Scraper Conveyor

The scraper conveyor is a mechanical equipment for conveying materials, mainly used for short-distance horizontal conveying or inclined conveying with an angle not exceeding 15 degrees. It consists of a frame, rollers, scrapers, chains, a motor, a reducer and other components.

1.Solid structure, able to withstand external forces such as impact, collision, crushing and extrusion from coal, gangue or other materials.

2.Adapt to the needs of uneven floor and curved pushing of coal mining face, and can bear bending in vertical and horizontal directions.

3.Low machine body, easy to install.

4.Can also serve as the running track for shearers.

5.Reversible operation for convenient handling of bottom chain faults.

6.Can be used as the fulcrum for the front section of hydraulic supports.

1.Convey coal cut by the shearer or spalling coal from the coal face.

2.Serve as the running track for the shearer.

3.Act as a fixed fulcrum for pulling and moving hydraulic supports.

4.Clear loose coal on the working face.

5.Suspend cables, water pipes, emulsion pipes and other pipelines.

The scraper conveyor is composed of a headstock, a tailstock, middle sections, a scraper chain, a power unit, a transition trough, a deflection trough, a pushing pad frame and other components.

Determination of Working Face Direction of Scraper Conveyor:

Left working face: Facing the coal wall, the headstock is on the left side; or standing at the headstock and facing the tailstock, the working face with the coal wall on the left side is defined as a left working face.

Right working face: Facing the coal wall, the headstock is on the right side; or standing at the headstock and facing the tailstock, the working face with the coal wall on the right side is defined as a right working face.

(1) Headstock

The headstock is the unloading end of the entire conveyor, with both sides connectable to the power unit and the bottom connected to the pad frame. Classified by unloading method, headstocks are divided into end unloading type and cross side unloading type.

The headstock is mainly composed of a headstock frame, a sprocket shaft assembly, press blocks, guard plates, a chain unloader and other components.

The chain unloader functions to force the round link chain to disengage from the sprocket at the normal separation point, and timely remove foreign matters trapped in the sprocket grooves. This prevents the chain from jamming on the sprocket teeth and causing chain breakage or tooth chipping accidents, thus ensuring the normal meshing of the sprocket and the scraper chain. When the two stressed and worn parts (upper and lower) are abraded, they can be repaired by surfacing welding for reuse.

The sprocket shaft assembly is the driving component for the operation of the scraper chain, mainly consisting of a shaft, bearings, bearing housings, sealing parts, sprockets, locating sleeves and other components. It adopts centralized thin oil lubrication with an attached oil tank for oil storage, using N320 extreme pressure gear oil as the lubricant. The lubricating oil enters the sprocket shaft assembly through the hose of the oil tank, which facilitates oil filling and prolongs the service life of the assembly.

(2) Power Unit

The power unit is composed of a motor, a reducer, a connecting device, a coupling, a chain tightener and other components. The power transmission path is as follows: the torque of the motor is transmitted to the reducer input shaft through the coupling; after speed reduction by the reducer, the internal spline (external spline) of the output shaft meshes with the external spline (internal spline) of the headstock sprocket shaft, and the sprocket drives the scraper chain to move linearly. There are generally four types of power connection methods between the motor and the reducer: hydraulic coupling, half coupling, torque-limiting friction clutch and variable speed coupling.

(3) Middle Section

The middle section is a key and mass-produced component of the scraper conveyor. It is used to convey coal, bear the weight of the shearer and the pushing force of hydraulic supports, and is mainly composed of middle troughs, cable troughs, dumbbell pin assemblies, pin row assemblies and other components.

Cast-welded middle troughs consist of cast baffle trough sides, cast scraper trough sides, middle plates, bottom closing plates, square hole plates, pin row seats and other components. Adjacent middle troughs are connected by dumbbell pins.

A skylight middle trough is equipped every ten sections for easy inspection of the bottom chain. Pin rows are mounted on the middle troughs to serve as the traction track for the shearer.

Cable troughs are fixed on the middle troughs by bolts. They prevent coal from spilling to the goaf side and act as a support for the shearer's cables and water pipes, as well as the emulsion hoses of hydraulic supports. A special cable trough is installed in the center of the conveyor to facilitate the cable connection of the shearer.

(4) Tailstock

It is the rotating end of the scraper chain and forms a closed-loop movement of the scraper chain together with the headstock. It is divided into ordinary tailstock and telescopic tailstock. The telescopic tailstock is composed of a tailstock frame, a fixed trough, a sprocket shaft assembly, press blocks, guard plates, a chain unloader, a telescopic oil cylinder and other components.

The power unit is mounted on the tailstock frame in a side-hung manner. The small end of the tailstock is connected to the transition trough or deflection trough via dumbbell pins. The telescopic tailstock is used to adjust the tightness of the scraper chain and is available in both automatic and manual forms.

(5) Scraper Chain

It takes middle troughs and other components as the track and the motor and other power units as the driving force to convey coal cut by the shearer. It consists of scrapers, chains, press plates, bolts, nuts and other parts. Most scrapers are forged; a small number of large-specification scrapers are forged in the middle and cast at both ends. Press plates are fully forged. For small-specification conveyors, press plates and bolts are integrated into a single component, which we call E or U-shaped bolts.

Scrapers, press plates, bolts and nuts are wear parts, so spare parts shall be ordered for standby use.

(6) Pushing Pad Frame

It acts as a bridge connecting the headstock (or tailstock, transition trough) of the scraper conveyor with the front frame of the hydraulic support. As the power unit needs to be installed on the headstock and tailstock, the pushing point has to be set back, which is realized by the pushing pad frame (beam).