O-RING SEAL

O-Ring seal is a common seal .

It is for use  in machine design.

O-ring seal can be use in static application such as cover or pin. If the machine parts being seal move relative to one another, the o-ring acts like a dynamic seal.

Easy to craft , reliable , inexpensive.

A packing device .

Commonly moulded in one piece from elastometric material.

Also use to offer structural support ,absorb energy, transmit energy, transmit fluid and seal fluid.

O-ring acts like a seal just by blocking any leaking of gas or liquid between two close mating surface.

O-ring are utilize to keep the air or fluid in/out of distinct space.

It is use in under water camera in order to keep the water out.

SCUBA regulator use O-rings to avoid air from moving out.

Also,use in automobile parts ,cups , drive , belts,body jewellery.

O-RINGS are made from rubbers, metals and plastics.

STATICS v/s DYNAMICS SEALING

O-ring also called Toric joint

If the pressure of fluid contain is not greater than the mating stress of o-ring ,then sealing is completed.

To meet the explicit performance requirement of special seals like”ENERGIZED HYDRULIC SEALS” and ”OIL SEEDS” are available.

VACCUM APPLICATION

In vaccum system that must be immerse in liquid nitrogen utilise indium o-ring.

Rubber become brittle and hard at lower temperature.

High vaccum system make use of nickle or copper o-ring.

SIZES

O-rings come in a variety of sizes. Society of Automotive Engineers (SAE) Aerospace Standard 568 (AS568)[15] specifies the inside diameters, cross-sections, tolerances, and size identification codes (dash numbers) for O-rings used in sealing applications and for straight thread tube fitting boss gaskets. British Standard (BS) which are imperial sizes or metric sizes. Typical dimensions of an O-ring are internal dimension (id), outer dimension (od) and thickness / cross section (cs)

Metric O-rings are usually define by the internal dimension x the cross section. Typical part number for a metric O-ring – ID x CS [material & shore hardness] 2x1N70 = defines this O-ring as 2mm id with 1mm cross section made from Nitrile rubber which is 70Sh. BS O-rings are define by a standard reference.

DIFFERENT TYPES OF ENGINE

WANKEL ENGINE

 

 

 

 

 

 

 

 

DIFFERENT TYPES OF ENGINE

Basically, different types of engine are external combustion engines and combustion engines.

(i). External combustion engine:

In an external combustion engine, the combustion of fuel takes place outside the engine. Example: steam engine.

(ii). Internal combustion engine:

In an internal combustion engine, the combustion of fuel takes place inside the engine. Two-stroke and four-stroke petrol and diesel engine are examples of internal combustion engine.

There are different types of internal combustion (I.C.) engine and their classification depends upon various basis.

 

The I.C. engines are classified on the following basis:

1. Types of Design

(i). Reciprocating engine:

In a reciprocating engine, there is a piston and cylinder, the piston does reciprocate (to and Fro) motion within the cylinder. Due to the reciprocating motion of the piston, it’s called internal-combustion engine . 2 stroke and four-stroke engines are the common samples of internal-combustion engine.

(ii). Rotary engine:

In the rotary engine, the rotor does rotary motion to produce power. There is no reciprocating motion. A rotor is present within the chamber which does rotation inside a chamber. Wankel rotary engine, turbine engines are the rotary types of engines.

2. Types of Fuel Used

On the basis of types of fuel used, the engine is classified as a petrol engine, diesel engine, and gas engine.

(i). Petrol engine:

The engine which uses petrol for its working is called a petrol engine.

(ii). Diesel engine:

The engine which uses diesel for its working is named diesel.

(iii). Gas engine:

An engine using gas fuel for working is called a gas engine.

3.Cycle of Operation

On the basis of the cycle of operation the engine types are:

(i). Otto cycle engine:

These types of engine work on the Otto cycle.

(ii). Diesel cycle engine:

The engine working on the diesel cycle is called a diesel cycle engine.

(iii). Dual cycle engine or semi-diesel cycle engine:

The engine that works on both diesel also as Otto cycle is named a dual cycle engine or semi diesel cycle engine.

4.Number of Strokes

On the basis of the number of strokes, the types of engine are:

(i). Four Stroke Engine:

it’s an engine during which the piston moves fourfold I .e.2 upward (form BDC to TDC) and a couple of downward (from TDC to BDC) movement in one cycle of the power stroke is called four-stroke engines.

(ii). Two Stroke Engine:

The engine during which the piston does twice motion i.e. one from TDC to BDC and other from BDC to TDC to supply an influence stroke is named two-stroke engines.

(iii). Hot spot ignition engine:

this sort of engine isn’t in practical use.

5. Type of Ignition

On the idea of ignition, the engines are classified as:

(i). Spark ignition engine (S.I. engine):

In spark-ignition engine there’s a sparking plug which is fitted at the engine head. The sparking plug produces spark after the compression of the fuel and ignites the air-fuel mixture for the combustion. The petrol engines are spark-ignition engine.

