Compensation for a drag force generated by a rotating clutch piston seal

• Main Authors: Webert David C, Biggs Scott D
• Format: Patent
• Language: English
• Published: 07.03.2017
• Subjects: BLASTING; BRAKES; CLUTCHES; COUPLINGS FOR TRANSMITTING ROTATION; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; THERMAL INSULATION IN GENERAL; WEAPONS

A method of regulating a clutch assembly that has a set of clutch plates and a clutch piston with a fluid seal in an automatic transmission that includes a hydraulic circuit is disclosed. The method includes commanding the hydraulic circuit via the controller to apply a first hydraulic force to the clutch piston to displace the clutch piston relative to the set of clutch plates in order to affect a shift between speed-ratios in the transmission. The method also includes determining a drag force of the fluid seal. The method also includes determining a velocity of the displaced clutch piston that results from the drag force of the fluid seal acting counter to the displacement of the clutch piston. The method additionally includes regulating the clutch assembly to compensate for the determined drag force of the fluid seal acting counter to the displacement of the clutch piston.