Posted tagged ‘mechanical engineering’

Wall Climbing Robot (WCR)

September 29, 2011

You would rather hesitate to do the inspection and maintenance in a typically dangerous environment like the exterior of a tall building or a nuclear facility and pray to God to provide for someone else to do the same. Well, consider your prayers answered! A wall climbing Robot is willing to go through the trouble so that you can still keep smiling!

But, the idea of developing a wall climbing robot is always held back by the mighty force of GRAVITY!

And BEWARE. This won’t be an Easy Project for you. But this definitely is a fantastic Mechanical Engineering Seminar Topic, especially if you can demonstrate how it defies gravity.

You need to move against gravity to accomplish the task. Adhesion is what is required primarily, to help keep the robot firmly on to the wall. Reliable adhesion is a major factor in developing a WCR. Once a proper suction is obtained, locomotion is the next step.  It is also equally important to keep the weight as low as possible so that the effort to stick on to the wall is quite low.

Wall climbing robot

Adhesion is achieved by making use of

  1. Suction cups

Suction cups offer excellent grip (almost upto 1 atm). But, the negative aspect of using a suction cup is that it needs a vacuum pump. Since the vacuum pump is bulky and has high power consumption it is rather difficult to accommodate one in a WCR. Moreover, a suction cup would find itself useless when trying to stick to a rough surface.

2.    Electrostatic  chuck (ESC)

ESC achieves controlled adhesion by means of electrostatic forces.

Mobility is achieved by making use of an electric motor.

With these things in mind, I hope you would have got an insight of the Wall Climbing Robot.

 

Ref: http://spectrum.ieee.org/robotics/robotics-software/wallclimbing-robot-spies

Pneumatic paper cup forming machine

September 29, 2011

Pneumatic paper cup forming machine” is a wonderful project topic for mechanical engineering students.

In a pneumatic system, energy is stored in a potential state in the form of compressed air. Working energy is produced in a pneumatic system when the compressed air is allowed to expand. So, in order to do work, a device is required which is able to supply an air tank with sufficient amount of air at a desired pressure. This device usually happens to be a positive displacement compressor.

Advantages of using a pneumatic machine:

1)    Lower cost than Hydraulic Machines

2)    Works on air which is freely available.

3)    Compact when compared with Hydraulic Machines

4)    Energy can be controlled relatively easily using valves.

 

The procedure for the development of the paper cup has been broken down into 5 stages

Stages of development:

1)      Body Sealing

A Cup fan wall shaped sheet of paper should be first sealed so as to obtain a cone shape.

2)      Bottom inserting

Round pieces which serve as the bottom of the cup is inserted into the cone and sealed

3)      Bottom knurling

Knurling of the excess portion of the cone is done

4)      Rim Curling

Rim curling is done to make the cup end curled.

5)      Dispensing

The finished cups are automatically discharged from machine.

Pneumatic paper cup forming stages

Factors to be taken into account while designing the cup:

1)      Bottom diameter

2)      Top diameter

3)      Height

4)      Bottom knurling height

5)      Side sealing width

Note:

For best results double PE coated paper is used in the development of cups. Since, in one side PU coated paper cups the paper becomes softened and the chances for the beverage to leak out are high.

Magnetic Levitation Train

September 29, 2011

Love to turn a 45 minute car ride to an 8 minute blur?

China was the first to country to have an up and running Maglev you could buy tickets to. Back in 1979 the Germans developed the 1st Magnetic levitation (Maglev) train.  The first to overcome the limitation of wheel and rail, because the rail moves entirely without contact!

This is a wonderful topic for your mechanical engineering seminar as well as project if you dare to make a working model.

The functions of the wheel and rail on a normal rail road including support guidance propulsion and braking are accomplished through an electro magnetic levitation and propulsion system. The mechanics have been replaced by electronics. Support Magnets draw the vehicle towards the guide way from below. While, guidance magnets hold’s the vehicle laterally on track. These support and guidance magnets are mounted on both sides of the vehicle along its entire length. An electronic control system ensures that it levitates at a constant height above the guide way. The Maglev train is propelled and braked by a synchronous long stator linear motor. This motor is not located in the vehicle itself but rather in the guide way. It functions on the same principle as a traditional rotating electrical motor, whose stator has been cut open, unrolled and stretched length wise along both sides of the guide way. But, instead of a rotating magnetic field a traveling magnetic field is generated in the windings, one that pulls the vehicle along the guide way without contact.

