Patent ID: 8954245
Filing Date: 2015-02-10
Classification: E02F,F16H,Y10T

Abstract:
1. A method of controlling a gear ratio rate of change in a machine having a continuously variable transmission that includes a variable displacement pump fluidly connected to at least one variable displacement motor, the method comprising steps of: moving an operator input device to indicate a desired travel direction; receiving electronic data indicative of the desired travel direction with an electronic controller; determining a non-limited desired gear ratio based at least in part on the desired travel direction with the electronic controller; determining if a change in travel direction is requested by comparing the non-limited desired gear ratio to a previous desired gear ratio; selecting a maximum gear ratio rate of change corresponding to the non-limited desired gear ratio and an actual gear ratio of the continuously variable transmission from an electronically stored gear ratio rate map of the electronic controller; determining a current desired gear ratio based at least in part on the previous desired gear ratio and the maximum gear ratio rate of change with the electronic controller; and changing a commanded gear ratio of the continuously variable transmission to the current desired gear ratio using electronic signals of the electronic controller; wherein a current gear ratio of the continuously variable transmission is represented by a current pump displacement and a current motor displacement, and wherein performing the steps of selecting the maximum gear ratio rate of change, determining the current desired gear ratio, and changing the commanded gear ratio is responsive to a change in travel direction request from a forward travel direction to a reverse travel direction or the reverse travel direction to the forward travel direction.