Question

Please create a presentation slide about five (5) vibration control examples for home appliances.
The presentation slides must be in Microsoft PowerPoint (*.pptx) format.

Answer 1

Vibration control in the refrigerators

In most domestic refrigerators the compressor is hermetically contained inside a shell and the room between the compressor and the shell is used as a refrigerating fluid and lubricating oil tank. The refrigerating fluid occupies the acoustic cavity which is over oil level and is stimulated by many pressure fluctuations, they arc caused by the impulsive motion of the suction valve, by the motion of the refrigerating fluid which enters and leaves the cavity and by the vibration of the compressor body. These phenomena cause the forced vibration of the fluid, the vibration amplitude becomes large when one of the acoustic modes of the cavity is stimulated in resonance condition; since pressure fluctuations have many spectral components the possibility of stimulating an acoustic mode in resonance condition is high. Large acoustic vibrations of the fluid inside the cavity have to be avoided because they increase noise emission and disturb compressor operation. A Helmholtz resonator can reduce the amplitude of the most excited acoustic mode of a compressor cavity.

Vibration control in the air conditioners

Two different concepts for the design of active compressor mounts were developed that are used to reduce the vibration excitation of the air conditioner unit's housing. The first one is an active tuned vibration absorber whose natural frequency can be adapted by means of piezoelectric patch actuators and which behaves as a vibration compensator at higher frequencies. The second one is an active mount based on four piezoelectric stack actuators and an elastomer part that deflects the effective direction of the piezo stack displacement by 90 degrees while amplifying the displacement by a factor of approximately 30.

Vibration control in the washing machines

Washing machines contains compressors that cause large vibrations when operated. High-performance vibration dampers are essential for suppressing this type of vibration, to maintain product performance, and to prevent vibrations from affecting our living environments.Vibration in the washing machines can be controlled by different ways.The vibration damping pads are to be placed under the four corners of the machine. They reduce noise,vibration prevent the machine from moving and create a gap between the floor and the washing machine. When setting up a machine, to ensure that all four feet are adjusted and the washer is level.If stacking kit was not attached properly or is missing, it could cause the stacked washer to be off-balance and to vibrate, especially during the spin cycle. So this should be avoided.

Vibration control in the ceiling fans

A vibrating ceiling fan catches the eye, may cast shaky lighting, and sometimes produces an annoying buzz. The vibration is most likely the result of a wobble in the fan that could be caused by some loose screws, or a fan blade out of balance. Besides being annoying, the vibration could lead to loose wires or rapid wear of moving parts if left unchecked. Check the screws that hold the fan blades to the blade holders, and the ones that hold the blade holders to the fan motor’s flywheel. Tighten any loose screws. Clean all the fan blades with a damp cloth, then dry them off with a clean, dry cloth.

Vibration control in the mixer grinder

A mixer grinder is used in kitchen for cutting the vegetable items into small particles, prepare foods and make juices. It’s having a gear-driven mechanism to rotate a set of beaters in a bowl containing the food to be prepared. It automates the repetitive tasks of stirring, whisking or beating. Electric mixers with more speed options give the user more control over the development of the mixture.Maximum advantages of reducing noise and vibration at the source can be realized by careful planning, thoughtful design, and proper choice of materials and structures specifically engineered for the task. This technological state of the art in damping materials and systems is such that it is possible to design products that operate more quietly, with less vibration and greater precision, without being necessarily more expensive or difficult to build.