Mechanical Engineering

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A servomechanism, usually shortened to just servo, is a device used to provide mechanical control at a distance. For example, a servo can be used at a remote location to proportionally follow the angular position of a control knob. The connection between the two is not mechanical, but electrical or wireless, for example.

The most common type of servo is that mentioned, which gives positional control. Servos are commonly electrical or partially electronic in nature, using an electric motor as the primary means of creating mechanical force, though other types that use hydraulics, pneumatics or magnetic principles are available. Usually, servos operate on the principle of negative feedback, where the control input is compared to the actual position of the mechanical system as measured by some sort of transducer at the output. Any difference between the actual and wanted values (an "error signal") is amplified and used to drive the system in the direction necessary to reduce or eliminate the error. A whole science of this type of system has been developed, known as control theory.

Servos are found in many applications. They operate the throttle of engines that use a cruise control. CNC machines use servos to make the motion axes of a machine tool follow the desired tool path. Fly-by-wire systems in aircraft use servos to actuate the control surfaces that control the aircraft. Radio-controlled airplanes use servos for the same purpose. Many autofocus cameras also use a servomechanism to accurately move the focus.

one million US dollar per year

The performance of a pneumatic system is dependent upon the air displaced or handled, which is directly proportional to the stroke and diameter. In other words, it is to be considered like a cylinder whose volume increases with diameter and length.

Either it will not run at all, or run very poorly. Either is likely to do severe damage to the engine.

To replace the generator rectifier, remove the old one by removing the two bolts on the sides. Lift the cover boot up and unplug the connector. Take the new rectifier and bolt it on, then plug in the connector. It snaps right back on. Push the boot cover back down.

It is based on the flow area, which is proportional to the square of the diameter. 2 squared = 4. 4 squared = 16. So, the 4 inch pipe can take 16/4 = 4 times the volume of the 2 inch pipe. It might be less confusing if you had picked sizes other than 2 and 4. This is a rough calculation, since pipe inside diameters are not the same as nominal sizes, but close enough for most purposes.

Because there is always going to be friction, the efficiency of any machine will always be less then 100 percent.

because the cast iron is a ferrous metal

Foam contains pockets of trapped air which prevents conduction.

Iron with differrent carbon percentage in it would have different strength and ductile properties at different temperatures.As the percentage of carbon increases its ductility decreases and strenght increases and brittleness increases.This is put in a diagram that explains the condition of iron with different carbon percentage.This is iron carbon system.

Not necessary some are electrical Not necessary some are electrical Not necessary some are electrical

A standard specimen is loaded on a tensile test machine; load,P, is applied and measured with a load cell and strain, e, is measured with a strain gauge extensometer. In the linear region, load is divided by specimen area to get stress, s, and the modulus, E, is determined from Hooke's law, where E = s/e

Most cutting and welding is done with a neutral flame.

ni hard material lubrication is required or not

It's a guy in a suit.

only water is used in boilers to reduce the cost. and if other liquid like petrochemicals will be used than the cost will be more and there will be the higher risk because if the boiler bursts than it will cause more damage than water boiler.

The distance between steps shall not exceed 12 inches, thus two rungs equal 24 inches

In the normalising metal treatment process, the metal is cooled slowly and gradually while in quenching metal treatment process the metal is called very fast and abruptly.

Typically, a stud bolt refers to an un-headed fastener, like a piece of all thread rod. A hex bolt is common a six-sided fastener, available in many grades.

Here's a site that does it for you quite simply: http://www.susdesign.com/windowheatgain/index.php

A blimp and dirigible are the same thing.

The first plane motor was constructed in 1924 by Erron Jovach in Germany.