KNOWLEDGE BASE
CONVEYOR BELT GLOSSARY
A working reference for engineers, buyers, and technicians who design, specify, or maintain belt conveyors. 50 entries — each with a one-line definition, an in-depth explanation, the formulas that matter, and references to DIN 22101, ISO 5048 / 14890 / 15236, and the CEMA orange book where applicable. Cross-links lead directly to the relevant product pages and free engineering calculators.
Browse by category
Belt Types & Construction
10Conveyor Belt · Fabric Conveyor Belt · Steel Cord Conveyor Belt
Drives & Pulleys
8Drive Pulley · Pulley Lagging · Motorized Drive Roller
Idlers & Supports
7CEMA Idler Class · Impact Idler · Self-Aligning Idler
Geometry & Design
7Trough Angle · Surcharge Angle · Belt Sag
Forces & Physics
8Effective Tension (Te) · Friction Factor (f) · Capstan Equation (Eytelwein)
Bulk Materials
4Angle of Repose · Lump Size · Bulk Density
Industry Standards
3DIN 22101 · CEMA Standard · ISO 14890
Maintenance & Operations
3Belt Mistracking · Overland Conveyor · Transfer Chute / Transfer Point
All terms
Showing 50 of 50 terms
Belt Types & Construction (10)
- Chevron Conveyor BeltA chevron conveyor belt has raised V- or U-shaped rubber profiles vulcanized onto the top cover, allowing it to convey loose bulk material at incline angles of up to 30–40°.
- Conveyor BeltA conveyor belt is a continuous loop of reinforced rubber or polymer that carries bulk material or unit loads between two or more pulleys driven by an electric motor.
- Cover CompoundCover compound is the rubber formulation laminated to the top and bottom of a conveyor belt carcass, classified by abrasion (D, H, L), heat, oil or anti-static resistance per DIN 22102 / ISO 10247.
- Fabric Conveyor Belt(EP / NN)A fabric conveyor belt uses 2–6 textile plies (typically polyester warp / nylon weft, designated EP) bonded with rubber skim coats to form a flexible, high-strength carcass.
- Heat-Resistant Conveyor BeltA heat-resistant conveyor belt uses EPDM- or SBR-based cover compounds graded T1–T4 (continuous service from 100 °C to 175 °C) to carry hot sinter, clinker, coke and cement without cover blistering.
- Pipe Conveyor BeltA pipe conveyor belt is a flat belt rolled into a closed tubular shape by a hexagonal array of idlers, fully enclosing the cargo and allowing horizontal curves and incline angles up to 30°.
- Sidewall Conveyor BeltA sidewall conveyor belt has vertical corrugated rubber walls vulcanized to both edges and transverse cleats across the carrying surface, allowing material to be conveyed at angles up to 90°.
- Solid Woven Belt (PVC/PVG)(PVC/PVG)A solid woven belt has a single-piece woven synthetic carcass fully impregnated with PVC or PVG, giving flame retardant, anti-static behaviour mandatory in many underground coal mines.
- Steel Cord Conveyor Belt(ST)A steel cord conveyor belt embeds parallel galvanized steel cables longitudinally in a rubber carcass, designated ST500–ST5400 for breaking strengths from 500 to 5400 N/mm.
- Vulcanized Belt SpliceA vulcanized belt splice is a heat-cured rubber joint that reconnects the two ends of a conveyor belt, restoring 70–90 % of the carcass breaking strength versus 35–50 % for mechanical fasteners.
Drives & Pulleys (8)
- Bend PulleyA bend pulley is a non-powered conveyor drum that simply redirects the belt path — around a gravity take-up, behind a drive arrangement, or past structural obstructions — without transmitting torque.
- Drive PulleyThe drive pulley is the powered drum of a conveyor that transmits torque from the gearbox to the belt by friction, generating the effective belt tension Te that overcomes all resistances.
