Dictionary

Car tires (Chapter 6) i s one of the most important elements, which is an elastic shell located on the rim of the wheel. The tire is designed for absorbing minor oscillations that are caused by imperfections of the road surface, the implementation and perception of forces arising in the contact patch, and to ensure high traction properties. According to the type of construction, depending on the location of the cord (frame element), there are diagonal and radial tires. 

In radial tires, the cord threads are located at the shortest distance between the tire sides. In diagonal tires they are located at some angle and intersect each other. Currently, only radial tires are installed on passenger cars. Diagonal tires are still used on motorcycles, mopeds, earthmoving and agricultural machinery.

Aquaplaning is a condition in which a film of water separates a tire and a road surface. It occurs when the pressure of the wedge of water, not pushed out of the area of contact of the tire with the road, raises the tire above the road. The tendency to aquaplaning depends on the thickness of the water film on the road surface, the speed of the car, the shape of the tread pattern, its wear and the pressure exerted by the tire on the road.

Dampening is the process of damping shock loads and oscillations.

Ampere (A) is a unit for measuring current strength.

Ampere-hour (A·h) is a unit of measurement of battery pack capacity.

Anti-freezing agent (Chapter 4) is an aqueous solution of alcohols, glycols, glycerin and some inorganic salts, which does not freeze at low temperatures and allows reducing the freezing point of the coolant and increasing its anticorrosion properties.

Drum brake (Chapter 7) is type of brake mechanism, the main parts of which are the brake drum and brake pads with brake linings. Drum brakes are made in the form of an internal shoe brake, the pads of which are pressed to the inner surface of the brake drums rotating with the wheels by means of pistons in the wheel cylinder. This way the car is slowed down.

Hopping is the amount of radial or axial deviation when rotating the body, such as the brake disc.

Lateral clearance is the magnitude of the stroke (maximum distance) between two elements of the mechanism, one of which is necessarily stationary.

Shaft — is the element of the mechanism in the form of a rod, which is designed for transmitting torque.

Watt (W) is a unit of power.

Top Dead Center (TDC) (Chapter 4) is the position of the piston inside the cylinder, which corresponds to the maximum distance between any point of the piston and the axis of rotation of the crankshaft (conditionally the initial position of the crankshaft, zero degrees of rotation of the crank).

Wobbling - see "Shimmy"

Water pump (Chapter 4) is a device with mechanical drive, which is designed for forced circulation of coolant inside the engine cooling system.

Volt (V) - a unit of measurement for electrical voltage

Fuel injection (Chapter 4) is electronically dosed fuel supply to the engine intake manifold (central or single point injection) or directly to the cylinder (distributed injection).

All-season oil (Multigrade Oil) (Chapter 4) is engine oil, which meets the requirements of more than one viscosity level according to the SAE (Society of Automotive Engineers) classification (see "SAE Viscosity Levels"). Therefore, it may be suitable for use in a wider temperature range than oil with a single viscosity level.

Sleeve is a cylindrical part, which is made out of metal or other material and is used between two moving parts.

Electric current rectifier is a mechanical, electro vacuum, semiconductor or other device, which is designed for converting alternating input electric current into direct output electric current.

Valve opening height (Chapter 4) is the maximum distance that the valve rises above the seat during opening.

Viscosity - the property of fluid bodies (liquids and gases) to resist the movement of one part of them relative to another

Generator (Chapter 10) is a device, which is designed for converting the mechanical energy of rotation of the internal combustion engine into electrical energy for recharging the battery and powering the electrical circuit of the car.

Sealer is a polymeric substance from liquid to pasty form, which possesses the ability to seal various connections, seams, and joints.

Hygroscopic property (Chapter 7) is the property of some substances to absorb water vapor from the air. For example, brake fluids have this property. Thus, in order to maintain the qualities necessary for the normal functioning of the brake system, it is necessary  to observe the tightness of the storage tanks, as well as the elements of the brake system.

Cylinder sleeve (Chapter 4) is a cylindrical part, which is made out of alloy high-carbon steel, inserted into the cylinder block.

Hypoid (hyperboloid) transmission (Chapter 5) is a special type of helical gearing performed by bevel wheels with intersecting axles. Hypoid gear wheels can have oblique, or curved, teeth. The angle of intersection of the axes is usually equal to 90°.

