14.67a and b Crosswinds sweeping tangentially underneath the tractor and trailer chassis and between and around the road wheels and axles produce a rise in the drag coefficient.. To part
Trang 1Centre line and offset double gap seal (vortex
stabilizer) (Fig 14.65(a and b)) A central vertical
partition or alternatively a pair of offset flexible
vertical plates attached to the trailer body (see Fig
14.65(a and b)) is effective in not only preventing
crosswinds passing through the cab to trailer gap
but also stabilizes the air flow entering the gap by
generating a relatively stable vortex on either side
of the plate or plates The vortex stabilizer is
slightly less effective than the extended side panel
method in reducing the drag coefficient when side
winds prevail
Rolled edge windcheater (Fig 14.66(a±d)) This
device consists of an extended quadrant section
moulding attached to the roof and both sides of the
leading edges of the forebody trailer panel When
there are sharp leading edges around the trailer
body air flowing through the cab to trailer space
tends to overshoot and hence initially separate
from the side panels of the trailer body (see Fig
14.66(a)) and even with rounded edging there is still
some overshoot and flow separation (Fig 14.66(b))
The effectiveness of different sectioned forebody
edge fairings are compared corresponding to a yaw
angle (relative wide angle) variation from 0 to 20,
see Fig 14.66(d) Here it can be seen that there is
very little difference between the semi circular and
elongated semi circular moulding but there is a
moderate improvement in the drag coefficient at
low yaw angles from 0 to 10 for the quadrant section; however, with the extended-quadrant moulding there is a considerable improvement as the yaw angle is increased from 0 to 20 With the extended quadrant moulding (see Fig 14.66(c)) the air flow tends to move tangentially between the cab
to trailer air gap; some of the air then scrubs along the flat frontage of the trailer body until it reaches the extended-quadrant step, is then deflected slightly rearwards and then again forwards before closely following the contour of the curved corner This makes it possible for the air flow to remain attached to the side panel surface of the trailer body, therefore keeping the drag resistance on the sheltered trailer panel side to the minimum 14.8.8 Tractor and trailer skirting
(Fig 14.67(a and b)) Crosswinds sweeping tangentially underneath the tractor and trailer chassis and between and around the road wheels and axles produce a rise in the drag coefficient To partially counteract the increase in vehicle drag with increased yaw angle, side skirts can be attached either to the trailer or the tractor or both units The effectiveness of both tractor and trailer skirting for one particular com-mercial vehicle is shown in Fig 14.67(a and b); here
it can be seen that with increased yaw angle (rela-tive wind angle) the effec(rela-tiveness of the trailer skirt peaked at a drag coefficient of 0.07 for a yaw
(a)
Tractor skirt
Trailer skirt
(b) 0.10
0.08
0.06
0.04
0.02
0
Yaw angle ( ) deg ψ
Tractor skirt
Trailer skirt
Fig 14.67 (a and b) Effectiveness of tractor and trailer skirting upon drag coefficient
Trang 2Crosswind
(c) Low cab + deflector + gap seal (d) Low cab + deflector + gap seal + trailer skirt
(e) Comparison of the effectiveness of various drag reducing devices
(e)
W
u
to
t def
lect or
En l
cos side
defle
ctor
Dfle cto + e
r ga
p sea l
Defle cto
g
r +
+ s
skirt
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
Yaw angle ( ) deg ψ Fig 14.68 (a±e) Influence of various devices used to reduce drag when vehicle is subjected to crosswinds
Trang 3angle of 5 The skirt effectiveness in reducing the
drag coefficient then decreases steadily over an
increasing yaw angle until it reaches its minimum
of 0.04 at a yaw angle of 20 Conversely the trailer
skirt's effectiveness with respect to the yaw angle
rose rapidly to 0.06 over a yaw angle range of 5;
the drag coefficient then continued to rise at a
slower rate so that for a yaw angle of 20the drag
coefficient effectiveness reached a maximum of just
over 0.09 However when considering attaching
skirts to a vehicle there can be a problem with the
