Rotary drag valve
A valve assembly comprising a rotary closure element which defines an axis of rotation and is selectively movable between a fully open position and a fully closed position. Mounted to and movable with the rotary closure element is an impedance assembly. The impedance assembly defines an inflow end and an outflow end, and comprises a plurality of fluid passageways of varying noise attenuating capability which extend from the inflow end to the outflow end. Also partially defined by the impedance assembly is a flow opening which extends from the inflow end to the outflow end. A retainer bracket is disposed within the flow opening and is cooperatively engaged to both the closure element and the impedance assembly.
1. A valve assembly comprising:
a rotary closure element defining an axis of rotation and selectively movable between a fully open position and a fully closed position;
an impedance assembly mounted to and movable with the rotary closure element, the impedance assembly defining an inflow end and an outflow end, and comprising:
a plurality of noise attenuating fluid passageways extending from the inflow end to the outflow end;
the impedance assembly and the closure element collectively defining a flow opening which extends from the inflow end to the outflow end;
a retainer bracket disposed within the flow opening and cooperatively engaged to the closure element and the impedance assembly.
2. The valve assembly of claim 1 wherein the retainer bracket defines a peripheral side surface having a configuration which is complementary to the profile of the flow opening.
3. The valve assembly of claim 1 wherein:
the rotary closure element includes an elongate slot formed therein; and
the impedance assembly includes a rib protruding therefrom having a configuration which is complementary to the slot;
the impedance assembly being mounted to the closure element such that the rib is advanced into the slot.
4. The valve assembly of claim 1 wherein:
at least some of the fluid passageways are tortuous and define a series of turns which extend at generally right angles relative to each other; and
the tortuous fluid passageways of the impedance assembly define differing numbers of turns.
5. The valve assembly of claim 4 wherein the impedance assembly is mounted to the closure element such that flow is applied initially to the tortuous passageways having a greater number of turns when the closure element is moved from the fully closed position toward the fully open position.
6. The valve assembly of claim 1 wherein:
the closure element defines an arcuate outer surface;
the impedance assembly is configured in a manner wherein the outflow end is arcuately contoured; and
the impedance assembly is mounted to the closure element such that the arcuate outflow end of the impedance assembly is substantially continuous with the outer surface of the closure element.
7. A valve assembly, comprising:
a rotary closure element defining an axis of rotation and selectively movable between a fully open position and a fully closed position, the closure element including an inner surface which defines a bore and has an elongate slot disposed therein; and
an impedance assembly mounted within the bore and movable with the rotary closure element, the impedance assembly defining an inflow end, an outflow end, an inner surface, an outer surface, and comprising:
a plurality of noise attenuating fluid passageways extending from the inflow end to the outflow end; and
an elongate rib extending from the outer surface, the rib having a configuration which is complementary to the slot and being inserted therein;
the inner surfaces of the impedance assembly and the closure element collectively defining a flow opening which extends from the inflow end to the outflow end.
8. The valve assembly of claim 4 further comprising a retainer bracket disposed within the flow opening and cooperatively engaged to the inner surfaces of the impedance assembly and the closure element.
9. The valve assembly of claim 8 wherein the retainer bracket defines a peripheral side surface having a configuration which is complementary to the profile of the flow opening.
10. The valve assembly of claim 7 wherein:
at least some of the fluid passageways are tortuous and define a series of turns which extend at generally right angles relative to each other; and
the tortuous fluid passageways of the impedance assembly define differing numbers of turns.
11. The valve assembly of claim 10 wherein the impedance assembly is mounted to the closure element such that flow is applied initially to the tortuous passageways having a greater number of turns when the closure element is moved from the fully closed position toward the fully open position.
12. The valve assembly of claim 7 wherein:
the closure element defines an arcuate outer surface;
the impedance assembly is configured in a manner wherein the outflow end is arcuately contoured; and
the impedance assembly is mounted to the closure element such that the arcuate outflow end of the impedance assembly is substantially continuous with the outer surface of the closure element.