The guide way can be elevated where it makes ecological sense. in this way it won’t divide the landscape or developed areas and the area beneath the guide way can continue to be used as before. The guide way can be built at ground level to allow easier co location with existing transportation systems. Therefore, the guide way can be adapted to the landscape instead of being the other way round.

Maglev Train

The operation control system controls and safe guards the vehicle’s switches, guide ways and stations along the maglev route. The vehicle communicates with the control system by means of directional radio data transmission. The vehicle’s location is monitored by means of a location reference system integrated into the guide way. The only motor section in operation along the guide way, is the one in which the vehicle is currently traveling. When the vehicle passes from one section to the next, the new motor section is automatically switched on. More power is supplied on gradients and acceleration segments along the route than on flat segments this way the propulsion power is distributed very economically. It is always available exactly where it is needed.

The technology’s success in India could ultimately hinge on a combination public funding and private investments.

 

References:

Latest Updates in Mechanical Engineering

September 25, 2011
01-job-interview-easy selection in interview
  • 1hp=how much rpm

We need Torque to find out.

Apply this formula:

T = HP x 5252
           rpm

T = torque (in lb-ft)
HP = horsepower
5252 = constant
rpm = revolutions per minute

  • which mechanism is used in automobile gearing system

Differential mechanism

  • why different types of sound are produced in different bikes though they say run on SI engine

Engine specifications are different in different manufactures like as bore diameter(cc),ignition timing.Also the exhaust passage take more responsible for sound.

  • why entropy decreases with the increase in temperature?

ds=dQ/T

Entropy is inversely proportional to the temperature so.as temp. increases,entropy decreases

  • What type of metal is used in a propeller

Aluminium,stainless steel,magnesium bronze,NIBRAL(nickel,brass,aluminium)

  • why involute curve used in gear

1) it’s smooth to drive the gear.
2) in gears contact is only point, this type is curve take the more load than normal one

  • How Trains take turns, though there is no any differential

Purpose of the differential is to enable vehicles to take turn, by allowing both the wheel to rotate with different speed. This is required when wheels, like in car, are connected with same axle. Interestingly, wheel in trains are not connected with the axle, they are independent and hence can take turns without ant differential. This is same as how the bullock cart takes turns, without any differential.

  • Why freezer in the fridge is placed in top level?

Because density of cold air is higher than warm air,hence itis placed at top.Cold air comes downward & cool the bottom part.

  • what is more dangerous longitudinal stress or Hoop stress and why?

Hoop stress is more dangerous thanlongitudinal stress, because the dangerous area coming underthe hoop stress is circumferential,while in longitudinal,theaxial area will come under dangerous area will will be lessthan circumferential area.So the hoop stress is more dangerous than longitudinal stress

Mechanical Engineering Interview Questions

September 23, 2011

01-interview-interview tips-mechanical engineering interview-job interview

  • What is Heat rate of a Power plant?

Heat rate is a measure of the turbine efficiency. It is determined from the total energy input supplied to the Turbine divided by the electrical energy output.


  • The highest value of Thermal conductivity is expected for

a.) Solid ice   b.) Melting ice c.) Water d.) Boiling water.

Give the Thermal conductivity value.

Solid Ice – 3.48 W/mK

Melting Ice thermal conductivity value is low because temperature is less.

Water’s Thermal conductivity value is 2.18 W/mK.


  • What is a Hydrostatic system?

Hydrostatics is the study of fluid bodies that are

  • At rest
  • Moving sufficiently slowly so there is no relative motion between adjacent parts of the body

For hydrostatic situations

  • There are no shear stresses
  • There are only pressure forces that act perpendicular to any surface.

