An overhung machine is one where the fan or impeller lies outside of the bearings that support the shaft. Figure 1, below, shows an illustration of an overhung impeller. Figure 1. Overhung impeller connected to a motor Overhung machines tend to have high 1X forces…
read moreBelt drives are widely used in many industries for power transmission since they are cheap and easy to maintain. However they are often a source of vibration due to misalignments, belt resonance, and belt wear. The main purpose of belt drives is to transfer power…
read moreIt is essential to design a device that has to meet a certain vibration level. Ideally, the desired vibration response must be clearly stated before a design can begin. Many different methods have been proposed to measure and describe acceptable levels of vibration in many…
read moreIn a previous post I discussed electric motor testing, specifically static or offline testing. This week I would like to tackle the subject of dynamic or online testing of electric motors. As the name suggests, dynamic tests are performed while the electric motor is running i.e. when it…
read moreMachines are expected to vibrate as little as possible to avoid component fatigue/failure and in some cases, reduce user comfort level, for example, violent vibration of an automobile can lead to mechanical failure and driver discomfort. There are ways to avoid violent vibration such as…
read moreElectric motors are a key component for running machines in most industrial environments. Therefore it is important that they are properly monitored to avoid unwanted failures or shutdowns. Typically, there are two testing categories for electric motors: 1. Static or offline tests 2. Dynamic or…
read moreSome boats vibrate more and make a lot of noise. Vibration and noise in boat require immediate attention. Vibration and noise are related; vibration generates unwanted noise. Below are some ways to decrease vibration and noise on your boat: Boat PropellersOne of the most common…
read moreAliasing is a phenomenon that can occur due to improper sampling or data collection, where the original signal is indistinguishable when reconstructing data from the collected samples. This usually occurs because the sampling rate and/or resolution is inadequate. Figure 1 shows an example of aliasing. The original…
read moreThere are two vibration situations in which statistical analysis is useful. The first situation occurs when the vibration amplitude of a system appears to be random in time. In this case, it is convenient to describe the response of the system statistically. This form of…
read moreEvery product starts out on the drawing-board with a set of objectives that define what the product must accomplish. Before clearly setting objectives for the design, it is critical to understand the constraints that may prevent it from achieving all the intended goals. Constraints inherently…
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