Sunday 18 June 2023

MACHINE GEARS(TRANSMISSION SYSTEM)

 There are many types of GEARS such as spur gears, helical gears, bevel gears, worm gears, gear rack so many .These can be broadly classified by looking at the positions of axes such as parallel shafts, intersecting shafts and non-intersecting shafts.


If we are discussing about types of gears then it can be classified based on the axis of the shaft, on the basis of the velocity of the gear, on the basis of types of gearing and the last is on the basis of the position of teeth on gear surfaces.



If you talk about the transmission system on vehicle, you surely need to also discuss car gears. Gears are an important component in the engine that makes the vehicle move. Along with its development, the types of gears on cars are increasingly diverse. To find out more about the types and functions of car gears, see the explanation below.


All of us will learn to drive in a car with manual transmission. As driving instructors, we always find that before teaching how to use something, it’s often beneficial to provide a basic understanding of how it works. In this tutorial, we shall provide a basic example of how manual car gears work.


Move the gearstick into neutral in car gears. This is the middle position that feels free when moved from side to side. The vehicle is considered out of gear when:[5]

The gearstick is in the neutral position, and/or

The clutch pedal is fully depressed.

Don’t try to use the gearstick without having the clutch pedal depressed, because it simply won't work.

Monday 19 November 2018

FORMING

DEFINITION  :
Image result for ANALYSIS OF METALS FORMING PROCESS         The process of the loss of stability is analysed for sheet metal subjected to biaxial tension when the ratio of the principal stresses 
0.5 ⩽ σ21⩽ 1. The loss of stability manifests itself by a groove running in a direction perpendicular to the larger principal stress. In this groove local strains begin to concentrate gradually. In the initial stage of the process the deepening of the groove is associated with a gradually fading strain in the regions adjacent to the groove. This fading strain attains a certain limiting value ...

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Roll forming, also spelled rollforming, is a type of rolling involving the continuous bending of a long strip of sheet metal (typically coiled steel) into a desired cross-section. The strip passes through sets of rolls mounted on consecutive stands, each set performing only an incremental part of the bend, until the desired cross-section (profile) is obtained. Roll forming is ideal for producing constant-profile parts with long lengths and in large quantities.
How the open die forging process affects the crystal structure

Forging defined

At its most basic level, forging is the process of forming and shaping metals through the use of hammering, pressing or rolling. The process begins with starting stock, usually a cast ingot (or a "cogged" billet which has already been forged from a cast ingot), which is heated to its plastic deformation temperature, then upset or "kneaded" between dies to the desired shape and size.
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Advanced Manufacturing Technology Research Group
In close collaboration with academic and industrial partners and with a focus for aerospace, automotive and medical application, the research team carries out fundamental and applied research in the following areas:

  • New flexible and hybrid material forming processes
  • Process modelling and optimisation

  • Material characterisation, constitutive models, formability and fracture
  • Friction stir welding and processing of lightweight materials
  • Tribological behaviour in bulk and sheet forming processes








  • FORGING

    DEFINITION OF Hot forging and cold forging :-
                                   Hot forging and cold forging are two different metal forming processes that deliver similar results. Forging is the process of deforming metal into a predetermined shape using certain tools and equipment—deformation is accomplished using hot,cold, or even warm forging processes.   
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    Cold and Hot Forging: An Overview

    Forging is a metal shaping process in which a malleable metal part, known as a blank, billet or work-piece, is worked to a predetermined shape by one or more processes such as hammering, upsetting, pressing, rolling and so forth. Cold forming is a precision category of forging which does the same thing without heating of the material (room temperature), or removal of material
    hot roll part
    Among all manufacturing processes, forging technology has a special place because it can be used to produce parts of superior mechanical properties with minimum waste of material.
    Forging can be produced at multiple temperature levels. Room temperature (or heat added process) forging is commonly called cold forging. This process is less costly, less heat energy consuming, provides greater dimensional accuracy, and can be very efficient for mass production of small parts (less than 50lbs). The downfall is that it requires much larger pressures to form the metal requiring large machinery and more frequent tool wear .
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     is also important to remember that some technologies are unbeatin Courmayeur in 1909 the family was already renowned among alpinists for the quality of their ice axes. The story goes that old Henry, controversial and always ready to take the mickey, used to convince even the most wary clients of the strength of his tools were by striking them on the huge block of granite outside his workshop. But where did this strength and above all this self confidence come from Precisely from the technique of hot drop forging, exactly the same that produced the blades of the Sword o Damascus and of Toledo, world famous for their superior strength.

