Worm drive

Worm drive:-

A worm drive is a gear arrangement in which a worm (which is a gear in the form of a screw) meshes with a worm gear (which is similar in appearance to a spur gear, and is also called a worm wheel). The terminology is often confused by imprecise use of the term worm gear to refer to the worm, the worm gear, or the worm drive as a unit.
Like other gear arrangements, a worm drive can reduce rotational speed or allow higher torque to be transmitted. The image shows a section of a gear box with a worm gear being driven by a worm. A worm is an example of a screw, one of the six simple machines.

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MAGNETIC BEARING

ACTIVE MAGNETIC BEARING :-

Active magnetic bearing is a bearing which supports a load using magnetic levitation.

Magnetic bearings support moving machinery without physical contact, for example,they can levitate a rotating shaft and permit relative motion without friction or wear. 

In active magnetic bearings (AMB) a stable equilibrium is achieved by means of one or more control loops.

The use of control loop for maintaining the gap between the shaft and bearing differentiate the active magnetic bearings (AMB) from passive ones.

They are in service in such industrial applications as electric power generation and petroleum refining e.t.c.

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Rack and Pinion steering system

Rack and Pinion steering system

The Rack and Pinion steering system is the most common system found mostly in modern vehicles. It employs a simple mechanism. The parts of this system are steering column, pinion gear, rack gear, tie rods, kingpin. The circular motion of the steering wheel is transmitted to the pinion gear through the steering column and universal joint. The pinion is meshed with arack which translates the circular motion into linear motion thus providing the necessary change in direction. It also provides a gear reduction, thus making it easier to turn the wheels. This system is preferred because of its compactness, efficiency, ease of operation. But at the same time it gets easily damaged.

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Compound gears

A compound gear is a number of gears fixed together. Consequently, they rotate at the same speed. An example can be seen below.

The gears that make up a compound gear usually differ in size and have a different number of teeth. This is useful if there is a need to speed up or slow down the final output.

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The Most Powerful Diesel Engine in the World!

The Most Powerful Diesel Engine in the World!
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The Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel engine is the most powerful and most efficient prime-mover in the world today. The Aioi Works of Japan's Diesel United, Ltd built the first engines and is where some of these pictures were taken. It is available in 6 through 14 cylinder versions, all are inline engines. These engines were designed primarily for very large container ships. Ship owners like a single engine/single propeller design and the new generation of larger container ships needed a bigger engine to propel them. The cylinder bore is just under 38" and the stroke is just over 98". Each cylinder displaces 111,143 cubic inches (1820 liters) and produces 7780 horsepower. Total displacement comes out to 1,556,002 cubic inches (25,480 liters) for the fourteen cylinder version.

Some facts on the 14 cylinder version:

Total engine weight: 2300 tons (The crankshaft alone weighs 300 tons.)

Length: 89 feet

Height: 44 feet

Maximum power: 108,920 hp at 102 rpm

Maximum torque: 5,608,312 lb/ft at 102rpm

Fuel consumption at maximum power is 0.278 lbs per hp per hour (Brake Specific Fuel Consumption) . Fuel consumption at maximum economy is 0.260 lbs/hp/hour. At maximum economy the engine exceeds 50% thermal efficiency. That is, more than 50% of the energy in the fuel in converted to motion. For comparison, most automotive and small aircraft engines have BSFC figures in the 0.40-0.60 lbs/hp/hr range and 25-30% thermal efficiency range.

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Thermoelectrically operated fan using a candle.

Thermoelectrically operated fan using a candle.
( Operate a fan with the candle during power cuts/ villages where there is no power!!) Innovation at its best.
A peltier or tec module is placed between two heatsinks. The lower Bieng the hot side heared by the candle. And the upper bieng cooled by the cpu cooling tower. The heat diffrence between the two surfaces generate electricity (about 5v dependant on the peltier module). The peltier module is then wired up to a motor wich in turn drives the fan blades.

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BHP vs PS

BHP vs PS

There are a number of ways to measure the power that can be generated by a mechanical device like a car. The most popular is brake horsepower or BHP, which is a method of measurement for vehicles without the encumbrance added by connecting devices like the gearbox and transmission system. In comparison, PS is a unit of power in German. Although PS is very popular in Germany and in Europe, it is rarely seen anywhere else.

