Jacobs Vehicle Systems®, manufacturer of heavy-duty diesel engine retarding systems and valve actuation mechanisms has launched its new High Power Density (HPD) Engine Brake to vehicle and engine OEMs in Europe. The company explains this provides large engine displacement retarding power in small and medium displacement natural gas and diesel engines.
The production-ready HPD Engine Brake realises one-and-a-half times the braking performance of traditional compression release braking over the engine’s entire operating range and more than two times the braking performance at lower rpm (the same retardation at 1400 rpm as at 2100 rpm previously). It delivers 2000 Nm of retarding torque at 1300 rpm and beyond and 611 kW power at 2500 rpm in a 13-litre engine. While delivering revolutionary braking performance, the HPD system is quiet in operation, being fully integrated into the customer engine’s overhead design.
The new brake was developed in response to the drive by global engine suppliers to provide higher levels of engine braking performance at lower engine speeds and improve thermal management to match industry trends such as down speeding and downsizing of engines, which are driven by the need for better fuel economy and lower total cost of ownership. Engine brake retarding performance is becoming increasingly important because key strategies for improving fuel efficiency are reducing the natural retarding of the vehicle caused by wind resistance, engine, drive train, and rolling resistance from the tyres.
Jacobs’ HPD Engine Brake transforms the four stroke engine into a two stroke compression device by deactivating the main intake and exhaust valve events and supplementing with two stroke valve events. Whereas a conventional engine brake has one compression release and one brake gas recirculation event per cam rotation, this patented two-stroke technology achieves two braking events per cam rotation. It is fully variable with controlled boost modulation, which allows the driver to achieve the right balance between retardation, speed and efficiency.
Another effect of market demand for improved fuel economy is the conversion of some fleet vehicles to natural gas engines, whose smaller turbochargers and lower compression ratios can diminish brake retarding power by up to 25 per cent. HPD compensates for this loss so that fleets can still haul standard load sizes safely.
“The majority of European trucks still use hydraulic driveline retarders, which are dependent on vehicle speed for effectiveness, and are typically 175 kg heavier, with a corresponding penalty for the vehicle’s payload capacity. The Jacobs HPD Engine Brake can cope with those lower speeds, eliminating the need for a driveline retarder and becoming the primary choice in secondary braking,” said Sergio Sgarbi, Jacobs Vehicle Systems president.
Because the engine brake uses standard, proven technology components, the company states it also offers a cost advantage. At a fraction of the price of hydraulic retarder devices it delivers in average a return on investment in six months compared to an average of two-and-a-half years for hydraulic retarder devices.
(Source: Propel Technology)