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Showing posts from January, 2019

Ultrasonic Thickness Measurement

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In the field of industrial ultrasonic testing, ultrasonic thickness measurement (UTM) is a method of performing non-destructive measurement (gauging) of the local thickness of a solid element (typically made of metal, if using ultrasound testing for industrial purposes) basing on the time taken by the ultrasound wave to return to the surface. This type of measurement is typically performed with an ultrasonic thickness gauge. Ultrasonic Testing (UT) uses high frequency sound energy to conduct examinations and make measurements. Ultrasonic inspection can be used for flaw detection/evaluation, dimensional measurements, material characterization, and more. To illustrate the general inspection principle, a typical pulse/echo inspection configuration as illustrated below will be used. A typical UT inspection system consists of several functional units, such as the pulsar/receiver, transducer, and display devices. A pulsar/receiver is an electronic device that can produce high voltage

Dynamic Balancing In Electrical Motor

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Mechanical Faults: Bearing Problems: ☛   Fundamental Train Frequency (FTF) ☛   Ball rotation frequency (BSF) ☛   Ball passage frequency, outer race (BPFO) ☛   Ball passage frequency, inner race (BPFI) Shaft Bend: Shaft ovality, shaft wear or damage Bearing housing looseness: Eccentric Rotor:  An eccentric rotor, which means the rotor core OD is not concentric with the bearing journals. Unsymmetrical Air Gap Around Rotor reference with stator produce uneven force at rotational speed (1x Speed). Electrical motors have the same mechanical faults that like other rotating machines, but there are also some specific faults for electrical motors. Thermal bending of the rotor: Uneven electrical circuits in the rotor bars generates an uneven heat distribution in the rotor. This causes a deformation, bending, of the rotor which results in unbalance. Eccentricity in the air gap: If the air gap is not uniform it generates unbalance forces on the rotor which in turn

On Site Laser Alignment

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Anytime two shafts are coupled together, the importance of precision shaft alignment is paramount. There are several ways of accomplishing this goal but the fastest, most accurate method is the use of lasers. The reasons have not always been obvious, but in the modern world the necessity of alignment is common knowledge. With today’s optimized machinery, alignment is a vital part in the daily maintenance work. Machines need to be online continuously with a minimum of interruptions. A machine breakdown causes devastating loss of production. Nearly 50% of all machine breakdowns are caused by misalignment. Shaft alignment can be performed with different tools. The easiest way is to use a ruler or a straight edge over the two coupling halves and align by eyesight. The result is not very accurate and it is very operator dependent. A better result can be achieved by the use of mechanical dial indicators. A skilled and experienced operator can obtain good and reliable measurement

On Site Vibration Analysis & Field Balancing

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The protection, consistency and effectiveness of rotating machinery are of a key apprehension in industries.  Condition monitoring  of a machines helps to retain the effectiveness and performance of a machine to its optimal level. The condition monitoring of a rotating machine is efficient, but often it is difficult and labor intensive task for maintenance crew to troubleshoot the machine. Vibration analysis  is a method used for condition monitoring of the machine. Effective vibration signal extracting techniques have a critical part in diagnosing a rotating machine. Many vibration signal extracting techniques have been proposed during past some years. The paper presents review of some vibration feature extraction methods applied to different types of rotating machines. Condition monitoring (or, colloquially, CM) is the process of monitoring a parameter of condition in machinery (vibration, temperature etc.), in order to identify a significant change which is indicative of

In House Dynamic Balancing

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Why Dynamic Balancing? Dynamic balancing is a way of balancing machines by rotating parts quickly and measuring the imbalance using electronic equipment. The imbalance measured can then be corrected by adding or subtracting weight from the rotating parts until the vibration is reduced. Basically, all machines have some form of residual vibration. Enormous vibration in rotating machinery can cause high levels of noise and more importantly, significantly reduce the life of components. So, the ideal thing to do would be to remove all causes of vibration and allow the machine to run completely smooth. The process of balancing is the removal or addition of weight to the device, so that this effective mass center approaches the true axis. Causes of Unbalance Material problems such as density, porosity, voids and blow holes can contribute to the unbalance condition. Fabrication problems such as misshapen castings, eccentric machining and poor assembly. ☛   Distortion prob