    Steel doesn't have the cold and uniform characteristics that we usually give it but is instead groups of molecular chains that line up and distribute themselves according to lines of force that create the strength of the piece of 'iron'. A bit like fibres in wood that we're used to seeing and choosing according to their natural formation to get the best possible stamina. The huge advantage of steel is that it can be shaped to how we want it when it is heated to 'cherry red' temperature (about 950'C). Mantice At this point it can be modified through being beaten to align its fibres according to the lines of force needed to obtain the maximum strength in the direction that 
    we want: for example following the length of an ice axe's blade
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    To summarise: the fibres in steel are internally aligned in a casual sequence, these can be re-aligned which ever direction we want when the steel is heated to a certain temperature and then 'ironed out' by beating it and forcing it into the desired alignment. This operation, followed up by heat treatment (what was once known as 'tempering' that fixed permanently the internal structure), is precisely known as 'hot forging'. It is how the best characteristics and the desired form are obtained from steel. No other process has ever, and ever will, better this one: quiz a specialist in metallurgy an
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    WELDING DEFECT

      Welding Defects can be defined as the irregularities formed in the given weld metal due to wrong or incorrect welding patterns, etc. The defect may differ from the desired weld bead shape, size, and intended quality. Welding defects may occur either outside or inside the weld metal. Some of the defects may be allowed if the defects are under permissible limits but other defects such as cracks are never accepted.
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     Undercut
              Most structural failures originate from weld joint because it is the source of discontinuity or defects. The most visible weld defect we can easily find in visual inspection is undercut, shown in Figure 1 below. Undercut is usually due to overcurrent in electric arc welding. Overcurrent causes wide melting zone in base metal but not enough weld fusion metal to replace the gap. High lapping speed also leaves the gap poorly filled with weld fusion metal and produces undercut 
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    To avoid undercut, welder and welding inspector must observe initial weld lap to see whether the current setting is appropriate. Post welding inspection can be tricky since welder can cover undercut by running another lap using lower grade welding electrode and low current. Undercut is dangerous because it amplifies the stress flow due to reduction in section area and stress concentration of the notch form.

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                Troubleshooting Weld Defects
    Like any portion of the manufacturing or fabrication process, the welding operation is subject to human error from time to time. When weld defects occur as a result of a problem with welding operator's technique or poor equipment settings, it can cause costly downtime and rework, not to mention, frustration. 

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    When a weld defect appears, it's important for welding operators to have the knowledge they need to rectify the situation as quickly as possible. Faster troubleshooting leads to greater opportunities to add value to the welding operation — through increased productivity and quality improvements.

    Cold Cracks in Fillet Welds

                                      Cold Cracks in Fillet Welds

    VARIATIONS OF COLD CRACKS
    Cold cracks are defined as cracks that occur at temperatures of 200-300°C or lower in carbon steel and low-alloy steel welds. Cold cracks can occur in both butt welds and fillet welds; however, this article will focus on those occurring in fillet welds.
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    IC ENGINE

    Green logistics

    Green logistics Definition : - 
                                        Green logistics describes all attempts to measure and minimize the ecological impact of logistics activities. This includes all activities of the forward and reverse flows of products, information and services between the point of origin and the point of consumption.
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    Logistics is the integrated management of all the activities required to move products through the supply chain. For a typical product this supply chain extends from a raw material source through the production and distribution system to the point of consumption and the associated reverse logistics. The logistical activities comprise freight transport, storage, inventory management, materials handling and all the related information processing.







    Saturday 17 November 2018

    ELECTRICAL TRANSPARENCY

     Definition :- 
                               Transparent conducting oxides (TCOs), which have high transparency through the visible spectrum and high electrical conductivity are already being used in numerous applications. ... A thin conducting layer on or in between the glass panes achieves this.
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    The audio speaker represents a robust proof of concept for ionic conductors because producing sounds across the entire audible spectrum requires both high voltage (to squeeze hard on the rubber layer) and high-speed actuation (to vibrate quickly)—two criteria which are important for applications but which would have ruled out the use of ionic conductors in the past.
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    To make the speaker, a membrane of transparent, insulating rubber is sandwiched between two layers of transparent, conductive gel. The electrical connection to the power source is established outside of the active region of the device, where it does not need to be transparent. Credit: Christoph Keplinger, Jeong-Yun Sun...
    Related imageThe traditional constraints are well known: high voltages can set off electrochemical reactions in ionic materials, producing gases and burning up the materials. Ions are also much larger and heavier than electrons, so physically moving them through a circuit is typically slow. The system invented at Harvard overcomes both of these problems, opening up a vast number of potential applications including not just biomedical devices, but also fast-moving robotics and adaptive optics.
    Related image "It must seem counterintuitive to many people, that ionic conductors could be used in a system that requires very fast actuation, like our speaker," says Sun. "Yet by exploiting the rubber layer as an insulator, we're able to control the voltage at the interfaces where the gel connects to the electrodes, so we don't have to worry about unwanted chemical reactions. 
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    The input signal is an alternating current (AC), and we use the rubber sheet as a capacitor, which blocks the flow of charge carriers through the circuit. As a result, we don't have to continuously move the ions in one direction, which would be slow; we simply redistribute them, which we can do thousands of times per second."
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    Power Minister Launches App For Transparency In Due To Gencos From Discoms
                    The power ministry on Tuesday launched a web application that seeks to bring transparency in dues of power generators from power distribution companies. The app—christened Prapti (payment ratification and analysis in power procurement for bringing transparency in involving of generators—will bring transparency in the payments due to power producers from power distribution companies, power minister R K Singh said. The minister said health of power generator companies was a concern. “This app will go a long way in addressing it. Prompt payments will make generators healthier,” he said, adding this will also enable the banks to recover dues in time.

