Pneumatic Surface Grinding Machine

Pneumatic Grinding Machine

Umesh Kumar Meher

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Pneumatic Grinding Machine

Pneumatic :

Grinding :

Pneumatics is a section of technology that deals with the study and application of pressurized air/gas to produce mechanical motion.

Grinding is a process carried out with a grinding wheel made up of abrasive grains for removing very fine quantities of material from the work piece surface.

Different Types of Grinding Machine

• Utility grinding machines

• Floor mounted utility grinding machine

• Bench type utility grinding machine

• Bench-type utility drill grinding machine

• Milling and grinding lathe attachment

• Surface grinding machine

Surface Grinding Machine

The surface grinding machine is used for grinding flat surfaces.

The work piece is supported on a rectangular table which moves back and forth and reciprocates beneath the grinding wheel.Reciprocating surface grinding machines generally have horizontal wheel spindles and mount straight or cylinder-type grinding abrasive wheels.

Pneumatic Grinding Machine

Important Parts

Power Input Source (Air Compressor)

Pneumatic Motor

Grinding Wheel

Work piece

Air Compresser

An air compressor is a device that converts power (usually from an electric motor, a diesel engine or a gasoline engine) into kinetic energy by compressing and pressurizing air, which, on command, can be released in quick bursts.Specification

Pneumatic Motor

A pneumatic motor or compressed air engine is a type of motor which does mechanical work by expanding compressed air.

The pneumatic motor used in our project is known as a rotary vane motor, uses air to produce rotational motion to a shaft. The rotating element is a slotted rotor which is mounted on a drive shaft. Air is pumped through the motor input which pushes on the vanes creating the rotational motion of the central shaft.

Rotation speeds can vary between 100 and 25,000 rpm depending on several factors which include the amount of air pressure at the motor inlet and the diameter of the housing.Model BVS 130

Weight 0.286/.587 kg

Dia of pneumatic turbine 70.6mmDia of rotor 67.6mm

Dia of spindle 7.93mmDia of inlet and outlet port 3.9mm

Specifications

Grinding Wheel

A grinding wheel is an expendable wheel that is composed of an abrasive compound used for various grinding (abrasive cutting) and abrasive machining operations.

Abrasive Type

Grit Size Grade Structure Bond

A 126 H 5 S

Al2O3 Fine Soft Close Pack Silicate

Grinding Wheel Specification

Grinding wheel Specification

Work pieceAbrasive material Percentage Work material Colour

Aluminium Oxide97-99% Al2O3 Hardened steel, HSS White

87-96% Al2O3Steel, cast iron Pink to brown

Silicon Carbide96-99% SiC HSS,

cemented carbides

Green

<96% SiC Aluminium , brass, brittle

materials

Black

Cubic Boron Nitrate (CBN) Tool steels, aerospace alloys

Synthetic Diamond Ceramics,

cemented carbides

Working Principle

Pneumatic Turbine

Rotation of Grinding Wheel

Grinding Operation

Air CompressorCompressed Air

The compressed air from the air compressor passed through the inlet port of the pneumatic turbine.

The high pressure and high velocity air then strike the vertical blades/slots.

This compressed air cause the blades to rotate in very high range, ranging from 1500 to 12000 rpm depending upon the supply of compressed air.

This rotor then cause the whole pneumatic circuit to rotate thus the spindle and shaft connected to it rotates.

Then the spindle rotation cause the rotation of the grinding wheel connected to it.

The compressed air once strike to the blades again comes out of the turbine by an exhaust port that present in the turbine.

AdvantagesThe grinding/grinding speed can be varied according to our needs by adjusting the timer.It is portableIt does not have any Prime mover, like electric motor related to the unit.As the air is freely available, we can utilize the air to cut the metal and hence it is economical.Simple in construction than mechanical hacksaw and grinderIt is a compact oneLess MaintenanceNo lubrication requiredNoiseless Can be rotate in both clockwise and anti-clockwise direction

Limitation

Only smaller size and soft metal can be cut

It is costlier than the conventional one

because of compressor unit.

Less efficiency when compressed to

mechanical device.

Leakage of air affects the working of the

unit.

High initial cost

References•Rao N P , Manufacturing Technology, volume-2, Metal Cutting And Machine Tools, 2nd Edition, Tata McGraw-Hill Publication, New Delhi, 2009•Mallik Kumar Asok Ghosh Amitabha, Manufacturing Science, 2nd Edition, EWP Publication, New Delhi, 2010•http://en.wikipedia.org/wiki/Pneumatic_motor•Pneumatic engines for power tools (http://www.directindustry.com/cat/motors-geared-motors-motion-control/pneumatic-motors-D-77.html)•Engineers Edge. Pneumatic actuator design and operation. Retrieved from http://www.engineersedge.com/hydraulic/pneumatic_actuator.htm•Braun, Adolphe: Luftlokomotive in "Photographische Ansichten der Gotthardbahn", Dornach im Elsass, ca.1875•http://en.wikipedia.org/wiki/Grinding_wheel•http://www.smithy.com/machining-handbook/chapter-8/page/3•http://www.vibco.com/docs/catalogs/silent-pneumatic-turbine-vibrators-catalog.pdf•http://www.durhamgeo.com/pdf/Rem-pdf/p32.pdf•http://www.iontrap.wabash.edu/publications/ajp_80_24_rohrbach_air_cannon.pdf

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