accessibility for routine inspection and for
mainten-ance of the steering, suspension, transmission and
brakes; they can also restrict the cooling of the
brake drums/discs
14.8.9 Comparison of various devices used to
reduce vehicle drag (Fig 14.68(a±e))
A comparison of various devices used to reduce
vehicle drag particularly when there are crosswinds
can be seen in Fig 14.68(a±e) The graph shows for a
low cab and no roof deflector that the drag is at its
highest due to the cab to trailer step and that the drag
coefficient rises with increasing crosswind yaw angle (relative wide angle) from 0.48 to about 1.05 over a
15 increase in yaw angle (see Fig 14.68(a and e));
a reduction in the drag coefficient occurs when a cab roof deflector is matched to the trailer body (Fig 13.68(b and e)) When a cab to trailer gap seal is attached to the trailer there is a further reduction in the drag coefficient particularly with increasing yaw angles (Fig 14.68(c and e)), and finally there is even
a greater drag coefficient reduction obtained when fitting a trailer skirt (Fig 14.68(d and e))
14.8.10 Effects of trailer load position on
a vehicle's drag resistance (Fig 14.69(a and b)) The effects of positioning a container load on a platform container truck considerably influences the drag resistance This becomes more noticeable with crosswinds (see Fig 14.69(a and b)), and that with a yaw angle of 20the drag coefficient without
a container was only 0.7 whereas with the container mounted in front, centre and towards the rear, the drag coefficients reached 1.2, 1.6 and 1.7 respectively
Front
Centre position
Rear
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
Yaw angle ( ) deg ψ
(b)
Rea
r pos ition
Cen trepo sition
No co n
(a)
Fig 14.69 (a and b) Effects of trailer load position upon drag coefficient
Trang 4Absorbed impact dissipation 11
Absorption of vibration 10
ABS/TCS system 268, 269
Acceleration pedal sensor 441, 446
Acceleration sensor (suspension) 440, 446
Accelerator switch 551
Accumulator 444, 446
Ackermann principle 347
Acoustic materials 10
Active hydro/coil spring suspension 442
Active safety 11
Active suspension 439
Actuator chamber 543, 544
Adhesion factor 451
Adjustable deflector 623, 626, 627
After body drag 611
Aerodynamics 584 see vehicle body aerodynamics
Aerodynamic drag 584, 590
Aerodynamic lift 598
Aerodynamic lift control 606
Aerodynamics for different cab to trailer body
heights 619, 620
Aerofoil 596, 601
Aerofoil drag 599
Aerofoil lift 599
Aerofoil profile 599
Aerofoil spoiler 610, 612
After flow wake 593
Alignment checks; body and chassis 11
Alternating voltage frequency 492
Angle of attack 599, 602
Angle of contact 198
Angle of inclination 599
Angle spring clutch (Spicer) 49, 50
Angular
Deflection 40, 41
Ratio (steering) 31
Anti-dive suspension control 402, 403
Antilocking brake system
Air/electric (commercial vehicles) 492
Hydro/electric 490
Hydro/mechanical 488
Antioxidants and ozonates 279
Anti-roll bars 385
Anti-squat suspension control 402, 403
A-frame drawbar 26, 30
Air density 592
Airdomic automatic chassis lubrication system 32±36
Air (pneumatic) operated power brakes
Air over hydraulic brake system 510, 511
Introduction to air power brakes 510 Parking circuit 512
Secondary line circuit 510±514 Secondary/park line circuit 514, 515 Service line circuit 510±514
Towing truck or tractor spring brake two line system 514, 515
Towing truck or tractor spring brake three line system 513, 515
Trailer three line brake system 512, 513 Trailer two line braking system 515 Tractor three line brake system 511, 512 Air operated power brake equipment Absorption 517
Air dryer 516±518 Automatic reservoir drain valve 541, 542 Brake actuator chambers 543
Compressed air supply 510±514 Compressor mounted unloaded with separate governor 520, 521
Compressor reciprocating 518 Compressor with clutch disengagement
518, 519 Desiccant cartridge 516, 517 Differential protection valve 534±536 Foot (treadle) control valve (dual concentric)
527, 528 Diaphragm/piston chamber type actuator
544, 545 Double check valve 536, 537 Double diaphragm chamber type actuator
543, 544 Foot (treadle) control valve (dual delta)
