Boasting increased loading power and performance for a wide range of applications, Komatsu has introduced its WA250-6 wheel loader, which features a hydrostatic transmission system, variable traction control, improved operator comfort features, and the company’s latest Komtrax technology.
Replacing the WA250-5 wheel loader, the WA250-6 is powered by a six-cylinder, 6.7-L turbocharged Komatsu engine that is certified to U.S. EPA Tier 3 and EU Stage 3A, and delivers 138 net hp (103 kW) at 2000 rpm.
Komatsu’s hydrostatic transmission system (HST) allocates power according to demand, transmitting it hydraulically to a transfer case, then mechanically out to the differentials and the four driving wheels. The one-pump, two-motor system automatically adjusts to tractive effort demand to provide quick travel response and aggressive drive into the pile. The system features full auto-shifting, which eliminates gear shifting so the operator can focus on the primary tasks of digging and loading.
Both motors are fed by the HST’s single pump for tasks requiring high drive torque, such as digging, climbing, or initiating travel. The system responds to a reduction of torque demand, for example as a moving loader gains ground speed, by removing the low-speed motor from the drive system via a clutch; this reduces drag on the system as the flow goes only to the high-speed motor.
The HST system can also act as a dynamic brake on the mechanical drive system under conditions of deceleration, e.g. as the machine slows or completes a dig-and-lift operation. The dynamic brake can hold the loader in position on most workable slopes.
When traveling at a low speed, the machine’s tractive effort can be reduced with the traction control switch, which can help to reduce tire slippage, especially in wet or soft ground conditions. By helping to eliminate excessive bucket penetration and tire slippage during stockpile loading, the system helps to improve work efficiency and extend the life cycle of tires. Tractive effort can be temporarily increased back up to 100%, for example for aggressive penetration into the pile, with a maximum tractive switch that is located on the work equipment control lever.
For snow-covered or other slippery surfaces, a new S-mode control helps to provide optimum driving force at low speeds by controlling engine speed and the HST motor; this mode is only available for forward travel.
Breakout forces as high as 27,210 lb (121 kN) are available with the new WA250-6, as well as a static tipping load of 26,367 lb (11,960 kg) on the straight and 23,204 lb (10,525 kg) on a 40° turn. The new wheel loader’s operating mass ranges from 25,441 to 25,761 lb (11,540 to 11,685 kg), and it has a heaped bucket capacity ranging from 2.5 to 3.5 yd3 (1.9 to 2.7 m3).
Pressurized to suppress dust and reduce interior noise levels to below 70 dB(A), the WA250-6’s cab also employs Komatsu’s rollover/fallover protective structure viscous mounts to dampen noise, shock, and vibration, particularly in rough conditions. The loader’s low-noise engine, hydraulically driven fan, and hydraulic pumps are mounted with rubber cushions, and large, rear-hinged cab doors open fully for easier entry and exit.
Work equipment is operated from a new multifunction loader control lever that incorporates a forward/reverse switch and an adjustable wrist rest. From the right-side control panel, the operator can select the speed range, maximum travel speed in first gear, tractive effort, and reversible fan setting. The steering column, which incorporates an electronically controlled lever for directional changes, can also be tilted to accommodate operator position.
The WA250-6 is also equipped with Komatsu’s equipment management monitoring system, which monitors critical systems and alerts the operator when action is needed. The controller monitors key engine features, displaying any abnormalities on an LCD screen, and also tracks and stores abnormalities and error codes for future review and analysis. Komatsu’s latest-generation Komtrax system allows the loader to send a wide range of information to a secure website, including location data, error codes, cautions, maintenance items, fuel levels, and more.