Two And Three Wheeeler.pptx

UNIT III CHASSIS AND SUB-SYSTEMS Presented by A.MOHSIN AHMED AP/AUTO

Load on the frame

Construction of frame

Construction of frame

Construction of frame

Mounting provisions on frame • Engine and transmission mountings – 2 to 3 places or 6places • Controls, pegs and stands – • Rear suspensions • Tank fender and seats • Battery ,wiring and electrical equipments

Mounting provisions on frame

Back bone type frame

Double beam type frame

Trellis frame

Trellis frame-contd • Trellis frames are a favorite among European bike makers like KTM, Ducati. The only made in India bike with a Trellis frame currently is the KTM 200 Duke

Step – through frame

Engine based frame

Engine based frame -contd

Twin spar or perimeter frame

Twin spar or perimeter frame Perimeter Frame: Perimeter frames also known as Twin spar/beam frames. These frames are currently the favorite among MotoGP teams. Like the trellis frames, perimeter frames connect the steering head to the swing arm in the shortest distance while the engine is suspended from the frame. The engine can be said to be held around the “perimeter” of the frame.

Twin spar or perimeter frame • The only two bikes with perimeter frame currently in India are the Bajaj Pulsar 200NS and the Yamaha R15. No wonder why the R15 is so much appreciated for its handling and the Pulsar 200NS is getting rave reviews from auto publications for its handling prowess. Such frames are comparatively costly to manufacture though. Advantage: One of the best/sportiest/advanced frames that one can put on a bike Benefit: Race track bike like sharp and stable handling and braking

Twin spar or perimeter frame

Monocoque frame

Chassis of two wheeler • The two-wheeler chassis consists of the frame, suspension, wheels and brakes. • The chassis is what truly sets the overall style of the two-wheeler. • Automotive chassis is the main carriage systems of a vehicle. • The type determines the gearing configuration, flex and the type of modifications that can be accommodated

Frame • The frame serves as a skeleton upon which parts like gearbox and engine are mounted. • It can be made of steel, aluminum or an alloy. • It keeps the wheels in line to maintain the handling of the two-wheeler.

Suspension • It is a collection of springs and shock absorbers. It can be of two types: front suspension and rear suspension. • It insulates both the rider and the bulk of the machine from road shocks and also keeps the wheels in the closest possible contact with the ground and gives control of the vehicle to the rider. • The front suspension helps to guide the front wheel, to steer, to spring, to dampen, and to provide support under braking.

Wheels • A wheel is a circular object which with an axle, allows low friction in motion by rolling. • A wheel is made up of the rim and spokes or disc plate. • Wheels should be aligned properly because it directly influences driving. • Two-wheeler wheels are generally of aluminum or steel rims with spokes.

Brakes • Generally, there are two independent brakes on a twowheeler: one set on the front wheel and one on the rear, however, there are many models which have 'linked brakes' and apply both at the same time. • The front brake is generally much more powerful than the rear brake. • Brakes can either be drum or disc based. • When the rider operates one of the brakes, a fluid element known as hydraulics is pressurized to provide the required forces to squeeze the brake pad material onto the rotor and slow down or stop the vehicle.

GEAR BOX • A gear is a toothed wheel designed to transmit the force to another gear or toothed component. • The teeth of a gear is known as cogs. • They are shaped to minimize wear, vibration and noise and at the same time maximize the efficiency of power transmission. • Gears of different size, the larger one is called a wheel and the smaller one is called a pinion, are used in pairs so that the force of the driving gear can produce a larger force in the driven gear, that also at a lower speed or it can be or the purpose of producing a smaller force at a higher speed.

Single plate clutch

Single plate clutch-1 • It consists of – Pressure plate – Clutch plate – Springs – Release fingers • The single disc clutch is a plate type of clutch in which a single thick iron plate is coated with friction material on both sides. • There is only one clutch plate in this type. • The clutch plate is pressed against the flywheel of the engine by the spring loaded pressure plate. • The pressure produced by a number of springs, located between the pressure plate and the housing, which is bolted to the flywheel, holds the friction surfaces firmly in contact. • When the pedal of the clutch is depressed, the pressure plate is pushed back by the release fingers.

Single plate clutch-2 • This releases the pressure from the clutch plate and disengages the clutch. • Then the clutch plate stops rotating but the fly wheel continues to rotate. • When the clutch pedal is released, the pressure plate forces them to turn together as one unit. • Thus the power of the engine goes to the gear box for onward transmission to rear wheels. • This type of tractor clutch plate is usually foot operated.

