Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/473140
Pay attention to aftertreatment Wheel loaders in this size class have engines from 141 to 271 horsepower. EPA emissions standards are different for engines up to 174 horsepower and engines of 174 to 751 horsepower. Flexibility in the laws allows some OEMs to continue offering Tier 4 Interim machines even though Tier 4 Final went into place for all engines effec- tive January 1. One result of this is that aftertreatment technologies vary. Because aftertreatment system types can affect operation and maintenance, it's important to understand the design and requirements of a specific system. OEMs have worked to minimize the impact of aftertreat- ment. Kawasaki, for example, uses a Cummins QSB6.7 in their 70Z7 loader (3.7 to 4.2 cubic yard). The engine is rated at net 168 horsepower. Cooled EGR and a variable geometry turbocharger control NOx and PM while a diesel oxidative catalyst (DOC) controls the soluble organic frac- tion of particulate matter. The DOC requires no servicing. "Our 70Z7 loaders have a maintenance-free, regenera- tion-free emission system," says Gary Bell, vice president and general manager, KCMA Corporation. "There is no need to perform periodic manual regenerations. There is no DPF and therefore no need to remove a DPF for periodic cleaning or exchange. With no DPF there is no need for diesel emissions fluid. The emissions control system of the 70Z7 requires virtually no maintenance." The loaders meet Tier 4 Interim regulations, and will be offered throughout 2015 and possibly into 2016, says Bell. Location, location, location Some features are the result of reconfiguring traditional layouts. On their 821F and 921F loaders, Case moved the cooling module from behind the engine bay to behind the cab. Bisson says this placement of the high-efficiency cooling cube reduces clean-out intervals and susceptibility to thermal events. John Deere relocated the hydraulic oil tank from behind the cab to the frame under the left-side ladder that leads to the cab. This was done to make room for the SCR hard- ware under the hood while preserving rearward visibility. With their CommandPlus cab in the 457 loader, JCB moved the A pillars to match the width of the rear of the cab, opening up a panoramic view to the front. The right side A pillar holds all switches and auxiliary controls while all main controls are seat mounted and move with the seat as it's adjusted. Doosan reconfigured the steering columns of loaders in this size class to give more room for operators' feet and legs. Joystick electric steering is an option that provides steering of the loader without using the steering wheel. This type of steering can reduce operator fatigue especially in repetitive applications like V or L pattern loading. Doo- san uses outboard planetary gears and outboard brakes to decentralize heat load for better thermal management. Mike Stark, Doosan's wheel loader specialist, points to the flexibility in spec'ing their loaders. "The DL220, DL250, DL300 and DL350 all have Z-bar linkages; the DL250 is also available as a toolcarrier with a parallel lift linkage. The DL250 and larger models are available as high-lift models with an additional 12 inches of dump height." On-board weighing systems In a production environment, payload weighing systems for loaders help increase productivity and efficiency, espe- cially where accurate truck loading and material tracking March 2015 | EquipmentWorld.com 26 machine matters | continued Case Case F Series wheel loaders use SCR but no DPF to im- prove fuel efficiency, reduce exhaust temperatures, minimize maintenance and eliminate downtime associated with regen- eration and servicing of DPFs. The cooling module is placed behind the cab, not at the back of the machine, to facilitate a low, sloping hood and improve operator visibility. Komatsu As with all Komatsu Tier 4 Interim machines, the WA380-7 comes standard with 3 years or 2,000 hours of Komatsu CARE covering all scheduled maintenance. Komatsu CARE also includes two complimentary Komatsu Diesel Par- ticulate Filter exchanges within the first 5 years. The WA380-7 features Komatsu SmartLoader Logic to match engine torque to demand, thereby saving fuel.