RU2327629C1 - Combined dual-action telescopic hydraulic cylinder - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: hydraulic cylinder includes a coaxial set of piston steps with external and internal cases. One of the steps contains the two-side rod combined with the internal case with its ends having various external diameters, and the piston with various working areas of its sides. Identical cavities of steps are hydraulically connected in pairs forming the combined cavities. Piston cavities are arranged so that to allow arrival to opposite phases corresponding to maximum and minimum their volumes in extreme positions of the hydraulic cylinder. The external case is made executed with one end face bottom accommodating a rigidly fixed end of the two-side rod of a smaller diameter. The piston is made in the form of a sleeve with cylindrical necks and collar and arranged so that to allow enveloping of the two-side rod to form the cavity limited by cylindrical necks. Cylindrical necks and collar are made to interact and to contact with the two-side rod and the external case, respectively, the said contact being sealed. The length of the piston should not be less than the travel of this step of the hydraulic cylinder.

EFFECT: higher efficiency and reliability.

2 cl, 3 dwg

Description

The invention relates to hydraulic mechanisms of a telescopic type, namely to volumetric power hydraulic motors with rectilinear reciprocating movement of double-acting, and can be used in shipbuilding, engineering and other industries.

Known double-acting telescopic hydraulic cylinders (GC) with single-sided rods for implementing large strokes in conditions of insufficient space, which is small to accommodate a conventional translational hydraulic motor (DG), the stroke of which is limited by the length of the assembled cylinder and in these conditions is always less than the length of the required stroke. / Bashta T.M. Volumetric pumps and hydraulic motors of hydraulic systems. M .: Mechanical Engineering, 1974, p. 516-518, Fig. 216 /. Such multi-cylinder hydraulic cylinders comprise a large cylinder in which a large diameter piston is located with a rod having an internal cavity in which a smaller diameter piston with its rod is placed. The large cylinder, pistons and rods are concentric and have the possibility of relative and sequential movement, and the sum of their moves is equal to the total stroke of the output link. The supply (withdrawal) of the working fluid is simultaneously carried out both to the movable and to the stationary elements, namely to the common piston cavity and individual rod cavities. The disadvantages of the known telescopic hydraulic cylinders are the need to use flexible pipelines that ensure the passage of the working medium to the moving parts of the hydraulic cylinders, as well as the lack of functionality, which is due to the lack of support, except for sequential, also independent action of the stages of the HZ.

Known telescopic HZ double-acting with one-sided rods, providing simultaneous extension of all stages / Podgorny Yu.P. Hydraulic drives for ground handling aircraft. M .: Transport, 1980, p. 63.65, fig. 4.8 /. The hydraulic cylinder consists of a housing and three cylinders, which form three direct pressure chambers and three backpressure chambers, while the counterpressure chamber of the cylinder of the previous stage and the direct pressure chamber of the cylinder of the next stage are paired with the formation of a closed joint cavity, which have two cylinders. The liquid from the pump in the forward stroke is fed into the direct pressure chamber of the housing. To fill the hydraulic cylinder with liquid, check valves mounted in the piston heads (except for the piston rod) are used. From the backpressure chamber of the rod, liquid is discharged through the rod.

For the reverse stroke, the fluid is supplied through the rod to the stem counter-pressure chamber, and from the direct pressure chamber formed by the housing, the working fluid is drained into the oil tank.

With forward and reverse strokes, simultaneous extension (removal) of all stages of the hydraulic cylinder occurs.

The disadvantages of the known telescopic double-acting hydraulic cylinder with the simultaneous extension of all stages is the need to use flexible pipelines that ensure the passage of the working medium to the moving part of the hydraulic cylinder, as well as the lack of functionality, which is caused by the impossibility of providing, in addition to the simultaneous, also independent action of the stages of the HZ.

Known telescopic hydraulic cylinders of double-sided force with single-sided rods containing several concentrically arranged pistons (with rods) moving one relative to the other, while the stroke of the output link is equal to the sum of the strokes of each / Marutov V.A., Pavlovsky S.A. Hydraulic cylinders. M .: Engineering, 1966, p. 8, fig. 3, p. 97, 99, fig. 86a /. Both in the piston and in the rod cavity, the fluid is supplied through the rod. Both in the extended and retracted positions of the pistons, the piston cavity is a single (combined) cavity of the hydraulic cylinder. In the retracted position of the pistons, all the rod cavities are interconnected and form a separate joint cavity, and in the extended position of the pistons the rod cavities are connected to the combined piston cavity, except for the rod cavity of the rod through which the working fluid is supplied (withdrawn). Thus, the rod cavities in the process of relative movements of the moving parts alternately sequentially switch from one united cavity to another. When fluid is supplied to the piston cavity, the pistons successively extend, starting from a large diameter piston to a smaller diameter piston. When fluid is supplied to the rod cavity, the piston of the smallest diameter is first drawn in, and then the “telescope” is successively folded in the reverse order - from the piston of the smallest diameter to the largest.