Main gear (Chapter 5) is the gear mechanism of transmission of cars, which is used for transferring and change of the direction of a twisting moment from a cardan shaft (transmission) to driving wheels, and also for change of traction.

Double helical gears (chevron gears) are gears that are the connection of two helical gears with the opposite arrangement of teeth (in the form of the letter V). The axial moments of both halves of such a wheel are mutually compensated. Thus, there is no need to install axles and shafts in special bearings.

Knocking (Chapter 4) is a supersonic complex, which consists of a shock wave and an exothermic chemical reaction behind it. Spark-ignition internal combustion engines are rapidly destroyed by detonation, as they are designed for slow combustion of the fuel-air mixture. Rapid knocking combustion dramatically increases the pressure inside the combustion chamber, which leads to rapid engine failure. In case of strong detonation this can happen in less than a minute. Fuel with a higher octane number resists knocking better.

Diaphragm (Chapter 7) is an elastic membrane, which acts as a barrier between two chambers with variable pressure.

Diaphragm spring (Chapter 5) is an elastic element in the form of a diaphragm, which provides a uniform downforce around the circumference.

A diode is a semiconductor device containing one pn-junction, which ensures the movement of electric current in only one direction.

Disc brake (Chapter 7) is a brake mechanism in which, unlike the drum brake, the brake pads are pressed against the brake disc.

Free length - the length of the element measured in the unloaded state.

Liquid crystal display (LCD) is a flat display, which is based on liquid crystals, as well as a monitor based on such a display.

Bully - the formation as a result of setting a furrow that is visible to the naked eye with the pushing of the material both to the sides and in the direction of sliding.

Clearance - the distance between two parts (for example, between the piston and cylinder, between the bearing and the shaft).

Corner tightening is a method of tightening a threaded connection by turning a bolt or nut to a certain angle. A special corner collar is used to tighten the corner.

Toothed drive belt (Chapter 4) is a belt, which is designed for transmitting torque between the shafts without slipping (for example, to drive the gas distribution mechanism).

Needle roller bearing is a type of rolling bearing, in which the rolling element is a small diameter rollers (needles) placed between two rings (inner and outer) of high carbon steel.

Tire wear indicator is an indicator in the form of transverse stripes, which becomes visible in case of maximum wear of the tire tread. It indicates the need to replace the tire with a new one.

Clock-type indicator is a measuring device with an arrow indicator, which is designed for measuring the backlash of the moving elements of the mechanisms.

Surface ignition is a premature self-ignition of the fuel-air mixture from a hot substance, such as soot, which is formed inside the combustion chamber, or from overheated (more than 700- 800 ° C) parts: spark plugs, heads, exhaust valves, etc. Surface ignition disrupts the process of normal combustion of gasoline, because it is directly related to the development or occurrence of knocking. Fuel combustion in case of surface ignition is similar in its physical nature to normal combustion, but it starts earlier, on a larger area and goes faster. Premature ignition is a self-developing process. Thus, the moment of self-ignition occurs earlier and earlier. The pressure and temperature rise inside the combustion chamber, the maximums of which can be reached before the arrival of the piston in TDC. All this causes an increase in the load on the parts of the cylinder-piston group and the crankshaft. It causes increase of the noise of the engine, including the knocking of the muffled tone, which is quite difficult to distinguish from a number of engine sounds. But most importantly - surface ignition leads to a significant increase in thermal loads on the surface forming the combustion chamber. As a rule, the piston melts and/or burns out and the spark plug electrodes melt.

Camber (Chapter 6) — see “Camber” section.

Combustion chamber (Chapter 4) is the volume, which is created by the set of engine parts in which the combustion of the fuel-air mixture takes place. The design of the combustion chamber is determined by the operating conditions and arrangement of the valve group.

Cardan shaft (Chapter 5) is a device for transmitting torque between units, relative position of which in space is not constant: for example, from the gearbox (transfer case) to the drive axles in case of a classic or all-wheel drive layout. It is also used in an injury-safe steering column for connecting the steering shaft and steering drive (steering gear or steering rack).

Caster angle (Chapter 6) is the angle between the vertical and the projection of the axis of rotation of the wheel on the longitudinal plane of the car. The longitudinal inclination provides self-alignment of steering wheels due to speed of the car.

