Gear machining can range from grinding to hobbing. Since hobbing generally has higher productivity, hobbing is more widely used in production than any other gear processing method. Next page Bumper Mold,Bumper Mould,Auto Bumper Mold,Bumper Molding For Cars Taizhou ANO MOULD CO.,LTD , https://www.ainomould.com
At present, technological trends that have led to improved efficiency and precision in gear cutting include:
(1) Advances in gear cutter technology (especially coating and matrix technology).
(2) Exploration of the optimization design of gear cutters.
(3) The gear cutting machine is more flexible, or can complete more machining operations in one setup.
When gear manufacturers struggle to meet stringent requirements for production capacity and machining accuracy, the question has become: “How high precision and repeatability can future gear cutting machines achieve?â€
With the advancement of tool coatings and substrates, dry cutting continues to thrive in the gear processing industry as a trend, increasing cutting speed and extending tool life without the use of cooling lubricants. At present, dry cutting has become the standard process for bevel gear machining; at the same time, the machining of parallel-shaft spur gears is gradually turning to dry cutting.
The carbide inserts used in bevel gear cutters significantly increase tool life by coating a thin hard coating. According to TJ Maiuri, application engineering manager at Gleason Corp., the use of TiAlN coatings is still quite common. At the same time, AlCrN coatings without Ti have now become an optional coating. Developed by Oerlikon Balzers AG under the trade name "Balinit Alcrona", the AlCrN coating has a hardness of up to HV0.053200, a coefficient of friction of 0.35 and, most importantly, a maximum operating temperature of 1100 °C.
Coating more surfaces of the tool also increases tool life. Grayson's Maiuri explains that strip blades used to machine bevel gears are usually coated only on the rake face. If a coating is also applied to the other surfaces (top and side) of the insert, the tool life can be increased by 50% without any other changes to the insert or process conditions.
The forming method of the hob for cutting the parallel shaft gear is different from the hob for cutting the bevel gear, and they are usually a cylinder having a plurality of rows of teeth thereon, and the shape thereof is similar to that of the scroll. This type of hob is usually made of high-speed steel (not cemented carbide) as a base material and uses an advanced coating. Many hob manufacturers use powder metallurgy high speed steel as the tool material, while others insist on using more traditional base materials.
As an example of technological advances in parallel shaft gear cutting tools, Mitsubishi Heavy Industries' machine tool division has introduced a new version of its Superdry gear hob. According to Ian Shearing, vice president of Mitsubishi Heavy Industries, the hob uses a high-speed steel substrate called Mitsubishi Mach 7 and a special coating for Mitsubishi Superdry. The Mach 7 substrate is a simple high speed steel alloy (not powder metallurgy high speed steel). “The Mach 7 is malleable and can withstand high chip loads,†Shearing said. “This is necessary for dry hobbing because larger chips can take the cutting heat away from the work area. Mach 7 can be used as the base material to avoid the problem of tool chipping, and the powder metallurgy high-speed steel matrix with high alloy content sometimes has tool chipping. Mach 7 will have crater wear before chipping, and this situation Has good predictability."