Following are the types of grinding machines:
1.Bench Grinder: These types of grinding machines are fixed on a workbench or table. Gear or pulley is fitted in it. For rotating the big-size gears or pulley a handle is also fixed. It contains one or two grinding wheels. Edges of cutting tools can be made with this grinder. Provision can be made to operate these with power also.
2.Hand Grinder: This grinder is also fixed on the workbench or table. There is a provision of moving the grinding wheels with a level.
3.Pedestal Grinder: These types of grinding machines are operated with electric power. This is fitted on a pedestal frame separately on the ground. A grinder wheel is fitted each on both sides of the shaft of the electric motor.Tools rests are also provided with them. These are the most widely used in the workshops
4.Portable Grinder: This is a small grinder operated with electric power. It can be easily carried anywhere. Grinding can be done by holding it in hand. It is used for cleaning heavy welding jobs.
5.Flexible Grinder: Flexible shaft is fitted on the motor shaft with the help of a coupling. On one end of the shaft, a grinding wheel and handle are provided. Large jobs can be easily grinded with this grinder.
6.Precision Grinder: In this type of grinder, a movable spindle is fitted in the grinding wheel. This spindle is fitted on a table along with its motor. With this spindle, the grinding wheel can be turned in forward, backward, left, or right direction in running condition. Jobs of excellent finish and accuracy are grinded with it.
7.Surface Grinder: A surface grinder is a reciprocating grinding machine used for making flat surfaces on workpieces. It can form surfaces with greater precision.
8.Swing Frame Grinder: This grinder consists of a 2 or 3-meter long frame with a grinding wheel that is suspended at its center of gravity so that it can move freely.
Classification of Grinding Machine
Basically Grinding machine can be classified into two categories which are:
1.Non-Precision Grinding Machine: By this grinding machine, such materials are removed from workpieces that are rough such as materials made from casting, forging, etc.
Non Precision Grinders are :
1.Bench Grinder
2.Pedestal Grinder
3.Portable Grinder
4.Flexible Shaft Grinder
5.Swing Frame Grinder
2.Precision Grinding Machine: By this grinding machine, such materials are removed from workpieces that are soft and required precise surface finished.
Precision Grinders are:
Surface Grinder
1.Horizontal Spindle Reciprocating Table Horizontal Spindle Rotary Table
2.Vertical Spindle Reciprocating Table
3.Vertical Spindle Rotary Table
Cylindrical Grinder
1.External Cylindrical Grinder
2.Internal Cylindrical Grinder
3.Universal Cylindrical Grinder
4.Centerless Grinder
A.Tool and Cutter Grinder
B.Special Purpose Grinding Machine
Other Grinding Machine: It may be precision or non precision grinding machine.
1.Wet Grinding : In most of the grinding machines, there is a provision of a regular flow of coolant apparently on the workpiece where the wheel touches.
2.Dry Grinding : There is no arrangement of coolant system with the grinding machine and the workpiece is finished on that grinding machine then it is called dry grinding.
Grinding Defects
There are the following grinding defects found during the grinding operation.
1.Overheated Spots
2.Chatter Marks
3.Rapid wear of the Wheel
Causes of Overheated Spots
The excess wheel speed and feed.
Wheel in glazing condition.
Not using enough coolant.
Remedies of Overheated Spots
Use the right speed and feed.
Dress the wheel.
Use sufficient coolant
Causes of Chatter Marks
Wheel not mounted properly.
Slackness in the spindle.
Wheel unbalanced.
Not clamping properly job.
Excess cut depth for the machine.
Remedies of Chatter Marks
Mount the wheel correctly.
Remove slackness of spindle.
Balance the wheel.
Clamp the job properly.
Use the correct cut depth.
Causes of Rapid Wear of the Wheel
Wheel too soft.
Grinding wheel speed is less than the permissible speed.
Remedies Rapid Wear of the Wheel
Use the correct grade of the wheel.
Increase the wheel speed to the approved speed.