vibration machine[vī′brā·shən mə‚shēn]
a machine in which the oscillatory motion necessary to complete or intensify a process is im-parted to the working member. The frequency of the vibrations of such machines varies from several hundredths of a hertz up to 10 kilohertz (kHz), and the amplitude of the vibrations ranges from 1 m to fractions of a micron.
Vibration machines are classified according to the type of drive (mechanical, electrical, hydraulic, and pneumatic), the way in which the power supplied to them is converted into the energy of mechanical vibrations (centrifugal, in which the vibrations are caused by the motion of unbalanced rotors [disbalances]; reciprocating; cam; crank; electromagnetic; electrodynamic; magnetostrictive; and piezoelectric), the spectral composition of the induced vibrations (harmonic [sinusoidal], biharmonic, or polyharmonic), the path described by points on the working member (rectilinear, circular, elliptical, spiral, and so on), and the presence of impacts (nonpercussion or vibration-percussion).
Vibration machines have become widespread in construction and the construction-materials industry for compacting cement mixes and soil and road coverings, for forming reinforced-concrete parts, for working frozen soil, and for sinking piles, sheet piles, and pipes; in machine building they are used in preparing casting molds and cores and for knocking out molding boxes, for vibration processing and vibration cutting, for supplying automated machine tools with correctly oriented blanks (vibration hoppers), and for transporting blanks and parts between operating stations on auto-mated production lines (vibration conveyors); and in mining they are used for screening (vibration screens) and for drilling, loading, and moving spoil. Vibration machines are also used in transportation for unloading compacted or congealed materials, loading and unloading granular materials, and compacting broken stone ballast; in machines of the food industry and agriculture (vibration grids and separators, vibration pumps, and vibrating poultry feeders); in public utility services (laundry equipment and machines for removing compacted snow and ice from roads); in medicine (massage machines and dental drills); and in many other fields.
REFERENCESPovidailo, V. A., R. I. Silin, and V. A. Shchigel’. Vibratsionnye ustroistva v mashinostroenii. Moscow-Kiev, 1962.
Vibratsionnye mashiny v stroitel’stve i proizyodstve stroiteVnykh materialov: Spravochnik. Moscow, 1970.
I. I. BYKHOVSKH
B. G. GOL’DSHTEIN