CN2262137Y

CN2262137Y - Pressure compensation sealing device for hydraulic cylinder

Info

Publication number: CN2262137Y
Application number: CN 96226342
Authority: CN
Inventors: 李�杰; 齐洪芳
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-05-22
Filing date: 1996-05-22
Publication date: 1997-09-10
Anticipated expiration: 2006-05-22

Abstract

The utility model discloses a pressure compensation sealing device for hydraulic cylinders, which is composed of a sealing groove which is provided with oil ducts on both ends and a sealing ring which is arranged in the sealing groove. The sealing ring is composed of two sealing bodies of which the sections are respectively in an O shape and an L shape, and the two sealing bodies are connected into integration. The pressure compensation sealing device has the functions of compensating pressure and sealing in running time and has the advantage of oil tightness in stopping time. [0].

Description

A kind of cylinder pressure compensation sealing device

The utility model relates to hydraulic equipment, and particularly a kind of have a pressure compensation seal arrangement that the cross section is the seal ring of L and O shape.

In order to improve the sealability of hydraulic equipment, prolong the working life of Sealing, various cylinder pressure compensation sealing devices had appearred in recent years in succession, as Chinese patent ZL95230717, a kind of " the floating type seal arrangement of cylinder pressure self compensation " disclosed for No. 0, it is to place the end to have in the seal groove of oil duct a seal ring, the width of seal groove and the degree of depth are respectively greater than the width and the thickness in seal ring cross section, thereby make seal ring in groove, be quick condition, rely on the effect of oil pressure to seal ring front and bottom surface, the sealability of seal ring is improved, use the longevity name to prolong.In use there is a shortcoming in this floating type pressure compensation seal arrangement, be exactly when static (no oil pressure), because seal ring can be axially movable in groove, make hydraulic oil can pass through the rear wall seepage of groove, this seepage is little to the piston seal influence, but the rod seal that is used for cylinder ends will cause hydraulic oil seepage outside cylinder, causes the evaporating, emitting, dripping or leaking of liquid or gas phenomenon.

The purpose of this utility model is improved at above-mentioned the deficiencies in the prior art, keeps pressure compensation when a kind of work is provided, cylinder pressure compensation sealing device that again can leakage of oil when static.

The cylinder pressure compensation sealing device that the utility model provides, its seal ring is to be respectively O shape and L shaped two-part seal by the cross section to fuse and constitute, its middle section is that the part of O shape is adjacent to mutually with hydraulic cylinder sealing face (casing wall or piston rod surface), and the cross section is that L shaped part is adjacent to mutually with the whole bottom land and the rear wall of seal groove respectively.

The hydraulic cylinder sealing device that the utility model provides, the part that its seal ring cross section is an O shape has kept the pressure compensation sealability of above-mentioned prior art, and its cross section is L shaped part not only plays further enhanced leaktightness performance when work effect, especially when static state, can guarantee seal ring inaction in seal groove, play the static sealing effect, thereby stop the static leak fuel phenomenon.

Accompanying drawing provides two embodiments of the present utility model.

Fig. 1 is used for the structure of piston seal and cut-away view is installed for embodiment 1-the utility model;

Fig. 2 is used for the structure of rod seal and cut-away view is installed for embodiment 2-the utility model.

With reference to Fig. 1, when the utility model is used for piston seal, seal groove 2 is opened at the two ends of piston 1, and the seal groove outside has ring shaped oil passage 3, the seal ring of installing in the seal groove, its cross section is that the external diameter of part 4 of O type is greater than oil cylinder 8 internal diameters, thereby make it be close to oil cylinder inner wall, the cross section be L shaped part 6 internal diameters less than seal groove at the bottom of the footpath, bottom width is consistent with seal groove bottom land width, thereby guarantee that it is close to bottom land, the two is by thickness and fuse less than the attachment portion 5 of O shape circle radius highly respectively.During work, hydraulic oil enters seal groove by oil duct, pressure is passed to the surface that seal groove contacts with oil, oil pressure is high more, it is tight more that seal ring and workpiece paste, and sealing effect is good more, even the seal ring cross section is the wearing and tearing to some extent within the specific limits of O shape part, the depended on pressure compensation still can keep the better seal performance, plays the effect of pressure compensation sealing; And when static state, the L shaped part of seal ring still tightly recline seal groove bottom surface and rear wall make seal ring stiff in groove, and hydraulic oil just can not be ganged up mutually by piston, reaches static oil-proof purpose.7 is guidance tape among the figure, and 9 is piston rod.

With reference to Fig. 2, when the utility model is used for rod seal, seal groove 13 is opened in bar envelope body 15 inboards that are positioned at oil cylinder 16 ends, by ring shaped oil passage 12 it is communicated with oil cylinder, the seal ring cross section is the external diameters of part 11 internal diameters of O shape less than piston rod 10, the cross section be L shaped part 14 external diameters greater than seal groove at the bottom of the footpath, bottom width is consistent with the seal groove bottom width, the two is by thickness and fuse less than the attachment portion 18 of 0 shape circle radius highly respectively, its pressure compensation sealing principle is identical with embodiment 1, and oil cylinder is oil-proof in the time of can guaranteeing static state.17 is guidance tape among the figure.

Claims

1, a kind of cylinder pressure compensation sealing device, have the seal groove (2) of oil duct (3) and place the seal ring of sealing groove to form by the end, it is characterized in that: said seal ring is respectively O shape and the L shaped two-part seal institute that fuses by the cross section and constitutes, its middle section is that the part (4) of O shape is adjacent to mutually with the hydraulic cylinder sealing face, and the cross section is that L shaped part (6) is adjacent to mutually with the whole bottom land and the rear wall of seal groove respectively.