June 16, 2020 By Brady Hugo, Hydraulic Engineering Supervisor

Many of us know the sound and irritation of loading the washing machine too full. During the spin cycle of the wash, if the weight within the washing machine is off-center or too heavy, the machine will sound like it is shaking itself to pieces. This tends to terrify my 4-year-old daughter.  

Other household appliances will show this same phenomenon. While not as dramatic, the fridge does something similar, when the compressor motor shuts down and there is a split second where the motor and compressor pump spins at a much lower speed. This lower speed will match the system response frequency of the dampeners and will shake much harder. 

https://www.uea-inc.com/blog/rotary-union-design-blog-series-vibration-resonance-and-system-responseIf this were an engineering class, the instructor would simplify this example down to 3 components, a weight, spring, and dampener. Together, these components make up a system, and its system response would be the frequency that the system vibrates at, given an input force. Appliances, such as of a fridge and washing machine, typically use rubber feet to act as the spring and dampener. Read More