La nueva transmisión de doble embrague de McLaren: la más ligera y compacta de su clase

The McLaren MP4-12C’s new Sequential Shift Gearbox (SSG) is not only the lightest and most compact in its class; supplier Oerlikon Graziano says it also sets new standards for the refinement and durability of a Dual Clutch Transmission (DCT).

“McLaren has a very clear understanding of its brand and of the type of cars that it should make. This is reflected in the technologies and innovations that are chosen for their powertrains,” explains Oerlikon Graziano head of automotive transmissions Paolo Mantelli. “As well as being immensely fast and dynamically capable, the cars must be comfortable, refined, efficient and a pleasure to drive every day. We worked closely with McLaren Automotive’s engineers to develop a new transmission that would help them meet these targets.”



A DCT-type transmission was the natural choice as it combines smoothness and refinement with the possibility to change gear quickly with no torque interruption and therefore no reduction in acceleration. It also allowed a highly sophisticated control system, developed in conjunction with world-leading DCT controls specialist Vocis (a subsidiary of Oerlikon Graziano), whose UK-based team has managed some of the world’s most challenging and prestigious DCT programmes.

The compact dimensions were driven by McLaren’s desire to maximise passenger space without compromising dynamics. A three shaft architecture was chosen because the parallel secondary shafts help to minimise gearbox length, allowing the engine to be mounted further back. All eight ratios use Oerlikon Graziano’s high-performance synchronisers, further optimised to allow substantially faster changes without compromising durability.

“We wanted to achieve genuinely fast, smooth shifting without any of the ‘tricks’ that can be employed to make a DCT feel fast,” says Vocis managing director Mike Everitt, who’s team also calibrated the transmission.

“The secret is to get the very best out of the whole control system with a highly-optimised interaction between the software and the hardware. This ensures that the responses are not just quick and accurate but are also consistent and progressive. That means rigorous attention to the fluid dynamics and to the design and calibration of the control algorithms, which are constructed using our proprietary architecture.”


An unusual feature of the McLaren transmission is a ‘pre-cog’ facility that can make the already class-leading change time feel almost instantaneous. The driver can pull the gear up/down paddle to the first detent position, commanding the transmission to engage the next gear and preparing the oncoming clutch. When the paddle is pulled to the second detent, the gear shift is completed in a fraction of the time required by a conventional DCT. The system also makes the shift more engaging than typical DCTs with single-pull paddle shifts.

McLaren’s passion for weight reduction led to extremely sophisticated analysis of the transmission hardware with numerous iterations so that the maximum amount of material could be removed without compromising strength or stiffness. “McLaren set very high standards for durability too, so everything was tested in a virtual environment, then on purpose-designed rigs at our laboratories before whole-vehicle testing,” says Mantelli.

Rig testing was also used to validate the designs for the very high dynamic loads that the car can deliver. “At 1g, the oil will be at 45 degrees to the horizontal. The McLaren can significantly exceed 1g both cornering and accelerating and substantially exceed it under braking. Its dynamic performance is phenomenal, which makes managing oil flows critically important,” explains Oerlikon Graziano’s DCT programme manager Alberto Noto. “As the world’s leading supplier of transmissions for high-performance vehicles, Oerlikon Graziano has developed specialist test techniques that provide insights into these challenges and allow a high level of design refinement, helping us to improve performance and durability while also reducing weight.”

The very low weight is also important in reducing vehicle CO2 emissions, which were further cut by meticulous attention to the efficiency of the overall SSG system. Low friction bearings were specified and fluid thermal management was optimised. The result is a significant contribution to the vehicle’s ground-breaking CO2 performance.

The new transmission is manufactured at Oerlikon Graziano’s plant in Luserna, Italy, using a combination of precision automation and traditional craft skills to allow consistently high-quality manufacture in low volumes. Comprehensive end-of-line functional testing, using custom-built automated systems, ensures that every transmission delivered to McLaren meets their demanding requirements for Britain’s newest supercar.

Oerlikon Graziano has also recently started production of transmissions for the new Lamborghini Aventador and for the new Aston Martin Vantage S, each one using a different technology carefully matched to the character and technical requirements of the vehicles.

| Oerlikon Graziano

Volvo presenta su nuevo eje de transmisión que reduce el consumo de combustible

Volvo Trucks is now taking yet another step towards reducing its customers’ fuel costs by introducing a new rear axle for fast, heavy long-haul operations which could cut fuel consumption by up to two per cent, compared with today’s hub-reduction axles.

“Low fuel consumption is always a high-priority issue and for customers working in long-haul operations, whose vehicles may cover several hundred thousand kilometres a month, a reduction of a couple of per cent represents a major cost saving,” says Hayder Wokil, product manager for the long-haul segment at Volvo Trucks.


Intended for high engine power outputs
The new RSS1360 rear axle is a solo axle with single reduction designed for trucks with high engine power and gross combination weights of up to 60 tonnes. In other words, vehicles built for demanding long-haul duties carrying heavy loads and travelling at high average speeds. Food and agricultural produce are two typical cargoes for this application area.

