (canceled) 
   
   
       19 . The transmission of  claim 15 , wherein the output element comprises a load cam. 
   
   
       20 . The transmission of  claim 19 , wherein the load cam comprises bidirectional ramps. 
   
   
       21 .- 39 . (canceled) 
   
   
       40 . A transmission comprising:
 a plurality of spherical traction rollers;   a carrier assembly for supporting the traction rollers;   an input element for transferring torque to the traction rollers;   an output element for transferring torque from the traction rollers;   an axial force generator for applying a clamping force to the spherical rollers, input element, and output element;   a shifter assembly for adjusting an axis of rotation of the spherical traction rollers;   a hydraulic system for actuating the shifter assembly; and   a lubrication system for providing lubricant to at least the spherical traction rollers.   
   
   
       41 .- 43 . (canceled) 
   
   
       44 . The transmission of  claim 40 , wherein the output element comprises a load cam. 
   
   
       45 . The transmission of  claim 44 , wherein the load cam comprises bidirectional ramps. 
   
   
       46 .- 50 . (canceled) 
   
   
       51 . The transmission of  claim 40 , further comprising an input interface coupled to the input element. 
   
   
       52 . The transmission of  claim 51 , further comprising an output interface coupled to the output element. 
   
   
       53 . The transmission of  claim 52 , further comprising a parallel branch coupled to the input interface and to the output interface. 
   
   
       54 .- 103 . (canceled) 
   
   
       104 . A center manifold for a continuously variable unit (CVU), the center manifold comprising:
 a base plate having a plurality of channels and ports for receiving and distributing control fluid and lubricant; and   a cover plate adapted to couple to the base plate, the cover plate having a plurality of channels and ports for receiving and distributing control fluid and lubricant.   
   
   
       105 . The center manifold of  claim 104 , further comprising a plurality of recess for clearing a plurality of traction planets of the CVU. 
   
   
       106 . The center manifold of  claim 104 , further comprising at least one structure for locating the center manifold in a housing of the CVU. 
   
   
       107 .- 217 . (canceled)