Gear Grinding

Grinding is one of the most precise of all the primary machining processes. Gear grinding has effectively prolonged the life cycle of many a high-performance gear by helping the manufacturers in precisely predicting the end of life cycle and predictive check up requirements.

Grinding machines typically use a wheel that is made up of one of the manufactured abrasives, aluminum oxide or silicon carbide. For grinding a cylindrical tooth form, the workpiece is rotated while it is fed against the grinding wheel. For grinding an internal surface, a small wheel is pushed inside the hollow part of the workpiece, that is gripped in a rotating chuck. In case of a surface grinder, the workpiece is typically placed on a table which is then moved under a rotating abrasive wheel. Let's understand how a Gear grinding process evolves.

Types of Gear Grinding Process
There are generally two types of gear grinding process.

Generation Grinding
Generating grinding utilizes identical mechanisms as that of gear hobbing but uses a threaded worm grinding wheel for achieving highest accuracy and efficiency.

Profile Grinding
To overcome the limitation of generation grinding Profile grinding is now more common. The problem with generation grinding is that it is not able to produce what is called a true involute profile. Generation grinding produces tangents to an involute form. In stark comparison, Profile grinding has high-accuracy dressing units and it is able to form the grinding stone for each specific gear, pitch, as well as profile. The Profile grinding is quite capable of producing the correct involute form. The image shows the difference between the two.

Gear Grinding Wheels
Gear grinding wheels are applied for rectifying or for modification of a gear tooth lead and profile, subsequently after heat treatment. The wheel shape employed is guided by the type of machine as well as the gear that needs to be ground.

   
Single profile Gear grinding Wheel
This is used for single index generation grinding

 

Bevel Gear Grinding Wheels
These special grinding wheels are also known as Form 2 grinding wheels.

   
Thread Grinding Wheel
The Gear teeth of Helical and Spur Gears are easily ground with Thread Grinding Wheel. It gives good efficiency because of multiple threads.

Gear Grinding Machines
To carry out the gear grinding work precisely a variety of gear grinding machines are found today. Some of them have been highlighted here.

Features of a Fine Grinding Machine