If it is impossible to supply the working fluid to any of the combined cavities through the stem, it is necessary to use flexible pipelines that ensure the passage of the working fluid to the moving parts of the HZ.

The well-known double-acting telescopic hydraulic cylinders provide sequential movement of the pistons, however, the independent action of the steps cannot be realized, which can be considered a drawback of the device in terms of design optimization and expansion of functionality.

Known double-acting telescopic hydraulic cylinders (TCCC), containing a coaxial set of piston stages with cylindrical bodies and rod cavities at each stage. Such TGCD contains a step in the form of a two-sided rod combined with one of the bodies with ends of different external diameters and a piston in contact with the external housing, the working areas of the sides of which are not the same. Unlike cavities of the hydraulic cylinder stages are pairwise hydraulically connected to form joint cavities. Piston cavities of each stage of TGCD are installed with the possibility of their arrival in opposite phases, which correspond to the maximum and minimum values of their volumes, in the extreme positions of the hydraulic cylinder. Known TGCD in one of the options are implemented with a minimum total length of telescopic links in the fully extended position of the hydraulic cylinder, due to insufficient space, the length of which is limited by a cylinder with only one internal stage extended, which under these conditions provides the necessary total stroke caused by the output link, equal to the sum of the moves of each of the links - steps / RF patent No. 2153464, prior. 08/30/1999, publ. 07.27.2000 /.

When supplying (draining) the working fluid to pairwise hydraulically connected opposite cavities of the TGCD stages, forming the combined cavities, and alternately connecting to the pressure of all its cavities, sequential and independent movement of the TGCD stages is carried out due to the differential principle of the interaction of the moving links.

A disadvantage of the known TTCD with a minimum total length of telescopic links in the fully extended position of the hydraulic cylinder is that in the initial (retracted) position, at least one of its landing (high-precision) surfaces is open and not protected from external influences. From the above it follows that if in the initial (retracted) position of the telescopic hydraulic cylinder at least one of the landing (high-precision) surfaces is open and not protected from external influences, then in conditions of prolonged exposure to sea water (aggressive environment) and the absence of the possibility of maintenance as well as in the absence of cranking for a long time, corrosion products, salinization, fouling, etc. / V. Pludek are collected on an open outer surface. Corrosion protection at the design stage. M .: Mir, 1980, p. 50; C. Brebbia, S. Walker. The dynamics of offshore structures. L .: Shipbuilding, 1983, p.150 /, which, when the corresponding movable link of the hydraulic cylinder moves, will affect its seals due to abrasive action, which significantly reduces the reliability of the hydraulic cylinder when working in sea water.

Known telescopic double-acting hydraulic cylinder according to US Pat. No. 2153464 is selected as the closest analogue.

The objective of the invention is to increase the efficiency of use and increase the reliability of the hydraulic cylinder by providing in its original (retracted) position the protection of all movable joints from the effects of the external environment while minimizing, under conditions of a given stroke, the total length of telescopic links in the fully extended position of the hydraulic cylinder.

The problem is solved in that in a combined TCC, including a coaxial set of piston stages with external and internal cylindrical bodies, in which one of the stages contains a two-sided rod combined with the internal body, the ends of which have different outer diameters, and has a piston in contact with the external body, working the areas of the sides of which are different, as well as including the hydraulically connected in pairs with the formation of the joint cavities opposite cavities of the mentioned steps, the piston cavities of which installed with the possibility of their arrival in opposite phases, corresponding to the maximum and minimum values of their volumes in the extreme positions of the hydraulic cylinder, in accordance with the invention, the outer casing is made with one end bottom on which the end of a two-sided rod of a smaller diameter is rigidly fixed, and the piston is made elongated, in the form sleeves with cylindrical necks and a shoulder with the possibility of covering it with a double-sided rod with the formation of a cavity bounded by cylindrical necks, while cylindrical necks and a shoulder in ensuring full engagement and sealing engagement with double rod and the outer housing, respectively, and the length of the piston - at least the stroke cylinder of the stage.

In addition, the extent of the area of the tight contact of the shoulder on the outer surface of the elongated piston is less than the stroke of this stage of the hydraulic cylinder.

The technical result of the invention is to increase the efficiency of use and increase the reliability of the hydraulic cylinder by ensuring in its original (retracted) position that all movable joints are protected from environmental influences while minimizing, under conditions of a given stroke, the total length of telescopic links in the fully extended position of the hydraulic cylinder, as well as ensuring consistent and independent actions of the hydraulic cylinder stages.

