US 4,043,714 AGranted

Seal grid assembly for rotary piston mechanism

AssigneeCurtiss-Wright Corporation

InventorMurray Berkowitz

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Abstract

The improved seal grid assembly is for a rotary compressor or expansion engine of the type having a rotor supported for planetation in a multi-lobe housing cavity and comprises, in combination with a non-rotating seal at the juncture of the housing lobes, a sealing means including a sealing surface movable between a retracted position where it is out of engagement with the peripheral wall and an extended position where it is in engagement with the peripheral wall of the housing cavity. A vent passage means is also provided in the rotor to communicate a space defined between the sealing means and rotor with the working chambers to conduct gaseous fluid which pressurizes said space so as to provide movement of the sealing surface of the associated seal means to the retracted position just prior to engagement with the non-rotating seal and to the extended position after such engagement with the non-rotating seals at each of the housing lobe junctures.

An improved seal grid assembly for rotary piston mechanisms, having a housing with axially spaced end walls and a peripheral wall interconnecting the end walls to form a multi-lobed cavity therebetween and having a rotor mounted within said cavity for rotation on an axis eccentric to the housing cavity axis, the rotor having opposite end faces adjacent the housing end walls and a plurality of flank surfaces converging with each other to form a plurality of circumferentially spaced apex portions so that the rotor defines with the housing walls a plurality of working chambers which vary in volumetric size and gaseous fluid pressure as the rotor rotates within the housing cavity, the improved seal grid assembly comprises, in combination with a seal blade means at each of the junctures of the housing cavity lobes;

a. a flexible plate seal carried in each of the apex portions of the rotor;
b. each of said flexible plate seals includes a sealing surface movable between a retracted position where it is out of engagement with the peripheral wall and an extended position where it is in engagement with the peripheral wall;
c. each of said flexible plate seals and its associated apex portion of the rotor defining a space therebetween;
d. a mechanical biasing means acting on the flexible plate seal to exert a force on the latter in a direction to urge the sealing surface in a retracted position;
and
e. passage means in said rotor for each of said flexible plate seals communicating the associated space with the working chambers to conduct gaseous fluid to and from the working chambers and thereby allow movement of an associated flexible plate seal to the retracted position under the urging of the biasing means just prior to engagement with a non-rotating seal element at each of the lobe junctures and to effect movement to the extended position for re-engagement with the peripheral wall after such engagement with each of said non-rotating seal elements at the lobe junctures.

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Abstract

Claims13