Emission And Power Regulations, Ergonomics Spur Cat Loader Upgrade

During a phased roll out through mid 2006, Caterpillar Inc. is evolving G series medium wheel loaders to H series, whose models have engines complying

During a phased roll out through mid 2006, Caterpillar Inc. is evolving G series medium wheel loaders to H series, whose models have engines complying with forthcoming EPA regulations, plus new fuel saving and operator comfort features. The series launch has begun with the 950H and 962H models; the 938H, with capacity more suited to concrete batch plant and yard usage, will follow next year.

The H series models feature key changes to enhance productivity and reduce owning and operating costs, product engineers contend. New Cat engines featuring Acert technology Û the backbone of the company’s C9 and C11 models spec’ed for mixer and dump chassis Û provide increased power and meet U.S. EPA Tier 3 emissions guidelines. A new load sensing hydraulic implement system works more efficiently for improved fuel benefits of 4 to 7 percent and a 20 percent increase in lift force over the previous models.

Among company-cited operator and serviceability features new to the medium H series models are electro-hydraulic implement controls with simultaneous lift and tilt capabilities; 5-degree forward-inclined left access ladder; new cooling system; and centralized hydraulic and electric service centers for improved maintenance.

The new wheel loaders are designed to handle a wide range of tasks in construction. The 950H produces gross power of 216 hp (161 kW) and handles buckets of 3.3 to 4.6 cubic yards (2.5 to 3.5 cubic meters). The 962H produces gross power of 230 hp (172 kW) and uses buckets of 3.8 to 5.0 cubic yards (2.9 to 3.8 cubic meters).

ENGINE TECHNOLOGY

The loaders leverage the company’s Acert technology with the Cat C7 Engine. Acert is U.S. EPA Tier 3 compliant and provides what company engineers describe as advanced electronic control, precision fuel delivery, and refined air management for outstanding engine performance and durability.

The Cat C7 has 7.2 liters displacement. It is an inline 6-cylinder engine with mechanically actuated electronic fuel injection (MEUI). The system is comprised of four major components: injectors, a low-pressure fuel transfer pump, sensors to monitor speed, temperature and pressure, and an ADEM A4:E4V2 controller. The A4 controller is the brains behind engine responsiveness, self-diagnosis, emissions control and fuel economy. The system provides constant net horsepower through the operating range. Hence, a constant level of productivity is achieved regardless of parasitic loads, such as air conditioning.

For additional efficiencies, the 950H and 962H offer the new Engine Idle Management Software (EIMS), designed to improve fuel efficiency by enabling customers to change idle speeds to best suit the application. EIMS has four idle control settings: hibernate (fuel economy), work (set idle per application requirements), warm up (cold weather operations) and low voltage mode.

LOAD SENSORS

The proprietary Load Sensing Hydraulic Implement System is a closed loop device that automatically adjusts to operating conditions to provide only the hydraulic flow required by the implement. The result is optimum fuel efficiency, Caterpillar engineers note. Additional benefits are found with a new M3PC Priority Proportional Pressure Compensated Valve with integrated functions. The valve can set priority of one function over another and proportionally decrease or increase pressure on both the lift and tilt function to ensure no work stalls. With integrated functions on the M3PC valve, such as ride control and anti-drift, there are fewer line connections and less time required to retrofit.

OPERATOR PERFORMANCE

The H-Series electro-hydraulic implement controls feature soft detents. With electro-hydraulic controls and the new load sensing system, the operators can simultaneously lift and tilt the bucket. The result is better bucket control and less spillage.

The control levers are detented in the kickout positions (tilt back or dump). When the lever is moved into soft detent, the operator will feel an increased resistance from the lever. Once the lever is in the detent, the operator releases it and the bucket continues to dump or tilt back until it reaches the angle that is preset by the kickout. Kickouts are programmable from within the cab for easy changes when the height of the target changes. An optional electro-hydraulic joystick is available with the same functionality.

To ease operator access and egress, the loaders each have a redesigned left-side ladder, a self-cleaning model featuring a 5-degree forward incline. A full-length ladder is standard on the right side of the machine as well.

As with the GII Series, the 950H and 962H offer a choice of the standard steering wheel or the optional Command Control steering wheel. Turning the Command Control steering wheel about 70 degrees from the center point achieves full machine articulation. The system reduces operator effort in applications such as truck loading.

COOLING SYSTEM

An electronically controlled, hydraulically driven fan automatically changes speed to meet loader cooling requirements. The system saves fuel and reduces noise, while providing quick access for service. A new corrugated and perforated swing out rear grill minimizes entry of debris into the cooling cores and affords hydraulic oil cooler and air conditioner condenser access. Unit core joints are brazed for durability, while the standard, square wave unit core has six fins per inch for greater resistance to plugging and easier cleaning.

The 950H and 962H offer enhanced serviceability with a redesigned hood and counterweight and key changes to maintenance points. The new non-metallic hood is strengthened with robust reinforcing ribs and a new contour that adds rigidity. A one-piece counterweight is integrated into the machine design and styling, and the rear bumper counterweight incorporates the rear lights in the top structure.

For ease of maintenance, grease fittings have been grouped on the right side of the machine in two locations. An access panel below the right side service platform covers all the remote pressure ports for the steering, hydraulic system and brakes. A new hydraulic service center is located in a swing out door just below the right side access platform. It allows easy access to transmission oil and hydraulic filters. The hydraulic filter has a 500-hour service interval and the transmission filter has a 1000-hour interval for reduced maintenance costs. The H series models also provide ground level sight gauges for the transmission and hydraulic oil and radiator coolant.

Several new factory options allow equipping the loaders to meet specific needs. A new rearview camera is available. The windshield-cleaning package includes steps and handrails for ready access to the windshield. Another option, Caterpillar Autolube, lubricates pins and bushings while the machine is in operation. Other new factory options include next generation Product Link, which offers expanded options for more powerful equipment management. High intensity discharge lights and a high ambient cooling package also are available.
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