The invention is illustrated by drawings, in which:

figure 1 presents a General view of a combined telescopic double-acting hydraulic cylinder in the retracted (initial) position;

figure 2 - the same, in the fully extended position of the HZ;

figure 3 is the same in the intermediate fixed position of the HZ.

The combined telescopic double-acting hydraulic cylinder (Figs. 1, 2, 3) contains a telescopic set of piston stages, which includes an internal cylindrical housing 1 of a small stage, an external cylindrical housing 2 of a large stage, a piston rod 3 of a small stage with channels 4, 5 for supply and drainage of the working fluid, an elongated piston 6 of a large stage, a cylindrical body 1 of a small stage combined with a two-sided rod of a large stage. The latter has cylindrical ends, respectively, 7 - a larger outer diameter and 8 - a smaller outer diameter. The piston 6 is slidable on the outer surface of the two-sided rod, combined with the inner cylindrical body 1 of the small stage and on the inner surface of the outer body 2. The telescopic set of stages is made so that it forms a small rod 9 and a large piston 10 cavity of a small stage, small 11 and a large 12 cavity of a large stage, while the cavity 9 is in communication with the cavity 12 through the channels 13, 14, 15, and the cavity 10 is in communication with the cavity 11 through the channel 16 with the formation of the combined cavities. The small cavity 11 of the large stage for the functional purpose corresponds to the rod cavity of this stage, and the large cavity 12 of the large stage for the functional purpose corresponds to the piston cavity of the same stage. Piston cavities of the hydraulic cylinder include piston cavities of each stage, respectively, a large piston cavity 10 of a small stage and a large cavity 12 of a large stage. The outer cylindrical body 2 of the large stage is made in the form of a glass with one end bottom 17, on which the end 8 of the small diameter of the two-sided rod of the large stage is rigidly fixed with fasteners 18, while its other end 7, of a larger diameter, is located outside the body 2. The piston 6 of the large stage is made with the coverage of the double-sided rod, in particular its ends 7 and 8. The piston 6 of the large stage is made with unequal working (effective) areas so that the working area of the piston from the side of the large cavity 12 exceeds the working area the piston groove from the side of the small cavity 11, while, as noted above, the outer diameter of the lower end 7 of the double-sided rod exceeds the external diameter of its upper end 8. The piston 6 forms a cavity 11 with the double-sided rod of a large stage, bounded by cylindrical necks 19 and 20, interacting with cylindrical surfaces of the ends 7 and 8 of the double-sided rod. The cylindrical neck 19 is paired with the cylindrical upper part 8 of the double-sided rod, and the cylindrical neck 20 is paired with the cylindrical lower part 7 of the double-sided rod. The necks 19 and 20 have different diameters in accordance with the diameters of the ends of the stem. A flange 21 is also made on the piston 6, coupled to the inner surface 22 of the outer casing 2. The piston 6 is elongated, not less than the stroke of a large stage of the hydraulic cylinder, allowing tight contact with the outer cylindrical surfaces of the ends 7 and 8 of the double-sided rod and with the inner surface 22 of the outer casing 2.

The extent of the area of tight contact on the outer surface of the elongated piston 6 is less than the stroke of this stage of the hydraulic cylinder. Otherwise, this area will be exposed to the external environment, which may adversely affect the operational reliability of the gas center. The piston 6 of the large stage is made in the form of a floating stepped sleeve conjugated by means of cylindrical necks 19 and 20 with rod ends of different diameters 7, 8, and by means of a shoulder 21, with a cylindrical surface 22 of the outer casing 2.

The hydraulic cylinder for creating a tight contact is equipped with seals 23, 24, 25, 26, 27, 28. A flange 29 is made on the piston 6, which provides the connection of elements of other mechanisms.

The length of a large stage of the hydraulic cylinder is not less than twice the stroke of this stage. In the fully extended position of the hydraulic cylinder (Fig. 2), its length is minimal and limited by the housing with only one small step extended, which under these conditions provides the necessary total stroke size due to the stroke of the output link, equal to the sum of the moves of each of the links - steps.

The combined telescopic double-acting hydraulic cylinder is installed in such a way that in the initial position (Fig. 1) the volume of the large cavity 10 of the small stage is minimal, and the volume of the large cavity 12 of the large stage is maximum, therefore, the extreme positions of both stages are opposite in phase, while the opposite cavity of the hydraulic cylinder pairwise hydraulically connected with the formation of the joint cavities.

In the initial position (figure 1), all landing surfaces that provide tightness are structurally closed and protected from any external influences.

