As is known to all, gear transmission is one of the most common in the modern machine mechanical transmission, is one of the important basic components of mechanical products. It with other forms of mechanical transmission, chain drive, belt transmission, hydraulic transmission, etc.), compared to drive with a large range of power, high transmission efficiency, transmission accuracy, long service life, etc. Many mechanical products as a result, it has become a indispensable driving part, is also accounted for the largest machine transmission form. 

Gear has been prominent in the position in industrial development, has been recognized as a symbol of industrialization. From this perspective, the network mould expressed concern about China advanced processing technology and development trend of gear has the extremely important significance. 

2 the new development of gear machining 

In general, the gear manufacturing process including material preparation, gear blank processing, teeth, tooth surface heat treatment and tooth surface finishing and so on five stages. Tooth profile machining and finish machining after heat treatment is the key to the gear manufacturing, also reflects the level of gear manufacturing. At present mainly from around the world gear processing technology and processing equipment for the development of the two aspects to constantly improve the level of gear manufacturing. 

2.1 hard tooth surface gear hobbing technology 

In traditional method, hard tooth surface gear processing need to pass the tooth surface grinding, due to grinding machining efficiency is too low, the processing cost is too high, especially for some large diameter, large module gears on the processing difficulty is greater, and USES the hard tooth face scraping as hardened gear (40 ~ 65 HRC) and a half, finishing is very effective. 

Hard tooth surface gear hobbing technology is also called skiving machining, using a special type of carbide hob, the tooth surface hardness after carburizing and quenching is HRC58-62 of the gear tooth surface scraping, scraping precision can be up to seven. This method can be processing any spiral Angle, 1 to 40 mm modulus gear. Average precision (6 ~ 7) hard tooth surface gear, generally USES "rolling, heat treatment, and scraping process, rough and finish machining on the same stage gear hobbing machine can complete; Higher gear tooth surface roughness requirements, can be arranged after scraping gear honing processing; Are used for high precision gear, rolling, heat treatment, scraping, grinding "process, with scraping semi-finishing replace coarse grinding process, removal of the heat treatment deformation of gear, leaving small and uniform fine grinding allowance, 1/2 ~ 5/6 of the grinding time can be saved and the economic benefit is remarkable. For big modulus, large diameter, width of the hardened gear, because there was no corresponding large gear grinding machine, normally only used for skiving machining. 

Using hard tooth surface gear hobbing technology for the gear processing, temperature control is very important, high temperature can make the tool wear speed and easy collapse knife, so need through the metal processing fluid to cool, at the same time washed away the chip on the cutter and workpiece, improve tool life and reduce the workpiece roughness of surface processing. Generally choose special oil-based cutting fluid for cooling and lubrication medium, such as KR - C20 gear hobbing gear shaper oil, through the proper control of the viscosity and excellent environmental and extreme pressure antiwear agent to satisfy the process of cooling, cleaning and lubrication requirements. 

2.2 the dry cutting technology 

Dry machining is no lubrication machining, is in the absence of cooling and lubricating agent, under the action of the high cutting speed in machining. High-speed dry cutting must choose the proper cutting condition. First, adopt the high cutting speed, shorten the contact time between cutter and workpiece, with compressed air or other similar method to remove the chip, to control the temperature of the working area. Practice has proved that when cutting parameter is set correctly, cutting the heat generated by the 80% can be taken away by chip. In order to further prolong tool life, improve the quality of workpiece, can be in the process of gear for dry cutting, using 10 ~ 1000 ml per hour lubricating oil with minimal quantities of lubricant. This method of chip can be thought of as dry cutting, the precision and surface quality of the workpiece and the internal stress is not affected by the negative impact of trace oil, can also use the automatic control equipment for process monitoring. 

2.3 the gear a chipless machining 

And gear hobbing, gear shaper, gear shaving and gear grinding and other traditional way of the forming of the gear, gear chipless machining method is to use the plastic deformation of the metal or powder sintering the gear tooth form part of the final forming or improve the quality of tooth surface. This method can be divided into the workpiece processed at room temperature and cold forming process the workpiece heated to 1000 ℃ of hot forming two kinds. The former include cold rolling, cold forging, etc., which includes hot rolling, precision die forging, powder metallurgy, etc., can make the material utilization from machining of 40 ~ 50% to 80 ~ 95%, productivity exponentially. But due to the mold intensity limit, at present only commonly processing module of the smaller gear or other toothed parts, high gear to precision request, after a chipless machining forming is still need to use cutting the finishing tooth profile. 

The development of 3 gear processing lubrication technology 

In recent years, due to the increase of the environment and resources pressure, appeared a variety of used to replace traditional in the field of cutting processing lubrication technology a new type of green cutting technology, such as non-lubricated dry cutting technology, minimal quantities of lubricant technology, low temperature air cooling cutting, etc., promoted the cutting technology, also to the structure of machine tool, cutting tool material, lubricating medium, etc. Put forward the new requirements.