Cat Welcomes New Litter of Compact Rubber-Track Models

Sun August 24, 2008 - National Edition
CEG



Three models of compact track loaders, the 279C, 289C and 299C, are the newest additions to the Caterpillar line of rubber-track loaders. The new loaders feature steel embedded track and steel undercarriage components for maximum life in aggressive applications. The new tracked machines deliver solid traction and reduced wear on sites with sticky, rocky soils, according to the manufacturer.

The new compact track loaders combine a freshly engineered suspension-type undercarriage, designed and built by Caterpillar, with the chassis of their multi terrain loader counterparts, the 277C, 287C and 297C. The fully suspended undercarriage employs four independent torsion axles for an enhanced ride and bucket load retention. Track-on-ground of almost 70 in. (178 cm) provides good flotation and traction, low ground pressure and long track life.

All three models feature two-speed drive systems, with a maximum speed of 8.5 mph (13.7 kmh), for fast movement around large sites. The electrohydraulic joystick control of the drive motors delivers straight-line tracking, and electronic torque management optimizes productivity. Drive motor seal guards extend the lives of seals and final drives.

The new models have rated operating capacities of 3,200, 3,850 and 4,150 lbs. (1,451, l,746 and 1,882 kg), at 50 percent of tipping load. Net horsepower ratings are 82 (61 kW) for the 279C and 289C, and 90 (67 kW) for the 299C. Lift-arm-path design is radial for the 279C and vertical for the 289C and 299C.

The new compact track loaders complement the Caterpillar multi terrain loaders, which feature very low ground pressure for high flotation and little ground disturbance. Multi terrain loaders also offer the best ride and highest travel speeds of all compact tracked machines. Now customers can choose the machine that best suits their primary applications.

New Undercarriage

At the heart of the Caterpillar compact track loader design is a robust new undercarriage. It uses an external-type sprocket, steel track rollers and idlers, conventional spring-type (grease-adjusted) recoil mechanism and rubber tracks that incorporate the reinforcing strength of steel — both as steel cords that run longitudinally through the tracks and as steel inserts at the sprocket-engagement points. The design emphasizes durability and aggressive traction, suiting it particularly well for applications in which maintenance, operator technique and underfoot conditions might present challenges.

In addition to its heavy-duty construction and heavy-duty performance, the compact track loader undercarriage also is designed to be easy on the operator and easy on the machine. Because the undercarriage is suspended via a pair of torsion axles on each side of the machine, each track assembly can flex independently, resulting in a softer ride for the operator, reduced shock loads through the machine and minimal spillage from the bucket in rough going. And with nearly 70 in. of track-on-ground, the 18-in. (46 cm) wide rubber tracks exert low ground pressures, while providing added traction and long service life.

Power Train and Hydraulics

Powering the three new loaders is the Cat C3.4T diesel engine, an inline, four-cylinder, turbocharged model with a 201-cu.-in. (3.3-L) displacement. The engine is designed with high-load-carrying bearings, induction-hardened cylinder liners, forged-steel/super-finished crankshaft, positive displacement gear-pump lubrication system and gear-driven coolant pump.

The engine powers a two-speed hydrostatic drive system, which provides a travel speed of 8.5 mph (13.6 kmh) in second range — and which is standard equipment for the new 279C, 289C and 299C models. The drive system is engineered to electronically balance torque and speed delivered to the tracks, a feature designed to promote optimum performance and fuel efficiency in any application, whether aggressively digging in a sticky clay bank, loading trucks or doing drawbar work. To complement the efficient design of the drive system, the drive motors incorporate Caterpillar’s seal guard, which helps protect the motors from damage.

Electronic control of the drive system allows continual fine-tuning of the engine, drive pumps and drive motors to deliver controlled tractive effort, but always in combination with ample hydraulic power for the implement (lift and tilt) and auxiliary circuits. Standard hydraulic flow is 22 gpm (84 Lpm), and rated system pressure is 3,335 psi (23,000 kPa). The auxiliary-hydraulic system uses a large variable-displacement load-sensing pump, provides a continuous-flow feature and incorporates heavy-duty, flat-faced quick disconnect couplings.

For applications requiring added hydraulic horsepower, Caterpillar offers the optional High Flow XPS auxiliary-hydraulic system, which delivers 33 gpm (125 Lpm) at a system pressure of 4,061 psi (28,000 kPa). The XPS system allows the new machines to efficiently handle such demanding work tools as a cold planer and a brush cutter.

A mechanical quick-coupler is standard equipment, and a hydraulically controlled coupler is available. For added control, the optional advanced machine information and control system (AMICS) allows the operator to select the level of loader-arm and bucket responsiveness, while also providing 10 work-speed selections.

Operator/Technician Amenities

To enhance controllability and ease of operation, the new models are equipped with a foot throttle, which allows the operator to adjust engine speed to suit the application, while also reducing sound levels and conserving fuel. This feature complements the independently adjustable joystick controllers, which are console-mounted to provide ample forearm support. The operator station is equipped with a suspension seat.

The optional enclosed ROPS cabin is sealed, pressurized and heated, with ventilation air filtered to eliminate dust. An available air-ride seat and air-conditioning further enhance the operator environment. The design positions the seat and surrounding enclosure to enhance visibility, and a quick-release door and safety interlock system prevent accidental machine movement.

Lift-arm safety braces are designed for easy use, and routine-maintenance features include a rear door that swings open 90 degrees to provide ready access to service points. Also, the cab tilts up for wide-open access to drive-system and hydraulic components.