Issue link: http://read.dmtmag.com/i/613635
I DA U N I V E R S A L N ove m b e r - D e ce m b e r 2 0 1 5 21 NUTS AND BOLTS NEWS At a recent media event, Kawasaki introduced a beefed up "XT" (stands for extreme) redesign of its two fl agship models, the 95Z7XT and the 115Z7XT, along- side the unveiling of two new loaders, the 90Z7 and 67Z7. Why more muscle? With the bigger buckets and heavier frames, the 95Z7XT and 115Z7XT now can carry roughly 12 tons per bucket. at means they can load a standard 24-ton truck in two passes instead of three. e 95Z7XT bucket size increased from 7.3 cubic yards to 9.0 cubic yards and is also available in a 9.8 cubic-yard confi guration. e 115Z7XT bucket size increased from 8.3 cubic yards to 9.15 cubic yards. To handle the extra weight in the buckets and ratchet up the breakout force, the boom arms were shortened and made thicker and stronger. is keeps the center of gravity closer to the base so as not to stress the front-end hydraulics and components. e hydraulic cylinder bore for the bucket cylinder was enlarged as well. Reinforcements to the chassis handle the additional torque and loads, and the counterweight was increased to balance the extra weight up front. Compared to previous models, the enhancements increased the breakout force by over two percent in the 95Z7XT, and six percent for the 115Z7XT. e 95Z7XT tipping load is 10 percent greater than the standard 95Z7, and the 115Z7XT is 15 percent greater than the standard 115Z7. Kawasaki also announced its fi rst Tier 4 Final wheel loader, the 90Z7. To meet exhaust emissions requirements, Kawasaki Introduces Power Upgrades in XT this machine uses selective catalytic reduction (SCR) and a diesel oxidation catalyst (DOC), but does not require the use of a diesel particulate fi lter (DPF). Manufacturers try to avoid DPFs, when possible, because they require regeneration to burn off soot that collects inside the fi lter. is process can be invisible to the operator, but may require you to temporarily cease work under certain conditions. DPF exhaust emission technology also tends to consume more fuel. But with the DPF-free design, the soot is burned up in-cylinder and these problems are avoided. Kawasaki used Isuzu engines on the Tier 4 Interim version of the 90Z7, but returned to their traditional supplier Cummins for the Tier 4 Final version. e new engine is a Cummins QSL9 that pumps out 275 net horse- power. Diesel exhaust fl uid (DEF) consumption for the Cummins mill is about four percent of fuel burned, and fuel effi ciency is up about fi ve percent, according to the company. e Tier 4 Final engines also have a better transient response than Tier 4 Interim, meaning the engine revs up quicker when you increase the throttle. e 90Z7 wheel loader got more than just a new power plant, though. A high effi ciency, 5.5 cubic-yard bucket design increases penetration and material retention. A fl ex-shi feature balances speed and rimpull to maintain tractive eff ort and improve cycle times. And a standard lock up torque converter in second, third and fourth gear helps conserve fuel and improve hill-climbing performance. Why the lock up? All torque converters lose some effi ciency due to the fact that they use a fl uid-to-fl uid coupling; basically like two fans spinning each other except they're moving hydraulic fl uid rather than air. is makes for smooth gear changes but at a steady speed without gear changes they're somewhat less effi cient than a purely mechan- ical, gear-to-gear coupling. e lockup function simply restores the mechanical connection whenever the speed and engine rpms reach a steady state. At their product press confer- ence, Kawasaki gave a demonstra- tion of the eff ectiveness of a lock up torque converter by staging a drag race between two identical wheel loaders, one with lock up and one without. In a run of about 200 yards, the loader with the lockup torque converter was roughly 80 yards ahead. When you need a burst of extra power, the 90Z7 off ers a temporary power boost function that can speed up cycle time whether you are using normal or power modes. ● www.equipmentworld.com, 11/10/15