Abstract: A compact scroll fluid device includes a pair of wrap support elements with one of the wrap support elements having an inner axial surface formed with an involute spiral recess and the other of the wrap support elements having an involute spiral wrap member projecting from an inner axial surface thereof. The spiral wrap member is received within the spiral recess while being relatively movable about an orbital path therein. A synchronizer assembly is provided axially between the wrap support elements, radially inwardly of both inlet and outlet zones associated with the scroll fluid device and radially outwardly of an orbit center of the device. The entire scroll fluid device is preferably made of plastic. With this arrangement, an extremely compact and inexpensive device is provided.

Abstract: A sensing unit includes a re-usable portion which is isolated from system fluids and a disposable portion. The disposable portion includes an enclosure that defines an internal cavity with one wall of the enclosure being constituted by a flexible diaphragm that is exposed to operating pressure of the system. The re-usable portion has mounted therein a sensing array at a position adjacent to a non-system pressure side surface of the diaphragm. The sensing array includes a plurality of sensing elements which are arranged as radial inner and outer sets with each set being adapted to preferentially sense a deflection of a central portion of the diaphragm. An output signal representative of the fluid pressure in the fluid system is established based on a ratio of deflection signals from the sets of sensing elements. Preferably, the sensing elements constitute capacitive plates that have equally exposed surface areas.