(ii). Compression ignition engine (C.I. engine):

In Compression ignition engine there’s no sparking plug at the plate. The fuel is ignited by the warmth of the compressed gas. The diesel engines are compression ignition engine.

6. Number of Cylinders

On the basis of the number of cylinders present in the engine, the types of engine are:

Different Types of Engine

(i). Single-cylinder engine:

An engine which consists of single-cylinder is named single-cylinder engine. Generally the single-cylinder engines are utilized in motorcycles, scooter, etc.

(ii). Double cylinder engine:

The engine which consists of two cylinders is named double cylinder engine.

(iii). Multi-cylinder engine:

An engine which consists of quite two cylinders is named multi-cylinder engine. The multi-cylinder engine may have three, four, six, eight, twelve and sixteen cylinder.

7. Arrangement of Cylinders

On the basis of the arrangement of cylinders the engines classification is:

(i). Vertical engine:

in vertical engines, the cylinders are arrang in vertical position as shown within the diagram.

(ii). Horizontal engine:

In horizontal engines, the cylinders are place horizontal position as shown within the diagram given below.

(iii). Radial engine:

The rotary engine is reciprocating type combustion engine configuration during which the cylinders radiate outward from a central crankcase just like the spokes of a wheel. When it’s view from the front,

it resembles a style star and is name a ‘star’ engine.

Before the gas turbine engine does not become predominant,

it is commonly used for aircraft engines.

(iv). V-engine:

In v sorts of engine,

the cylinders are place in two banks having some angle between them. The angle between the two banks is kept as small as possible to prevent vibration and balancing problem.

(v). W type engine:

In w type engines, the cylinders are arrange in three rows such it forms W type arrangement. W type engine is form when 12 cylinder and 16 cylinder engines are produce.

(vi). Opposed cylinder engine:

In opposed cylinder engine, the cylinders are place opposite to every other. The piston and therefore the rod show identical movement. It runs smoothly and has more balancing. The size of the opposed cylinder engine increase due to its arrangement.

8. Valve Arrangement

According to the valve arrangement of the inlet and valve in various positions within the plate or block, the car engines are classified into four categories. These arrangements are name as ‘L’, ‘I’, ‘F’ and ‘T’. It is easy to recollect the word ‘LIFT’ to recall the four-valve arrangement.

(i). L-head engine:

In these sorts of engine, the inlet and exhaust valves are arrange side by side and operate by one camshaft. The cylinder and combustion chamber forms an inverted L.

(ii). I-head engine:

In I-head engines, the inlet and exhaust valves are located within the plate. one valve actuates all the valves. These sorts of engine are mostly utilize in automobiles.

(iii). F-head engine:

it’s a mixture of I-head and F-head engines. In this, one valve usually inlet valve is within the head and therefore the valve lies within the engine block. Both the sets of valve are operate by the only camshaft.

(iv). T-head engine:

In T-head engines, the inlet valve located at one side and therefore the valve on another side of the cylinder. Here two camshafts are required to work, one for the inlet valve and the other one is for the valve.

9. sorts of cooling

On the idea of sorts of cooling, the engines are classified as:

(i). Air-cooled engines:

In these engines,

the air is use to chill the engines.

In air-cooled engines,

the cylinder barrels are separate and metal fins are use which provide a radiating area that increase cooling.

The air-cooled engines are generally utilize in motorcycles and scooters.

(ii). Water-cooled engines:

In water-cooled engines,

the water is employe for the cooling of the engine.

Water-cooled engines are utilize in cars, buses, trucks and other four-wheeled vehicles, heavy-duty automobiles.

An anti-freezing agent is add , within the water to stop it from freezing during weather.

Every water-cooled engines has radiator for the cooling of predicament from the engine.

 the I.C engine is additionally classified :

1. Speed:

On the idea of speed, the kinds of engines are:

(i). Low-speed engine

(ii). Medium-speed engine

(iii). High-speed engine

2. Method of fuel injection system

On the idea of method of fuel injection system the engines are classified as:

(i). Carburettor engine

(ii). Air injection engine

(iii). Airless or solid injection engine

3. Method of Governing

(i). Hit and miss governed engine:

it is a type of engine in which the entry of the fuel is control by the governor. It controls the speed of the engine by isolating the ignition and fuel supply of the engine at very high speed.

(ii). Qualitatively governed engine

(iii). Quantitatively governed engine

4. Application

(i). Stationary engine:

Stationary engine is an engine in which its framework doesn’t move.

it’s wont to drive immobile equipment like pump, generator, mill or factory machinery etc.

(ii). Automotive engine:

These are the kinds of engines which utilize in the automobile industries.

For e.g:

petrol engine, diesel, internal-combustion engine are combustion engines falls within the category of automotive engine.

(iii). Locomotive engine:

The engine which is used in trains are called locomotive engines.

