If “low spec” is the first thing that pops into your mind when you hear about a Chinese machine, LiuGong would like you to take a second look.
With the introduction of its new Tier 4 Final wheel loaders, the Chinese equipment manufacturer is bringing North American and European customers six of its most technologically sophisticated machines yet.
Designated as the H-Series, the Z-bar configured wheel loaders range in size from 3 to 9 tons and include standard features such as:
• Cummins or Perkins engines
• Rexroth piston pump
• Load-sensing, variable flow steering hydraulics
• ZF drivetrains
• Quick-coupler, third valve hydraulics (for the four smaller models)
• Ride control
• Rear-view camera
• High back, air ride seat from Grammer
• Topcon Tierra telematics
• Emergency steering
• Hydraulically actuated, on-demand cooling fan
The decision to use Cummins or Perkins engines was driven by the emissions regulations on engines in this horsepower class. These powerplants are well proven in the marketplace and familiar to American contractors, which will make service and repair easier says Hugo Chang, wheel loader product manager.
All these engines use diesel oxidation catalysts (DOCs) and selective catalytic reduction (SCR) systems that require diesel exhaust fluid. The largest model, the 890, also includes a diesel particulate filter (DPF).
The 835H and 840H models receive the Perkins 1204F engine. The 848H and 856H loaders get the Cummins QSB 6.7. The 877H is powered by the Cummins QSL 9, and the 890H gets the Cummins QSG 12.
Load sensing hydraulics
Perhaps the biggest change in terms of performance is the switch to closed-center, load-sensing hydraulics. “We are matching what the industry is doing,” says Chang. “This is a much more sophisticated, intelligent and modern system.”
In closed-center, load-sensing systems the hydraulics ramp up only on demand and proportional to demand. Heavy loads get high pressures and maximum flow. Lighter loads get less of both. This conserves fuel and pump life and helps the machine operate smoother. The sophisticated electronics which govern the load-sensing system also enable an on-demand cooling fan, thus further reducing fuel burn. In older, open-center hydraulic designs, the entire system is fully pressurized whether the machine is working hard or not.
LiuGong chose to continue using the ZF mechanical drivetrain it had on the older Tier 3 loaders. A hydrostatic transmission was considered, and prototypes built, but the final decision was to stick with the ZF mechanical system.
“Because we were changing so many things on this machine, we decided the one thing we wouldn’t change was the drivetrain,” Chang says. “We knew the ZF was a proven product and when it came down to a choice between improving the hydraulics or the drivetrain, we chose the hydraulics.”
The third-valve hydraulics on the new loaders was designed to activate a quick-coupler system. “Even if the loader is shipped with a pin-on bucket, we will ship it with the third valve deadheaded at the end of the boom,” says Chang. “The idea is to give our customers maximum versatility so later on, if they want to convert to a quick-coupler system, the hydraulic hosing and valve are already there for them.”
Since the 7- and 9-ton loaders are used primarily for production work and rarely change buckets, they did not get the third valve hydraulics.
Sound levels inside the H-Series cabs were also reduced due to European regulations, but benefit American customers as well. The 856 size machine, for example, went from 76 decibels to 73.