RU2594098C1 - Plunger hydraulic cylinder - Google Patents

Abstract

FIELD: energy.

SUBSTANCE: hydraulic cylinder is intended for use in power engineering, metallurgy, construction and mining industries. Hydraulic cylinder comprises piston, cylinder, where on working cylindrical surface of piston, made from structural steel, there are circular rollers with width 6-12 mm made from high-hardness wear-resistant friction martensite, spaced apart through a distance larger than width of rollers by 1.2-1.5 times, having in cross section, in middle part, support cylindrical surfaces and inclined sides, arranged on both sides of support surfaces. Exit of piston from cylinder is performed through a cover, in which there is a drain hole and a cup-type seal, on other side hydraulic cylinder adjoins a body, having two inlet branch pipes with diameter equal to half diameter of hydraulic cylinder, hydraulic cylinder working surface is tempered with HFC.

EFFECT: technical result is longer service life of piston of hydraulic cylinder, enabling operation thereof at speeds higher than 2÷3 m/s, reduced friction losses.

1 cl, 3 dwg

Description

The invention relates to the field of mechanical engineering and can be used in energy, metallurgy, construction, mining industries to increase the service life of the plunger cylinder, which is part of machines and mechanisms with hydraulic drive.

Known plunger hydraulic cylinder [1, p. 36-37, 47-48; 2, p. 72-73, 82] used in drives of various machines. Such a hydraulic cylinder consists of a housing in which a rod (plunger) is located. At the outlet of the plunger from the cylinder there are seals, which sometimes act as a guide sleeve [2, p. 82].

The marked type of hydraulic cylinder has a short service life due to the rapid wear of the seals and guide bushings. The wear products during operation are not removed from the cylinder and play the role of an abrasive that intensively wears the plunger and the parts in contact with it, in addition, this position significantly increases friction losses. The short length of the guide bushings does not allow the hydraulic cylinder to absorb radial loads. For this purpose, support rollers are sometimes installed inside the cylinder [2, p. 82]. This complicates the design of the hydraulic cylinder. It is impossible to control the operation of these videos and their condition.

The closest in technical essence and the achieved result to the invention is a plunger hydraulic cylinder [3] containing a housing (cylinder), a plunger, a guide sleeve, a seal, a compression nut, a wiper. The guide sleeve is made of anti-friction material, such as bronze. The outer surface of the guide sleeve is made in the form of a stepped cylinder with the formation of a collar, which is in contact with the end face of the clamping nut with a made internal bore, in which part of the guide sleeve is placed. Thus, an increase in the length of the guide sleeve by 25-30% was achieved without increasing the axial dimensions of the hydraulic cylinder and its service life was increased.

Reinforcing operations (treatments) for the plunger and guide sleeve in this hydraulic cylinder is not provided. During the reciprocating movement of the plunger, especially in the presence of radial loads, the crude steel plunger and the bronze guide sleeve wear due to friction, forming microparticles that are in the gap between the plunger and the guide sleeve and intensify the wear process. Wear products cannot be removed from the gap, since they are in a “dead end” and the oil does not flush the gap, but only fills it (both during working and during idle plunger).

This hydraulic cylinder cannot work at high speeds of the plunger movement (of the order of 2 ÷ 3 m / s and higher), as it has a small feed-through cross section of the feed hole and large hydraulic losses associated with sharp changes in the diameters of the feed hole and cylinder.

The objective of the invention is to increase the service life of the plunger hydraulic cylinder, making it possible to work with speeds above 2 ÷ 3 m / s, removing wear products from the hydraulic cylinder during its operation and reducing friction losses.

The problem is achieved in that in the plunger hydraulic cylinder, which includes a plunger, a cylinder, on the working cylindrical surface of the plunger made of structural steel, ring rollers are made of a width of 6-12 mm from a high-hardness wear-resistant friction martensite, spaced apart from each other by a distance greater than the width of the rollers is 1.2 ÷ 1.5 times, having in the cross section in the middle part supporting cylindrical surfaces and inclined sides located on both sides of the supporting surfaces, the plunger exits the cylinder core made through the cover in which are formed the drain hole and delivered lip seal, on the other hand adjoins the cylinder body having two inlet pipe diameter equal to half the diameter of the cylinder, the working cylinder surface hardened T.V.CH.

In FIG. 1 is a cross-sectional view of a plunger hydraulic cylinder;

in FIG. 2 is a plan view of the plunger hydraulic cylinder shown in FIG. one;

in FIG. 3 - node A in FIG. one.

The plunger hydraulic cylinder contains a cylinder consisting of a housing 1 having two inlet pipes 2, two working bodies 3 and 4, having on the inner surface hardened T.V.Ch. a layer 5, a cover 6, in which a drain hole 7 is made, a lip seal 8 is installed, and through which the plunger 9 is made from the cylinder, made of structural steel and provided with martensitic ring rollers 10 having bearing surfaces "C" and inclined sides 11. The diameters of the inlet pipes 2 of the housing 1, adjacent to the hydraulic cylinder on the other hand, are equal to half the diameter of the hydraulic cylinder to exclude sharp changes in the diameters of the pipes and the working housing 3.