528, 529 Hand control valve 529, 530 relative Humidity 517 Multi-relay (Triple) valve 515, 539, 540 Non-return (check) valve 526
Pressure reducing valve (piston type)
525, 526 Pull type piston/diaphragm chamber
544, 545 Purge chamber 516, 517 Push type piston/diaphragm chamber
544, 545 Quick release valve 533 Relay emergency valve 534, 535 Relay valve (piston type) 532 Safety valve 526
Single and multi-circuit protection valve 524, 524
Trang 5Air operated power brake equipment (continued)
Single diaphragm chamber type actuator 543, 54
Spring brake actuator 545, 546, 547
Spring brake hand control valve 530, 531
Supply dump valve 515, 539±541
Triple diaphragm chamber type actuator
543, 544
Variable load valve 537, 538
Unloaded valve (diaphragm type) 522
Unloaded valve (piston type) 523
Air resistance 60, 592
Air resistance opposing motion 592, 593
Air spring bags
Bounce frequency 435
Laden to unladen weight ratio 435
Ride characteristics 435
Ride frequency 435
Involute bellow spring 434
Rolling diaphragm spring 434
Air suspension for large cars and commercial vehicles
Air spring bags 434
Air spring characteristics 435, 436
Anti-roll rubber blocks 435
Compressor operation 431, 448, 449
Compressor pressure switch 447
Driver's function switches 448, 449
Electronic controlled system 447±448
Electronic control unit 447, 448
Engine speed sensor 447
Exhaust solenoid valve unit 448, 449
Hand brake switch 447
Height sensors 447
Inlet and outlet solenoid valve 448, 449
Isolating valve 433, 434
Levelling valve 432, 433
Ride height solenoid valve 447, 448
Unloaded valve 448, 449
Vehicle speed sensor 447
Air spring (pneumatic suspension) 447, 448
Air streamlines 586, 587
Air swirl 595, 596
Angle spring clutch (Spicer) 49, 50
Angular
Deflection 40, 41
driven plate cushioning and torsional damping 38
Ratio 311
Anti-dive active control suspension 443
Antilocking brake system (ABS) 486±494
Air/electric antilock braking system for commercial
Vehicles (WABCO) 492±494
Antilock brake system characteristics
492, 494
Electronic control unit 490
Fundamentals 486±489
Hydraulic-electric antilock system for cars
(Bosch) 490±492
Hydro/electric modulator 490
Hydro-mechanical antilock brake system (SCS Lucas
Girling) 488±490
Solenoid control valve unit 493 Speed sensor and excitor 490 Anti-squat active control suspension 444 A-post 2, 3
Apportioned braking 482 Aquaplaning (hydroplaning) 287 Arch pan 2
Arcurate horseshoe spring 39 Articulation 26
Asbestos based lining 41 Asbestos substitute friction material 41 Aspect ratio (tyre profile) 288
Attached transverse vortices 597 Automatic
Clutch adjuster 57 Drawbar coupling 30 Lubrication 34 Reservoir drain valve 451 Shoe adjustment 462 Slack adjuster 469 Automatic chassis lubrication system 32, 34, 35 Automatic drawbar coulping 30, 31
Automatic transmission Annular carrier 117±122, 134±136, 151, 153, 155±157 Annular gears (ring gear) 117±153, 155±157 considerations 117
clutches/brakes 172, 175, 176 converter lock-up clutch valve CLCV 172, 175, 176 converter pressure control valve CPCV 172, 175, 176 converter pressure valve CPV 172, 175, 176 electronic pressure regulating valve
current-pressure characteristics 171 five speed and reverse transmission 155 four speed and reverse longitudinal mounted transmission 117
Hydraulic control sytem 123 Lock-up control valve 134 lubrication pressure valve LPV 172, 175, 176 One-way clutch 119±121, 135, 136, 156, 157 Retaining valves RV-E, RV-G 172, 175, 176 Planet carrier 117±122, 134±136, 151, 153, 155±157 Planet gears 117±122, 134±136, 151, 153, 155±157 Planetary gears 119, 120, 135, 156, 157 Pump-internal gear crescent type 171, 175 selector position valve SPV 171, 175 Sun gears 117±122, 134±136, 151, 153, 155±157
Three speed and reverse transaxle mounted transmission 134
traction/coasting valve T/C-V 172, 175, 176 traction valves TV(4±5), TV(5±4) 172,
175, 176 upshift clutch overlap control characteristics 163 shift valves SV 124, 125, 127, 128±132,
140, 11, 171 signal sensors 166, 167 Auxiliary splitter and range gearbox 78, 79 Axial clutch driven plate
Arcuate segment 38
Trang 6Borglite segments 38
Crimped spring steel segment 38
Cushioning 38
Torsional damping 39±41
Axis of oscillation 13, 14
Axle and chassis leaf spring attachment
