Cat’s largest wheel loader—the 994H—applies 1,463 net hp (1,092 kW) of power and an operating weight of 431,000 lb (195,500 kg) to the task of loading large mining trucks up to the rated capacity of Cat’s 240-ton 793D.
Lift configurations for the 994H include standard, high lift, extended high lift and super high lift, providing dump clearances at maximum lift that range from 19.2 ft (5.6 m) to 23.3 ft (7.1 m). Bucket choices include heavy-duty rock, high-abrasion rock and coal—available in narrow and wide widths to suit the application—and ranging in capacity from 19.5 to 47 yd3 (15 to 36 m3).
The 994H is equipped with solid-steel lift arms that work though a Z-bar linkage that features a greased pin design and an automatic lubrication system. The 994H rear frame is a full-box-section fabrication designed to resist torsional shock and twisting forces, and the machine’s cast axle-pivot mounting areas disperse stress loads for added overall durability, according to Cat.
The loader’s Cat 3516B HD engine works through a planetary powershift transmission specifically designed for mining applications. An integral Impeller Clutch Torque Converter and Rimpull Control System allow the operator to adjust power at the wheels to specific loading conditions by modulating rimpull from 100% to 25%, reducing potential for tire slippage without diminishing hydraulic capacity.
The 994H’s Positive Flow Control (PFC) implement hydraulic system uses four electronically controlled, variable-displacement pumps, delivering up to 386 gpm (1,460 l/min) at a main relief pressure of 4,750 psi (32,800 kPa). The PFC system also integrates concurrent valve control, providing proportional command of loading functions with electro-hydraulic loader controls, electronically controlled cylinder stops and automatic kickouts set from the cab.
The Steering and Transmission Integrated Control System combines control of travel direction, steering and gear selection in a single controller, and the spacious, pressurized cab features automatic climate control and a quiet, 71 dB(A) sound rating. The 994H also features a powered access ladder and reduced stair angles for easy access and egress from the operator station. For enhanced operator awareness of the area around the loader, the Cat Detect Vision rear vision camera system is standard, and Cat Detect Object Detection is available. Object Detection includes radars that detect objects around the machine and notify the operator of these potential hazards.
Integral with the 994H Vital Information Management System (VIMS), which allows real-time assessment of machine performance, is a Payload Control System that enables on-the-go weighing, payload recordkeeping and analysis of parameters such as utilization, cycle time and fuel usage. www.cat.com