There are a number of ways to get the brake horsepower of an engine using a number of devices like the De Prony brake. But today, the most prevalent way of measuring the brake horsepower of a vehicle is with the use of a dynamometer. A dynamometer is more accurate and its automated feature makes it a lot more convenient for the one measuring.

It is worth noting that horsepower and PS are not necessarily identical when it comes to values as there is a discrepancy in the value of each unit. One horsepower is the equivalent of 746 Watts while one PS is only 735 Watts. When you compare PS to BHP, you get a coefficient of roughly 0.98

BHP is increasingly becoming more popular all around the world as we begin to adapt standardized units of measuring things. Although PS is still somewhat popular in certain areas of Europe, it is no longer a statutory unit and is largely considered as obsolete. Despite being considered obsolete, it is still used in advertising as a lot of people are still familiar with the term.

No matter what unit is used to measure the power output of a vehicle, it should still give you an adequate idea of the performance of the said vehicle. In most cases, you should not worry yourself to much as you would probably get values with units familiar to you. If you are in a foreign place and the unit used is not the one you are familiar with, you should just keep in mind that you only need to multiply the PS value by 0.98 to get BHP or divide BHP by 0.98 to get the PS value.

Summary:

1. BHP is a way of measuring mechanical power while PS is a standard unit for mechanical power in Germany

2. One unit of PS is equivalent to 0.98 horsepower

3. BHP is widely used while PS is considered obsolete

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DRIVE METHODS

CLASSIFICATION OF VEHICLES BY DRIVE METHOD:

Vehicles can be classified by the position of the engine and drive wheels, and the number of drive wheels:-

1)FF (Front-engine, Front-drive)
Because a FF vehicle does not have a propeller shaft, a spacious interior can be realized, thus achieving excellent comfort.

2) FR (Front-engine, Rear-drive)
Because a FR vehicle has a good weight balance, it excels in controllability and stability.

3) MR (Midship-engine, Rear-drive)
Because a MR vehicle has a good weight balance on the front and rear axles, it excels in controllability.

4) 4WD (4-Wheels Drive)
Because a 4WD vehicle drives with four wheels, it can operate under poor conditions in a stable manner. Its weight is greater than that of other types of vehicles.

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Serpentine belt

A serpentine belt, also known as a multi-vee, poly-v, or multi-rib belt, is a single, continuous belt used to drive multiple peripheral devices in an automotive engine, such as an alternator, power steering pump, water pump, air conditioning compressor, air pump, etc. The belt may also be guided by an idler pulley and/or a belt tensioner (which may be spring-loaded, hydraulic, or manual). The production serpentine belt was manufactured by Hutchinson and first used by Mercedes-Benz on the 1985 190 Series.

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Working parts of a piston.

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Variable Nozzle Turbine(VNT)

With this system, the turbine on the intake side has movable guide vanes that change position to provide optimum flow conditions and a high turbine efficiency rating, throughout the engine speed range. This permits high boost pressure from low engine speeds, and thus a flatter torque curve and higher power output. 

The movable guide vanes are controlled by the engine management system, adjusting gas flow to the turbine to ensure optimum efficiency. The result is that the engine responds instantly to the throttle, providing excellent drivability. 

The turbocharger is cooled by the engine oil.

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Gear cutting

Gear cutting is the process of creating a gear. 
The most common processes include hobbing, broaching, and machining; other processes include shaping, forging, extruding, casting, and powder metallurgy.
Gears are commonly made from metal, plastic, and wood.

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Magneto ignition system

An ignition magneto is a magneto that provides current for the ignition system of a spark-ignition engine, such as a petrol engine. It produces pulses of high voltage for the spark plugs.The use of ignition magnetos is now confined mainly to engines where there is no other available electrical supply, for example in lawnmowers and chainsaws. It is also widely used in aviation piston engines even though an electrical supply is usually available. This is because a magneto ignition system is more reliable than a battery-coil system. People discussing magnetos and coils used in early internal-combustion engines generally used the term "tension" instead of the more modern term "voltage."

