Apparatus to bias spool valves using supply pressure

摘要

Methods and apparatus to bias spool valves using supply pressure are disclosed. An example apparatus includes a housing of a spool valve, the housing including a first port to receive a fluid at a supply pressure. The example apparatus further includes a spool within the housing. A position of the spool is to be selectively controlled via an input force acting on the spool, the position of the spool to define a path of a flow of the fluid through the spool valve from the first port to a second port of the housing. A biasing force is to bias the spool opposite the input force, the biasing force to be generated from the supply pressure applied to an end of the spool.

主权项

1. An apparatus comprising:
a housing of a spool valve, the housing including a first port to receive a fluid at a supply pressure; a spool within the housing, a position of the spool to be selectively controlled via an input force acting on a first end of the spool, the position of the spool to define a path of a flow of the fluid through the spool valve from the first port to a second port of the housing, wherein a biasing force, acting on a second end of the spool, is to bias the spool opposite the input force, the biasing force to be generated from the supply pressure applied to the second end of the spool, the input force to be generated from an input pressure applied to the first end of the spool, the input pressure corresponding to a proportion of the supply pressure, the proportion to be less than the supply pressure; a current-to-pressure converter to define the proportion of the supply pressure corresponding to the input pressure based on an electrical control signal; and fluid lines to separately guide the fluid (1) indirectly to the first end of the spool via the current-to-pressure converter, (2) directly to the second end of the spool to continuously provide the biasing force when the fluid at the supply pressure is supplied, and (3) directly to the first port of the housing of the spool valve.