Volvo unveils hybrid wheel loader

Volvo Construction Equipment (Volvo CE) unveiled a pre-production prototype of its L220F Hybrid wheel loader at the recent CONEXPO-CON/AGG exhibition in Las Vegas.

Offering more power, better performance and a 10 percent reduction in fuel consumption, the L220F Hybrid’s increased efficiency and cost saving potential will offer customers a much greater return on their investment over the lifecycle of the machine, the company states.

The Volvo L220F Hybrid’s parallel hybrid technology has been developed within the Volvo Group and uses as its platform the D12 engine. While much of the technology remains confidential, subject to patents pending, the heart of the hybrid system is an ISG — Integrated Starter Generator.

Fitted between the engine and the transmission, the ISG is coupled to a state-of-the-art battery that has many times the power capacity of a normal lead acid battery, according to Volvo.

The ISG works in a number of ways. First, up to 40 percent of a wheel loader’s time can be spent with the engine idling. The ISG allows the diesel engine to be turned off when stationary — and then almost instantly restarted by rapidly spinning the engine up to optimum working speed using a burst of energy from the high power battery.

Secondly, the ISG can also overcome diesel engine’s traditional problem of low torque at low engine speeds by automatically offering a massive electric torque "boost" — as the ISG’s electric motor offers torque of up to 700 Nm from standstill. Put in engine power terms, the ISG adds up to 50 kW of instant mechanical energy.

The combination of these two attributes of the ISG mean that the diesel engine will remain off for long periods when it would otherwise be idling — and that the operator does not need to over-rev the engine in order to get sufficient torque to work, as peak torque will be offered at almost tick-over engine speeds.

The battery is then replenished automatically without reducing productivity, with the ISG acting as a dynamo/alternator.

The company states the Volvo L220F Hybrid will be Volvo’s — and probably the industry’s — first commercially available wheel loader when deliveries begin in late 2009.

For more information, visit www.volvoconexpo.com.