The world’s first closed loop, resonant frequency control system – abbreviated as RVS – vibratory tray feeders and conveyors were designed and patented in 1982 by ARBO-Analogtechnik SA of Lugano, Switzerland. Prior to the development of the ARBO RVS controllers for vibratory feeders was mainly limited to open loop, fixed frequency technology with significant limitations in range, performance and reliability.
What does a “resonant frequency vibratory control” system do? A resonant frequency vibratory control system controls the stroke, or amplitude” of tray vibration over the designed operating range at the resonant frequency of the vibratory tray.
What is “resonant frequency vibration” ? In simple terms, “resonant” or “natural” frequency could be described as the cyclical period (time base) of oscillation by a spring-mass machine which conforms closely with Newton’s First, Second, and Third Laws of Motion and with Hookes Law of Spring Proportionality.
Essentially, Newton’s laws of motion and their derivatives declare that the relationship between mass, force, acceleration, and velocity are proportional and constant excluding external influences.
F = MA
Hooke’s Law declares that deflection of a spring is perfectly proportional to an applied force within the elastic limits of the spring material.
F = KX
How do you get an ARBO resonant frequency vibratory feeder from that? ARBO resonant frequency vibratory feeders are spring-coupled dual-mass oscillatory machines that operate at their natural frequency and continuously recycle operating energy between the kinetic, or moving state, and the potential, or stored state.
Advantages of the ARBO closed loop, resonant frequency vibratory controls?
• Closed loop amplitude control provides precise amplitude control even with varying material density and tray or hopper loading. It also allows maintaining a precisely linear relationship between vibratory amplitude and setpoint over the entire operating range of approximately 0 – 3.5mm.
• Resonant frequency control permits an extremely broad range of operation – up to 1000:1
• Start cycle at 0.2 sec- Stop cycle at less than 0.1 sec, with smooth energy efficient operation over the entire range.
• Automatic resonant frequency determination over the normal operating range of 35 – 65 hertz with no tuning or calibration required.
What about the ARBO Vibratory feeder itself? Arbo vibratory drives are comprised of an electromagnetic coil and the tacho feedback sensor as illustrated in the cut-away drive below. Arbo vibratory drives have the following advantages:
No moving parts, no wear, low energy consumption, no mechnical adjustment or tuning, long service life and consistant performance, accuracy and repeatability.
We at ARBO look forward to working with you on your feeder application and can be reached at 416 636 7057 or [email protected]
