Ultrasonic Machining USM - Applications Advantages and Disadvantages

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🔗Working of ultrasonic machining equipment USM
🔗Factors affecting ultrasonic machining

Applications of Ultrasonic Machining USM

  • USM technology is used to the machining of brittle material and material of high hardness due to the microcracking mechanism.
  • USM can be used to drill holes of straight and curved axes.
  • For drilling holes in wire drawing dies.
  • Threading of hard material and alloys by rotating and translating the movement of either tool or workpiece.
  • Unlike other metal removal process, such as chemical, thermal processes, USM method does not harm the physical properties of workpiece and it maintains crystallographic properties. So they are used for machining of more brittle and high sensitive material.

Ultrasonic Machining USM Process Parameters and Factors Affecting Ultrasonic Machining Rate

Process Parameters and Factors Affecting Ultrasonic Machining
🔗Working of ultrasonic machining equipment
🔗USM applications, advantages and limitations

Process variable and their effect on the ultrasonic machining

The machining rate and accuracy of USM depend on many factors. Diagram shows some of the factors that affect the USM.

USM Machining Rate

The cutting rate in USM depends on

1. Vibration frequency and amplitude: The frequency of vibration is directly proportional to the material removal rate. The increase in frequency increase the number blows by the tool per second and cut more material from surface. For many materials, the material removal rate is proportional to the square of amplitude of vibration.

Ultrasonic Machining USM Equipment Elements and Working

ultrasonic machining
Read: Abrasive jet machining (AJM) construction and working

Ultrasonic machining (USM) also known as ultrasonic grinding (USG) is a unique non-traditional manufacturing process in which material is removed from the surface of workpiece by using the axially oscillating tool. The tool is vibrating at high frequency and low amplitude in the presence of fine abrasive particles. USM is used in precision machining of hard and brittle material. It can achieve dimensional accuracy up to ±0.005mm.

Comparison between Stationary Blade and Rotating Blade Type Rotary Compressor (Rolling Piston Vs Rolling Vane)

stationary blade and moving blade rotary compressor1
🔗Working of stationary blade rotary compressor
🔗Working of moving blade rotary compressor
  • Both rolling piston and rolling vane compressor, it compresses the fluid by decreasing the space between the roller and cylinder.
  • In both types, the blade is allowed to move up and down (reciprocate) in the slot to make a sealed compartment between cylinder and roller.

Difference between stationary blade and moving blade type rotary compressor

  • In rolling piston, the roller is eccentrically mounted on a shaft which is concentric to the cylinder. In rolling vane, the roller is concentrically mounted to a shaft which is eccentrical to the cylinder.
  • In rolling piston type, the roller rolls around the inside wall of cylinder and blade move up down to make contact with the roller. In rolling vane type, the roller rotates inside the cylinder (not rolls around the wall) and the blade moves up and down in the slots on the roller to keep contact with the cylinder wall.
  • In rolling piston, the blade separates low pressure and high-pressure side while the roller rolls over the inside wall of the cylinder. In rolling vane type, the roller tightly touches only at the point between suction and the discharge port and this separates high pressure and the low-pressure side of the compressor.

  • Rolling piston rotary compressor has only one blade. Rolling vane compressor has more than one blade. It may have as many as eight blades. More the number of blades more the efficiency will be.

  • In rolling piston type, the single blade/ vane is attached in the slots on the cylinder. While in rolling blade type, the vanes are attached on the slots of the roller and it rotates along with roller.

Difference between Reciprocating Compressor and Rotary Compressor

reciprocating vs rotary compressor

🔗Reciprocating compressors working, applications, advantages and disadvantages
🔗Rotary compressor working, applications, advantages and disadvantages

Reciprocating compressor
Rotary compressor
Fluid compressed by reciprocating motion of piston.

Fluid compressed by rotary motion of blades.
Prime mover (motor or engine) and compressor is separated, so they are heavy and bulky for a given discharge volume.
Prime mover and compressor and compressor are pressed in to a cylinder, so they are small and light.

High clearance volume.
Negligible clearance volume

Low volumetric efficiency when compared to rotary compressor
High volumetric efficiency compared to reciprocating compressor.

Low speed compressor.
High speed compressor.

High pressure ratio per stage is achieved.
Discharge pressure per stage is low when compared to reciprocating compressor.

The quantity of fluid it can handle is very low
 Since it operates at high speed it can handle high volume fluid.

Used for high and medium pressure ratio and for low and medium volume.
Used for high and medium pressure ratio and large volume.

Greater vibration and shaking due to reciprocating action. The machine parts are poorly balanced.

The machine parts are fairly balanced, it has very less vibration.
Since heavy vibration and shaking it require rigorous foundation.
Since less vibrational problem it do not require rigorous foundation.

High maintenance required
Well balanced machine so it require less maintenance.

The supply of compressed fluid is intermittent.
Supply of compressed fluid is continuous.

Complicated lubrication is required
Simple lubrication.

The fluid (air) is directly comes in contact with lubricating oil, so the discharge is often dirty.

The discharged fluid is clean and free form dirt.
It has greater flexibility in capacity and pressure range.

No flexibility in capacity and pressure range.

Construction and Working of Rotating Blade (Rolling Vane-Type) Rotary Compressor

Rotary vane compressor working cycle

🔗Rotary compressor working, applications, advantages and disadvantages
🔗Working of Stationary blade type (Rolling piston) rotary compressor

Rolling vane type compressor has a roller inside a stationary cylinder. Roller has two or more vanes positioned in the slots of the rotor. Vanes rotate with the roller and ride on the cylinder wall. The roller may have as many as eight vanes. The more the number of vanes it has the more the efficient compressor will be. A roller moves the vanes slides in and out of the roller to create a sealed space for compression. As roller continues to rotate this space get decreased, and causing compression of fluid (refrigerant) trapped inside this space during the suction.