The plunger hydraulic cylinder operates as follows. The working stroke of the plunger 9 is performed under the action of a liquid (oil) under pressure supplied through the nozzles 2 of the housing 1 to the working housing 3. The plunger 9 is moved to the stop in the limiter mounted outside the hydraulic cylinder (not shown in Fig. 1). The return stroke of the plunger 9 is carried out under the influence of an external load.

Due to the two nozzles 2 of the housing 1 of large cross section, each of which is directly connected to the hydraulic distributor, the absence of sharp differences in the diameters of the nozzles 2 and the working housing 3, the speed of the plunger 9 reaches 6 ÷ 8 m / s, which is necessary to create machines with shock loads, for example, in the promising hydraulic jaw crushers under development [5, p. 46-49]. The angle α in FIG. 1 varies, depending on the layout of the machine, which is driven by a plunger hydraulic cylinder, from 90 ° to 180 °.

The seal of the plunger 9 in the working cylinders 3 and 4 is achieved due to the convex annular rollers 10 (Fig. 1 and 3) of structurally transformed metal of the plunger 9 (friction martensite) [4] with high hardness and wear resistance, which form oil pockets between each other, and with their inclined sides 11 (Fig. 3) create, at speeds of the plunger 9 above 2 ÷ 3 m / s, together with the hardened T.V.Ch. a layer of 5 cylinders 3 and 4, oil wedges and hydrodynamic forces supporting the plunger 9. The rollers are divided into two groups of 3-5 rollers in each.

рабочих цилиндров 3 и 4 (фиг. 3) маслом, составляющим утечки, не превышающие 1-2% от расхода плунжерного гидроцилиндра, во время работы и уносятся через отверстие 7 в бак гидросистемы (после соответствующей очистки). Коэффициент трения между поверхностями из мартенсита трения и закаленными Т.В.Ч. в два раза меньше, чем между двумя стальными деталями при обычной закалке.In cases of a decrease in the speed of movement of the plunger 9 below 2 ÷ 3 m / s, when liquid is not provided, but there is semi-dry friction, contact between the rollers of the plunger 9 and the hardened layer 5 of the working cylinders 3 and 4 occurs along the supporting surfaces "C" (Fig. 3 ) having high wear resistance under these conditions. The width of the rollers h (Fig. 3), depending on the diameter of the hydraulic cylinder D _c (Fig. 3) and its length, is from 6 to 12 mm, which allows the creation of plunger hydraulic cylinders with an optimal supporting surface for working with semi-dry friction. Surfaces “C” are polished. The wear products of the rollers 11 and the layer 5, hardened by T.V.Ch., represent particles of several microns in size, which are washed out from the gap between the diameter D _{o of the} tops of the rollers and the diameter

working cylinders 3 and 4 (Fig. 3) with oil, constituting leaks that do not exceed 1-2% of the flow rate of the plunger hydraulic cylinder, during operation and are carried through hole 7 into the hydraulic tank (after appropriate cleaning). Friction coefficient between friction martensite surfaces and hardened two times less than between two steel parts during normal hardening.

Thus, the object of the invention is achieved.

Literature

1. Sveshnikov V.K., Usov A.A. Machine-driven hydraulic drives: Reference. - 2nd ed., Revised. and add. - M.: Mechanical Engineering, 1988. - 512 p., Ill.

2. Ioffe A.M. et al. Hydraulic equipment of metallurgical plants / A.M. Ioffe, O.N. Kukushkin, F.A. Naumchuk, E.K. Levchuk, V.A. Sergieni. - M.: Metallurgy, 1989 .-- 248 p.

3. RF patent 2406885. Priority 02.16.2009.

4. RF patent 2466002. Priority 06/01/2011.

5. Klushantsev B.V. and others. Crushers. Design, calculation, operation features / B.V. Klushantsev, A.I. Kosarev, Yu.A. Muizemnek. - M.: Mechanical Engineering, 1990. - 320 p., Ill.

Claims (1)

A plunger hydraulic cylinder including a plunger, a cylinder, characterized in that on the working cylindrical surface of the plunger made of structural steel, ring rollers are made of a width of 6 ÷ 12 mm from a highly hard-wearing wear-resistant friction martensite, spaced apart by a distance greater than the width of the rollers of 1.2 ÷ 1.5 times, having in the cross section, in the middle part, supporting cylindrical surfaces and inclined sides located on both sides of the supporting surfaces, the plunger exited the cylinder through the cover, in Torah performed drainer and delivered lip seal, on the other hand adjoins the cylinder body having two inlet pipe diameter equal to half the diameter of the cylinder, the working cylinder surface hardened T.V.CH.

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