Fast and fuel-optimised
This is a longed-for new feature, particularly among Volvo FH16 customers. For the first time they can now specify a solo axle without hub reduction, making it possible to cut fuel consumption by up to two per cent. The axle has a generous selection of ratios, making it possible to optimise the overall gearing in the best possible way. The RSS1360 can be specified for Volvo’s FH and FM ranges and is available on both rigids and tractor units. The new solo axle will be gradually introduced on various markets during 2011 and 2012, starting in June this year.

“The trend in Europe shows an increasing shift towards more powerful trucks and larger vehicle combinations. The introduction of the new rear axle is one of many measures from Volvo designed to show that fast and efficient transportation can also be very economical,” says Hayder Wokil.

| Volvo

BWI Group presenta su nuevo sistema de barras estabilizadoras: más pequeñas y ligeras

Global braking and chassis systems specialist BWI Group has developed a lightweight, more compact version of its proven Active Stabiliser Bar System (ASBS) that will make the many benefits of active roll control available to a far wider range of vehicles. Originally developed for large SUVs, the technology reduces the compromise between sharp handling and class-leading ride quality.

Advances in the systems’ actuators and optimisation of other components means it can meet the package constraints and weight targets of smaller cars, including sports cars and smaller SUVs. A comprehensive programme of system optimisation and advances in the actuators has reduced weight by around 15%. The company has developed a new rotary actuator that will go into production on an SUV in 2012, while a high-performance sports car with an active stabiliser bar system is due to start production later this year using BWI’s linear actuator.



“BWI Group’s range of active stabiliser bar systems now offers manufacturers even greater packaging freedom, making it easier to achieve the optimum installation,” said Olivier Raynauld, BWI Group’s manager, Forward Engineering Controlled Suspensions. “Our production experience has allowed us to scale down much of the original system for smaller vehicles that do not require the torque or extensive wheel travel of an off-roader or large SUV.”

BWI’s Active Stabiliser Bar splits the anti-roll bar in the middle and uses a computer-controlled actuator to apply variable levels of torque to the ends of each section. When cornering, the system applies an anti-roll torque, opposed to the lateral acceleration, which limits body roll. When subject to road disturbances, the system has the ability to apply a torque opposed to the one generated by the springs and dampers, thus limiting head-toss. This gives the benefits of stiff, large diameter bars without the normal compromise in comfort and refinement. It improves stability through corners by reducing roll angle and managing the tyre-to-road interface.

Because ASBS can deal with all the vehicle roll angle and roll velocity inputs, leaving the springs and dampers to deal just with vertical inputs, it helps eliminate the traditional compromise between ride and handling. The system is able to modify the understeer or oversteer behaviour of vehicles near-instantaneously. BWI supplies a range of linear and rotary actuators with single or twin channel operation, allowing the company to provide systems for a wide variety of applications said Raynauld.

“Our two-channel system allows vehicle manufacturers to adjust the front-rear balance in real time so that the understeer or oversteer characteristics are continuously optimised for the demands of each driving situation,” said Raynauld. “This helps produce a vehicle that manoeuvres better and remains stable at high speeds. Entering corners, the system adapts to help initiate the turn then resists overshoot as the vehicle exits.”

BWI supplies a wide range of chassis control technologies to vehicle manufacturers worldwide including electronic stability systems, variable damping systems and antilock braking systems. The acclaimed Range Rover Sport uses ASBS actuators and hydraulic control modules supplied by BWI.

First image: BWI’s Active Stabiliser Bar System allows an outstanding quality of ride combined with precise body control through corners. A new lightweight actuator provides greater torque density, making packaging of the system easier.

Second image: BWI has reduced the weight of its Active Stabiliser Bar System by 15%. The low mass and compact size allow OEMs to use the technology on smaller cars, including sports cars and smaller SUV’s.

| BWI

C-Innovation amplia su flota internacional de vehículos operados remotamente (VOR) con VORs de Schilling

Schilling Robotics, LLC, experts in subsea systems, announced today that C-Innovation has placed a contract for multiple ROV systems in support of their expanding international operations. This contract includes the supply of both HD™ and UHD™ work class ROV systems that will be deployed globally, including Brazil and Singapore.

This continued expansion of C-Innovation’s ROV fleet with a mix of the HD™ and UHD™ systems will broaden their regional capabilities and target markets, especially with the addition of the mid-size HD™ system that complements C-Innovation’s existing fleet of over 25 UHDs™.


“C-Innovation has rapidly developed a comprehensive ROV fleet in just a few years, and we are delighted that Schilling Robotics is able to provide the products and services that are required to support their international expansion,” says Tyler Schilling, chief executive officer for Schilling Robotics. Schilling additionally commented that “the market growth in regions such as Brazil and Singapore has resulted in Schilling partnering with FMC Technologies to offer dedicated, local support facilities and services that provide our customers with access to the same comprehensive level of resources available in mature regions.”

Ricardo Chagas, president of C-Innovation stated “the global deepwater market continues to be a focus for C-Innovation’s growth strategy, and we are delighted to continue with the expansion of our ROV fleet services by adding a versatile range of vehicle systems to meet our increasing customer requirements.” Chagas also stated “the global subsea industry will experience significant growth in upcoming years, and C-Innovation is prepared to support customer operations on a global basis with the world’s most modern fleet of vessels and ROVs.”

| Schilling Robotics