416, 417
Axle attachment 389
Backlash clearance/allowance 230
Back sloping front body 618, 619
Balancing machine for wheels and tyres 305±309
Bald tyre grip 71
Ball and socket towing bar coupling 30, 32
Ball
Cage 219
Joint 337
Rolling constant bearing friction 193
Track convergence 219
Ball and roller
internal clearance 196, 197
Effects of diametric clearance and axial load on angle
of contact 197, 198
Band
Brake (automatic transmission) 124, 125, 126
Servo 144
Base area 594
Base drag 594, 595
BCpost 2, 3
Beads; tyres 23
Beam cross-member sub frame 9
Bearings
ball and roller load distribution 202
coefficient of friction 202
Fatigue 202
Friction 201
Hardness 201
Internal clearance 196
Life expectancy 211
Load 196
Noise 234
Materials 201
Preload 209
Rigidity 208
Selection 209
Bell housing 45
Bell housing runout 46
Bellows; friction retarder 552
Bendix tracta joint 223
Baulking ring 66
Belleville spring washer 51
Belt design (stepless speed transmission) 150
Bending stress and resistance 6, 7, 8
Bendix joints 220
Bevel gear
Double reduction outboard axle 243
Central differential 260
Defective differential 234
Separation force 238
Bevel pinion Bearing preload 226, 227 Depth setting 226 Birfield joint 215 Blades (impellor or turbine) 98 Bobbin mounts 24
Bobtailed 594, 595 Boot (trunk) 589 Bonnet (hood) 589, 590 Boot pan 2
Boundary layer 584, 585 Bulkhead 2, 4
Body and chassis alignment checks 11, 12 Body direct weight transfer couple 382 Body roll
Active control suspension 443 Angle 383
Coupling 381 Couple distribution 383 Lateral (side) force distribution 383 Overturning coupling 382
Body roll Stability analysis 381 Stiffness 382 Weight transfer 282, 383 Body subframe 6, 9 Body shell vibration 10 Boom (noise) 10 Boot height air drag 615±617 Boot pan 2, 4
Bonnet slope 601, 604 Borglite segment spring 38, 39 Bounce mode 408
Bottom gear ratio 94 Box section 8 Bracing Belt 281 Stays 33 Brake pedal/pressure sensor 441 Brakes
Adhesive factor 451, 452 coefficient of friction 450 Efficiency 450, 451 Fundamentals 450 Kinetic energy 450 Stopping distances and efficiency 450, 451 Brake actuator chambers 543
Brakes Ð air (pneumatic) power operated 511±546, also see air operated power brakes
511±546 Brakes Ð commercial disc brakes
504, see disc brakes pneumatically operated Brake distribution
Inertia and progressive pressure limiting valve 486
Inertia pressure limiting valve 485, 486 Load sensing pressure limiting valve 483, 484 Pressure cut-off 483, 384
Pressure limiting valve 482
Trang 7Brakes Ð electronic/pneumatic brakes (EPB)
ABS solenoid control valve 559, 561, 562
Air dryer 559
Axle modulator for rear axle brakes 559,
564, 565
Brake switch 562, 563
Brake value sensor (BVS) 559, 560, 561
Compressor 559
Coupling head for brake and supply 559,
566, 567
Electronic control module for brakes
558, 560
EPB trailer control valve 559, 566, 569
Four circuit protection valve 559
Parking hand control valve 566, 567, 569
Pressure limiting valve 561, 562
Proportional relay valve 559, 560, 562, 569
Redundancy brake circuit 558, 559, 568
Redundancy vale 559, 564, 565
Reservoir tank 559
Single circuit diaphragm actuator 559, 562, 563
Speed sensor (nS) 559
Spring brake actuator 559, 564, 565
Throttle valve 566, 567, 569
Trailer control valve 566, 59
Trailer relay emergency valve 569
Travel sensor (TS) 559
Two way valve (2WV) 564, 565, 568
Unloaded valve 559
2/2 solenoid valve 564, 565, 564, 568
3/2-way valve for auxiliary brake effect 559,
561, 562
Brake friction lining and pad properties
DuPont's Kevlar 460
Friction materials 460
Recovery from fade 459
Resistance to heat fade 458
Resistance to moisture sensitivity 460
Resistance to rubbing speed 459
Resistance to the intensity of pressure 459
Resistance to wear 459
Resistance to water contamination 460
Brake master cylinders
Compensating port tandem type 478±480
Mecanindus (Roll) pin tandem type 480±482
Pressure differential warning actuator
480±482
Primary and secondary recuperation poppet
valves 481
Brake servos (booster)
Direct acting suspended vacuum assisted brake
servo 496±498
Hydraulic servo assisted brake system
(ATE) 499±504
Hydraulic servo unit 501, 503
Operating principle of a vacuum servo
494±496
