Impacting Breaker Longevity

Technology Aids Survival Of The Fittest
August 11, 2010

Rock has literally been around forever. Breaking rock is still 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 have even allowed some breakers to work in applications where they otherwise could not. In the survival of the fittest, hydraulic breakers last longer and can be used for more applications if equipped with the right technology.

Advances in technology have fundamentally set some breakers apart from the rest. The latest available features not only contribute to more efficient production on the job site, but they could also mean the difference between accomplishing the desired result and literally destroying the breaker itself. With so much at stake in demanding breaking applications, it is essential to consider the available technology that today's breakers have to offer.

Breakers are used in many different locations and applications, and therefore varying features of a breaker will be more or less important depending on the site. In many situations, the noise level of the breaker is a major concern. It isn't hard to imagine the noise generated by the constant hammering of a breaker against rock, concrete or any other hard material. 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 essentially 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. Other available features are polyurethane wear components, which prevent metal-to-metal contact between the breaker's power cell and box, greatly reducing the vibrations inside the breaker.

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

At distances 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 exact 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, but they can also generate an incredible amount of power. While many applications require a breaker's full available force, often situations will arise where only a fraction of that power is needed. Fortunately, technology that automatically manages the power output of the breaker is available.

Many contractors may feel that having more power is always the best policy. But 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 can also 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 result is that the tool actually 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 will allow 100 percent of the energy the breaker is capable of producing to be delivered. For lighter material, the system will regulate the breaker's output performance, limiting the machine to half power to reduce or eliminate the chance of a blank fire. The system simply saves a great deal of wear and tear on a breaker.

Finding a balance between breaking in firm or soft material is certainly a key factor in keeping a breaker in good condition. Another cause for concern arises when a breaker is used in applications with particularly high dust loads. These situations usually require additional protection to keep debris from being ingested into the breaker. This can easily happen when breaking in a horizontal or overhead position, such as during tunneling work.

A lot of the material that is being knocked loose may fly onto the breaker and get ingested through the lower bushing. This is problematic because 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.

An advancement in breaker design that counteracts this problem is a sealing system that prevents debris from entering the breaker. Not only does this stop the entry of abrasive and damaging material into the breaker, but it also 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. The same bushings can last twice as long or more if debris is sealed out.

Furthermore, the percussion piston may experience a shorter life cycle without protection in dusty environments. In fact, if enough abrasive material gets into the breaker, the piston's life may be dramatically shortened.

As a machine is used for more and more hours over its life cycle, it is almost inevitable that at some point a given 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 as a recoil wave is moving 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 type of problem has been addressed through technology that monitors the movement of the piston 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 feature takes advantage of the high-pressure accumulator, which is essentially 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 percent 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 requires no operator input. It occurs automatically as needed but otherwise is turned off. The system effectively takes a potentially devastating situation and instead uses it to the breaker's advantage.

Breakers need every advantage they can get in a world of breaking applications that is loaded with variables. Technology that will maximize a breaker's productivity and keep problems to a minimum is not a figment of an idealist's imagination. It does exist. Breakers lacking this technology simply run a heavy risk of failure, from excessive downtime to not even being able to work on the job in the first place. Meanwhile, in the demanding world of mining, tunneling, trenching, and demolition, the right technology is helping the fittest breakers to not only survive, but to continue to thrive for years to come.

         
 

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