Task 1:describe the arrangement and operation of two different kinds of transmissionshafts and coupling, two different kinds of clutch and two different kinds ofbrake. What is a transmission shaft: The transmission is asophisticated mechanism while allowing a car to function at multiple speeds andstill maintaining the engine best performance within the rpm range.Transmission shafts receive and transmit power to the output system and wheels.
Cold extrusion is understood as one of the manufacturing processes for theproduction of automotive transmission shafts. What is the input shaft: The transmission is an essential partof the drivetrain of a vehicle. This is a sophisticated of the shafts and gearsthat enable the controlled application of the power reasoning from the engineto the wheels. The input shaft takes the engine into the gearbox system andwhen a gear is engaged it withstands the torque generated and transmitted tothe output shaft.
Steel forging of the input shafts allows the variant of shapesand resistance needed to ensure reliable transmission system. Set forgeexpertise covers the main manufacturing techniques to produce high-qualityinput shafts for the automotive industry. What is the output shaft: The output shaft is a splined shaft thatis connected to the wheels. On the output shaft between is every pair of gearsin a collar.
This is a round piece that is locked into the splines of theoutput shaft. By being attached to the shaft in this way, the collar rotatewith the shaft, but can slide in different motions along the shaft splines. What is the lay shaft: A lay shaft is an intermediate shaftwithin a gearbox that carries gears, but does not transfer the primary drive ofthe gearbox either in or out the gearbox. Lay shafts are known through the usein car gearboxes, where they were in ubiquitous part of the rear-wheel drivelayout.
With the shift to front-wheel drive. The driving shaft carries theinput power into the gearbox. The driven shaft is the output shaft from thegearbox. The driven shaft is the output shaft from the gearbox. In the cargearboxes are with lay shafts, these two shafts extruded from ends of thegearbox. For gearboxes are generally mounted on a lay shaft may either turnfreely on fixed shaft, or may be part of that then rotates in bearings. What is a clutch: A clutch is a mechanical devicewhich involves and unfastens power transmission especially from the drivingshaft to driven shaft.
Clutches connect and disconnected two rotating shafts.In these devices, on shaft is typically attached to an engine or alternativepower unit while the other shaft provides output power for work. Whiletypically the motions are rotary, linear clutches are also possible. What is a friction clutch: A friction clutch transmits power byvirtue of friction developed between contacting surfaces. The friction surfaceis typically flat and perpendicular to the axis of revolution. Two surfaces are pressed together by usingcompression spring. The friction force is used to bring the driven shaft to thecorrect speed gradually without excessive slipping.
Advantages of the friction clutch: – Smoothengagement and minimum shock during the engagement. – Frictionclutch can be engaged by disengaged when the machine is running since they haveno jaw.- Easyto operate.- Frictionclutch can act as a safety device.
As the torque exceeds it slips which is thesafe value, thus protects the machine. What is a plate clutch: Plate clutch consistof two overhangs, one of them is firmly keyed to the driving shaft, and theother is free to slide along the driven shaft due to the splined connection. Acompression spring is used to press these overhangs (flanges) against andtorque is transmitted by friction. A suitable mechanism is provided to compressthe clutch spring to disengage the clutch. What is a brake: A brake is amechanical device that enables motion by absorbing energy from a moving system.It is used for slowing or stopping a moving vehicle, wheel. Or to preventmotion, used by friction.
Most brakes mostly use friction between two surfacescompressed together to convert the kinetic energy of the moving object intoheat, using the methods of energy conversion. For example regenerative braking converts the energy to electricalenergy. There are other methods to convert kinetic energy into potential energyin the form of pressurized air. What are pumping brakes: pumping breaks areusually used where a pump is part of the machinery. For example an internal-combustion piston motor can stop the fuel supply, then internal pumping of theengine creates friction (breaking). Some engines use a compressed engine braketo gradually increase pumping desperation. Pumping breaks can usually useenergy as heat, or it be can regenerative brakes that recharge the pressurereservoir called a hydraulic accumulator. What are electromagnetic brakes: electromagneticbrakes are often used where an electric motor is part of the machinery.
