The DD25 from Volvo Construction Equipment offers operators exceptional all-round visibility, thanks to a commanding seating position and an unobtrusive engine cover. Whether compacting forwards or in reverse, the drum edges are clearly visible – allowing precise compaction and increased safety. The ability to clearly see the work area reduces neck strain on the operator and avoids bumps and scrapes on the machine –improving safety for site personnel.
For a perfect mark-free mat
The 2,450 kg (5,400 lb) DD25 is a high frequency compactor that allows increased travel speeds while maintaining the correct impact spacing – resulting in a high quality, smooth finished asphalt surface. Depending on application, the frequency can be adjusted, from 3,300 vpm/55 Hz to 4,000 vpm/67 Hz. There are a number of applications that could require a change in frequency settings in order to maintain mat smoothness and density, ranging from site maneuverability to mix design and asphalt temperature. The frequency is altered by repositioning the engine throttle lever. Mat smoothness is also secured by an automatic vibration stop system, which eliminates the possibility of the operator forgetting to turn the vibration off and thereby damaging the asphalt surface.
The drums themselves are worthy of mention: they’re machined to be perfectly round, while the outer 20 mm (0.78 in) of the drum is chamfered and the edges are given a rounded 9 mm (0.35 in) radius profile. These features contribute to a smooth rolling finish that doesn’t mark the asphalt, meaning fewer passes are required for the perfect result. Both drums are fitted with wipers made of urethane for effective cleaning and longer life, even on abrasive surfaces. (Urethane has a higher cut-and-tear resistance than the more commonly used rubber.)
Both front and rear drums feature a pressurized water system that helps eliminate asphalt pick up and damage to the pavement surface. The rust-proof system provides a constant flow to the drum surfaces, and fine filters behind each of the spray nozzles minimize clogging and maintain proper ‘fan’ spray coverage to the drum surfaces. The brass nozzles and screens are designed for quick removal – without the use of tools – if a blockage does occur.
Water flow is maintained by a diaphragm pump and primary water filler. The spray is also adjustable, with the operator selecting the intervals between water sprays to the drum. Lengthening the time between spray activation (if appropriate) can considerably reduce unnecessary water use, and reduce time spent refilling the water reservoir. The water level can be easily monitored, thanks to a gauge mounted on the tank itself
Another major feature of the DD25 compactor is a new fuel efficient three-cylinder diesel engine which produces 24,8 kW. Thanks to a switch located in the seat, the machine will shut down the engine and apply the brakes should the operator get off the seat, maintaining safe operating conditions throughout.
Both drums feature maintenance-free eccentric bearings that are sealed and lubricated with lithium grease to tolerate higher temperatures and rotating speeds. All service points are easily accessible, thanks to a lightweight forward-tilting engine hood, which is supported by a pair of gas struts. Daily checks can be reached from ground level, helping ensure that maintenance is properly conducted. There is an easy-to-understand service chart on the engine hood, giving maintenance intervals and lubrication requirements. Servicing is made easy by grouped remote hydraulic and engine oil drain hoses housed in a side accessed compartment, making oil changes simple.
As with all Volvo products, the DD25 is backed by a supportive and knowledgeable dealer network. Supplying genuine parts, highly trained experts can provide a range of solutions to keep Volvo customers’ machines productively working and earning.