Catalytic converter (Chapter 4) is an element, which purifies the exhaust gases of internal combustion engines by converting toxic components into more harmless compounds.

Oxygen sensor is the sensor for measuring oxygen content in the exhaust manifold of the engine. It allows estimating the amount of free oxygen remaining in the exhaust gases.

Valve (Chapter 4) is a device, which is installed on a pipeline or vessel and designed for opening or closing under certain conditions (increase of pressure inside the tank, change the direction of flow of the medium inside the pipeline). Valves have a large number of designs. Valves can be single-seat and double seat, the latter are usually used only as distribution and regulating ones. Depending on the direction of flow through the valve, the valves are divided into pass-through, process and angular. In press-through valves, the working medium at the outlet of the housing has the same direction as at the inlet. Process valves are checkpoints with a straight flow line. They have lower hydraulic resistance if compared to through-holes. In angle valves, the direction of flow of the medium at the outlet is perpendicular to the direction of flow at the inlet.

Valve clearance (Chapter 4) is the clearance between the valve rod and the push rod (camshaft), which is designed to compensate for thermal expansion during operation of the internal combustion engine.

Wheelbase (Chapter 3) is the distance between the axles of the front and rear wheels of the car.

Compression (Chapter 4) is a force on the gaseous body, leading to a decrease in its volume, as well as to an increase in pressure and temperature. Compression is carried out in compressors, and also during the operation of the internal combustion engine and other devices.

Conical gears (Chapter 5) are gears that are used for changing the direction of torque by an angle of 90 °.

Locknut (lock nut) is a nut, which is used for fixing an adjusting nut or other threaded elements in one position.

Crankshaft (support) neck is a mounting surface of crankshaft or camshaft.

Crankshaft bearing liners are bimetallic plain bearings that are mounted on crankshaft or camshaft bearings.

Gearbox (transmission) (speed-change gearbox, gear-shift mechanism) - obsolete terms, currently not used in technical terminology) (Chapter 5) is a mechanism, which is used in the transmission of vehicles with internal combustion engines. It is designed for changing the engine torque in magnitude and direction, as well as long-term disconnection of the powertrain from the engine (wheels or tracks). There are mechanical and automatic transmissions according to the type of control.

Short circuit is an electrical connection of two points of an electric circuit with different values of potential, not provided by the design of the device and disrupting its normal operation. A short circuit can occur when the insulation of live elements is disrupted or due to mechanical contact of elements operating without insulation. A short circuit is also a condition, when the load resistance is less than the internal resistance of the power supply.

Spiral wheel (Chapter 5) is a gear, the teeth of which are located at an angle to the axis of rotation. It provides smoother, and therefore less noisy gearing of gear teeth. The disadvantage of spiral wheels is the occurrence in the process of mechanical moment, which is directed along the axis of rotation of the gear.

This requires the use of thrust bearings, as well as increased heat generation, as a consequence of increased friction surfaces of the teeth. Double spiral wheels (see "Double Helical Gears") are devoid of these problems.

Torque (moment of force) is a physical value, which characterizes the rotational action of force on a solid body.

Car body (Chapter 9) is the part of the car, which is designed for accommodating passengers and cargo. The car body is attached to the car frame. There are also  frameless car bodies that at the same time perform a function of a frame - all other devices and units of the car are fastened to them.

Lambda probe (λ-probe) - see "Oxygen Sensor".

Pressure gauge is a device designed to measure pressure.

"Mass" - the closure of the electrical circuit in the car to the battery through the body.

Micrometer is a particularly accurate measuring device, which is designed for measuring outer diameters.

Multimeter is a measuring device, which is designed for measuring voltage, current and resistance of an electrical circuit.

Bottom Dead Center (BDC) (Chapter 4) is the position of the piston inside the cylinder, which corresponds to the minimum distance between any point of the piston and the axis of rotation of the crankshaft (conditionally the initial position of the crankshaft, zero degrees of rotation of the crank).

Nutrometer - a measuring device designed to measure the inside diameter of a hole.

Newton is a unit of measure for force.

Newtonometer (N ∙ m) is a unit of torque measurement.

