Methodology for assessing the vibration activity of an aggregated hydraulic device under test bench conditions

In this paper, we consider the issue of evaluating the vibration activity of complex multichannel aggregated hydraulic devices (AD) that combine in their design several simultaneously involved working elements (throttles, spool valves), flow channels of complex geometry, and control elements of various modes. In such conditions, it is extremely important to determine the contribution of the main elements to the resulting vibration characteristic of the device. To perform these works, it is necessary to develop an order and methodology for their implementation. The paper presents the main provisions of the developed methodology and the results of their implementation, including the following sequence of actions:

• Before installing the AD on the bench, the natural frequencies of free vibrations of the structure and its elements were determined by its free suspension. The results obtained were taken into account in the subsequent analysis.
• A program for measuring the vibration characteristics of the AD in various hydraulic modes of operation was developed. A map of vibration control points was compiled, determining the characteristics of specific structural elements of the AD design.
• A form of presentation and analysis of vibration characteristics at measurement points with a temperature distribution of the results over 1/3 octave frequency bands was developed.
• The planned tests were carried out, the results were analyzed, and the directions of work to improve the design of the AD and its test conditions were determined.

The results of applying the above methodology in testing the vibration activity of the experimental AD sample made it possible both to determine the direction of improvement of its design and to optimize the operating modes of the main working bodies.