18 AUTOMOTIVE DESIGN
➠
many innovative features within the transmission that Hyundai has applied for nearly 300 patents.
Hyundai’s Grandeur will be
the first vehicle to benefit from the new transaxle. In this application it will be coupled to a 3.3-litre V6 petrol engine and deliver a 12.2 per cent gain in fuel economy. In addition the transaxle gives a 2.5 per cent (0.2 s) reduction in the time to accelerate from zero to 100 km/h (62 mph) and an 11 per cent (0.5 s) improvement in the 60 to 100 km/h overtaking time. Despite the extra gear, the new transmission it is 12 kg lighter than the five-speed unit it replaces. It is also 41 mm shorter and considerably simpler, having 62 fewer parts, which is a key to increased durability and lower cost. The addition of a sixth gear enables closer spacing
demonstrated the key benefits of the Antonov six-speed design in its efficiency and ease of calibration. Within a few weeks of the first build, we have been able to demonstrate competitive shift quality and excellent efficiency. The prototypes have shown a 10 per cent fuel economy improvement over the
EU Urban cycle compared with the standard Aisin-equipped six-speed vehicles.” Another interesting development
from Antonov is a simple dual-speed drive to help alternators and other engine ancillaries operate more efficiently. Such drives can better match the speed of the ancillary to the
Fig. 8. Antonov Automotive Technologies is
developing a small six-speed automatic transmission for China’s fast-growing car market.
vehicle requirements and improve battery recharging. Antonov says the characteristics of its innovative duel-speed drive (known as the Antonov mechanical
between ratios, thereby providing a better balance of performance and fuel economy, while the wide overall gear ratio helps deliver strong acceleration. Inside, the gearbox has three planetary gear sets and an innovative flat torque converter that reduces the unit’s overall length by 12 mm.
Chinese imports
Hyundai is not alone in developing a six-speed automatic transmission; UK-based transmission technology specialist Antonov Automotive Technologies has completed the first phase of its agreement with Loncin for the development, manufacture and marketing of a small six-speed automatic transmission for China’s fast-growing car market (Fig. 8). Six-speed automatic transmissions are said to be much desired by Chinese consumers, but these currently have to be imported. Antonov says that all of the technical milestones for the first phase of the development have been achieved, including shift quality, drive comfort, NVH (noise, vibration and harshness) refinement, mechanical efficiency, fuel consumption,
Fig. 9. The Antonov mechanical module is a self-controlling, automatic, two-speed gearset that can be mated to an alternator to provide improved battery charging at engine idle.
manufacturing feasibility and the production of prototype transmissions for testing and development. Antonov’s chief executive
John Moore commented: “The prototype transmissions have
module or AMM) can be tuned to meet specific vehicle requirements. Essentially a self-controlling, automatic, two-speed gearset, the AMM can be mated to an alternator to provide improved battery charging at engine idle without incurring losses at higher engine speeds (Fig. 9). In this application, it can also provide a reduction drive to enable a compact front-mounted starter-alternator to be used for engine stop-start applications. The company, which is developing the system for OEM applications, says a dual-speed alternator designed for stop-start operation can deliver an 18 per cent saving of electrical energy over a typical light commercial vehicle duty cycle. The AMM can also be applied as a dual-pulley unit to
give a two-speed belt-driven alternator, air-conditioning pump and water pump, whereby the accumulated energy saving translates into a 5.6 per cent reduction in fuel consumption. This is achieved with a 2:1 gear ratio change at 2000 rpm. Ultimately the company aims to introduce a compact unit that is mounted directly to the engine crankshaft, but this will require much greater development integration with the base engine. Chris Baylis, the operations director at Antonov,
comments: “Customers and legislators are placing more demands on vehicle electrical power, with lower emissions meaning smaller petrol and diesel engines, lower engine idle speeds and more stop-start systems. Even daytime headlight legislation is increasing the electrical load.” Another application of the AMM device is to facilitate
low-cost engine downsizing by using it as a two-speed drive on a centrifugal supercharger. The resultant higher drive ratio at low engine speeds means that the smaller engine ‘feels’ bigger to the driver, allowing for less gear down-changing and improved fuel economy. n
www.engineerlive.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84