(iv). Marine engine:

The engine which used in marines for boat or ship propulsion is named marine engine.

(v). Aircraft engine:

The engines which use in aircraft is called aircraft engine.

Radial and turbine engines is use in aircraft propulsion.

Also read: WANKEL ENGINE

 

WANKEL ENGINE

wankel-engine

It works on a similar principle on the otto cycle.

It consists of three lobes rotor, casing, spark plug, suction, and exhaust ports.

The rotor of the engine is driven eccentrically in the casing in such a way that there are three separate volume trapped between the rotor and casing.

 

The volume trapped in each lobe performs the function of suction, compression, ignition, combustion, expansion, and exhaust processes.

Therefore,

we get three power strokes in one revolution of the rotor

WANKEL ENGINE

https://youtu.be/josJhz8VS8A

In the case of a four-stroke I.C. engine, we get one power stroke in two revolutions of the crankshaft,

Thus,

the Wankel engine develops six times the power for the same capacity of cylinder compared to reciprocating I.C .engines.

Intake:-

When a tip of the rotor passes the intake port, a fresh mixture starts getting into the primary chamber. The chamber draws fresh air until the second apex reaches the intake port & closes it. At the instant, the fresh air-fuel mixture is sealed into the primary chamber & is being removed for combustion.

Compression:-

The chamber one(between corner 1 to corner 2) containing the fresh charge gets compressed

to the form of the engine by the time it reaches to sparking plug.
While this happens, a replacement mixture starts getting into the second chamber(between corner 2 to corner 3).

Combustion:-

When the sparking plug ignites, the highly compressed mixture expands explosively. The pressure of expansion pushes the rotor within the forward direction. This happens until the primary corner passes through the exhaust port.

Exhaust:-

As the peak OR corner 1 passes the exhaust port, the recent high-pressure combustion gases are liberal to effuse of the port.
As the rotor continues to maneuver, the quantity of the chamber goes on decreasing forcing the remaining gases out of port. By the time the corner 2 closes the exhaust port, corner 1 passes by the intake port repeating the cycle.
While the primary chamber is discharging gases, the second chamber(between corner 2 to corner 3) is under compression. Simultaneously, chamber 3(between corner 3 to corner 1) is drawing a fresh mixture.
This is the sweetness of the engine – the four sequences of the four-stroke cycle, which occur consecutively during a piston engine, occur simultaneously within the Wankel engine, producing power during a continuous stream.

What is carburetor?

Maximum efficiency

 

 

 

Maximum efficiency

Ideal engine has a maximum efficiency,

If a heat engine goes through fixed thermodynamics stage of a specificed process,

 

MAXIMUM EFFICIENCY

four main parts:η

  • Insulated – non conducting stand (the transfer of energy is not possible )
  • Hot reservoir– heat capacity should be infinite.

Because , After taking  any energy from it, the temperature of reservoir should be constant .

  • The reservoir in which infinite heat capacity will be conducting at high temperature is called to be cold reservoir.
  •  Cylinder  should be kept for working substances .

Cylinder wall should be non-conductive so that heat transfer is impossible .but base should be conducting .

MAXIMUM EFFICIENCY

For this , first place the cylinder on the hot reservoir since the temperature of reservoir is higher than the temperature of gas, the heat flows from the heat reservoir to the gas .Due to which the gas start to expands .

Since due to heat transfer gas is expanding therefore the temp of gas remain constant

This process is called Isothermal expansion.

as the gas expand , the volume of gas increase and pressure decrease .

In next step , take off the cylinder from the hot reservoir and place it on the insulating stand , when doing so, the gas is confined to the non-conducting wall.

Now let piston rise slowly upward .

Due  to which the gas continue to expand .But this time the gas is not getting any heat to expand .such expansion called Adiabatic expansion.

Since this expansion is taking place without heat .

The temperature of gas starts to decrease .Due to this expansion ,the volume of gas also increase and pressure decrease

In next step, lift the cylinder from the stand and place it on the cold reservoir , now pressure the piston downwards which causes compression of gas.

In this way the gas compresses at the same constant temperature .this called Isothermal compression

Due to this compression the volume of gas decreases and pressure increase

In final stage , cylinder keep on stand again and pressure piston downward

But now there is no cold reservoir to absorbs the heat getting produced extra.

Therefore , the temperature of gas start increase . this compression is called Adiabatic compression .

Pressure the piston until the temperature of gas rises back to equal that of the hot reservoir . This decrease the volume of the gas and increase the pressure

At the end of this step , the gas return to its initial stage .

This complete cycle is called the carnot cycle .The engine work on it ,is called carnot engine.

η =1-T1/T2

The efficiency depend on the temperature of both reservoir.

If  T1 is  ∞ kelvin and  T2 is 0 kelvin

Either rise the temperature of hot reservoir to ∞ kelvin or low down the temperature of reservoir to 0 kelvin .

In both cases,the efficiency will be 100%.