MULTI PLATE CLUTCH • A multi-plate clutch has more than one driven plate. Although this type of clutch has been widely used on cars up to about 1930, the several advantages of the single-plate clutch, specifically its ability to completely disengage the drive has caused a very rare use of a multi-plate unit as a main transmission clutch installed between the engine and gear box. • However, a multi-plate type of clutch finds a use in automatic gearboxes. In these gearboxes, a number of clutches hold the various gear elements, and as the clutch diameter in these units is limited, a multi-plate clutch is suitable.

MULTI PLATE CLUTCH

• Figure illustrates the layout of a multi-plate spring type clutch, fitted on early motor cars. • A cover, bolted to the flywheel, engages by means of slots with a series of lugs on the outer plates. • These steel plates may be plain or fitted with cork or friction material inserts and act on inner plates, splined to a hub. • Thrust springs push the plates together to form a drive.

• For the clutch disengagement, the end plate is withdrawn to compress the springs and release the other plates. • In this arrangement it is difficult to ensure the disengagement of all plates. • To overcome this problem the plates are either dished or fitted with small springs to push the plates apart. • Generally wet type clutch is used in automatic gearboxes, and is operated by a piston governed by hydraulic pressure. Sintered bronze plates of partially fusing powdered bronze or compressed paper are used in many designs. • The porous surface of this plate traps the oil, to provide long life and smooth operation.

Multi-plate Diaphragm Type Clutch • These clutches basically have drive and driven plates. • The drive plates are not allowed to rotate independently by using interlocking lugs and slots, which do not permit relative rotational spin, but axial movement. • The driven plates are mounted on the internally splined hubs, which splines on the gearbox spigot shaft (Fig. 24.17). • A dished annular disc forms the diaphragm spring, the inner portion of which is radially slotted and the outer ends are enlarged with a circular hole to prevent stress concentration during disengagement. • These radial slots divide the disc into number of release levers. • A shouldered pivot post, riveted to the cover pressing locates the diaphragm spring in position. • These rivets also hold a pair of fulcrum rings on either side of the diaphragm.

• These clutches basically have drive and driven plates. The drive plates are not allowed to rotate independently by using interlocking lugs and slots, which do not permit relative rotational spin, but axial movement. • The driven plates are mounted on the internally splined hubs, which splines on the gearbox spigot shaft (Fig. 24.17). A dished annular disc forms the diaphragm spring, the inner portion of which is radially slotted and the outer ends are enlarged with a circular hole to prevent stress concentration during disengagement. • These radial slots divide the disc into number of release levers. A shouldered pivot post, riveted to the cover pressing locates the diaphragm spring in position. • These rivets also hold a pair of fulcrum rings on either side of the diaphragm.

Multi-plate Hydraulically Operated Automatic Transmission Clutches

Two wheeler gearboxes

Constant mesh gear box

Constant mesh gear box

Ball lock mechanism

Ball lock mechanism

Trunnion locking mechanism

Trunnion locking mechanism

Sequential gearbox

Sequential gearbox

Sequential gearbox

Gear shifting mechanism

Hand operated gear shifting

Foot operated gear shifting

CVT

ACTUAL ASSEMBLY OF CVT

FINAL DRIVE

SUSPENSION SYSTEM • Functions of Two Wheeler Shock Absorbers: • They absorb the shock from bumps on the road and helps to make riding safe and smooth. • they allow the use of soft springs while controlling the rate of suspension movement in response to bumps. • They also, along with hysteresis in the tire itself, damp the motion of the unsprung weight up and down on the springiness of the tire. • Shock Absorber system make the vehicle manageable

FRONT SUSPENSION SYSTEM • Front suspension is often implemented with a set of shock absorbers in the front fork. The suspension travel and handling characteristics vary depending on the type of mountain biking the fork is designed for. For instance, manufacturers produce different forks for cross-country (XC), downhill (DH), and freeride riding. • Suspension fork design has advanced in recent years with suspension forks becoming increasingly sophisticated. The amount of travel available has typically increased. When suspension forks were introduced 80-100 mm of travel was deemed sufficient for a downhill mountain bike. Typically this amount of travel is now more normal for cross country disciplines. Downhill forks can now offer in the region of 170 to 203 mm of travel for handling the most extreme terrain. • Other advances in design include adjustable travel allowing riders to adapt the forks travel to the specific terrain profile. eg less travel for uphill sections more travel for downhill sections. Advanced designs also often feature the ability to lockout the fork to completely eliminate or drastically reduce the fork's travel for more efficient riding over smooth sections of terrain. This lockout can sometime be activated remotely by a cable and lever on the handlebars.

SHOCK ABSORBER

The shock absorber usually consists of two parts: a spring and a damper or dashpot.

REAR SUSPENSION SYSTEM

Freewheel drives

Free wheel mechanics

Benefits

Applications

Panel Meters Control on Handle Bar