- Holdback BrakeA holdback brake is a one-way clutch fitted to the drive shaft of an inclined conveyor that locks against reverse rotation, preventing a loaded belt from running back when the drive stops.
- Motorized Drive Roller(MDR)A motorized drive roller (MDR) is a conveyor pulley with the gear-motor integrated inside the drum shell, eliminating external gearboxes, couplings and exposed drives.
- Pulley LaggingPulley lagging is a rubber, ceramic or polyurethane layer bonded to the drum surface of a conveyor pulley to increase the belt-to-drum friction coefficient and protect the drum from wear.
- Snub PulleyA snub pulley is a small-diameter pulley placed just before or after a drive pulley to deflect the belt and increase its wrap angle from 180° to 210–230°, boosting maximum transmissible Te.
- Tail PulleyThe tail pulley is the non-driven drum at the loading end of a conveyor that receives the return belt and reverses it 180° back onto the carrying side.
- Take-up PulleyA take-up pulley sits on the return strand and is moved by a gravity weight or a screw mechanism to apply the slack-side tension T2, absorbing belt elongation and preventing sag and slip.
Idlers & Supports (7)
- CEMA Idler ClassCEMA idler class (A, B, C, D, E, F) is the U.S. standard rating system that groups conveyor idler rolls by shell thickness, bearing size and maximum load — A is lightest duty, F is heaviest.
- Garland IdlerA garland idler is a chain-suspended idler assembly of three or five rollers strung together that flexes under impact, absorbing peak loads at the loading point of heavy-duty mining conveyors.
- Impact IdlerAn impact idler is a troughing idler whose steel shell is wrapped in thick rubber rings to absorb the impact of falling material at the loading point and protect the belt from cuts and gouges.
- Return IdlerA return idler is a single roller (or V-shaped two-roller set) below the carrying strand that supports the empty return belt at typical spacing of 3 m, with self-cleaning variants used in dirty applications.
- Self-Aligning IdlerA self-aligning idler is a pivoting troughing or return idler that automatically steers a mistracking conveyor belt back to centre by tilting its outer rolls into the belt's drift direction.
- Transition IdlerA transition idler is an adjustable idler frame placed near the head and tail pulleys whose wing rolls gradually flatten from the design trough angle down to horizontal, easing the belt onto the flat pulley face.
- Troughing Idler SetA troughing idler set is a frame of three carrying rollers — one horizontal centre and two inclined wings at 20/30/35/45° — that shapes the belt into a trough cross-section to maximize material-carrying capacity.
Geometry & Design (7)
- Belt SagBelt sag is the vertical drop of a conveyor belt between two adjacent idlers under the combined weight of belt and load, typically kept below 1.5 % of idler spacing on the carry side.
- Edge DistanceEdge distance is the lateral clearance between the belt edge and the skirtboard, sidewall or structural steel of a conveyor — typically 50–100 mm — sized to prevent spillage and edge wear.
- Idler SpacingIdler spacing is the longitudinal distance between consecutive idler frames on a conveyor — typically 1.0–1.5 m on the carrying side and about 3 m on the return — sized against belt sag and impact at load points.
- Surcharge AngleSurcharge angle is the angle of the material heap above the rim of a troughed conveyor belt during conveying, typically 5–25° lower than the static angle of repose due to belt vibration.
- Take-up TravelTake-up travel is the minimum stroke a take-up assembly must provide to absorb belt elongation — about 1.5 % of conveyor length for steel cord and 1.5–3 % for fabric belts, plus splice and reserve allowances.
- Transition LengthTransition length is the distance from the last full troughing idler to the terminal pulley — typically 1.0× to 2.5× belt width — over which the belt flattens; insufficient length causes edge over-tension and splice failure.
- Trough AngleTrough angle is the angle between the outer (wing) idlers and the horizontal centre idler in a three-roll troughing set, typically 20°, 30°, 35° or 45°, which controls belt cross-section and capacity.
