 Bobcat's 11.7-kW (15.7-hp) 322 has a mass of 1600 kg (3525 lb), making it the smallest member of the company's new D-Series compact excavators. The 20.3-kW (27.5-hp) 325 is the next largest, with a mass of 2790 kg (6145 lb). The 39.5-kW (53-hp) 337 is one of the largest of the D-Series, with a mass of 5010 kg (11,040 lb).  |
Bobcat Co. designed its latest generation of D-Series compact excavators with advanced instrumentation and hydraulic controls for improved serviceability and additional operator comfort. The new series includes the Bobcat 322, 325, 328, 331, 331E, 334, 337, and 341 models, with the small 11.7-kW (15.7-hp) 322 featuring an expandable undercarriage.
All D-Series compact excavators feature a swing-open tailgate for improved engine access and servicing. Made of heavy-duty, die-formed 6.4-mm (0.25-in) steel, the new tailgate eliminates the need for traditional cast counterweights. For routine maintenance, the fuel fill, control valve, and associated plumbing are accessible through a cover located on the right side of the excavator. The series also features centralized grease zerks for the swing pinion and bearing and offset cylinder. The zerks are located on the excavator's left-front corner for simplified servicing.
New piston-pump hydraulic systems improve engine power management and control of the work group, such as house swing, boom, dipper, and bucket functions. Bobcat claims the excavators have the highest bucket force and best cycle times in their classes, quoting the 322 with a breakout force of 15 kN (3410 lb) and a 9-kN (1970-lb) dipper force. D-Series models 325 through 341 feature an auxiliary function switch, located on the right joystick, which provides fingertip control of auxiliary functions. Bobcat claims it as the only auxiliary function switch in the industry to offer variable flow control built into the joystick. It also gives operators the ability of locked-on (detented) flow in both directions.
 For added safety, a control lockout is standard on the new excavators. Raising the left or right console locks out the joystick and travel functions. |
Instrumentation on the new excavators includes sweep gauges for engine temperature and fuel level as well as lighted icons to indicate machine functions and warnings. A new digital readout shows engine hours, rpms, and a resettable job clock. If the engine coolant temperature, oil pressure, or hydraulic oil temperature reach critical levels, the monitoring system will safely shut down the excavator to decrease chances of machine damage.
Engineers simplified the 322's hydraulic circuit for improved hydraulic line routing, and new spool metering advancements increase work-group function control. In addition, hose routing from the work group to the machine upper structure has been improved by adding a cast swing frame. Hoses are now routed through the lower portion of the casting. The casting also provides improved strength for the swing frame.
 All D-Series compact excavators feature a heavy-duty steel swing-open tailgate for enhanced engine access and servicing. |
To access job sites through narrow entries such as gates and doorways, the 322's undercarriage retracts and expands. Once at the digging site, the tracks can expand from 980 to 1360 mm (39 to 53 in), providing enhanced lifting and trenching, especially when working over the side of the excavator. Two 180 mm (7 in) backfill blade extensions provide extra width when the tracks are in the extended position. Bobcat engineers moved the two-speed function to the backfill blade handle to eliminate the need for operators to hold the two-speed in high range. Operators simply press the two-speed button once to put the excavator in a high range at about 2.9 km/h (1.8 mph), and press it again to shift the travel circuit back to low range at 1.5 km/h (1.0 mph). A light on the console indicates when the travel circuit is in high range.
The 322 also has an ISO/standard control pattern selection feature for rental yards and fleets, allowing operators to quickly switch between the control pattern with which they are most familiar. For added safety, a controls lockout is standard on the new excavators. Raising the left or right console locks out the joystick and travel functions, preventing inadvertent operation. An icon on the instrument panel indicates when the control console is down and the controls are active.
 The fuel fill, control valve, and associated plumbing are accessible through a cover located on the right side of the excavator. |
Two-piece, folding pedals control travel, auxiliary, and boom offset functions. When these functions are not needed, the rear portion of the pedals can be folded forward and locked stationary to provide additional foot room and an operator footrest. Boom- and frame-mounted work lights are standard with all D-Series loaders. Optional cab-mounted lights also are available.
