MICRO-SIZED FLUID METERING PUMP
First Claim
1. A motor-driven fluid pump having a fixed manifold connected into a fluid flow system, the pump comprising:
- a positive displacement rotary pumping element driven by said motor;
a circular, rotating cam carried radially outwardly of the pumping element and eccentrically thereto, and having a circular inner surface;
an electronic motor control module that receives a flow demand input signal from the fluid flow system, and whereinthe cam rotates on bearings carried on said manifold, andthe cam is rotated with the pumping element solely by contact with outer ends of a plurality of pistons carried radially by the pumping element and bearing against the inner surface of the cam.
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Abstract
A motor-driven fluid pump has a positive displacement rotary pumping element with a circular rotating cam carried outwardly of the element that is rotated with the pumping element by contact with pistons carried radially by the pumping element. The pump maintains a constant mass flow rate for a given input command by adjusting for fluid type, for measured fluid operating temperature, and for changing motor speed according to a pre-set algorithm. The motor-driven fluid pump also has the capability to maintain a constant flow output over the life of the pump by adjusting for internal wear and having the capability to predict its remaining life by comparing its current motor speed against the maximum allowable motor speed.
13 Citations
18 Claims
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1. A motor-driven fluid pump having a fixed manifold connected into a fluid flow system, the pump comprising:
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a positive displacement rotary pumping element driven by said motor; a circular, rotating cam carried radially outwardly of the pumping element and eccentrically thereto, and having a circular inner surface; an electronic motor control module that receives a flow demand input signal from the fluid flow system, and wherein the cam rotates on bearings carried on said manifold, and the cam is rotated with the pumping element solely by contact with outer ends of a plurality of pistons carried radially by the pumping element and bearing against the inner surface of the cam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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- 15. A micro-sized fluid-metering pump, the pump comprising a plurality of radially-oriented pistons carried in a rotor, a rotating circular cam carried about said rotor on a bearing eccentric of the rotor, for radially moving the pistons as the assembly of the rotor and cam rotate about their respective axes.
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17. A rotating device comprising
a rotor mounted for rotating about a first axis, a plurality of pistons carried in the rotor for rotational movement therewith and for radial movement therein between inward and outward locations in said rotor, a circular cam carried rotatably on said device and outwardly of said rotor and outwardly of said pistons but about a second axis spaced by a distance from the first axis, whereby as the rotor, pistons, and cam spin about the first and second axes, the distance between the axes and the centrifugal and hydraulic forces on the pistons cause the pistons to move outwardly and inwardly with respect to the rotor as the rotor, pistons, and cam rotate substantially together about their offset axes but with minimal movement between each piston and the interior surface of the cam apart from start-up, shut-down, and other rotational speed changes of the rotor.
Specification