When it comes to grader productivity, what really matters is blade down pressure and blade pull force. The new G900B-Series generation of motorgraders from Volvo Construction Equipment has high blade down pressure due to optimal overall machine balance and the distribution of the main grader components. That’s not all: the new four-model range features new engines, rugged frames and sophisticated transmissions, according to the manufacturer.
The range consists of the 34,520 lb. (15,800 kg) G930B, the 35,843 lb. (16,400 kg) G940B, the 38,827 lb. (17,300 kg) G946B and the 38,709 lb. (17,550 kg) G960B. All models feature new, larger displacement engines with increased power and torque than the models they replace. Meeting the low emission requirements of Stage IIIB/Tier IVi legislation, these new units feature cooled exhaust gas recirculation (EGR) technology. This lowers the temperature in the combustion chamber and reduces the formation of nitrogen oxides by up to half.
Matched Performance
The increased and reshaped power and torque curves of the engines have been carefully matched to meet the needs of the transmission. Volvo’s eight forward gear/four reverse gear HTE840 or (optional) 11 forward/six reverse gear HTE1160 transmissions feature “shuttle shift”, a system that enables easy shifting between forward and reverse without the need to stop or use the inching pedal. Shift quality is computer controlled and transmissions provide a choice of auto shift modes and programmable target gears, allowing for optimal productivity and low fuel consumption.
Auto shifting (optional on the HTE 840) changes the gear in response to varying blade loads, resulting in less rework and longer transmission life. Smart shift and shuttle shift are fitted as standard, with smart shift recalling the last forward or reverse gear used. Shuttle shift allows quick direction changes, thereby reducing grader cycle times. Heavy duty inching clutches have been extensively tested. The optional HTE1160 transmission has more gears in a typical working range more slower gears for fine grading and more gears for fast travel, such as is needed in snow removal.
Traction Reaction
Traction is dependent upon the weight over the drive wheels and the ground surface. Too much power to the back wheels when there is a lack of traction results in wheel spin, tire wear and excess fuel usage.
The engines fitted to the G900B-Series feature three power curves with the 8X4 transmission and eight power curves with the 11X6 transmission to vary the power to match the level of traction available, and also optimizing the hydraulics and drive train.
To improve traction, the transmission is sited ahead of the articulation pivot point beneath the cab. This provides optimum weight distribution, assisting in blade down pressure at the front while at the same time weighing down the rear wheels and aiding drawbar pull values.
Traction is further improved by an operator-controlled hydraulic differential lock system that reduces rear axle strain and tire wear.
All wheel drive model G946B features two variable displacement pumps and direct drive wheel motors. The system is capable of providing 8,500 lb. (3,855 kg) of extra drawbar pull at the front wheels, especially useful when working in reduced traction conditions or in snow removal applications (where drive at the front wheels can offset the sideways effect of working on slippery conditions). The AWD system also allows for a “creep mode”, which allows the operator to grade using the hydrostatically-powered front wheel drive only. This can be desirable when performing fine grade work where the rear tandem wheels might damage the surface.
Twin Cylinder Circle Turn Mechanism
The latest generation of Volvo’s circle turn system features two pinions driven by twin direct acting hydraulic cylinders, which provide instant, high output torque. This enables moldboard rotation at any load, without the need to stop, reverse or change moldboard angle. The load is shared over more teeth for high strength, allowing long life and reliability of circle and drive pinion teeth, according to the manufacturer.
The operators have unobstructed lines of view to the moldboard, over the front frame, to the side and rear, allowing them to work more easily and safely. The spacious cab also features easy-to-use ergonomically designed controls, high performance climate control, a comfortable seat and familiar steering wheel.
These graders are fitted with industry-standard pattern controls, which feature low effort, low stroke levers and an adjustable pedestal, sited in front of the operator. Optional joystick controls are available, which have buttons or triggers for the control of all main attachments. Joysticks offer predictable and proportional response for hydraulic functions, articulation, (low speed) steering and transmission settings. A dual steering system allows steering via joystick (up to 18 mph or 20 kmh) or via traditional steering wheel. Operators also have clear access to the onboard Contronics monitoring system, which has been expanded to include more grader functions.
The optional lifetime warranty-protected rugged frame on the G900B-Series is designed to accommodate attachments that are supported entirely on the frame, and not braced or supported by power train components. Rear attachments, such as ripper, windrow eliminator or snow wings all bolt easily to the frame, which is rugged enough to withstand high shock loads, according to the manufacturer.
Centered on Service
Ease of servicing has been a major consideration of the new generation machines. Easy lift rear hood and side panels open wide for clear access to the engine and cooling module service points. Combined with extended oil change intervals and a need for only weekly greasing and the G900B-Series is ready for action. Swing-out radiator grill and (optional) automatically reversing cooling fan also makes cleaning cooling cores easy, as well as providing lower fan speeds, improving productivity and lowering fuel consumption.
The G900B-Series also is fitted as standard with CareTrack, Volvo’s telematics remote monitoring system. Caretrack provides information for better planning and smarter working; including fuel consumption, location and service reminders.
For more information, visit www.volvo.com.
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