SU1751553A1 - Piston group of hydrostatic machine - Google Patents

Abstract

The use of mechanical engineering, in particular, volumetric hydraulic machines. The essence of the invention is that the annular elements 2, 3 and 4 of the composite cylinder liner are pressed into the body 1. The elements 2 and 3 have a thin-walled sealing part 5 (6) and a cylindrical guide part. 5 or 6 with a cylindrical surface 7 or 8 is made through the groove. Elements 3 and 4 have annular recesses 10 and 11 for accommodating sealing parts 5 and 6 mounted on the piston 12 with a tension of 2 to 3 pf fy 3 silt

Description

FIG. 2

The invention relates to parts for devices for injecting fluids and volumetric hydraulic actuators, namely, parts of cylinder-piston groups of such devices.

The purpose of the invention is to increase the tightness and reduce the size of the piston group.

This goal is achieved by the fact that the composite cylinder liner of the piston group of a volumetric hydraulic machine is made with a number of design features:

liner guide and carrier functions, as well as lip seal functions, are performed by monolithic annular parts (elements) that combine in their design a metal tapered inside of the cuff and the guide part is a cylindrical sleeve;

the mating of the cylindrical bearing surface (inner surface of the guide part) of said annular elements with the inner conical surface of their lip seal (sealing part) is made smooth by eliminating the stress concentration of the ring groove;

such annular elements are assembled by pressing into the casing so that each previous annular element with its sealing part overlaps with the subsequent annular element in its guide section;

On the inner surfaces of the guiding parts of the annular elements of the composite cylinder liner there are annular recesses, in their shape and volume corresponding to their own sealing part.

The combination of the carrier and guide parts of the cylinder liner in the construction of a single monolithic ring element minimizes the length of the incapable of carrying the directional functions of the seal. This technical solution allows, within the same total length of the cylinder liner, to assemble a package of seals consisting of a large number of elementary devices (sealing parts) and, consequently, to increase the tightness of the cylinder-piston group. The carrying capacity of the composite cylinder liner remains very high, since the cylindrical guide portion of the liner remains between each sealing part. The sealing parts (cuffs) of the proposed design, which will be combined into one design with the guide parts (sleeves), are also able to take on a certain proportion of the guiding functions.

Fig 1 shows a composite cylinder liner, axial section; Fig. 2 shows the cylindrical piston group axial section; Fig. 3 shows a fragment of the axial section of the annular element of the composite cylinder liner at the interface of its internal cylindrical and conical surfaces.

Example. The piston group of a volumetric hydraulic machine is (figs. 1, 2 and 3) body 1, inside a cylindrical bore. The stems of which are pressed into rows of annular elements 2, 3, and 4 of a composite cylinder liner. There may be several annular elements with part profile 3 (depending on the size of the working pressure for which the device is designed). The annular elements 2 and 3 have a complex shape of the radial section of their walls. Each of them has a thin-walled sealing part (cuff) 5 or 6 and a supporting cylindrical part 7 or 8 located below (Coupling) the conical inner surface of the sealing part 5 or 6 with the cylindrical surface 7 or 8 of the supporting part of the ring elements 2 or 3 is made through a curved groove 9 (FIG. 3). In the bearing section 7 of the part 3, as well as in the lower part of the part 4, there are bores (annular grooves) 10 and 11, respectively, sufficient in volume to accommodate the sealing parts 5 and 6 of the elements 2 and 3 in them. The minimum internal diameter d of the sealing hour gay 5 and b elements 2 and 3 are less than the diameter D of the bearing parts 7 and 8 of these elements, and therefore less than the diameter of the piston 12 itself. This design feature provides the necessary tension in the fit of the piston 12 inside the sealing part 5 or 6 of the ring elements 2 or 3 composite cylinder liner.

In the process of moving the piston 12 inside the cylinder liner, it always remains covered by the cuffs 5 and 6. The cylindrical parts 7 and 8 of the elements 2 and 3, as well as the cylindrical part of the element 4, perform the bearing functions. Since the cuffs 5 and b are made metal as one piece cylindrical guides 7 and 8 of elements 2 and 3. they are also able to partially carry guiding functions for the piston 12. In addition, this sealing design does not require special fastenings for it and therefore takes less space

All this allows minimizing the total length of the supporting sections of the composite cylinder liner and maximizing if necessary.

the number of elemental seals 5 and 6. In the end, this allows increasing the tightness of the cylinder-piston group, without resorting to an increase in its length. The compactness of the construction is facilitated by the technical solution provided for the assembly of separate ring elements 2, 3 and 4 overlapped with each other. Coupling the inner conical surface of the cuffs 5 and 6 with the cylindrical surface of the guide parts 7 and 8 of the elements 2 and 3 by means of an annular smooth-junction groove 9 makes it possible to significantly reduce stress concentrations that occur during deformation of the cuffs 5 and 6,

Claims (2)

The economic efficiency of the piston group is due to the possibility of raising the working pressure in the systems of hydraulic actuators and, consequently, to carry out a more substantial energy transfer with fixed sizes of parts of the cylinder-piston group, and therefore with a fixed metal intensity. Claims 1. A piston group of a volumetric hydraulic machine comprising a piston, a cylinder and annular elements mounted between them with conical sealing parts and face supporting platforms, in order to increase tightness and reduce dimensions, annular elements they are provided with cylindrical guide parts, the inner surfaces of which are smoothly mated with the conical surfaces of their sealing parts and are successively placed in the cylinder with the formation of the sleeve. 2. A group according to claim 1. characterized in that annular grooves are smoothly mated with cylindrical and conical surfaces on the inner surfaces of the annular elements in the interface area of their conical and cylindrical parts. 3 group according to claim 1. characterized in that annular recesses are made on the inner surfaces of the cylindrical guide parts of the annular elements, and the annular elements are installed with the possibility of placing the conical part of each next element in the recess of the previous piston / FIG. one FIG. 3