Overrunning clutch (freewheel clutch) (Chapter 5, Chapter 10) is a part of a mechanical transmission, which prevents the transmission of torque from the driven shaft back to the drive shaft if for some reason the driven shaft starts rotating faster. The most well-known application of the overrunning clutch is in the bicycle drive. At the moment when the rider stops turning the pedals and the bike continues moving by inertia, the overrunning clutch is activated. It disconnects the wheel from the pedals, and they do not hit the feet. Sometimes overrunning clutches are used in cars with two-stroke engines, for which the "engine braking" mode is impossible due to the design features (more precisely, the  method of lubrication), which can disable them. Another widespread use of the overrunning clutch is its use in engine starters for preventing the destruction of the starter by a running engine.

Ovality is the difference in hole diameters measured in mutually perpendicular directions.

Octane number (Chapter 4) is a value, which characterizes the resistance of the fuel to cranking.

Ignition advance (Chapter 4, Chapter 10) is ignition of the working mixture in the engine cylinder until the piston reaches TDC.

Axial clearance (axial backlash) is a backlash of an element in the axial direction.

Axle is an element of the mechanism in the form of a core which, unlike a shaft, does not transfer the twisting moment, and is intended exclusively for positioning of rotating details.

Coolant (Chapter 4) is the working fluid of the engine cooling system. it consists of water, antifreezing solution, special additives that protect the cooling system of the internal combustion engine from corrosion processes and the fluid itself from thermochemical destruction. Ethylene glycol-based coolants are currently widely used. All ethylene glycol coolants differ in quality only in a set (or absence) of necessary additives and degree of dilution with water. Glycol-based coolants are not dangerous to humans. They are poisonous only when ingested.

Gear ratio (Chapter 5) is the ratio of the number of teeth leading to the number of teeth of the driven gear in the gear, the number of teeth of the worm wheel to the number of worms in the worm gear, the number of teeth of a large sprocket to the number of teeth of small chain drive, and large diameter pulley (or roller) to a smaller diameter in the belt or friction transmission.

Alternating current is an electric current, which varies periodically in magnitude and direction (usually sinusoidal).  This type of current has properties that are favorable for the transmission of electricity over distances, because it allows you to easily transform the voltage in transformers. Three phase AC generators are more widely used in cars due to their more compact dimensions compared to DC generators.

Flat dipstick is a strip of a certain thickness out of high-alloy steel, which is designed for measuring the gaps between parts.

Electrolyte density is a value that characterizes the state of the battery electrolyte.

Suspension (Chapter 6) is a set of parts, assemblies and mechanisms that connect the body of the machine with the supporting elements (wheels, rollers, skis, etc.). The suspension is intended for reducing dynamic loads and ensuring their uniform distribution on basic elements while moving. It also serves for increase of traction qualities of the car.

Bearing is a mechanical element, which is used for reducing friction and related processes of wear and heat generation between two working surfaces in contact with each other. The most common in the car are ball, roller, needle, tapered and plain bearings (bimetallic inserts).

Plain bearings are support or guide of a mechanism or machine in which friction occurs when sliding mating surfaces. Plain bearing is a housing, which has a cylindrical bore into which an anti-friction liner or sleeve and a lubricating device are inserted. There is a lubricant-filled gap between the shaft and the bearing bush hole, which allows the shaft to rotate freely.

Four-wheel drive is the design of a car's transmission, when the torque generated by the engine is transmitted to all wheels. AWD (All Wheel Drive) and 4WD designations should be distinguished, because, contrary to popular belief, they are not the same thing: AWD means permanent or automatically connected all-wheel drive, and 4WD means four-wheel drive, connected and disconnected manually.

Half shaft (Chapter 5) is a shaft, which is designed for transmitting torque from the main transmission to the wheels of the car.

Piston pin (Chapter 4) is a rod, which is designed for connecting the piston to the upper head of the connecting rod.

Ignition order (Chapter 4) is the order of ignition of the fuel-air mixture inside the cylinders of the internal combustion engine.

Direct current is the directed movement of electric charges, which does not change in magnitude and direction.

Maximum allowable value - the value of the geometric or physical indicator of the part, upon reaching which further operation of the part is impossible or unsafe. The part must be replaced with a new one.

Fuse is a device, which breaks the electrical circuit when the current is exceeded and thus prevents damage to the elements of the electrical circuit.