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Pushrod IC Engine

An overhead (OHV) engine, also informally called pushrod engine or I-head engine, is a type of piston engine that places the camshaft within the cylinder block (usually beside and slightly above the crankshaft in a straight engine or directly above the crankshaft in the V of a V engine), and uses pushrods or rods to actuate rocker arms above the cylinder head to actuate the valves. Lifters or tappets are located in the engine block between the camshaft and pushrods.The more modern overhead camshaft (OHC) design (still literally overhead valve) avoids the use of pushrods by putting the camshaft in the cylinder head.

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Cooling System in Engine

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Harley Davidson

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Extended Expansion Linkage Engine

EXlink (Extended Expansion Linkage Engine) :
With the goal of taking energy efficiency to a new level, Honda developed its own linkage engine design based on Atkinson’s extended-expansion cycle engine, invented some 130 years ago. The first small engine of its type to be commercially produced, the revolutionary EXlink has an expansion stroke longer than its compression stroke to realize an expansion ratio higher than its compression ratio.

In contrast to a conventional Otto cycle engine, in which the piston strokes are typically of the same length, the EXlink has expansion and exhaust strokes that are longer than its intake and compression strokes. The result is an expansion ratio that is more than 1.4 times higher than the compression ratio, allowing EXlink to offer lower pumping losses and substantially higher thermal efficiency than a conventional engine

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A non-circular gear

A non-circular gear (NCG) is a special gear design with special characteristics and purpose. While a regular gear is optimized to transmit torque to another engaged member with minimum noise and wear and with maximum efficiency, a non-circular gear's main objective might be ratio variations, axle displacement oscillations and more. Common applications include textile machines, potentiometers, CVTs (continuously variable transmissions), window shade panel drives, mechanical presses and high torque hydraulic engines.

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The Pentroof hemi engine

The Pentroof hemi engine. 

HEMI Pros and Cons:

There are many different parts of an engine's design that control the amount of power you can extract from each combustion stroke.
For example:

You want to burn all of the gas in the cylinder. If the design leaves any of the gas unburned, it is untapped energy.

You want the maximum cylinder pressure to occur when the crankshaft is at the right angle, so that you extract all of the energy
from the pressure.

You want to waste as little of the engine's energy as possible sucking air and fuel into the combustion
chamber and pushing exhaust out.

You want to lose as little heat as possible to the heads and the cylinder walls. Heat is one of the things creating pressure in the cylinder, so lost heat means lower peak pressures.

HEMI Advantages:

The last item in the above list is one of the key advantages of the HEMI head versus the flathead engine.

Surface area causes heat loss.

Fuel that is near the head walls may be so cool that it does not burn efficiently.

With a flat head, the amount of surface area relative to volume of the combustion chamber is large.

In a HEMI engine, the surface area is much smaller than in a flat head, so less heat escapes and peak pressure can be higher.

Another factor with a HEMI head is the size of the valves . Since the valves are on opposite sides of the head, there is more room for valves.

The engine design that preceded the HEMI was a wedge-shaped combustion chamber with the valves in line with each other.

In a HEMI engine, valves can be large so the airflow through the engine is improved.

HEMI Disadvantages:

If HEMI engines have all these advantages, why aren't all engines using hemispherical heads?

It's because there are even better configurations available today. One thing that a hemispherical head will never have is four valves per cylinder. The valve angles would be so crazy that the head would be nearly impossible to design. Having only two valves per cylinder is not an issue in drag racing or NASCAR because racing engines are limited to two valves per cylinder in these categories. But on the street, four slightly smaller valves let an engine
breathe easier than two large valves.

Modern engines use a pentroof design to accommodate four valves.

Another reason most high- performance engines no longer use a HEMI design is the desire to create a smaller combustion chamber.
Small chambers further reduce the heat lost during combustion, and also shorten the distance the flame front must travel during combustion. The compact pentroof design is helpful here, as well.

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Spur Gears

Spur Gears:-

Spur gears are the most common type of gears. They have straight teeth, and are mounted on parallel shafts. Sometimes, many spur gears are used at once to create very large gear reductions.

Spur gears are used in many devices that you can see all over like the electric screwdriver, dancing monster, oscillating sprinkler, windup alarm clock, washing machine and clothes dryer. But you won't find many in your car.

This is because the spur gear can be really loud. Each time a gear tooth engages a tooth on the other gear, the teeth collide, and this impact makes a noise. It also increases the stress on the gear teeth.

To reduce the noise and stress in the gears, most of the gears in your car are helical.

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