Rock literally has been around forever. Breaking rock still is a work in progress. But the evolution of breaker technology over the years has made the task considerably easier. New and improved features of hydraulic-breaker attachments even have allowed some breakers to work in applications where they otherwise could not. These features directly influence a breaker's performance and longevity.

The different environments in which breakers must work present a variety of challenges. Noise-level regulations and the density of the material to be broken are just two of many potential issues. It isn't hard to imagine the noise generated by the constant hammering of a breaker against rock. There is no mute button to press when it comes to breaking. However, many breakers do have sound suppression systems that will lower sound emissions.

The design of the breaker housing will significantly affect noise output. For example, a box completely wrapped around the breaker's percussion mechanism will act as a muffler. Since openings must remain in the box for maintenance purposes, noise can be reduced further by adding rubber plugs or covers to these openings to seal off sound coming from inside. Another available features is polyurethane wear components, which prevent metal-to-metal contact between the breaker's power cell and box. This greatly reduces the vibrations inside the breaker.

When a large breaker is hammering away at rock in a quarry miles from civilization, the noise level may not always matter. But breaking applications often occur in public places, such as near schools and hospitals. Here, there may be restrictions on when the work can be performed based on the decibel rating or sound power level of the breaker.

As far as 75 yards, a breaker without sound suppression can still register a volume of at least 85 decibels (about the same as a loud vacuum cleaner or noisy restaurant). With advanced versions of sound suppression, the same noise level may be registered only 10 yards away, getting much quieter as the distance from the breaker increases. Having this ability to limit noise allows a breaker to work longer hours in more applications.

Even in cases where no noise restrictions exist, the reduced vibrations from the breaker add to the service life of the machine by reducing wear and tear. The lower volume and diminished vibration going back to the carrier eases the stress on the operator as well.

Not only can breakers produce a lot of noise, they also can generate an incredible amount of power. While many applications require a breaker's full available force, some situations need only a fraction of that power. Fortunately, technology that automatically manages the power output of the breaker is available.

Using too much power can cause serious wear and damage to a breaker's components. Breakers are designed so that the tool steel will stay pushed up inside the breaker as a shock wave is delivered through the tool and into the material being broken. If the full power of a heavy-duty breaker is delivered when it far exceeds what's needed in lighter material, the tool can actually fire out from the bottom of the breaker with every blow as it tries to penetrate deep into the material. This causes severe abuse to the tension bolts that hold sections of the breaker together as well as the tool retaining components.

This type of situation also can lead to a blank fire. A blank fire occurs when there is little or no resistance against the tool, but the breaker's internal mechanism still delivers a power blow. The tool has to reach a metal-to-metal stop to prevent it from coming out of the breaker, causing excessive wear.

Power-control technology prevents these problems by monitoring the density of the material being broken. For harder materials, it allows 100% of the energy the breaker is capable of producing to be delivered. For lighter material, the system regulates the breaker's output performance, limiting the machine to half power to reduce or eliminate the chance of a blank fire. Yet power management can impede the breaker from getting started in some applications. Therefore, start-sequence options have been developed to compliment power control. This allows an operator to control whether or not down pressure needs to be applied before the breaker begins to operate. This feature usually comes with two startup modes.

One mode is intended primarily for jobs on firm ground involving breakers that produce a lot of force. This mode prevents blank firing by requiring that the breaker's tool steel be in contact with solid material before it starts. This can be especially helpful where visibility is poor or nonexistent. In these cases the operator may not know exactly where contact with the material is being made.

There are some situations where unstable material must be broken and there isn't full contact pressure against the tool. A second mode in some start-sequence systems will allow the breaker to operate and start breaking lighter material without down-pressure against the tool. The power-control system comes back into play by limiting the breaker's output power to half of its potential. The power continues to be managed until there is enough contact pressure from the material to warrant the use of full power.

Another cause for concern arises when breaking in applications with particularly high dust loads. These situations usually require additional protection to keep debris from being ingested into the breaker through its lower bushing. This can easily happen when breaking in a horizontal or overhead position. The debris particles will stick to the grease that is lubricating the tool in that area. The combination of lubricant and aggregate forms an abrasive paste that can greatly accelerate wear.

One advancement in breaker design is a sealing system that prevents debris from entering the breaker. Not only does this keep abrasive and damaging material out of the breaker, it allows clean lubricant to remain in the lower bushing area longer. Without a system to protect against debris ingestion, lubricant is consumed more quickly and wear bushing life is reduced by as much as half. Furthermore, the percussion piston may have a much shorter life cycle without protection in dusty environments.

Although outside elements pose the greatest risk to a breaker's durability, the internal mechanisms must be protected as well. The very nature of the components of hydraulic breakers and what they do dictates that most breakers need consistent lubrication to function properly and avoid breakdowns. However, the methods of greasing a breaker can vary.

Some breakers require manual lubrication at set intervals, usually every two to four hours. The primary disadvantage of manual lubrication is that a breaker may run without lubricant for a short time until it's refilled, which can be very hard on the breaker's components. And because there are so many lubrication points on a breaker, stopping to apply grease also contributes to downtime.

Taking these drawbacks into account, technology was created to automatically lubricate breakers as they work. Automatic lubrication systems are sometimes mounted to the breaker's carrier. Lubricant is applied through a hose that runs down to the breaker attachment. A carrier-mounted system certainly is more efficient than manual lubrication. The downside is that if a breaker is frequently moved from one carrier to another, it would require a separate system for each machine to which the breaker is mounted.

A more recent development in automatic lubrication technology involves a system that is mounted to the breaker. In addition to taking the responsibility for greasing the breaker out of the operator's hands, a breaker-mounted, automatic lubrication system provides a constant and uniform supply of lubrication at the proper intervals.

As a machine is used for more and more hours, it is almost inevitable that a breaker will encounter a hard section of material that it isn't able to handle with its normal energy output. What happens in this instance is that the energy wave that goes through the tool steel is not powerful enough to split or chip the material to be broken. Instead, the shock wave bounces off of the material and the energy is reflected back up into the breaker. The breaker's piston then changes direction, causing it to back feed hydraulic oil in the breaker and create a spike in the system.

If the piston moves down to deliver a double hit at the same time a recoil wave moves up the tool steel, the resulting collision can amount to a far greater impact than the breaker's components were designed to withstand. Tools and pistons could conceivably break in this situation.

This problem has been addressed through technology that monitors piston movement and thus prevents it from bouncing or double hitting. While this does help prevent damage to the breaker, it doesn't necessarily help the operator finish the job of breaking the hard material.

Another feature implemented on some breakers is energy recovery. This involves the high-pressure accumulator, which essentially is a storage cell that momentarily collects the reflected energy coming back into the breaker. This energy, which is basically a volume of hydraulic oil, is then released during the next blow delivered by the breaker. Furthermore, the energy is released in addition to the breaker's normal power output. The combined energy effort can create performance increases of up to 25% in some cases. This boost in impact power may be enough to help break through the tough section of material that created the issue in the first place.

Because the breaker is recycling the energy from the initial bounce-back, it doesn't require any additional effort from the carrier. The adjustment occurs automatically as needed but otherwise is turned off. The system uses a potentially devastating situation to the breaker's advantage.

Kevin Loomis is a hydraulic attachments product specialist with Atlas Copco Construction Tools.

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