Posted in Automobile Technology

Major Components of Front Axle

The front axles are designed for two purposes, one to transmit the weight of the vehicle from springs to the front wheels and the other to permit the front wheels to turn right or left as required. The front axle assembly is a complete major component of a vehicle, which includes the axle beam, stub axles with brake assemblies, swivel pins and track rod. Axle Beam It is usually made of steel forging usually of “I” or “H” section. It is heat treated for extreme toughness and is machined to close limits. It serves the dual purpose of transmitting the weight of the vehicle from the springs…

Posted in Automobile Technology

Various Types of Chassis Frames

A well-designed chassis frame along with the suspension system, steering and brake system prevent most of the accidents of the fast moving vehicles. The power unit of an automobile connected with the transmission system is generally mounted on a structural frame, which is fitted to the axles either directly or indirectly through the media of suspension system. On this frame, the body and the cabin are fastened by bolts and nuts or by welding. However the term chassis therefore, includes the power unit, transmission system, and suspension system, steering and brake systems so as to enable a vehicle to move on the road safely during the day or…

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Final Drive Purpose

For turning the power flow at right angle from propeller shaft to the rear axle as well to provide mechanical advantage or leverage from the propeller shaft Final dive consists of a pair of helical or spiral bevel gear, i.e. a pinion connected to the propeller shaft and a ring gear connected to a flange on the differential case. It is designed to provide a reduction ratio of 4:1 and 5:1 I.e. when top or direct drive gear is engaged in the gearbox, rear wheels are driven at 1/4 to 1/5 of the engine speed. When an axle transmits power to the road wheels it…

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Rear Axle Casing and Classification

A rear axle is a complete component and comprises a casing, which carries the bevel pinion and shaft, crown wheel and differential gear assembly and the axle shafts. The axle also includes the road wheel hubs and brake assemblies. Axle casings are made of steel castings (machined where necessary) provided with inspection covers, oil level plugs or dipsticks and are made oil tight with oil retaining washers. Differential gear assemblies are mounted in a casing in a different ways with means of adjustment between crown and driving pinion. They can be removed from the casing but adjustment between crown wheels and driving pinion depends on the casing construction. The…

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Various Types of Universal Joints

A gearbox is rigidly mounted in relation to the engine and chassis, but when coupled to a rear axle by a propeller shaft, allowance has to be made for the variation due to the action of the road springs in the position of the rear axle relative to the chassis. Universal joints are, therefore, fitted for connecting two shafts inclined to one another at a small angle and at the same time to permit the transmission in the rotary motion from the engine to the road wheels throughout the variations in position of the rear axle relative to the gearbox and chassis. These joints are also used…

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Various Types of Propeller Shafts, Removal & Refitting Procedure

The propeller shaft, sometimes known as Cardon shaft or drive shaft is the medium by which the power from the engine driven gearbox is transmitted to the driving axles. It is made of steel and whether fitted in a front or rear wheel drive or between the main gearbox and an auxiliary gearbox, conforms to a similar pattern in which, one or two universal joints are incorporated. There are two types known as the open type and the enclosed type. Hotch-Kiss Drive Whenever driving or braking efforts are applied through the rear live axle of a vehicle, the axle structure as a whole tends to turn over or…

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Transfer Gearbox Construction and Purpose

What is Transfer Gearbox? Transfer Gearbox is used for choosing between rear-wheel-drive and four-wheel-drive, as well as you can chose between a street and a off road transmission.  Made with helical gears, an aluminium die cast gearbox and with a thoughtful shift linkage. Construction of Transfer Gearbox On vehicles where four wheel drive is employed; i.e. where the driving power can be applied to the front axle as well as the rear, it is necessary to transfer the drive from the main gear box to another gearbox known as the transfer gearbox. Three propeller shafts are fitted, one from the main to the…

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Auxiliary Gearbox Purpose, Construction and Operation

What is Auxiliary Gearbox? Auxiliary Gear Box is a mechanism that makes possible an increase in the tractive force of a motor operated vehicle by increasing the gear movement ratio of the transmission. For example, an auxiliary gearbox is used in the transmission mechanism of heave-duty motor vehicles such as tractors to increase mobility under heavy road conditions. Purpose of Auxiliary Gearbox On some vehicles an auxiliary gearbox is fitted immediately behind the main gearbox. Its purpose is to lower the whole range of gear ratios under more difficult road and load conditions. It is operated by a separate gear lever having three…

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Gear Change and Selector Mechanism

The movement along the main shaft of the sliding gears, driving dogs or Synchromesh unit is affected by the gear change mechanism and gear selector mechanism. The former is operated manually by the driver; the selector mechanism is incorporated in the gearbox itself and in response to movement of the gear lever, the required gear or driving dog is selected and moved into its correct position on the main shaft. Gear change Mechanisms In its simplest form the gear change mechanism consists of a gear lever, the lower end of which engages directly with the mechanism. A ball formed on the bottom of gear lever, is…

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Various Types of Gears and Gearbox & Construction of Gearbox

The wheels that engage each other in which turning of one turns the other is called gearing. A wheel having teeth made especially to engage similar teeth or other wheels is known as a Gear. If the two gears in a gear set are considerably different size the smaller one is called the pinion. The size of the teeth on any gear is determined by the pitch of the gear. The purpose of gearing are to provide a means for mechanical advantage in transmitting power which is in the form of torque or to change the direction of torque. Know about the purpose of gear box? Gear A…