Modern Quarrying Q2 2019

The choice of a driveline is one of the principal influencers of a wheel loader’s efficiency on site

The hydrostatic driveline is more efficient in short cycle loading as the power losses are not as high as with a torque converter

A key benefit of the mechanical drive is the

The Continuously Variable Transmission is a combination of a hydrostatic driveline and mechanical transmission. It’s an efficient but complicated and expensive solution

provision of high end torque at the wheels and its simplicity to maintain

According to Schmitt, the powershift transmission is a proven technology with a very long life time. “The lock-up function eliminates the power losses from the torque converter. Intelligent shifting pattern – either selectable by the operator or sensed by the machines – makes the transmission adaptable to different applications,” he says. When it comes to the hydrostatic driveline, Schmitt says this is more efficient in short cycle loading as the power losses are not as high as with a torque converter. He, however, says that as most wheel loaders are used in load and carry applications – the hydrostat is very inefficient during these applications. Furthermore, the hydrostatic driveline generates a lot of heat and, therefore, requires a lot of cooling capacity. Another driveline option is the Continuously Variable Transmission (CVT). It is a combination of a hydrostatic driveline and mechanical transmission. “It’s an efficient but complicated and very expensive solution. The lifetime expectations are not suitable for a wheel loader and early overhauls are necessary,” explains Schmitt.

to have a purpose-built engine, transmission and axles that have minimal power losses without compromising the lifetime of the components,” says Schmitt. “Nevertheless, I would say that the biggest influence factor for efficient operation is the operator. Well trained operators don’t push the throttle to the bottom all the time; they know and have a feeling for how much power they need to fill the bucket quickly while avoiding spinning tyres. Modern technologies and automatic support systems, which you find on Volvo wheel loaders, will help even an inexperienced operator to achieve good results,” adds Schmitt. Types of drivelines According to McNeill, the Bell E series range of wheel loaders has a drivetrain that comprises of a John Deere POWERTECH engine that powers a ZF powershift transmis- sion which propels the machine through the John Deere Teammate V axles. A key benefit of the mechanical drive is the provision of high end torque at the wheels and its simplicity to maintain.

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QUARTER 2 - 2019 MODERN QUARRYING