Torotrak has acquired a 20-percent stake in flywheel hybrid innovator Flybrid Automotive Ltd (formerly Flybrid Systems LLP) with an option to acquire the remaining shares before the end of the calendar year.

While both companies are relatively unknown to the public, they are far from new on the hybrid scene. Together, they are involved in the Volvo V60 diesel-hybrid and in motorsport’s KERS energy recovery system, amongst other ventures.

Torotrak said the transaction strengthens the company’s ability to provide turnkey development and manufacture of complete flywheel hybrid systems for buses, trucks, passenger cars, commercial and off-highway vehicles. The company expects the deal will accelerate the adoption of its technology, which it says will be in fleet trials with bus operators later this year through an agreement with bus constructor Wrightbus.

Flybrid Automotive, a UK company owned by its founders Jon Hilton and Doug Cross, already has a successful long-term relationship with Torotrak, which uses Flybrid’s proven flywheel module in its Mechanical Kinetic Energy Recovery System (M-KERS).

Widely considered to be the world-leader in flywheel hybrid technologies, which can recover up to 70 percent of braking energy for around a third the cost of battery electric hybrids, Flybrid has evaluation or development programs with a wide range of vehicle manufacturers worldwide.

“As well as allowing us to accelerate the development of our M-KERS technology family, this acquisition will secure our access to what we believe is the most market-ready flywheel system available,” says Torotrak CEO, Jeremy Deering. “We now have the complete skill set, development resources and low-volume manufacturing expertise needed to help vehicle manufacturers, across a wide range of applications, introduce a technology that will allow them to significantly reduce CO2 emissions for a fraction of the cost and weight of conventional electric hybrids.”

Flybrid’s carbon fibre flywheel spins at up to 60,000 rpm in a near-perfect vacuum. Drive can be provided by the company’s CFT clutch-based transmission system or by Torotrak’s CVT (continuously variable transmission). Already proven in motorsport applications such as LMP1 sportscar racing, CFT KERS can provide up to 100 kilowatt and 540 kilojoule of storage in a system that has a full wet weight, including the electro-hydraulic control system, of less than 40 kilograms.

“CFT KERS scales down very well so could open-up a new market for small, low-cost automotive hybrids,” says Hilton. “It’s a good fit with Torotrak’s CVT, which is ideal for higher power systems and is already central to several of our customer programs.”

Flybrid’s portfolio of development programs includes Volvo Cars (which uses Torotrak’s CVT), Wrightbus, two manufacturers of off-highway vehicles and several motorsport constructors. Evaluation programs are ongoing with several other vehicle manufacturers across a wide range of sectors including passenger cars.

Flybrid said that if these relationships continue to progress as planned, their technology could be specified for a production vehicle by 2016.

Torotrak’s investment will provide additional resources to help secure this timing.

Deering sees these relationships as also offering considerable potential to extend the reach of Torotrak’s other technologies, particularly the company’s high-efficiency transmissions and low-cost, variable drive pressurecharging system. “Working more closely together allows a unified approach to customers and a strengthened ability to support them from development engineering through to supply of product,” he commented.

Strong Global Market Forecasts

Torotrak expects the first application of pure-mechanical flywheel hybrid technology will be in the urban commercial vehicle market, where benefits are strongest and volumes can be managed through existing relationships.

In the mid-sized UK bus market alone, there are 3,000 new vehicles each year and an existing fleet, with retrofit potential, of 50,000 vehicles. There are also substantial opportunities with other fleets that operate a stop-start drive cycle such as urban delivery vehicles and refuse vehicles.

In the passenger car sector, the Ricardo report forecasts penetration levels of 0.4 – 3.8 percent by 2020, offering potential volumes of up to four million units per year.

As well as affordable hybrids, these could include high-performance cars where the ability to release energy very quickly (quicker than batteries can allow) provides an attractive, differentiating ‘press to pass’ function.

Torotrak’s Jeremy Deering pointed out that the combination of the recent strengthening of the company’s high-precision manufacturing capability, together with joining forces with Flybrid’s own supply capability, means they can jointly support volumes from prototypes and fleet trials up to around 20,000 units a year, at which point the technology becomes attractive to global first tier partners: “We have the capability to work with vehicle manufacturers and Tier 1 suppliers from specific application development through to medium volume supply; our strong financial backing will help establish a strong first to market position.”