Cat introduces its largest 300 family shovel to North America
Published in: Diesel Progress North American Edition
Date: 3/1/2004
By: Geske, Dawn M.
Caterpillar has introduced its largest 300 series front shovel to the North American market The 5090B front shovel is the latest addition to the Caterpillar shovel family and is designed to operate with trucks in the 40- to 70-ton classes for mining, aggregate and heavy construction applications.
The 5090B shovel has a bigger bucket, more horsepower and greater digging force than the 5080 shovel it replaces and Cat said that it expected 90% of the shovel’s application to be mining and quarry operations, with 10% in heavy construction. The machine is powered by a 15.8 L, Cat 3456 ATAAC diesel engine rated 513 hp at 1800 rpm. The engine adheres to EPA Tier 2, EU Stage 2 and MOC Step 2 emission regulations and has 20% more hp than its predecessor, Cat said. The shovel’s smoother engine operation and reduced noise emissions result from fewer internal engine components and rubber engine mounts, the company said.
The engine utilizes an air-to-air aftercooling system for higher power and lower emissions and the system is configured into a side-by-side layout for the radiator and oil cooler that in corporates two variable speed fan motors. The parallel design allows for maximum cooling and easier accessibility to the cores for maintenance and cleaning, tile company said.
The shovel uses a standard variable gauge undercarriage that is bolted to the carbody of the machine to enable it to be configured in a wide-track position for stable operation and a narrower 134 in. width for transport. Sixteen rollers guide the track, whose links am sealed to prevent dirt from entering and strutted for strength and impact resistance.
The machine’s tracks are held stationary by the internal disc brakes located in the two-speed axial piston motors. The two main variable piston pumps drive the motors in a closed center load sensing system that incorporates compact three-stage planetary reduction final drives. The final drives use added sealing to prevent dirt entry and oil loss.
The main pumps work in a three-pump system with an additional variable piston pump to control and give priority to the swing function of the shovel through the swing circuits. The open center Cat system uses two motors which each have a swing valve directly mounted to it. The main and swing pumps suction and discharge lines are larger in diameter for greater flow and higher efficiency, said the company.
The hydraulic pumps, control valve and hydraulic tank are located in close proximity to each other to minimize the length of” the piping for the on- demand flow system, Cat said.
The shovel’s dump circuit is controlled through a gear pump that works with the pump-valve controller to give commands to the bottom dump circuit. The implement consists of two boom cylinders, a stick cylinder, two bucket cylinders, two bottom cylinders and a master cylinder with parallelogram linkage that automatically keeps the bucket level to the ground.
The 201,900 lb. shovel reaches upwards of 407 in. and can dig to depths of 112 in. Six different bucket sizes ranging from 6.0 to 7.5 cu.yd, are available. The bucket has an SAE 1(15,210 lb. breakout force and is opened or closed through thumbwheel slide switches on each joystick or trigger buttons, one for open and one for close, located on both joysticks. This allows operators to configure the machine to their preferred method of bucket operation. The configurations are enabled via electronically controlled hydraulics.
The interior cab houses the electronic joysticks which control the level of gain/response and can be adjusted from quicker and more productive to slower and more precise, said the company.
Manufactured in Belgium, the 5090B shovel has been selling in international markets for the past year.
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