The SHIFT 7k variant – with a torque range up to 8000 kNm – addresses the high-power, high-output onshore wind segments, as well as dedicated offshore markets. The SHIFT 3k variant covers the requirements for high-capacity factors in low- to very-low wind sites to boost annual energy production. Together with the SHIFT 4k and SHIFT 6k, the SHIFT platform is now able to maximize energy production at every wind site, notes the company.
In terms of torque density, the 3k and 7k designs in the SHIFT product family raise the bar in their respective segments, with the SHIFT 7k even surpassing the 200 Nm/kg mark. This torque density allows for lightweight platform gearboxes able to cope with a broad range of high torques, reducing the levelized cost of energy for wind power. Higher torque density means less material is needed to handle torque. Compact and lightweight gearbox designs play an increasingly important role in reducing nacelle weights as turbine tower heights continue to grow to boost customers’ annual energy production.
“Optimization of load sharing in these multi-planet stages is the “fine art” of gearbox design combined with selective assembly of components in the assembly process,” says Martin Knops, CTO of ZF Wind Power.
This important step-up in torque density has been made possible by ZF’s long-term R&D, continuously advancing gearbox design, components and materials. To achieve an overall ratio of 200, the SHIFT 7k variant has been designed with four stages in total, of which the first two have a higher number of planets in comparison with its 4k and 6k counterparts.
During its 40 years of activity in the wind market, ZF Wind Power has shipped 150 GW of high-end gearboxes worldwide, of which 75% of today’s shipments are based on the SHIFT modular platform design.
Photo: ZF Wind Power’s SHIFT 3k modular gearbox