A practical closed-loop solution for producing the highest quality skiving tools for EV manufacture
With the race to meet targets for electric vehicles (EVs) such as the International Energy Agency’s (IEA) Sustainable Development Scenario, which aims to reach 245 million EVs in stock, about 30% of the market share, by 2030; solutions for manufacturing challenges in this growing industry are required. According to the Global Electric Vehicle (EV) Outlook 2021 report, there were 10 million electric cars on the world’s roads at the end of 2020, following a decade of rapid growth. Electric car registrations increased by 41% in 2020, despite the pandemic-related worldwide downturn in car sales in which global car sales dropped 16%. Worldwide, about 370 electric car models were available in 2020, a 40% increase from 2019. 18 of the 20 largest Original Equipment Manufacturers (OEMs), such as the BMW and GM Groups, have committed to increasing the offer & sales of EVs.
Skiving is the most efficient process for manufacturing gears for EVs. Bringing new technology together, the GCX Linear now includes in-process measurement to improve the manufacturing process of skiving cutters significantly. Responding to the market demand, ANCA brings a complete solution for manufacturing and sharpening skiving cutters. The GCX Linear sets the new standard for producing the highest quality skiving tools in carbide and HSS. Its in-process measurement with the analogue probe provides an accurate closed-loop manufacturing process, an industry-first innovation.
Drive longer, drive quieter: taking gears from DIN 10 to DIN 6
45% of all gear production is for vehicle transmission. The rise of EVs is changing the requirements for the gear industry. Higher engine speeds of up to 20,000 rpm mean a higher gear ratio is required for efficiency. Using a planetary gear set, also known as the epicyclic gear train, the sun and planet gears are external gears assembled inside a ring gear. The external gears are produced by hobbing then grinding.
The internal ring gear is traditionally produced with shaping or broaching. However, shaping is slow, while broaching relies on cumbersome tooling. Another trend, driven by the more compact new transmission design in EVs, is multiple gears on one shaft that are very close to each other; due to the interference, the smaller ones on the shaft cannot be manufactured by hobbing.
EV’s noise emission is also a considerable concern. Gears for EVs need to meet even tighter tolerances – increased from DIN 10 to DIN 6 for internal gears. The gear industry sees hard skiving as a revolutionary process to produce the millions of gears needed for the new EVs. The GCX achieves tighter tolerances ensuring accurate gears that will address the challenges of longer life and reduce noise emissions.
Skiving is a continuous material removal process, combining the rolling motion and milling motion. While meshing with the gear as a pinion cutter, the cutter simultaneously travels along the gear’s axial direction. It is as efficient as hobbing, reportedly five to 10 times faster than shaping. Skiving forms shorter chips, skived gears show higher quality, with lower surface roughness. The most challenging solid carbide skiving cutters are needed in the hard skiving process after heat treatment.
Addressing the common challenges of skiving tool manufacturing
Challenge No. 1 – Complex geometry
GCX Linear comes with parameterised design software to calculate skiving cutter geometry directly from gear parameters, provide collision analysis and grinding simulation.
Challenge No. 2 – Tight tolerance
GCX Linear achieves DIN AA quality with a suite of breakthrough technologies based on ANCA’s flagship TX platform: MTC (Motor Temperature Control), AEMS (Acoustic Emission Monitoring System), high accuracy headstock, large envelope, LinX® linear motor on all linear axis and iBalance.
Challenge No. 3 – Measurement
GCX Linear is the only CNC grinding machine with the industry-first in-process measurement using an analogue probe.
Traditional Gear Measurement Machines (GMMs) don’t have the correct mathematical model for skiving cutters. The GCX in-process measurement solution removes the need for investment in a GMM.
Challenge No. 4 – Dressing diamond wheel into complex shape within micron tolerance
ANCA’s advanced software derives simplified grinding wheel form and enables direct skiving cutter path compensation.
AEMS monitors the dressing process of the grinding wheel with an intelligent machine-learning algorithm to minimise cost and improve efficiency.
Challenge No. 5 – Quality control
A complete closed-loop production: Grind – Measure – Compensate all inside the machine without the need to unclamp the skiving cutter.
Challenge No. 6 – Knowledge gap
ANCA offers comprehensive training programs to help the engineer/operator step into the exclusive gear cutting tool world.
Complete process knowledge helps customers to adapt the standard process to their environment.
The ability of the GCX Linear to evaluate the gear profile against the correct mathematical form is a significant leap forward for the industry. Together with direct compensation, the skiving cutter grinding on GCX Linear is an efficient, practical closed-loop solution.
To learn more about how the GCX Linear solves common EV manufacturing challenges and the industry-first in-process measurement solution, download your free whitepaper.
For more information, Website: www.anca.com