Forces & Physics (8)
- Breaking Strength (kN/m)Breaking strength is the minimum tensile force per metre of belt width at which a new belt's carcass fails — e.g. an EP500 belt is rated 500 N/mm = 500 kN/m — used with the safety factor to derive working tension.
- Capstan Equation (Eytelwein)The Capstan or Eytelwein equation T1/T2 = e^(μθ) describes the maximum tension ratio a belt can sustain across a driven pulley before slipping, given the friction coefficient μ and the wrap angle θ in radians.
- Effective Tension (Te)(Te)Effective tension (Te) is the net tangential force that the drive pulley must transmit to the belt to overcome all motion resistances; it is the fundamental input for motor power and belt selection.
- Friction Factor (f)(f)The friction factor f is the dimensionless DIN 22101 coefficient (typical range 0.018–0.030) that lumps all idler bearing, belt indentation and seal friction into a single number for main-resistance calculation.
- Ply Rating (EP200, NN200, etc.)Ply rating designates a fabric belt carcass by its fabric type (EP = polyester-nylon, NN = nylon-nylon) and per-ply tensile strength in N/mm — e.g. EP200/4 means 4 plies × 200 N/mm = 800 N/mm.
- Safety Factor (SF)(SF)Safety factor is the ratio of belt breaking strength to maximum working tension; DIN 22101 sets S₀ ≈ 8 for fabric belts and 6.7 for steel cord, with reductions allowed when splice quality is verified.
- T1 (Tight Side Tension)(T1)T1 is the maximum belt tension at the drive pulley entry — the sum of slack-side tension T2 plus effective tension Te — and is the value used to size belt rating in kN per metre of belt width.
- T2 (Slack Side Tension)(T2)T2 is the minimum belt tension on the slack side of the drive pulley; it must exceed Te / (e^(μθ) − 1) per Eytelwein to prevent drive slip, and it is set in the field by the take-up.
Bulk Materials (4)
- Abrasiveness RatingAbrasiveness rating is a qualitative classification (Low, Medium, High, Very High) of how aggressively a bulk material wears belt covers and idler shells, used to specify cover grade and idler material.
- Angle of ReposeThe angle of repose is the steepest angle, measured from horizontal, at which a static pile of loose bulk material is stable without sliding; for most granular ores and aggregates it lies between 30° and 45°.
- Bulk DensityBulk density is the mass per unit volume of a bulk material including the voids between particles — ranging from 240 kg/m³ (wood chips) to 2880 kg/m³ (barite) — used directly in capacity and power calculations.
- Lump SizeLump size is the maximum particle dimension of a bulk material — designated as 'sized' (uniform) or 'run-of-mine' (mixed) — and it drives idler spacing at load points, belt width sizing and impact rating.
Industry Standards (3)
- CEMA Standard(CEMA)CEMA is the U.S. Conveyor Equipment Manufacturers Association, publisher of 'Belt Conveyors for Bulk Materials' (the orange book) and related standards covering idler classes, pulley diameters and belt design.
- DIN 22101DIN 22101 is the German standard 'Continuous conveyors — Belt conveyors for bulk materials — Basis for calculation and design', the de facto international reference for belt conveyor engineering.
- ISO 14890ISO 14890 is the international standard 'Conveyor belts — Specification for rubber- or plastics-covered conveyor belts of textile construction for general use', defining test methods, cover grades and dimensions for fabric belts.
Maintenance & Operations (3)
- Belt MistrackingBelt mistracking is the lateral drift of a conveyor belt away from its centred path, causing edge wear, spillage and splice damage — corrected with self-aligning idlers, pulley crowning and training idlers.
- Overland ConveyorAn overland conveyor is a long-distance cross-country belt conveyor — typically 1 km to 25 km or more in a single flight — used to replace truck haulage in mining, almost always built with steel cord belt.
- Transfer Chute / Transfer PointA transfer chute (or transfer point) is the junction where one conveyor discharges onto another; chute geometry, impact bars and dust suppression are engineered to minimize belt impact, spillage and dust emission.