NZ773577A - A fluid circuit device - Google Patents

Abstract

A method of controlling pressure variation in working fluids in a fluid circuit undergoing working pressure variation, the method comprising: selecting a fluid circuit device, wherein the fluid circuit device is configured to be integrated into an energy absorption apparatus, and wherein the fluid circuit device comprises: at least one first fluid volume and at least one second fluid volume, and at least one pressure balancing valve in a valve housing, wherein the fluid circuit device is used about a piston comprising opposing sides and which moves in a cylinder, wherein when the piston moves in the cylinder a pressure change occurs with fluid on one side of the piston having a higher pressure than fluid on the opposing side of the piston, wherein the at least one pressure balancing valve is located across the opposing sides of the piston between the at least one first fluid volume and the at least one second fluid volume such that flow of fluid from either side of the piston is directed by the at least one pressure balancing valve, and wherein the at least one first fluid volume and at least one second fluid volume are on either side of the at least one pressure balancing valve operatively linked via a pressure varying relationship, wherein the at least one pressure balancing valve fluidly links the at least one first fluid volume and the at least one second fluid volume with a common third fluid volume; in use, when there is a pressure difference between the at least one first fluid volume and the at least one second fluid volume caused by piston movement of the piston, the at least one pressure balancing valve actuates on application of a pressure gradient relative to the at least one first fluid volume and the at least one second fluid volume, the at least one pressure balancing valve changing position in the valve housing to: provide a fluid flow path between the common third fluid volume and a lower pressure of either the at least one first fluid volume or the at least one second fluid volume; and restricts or closes a fluid flow path between the common third fluid volume and a higher pressure of either the at least one first fluid volume or the at least one second fluid volume; wherein, in the event of a low or no pressure gradient between the at least one first fluid volume and the at least one second fluid volume, the at least one pressure balancing valve permits connection between the at least one first fluid volume and the at least one second fluid volume via the common third fluid volume, thereby allowing equilibration of pressure across all volumes in the fluid circuit device; and wherein the fluid circuit device is a closed circuit; and integrating the device into an apparatus configured to undergo pressure variation.