Breakers: Rugged, Reliable
- Published: Friday, 01 August 2008 08:00
When visiting a quarry or mine, one often hears the steady rap of a rock breaker operating somewhere on the pit floor, at the primary crusher station
When visiting a quarry or mine, one often hears the steady rap of a rock breaker operating somewhere on the pit floor, at the primary crusher station or elsewhere. The mechanical simplicity, flexibility and utility of these tools has made them an essential part of any quarry's mobile or stationary equipment lineup, so manufacturers keep expanding their product lines to meet growing customer needs.
Like other equipment in a quarrying operation, breakers operate in a rough environment and use an operating principle of blunt force. As a result, uptime and productivity are a high priority, and manufacturers are answering the call to make these machines more rugged and reliable.
Design and operating features such as vibration reduction, weight reduction and blank-fire prevention are incorporated into these units to keep them running and prevent repair and maintenance downtime. Manufacturers also are increasing the breaking force that these units provide, making things easier on crushing equipment downstream. Another innovation is the AutoControl monitoring system, which allows the breaker to adapt its frequency and power output to match operating conditions. The following roundup summarizes the latest features of this equipment.
NEW EQUIPMENT EMPHASIZES UPTIME AND FORCE
The MB 1500 hydraulic breaker attachment from Atlas Copco Construction Tools LLC joins four existing models to complete the company's medium-duty line of hydraulic breakers. The MB 1500 uses a combination of high single-blow energy and a high-impact frequency of up to 640 blows per minute. In addition, the new breaker was engineered with fewer components for reduced maintenance and longer service life.
At a service weight of 3,310 pounds, the MB 1500 is suitable for carriers in the 17- to 29-metric-ton weight class. Breaker accepts hydraulic input flow of 32 to 41 gallons per minute at operating pressures of 2,320 to 2,610 psi.
The unit includes an AutoControl monitoring system, which allows the breaker to adapt its frequency and power output to match operating conditions. It begins by firing the first stroke at half power to create a pilot notch that helps to center the working tool and prevent unnecessary tool slippage. It then adjusts the power output to match the density of the specified material to be broken. This reduces excess shock on both the breaker and carrier and lengthens the service life of tension bolts and retainer bars.
The MB 1500 also features the StartSelect system, which allows startup and shutoff to be adjusted to fit jobsite conditions. In AutoStop mode, the breaker will not fire until the operator applies down pressure on the working tool. AutoStop eliminates blank firing by circulating the hydraulic oil internally under low pressure when down pressure is not applied to the tool. This feature is designed to safely circulate and warm the hydraulic system before operation in cold climates.
In AutoStart mode, the StartSelect system works in conjunction with AutoControl. The breaker begins operating as soon as the working tool comes in contact with the material regardless of down pressure, but power is limited to 50% until the working tool can be fully seated in the breaker. This properly positions the breaker to accept full single-blow energy safely, without a damaging blank fire.
A VibroSilenced damping system and ContiLube II are additional standard features. The damping system helps to alleviate excess noise and vibration. ContiLube II is an automatic lubrication system mounted directly on the breaker. Featuring a compact, self-priming pump, ContiLube II eliminates the need to manually grease the breaker during each use, and lubricant levels can be continually observed and adjusted by the operator.
An optional DustProtector II system reduces maintenance concerns by helping to prevent dust penetration. Utilizing a reusable sleeve that contacts the working tool at the base of the breaker, the DustProtector II protects internal components from the damaging effects of dust. Attachment options include a flat chisel and a blunt tool.
The TB-XC Series of boxed housing breakers from Breaker Technology Inc. has new features in addition to its standard design of only two moving parts and no accumulators. A 20% narrower front head allows for trenching in more confined spaces. The series also offers a 10% reduction in weight and a suspended boxed housing design that reduces noise and vibration to the carrier.
