Just before the piston on a hydraulic hammer hits the tool it can be accelerating at a force level as high as 60 Gs, says Torsten Ahr, marketing manager, Atlas Copco Construction Tools. The goal in designing a breaker to survive in this environment, says Kevin Loomis, hydraulic applications manager, is to keep productivity high and increase the durability of the breaker. The company recently opened a new breaker repair facility in Austin, Texas, and also used the event to talk about how its technology achieves these goals and to introduce some new models and redesigns.
SB breakers get unitized body
Taking their cue from the Krupp technology used in larger Atlas Copco breakers (Atlas Copco bought Krupp Berco Bautechnik in 2002) the redesigned SB breakers have solid, single-piece cast alloy bodies rather than a three-piece assembly of head, cylinder housing and back head. The solid body eliminates tension bolts, reduces vibration and noise, cuts the number of parts by almost half and it’s lighter, Loomis says.
A field replaceable lower bushing in the new SB series greatly reduces downtime, and can be changed in 15 minutes at the jobsite rather than the hours of shop time required with older designs, Loomis says. The accumulator is cast as part of the body, and a new charge valve sits flush with the accumulator for added protection. This also eliminates the need to unbolt and recharge the accumulator when resealing the breaker.
Two new models were added to the SB lineup. These include the SB 100 and SB 150, for use on carriers in the 2,425- to 9,900-pound class.
Additions to middle and heavyweight breaker lines
A number of new models have been added to Atlas Copco’s PB, MB and HB series. The Penta series gained a new PB 530 breaker. Designed for use with skid steers, backhoes and compact excavators in the 9- to 15-metric ton-class, the new unit delivers up to 1,100 blows per minute and accepts hydraulic pressure up to 26.4 gallons per minute at 2,175 psi.
In the MB series, the MB700, with a service weight of 1,650 pounds, was added to the lineup and replaces the MB 800. It’s designed for foundation removal, secondary rock breaking and trenching, delivering up to 800 blows per minute with flows up to 32 gallons per minute at 2,465 psi. In the heavyweight category, the company unveiled the new HB 2500 for carriers in the 29- to 43-metric-ton class. The HB 2500 takes up to 58 gallons per minute hydraulic flow and delivers an impact rate of up to 550 blows per minute.
These medium and heavyweight breakers are also using an increasingly sophisticated array of technological solutions to boost productivity and reduce repairs and downtime. Here is an overview of those solutions:
- The VibroSilenced dampening system uses rugged, elastic elements between the percussion mechanism and the breaker box to dampen the sound of the breaker and the amount of vibration it transfers to the carrier. The company claims a 10- to 18-decibel reduction depending on the model. It’s used in the PB, MB and HB series.
- ContiLube II is a self priming automatic lubrication system mounted directly to the breaker. A 10,000 foot-pound breaker can hold eight tubes of grease, Loomis says, and many breakers can require greasing up to every two hours. Automatic lubrication eliminates this constant service chore, ensures rental outlets that their hammer’s getting sufficient grease and eliminates any unknowns about the status or proper procedures of greasing for rental customers, he says. It’s standard on larger MB models and all HB breakers.
- DustProtector. Dust driven up into the hydraulic breaker, especially the wear bushing area, can shorten the life of the breaker. Atlas Copco’s optional DustProtector prevents this with a reusable seal arrangement that contacts the tool at the base of the breaker. It’s offered on MB and HB breakers.
- AutoControl. To adapt the breaker’s frequency and power to the material at hand, the AutoControl monitoring system fires the first stroke at half power, creating a pilot hole to center the tool. It then adjusts the power output to match the hardness of the material to be broken. In soft material it lowers the impact energy and increases the impact frequency. In harder material it switches to high impact, low frequency hits. It’s standard on the MB and HB series.
- StartSelect enables the operator to tailor the start and stop modes to jobsite conditions. In AutoStop the breaker will not fire until the tip of the tool is pressing on the work piece. If the work piece falls away the breaker stops firing automatically, eliminating blank fires. The AutoStart mode limits by 50 percent the amount of power to the tool tip until the breaker is positioned securely enough to blast away at full power and allows the breaker to start operating as soon as it contacts the material to be broken. Start select is standard on the larger MB models and all models in the HB series.
- Energy recovery system. On extremely hard materials piston recoil may damage internal components or the carrier machine with pressure spikes. With energy recovery, a shuttle valve almost instantaneously detects the recoil and siphons off the hydraulic oil in a high-pressure accumulator. The stored energy is returned to the piston on succeeding strokes, making them harder and faster. You avoid the potential damage of a head-on collision of reflected energy between the tool and the piston, says Loomis, and redirect that energy toward more aggressive hitting. Energy recovery can boost percussive performance by 25 percent without increasing hydraulic input.
- PowerAdapt. Should the carrier machine send excessive hydraulic input to the breaker, PowerAdapt shuts down the breaker and returns it to normal function once the overflow situation is corrected, preventing damage to the breaker’s internal components. It’s standard on larger models in the HB series.
New service center
Atlas Copco’s new regional service center in Austin, Texas, will not only sell and service the company’s hydraulic breakers and attachments, it will service and repair other makes of breakers as well. In addition to its function as a sales, service and repair outlet for the southern and western United States, the Austin center will serve as a warehouse for parts, accessories and breakers for Atlas Copco dealers that don’t stock a lot of inventory.
According to Keith Becker, national service manager West, more than 90 percent of the repair work at the Texas service center is done on competitive units. This not only insures a steady stream of customers but also creates the potential for new customers down the road, he says. When servicing or repairing other brands of breakers, the Atlas Copco technicians will only use parts from those OEM suppliers, rather than will-fit parts that may not meet the most current specs.