    TRANSPARENCY

    Transparency is woven into the fabric of everything we do.

     Image result for electrical transparencyInformation about our investment philosophy, process and fee structure is freely available, as are performance data for your portfolio. We share the underlying rationale for our recommendations, as well as your other options. There are no “black boxes,” and we strive to make our regular reporting clear, straightforward and easy to understand.

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    In addition to routine reports and our client portal, you’ll find that we frequently share market observations, analysis and insights through our own client communications. We hold client events to encourage discussion and dialogue, and we love to hear from clients whenever they want to talk or have a question.
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    We practice information sharing and open communication because we believe that informed clients are essential to effective relationships and long-term financial success.

    ACTIVE ELECTRICALLY CONTROLLED SUSPENSION

    Definition :-
                              From Wikipedia, the free encyclopedia. Active suspension is a type of automotivesuspension that controls the vertical movement of the wheels relative to the chassis or vehicle body with an onboard system, rather than in passive suspension where the movement is being determined entirely by the road surface.
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    With respect to weight, energy consumption, and cost constraints, hydro-active suspension system is a suitable choice for improving vehicle ride comfort while keeping its handling. The aim of sensors selection is determining number, location, and type of sensors, which are the best for control purposes.
    Image result for active electrically controlled suspension    Selection of sensors is related to the selection of measured variables (outputs). Outputs selection may limit performance and also affect reliability and complexity of control systems. In the meanwhile, hardware, implementation, maintenance, and repairing costs can be affected by this issue. In this study, systematic methods for selecting the viable outputs for hydro-active suspension system of a passenger car are implemented. 
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    Having joint robust stability and nominal performance of the closed loop is the main idea in this selection. In addition, it is very important to use these methods as a complementation for system physical insights, not supersedes. So, in the first place the system is described and the main ideas in ride comfort control are addressed. An 8 degrees of freedom model of vehicle with passive suspension system is derived and validated. Both linear and nonlinear models of the car which is equipped with hydro-active subsystem are derived. 

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    After selecting the outputs, for benefiting from minimum loop interactions, the control configuration is systematically determined. The main goal of selecting control configuration is assessing the possibility of achieving a decentralized control configuration. 
    Related imageFinally, the system behavior is controlled by a decentralized proportional–integral–differential (PID) controller. The results indicate the efficiency of the controlled hydro-active suspension system in comparison with the passive system.


    BUILD 7128 – SUBFRAME AND SUSPENSION

    Earlier installments of Build128 have taken you through, step-by-step, in how we perform some of the processed we undertake as we construct our cars. From the tub chassis, to the exterior panels, to the preparation and paint stages of the build.   
    As with our last instalment – the koenigsegg engine t– we’re going to talk in coming instalments about why we do things the way we do, rather than concentrating on how.
    Related image It’s one thing to tell you that a guy screws a part in to point ‘A’ on the chassis. It’s a different thing, and a more imhportant thing, to tell you what that part does and why it exists.To our subframe and suspension, then…..At this point in production, the panels have been removed from the car at the end of Station 2 and are sent to Station 3/4 for preparation, paint and polishing. 
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    While all that’s happening, the tub chassis moves along to Station 5, at which point the chassis is prepared to receive the engine, gearbox and front/rear subframes and suspension.Technicians on Station 5 prepare the chassis for the subframe by fitting a lot of the ancillary items to the chassis. In the photo below, you can see that heat-shields have been fitted, along with the battery and other fittings
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    Michelin’s Active Wheel technology has been around for the past couple of years but actual applications of the electronic powertrain and handling management system are still hard to come by. Over the years the technology has been showcased in a number of concepts, and at this week’s Paris Motor Show Michelin unveiled the latest generation of its innovative design in the new Volage  electric roadster concept from Monaco’s Venturi.
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    The Active Wheel is essentially a standard wheel that houses a pair of electric motors. One of the motors spins the wheel and transmits power to the ground, while the other acts as an active suspension system to improve comfort, handling and stability. The system is designed for battery or fuel-cell powered electric vehicles, and the technology is such that a vehicle equipped with it will no longer need any gearbox, clutch, transmission shaft, universal joint or anti-roll bar.
    Active Wheel’s compact drive motor and integrated suspension system has also enabled designers to fit a standard brake disc between the motors, which means the braking, drive and suspension components are all fitted within the single wheel.Depending on the amount of power or type of usage desired, a given vehicle may feature up to four Active Wheels for AWD traction.Related image The system also allows torque from the motors to be electronically controlled for each individual wheel independently. The results are similar to the effects of an active differential, allowing a vehicle with Active Wheel technology to make much faster turns in poor conditions than traditional shaft-driven vehicles.For the suspension, an electric motor controls an actuator connected to a damping system with varying levels of firmness. This unique system features extremely fast response time—just 3/1000ths of a second and all pitching and rolling motions are automatically corrected.Image result for active electrically controlled suspension