Drive shaft (Chapter 5) is any shaft, which is used for transmitting torque.

Suspension breakdown is a situation when the suspension spring due to the impact on the obstacle is compressed to the limit. This impact is transmitted to the rubber stops, and through them - to the car body elements. Often the suspension cannot withstand such overloads and breaks down.

Circuit conductivity is the inverse of the resistance in an electrical circuit. It characterizes the closed state of the circuit.

Bleeding air from the hydraulic system is the process of removing air from the elements of the hydraulic system (brakes, clutch, cooling, steering wheel booster, etc.) through specially designed fittings or valves.

Gasket is any sealing material between two metal parts, which is designed for sealing the fit of surfaces.

Anti-burr additive is a coating, which reduces the risk of metal burrs in threaded joints exposed to high temperatures (e.g. bolts of car exhaust pipes).

Radial play - play of the part in the radial direction relative to the axis of rotation.

Radiator (Chapter 4) is a heat dissipation device, heat exchanger. In the engine cooling system, the radiator is designed for transferring heat from the coolant to the atmosphere.

Camber (camber, from the English. Camber angle) - the angle between the vertical and the plane of rotation of the wheel. Camber is considered negative if the wheels are upside down, and positive if upside down.

Transfer case (Chapter 5) is the unit for distributing the torque from the engine to several drive mechanisms. In most cases this also increases number of transfers in transmission.

Cylinder bore boring - increasing the inner diameter of the cylinder bore by machining to the repair size (see "Repair size").

Grinding is the process of renewing the seat surfaces of the valves and their seats in the cylinder head.

Adjusting washers are washers of a certain thickness that are designed for adjusting the geometric parameters of the mechanism (gaps, beats, etc.).

Voltage regulator (voltage stabilizer) is an electrical device, which receives power from an external power supply and outputs a voltage, which is independent of the supply voltage (provided that the supply voltage does not exceed the permissible limits).

Relay is an electrical device, which is designed for closing and opening high-current circuits that are controlled by small currents.

Repair size - a standardized size, increased relative to the nominal, used in the overhaul of a particular unit (for example, a piston-cylinder liner system). Depending on the degree of increase in size relative to the nominal, the first, second, third, etc. repair sizes are distinguished with a certain step (for example, 0.5 mm).

LED is a semiconductor device, which emits light when an electric current is passed through it.

Spark plug (chapter 10) is a device for igniting сfuel and air mixture in the most various heat engines. Spark plugs are used in gasoline internal combustion engines. Ignition of the fuel-air mixture is performed by an electric discharge with a voltage of several thousand or tens of thousands of volts, occurring between the electrodes of the candle. The spark plug is triggered on each cycle, at a certain moment of engine operation.

Free play - the amount of travel before the start of action, due to the weakening of the connections of rods or other elements of the mechanism. For example, the brake pedal free play is the distance that the brake pedal travels before the brake mechanisms begin to operate.

Monograde Oil (Chapter 4) is an engine oil, which meets the requirements of more than one viscosity level according to the SAE classification (Society of Automotive Engineers) (see viscosity levels according to SAE). It can be used in a more limited temperature range than oil with two viscosity levels.

Charging system is a system, which is designed for charging the car battery.

Starting system (Chapter 10) is a system, which is designed for starting an internal combustion engine by forcibly rotating the crankshaft with an electric motor (starter).

Fuel vapor trapping system is a system, which is designed for trapping fuel vapors from the power supply system and preventing them from entering the atmosphere.

Engine control system is an electronic system, which is designed for controlling the processes of intake of fuel-air mixture, ignition and exhaust gases in the internal combustion engine.

Resistance is a quantity that characterizes the properties of a conductor.

Starter (in an internal combustion engine) is a device, which spins the crankshaft in order to start the engine.

Degree of compression is the ratio of the volume of the piston space above the piston at the bottom dead center (BDC) to the volume of the cylinder piston space at the position of the piston at the top dead center (TDC), i.e. to the volume of the combustion chamber. The concept of degree of compression shall not be confused with the concept of compression, which means (with a certain structurally determined compression ratio) the maximum pressure created inside the cylinder when the piston moves from BDC to TDC (for example: degree of compression - 10: 1, compression -14 atm).

