Xtrac Introduces Instantaneous Gearchange System

The motorsport transmission specialist Xtrac has applied its high performance engineering skills to design and develop a seamless gearchange known as IGS or Instantaneous Gearchange System. The race car technology, which is protected by worldwide patents, is now ready for commercial development in the automotive sectors. The innovative system avoids the cost, mass and complexity of a dual clutch transmission (DCT) and initial applications will focus on electric vehicles.

Xtrac, whose award-winning hi-tech factory is based at Thatcham in Berkshire, UK, with satellite motorsport operations in Indianapolis and North Carolina, is already heavily involved in developing advanced driveline technology for prototype electric and hybrid vehicles. The company says its latest innovation could help further improve the efficiency of electric vehicles as well as conventional powertrains.

A conventional gearbox has the disadvantage that it is necessary to interrupt the engine torque to change gear, which compromises vehicle performance. By providing a seamless gearchange the IGS mechanism enhances vehicle performance. The application of this latest motorsport technology to motorbikes, cars, trucks and buses would enable them to use less fuel and reduce CO2 emissions.

Details of Xtrac’s simple mechanical system are being revealed for the first time to the automotive industry at the International CTI Symposium and Exhibition being held in Berlin from 29 November to 2 December 2010. This annual forum regularly attracts high level engineers and senior executives seeking information about the latest technical developments in automotive transmissions. Adrian Moore, technical director at Xtrac, will explain the finer points of IGS in a detailed engineering presentation to transmission engineers from vehicle manufacturers and high volume Tier 1 suppliers.

“When introducing new technology to the automotive mainstream it’s important to have progressed beyond the initial research and development phase,” says Moore. “Car makers like to see practical demonstrations to show that the technology actually works and is more than a concept. With our motorsport experience we have the advantage of two years of racing IGS with professional teams.”

Moore’s presentation will explain how Xtrac has integrated a ratchet and pawl mechanism between each gear hub and the main shaft so that two consecutive gear ratios can be selected and engaged simultaneously, but with only one set of gears driving.

Xtrac has considerable experience in the design and manufacture of transmission systems for experimental, prototype, pre-production and specialist low volume vehicles, and a study is already underway to implement IGS into a two-speed EV transmission with the aim of ensuring the optimum performance of the vehicle.

“Whilst there is a phase of test and development and NVH refinement work to follow, we believe this is a suitable initial application,” says Moore, who is already pursuing feasibility studies with a number of vehicle manufacturers.

Credits: wilswong