Control system for a continuously variable transmission

Patent · Tue Nov 03 04:00:00 EST 1987

OSTI ID:5803529

Sakai, Y

This patent describes a control system for a continuously variable belt-drive transmission having a selector device including a drive range position, a drive pulley having a hydraulically shiftable disc and a servo chamber for shifting the disc, a driven pulley having a hydraulically shiftable disc and a servo chamber for shifting the disc, and a belt engaged with both the pulleys, an hydraulic control circuit for supplying oil to the servo chambers and for draining the servo chambers, the hydraulic control circuit being provided with a pressure regulator valve for providing a line pressure and a transmission ratio control valve for applying the line pressure to the servo chamber of the drive pulley. The improvement comprises: a first drain passage from the pressure regulator valve; a second drain passage from the transmission ratio control valve; a first check valve provided in the first drain passage and a second check valve provided in the second drain passage for building up supplementary low pressure in both drain passages at upstream of both the check valves; a supplementary oil passage communicating both the first and second drain passages at upstream of the check valves for supplying a part of drain oil to the servo chamber of the drive pulley.

• Assignee: Fuji Jukogyo Kabushiki Kaisha, Tokyo
• Patent Number(s): US 4704097
• OSTI ID: 5803529
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330602* -- Vehicle Design Factors-- Engine-Transmission Matching
CONTROL
CONTROL EQUIPMENT
CONTROL SYSTEMS
EQUIPMENT
FLOW REGULATORS
FLUID MECHANICS
HYDRAULIC EQUIPMENT
HYDRAULICS
MACHINE PARTS
MECHANICAL TRANSMISSIONS
MECHANICS
OPERATION
PRESSURE CONTROL
SERVOMECHANISMS
VALVES