Better Grades

Volvo introduce B-series motor graders

Volvo Construction Equipment have introduced a new generation of B-series motor graders, one of which – the G746B – is said to be the most powerful all-wheel-drive grader currently available in the market.

Engineered to provide enhanced productivity, fuel efficiency, service access and operator control and comfort, the G700B-series line-up comprises five new tandem-drive models ranging in operating weight from 14,099kg to 19,783kg and in engine output from 105kW to 181kW (141hp to 243hp), together with two all-wheel-drive models with operating weights of 16,046kg and 16,639kg and engine outputs of 148kW (235hp) and 181kW (243hp) respectively.

More power

The motor graders are powered by Volvo 7.1-litre and 9.6-litre turbocharged, liquid-cooled, low-emission diesel engines featuring electronically controlled injection. All the engines are EU Step 2 and EPA Tier II compliant and were developed not only for optimum fuel efficiency, but also to provide high torque at low rev/min for precise power control at all speeds and in different grading applications. The engines are also well matched to Volvo’s proven 8400 transmission to deliver and sustain effective power under load and as loads change, while the extremely flat torque curve reduces the need for downshifting and simplifies operation, especially in fine grading.

All seven B-series motor graders are equipped with variable horsepower systems to ensure that the correct power is applied to the drive wheels in different applications.

Engine cooling is achieved by means of a hydraulically driven, thermostatically controlled, variable-speed fan that regulates fan speed depending on cooling demand to optimize power and further improve fuel economy.

The Volvo 8400 transmission has been well proven throughout several million operating hours. With eight forward and four reverse speeds, the fully sequential direct-drive system offers five speeds below 17.7km/h to cater for all grading operations, together with a high-speed road-maintenance gear, a snow-ploughing speed, and a gear for high-speed roading. In addition, the 8400 Smart Shifter provides rapid gear access through pulse shifting while ensuring that an appropriately matched forward or reverse gear is always available.

Improved hydraulics

The new machines feature a pressure- and flow-compensated hydraulic system for improved hydraulic response and reliability. At the heart of the new system is a 284 litres/min axial piston hydraulic pump which provides increased efficiency and optimum pump life, while a larger hydraulic reservoir ensures a continuous flow with minimum heat.

According to Volvo, the new motor graders can meet the most demanding requirements of fine grade contractors. By combining the high torque capability of the Volvo engines with a large variable-displacement hydraulic pump, the operator can reduce first gear ground speed by operating at lower rev/min while retaining full hydraulic control. This allows precise moldboard positioning to match the grade requirement.

More productivity

The new Volvo G700B-series graders also match transmission speeds and power-to-weight ratios to ensure maximum blade down pressure and blade pull. This is achieved by optimizing weight placement over the drive wheels and over a long blade base, thereby delivering more power to the ground and, in turn, faster cycle times and maximum job-site efficiency.

The drive system of the all-wheel-drive models is the equivalent of having three different drive systems in one grader. In six-wheel drive mode all six wheels are powered to grip the ground in poor conditions and add an extra 3,400kg (7,500 lb) more pull in front of the moldboard, making the machine suitable for clearing wet ditches and working on bank slopes. With the front drive disengaged the machine acts as highly efficient tandem-drive grader for operations such as top-of-road work or roading. The change from six-wheel drive to tandem drive is made with the simple flick of a switch.

The B-series graders can also be operated in ‘creep mode’ using the front wheels only, offering infinitely variable ground speed from 0 to 3.2km/h (0 to 2mph). Creep mode allows the moldboard to be pulled rather than pushed, giving the operator the ability to perform fine grading without scuffing the work behind the moldboard, even when negotiating a tight radius.

Other standard equipment on the new grader line-up includes lock/unlock final drives, four-wheel ‘cross-over’ oil disc brakes, fail-safe braking and spring-applied/hydraulic release park/emergency brakes.

Operator comfort

The ergonomically designed B-series grader cab includes a number of new features to help enhance operator comfort, convenience and efficiency. For example, the operator seat and control pedestal can be adjusted independently to conform to individual operator preferences, and all controls and gauges are conveniently located in a 90º arc in front and to the right of the operator for ease of access and comfort.

The nerve centre of the operator environment is the Contronic Monitoring System, which has been adapted from the system used on Volvo wheel loaders, dumptrucks and excavators. This multi-function facility informs the operator of the status of all machine parameters including engine rev/min and temperature, fuel level, ground speed, filter restriction, differential lock/unlock etc. The system also stores operational data for downloading by service technicians who can then use the VCADS Pro (Volvo Computer Aided Diagnostic System Professional) to access the information for maintenance and diagnostic purposes, and for performance analysis. This provides an opportunity for corrective action to be taken before a component failure takes place, as well as providing a diagnosis of the cause of a failure should one occur.

Improved servicing

Focusing specifically on ease of maintenance and long service intervals, the B-series’ design allows rapid and complete access to the engine compartment, cooling module and hydraulic area for cleaning, maintenance and servicing purposes.

The cooling module itself combines a thermostatically controlled hydraulic fan and a series of strategically located coolers wrapped around four sides of the module. The hydrostatic fan drive provides optimum cooling fan speed for any temperature, thereby saving fuel and limiting noise. In addition, the absence of ‘stacked’ cores in the B-series’ cooling system makes the system much less susceptible to fouling by dirt and debris.

The G746B all-wheel-drive grader

The most powerful machine in the new B-series motor grader line-up is the Volvo G746B. At 16,639kg in weight and with an 181kW (243hp) engine, the G746B is the highest-performance all-wheel drive motor grader in production today. Developing 13,730kg of blade pull for effective cutting and pushing performance, Volvo say the machine is well suited to road construction, road maintenance, ditch cutting, ditch cleaning, snow clearing and all other heavy-duty grader operations.

Volvo Construction Equipment Ltd, Duxford, Cambridge CB2 4QX; tel: (01223) 836636; fax: (01223) 832357; email: [email protected]; website: www.construction.volvo.co.uk