Gear shaping and hobbing are perhaps the two most common methods of gear creation. Gears are essential to the running of many machines, so creating the right gear is critical for smooth operations.
An Introduction to Gear Shaping
What is Gear Shaping?
Gear shaping is one of the most common methods of gear creation. Using the gear shaping method, gears are created using a machine to cut teeth into a piece of metal. A pinion shaped cutter rotates and reciprocates, creating the teeth.
The cutting can occur either at the upstroke or downstroke of the machine. During the creation process, the gear and cutter axes are parallel with the cutter rotating in motion with the gear blank. Both the cutter and the gear blank move at the same pitch-cycle velocity, with a train of gears producing the motion between the cutter and gear blank shafts.
When is Gear Shaping Used?
Gear shaping is generally known as a relatively simple and reliable gear production method. Gear shaping is also a convenient and versatile method of gear cutting. The gear shaping method is most often used to create internal gears and external gears, as well as integral gear pinion arrangements.
Gear shaping is also commonly used to create gears that will be located close to flanges or any other obtrusive surface in its destination machine. Because of the impressive accuracy of gear shaping, gears with low requirements for kinematic accuracy are often produced through gear shaping, without the need for further shaving or grinding of the gear.
What are the Advantages of Gear Shaping?
Gear shaping with a pinion shaped cutter, as described above, can be very cost-effective. The complexity of the mechanical gear shaper means the gear shaping produces a high level of accuracy in surface finish. If you need greater accuracy for your gear’s intended application, however, you can always finish your gear through another, more conventional process, such as grinding, honing, lapping, or shaving the gear.
An Introduction to Gear Hobbing
What is Gear Hobbing?
Like Gear shaping, gear hobbing is also a versatile and widely used process for gear creation. The process of gear hobbing requires a particular tool known as a gear hobbing machine, a kind of special milling equipment. Types of hobbing machines include the index hob and master hob. The hobbing machine can also cut splines and sprockets. The process of gear hobbing involves the use of an automated hob to cut teeth into a circular blank (or flat cylinder) piece of metal, or a “blank” gear. The hobbing machine works to cut the teeth as the gear blank rotates.
When is Gear Hobbing Used?
Most spur and helical gears are produced by the gear hobbing method. The versatility and productivity of gear hobbing make it a very popular gear production process. It is also used to cut splines and sprockets.
What are the Advantages of Gear Hobbing?
Gear hobbing is a flexible process, with particular flexibility afforded to the working angle. Many different types of gears can be produced with this method. It’s comparatively inexpensive, but it is pretty accurate as well.
What’s the Difference Between Gear Shaping and Gear Hobbing?
Which is More Accurate, Gear Shaping or Gear Hobbing?
As described above, gear shaping produces very high accuracy in surface finish. Gear hobbing, however, gives great movement accuracy. So, both have pros and cons depending on what kind of accuracy your gear needs. Overall, most experts would say gear shaping is more accurate than gear hobbing.
The transmission chain used in mechanical gear shaping is more complex than that of the gear hobbing process. The tooth profile error level of gear shaping is also lower than gear hobbing. With newer gear shaping machines, the transmission chain is greatly shortened, and transmission error is reduced greatly as a result. Gear shaping as a process is incredibly precise.
Which is More Efficient, Gear Shaping or Gear Hobbing?
Gear hobbing is generally regarded as being more productive, or efficient, when compared to gear shaping. The gear hobbing machine has fewer redundant movements, and can typically be a more cost-effective process, especially during the production of larger gears with fewer teeth, for example. Efficiency can be further improved by the addition of more gear blanks being stacked and cut at one time.
A notable exception to this general rule is that gear shaping may be more productive than gear hobbing when the required gear has a large number of gear teeth and a small tooth width. This is because the gear hob cuts using a high-speed rotating motion. The gear shaper is not as quick when it comes to cutting speed.
In creating gears with a module greater than 5 millimeters, gear hobbing is more productive than gear shaping. In creating gears with a module of fewer than 2.5 millimeters, the efficiency and accuracy of gear shaping are superior to that of gear hobbing. Finally, in the creation of gears with a module between 2.5 and 5 millimeters, gear shaping and gear hobbing are equally productive, or equally efficient
Illinois Pulley & Gear: Your Gear Experts
Illinois Pulley & Gear (IPG) is a custom pulley manufacturer with the goal of providing high-quality products in efficient and economic ways. Our primary products are Gears, Timing Belt Pulleys, and Timing Pulley Stock, and we create a wide range of gear and pulley stock for a slew of industries, including Aerospace, Agriculture, Automotive, Power Transmission, Automation, Robotics, Packaging & Labeling, Food Processing, Medical/Pharma, Wire Processing, 3D printers, Equipment, and Machine Components, and so much more!
At Illinois Pulley & Gear, we are passionate about producing high-quality timing belt pulley systems and gears that are built to last. Every timing belt pulley and gear is made-to-order to customer specifications, depending on your precise need.
We are client-oriented and ready to listen. To inquire about your business’ specific needs, reach out via our online contact form or give us a call at 847.407.9595.