SU1742509A1 - Axial-piston hydraulic machine - Google Patents

Abstract

Usage: hydraulic machines with an inclined cylinder block, the flange of the drive shaft which has a hydrostatic discharge. The essence of the invention: the hydrostatic unloading of the shaft flange is carried out by performing a series of axial and radial chambers in which the discharge pistons are located. The chambers communicate with the working chambers of the hydraulic machine through the channels of hydrostatic discharge. Axial discharge pistons in axial chambers are installed offset from the respective hydrostatic channels. unloadings made in the flanges. The offset angle and the diameter of the arrangement of the axes of the discharge pistons are related by dependencies 0a arctg (jtgy), Da D-sec0a, where & a is the angle of displacement of the axial pistons; Da is the diameter of the axis of the axial relief pistons; a is the distance between the axis of the radial pistons and the plane passing through the centers of the spheres in the shaft flange; I is the distance from the central axis of the shaft to the point of application of force to the shaft flange; y - the angle of the cylinder block; D is the diameter formed by the centers of the heads of the connecting rods located in the flange of the shaft. The diameter (of the radial discharge pistons of the hydrostatic and static bearings is related to the diameter of the working pistons by the following relationship (D / 2i) -siny. Where dr. is the diameter of the radial discharge pistons of the hydrostatic supports; dn is the diameter of the working pistons. 1 Cp. ly, 3 il. (L S

Description

The invention relates to hydraulic engineering, in particular to axial-piston hydraulic machines.

A known axial-piston hydraulic machine structure comprising a shaft with a flange mounted in a housing on rolling bearings, connecting rods pivotally connected to axial pistons located in the shaft flange openings and forming a static washer with a hydrostatic support, a unit of radial unloading of the bearing unit, acting

on the outer surface of the shaft flange and containing a piston in communication with the discharge line of the hydraulic machine.

The disadvantage of this design is the necessity of supplying the working fluid pressure to the radial unloading unit from the outside, which is connected with external pipelines and considerable body complexity and leads to an increase in size, decrease in processability and reliability. In addition, the presence of only one piston in the radial discharge unit causes it

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significant dimensions or concentration of the load at the place of its contact with the shaft flange.

Also known is the design of a hydraulic machine, comprising a shaft with a flange mounted on rolling bearings mounted in a sleeve, axial located in a sleeve and radial located in a housing, pistons in contact with a shaft flange and forming hydrostatic bearings with it.

A disadvantage of the known hydraulic machine is also the need for external lines for supplying injection pressure to the pistons of the hydrostatic bearings and the associated desire of the structure.

The closest to the technical essence of the invention is an axial-piston hydraulic machine comprising an inclined cylinder block and a drive shaft with a flange having hydrostatic bearings, which are made in the form of a series of axial relief pistons installed in axial chambers and communicating with working chambers formed by a piston In the cylinders, in addition, in the flange there are a number of radial chambers of hydrostatic unloading, the inlet and outlet channels to the chambers have an angular displacement relative to the corresponding holes, also communicate with the working chambers cylinder.

A disadvantage of a hdromera is the implementation of hydrostatic bearings in the form of radial chambers made on the cylindrical surface of the shaft flange and in contact with the hydraulic machine housing, resulting in increased wear and leakage of the working fluid and reduced reliability when the contact surfaces are worn.

The aim of the invention is to improve the reliability of hydraulic machines.

This goal is achieved by the fact that the radial chambers of hydrostatic unloading are equipped with unloading pistons, and the axial discharging pistons are set offset relative to the corresponding hydrostatic unloading channels made in the flange, the angle of displacement and the diameter of the axes of the unloading pistons being associated with the following relationship:

ft arctg (| tgx),

Da D-SeC & where & and the angle of displacement of the axial pistons;

Da is the diameter of the axis of the axial relief pistons;

a is the distance between the plane of the axes of the radial pistons and

a plane passing through the centers of the spheres in the flange of the shaft;

I is the distance from the central axis of the shaft to the point where force is applied to the shaft flange; y- angle of the cylinder block;

D is the diameter formed by the centers of the heads of the connecting rods located in the flange of the shaft.

Figure 1 shows the axial piston hydraulic machine, a longitudinal section;

figure 2 is a view from the side of the flange and from the side of the drive end of the shaft.

