Actuating Mechanism

Actuating Mechanism


(also servomotor), a device designed to move a control member in automatic-control or remote-control systems and to be used as an auxiliary drive for units in servomechanisms and vehicular steering gear. A change in the position of the control member produces a change in the flow of energy or material to an object and thereby affects the operation of machines, mechanisms, and technological processes by eliminating the deviations of the controlled variable from its prescribed value. An actuating mechanism not only changes the state of the object being controlled but also moves the control member according to a specified control principle, with the minimum possible deviations. In most cases it is operated by external power sources, since direct control by means of an actuating mechanism consisting of primary control units such as relays and transducers is impossible because of their low power, which is insufficient to act on a control member.

An actuating mechanism usually consists of a motor, a transmission, and control units, as well as feedback, signaling, interlocking, and shutoff units. Actuating mechanisms to control the flow of fluids or gases consist of a valve, shutter, or gate, which is moved by hydraulic, pneumatic, or electrical drive. Diaphragm and piston drives are used in pneumatic automation systems. Electromechanical actuating mechanisms are extensively used in industrial automation; they are usually driven by an induction motor, but in some cases they are driven by an electromagnet (solenoid), the use of which is limited because of its abrupt (jerky) action on the member being controlled. Hydraulic mechanisms operate at pressures up to 3 mega-newtons per sq m (MN/m2), or 30 kilograms-force per sq cm (kgf/cm2); pneumatic mechanisms, at pressures up to 0.6 MN/m2(6 kgf/cm2). Most electric mechanisms have electric motors with powers ranging from 10 watts to 1 kilowatt or more.


Osnovy avtomaticheskogo regulirovaniia, vol. 2, part 1. Edited by V. V. Solodovnikov. Moscow, 1959.
Mironov, K. A., and L. I. Shipetin. Avtomaticheskie reguliatory: Spravochnye materialy. Moscow, 1961.
Avtomaticheskie pribory, reguliatory i upravliaiushchie mashiny, 2nd ed. Moscow, 1968.


References in periodicals archive ?
Contract Awarded for The bid inviting of this time is for a set of hydraulic oil source system, Mainly used for providing oil source power for loading actuating mechanism in intensity test, Which is the most basic test conditions and equipment so that the static and fatigue tests of the level of aviation structural component and grouped component can be made as soon as after equipment acceptance is qualified, Mainly including a set of hydraulic oil source and a set of hydraulic sub-stations.
The cams which act directly on the cam followers or bucket tappets do not increase the valve actuating mechanism reciprocating mass and do not rely on electrical or hydraulic systems to control the valve events.
The actuating mechanism in the case of micro flaps requires low actuation forces due to the small size of the element.
The actuating mechanism (power adapter unit or battery-run) uses ball-bearing based gear motors -- currently the most reliable and most silent on the market.
The only aspect linked to the actuating mechanism (by compressive air) didn't be updated the last 100 years, diminishing a lot the technical potential of these equipments, due to the following causes: the high costs of energy, the low energetic efficiency, due to the losses on the network and the mass of the equipments.
Items are dispensed by an actuating mechanism that removes the bottom item from the vertical stack individually based on order requirements.
The valve actuating mechanism can be released several ways, depending on the medium available and the individual requirements.
The actuating mechanism is arranged outside the actual nozzle, eliminating any compound leakage around the needle.
It can take up less room and requires a simpler, less complex actuating mechanism for beds, stretchers, tables, carts or other equipment to which it is attached.
One of the most striking features of HCCI is the absence of an actuating mechanism to directly regulate start of combustion, such as spark timing or injection timing, making control over a range of operating conditions challenging.
The new jaw (or reversed jaw) is then inserted into the guideway, positioned, and the key is turned one-quarter turn counterclockwise to reengage the actuating mechanism.