The word “big” takes on a whole new meaning when it is used to describe Caterpillar’s new 993K wheel loader. Built on an all-new platform, the 993K features Z-bar linkage, improved hydraulics, and an upgraded powertrain for solid penetration into the pile and high breakout forces—20% more than the 992G this vehicle replaces. According to Cat, the increased performance and capacity result in a 15 to 20% improvement in productivity compared to the 992G.
Designed to support key Cat off-highway trucks, the 50,000-lb (22,700-kg) loader capacity is four-pass matched to the Cat 777 and six-pass matched to the Cat 785. Because these trucks can represent a bottleneck for most projects, the 993K’s ability to load them in just four or six passes can help many jobsites achieve a new level of productivity.
Powering the new loader is Cat’s 12-cylinder, 32-L C32 diesel engine with ACERT technology. U.S. EPA Tier 2/EU Stage IIa compliant, the C32 delivers 708 kW (950 hp)—19% more power and a 5% increase in fuel efficiency as compared to the 3508B engine used in previous mining loaders.
Copper fins in the 993K’s next-generation modular radiator (NGMR) help to provide enhanced heat-exchange capacity. Design and construction of the NGMR minimizes the space required for the cooling package and allows enhanced sight lines to the rear.
Positive flow control (PFC) hydraulics, Cat’s next generation of load-sensing hydraulics, feature additional sensors at the pumps that are designed to provide enhanced responsiveness the operator can feel and use. The full-return-flow filtration system filters 100% of the implement oil return flow to 6 µm (236 µin) for extended component life and increased uptime. An optional deluxe filtration system prevents downstream contamination in case of a failure.
Cat’s electronically controlled planetary power shift transmission provides the 993K with 3F/3R speeds. An impeller clutch torque converter allows the operator to match rimpull to the application and underfoot conditions using a foot pedal combined with adjustments made through the rimpull-control system.
All-wheel drive features four planet-carrier gears with planetary double reduction in each wheel. Double-reduction final drives significantly reduce powertrain stresses and effectively extend powertrain life and durability.
Good visibility—a key safety component—has been engineered into the 993K with a redesigned, larger cab that is 2 ft (0.6 m) higher than in the previous model. For enhanced visibility, available options include a rear-vision camera with a cab-mounted display monitor, and rearview heated mirrors for inclement weather conditions. Accessibility enhancements include wider, 600-mm (24-in) side platforms, two side access points, and a ground-level switch to activate stairway access lights. Full-perimeter railing facilitates continuous availability for three-point contact, and an optional rear access system can be used to lift the operator to and from the cab.
For sustained operations, the new loader also incorporates features to enhance operator comfort, including a cab that is 14% larger than the previous model’s, a trainer seat, and seat-mounted controls that provide precise operation even on rough ground. Cab interior noise has been reduced to an operating level of 72 dB, and high-intensity-discharge lights are available as an option.
Wheel loaders this large often run on a 24/7 schedule, so to keep downtime to a minimum, the 993K incorporates a number of innovative solutions to ease maintenance and boost reliability. One example is Cat’s exclusive sleeve bearing pins, which eliminate the need for daily greasing of the front linkage. For lower life-cycle costs, the 993K is designed to meet mining-customer rebuild requirements and have an estimated 45,000-h structure life.
Ground-level service centers are lighted for nighttime access, and most machine lockouts are located in a rear-bumper service center. Standard and the optional deluxe service centers enable a technician to perform a variety of service procedures at ground level, and remote pressure ports aid diagnostics work.
The VIMS machine health monitoring system, equipped with an easy-to-navigate advisor display, records data for diagnostics and prognostics. Additional maintenance enhancements are also available.