Patent ID: 7993225
Filing Date: 2011-08-09
Classification: F16H

Abstract:
1. A hydraulic pressure supply unit of a continuously variable transmission that includes a primary pulley and a secondary pulley each holding a transmission member transmitting power, and a friction engagement element to which a hydraulic pressure is supplied for engagement to transmit, to a wheel, power output from a driving source, and changes a gear ratio in accordance with the hydraulic pressure supplied to said primary pulley, said hydraulic pressure supply unit comprising: a first oil passage to which a hydraulic pressure obtained by decreasing a line pressure is supplied; a second oil passage to which a hydraulic pressure controlled by a first solenoid valve is supplied; a third oil passage to which a hydraulic pressure controlled by a second solenoid valve is supplied; a fourth oil passage for supplying a hydraulic pressure to said secondary pulley; a fifth oil passage for supplying a hydraulic pressure to said friction engagement element; a sixth oil passage for supplying a hydraulic pressure to said primary pulley; and a switching valve for switching between a first state where said fifth oil passage is in communication with said first oil passage and interrupted from said second oil passage, and said sixth oil passage is in communication with said third oil passage and interrupted from said fourth oil passage, and a second state where said fifth oil passage is in communication with said second oil passage and interrupted from said first oil passage, and said sixth oil passage is in communication with said fourth oil passage and interrupted from said third oil passage, said fourth oil passage having an orifice.