There's little in the way of a wheel loader that hasn't been affected by the introduction of electronics.
"Electronics ? play an important role in the overall value of our machines and affect all aspects of machine operations," says Alan Pumklin, Caterpillar Inc. "They provide tremendous improvements in the areas of safety, operator comfort, productivity, reliability and dependability."
What started as basic advancements with Tier II engines has progressed to greater precision and control in units equipped with Tier III power plants. Further advancements are likely as Tier IV engines are introduced.
"As manufacturers move toward more electronically controlled machines, operation becomes simplified, owning and operating costs may be reduced and hitting production targets becomes easier and more consistent," notes Nick Tullo, Volvo Construction Equipment.
Electronics have affected loaders in three key areas:
1. They have enhanced machine performance by controlling the engine and transmission for benefits such as reduced emissions and smoother shifting.
2. They have allowed greater utilization of operator features that make it possible to match operator preferences to the machine and the application.
3. They have drastically changed maintenance and diagnostics to simplify daily tasks and minimize downtime and catastrophic failures.
In the area of performance, electronics make it possible to meet increasingly strict federal emissions standards because they automatically provide the right amount of fuel for a particular job. Consequently, the machine burns cleaner, yet maintains consistent power.
"Without electronics, we wouldn't be able to get such fine control over how much fuel is used," says Mike Gidaspow, Komatsu America. "Emissions are reduced and fuel economy is improved."
Engine efficiency is much better today because electronics have improved timing and regulation of fuel, valves, etc., adds Tullo. "To achieve low emissions in today's engines, all manufacturers rely heavily on electronics, although to reach Tier III emissions regulations, different manufacturers have different solutions."
Electronics allow manufacturers to custom tailor power torque curves for each machine to maximize fuel efficiency and provide flexibility in managing idle speeds for specific application requirements.
An example is the Engine Idle Management System that is standard on Caterpillar mid-sized loaders. "Four idle control speeds are available with this electronic feature," says Pumklin. "Combine this with our electronically controlled transmissions, and there is no doubt that most tasks performed by wheel loaders today are made possible by electronics."
Electronically controlled transmissions enable Caterpillar to offer features such as Variable Shift Control, which allows operators to select between three transmission shifting patterns to better match application requirements. Other features, such as the Automatic Differential Locking system available on the 938H/IT38H, continuously monitor the operation of the machine and aid in tractive effort to adapt to changing underfoot conditions.
Other manufacturers offer similar systems. For example, Komatsu's Variable Traction Control allows you to reduce tire slippage by adjusting the motor speed. "That helps save wear on the tires and it improves the control of the machine," says Gidaspow. "It makes it easier to operate and improves your productivity."
On John Deere models, electronics monitor speeds and loads. "With our transmissions - which are clutch-pack style - we can control oil flow and engagement adapting," says David O'Keeffe. "It makes adjustments based on the speeds and loads it sees on the machine. It allows for smoother shifting, gear wise and directionally."
Newer electronically controlled machines also feature proportional fan drives. "You need electronics to run the fans proportionally," O'Keeffe points out. "They sense system temperatures and only run the cooling fan drive as needed. The benefit is that if, for example, the fan only needs to run at 60% to provide needed cooling, the noise level is reduced and it doesn't pull extra power off the engine."