Forexample, various petrol/electric cars usually use an electric motor as agenerator to charge the electric batteries and also regenerate the brake.Variant amount of diesel/electric trains use the electric motors to generateelectricity which is then sent to a bank which is then used as heat. What are disc brakes: a disc brake is a type of brake which uses clappersand pads against a disc to produce friction. This motion retards the rotationof a shaft, either to reduce its speed or to hold the vehicle motionless. Theenergy of motion is converted into heat which is then dispersed. What are drum brakes: A drum break is abreak which inhabits friction caused by a set of pads which press against arotating cylinder. The term drum break normally uses a break in which the padsare pressed on the inner surface of the drum.
What are couplings: A coupling is adevice which is used to connect two shafts together at their ends for the mainpurpose of transmitting power. Couplings do not normally do not disconnectduring the shafts operation, however there are torque restricting couplingswhich can slip or disconnect when some force is limit is exceeded.What is a sleeve coupling: A sleeve couplingconsists of a pipe where bore is fixed to the right tolerance based on theshafts geometric structure. If the coupling is used a lot a key way (a key is amachine element used to convert a rotating machine element to a shaft) is madein the bore in order to transmit the torque through the key.
Two threaded holesare provided in order to lock the coupling in position. sleeve coupling arealso known as box coupling in this coupling the shafts at the ends are coupledtogether and touching against each other which are covered by a muff orsleeve. What is clamp coupling: This coupling is made of two halves partsof the cast iron and they are joined together by the means of mild steel studsor bolts.
The advantages of this coupling is that the assembling of thecoupling is possible without change the position of the shaft. This coupling isused for transmission at different speeds. Task2: compare and contrast the operation and use of flat plate clutches,centrifugal clutches and fluid couplings in mechanical powertransmissions.
Flatplate clutch: are widely used in cars. The plate are mainly used butmulti plate clutches are also most commonly used in motorbikes. The plate islined with a friction of a material which has a splined hole in its centre.This will engage with the splines on the output shaft which will produce thedrive Whatare centrifugal clutches: A centrifugal clutch is used in vehiclesand in other applications where the speed of the engine defines the conditionof the clutch. For example in a chainsaw the clutch system uses centrifugalforce to automatically engage the clutch when the engine rpm rises above thelimit and to automatically disengage the clutch when the engine rpm deprecates. Wetvs dry systems: A wet clutch is immersed in a cooling lubricatingfluid which also keeps the surfaces clean and provides smoother performance andlonger life. Wet clutches, however lose energy to the liquid, since thesurfaces of a wet clutch can be slippery. Clutch discs can allow for the lowercoefficient of friction which eliminates slippage under power when fullyapplied.
A dry clutch is not dipped in liquid and uses friction to engage. Whatare cone clutches: a cone clutch has conical friction surfaces. Thecones thickness means that an amount of movement of the actuator (makes thesurfaces depreciate in speed than a disc clutch.
For example a cone clutchexample is a synchronizer ring in a manual transmission. The synchronizer ringcontrols the speeds of the shifts and the gear to ensure a smooth gearselection. Frictionclutches: some clutches are designed for not to slip. Torque mayonly be transmitted either fully engaged or disengaged to avoid detrimentaldamage.
An example if this is a dog clutch (is a type of clutch that couplestwo rotating shafts or other rotating components,) mostly used innon-synchromesh transmissions. Whatare fluid couplings: A fluid coupling is a hydrodynamic device usedto transmit rotating mechanical power. It is used in auto transitions as analternative to a mechanical clutch. As a fluid coupling operates kinetically,low viscosity fluids are used generally oils or transmission fluids are used.Increasing the density of the fluid increases the amount of torque that can betransmitted at a given input speed. However, hydraulic fluids like other oilsare subjected to change in viscosity with temperature change. This leads tochange in transmission performance. So when the performance has to be kept to aminimum, oil or transmission fluid, with high viscosity should be applied.
Whatis a transmission: A transmission is a machine in a powertransmission system, which provide controlled application of power. This isreferred to as the gearbox and drivetrain which uses the gears and gear trainsto provide speed and torque from rotating power source to a device. There aretwo types of transmission manual and automatic. A manual transmission is a typeof transmission used in motor vehicle applications. It uses a driver operatedclutch engaged and disengaged foot pedal, for regulating torque transfer fromthe engine to the transmission and a gear selector. An automatic transmissionis a type of transmission that can automatically change gear ratios as thevehicle moves. It allows an internal combustion engine, best designed to run ata high rotational speed.
Whatare mechanical power systems: usually refers to products used insystems with motion parts as opposed to systems powered electrically. Theseproducts included shaft couplings, chains and sprockets, belts and drivecomponents.