Cat's new excavator boasts host of hydraulic features

Caterpillar's new 325C LCR hydraulic excavator features a compact swing radius for high productivity in tight areas.

Caterpillar's new 325C LCR hydraulic excavator features a compact swing radius for high productivity in tight areas. The excavator rotates with a minimal amount of counterweight extending past the tracks, yet its power and weight enable the excavator to perform well in applications where space is not a factor.

Tail swing radius is only 6 ft 3 in. (1.90 m) — as compared to 10 ft ( 3.05 m) for the standard 325CL. The hydraulic swing drive turns at a maximum speed of 10.2 rpm with maximum torque of 82.2 kN-m (111,000 lb-ft) operating at pressure to 275 bar (3990 psi). The swing circuit is supplied by an 8-l (2.1-gal) reservoir. The machine uses an opencenter, two-pump, negative flow hydraulic system. High flow works within a hydraulic crosssensing system to boost productivity through faster implement speeds and quicker, stronger pivot turns. Pump flow decreases when controls are in neutral to reduce fuel consumption and noise.

The 325C LCR comes with standard combined function hydraulics, which allows users to choose from either 1-way or 2-way flow, using one pump or two. Flows can be set from a monitor, and flow and pressure settings for as many as five different tools can be stored in the monitor. This eliminates the need for tool adjustment when tools are changed. A medium pressure circuit is also available as an option for tools that require a rotate function. A hydraulic tool changer lets the operator switch tools without leaving the cab.

A hydrostatic drive can propel the 325C LCR at speeds to 4.3 km/hr (2.7 mph). The hydrostatic drive operates at pressure to 343 bar (4970 psig).

The main hydraulic reservoir holds 322 l (41 gal), and the entire hydraulic system requires 322 l (86 gal) of fluid. The hydraulic circuit for main implements also operates at pressure to 343 bar, and is capable of flow to 235 l/min (62.1 gpm). Pilot fluid at flow to 36 l/min (9.3 gpm) controls hydraulics at pressure to 41 bar (595 psi).

On the implement side, the 325C LCR's boom is actuated by a 140-mm (5.5-in.)bore, 1407-mm (55.4-in.) stroke double-acting cylinder. The stick cylinder has a bore of 150 mm ( 5.9 in.) and stroke of 1646 mm ( 64.8 in.), whereas the bucket cylinder has a 130-mm (5.1-in.) bore and 1156-mm (45.5-in.) stroke.

Snubbers are provided at the rod ends of cylinders, and both ends of the stick cylinder. The snubbers cushion shock that normally occurs when the piston approaches the end of stroke. The cushioning not only reduces noise, but increases cylinder life as well.