As transmission design grows more complex, the challenge for OEMs is to produce a greater range of gears in high volume while ensuring quality
Up until a few years ago, five-speed transmissions reigned supreme in automotive design, but gear numbers have grown rapidly in the last 10 years. With this change, 9- and 10-speed transmissions have become more common in the premium segment of the market. The additional gears allow the transmission ratios to be adapted more precisely to the speed of the engine, which allows the engine to run under optimal conditions. The result is lower fuel consumption, less heat build up and a smoother driving experience. All very welcome developments for the paying customer. For the manufacturers, however, this development means major production challenges.
A wide range of different gears need to be produced in their millions, while highest quality is maintained. EMAG handles this complex task by using one of the most compact solutions for gear manufacturing on the market.
The compact production line for gear manufacturing consists of just three machines, all from EMAG’s modular series, demonstrating the flexibility and performance capacity of this series. The newly introduced VL 3 DUO, a dual-spindle vertical turning machine, the VL 4 H, the vertical hobbing machine from EMAG Koepfer, and the chamfering and deburring machine VLC 100 RC are examples for EMAG’s manufacturing solutions which take up very little space and offer maximum performance. The TrackMotion automation solution (also from EMAG) demonstrates commitment to providing the best manufacturing systems from a single source.
The two work areas of the VL 3 DUO are each equipped with a 12-post tool turret
Modular machines – wide variety with uniform structureEMAG’s modular series are now in their fifth year of development and have experienced a considerable growth of various machine types since their introduction. In addition to the vertical pick-up turning centres for shaft and chucked parts, EMAG offers the entire range of chip-making machining techniques with this innovative machine solution: turning, milling, drilling, hobbing, deburring, grinding, hard turning, scroll-free turning, etc.
The basic structure of the machines always remains the same, with one common machine base made from low-vibration Mineralit polymer concrete, where the compound slide rest for the pick-up spindle is fastened. There is also an integrated parts storage unit, from which the spindle automatically loads and unloads itself, as well as a tool turret with 12 tool positions, or appropriate tool systems for the other manufacturing techniques. This has created a family of products that are perfectly coordinated and whose machines can be easily interlinked with TrackMotion to form complete production lines.Interlinking with TrackMotion automationThe TrackMotion automation system, presented for the first time at the EMO 2015 trade show, is the logical progression of the modular machine principle. The TrackMotion automation system works in a kind of symbiosis with the modular machines, with the individual components working together so perfectly that the interlinked production line is more like one single large machine than a system of separate machines plus automation.
The modular machines feature a “tunnel” directly behind the work area, made by separating off the energy container. A track is laid through this tunnel for an NC gripper, which transports the parts to their destinations. As each of the modular machines has its own pick-up automation system, the TrackMotion only transports the parts between the parts storage units in the individual machines. The gripper system also features a Z-axis, allowing the parts to be picked up and placed on stacker pallets.
This three-dimensional parts storage makes it possible to house an extremely high number of raw and finished parts (up to 400) in a very small space. This automation system also turns the parts over between the operations. The designers really have thought of everything.
Two spindles for maximum productivityThe modular machines are not only extremely versatile, but also extremely productive, as the technologies, the automation, and the timing are all coordinated perfectly. However, because sometimes even more is required, EMAG developed the VL 3 DUO in order to boost productivity even further. As the word DUO in the name suggests, it houses two full work areas in one machine, each complete with its own working spindle and EMAG’s proven tool turret. The machine is ideal for machining gear blanks for the manufacture of transmissions, a fact proven by its ability to handle parts up to a diameter of 150mm (5.9 in). When combined with the TrackMotion automation system and the parts storage unit with stacker pallets, fully automatic machining of both sides of a gear blank can be performed on just one machine in no time. Thanks to the pick-up automation system, there is virtually no idle time, and the 12-post tool turret provides enough room for twin tools, ensuring continuous operation and high availability.
Tooth cutting on a vertical hobbing machineAs soon as the gear blank is produced on the VL 3 DUO, it’s immediately transported to the VL 4 H hobbing machine from EMAG Koepfer. This company is the gear cutting specialist of the EMAG Group, and with the VL 4 H they have developed a hobbing machine that can be configured for a multitude of applications. The high-performance drives used in the working spindle and hob provide high speeds and torques to ensure fast, precise, and cost-optimised gear production. The machine allows dry hobbing of workpieces with diameters up to 200 mm (7.87 in) and module 4 – ideal for gear manufacturing. As is the case after every gear cutting operation, hobbing on the VL 4 H poses the question as to how the tooth profile can be chamfered with the highest contour accuracy. The vertical VLC 100 RC chamfering machine can be equipped with the relevant technology to suit every requirement, and completes the manufacturing line for gears perfectly.
This manufacturing system might look inconspicuous with its minimal footprint, but that just makes its huge output volumes and high machining quality even more impressive – a perfect union of modular machines and the TrackMotion automation system.