It’s a closed loop hydraulic systems. It comprises of motor and pump. Here pump supplies energy to motor and motor gives return energy to pump supply.


  • If you heat a piece of steel with a hole in the center will the diameter of the steel get bigger or smaller?

It gets bigger.

(Example: Always the bearings are heated first for new installation in a shaft.)


  • What is the difference between Blower and Fan?

Fan is an air pushing device. Either Axial or Centrifugal type systems are used to move the air in low pressure. It is rotated by a motor separately.

When the fan is a housing of blades and motor, then it called as Blower. It directs the air in a single path with high pressure.


  • How to find a Ductile-Brittle Transition Temperature in metals?

The point at which the fracture energy passes below a pre-determined point for a standard Impact tests. DBTT is important since, once a material is cooled below the DBTT, it has a much greater tendency to shatter on impact instead of bending or deforming.


  • What is Hydrodynamic Cavitation?

Hydrodynamic cavitation describes the process of vaporization in a constrained channel at a specific velocity.

Bubble generation and Bubble implosion which occurs in a flowing liquid as a result of a decrease and subsequent increase in pressure.

AIMES 2010

September 18, 2011

scaned_005

 

Mangalore, October 22: Association of Integrated Mechanical Engineering Students (AIMES) was inaugurated recently at Srinivas Integrated Campus, Mukka.

After formally inaugurating the Association, Deepak Prabhakar, Senior Manager of Mechanical Department, MRPL said that students need to participate in extracurricular activities to expose themselves to the outer world. Along with computer and technical skills, they should cultivate skills of conversation and communication, he said.

He also advised that student associations should aim at developing overall personality and self confidence of an individual.

In his presidential address Dr. Shreeprakash B, Principal, Srinivas School of Engineering, opined that students should cultivate the habit of personal life-skills, leadership quality, and cultivate the capacity to start self employment.

Vivekananda Huddar, Head of the Mechanical Department, briefed about the objectives of the Association.

President of Association Parivesh Rathod welcomed the gathering and Secretary Pramod proposed the vote of thanks. Tilak E compered the programme.

 

 

Mechatronics / Introduction

September 16, 2011

Mechatronics is a word originated in Japan in 1980s to denote the combination of technologies which go together to produce industrial robots.

A formal definition of Mechatronics is “the synergistic integration of Mechanics and Mechanical Engineering, Electronics, Computer technology, and IT to produce or enhance products and systems.’’

The various fields that make up Mechatronics is shown in Fig

01-what is Mechatronics-Introduction-Mechanical and Eletronics

Examples of such systems are

  • Computers,
  • Disk drives,
  • Photocopiers,
  • Fax machines,
  • VCR,
  • Washing machines,
  • CNC machine tools,
  • Robots, etc.

Today’s modern cars are also mechatronics product with the usage of electronic engine management system, collision detection, global positioning system, and others.

01-mechatronics-design-combination of mechanical and electronics

The concept of mechatronics is very important today to meet the customers’ ever increasing demands and still remain competitive in the global market. Very often a mechanical engineer without the mechatronics background is considered equivalent to a mechanical engineer without the engineering drawing knowledge.

Mechatronics requires thinking products and processes so transverse. Mechatronics is “burst the walls, with a steering matrix. The pilot at the highest level of the enterprise is essential in this context, to afford in front needs to be implemented.

The design should no longer be sequentially: the mechatronics approach requires thinking about the product as a whole (all skill areas at a time) and not by separating the mechanical part, then electronics, then the sensor – actuators and computers at risk to achieve additional cost prohibitive.

01-robot-arm-future-mechatronics

The project manager must master the various areas and not be an expert in one of mechatronics technology: It was necessary to avoid watching the draft with an eye mechanics or electronics. The pilot is here, as elsewhere, the role of a conductor, not a virtuoso.

The phases of integration are sensitive, such that an electronic assembly in a machine shop (or vice versa). There are telescoping and areas of project management and competence, which involves work that is done jointly, to ultimately obtain not a purely mechanical or purely electronic, but a set that combines the advantages of 2, which can not be separated.