Abstract: Generally stated, various embodiments described herein concern a toroidal CVT provided with parking zones where the rollers are brought when the CVT is powered down. More specifically, a portion of the toroidal surfaces of the disks is reserved as a parking zone therefore preventing premature wear and/or damages to the working portion of the disks.
Type:
Grant
Filed:
March 26, 2012
Date of Patent:
October 4, 2016
Assignee:
TRANSMISSION CVTCORP INC.
Inventors:
Samuel Beaudoin, Christian McMahon, Paul Okulov
Abstract: An apparatus for controlling a variator having at least one roller between two torroidal disks may include at least one actuator responsive to fluid pressure at separate high side and low side fluid inlets thereof to control torque applied by the at least one roller to the disks. First and second variator switching valves may each receive a first fluid at a first pressure and a second fluid at a second lesser pressure. The first and second variator switching valves supply the first fluid to the high side fluid inlet and the second fluid to the low side fluid inlet during two of four different operational states together defined by the variator switching valves, and supply the second fluid to the high side fluid inlet and the first fluid to the low side fluid inlet during each of the remaining two of the four different operational states.
Type:
Application
Filed:
December 14, 2011
Publication date:
August 9, 2012
Inventors:
Charles F. Long, Darren J. Weber, John W.E. Fuller
Abstract: An oil pressure control apparatus includes a belt-driven continuously variable transmission, a primary regulator valve that regulates a line oil pressure that becomes a source pressure of oil pressure of various parts, and a gear oil pressure control valve that supplies gear oil pressure to a driving-side pulley of the belt-driven continuously variable transmission. A failsafe valve is provided between the gear oil pressure control valve and the driving-side pulley. When the gear oil pressure control valve or a linear solenoid valve that controls the gear oil pressure control valve fails, the failsafe valve is switched so as to supply the line oil pressure to the driving-side pulley, and other than during such the gear oil pressure control valve's failure or the electromagnetic valve's failure, the failsafe valve is switched so as to supply the gear oil pressure to the driving-side pulley.
Abstract: A pivotal feedback line has at one end thereof a follower member that is slidably put on a work surface of a precess cam actuated by a trunnion of a toroidal type continuously variable transmission. A speed control valve has a spool. The spool is moved for feeding a hydraulic actuator of the transmission with a hydraulic pressure to control the trunnion. An electric actuator has an output member. A speed change link is arranged to which the other end of the pivotal feedback link, the spool of the speed control valve and the output member of the electric actuator are connected through first, second and third articulated members respectively.
Abstract: A speed ratio of a continuously variable transmission is varied according to an oil pressure which is adjusted by a valve driven by a step motor. The step motor is feedback controlled so that a real speed ratio coincides with a target speed ratio determined according to the running conditions of a vehicle. By determining a feedback gain based on the oil pressure, oil temperature, real speed ratio and output shaft rotation speed of the transmission, precise control of the speed ratio according to the running state is realized.