Lock washer is a washer, which is placed under a nut or bolt head and prevents them from turning away spontaneously.

Retaining ring is an elastic ring, which is used for preventing the movement of cylindrical parts and shafts. The inner retaining ring is mounted in a groove in the housing. The outer retaining ring is mounted into the groove in the outer cylindrical surface of the axis.

Convergence - the angle between the direction of movement and the plane of rotation of the wheel. Very often they talk about the total convergence of two wheels on the same axle. In some cars, the toe-in of both the front and rear wheels can be adjusted.

Fuel-air mixture (Chapter 4) is a charge, which consists of a mixture of fuel and air supplied to the cylinder of an internal combustion engine.

Turbocharger (gas turbine blower) is a device, which uses the energy of exhaust gases for injecting air or fuel-air mixture into the internal combustion engine. For low-power (automobile) engines, turbochargers with a centrifugal turbine are used. For high-power engines (tractor, diesel, ship) - turbochargers with an axial turbine are used. The compressor is always centrifugal, because the axial compressor has a more complex design and a tendency to surge.

Valve opening angle (Chapter 4) is the position of the crankshaft at which the valve opens (inlet or outlet).

King pin lateral inclination of the kingpin is the angle between the vertical and the projection of the axis of the steering mechanism on the transverse plane of the vehicle. This angle allows the steering wheels to self-align with the weight of the vehicle.

The carbon filter is the main component of the fuel vapor recovery system, consisting of activated carbon granules designed to trap fuel vapors from the fuel system and prevent them from entering the atmosphere.

O-ring is a sealing element in the form of a ring, which is made out of an elastic material (e.g. rubber).

Thrust washer is a washer, which is installed between two components that are located on the axis (shaft) in order to provide the required value of the axial clearance.

Honing is a type of abrasive processing of materials using honing heads (hones). It is mainly used for processing internal cylindrical holes (from 2 mm) by combining the rotational and reciprocating movement of the hone with sliding abrasive bars fixed on it with abundant irrigation of the treated surface with cutting fluid. One of the types of finishing and finishing cutting. Allows you to get a hole with a deviation from cylindricity up to 5 microns and a surface roughness Ra = 0.63 / 0.04.

Timing chain (Chapter 4) is a chain, which is designed for synchronous transmission of rotation from the crankshaft to the camshaft (s) of the engine.

Cetane number (Chapter 4) is a characteristic of the flammability of diesel fuels, which determines the period of delay of ignition of the mixture (the period of time from the injection of fuel into the cylinder to the beginning of its combustion). The higher the cetane number, the smaller the delay and the calmer and smoother the fuel-air mixture.

Cylindrical spring (coil, helical) is a cylindrical spiral, which is made out of elastic wire of various sizes. it is designed for accumulating and absorbing mechanical energy. This type of string is widely used in car design.

Frequency of rotation - a value that characterizes the speed of rotation of the body (shaft). It is measured in the number of revolutions per unit of time.

Ball bearing is a bearing, which consists of two rings (inner and outer) out of hardened steel and a set of balls between them.

Connecting rod (chapter 4) is an element of the crank mechanism, which is intended for transferring of mechanical energy from the piston to the crank (crankshaft).

Connecting rod inserts are bimetallic inserts that are plain bearings that are installed in the lower head of the connecting rod to reduce friction between the connecting rod and the crankshaft.

Shimmy (wobbling) - the effect of a motorcycle or car front wheel beating at speed, causing the steering wheel to vibrate and the vehicle to "wobble" from side to side. Shimmy is dangerous because it occurs not at low, but only at high speeds. It requires immediate action from the driver, but even these do not guarantee success.

CV Joint (Chapter 5) is a mechanical device, which transmits high torque at angles of rotation up to 70 ° relative to the axis. It is used in systems of a drive of wheels of cars with an independent suspension bracket on half shafts of forward and, less often, rear wheels.

A caliper is a high-precision measuring device designed to measure internal and external diameters.

Electrolyte (Chapter 10) is a solution or molten metal, which conducts electric current. In the automotive business, a solution of sulfuric acid used in a battery for a chemical reaction, the energy of which is converted into electrical energy.

Electronic control unit (Chapter 4) is a device, which controls the electronic components of a system (e.g., engine ignition).