Patent ID: 9482365
Filing Date: 2016-11-01
CPC Classification: F16K,Y10T

Claim Text:
1. A rotary valve comprising: a housing having a cavity; a rotary spool positioned within and rotatably movable in the cavity of the housing about a rotation axis, the spool having a fluid passageway extending through the spool between first and second openings at an outer radial surface of the spool; wherein the housing has four flow ports including first and second flow ports opening to the cavity at radially spaced apart locations that respectively will align with the first and second openings at the outer radial surface of the spool at a first rotated position of the rotary spool, a first balancing port opening to the cavity at a side of the cavity radially opposite the first flow port, and a balancing passageway outside of the valve spool for communicating fluid pressure from the first flow port to the first balancing port, wherein the rotary spool is moveable to a first position to create a fluid passageway between the first flow port and the second flow port, a second position to create a fluid passageway between a third flow port and a fourth flow port, and a third position blocking flow through the valve, wherein the housing includes a second balancing port opening to the cavity at a side of the cavity radially opposite the first flow port and a balancing passageway outside of the valve spool for communicating fluid pressure from the first flow port to the second balancing port, and wherein the first and second balancing ports are axially offset from the first flow port and have a combined opening area approximately equal to the opening area of the first flow port, thereby reducing net torque applied to the rotary spool when pressurized.