As gear transmission efficiency and meshing noise requirements become higher and higher, the grinding process is pushed to the limit.Automatic transmission with planetary gear transmission gear is more and more (currently reached 10 speed), the gear becomes more and more Smaller, and more and more production.Also in industrial gear applications, such as motor gears, is now widely used in many start-up systems, even in the home. Most of these applications, the gear, the diameter of less than 160 Mm, modulus less than 3.
Unfortunately, the pinion grinding time is shortened, but non-production time can not be significantly shortened, so the ratio of production and non-production time becomes worse.Especially for the planetary pinion, the current grinding time can be Reduced to 6-7 seconds, but non-production time, that is, up and down the workpiece time even 5 seconds, resulting in less than 50% utilization of machine tools.
In the last decade, there has been little improvement in the productivity of hardened toothed surfaces, particularly in worm wheel grinding, and grinding technology, tooling and application data have reached very high levels with little room for improvement in a short period of time.
Different gear mill manufacturers have recently introduced a number of new machines, however, these machines still follow the traditional concept.At present, most gear grinding machines are equipped with two workpiece spindles, to reduce non-production time, that is, a spindle in the grinding position , Through the 180 ° indexing, the other spindle to replace the workpiece, however, non-production time can not be reduced to less than 5 seconds.This is because in order to ensure the accuracy of rotation, hydraulic locking must be used.Therefore, the table rotation It is necessary to release the clamp-rotate-to determine the new position-to lock it in. It is impossible to design a faster method for this movement.
Sapp Turnsley's G160 gear shows a fantastic new design to solve this dilemma, and better optimizes both static and dynamic rigidity than conventional gear mills.
Instead of using the rotary table to carry the workpiece spindle, the new G160 divides the current radial feed X-axis into two skids (X1 and X2), one for each workpiece, avoiding the need for a rotary table And all the limitations associated with it.The two workpieces can move forwards and backwards without interference on their workplaces.The first time a gear grinding machine realizes that the work piece and the grinding wheel are synchronized in motion and the grinding wheel can be fully utilized. The good thing is that the grinding wheel can be repositioned to the second workpiece at the same time without any axis need to wait for the other CNC axis movement, all movements are synchronized.X-axis slide with high dynamic linear motor drive, Workpieces exchange reached a record 1.6 seconds, which includes the time to engage and reposition the grinding wheel synchronously to achieve this level without the addition of many machine tool components, but with this fantastic design concept.
The new Sampont Toothley G160 grinding machine completely broke through this limit, rather than strengthening the Y-axis, as it completely removed it, which not only solved the problem of insufficient Y-axis rigidity but also simplified the mechanism, Instead of the conventional 4 NC axes, the radial (X), axial (Z), rotation (A) and tangential (Y) axes are overlaid with only 3 NC axes (Y, Z, A) This design, which replaces the 4-axis overlay with a 3-axis overlay, is a huge breakthrough that can greatly increase the overall rigidity of the machine compared to conventional gear grinding machines, resulting in increased productivity and quality. Tangential movement along the axis of the grinding wheel, instead of a virtual tangential displacement resulting from the interlocking of the Z and Y axes of the machine, can be done very large and very strong since there are absolutely no space limitations for these two CNC axes And high rigidity.
This exceptionally patented concept of a machine tool leads to the best productivity on the market today, while real machine tools deliver even more advantages.
The machine does not need an additional CNC spindle for dressing the grinding wheel. The grinding wheel dresser is installed next to the work piece spindle of the X1 table so that high precision and high dynamic rigidity linear motors can be used to create very good grinding wheel profiles, Good gear. The machine can topographically modify the tooth surface for incredible high-quality results. The design of the wheel dresser on the same slide on the workpiece spindle completely eliminates thermal deformation of the machine and some others Bias troubled.
Into the machine
When developing the G160 grinding machine, great attention was paid to ergonomics, which greatly satisfied the needs of various aspects of operation, adjustment and service of the machine tool.
Change the grinding wheel becomes very convenient, the Y axis of the machine tool moves the grinding wheel very close to the protective door. In this way, the flange of the grinding wheel is in front of the operator so that the distance close to the grinding wheel is very short. Next to the operator's protective door.
When the spindle is in the blanking position, a second discharge gate is provided for easy access to the two workpiece spindles. In this position, it is very easy to change the clamp, the tailstock tip and adjust the meshing sensor. For different external loading and unloading systems, from simple swivel sliders to flexible manipulator systems, the double-claw system is used when the grinding cycle is 20 seconds without sacrificing machining time. As the grinding time is as short as 8 seconds , The scara work-piece exchange system inside the machine can still guarantee this beat.
In order to facilitate maintenance and repair, people have very easy access to all of the mechanical, hydraulic and electrical components, these components either outside the machine or in the protective door between the machine tool and the electrical cabinet maintenance channel all the internal The integrated motor and encoder have separate housings that are easy to turn on for maintenance, all of which make the machine still incredibly small on the machine.
Finally, the same design concept applies to the newly developed SG160, a patented, dry-type gear grinding machine in which the machining is divided into two steps, roughing and finishing, and the roughing is done with a scraper hob , The use of worm wheel finishing SG160 dry grinding machine, most of the grinding margin removed by hobbing, the benefits of processing heat will not be transmitted to the workpiece, while the subsequent worm wheel worn out a small amount of surplus The margin, the same does not produce the danger of burning the workpiece, so the achievement of all-dry grinding process.
The additional advantages of dry grinding are even more noticeable:
By eliminating the need for cooling oil, the machine removes all oil-related peripherals such as oil pumps, fuel tanks, filters, oil mist separators and many others, significantly reducing machine tool investment and costs.
Because there is no cooling tank, the machine's footprint is greatly reduced.
Greatly improved the health conditions of workers and the workshop environment.
In summary, the Italian company Sampstone Toothley showed its technological leadership in the field of gear grinding with the introduction of the G160 grinding machine and its sister model SG160 SKY GRIND Dry Gear Grinding Machine. The development of these new gear grinding machines, Addressing the issues discussed above can be challenging, but the very positive results back from their testing through partnerships with major car companies and industrial companies demonstrate that these ideas have been successful, To be accepted by the market.