The design includes a housing 1, a drive shaft 2 with a flange 3, in which rods 4 workers are hinged

hydraulic machine pistons moving in the bores of the cylinder block 5. The drive shaft 2 is installed in the housing 1 by means of rolling bearings 6. The flange 3 forms the case of a block of hydrostatic bearings having

a series of axial 7 and a series of radial 8 pistons.

The connecting rods 4 and the flange 3 are provided with channels 9-11, which hydraulically connect the working cavities 12.13 of the pistons 7, 8 to the high and low pressure lines of the hydraulic machine.

When this axis of the pistons 7, 8 are made with an angular displacement relative to their corresponding holes 14 in the flange 3 and form with the housing 1 and the holder 15 axial and radial hydrostatic bearings, respectively,

During the operation of the hydraulic machine, the forces from the side of the cylinder block 5 through the connecting rods 4 are transferred to the rolling bearings 6 in the form of external axial and radial

loads, causing their reactions.

When connecting cavities 12, 13 through channels 9-11 to the working chambers of the hydraulic machine in hydrostatic bearings formed by rows of pistons 7 and 8,

respectively, the resulting axial and resulting radial force, which unloads the rolling bearings 6, is created. A radial force due to an angular displacement of 90 ° is applied to the flange 3 of the shaft.

vertically and compensates for the external radial load. The axial resulting force compensates for the external axial load, with the angle of displacement 6a and the diameter Da of the axial unloading axes

The pistons are related to the geometrical parameters of the hydraulic machine by the following relationship:

a arctg (f-tgx);

Da D -Sec6 a.

where va is the angle of displacement of the axial pistons;

Da is the diameter of the axes of the axial relief pistons;

a is the distance between the axis of the radial pistons and the plane passing through the centers of the spheres in the shaft flange;

I is the distance from the central axis of the shaft to the point of application of force to the shaft flange;

y is the angle of the cylinder block;

D is the diameter formed by the centers of the heads of the connecting rods located in the flange of the shaft.

The eccentricity in the axial piston hydraulic machine is determined by the sin-,

where z is the number of connecting rods.

In order to fully compensate for the external radial force, the diameter of the radial discharge pistons of the hydrostatic bearing block should be related to the diameter of the working pistons of the hydraulic machine according to

 ,,

where dr is the diameter of the radial discharge pistons of hydrostatic bearings;

dn is the diameter of the working pistons;

D is the diameter formed by the centers of the heads of the connecting rods located in the flange of the shaft;

I is the distance from the central axis of the shaft to the point of application of force to the shaft flange;

y - the angle of the cylinder block.

The definition is based on the indicated dependencies of va, Da. dr provide full compensation for rolling bearing loads (the entire load is perceived by hydrostatic bearings), eliminates the need for using power rolling bearings, significantly reduces the effect of wear in hydrostatic bearings on the performance of the hydraulic machine and increases its reliability.

Claims (2)

1. Axial-piston hydraulic machine, containing installed in the housing on bearings drive shaft with flange, cylinder block with working pistons, the connecting rods of which are articulated in the flange of the shaft, having hydrostatic supports in the form of a series of axial discharge pistons, hydraulically communicated with the working chambers, and a series of radial chambers of hydrostatic discharge, the supply channels to which have an angular displacement relative to their corresponding holes, which is different in that. in order to increase reliability, the hydrostatic discharge radial chambers are equipped with discharge pistons, while axial the discharge pistons are mounted offset from the respective hydrostatic discharge channels made in the flange, the angle of displacement and the diameter of the axes the discharge pistons are related as follows: 25 0a arctg (ftgx): Da D-sec, where va is the angle of displacement of the axial pistons; Da is the diameter of the axis of the axial discharge pistons; a is the distance between the axis of the radial pistons and the plane passing through the centers of the spheres in the shaft flange; I is the distance from the central axis of the shaft to the point of application of force to the shaft flange; y is the angle of the cylinder block; D is the diameter formed by the centers of the heads of the connecting rods located in the flange of the shaft. 2. Hydromachine pop.1. This is due to the fact that the diameter of the radial discharge pistons of the hydrostatic bearings is related to the diameter of the working pistons by the following relationship: dr dnV§slny where dr is the diameter of the radial discharge pistons of hydrostatic support; dn is the diameter of the working pistons. 6 t Ј & & t t g 60S2W. I