| 摘要 |
A hydraulic fuse monitors the quantity of hydraulic fluid passing through the fuse, and then blocks such flow when a selected quantity of fluid has passed through the fuse. It includes: (a) a body structure containing cavity structure, (b) a primary piston in the cavity structure and movable endwise to control fluid flow through a first port, (c) a sleeve, and a sleeve guide in the cavity structure, and in the path of fluid flow toward the primary piston, (d) the sleeve and guide being relatively axially movable, and there being a spring acting to urge one of the sleeve and guide in one axial direction, (e) and fluid flow control slots formed by the sleeve and sleeve guide to control flow both to the piston for controllably displacing same, and to the first port, and characterized in that: (i) as the forward flow rate through the fuse reaches a threshold the piston begins its movement toward the first port, and (ii) as the flow rate increases above the threshold, relative axial movement between the sleeve and guide acts: to maintain nearly constant, the fluid pressure drop across a primary slot included with the control slots; and to controllably meter fluid flow to the piston via a metering slot included within the control slots, for displacing the first piston as aforesaid, (f) whereby the piston is displaced to close the first port after a required quantity of fluid has passed through the fuse.
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