It is essential for the claimed double-acting telescopic hydraulic cylinder to be attached to a fixed element, which can be carried out either by a piston rod 3 of a small stage, or by a cylindrical body 1 of a small stage combined with a two-sided rod of a large stage, or by a cylindrical outer case 2 of a large stage, either by the piston 6.

In cases of attachment to a fixed element (foundation) for the piston rod 3 or for the piston 6 in the extreme positions of the combined telescopic double-acting hydraulic cylinder, the resulting movement of its stages is determined by summing the movements of the moving links of these stages of the cylinder head, and in the case of attachment to a cylindrical outer casing 2, rigidly connected with the end of the two-sided rod, combined with the cylindrical body 1 or behind the body 1, this possibility is excluded.

Combined telescopic double-acting hydraulic cylinder works as follows.

The working fluid under pressure is fed through the channel 4 into the cavity 10 and through the channel 16 into the cavity 11, and the cavity 12 through the channels 13, 15, 14 together with the cavity 9 is connected to the drain channel 5 (figure 1). Under fluid pressure, the housing 1 and the piston 6 from the initial (retracted) position are sequentially forced upward, while the piston 6 moves into the housing 2. The hydraulic cylinder is installed in the extreme extended position, at which the volume of the large cavity 10 is maximum - the combined cavity 10 is connected to the pressure , 11, and the other combined cavity 9, 12 is connected to the drain and the volume of the large cavity 12 is minimal, i.e. extreme positions of both steps are opposite in phase (figure 2).

The working fluid under pressure is supplied through channels 4 and 5 in the cavity 9 and 10, as well as in the cavity 12 and 11 due to the corresponding hydraulic connections-channels 14, 15, 13 and 16 (Figs. 1, 2). Under fluid pressure, the hydraulic cylinder is installed in an intermediate fixed position, in which only the housing 1 is extended, the volumes of large cavities 10 and 12 are maximum, the combined cavities are connected with the pressure, i.e. the extreme positions of both steps are single-phase (Fig. 3).

The movement of the movable elements occurs due to the fact that the working area of the piston rod 3 from the cavity 10 exceeds the working area from the cavity 9, and the working area of the piston 6 from the cavity 12 exceeds the working area from the cavity 11, i.e. carried out due to the differential principle of the interaction of the moving links.

The working fluid under pressure is fed through the channel 5 into the cavity 9 and through the channels 14, 15, 13 into the cavity 12, and the cavity 11 through the channel 16 together with the cavity 10 is connected to the drain channel 4 (Fig.2, 3).

Under the pressure of the liquid, the hydraulic cylinder is set to its original (retracted) position, in which the housing 1 and piston 6 are removed (relative to the fixed element - foundation), the volume of the large cavity 12 is maximum - the combined cavity 9, 12 is connected to the pressure, and the other combined cavity 10, 11 connected to the drain and the volume of the large cavity 10 is minimal, i.e. extreme positions of both steps are opposite in phase (Fig. 1).

For the passive return (lowering) of the HC to its original position, it is sufficient to report the combined cavities 9, 12 and 10, 11 with a drain through channels 4, 5 (Figs. 2, 3), while the HC passes into the retracted position under the influence of an external load, for example, mass lifted load.

The inventive combined telescopic hydraulic cylinder allows to increase the efficiency of its use, as well as to increase its operational reliability by providing in its original (retracted) position the protection of all movable joints from environmental influences while minimizing the total length of the telescopic links in the fully extended position of the hydraulic cylinder under conditions of a given stroke as well as ensuring consistent and independent action of the stages of the hydraulic cylinder.

Claims (2)

1. A combined telescopic double-acting hydraulic cylinder, comprising a coaxial set of piston stages with an external and internal housing, with one of the stages containing a two-sided rod combined with the internal housing, the ends of which have different external diameters, and a piston whose working areas of the sides are different, and with opposite cavities of the mentioned steps, connected hydraulically in pairs with the formation of combined cavities, and with piston cavities that are installed with the possibility of their approach to opposite phases, corresponding to the maximum and minimum values of their volumes in the extreme positions of the hydraulic cylinder, characterized in that the outer casing is made with one end bottom on which the end of a two-sided rod of smaller diameter is rigidly fixed, and the piston is made in the form of a sleeve with cylindrical necks and a shoulder and installed with the possibility of covering the bilateral rod with the formation of a cavity bounded by cylindrical necks, while the cylindrical necks and flange are made to ensure interaction and ermetichnogo contact with double rod and the outer housing, respectively, and the length of the piston is made not less than the stroke of the hydraulic cylinder stages. 2. The combined telescopic hydraulic cylinder according to claim 1, characterized in that the extent of the area of the sealed contact of the piston flange with the outer casing is less than the stroke value of this stage of the hydraulic cylinder.

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