Sources of Power and Machinery in Farm Operations

Comprehensive vocabulary flashcards generated from Module 2 (Sources of Farm Power, Motors, Internal Combustion Engines, and Power Transmission Systems).

Cropping Intensity

The number of times a crop is planted and harvested per year in a given agricultural area.

Human Power (Farm Output)

The average continuous power developed by an agricultural worker under normal conditions, equivalent to approximately $75\,watts$ or $0.1\,hp$.

Labour Peaks

Periods in a crop production system characterized by exceptionally high demands for human labor during unmechanized field operations such as transplanting, weeding, and harvesting.

Animal Power (Farm Output)

The average power output generated by draft animals (such as carabaos, oxen, or horses) for agricultural work, equal to approximately $750\,watts$ or $1\,hp$.

Carabao Optimum Draft

The continuous draft load a carabao can sustain without excessive fatigue, approximately equal to $15\%$ of its total body weight.

Effective Field Capacity ($C$)

The actual rate of land processing accomplished by a farm implement or machine per unit of time, calculated as $C = \frac{S \times W \times Eff.}{10}$ in units of $ha/hr$.

Biomass

A non-fossilized, biodegradable organic material sourced from agricultural residues, bagasse, rice hulls, coconut husks, wood chips, or landfill waste to produce bioenergy.

Geothermal Energy

Renewable energy derived from thermal energy stored in deep underground reservoirs of hot fluids within the Earth's crust.

Micro-hydro

A classification of hydropower generation capacity ranging from $1\,kW$ to $100\,kW$.

Mini-hydro

A classification of hydropower generation capacity ranging from $101\,kW$ to $10\,MW$.

Large Hydro

A classification of hydropower generation capacity exceeding $10\,MW$.

Power

The rate of doing work over time, commonly expressed in horsepower ($hp$) or kilowatts ($kW$), where $1\,hp = 0.75\,kW$.

Electric Motor

An electro-mechanical device designed to convert electrical energy into mechanical rotary power.

Ampacity

The electric current, measured in amperes, that a conductor can carry continuously under operating conditions without exceeding its temperature rating.

Locked-Rotor Current

The maximum current drawn by an electric motor when starting from a complete standstill.

Service Factor

A multiplier indicating the maximum permissible overload an electric motor can continuously carry under safe operating temperatures.

Breakdown Torque

The maximum peak torque an electric motor can produce during an overload condition without stalling.

Starting Torque

The locked-rotor torque generated by an electric motor at zero rotational speed to initiate movement of a load.

Split-Phase Motor

A single-phase AC induction motor that develops starting torque using an auxiliary winding displaced $90^{\circ}$ in space from the main winding.

Capacitor-Start Induction-Run Motor

A single-phase AC motor that employs a series capacitor in its auxiliary starting circuit, which is disconnected by a centrifugal switch as the motor nears full speed.

Squirrel-Cage Motor

An AC motor featuring a secondary rotor winding composed of identical copper or cast-aluminum bars joined at both ends by conducting rings.

Fractional-Horsepower Motor

An electric motor built in smaller frame sizes with a continuous power rating of less than $1\,hp$ at $1700\,rpm$ to $1800\,rpm$.

Integral-Horsepower Motor

An electric motor with a continuous power rating of $1\,hp$ or greater at $1700\,rpm$ to $1800\,rpm$.

Internal Combustion Engine

A heat engine in which fuel combustion occurs within the working fluid inside the engine cylinder, expanding gas to produce mechanical power.

Four-Stroke-Cycle Engine

An internal combustion engine that requires four linear piston movements (intake, compression, power, exhaust) or two crankshaft revolutions to complete one cycle.

Two-Stroke-Cycle Engine

An internal combustion engine that completes its power cycle in two piston strokes or one full revolution of the crankshaft.

Spark-Ignition Engine

An internal combustion engine (typically fueled by gasoline) that uses an electric spark plug to ignite a compressed air-fuel mixture.

Compression-Ignition Engine

An internal combustion engine (typically fueled by diesel) that relies on the high heat of compressed air to self-ignite injected fuel.

Top Dead Center (TDC)

The uppermost position reached by an engine piston as it moves toward the top of the cylinder.

Bottom Dead Center (BDC)

The lowermost position reached by an engine piston as it moves toward the bottom of the cylinder.

Piston Displacement

The volume swept by the piston during its stroke from Bottom Dead Center (BDC) to Top Dead Center (TDC).

Clearance Volume

The enclosed volume remaining inside an engine cylinder above the piston head when the piston is at Top Dead Center (TDC).

Compression Ratio

The ratio of total cylinder volume at BDC ($TV$) to the clearance volume at TDC ($CV$), calculated as $CR = \frac{TV}{CV}$.

Tractor Transmission System

A speed-reducing power train consisting of gears, shafts, and clutches that transfers power from the engine flywheel to the drive wheels or power take-off (PTO).

V-Belt

A flexible power transmission loop made of cord and rubber with a trapezoidal cross-section, fitted into grooved pulleys to drive short-center shafts.

Chain Pitch

The linear distance between the centers of adjacent joint link pins in a roller chain.

Spur Gear

A cylindrical gear with straight teeth cut parallel to its axis of rotation, used to transfer power between parallel shafts.

Module (Gear Metric)

A standard metric measurement defining gear tooth size, calculated as the pitch diameter divided by the total number of teeth ($mm/tooth$).

Spur Gear Nomenclature

The physical features defining gear tooth geometry, including the pitch circle, addendum circle, dedendum circle, working depth, face width, and tooth thickness.