permissible with regard to its resi

permissible with regard to its resistance to mechanical
vibrations. The resistance of hydraulic valves to mechanical
vibrations is usually tested in accordance with the relevant
standards, such as, e.g. DIN-IEC68, part 2–6 [12] in the case of
the D1FP distribution valve. Valve mechanical vibration
resistance tests can also be conducted in accordance with
other procedures described in Polish and international
standards. Standard PN-IEC 68-2-59 1996 [13] specifies a
method of testing electrotechnical subassemblies, equipment
and other products (including hydraulic valves used in
electrical applications) which during operation may be
exposed to short-duration pulsating or oscillating forces
generated by, e.g. seismic phenomena, an explosion or the
vibrations of the machine in which they are installed. The
tested product is excited by a certain number of constantfrequency
sinusoidal beats. Standard PN-EN 60068-2-6:2008
[14] specifies a method of testing subassemblies, equipment
and other products, which during transport or operation may
be exposed to harmonic vibrations generated mainly by
rotating, pulsating or oscillating masses. Such excitations
occur in ships, planes, terrestrial vehicles and space vehicles.
Resistance to mechanical vibrations in a frequency range of
5–3000 Hz is tested. A critical frequency identified by the test is
a frequency at which faulty operation of the product or a
deterioration in its properties due to vibration manifests itself
or mechanical resonances (e.g. a valve control element) occur.
Polish standard PN-EN ISO 4413:2011 [15] includes, among
other things, requirements for the assembly of hydraulic
valves (also pumps, servomotors,
filters, etc.), but limited to a
general statement that one should consider the effect of
gravitation and vibrations on the valve.
In general, the vibrational resistance standards specify the
permissible level of external mechanical vibrations which may
adversely affect a machine, a piece of equipment or their
components. In the precision industry, the experimentally
determined maximum acceleration of about 0.981 m/s2 has
been adopted as the norm ensuring the vibrational resistance
of measuring instruments and industrial equipment [16]. As
regards rotor machines, they can be exposed to external
mechanical vibrations below 9.81 m/s2, without any adverse
effect on their operation.
In this paper, the possibility of reducing the vibrations of
the hydraulic distribution valve is studied. The experimental
studies have been broadened with a general theoretical
analysis of the problem of reducing the vibrations of a valve
or a control element, which can be helpful in selecting the
characteristics of antivibration materials and vibration damping
systems for this purpose.