SU1513249A1 - Method of accelerated life-time trial of positive displacement hydraulic transmissions - Google Patents

Abstract

The invention relates to engineering hydraulics, and specifically to methods for testing volumetric hydraulic transmissions from axial-piston hydraulic machines. The aim of the invention is to reduce the energy loss during testing. The method of loading is implemented by cyclically varying the pressure of the fluid by briefly connecting high and low pressure lines via an adjustable hydraulic connection. In this case, the loading parameters are determined by the angular velocity of the hydraulic machine shaft and the application of an external load to it. 4 il.

Description

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The invention relates to engineering hydraulics, in particular, to methods for accelerated life testing of volumetric hydraulic transmissions, for example, axial-piston hydraulic machines for hydraulic systems of various machines.

The purpose of the invention is to reduce energy losses during testing.

Figure 1 shows the stand for the accelerated life tests of volumetric hydraulic transmissions in figure 2 — axial-piston hydraulic machine, longitudinal section J in fig. 3 — section A — A in figure 2 in figure 4 — section B — B on FIG. 2

Stand (Fig. 1) for accelerated re-. The test of volumetric hydraulic transmissions contains a tested hydraulic transmission consisting of an adjustable pump 1 and an unregulated hydraulic motor 2, which are connected by hydraulic lines 3 and 4. The drive shaft of the adjustable pump 1 is kinematically connected to the shaft of the bench electric motor 5, and the hydraulic motor shaft 2 - with a balanced DC dynamometer, which is an adjustable impedance 6.

The volumetric hydraulic machine () contains a drive shaft 7, rotating, a cylinder block 8 in contact with the end surface of the attachment bottom 9, in which a channel 10 is made, which connects the working windows 11. The distribution disk 12, fixed relative to the rear cover 13, has distribution windows high 14 and low 15 pressure.

The method is carried out as follows.

An electric motor 5 is turned on, which rotates the drive shaft of the regulated pump 1, which supplies pressurized fluid to the hydraulic motor 2, the load on the shaft of which is created by adjustable resistance 6. At the same time, the cylinder block 8 rotates with the attached bottom 9. Channel 10, connecting or a couple

pairs of working windows 11 in the additional floor

9, is moved relative to the distribution disk 12 to the bridge 16, the connection of the high window 14 and the low 15 pressure. Thus, for one revolution of the shaft of the motor 2, the pressure in the lines x will increase to the value determined by the external load

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At the moment when the 11 windows 11 of the attached bottom 9 connected by the channel 10 of the jumper 9 of the distribution disk 12 are connected, the total length of the hydraulic connection exceeds the length of the jumper and thus the connection between the high and low pressure arrays, those. pressure relief occurs.

With further rotation of the shaft of the motor 2, the hydraulic connection is interrupted and a sharp pressure jump occurs in the pressure line due to a sharp increase in resistance to the flow of working fluid equal to the external load applied to the shaft of the hydraulic motor 2. Thus, during operation of the hydraulic machine, low pressure 14 and 15 hydraulic connection, causing cyclic pressure drops. The frequency of pressure change is determined by the speed of rotation of the shaft of the motor 2 and is controlled by the flow rate of pump 1, and the pressure amplitude depends on the cross-sectional area of the channel connecting the high 14 and 15 low pressure windows in the distribution disk 12.

Thus, the proposed method of life tests of volumetric hydraulic transmissions from axial-piston hydraulic machines allows, during testing, to adjust the cyclic frequency and amplitude of loading of hydraulic machines, without requiring additional energy costs for powering special pulsator devices.

Claims (1)

Invention Formula The method of accelerated resource tests of volumetric hydraulic transmissions, which consists in loading the hydraulic transmission under test by cyclically varying the pressure of the fluid, briefly connecting the high-pressure and low-pressure lines through a controlled hydraulic link, which is aimed at reducing energy losses, the loading mode is regulated by the angular velocity of the hydraulic machine shaft with simultaneous application of an external load to it. 13 it FIG. 2 Phie.z one 15