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.

• Gear blanks is roughed out.
  
  
• Stresses relieved for reducing the distortion after the process of carburising.
  
  
• Blanks get finish machined with a material allowance on critical diameters.
  
  
• Gear cutting process is then performed with proper allowance on the tooth flank for the process of grinding.
  
  
• Gear parts are sand blasted after carburising and quenching.
  
  
• Critical journals are ground finished and a setting datum placed for the setting of gear grinder. Finally the gear grinding process is preformed.
  
  
• Core Advantages of gear grinding
  
  
• Gear grinding process used gives the following core advantages besides others:
  
  

• Dimensional accuracy
  
  
• Improved part geometry
  
  
• Better surface quality
  
  

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.

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.

• External gear grinding
• Internal gear grinding
• On board dressing service
• On board inspection service
• Motorized dressers utilizing double diamond coated discs
• Quick dresser set up and wheel dressing times

Features of a Fine Grinding Machine

• Heavy-duty base
• Machining plate cooled by water
• Wrap-around steel worktable
• Provides parts handling
• Automatic digital cycle time
• High torque
• Speed plate drive that is variable