At World of Asphalt here in Nashville, Volvo Construction Equipment has unveiled a double-drum compactor featuring a completely new design the company says will be its way forward in this segment.
The new DD105 is a 10-ton large asphalt compactor with a 66-inch wide drum. The machine will replace the DD110B and gains a new 3.8-liter Volvo Tier 4 Final engine, improved fuel economy, better visibility and a new pedestal design that makes it the first compactor Volvo will offer with an enclosed cab in North America.
Another major development for this machine is the new eccentric system, which has made near-instantaneous spin-up possible.
The new engine produces 114 horsepower and the machine weighs in at just over 22,000 pounds. The machine’s ECO mode has amounted to increased fuel economy of up to 30 percent in Volvo’s testing. In real world terms, that’s as much as two gallons saved per hour. Full specs are below.
Beyond an optional and plush, glass wrapped cab, with the DD105’s new design Volvo has decreased the footprint of its 10-ton roller while tapering the frame in order to enhance maneuverability and provide the operator with better sight lines to the drums.
The machine comes standard with an open canopy which slightly alters the design of the enclosed DD105 on display at World of Concrete. Volvo compaction product manager Mark Eckert says the canopy design moves the frame pillars at the rear of the cab inward, toward the operator in order to give an unobstructed view of the rear drum. On the cab version, that view is provided by small windows near the floor of the cab.
The machine’s engine is located in the rear frame and is easily accessible via a hood that slides up and back toward the back of the machine.
Volvo compaction product specialist Daniel Weaver says a big benefit to the new compact design is that it has much less weight hanging off its end. The primary benefit, however, is the machine’s curb clearance and its ability to work very close to walls or jersey barriers.
Further versatility comes thanks to the machine’s new pendulum joint joining the rear and front frames. “With this pendulum joint, the machine is inherently self-centering,” Weaver says. “When you turn the machine the joint lifts up slightly so as you let go of the steering wheel it tries to recenter. So the machine drives very straight on the road.”
And while the new design has brought several improvements, the transition Volvo engineers faced was not an easy one as pedestal designs have two drawbacks Volvo engineers sought to solve with the DD105.
“With a box frame,” which is still used on the company’s largest rollers, Weaver says, “because you’re fully encompassing the drum, it’s inherently stronger. Most other competitors have moved to this new design but the problem is their forces tend to come down.
“There’s a concern because this is a fork you’re only grabbing the drum around the outside and you need to make sure you do that correctly otherwise you have to tune down the forces of the drum to make it that way. In this case we’ve made it a point to not lower the forces of the drum so we took a little bit longer in designing the frame to make sure we have it set to be able to handle that.”
Weaver said the goal is to move more of its rollers in this new design direction.
Speaking of the drums, Volvo has implemented a brand new eccentric design that Eckert says is faster, more consistent and quieter.
“Every vibratory roller has an offset weight in there spinning and that’s where you get the vibration from. This design, we call it an optimized eccentric, because we basically made the weight inside as light as possible but we put the weight further from the center of rotation so that we get the same amount of force,” Eckert says.
“But because it’s lighter, smaller, we actually can spin it up much faster. What we’re talking about is less power needed from the engine, less of a power spike to spin that up. But now it does spin up in about a second as opposed to several seconds.”
Eckert and Weaver say the faster system provides operators with more consistent vibration by dramatically reducing dead time in the rollers whenever stopping to move into forward or reverse.
That means you’re going to have much more consistency in your vibration because you’re not going to have as much dead time with the rollers when you stop to move into forward or reverse.
Weaver adds that the new eccentric design increases operator comfort as well, decreasing noise and making the machine run smoother than predecessors.
“When it takes three or four seconds to spin up fully you’re basically running through the whole natural frequency of the machine, so once you do that you’ll pass the point where every time you start the machine the whole machine starts to shake a little bit,” Weaver explains. “But we’re passing through those zones much faster so it ends up feeling a lot smoother to the operator.”
The new design also features a spring dampener that eliminates the loud clanging sound that can occur when the eccentric is fired up.
The DD105 will be offered in two configurations: one with two amplitude settings for lift thickness and another with eight.
The two-amplitude configuration has a vibration frequency of 4,200 vpm on the low amplitude setting and a 3,200 vpm frequency on the high amplitude setting. “The eight configuration is useful because sometimes low amplitude is two low and sometimes high amplitude is too high for the particular lift you have,” Eckert says.
The drums also feature a hydraulic offset allowing one drum to be offset up to 6 inches (150 mm) from the other. Eckert says the offset is particularly useful while running the machine along a curb and when coming off a curb in a tight turn.
And thanks to the new pendulum joint, the offset has no effect on 38 degrees of the machine’s steering. “The joint tries to recenter and has the offset built into it and was built for scratch for this machine,” Weaver says. “In a lot of other machines if they do that you can’t turn as much either way.”
Water is supplied to the drums from a 211-gallon tank located beneath the operator’s station. The tank can be filled from the ground on either side of the machine.
Each drum is equipped with two spray bars, one of which is used as the primary sprayer while the other is a backup. The machine features dual diaphragm pumps as well.
“So, in one direction it’s going to use one pump and in the other direction it’s going to use the other pump. So they’re always coming on and off so we know that the backup pump hasn’t been sitting there for a year not being used,” Eckert says. “If one pump should fail, the other pump will take care of both spray bars.”
Inside and outside wipers are standard on the drums with a nice kick-down design on the inside wipers.