Alternative transmissions specialist Antonov is developing low cost transmission systems required for ultra low cost cars.
“We have unique experience of mechanical automatic shifting and alternative launch systems gained over almost 20 years,” said spokesman John Moore.
“Such systems are ideally suited to the development of low cost automatic gearboxes much needed for the low cost vehicles required for emerging markets.”
“Minimum cost can be achieved through the use of innovative technology and design and a careful review of the technical functions required.
“Above all the transmission must be simple, low cost, reliable and repairable. And if possible this means no pneumatic or hydraulic controls, minimal components and only the simplest of electrical systems.
“The transmission must also ensure ease of use for inexperienced drivers trying to cope with heavy traffic and be able to handle a wide range of vehicle payloads.
“The challenge today for the low cost car is to maintain only essential functionality,” added Moore.
Antonov’s basic automatic transmission concept uses its original patented shift system, which the company is also currently employing for a number of ancillary two-speed applications including alternators, superchargers and engine front-end pulleys – designed to make engines more energy-efficient and to facilitate the powertrain downsizing trend and increased electrical loads imposed on modern vehicles.
The shift system is implemented through a combination of centrifugal forces and the axial thrust from helical gears. The simplicity of the system is in its use of purely mechanical forces already present in meshing gears.
The principle can be extended to produce a simple low cost, yet highly robust and efficient three or four speed automatic transmission system, Antonov claimed.
It plans to simplify the gearbox with respect to launch and shift systems as well as considering the issues of powertrain and vehicle integration.
A range of alternative launch systems is being considered including a torque converter and various clutch systems including a centrifugal mechanism and stationary magnetic powder clutch.
“A low cost torque converter, for example, can be integrated with the engine to avoid the need for a separate transmission oil pump, circuit and cooler,” said chief engineer Simon Roberts.
“A torque converter provides an excellent launch mechanism for a vehicle and allows it to creep along in slow moving traffic – two essential requirements for emerging markets. Efficiency issues are mitigated by having a direct drive for high ratios and only taking the drive through the converter for low ratios.”
Antonov proposes the use of the simplest possible three or four speed systems depending on the application and precise requirements of each carmaker.
“Each gear can be selected by a mechanically applied band brake and the whole system is splash lubricated to eliminate the need for a pump,” added Roberts.
“The brakes across one-way clutches can be eliminated provided the vehicle has sufficient brake capacity to avoid the need for engine braking.
“Shift calibration can be maintained very simply by use of electric solenoids, which only require simple on/off control from a throttle switch and can replace hydraulic pistons.
“And, if required, we can dispense with electric solenoids and hydraulic pistons altogether and employ a purely mechanical means for shift control, making use of direct linkage from the throttle to alter the shift point.”
Antonov recently consolidated operations at Warwick, in central England, where it is also working on an electronically-controlled six-speed gearbox, the subject of on-going joint venture negotiations with Loncin in China, and a two-speed automatic mechanical module which is already in production as a self controlling mechanical drive for a dual-speed supercharger, with additional applications for engine front end accessory drives under development.