Adaptive clutch slip learning for critical capacity clutch fusing in a continuously variable transmission

• Main Authors: Daavettila, Chet, Abington, James L, Stockdale, Timothy R, Li, Dongxu, Hultengren, Colin
• Format: Patent
• Language: English
• Published: 05.06.2018
• Subjects: BLASTING; BRAKES; CLUTCHES; COUPLINGS FOR TRANSMITTING ROTATION; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; THERMAL INSULATION IN GENERAL; WEAPONS

A continuously variable transmission, a control system, and a method are provided. The control system and method are configured to learn a desired running pressure to be applied to a clutch that is lower than a pulley clamping pressure and higher than a pressure at which the clutch would slip (a clutch critical pressure), so that the clutch can act as a fuse to avoid pulley slip. A plurality of clutch slip tests are performed, each of which include decreasing pressure supplied to the clutch until a clutch slip occurs. Clutch slip data points are collected at the point of slip and used to determine a gain and an offset, where the gain is a clutch pressure versus clutch torque capacity gain, and the offset is a clutch pressure offset, which is used to determine the clutch critical pressure.