Patent ID: 9091262
Filing Date: 2015-07-28
Classification: F04B,F15B

Abstract:
1. A system, comprising: a hydraulic fluid consuming device; a hydraulic pump unit that provides hydraulic fluid to the hydraulic fluid consuming device, the hydraulic pump unit including a pump unit and at least one accumulator that are configured to deliver the hydraulic fluid to the hydraulic fluid consuming device; a wattmeter that measures the electric power consumption by the hydraulic pump unit during a transient-state start-up operation in which the hydraulic pump unit turns on to deliver the hydraulic fluid to the hydraulic fluid consuming device and thereafter replenish the accumulator for a predetermined amount of time; and a controller that uses the electric power consumption measured by the wattmeter during the transient-state start-up operation to determine fluid flow parameters from the operation of the pump unit and the at least one accumulator, wherein the fluid flow parameters comprise power delivered to the hydraulic fluid by the hydraulic pump unit and volumetric flow rates, the controller determining the power delivered to the hydraulic fluid by the hydraulic pump unit by reference to power consumption that occurs above a minimum trigger power level, the minimum trigger power level representing a minimum power difference above a floor power level that represents the transient-state start-up operation and which indicates that the hydraulic fluid consuming device is starting to consume hydraulic fluid, wherein the controller determines a plurality of diagnostics for the hydraulic fluid consuming device and the hydraulic pump unit as a function of the fluid flow parameters, including estimating an internal pressure and hydraulic storage amount of the at least one accumulator using a polytropic gas relationship and the predetermined amount of time, respectively, which estimate the at least one accumulator's condition relative to an initial internal pressure and available hydraulic fluid storage amount of the at least one accumulator.