What is it on an excavator that determines auxiliary flow and how does that work? If an excavator has for example, 100 gpm main pump but only 59 gpm auxiliary flow, what is it in the 'system' that restricts or dedicates 59 gpm to the auxiliary? Just trying to learn more about these machines. Thanks
Good day The most common method to control flow on modern machines is to use a solenoid valve to adjust the pump regu;ation, thus when the option line is activated the pump flow is automatically reduced. Older principles worked with some form of restriction. Kind regards uffex
On an open center hydraulic system in medium sized and larger excavators usually runs on two sections in a pump or two complete pumps. Each pump supplies oil to one section or half of a two section hydraulic valve with multiple spools for directional control. The valve feeding the auxiliary function will run on only one pump that way. When something needs high flow two spools will be open at the same time and a cross over valve allows oil from both pumps to feed both sections of the directional control valve. On a closed section the size of the ports inside the auxiliary valve are limited so that only the flow amount of one pump can get through that valve.