The returning place force of equilibrium valve is by the combined method of sealing load and spring force stack
Technical field:
The present invention relates to a kind of equilibrium valve main valve plug and close the composing method of returning place force.
Technical background:
At present, the composing method of the throttle valve main valve plug returning place force of equilibrium at home and abroad valve has two kinds: a kind of is that the chamber is communicated with and communicates with its import before and after the main valve plug, and the returning place force of main valve plug is produced by pressure spring fully; Another kind is that the back cavity of main valve plug is communicated with hyperbaric chamber, forms returning place force by sealing load and spring.As fully visible: first kind of equilibrium valve main valve plug close returning place force in its working procedure by the pressure spring effect.Therefore reflect that in actual use equilibrium valve product just normal appearance cause occurring performance variation because of camber of spring and fatigue, sealing reliability is poor, and the life-span is short.Then the pressure participation active area because of the main valve plug sealing is too big for second kind of returning place force composing method, and causes the damage of potted line on the sealing seat, and the impact force that the instantaneous pressure of especially closing causes is destroyed bigger to potted line.Normal sealing life and the integrity problem that occurs of first method can appear equally.
Goal of the invention:
The objective of the invention is to invent and a kind ofly can overcome the deficiency that above-mentioned two kinds of equilibrium valves cut out the returning place force composing method, propose a kind ofly brand-new to be superimposed to form the method that equilibrium valve cuts out returning place force by sealing load that acts on the little annulus area and spring force.
Technical solution:
Technical solution of the present invention is the diameter that the sealed mouth diameter with main valve plug is designed to be slightly larger than the motive sealing assembly department that main valve plug Seal cage and its back cavity separate, and adds a middle cover between the motive sealing assembly department of main valve plug and valve pocket or valve body.The external diameter of this cover is greater than the external diameter of main valve plug, and internal diameter cooperates with main valve plug motive sealing assembly department.Because of the sealed mouth exocoel and the connection of its back cavity of main valve plug all do not have the high pressure effect, like this by on the formed little annulus area of the diameter difference of sealed mouth diameter and motive sealing assembly department, the pressure oil effect of main valve plug Seal cage is just arranged, produce a active force towards the main valve plug closing direction, this active force with act on spring force stack on the main valve plug and formed the returning place force of closing of equilibrium valve.
Description of drawings:
Accompanying drawing 1 is that restriction of the present invention is arranged on the structural drawing on the main valve plug.
Accompanying drawing 2 is that restriction of the present invention is provided with the structural drawing on the nonreturn valve core.
Mode of execution:
The specific embodiment of the present invention 1 is described as follows in conjunction with the accompanying drawings: the sealed mouth slightly larger in diameter of main valve plug 6 is in O shape circle 9 motion sealing assembly department diameters, and this motive sealing assembly department is contained in the endoporus of middle cover 8 and cooperates with it.Equilibrium valve A mouth in system connects selector valve, weight is transferred, the A chamber is the logical oil return of low-pressure cavity during equilibrium valve work, it is hyperbaric chamber that the B mouth connects oil hydraulic motor, this moment, no matter whether restriction was opened, by main valve plug sealed mouth diameter and the formed annulus area of its motive sealing assembly department diameter difference the high pressure oil effect in B chamber is arranged all, produce a pressure that makes main valve plug towards closing direction, the returning place force of closing of equilibrium valve has been formed in the compressive tension stack of it and spring 11.This method is because there is a hydraulic coupling that is directly proportional with the B cavity pressure to participate in forming the returning place force of closing of equilibrium valve, it has guaranteed that the return sealing force of main valve plug can be because of camber of spring or tired the influence, and only can improve with the increase of sealed pressure, guaranteed the every dynamic performance and the sealing life of equilibrium valve.Very little because participate in the area of high pressure effect again simultaneously, so it can not produce too big pressure and bump to sealing seat, and guarantee to seal the intensity of paying.Especially accompanying drawing 1 this one-way valve and main valve plug are inside and outside sleeve structure, and it has also ensured the Strength Safety that the one-way valve sealing is paid.