Standard-Duty Rotary Breakers

Rotary Breakers are designed to simultaneously size ROM feeds while removing refuse from the feed. The standard-duty class of breakers is designed for feed material with lower percentages of rock and refuse.


Because less refuse is anticipated, the Standard-Duty Rotary Breaker design incorporates fewer cylinder beams with wider screen plates, a single discharge plow and lighter-duty dust housing.

While Rotary Breakers are often used to produce the final shippable product, in some cases they are used in applications as a primary crusher, scalping off rock and refuse and removing it from the downstream process, thus extending the life of the equipment and wear components.

Standard-Duty Rotary Breakers have been widely used in the mining industry for decades to process ROM coal, oil sands and cryolite. 

How Standard-Duty Rotary Breakers Work

The Rotary Breaker consists of a large rotating drum that is driven by an electric motor, gear reducer to a chain and segmented sprocket bolted to the cylinder. The cylinder is equipped with replaceable locomotive steel tires, which ride on a pair of trunnion rollers at each end of the cylinder. Thrust rollers are positioned at each end to prevent excessive axial float. When the Rotary Breaker is properly aligned, the drum will float between the thrust rollers, not ride hard to one side or the other.

Feed material is introduced at the front end of the cylinder and is continuously lifted and dropped onto a series of perforated breaker plates. This lifting and dropping action allows for the coal or similar types of feed material to fracture along naturally occurring cleavage lines, producing less fines and passing through the screen plate openings into the product chute. The harder material, such as rock and refuse, continues advancing through the drum until it is discharged onto the refuse belt or pile. Rotary Breakers require low horsepower per ton of material processed while cleaning and sizing simultaneously.

Why McLanahan Standard-Duty Rotary Breakers

McLanahan Corporation built the first Rotary Breaker in 1893, and since that time, our design is an evolution of more than 100 years of rotary equipment knowledge. Our overlapping screen plate design is bolted to the inside of the steel cylinder beams to further strengthen and add rigidity to the cylinder.

Designed to be durable, low-maintenance machines, Rotary Breakers are both safe and simple to operate. The low operating speed and horsepower requirement make Rotary Breakers economical to operate and easy to maintain. When maintenance is required, inspection doors in the fabricated steel and sectionalized dust housing, which covers the breaker cylinder, allow easy access, and the optional inching drive offers a safer means of rotating the cylinder. Centrally banked lubrication lines allow an operator to lubricate all bearings from one location.

All critical surfaces are machined during the manufacturing process in a single large lathe, producing a concentric drum that runs vibration free and extends the overall life of the equipment. This eliminates any chances of wobble or vibration during operation. Screen plates are offered to produce various product sizes and also in non-plugging designs, and are installed in an overlapping fashion to protect the cylinder beams and provide additional structural support. Chute work at the feed and discharge ends ensures a smooth transition of material in and out of the cylinder.

Frequently Asked Questions About Standard-Duty Rotary Breakers

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The operating costs are relatively low due to the rugged design, minimal downtime and low power consumption in comparison to other machines performing similar crushing applications.

Feeder-Breakers, single- and two-stage Roll Crushers and Mineral Sizers.

The ratio of reduction is quite high since the Rotary Breakers can except larger feed sizes while producing a small product size. This plays a role in selecting the drum diameter. The product size and tonnage requirement will also factor into the length of the Rotary Breaker required for the application.

The lifters in the drum play multiple roles. First, they lift and drop the feed material to initiate the breaking action. Second, they can be set in a neutral, advancing or retarding position. How the material is performing in the Rotary Breaker will determine in what position they are set.

McLanahan Standard-Duty Rotary Breakers are very reliable, durable and maintenance friendly.

Features & Benefits
  • All guarding is in accordance with MSHA and OSHA in the U.S. and can comply with other countries’ requirements
  • Drive sprockets and chain are completely encased in steel enclosure
  • Full-length base frame aids with installation and alignment
  • Adjustable lifters allow for advancing or retarding the flow of material
  • Renewable steel cylinder and trunnion tires
  • Cylinder end sections are manufactured out of heavy-duty fabricated steel construction and machined for concentricity to ensure smooth operation
  • End sections are joined by wide flange steel beams to form the cylinder frame
  • Perforated and overlapping screen plate design bolted to the inside of the steel beams to further strengthen and form the cylinder
  • Four independently adjustable trunnion rollers support the cylinder ends
  • The cylinder is driven by a chain and sprocket utilizing a motor/coupler/reducer drive configuration

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