Double-tooth Roll Crusher

Working Principle

The crusher is driven by two electric motors that transmit power through reduction gears to rotate two toothed rollers in opposite directions. When material enters the crushing chamber through the feed inlet, the two toothed rollers, equipped with helical teeth, first screen the material; particles that meet the size requirements pass between the teeth and fall into the discharge chute. Larger pieces of material are broken down by the splitting, shearing, and tensile forces exerted by the roller teeth and are discharged through the outlet.

The double-roller crusher employs a dual-roller crushing mechanism in which shear forces are directly applied to the rock material, generating substantial crushing forces along the material’s weak and brittle zones. This approach fully exploits the fact that the material’s shear and flexural strengths are significantly lower than its compressive strength, thereby reducing the energy consumption of the crushing process.

In addition to the rational overall structural design and appropriate crushing mechanism, the performance of a double-roller crusher is critically dependent on the geometry and arrangement of the crushing teeth. A well-designed tooth profile and optimal tooth arrangement can ensure the desired product particle size, optimize the particle-size distribution, reduce over-crushing, conserve material, extend the service life of the teeth, and lower the crusher’s specific power consumption. In this double-roller crusher, the crushing rollers are equipped axially with 8 to 15 integrally cast, quenched alloy-steel tooth rings; the tooth geometry and dimensions are specifically engineered in accordance with the principles of shear action, featuring large, specially shaped teeth. The large teeth on each ring are arranged in an axial helical pattern, while comb-shaped screening plates are mounted on the side walls of the housing to remove material that becomes trapped or adheres between the teeth, thereby preventing material jamming and blockage, and enhancing operational efficiency.

Structural Features

This crusher is primarily composed of an electric motor, a torque-limiting hydraulic coupling, a reducer, toothed rollers, and a machine frame, among other components.

(1) Torque-limiting hydraulic coupling

The torque-limiting hydraulic coupling is used to connect the electric motor and the reducer, reducing impact and vibration during startup while providing overload protection.

(2) Toothed Roll

The toothed rollers are the critical components for direct material crushing, with the teeth arranged in a helical pattern. As the two counter-rotating rollers mesh, smaller pieces of material are screened out, while larger chunks are crushed by the crushing teeth. These crushing teeth are manufactured using a special alloy formulation that incorporates multiple rare elements; after casting and machining, they undergo quenching treatment, resulting in high strength combined with adequate toughness, excellent wear resistance, and a long service life.

(3) Safety Pin Device

The reducer plays a critical role in the crusher and must be protected. A shear pin device has been installed between the reducer and the toothed rollers: under heavy-load starting conditions or when the load exceeds the design capacity, the shear pin will shear, causing the motor and reducer to continue rotating while the toothed rollers remain stationary. The sensor then sends a signal to the PLC, which immediately shuts down the motor, thereby providing reliable protection for both the reducer and the motor. The shear pin is low-cost and easy to replace, significantly reducing equipment maintenance expenses. In principle and performance, the shear pin functions similarly to a fuse in an electrical circuit. This crusher employs shear crushing technology, virtually eliminating over-crushing. Its compact size and light weight make it well suited for primary, secondary, and tertiary crushing applications in underground, indoor, and open-air crushing systems.

This crusher is equipped with high-end components sourced both domestically and internationally.

1. Reducer: Imported reducers from German brands SEW and Flender are used.

2. Coupler: Imported, Voith brand from Germany

3. Bearings: SKF (Sweden), Timken (USA)

4. Couplings: American Lemo-Falk serpentine couplings and gear-type couplings from the Zhengzhou Institute of Mechanical Research. 5. Motors: ABB from Shanghai, Jiamusi Motor, and Nanyang Explosion-Proof Motors.

The series of screening-type double-tooth roll crushers is the result of our company’s extensive research and development, conducted over many years by integrating cutting-edge technologies from both domestic and international sources, while taking into account China’s specific conditions and collaborating closely with leading universities and major coal mines.

The main features are as follows:

1. The crushing teeth, manufactured using special materials and processes, exhibit high strength, high hardness, excellent wear resistance, and long service life.

2. A torque-limiting hydraulic coupling is used, along with a torque-limiting drum-type gear coupling, providing dual overload protection.

3. The production capacity of this product series ranges from 50 t/h to 5,000 MWh.

4. Compatible with any of the following supply voltages: 380 V, 660 V, or 1140 V.

5. The maximum feed particle size can exceed 1,500 mm.

6. Dual functions of screening and crushing.

7. High power, high efficiency, and a clear price advantage compared with foreign products.

8. Adopt a self-propelled structure for convenient maintenance.

9. Automatic refueling to ensure the canal’s reliability.

User Unit: Sanjiaoh River Mine, Huozhou Bureau, Shanxi Province (3 million tons/year)

User Unit: Longgu Mine of Shandong Xinwen Group (9 million tons/year)