The breaker body is suspended on all sides using compressed polyurethane isolators, absorbing and protecting the carrier boom from recoil energy, which prevents tie rod strain during blank firing. The breaker nose is surrounded with abrasion-resistant plating for long life. Front head support allows minimal movement, leaving the cylinder and gas-head free, without stressing the tie rods. A narrower profile on the XC models allows more visibility and better access when working in tight quarters. Breakers are available from the TB725XC (2,000-foot-pound class) up to the TB2580XC (13,500-foot-pound class).
Secondary breaking systems from Indeco N.A. are built from large welded-box-section structures with thick multi-plate fabrication in high-stress areas. The system consists of a mounted boom and stick, a hydraulic power supply unit and a heavy-duty hydraulic breaker designed to rake material, break material and keep product flowing.
The manufacturer points out that the units are built with many locally available spare parts, eliminating the need to order expensive, proprietary replacement parts. The company's booms are built with OEM, field-tested sealing components and fastened with self-aligning yoke-and-trunnion balls with shims for wear adjustment. This design eliminates the need to replace pins and bushings due to wear.
The manufacturer's Hydraulic Power Units are designed to be application-specific. A variety of electric motors, tank sizes, tank heaters, and manual and remote controls allows the company to tailor an installation to working conditions. Indeco's HP series working tool features variable speed and power, a design intended to provide the precise amount of power where and when needed. Large, welded-box-section structures are included to add structural steel to high-stress areas, reducing excess cost and weight.
In addition, an ìExcavator-Styleî curved boom design allows for a maximum working range. Heavy-duty cylinders assembled with self-aligning yoke-and-trunnion mountings are included for long life. Models are available with 170-degree swing or 330-degree rotation capability.
Sandvik offers boom systems for breaking large material. The L&XL-series is for applications that demand long reach and high breaking power. Features include a triangular boom structure, high twist capacity, heavy-duty cylinders, a round pedestal for even stress distribution and optional 360-degree swing. Four models are available: the L 850, L 940, XL 940 and XL 1200, which provide nominal horizontal reaches of 27.2, 30.2, 32.1 and 40 feet, respectively. Nominal vertical reaches are 22.6, 25.6, 30.2 and 34.8 feet, respectively. All of these models offer 170-degree swing.
The manufacturer also offers XM-series booms, which are designed for heavy-duty applications and feature modular design, interchangeability of parts, good spare parts handling, square tube construction and conical pin locking.
Models in this series include the XM 300, XM 500/HD, XM 600/HD, XM 700, XM 750/HD, XM 850 and XM 950. Nominal horizontal reaches range from 12.1 to 32.1 feet and nominal vertical reaches range from 9.2 to 19 feet. All models in the XM series also offer 170-degree swing.
Tramac has released the V2500 into its line of heavy-range hydraulic breakers. With an operating pressure of 2,248 psi (155 bar), the V2500 has a flow range of 46 to 66 gallons per minute. This hydraulic breaker is rated at an impact energy class of 8,000 foot-pounds and has an impact frequency range of 300 to 500 blows per minute.
Several new features have been incorporated into the V2500 design. These include a one-piece bushing and a large tool diameter of 6.3 inches (160 millimeters). The principal wear parts, including the bushing, are field-replaceable without dismounting the breaker from the carrier or removing any tie rods. Up to 2.5 gallons per minute (9.5 liters per minute) can be diverted through the integrated flow control to protect the breaker from carrier overflow. A high back-pressure tolerance of 363 pounds per square inch (25 bar) allows installation of the V2500 on a wide range of carriers.
The V2500 reduces the transfer of potentially damaging energy back to the carrier with variable-speed breaker technology. This technology senses changes in material hardness and automatically adjusts the breaker to the optimal combination of impact energy and striking rate.
A blank-fire protection feature that prevents metal-to-metal contact, which can damage a hammer, is designed to minimize maintenance on the manufacturer's heavy-range breaker line. An abrasion-resistant cradle protects the hammer and its internal components from damage and excessive wear.