Continuously variable transmission

Abstract

Embodiments are directed to a front end accessory drive (FEAD) and power modulating devices (PMD) which can be used in a FEAD. In one embodiment, a continuously variable transmission (CVT) is coupled directly to a crankshaft of a prime mover, and the CVT is used to regulate the speed and/or torque delivered to an accessory. A compound drive device includes a motor/generator subassembly cooperating with a CVT subassembly to provide a motor functionality with torque multiplication or division, or alternatively, a generator functionality with torque multiplication or division. In some embodiments, a FEAD includes a PMD having a sun shaft configured to couple to a sun of the PMD and to an electric motor component, such as an electrical armature or an electrical field. In one embodiment, the electrical armature the electrical field are placed concentrically and coaxially and configured to rotate relative to one another in opposite directions.

What we claim is: 
     
         1 . A front end accessory drive (FEAD) system in a case of a vehicle, the FEAD comprising:
 a variator comprising
 a plurality of spherical planets arranged around a shaft defining a longitudinal axis, each spherical planet rotatable about a ball axle in a central bore, the ball axle defining a tiltable axis of rotation, 
 a first traction ring positioned on a first side of, and in contact with, the plurality of spherical planets, 
 a second traction ring positioned on a second side of, and in contact with, the plurality of spherical planets, and 
 a sun positioned radially inward of and in contact with the plurality of spherical planets; and 
   a lubrication system including a scraper for directing a flow of lubricant to one or more components within the case.   
     
     
         2 . The FEAD of  claim 1 , wherein the lubrication system is configured to direct lubricant toward one or more of the sun, the first traction ring, the second traction ring, the plurality of spherical planets, and the ball axles of the variator. 
     
     
         3 . The FEAD of  claim 2 , wherein the ball axles comprise grooves configured for directing lubrication inside the central bores of the plurality of spherical planets. 
     
     
         4 . The FEAD of  claim 1 , wherein the scraper is integrated with a spacer. 
     
     
         5 . The FEAD of  claim 4 , wherein the spacer has a passage, and wherein the scraper is configured to direct lubricant to the passage. 
     
     
         6 . The FEAD of  claim 4 , wherein the scraper is formed from a different material than the spacer. 
     
     
         7 . The FEAD of  claim 1 , wherein the scraper is formed from rubber. 
     
     
         8 . The FEAD of  claim 1 , further comprising a control mechanism for controlling the ratio of the variator. 
     
     
         9 . The FEAD of  claim 8 , wherein the control mechanism comprises a stepper motor. 
     
     
         10 . The FEAD of  claim 9 , wherein the control mechanism comprises a control hardware and/or software for controlling the stepper motor. 
     
     
         11 . The FEAD of  claim 1 , wherein the sun has an outer diameter that increases at the ends of the sun, and wherein lubrication that contacts the sun is drawn to the largest diameter of the sun. 
     
     
         12 . The FEAD of  claim 11 , wherein the outer diameter of the sun is configured such that a flow of lubrication resists forces on the sun. 
     
     
         13 . The FEAD of  claim 12 , wherein the outer diameter of the sun is configured such that a flow of lubrication resists axial forces on the sun. 
     
     
         14 . The FEAD of  claim 1 , wherein the case is coupled to a stationary component of an engine. 
     
     
         15 . A drivetrain comprising:
 a front end accessory drive (FEAD) system in a case of a vehicle, the FEAD comprising
 a variator comprising
 a plurality of spherical planets arranged around a shaft defining a longitudinal axis, each spherical planet rotatable about a ball axle in a central bore, the ball axle defining a tiltable axis of rotation, 
 a first traction ring positioned on a first side of, and in contact with, the plurality of spherical planets, 
 a second traction ring positioned on a second side of, and in contact with, the plurality of spherical planets, and 
 a sun positioned radially inward of and in contact with the plurality of spherical planets; 
 
 a lubrication system including a scraper for directing a flow of lubricant to one or more components within the case; 
 an accessory for receiving power from a prime mover, the power being modulated by the variator; and 
 a control system for controlling one or more of the variator, a prime mover coupled to the variator, the accessory, and the lubrication system. 
   
     
     
         16 . The drivetrain of  claim 15 , further comprising a sensor for detecting an actual speed of the accessory. 
     
     
         17 . The drivetrain of  claim 15 , wherein the case comprises a plurality of fins. 
     
     
         18 . The drivetrain of  claim 15 , further comprising a controller comprising a proportional-differential control scheme that provides a signal to a motor controller microprocessor. 
     
     
         19 . The drivetrain of  claim 15 , wherein the control system is configured to receive and store a signal indicative of a desired accessory speed. 
     
     
         20 . The drivetrain of  claim 15 , further comprising a sensor for detecting a prime mover speed.