Patent ID: 8984872
Filing Date: 2015-03-24
Classification: G01M

Abstract:
1. A method for estimating a fluid charge of a hydraulic accumulator in a hydraulic fan circuit including a primary pump, a motor selectively fluidly connected to the pump, and drivingly connected to a fan, comprising: determining, at a microprocessor, a first accumulator pressure at a first time with a pressure sensor, the first time being during accumulator charging, determining, at the microprocessor, a second accumulator pressure at a second time with the pressure sensor, the second time being during accumulator charging, determining, at the microprocessor, a first fan speed at the first time, determining, at the microprocessor, a second fan speed at the second time, estimating, at the microprocessor, the fluid charge of the hydraulic accumulator as a function of the first accumulator pressure, the second accumulator pressure, the first fan speed, and the second fan speed, and controlling, using the microprocessor, the hydraulic fan circuit based upon said estimating.