Pressure accumulator with flow regulator
and cut-out valve unit 501, 502
Rear brake circuit pressure regulator and cut-out device 503±505
Vacuum pumps 498, 499 Vacuum servo operating characteristics
495, 498 Brake shoe and drum fundamentals Back plate (torque plate) 452 Drag (friction force) 452 Drum shoe arrangements 453 Duo-servo shoe 455
Leading and trailing shoes 453 Leading shoe 452
Retarding wheel and brake drum torques 453 Servo action
Shoe and brake factors 453 Shoe self energization 45 Two leading shoe 455 Two trailing shoe 455 Brake shoe expanders and adjusters Automatic adjuster 462 Brake application with new, half and fully worn linings 463
Hand brake operation 461
`S' cam shoe expander Cam and shoe working conditions 465 Cam design conditions 465
Cam profile geometry 465 Cam expander requirements 465 Self-adjusting quadrant and pinion brake shoe mechanism 462
Self-adjusting sector and pawl shoe mechanism 461 Strut and cam brake shoe expander 461
Tappet strut and plunger 464 Wedge shoe adjuster unit 464 Wedge type shoe expander with automatic adjuster 467, 468, 569
Manual slack adjuster Automatic 469, 471 manual 467, 470 Brake disc and pad fundamentals Automatic handbrake adjuster 476 Braking torque 455
Caliper 455, 456 Comparison of shoe and pad factors and shoe stability 457, 458
Centre of pressure 455, 456 Cooling disc and pads 47 Pad alignment 456 Principle of the disc brake 455 Ventilated disc 456
BSI designated bearing clearance fits 197, 198 Bulkhead 5
Bump and pitch mode 407 Bump stops 387, 388, 434 Bump stop characteristics 388, 389 Cab Ð high and low 626, 627 Cab roof deflector 622, 626 Cab to body gap 623, 624
Trang 8Cab to trailer body gap 628
Cab trailer body gap seals 629, 630
Cab to trailer body roof height step 619, 620, 622
Cab extended side panels 629, 630
Cabriolet car 616, 617
Camber
Angle 368
Scrub 294
Steer 294
Thrust 393
Cam-ring 331
Carbon black 279
Cantrail 2, 3
Caravan drawbar coupling 32
Carl Weiss joint 220
Carrier pin 88
Castor angle 370
Centre line gap seal 630
Centre of gravity 14, 15
Centre of pressure 292
Centre point steering 370
Centrifugal force 98, 301
Cerametallic friction material 42
Chassis 4, 6
Chassis misalignment 12
Citroen hydro-pneumatic suspension 408
Clutch air/hydraulic servo 56, 58
Clutch brake 48, 51
Clutch cable linkage with automatic adjuster 54, 57
Clutch with composite flywheel and integral single
plate diaphragm 57, 59
Clutch drive and driven member inspection 43
Clutch drive lugs 50
Clutch friction materials 41
Clutch internal self-adjustment 51
Clutch misalignment 44
Clutch Ð hydraulically operated for automatic
transmission 52
Clutch pedal with over-centre spring 54, 56
Clutch pressure plate 46
Clutch release lever adjustment 47
Clutch release thrust bearing 208
Clutch retraction springs 49, 50
Clutch self-adjustment 54
Clutch servo piston and chamber 53
Coast side of crownwheel tooth 233
Coefficient of friction 193
coefficient of Proportionality 593
Collision safety 10
Commercial vehicle aerodynamics 617
Commercial vehicle suspension axle beam
location 415
Compliance steer 399, 400
Compressor 518
Constant velocity joints
Birfield joint based on the Rzeppa
principle 215, 216
Constant velocity joints
ball cage 219
ball track convergence 218 fault diagnoses 219 joint construction 216 Mechanical efficiency 219 track groove profile 218 Carl Weiss constant velocity joint 220 constant velocity principle 220, 221, 222 joint construction and description 220, 221 Constant velocity joints 214
Double Hooke's type constant velocity joint 214, 1215
Hooke's joint cyclic speed variation due to drive
to driven shaft inclination 213 Hooke's universal joints 212 Pot type constant velocity joint 219, 220 The need for constant velocity joints 212 Tracta constant velocity joint 222, 223 Tripot universal joint 223, 224 Tripronged universal joint 224, 225 Carrier pin 88
Central (third) differential (heavy goods vehicles) 249
Chassis 6 chassis alignment check 11, 12 Clutch air/hydraulic servo 56±57 Clutch friction 37
Coefficient of friction 270 Compensation port type tandem master cylinder 478
Composite flywheel and integral clutch 57 Compound epicyclic overdrive 92 Condenser 570±573, 576
Cone angle 41 Cone clutch 41 Conformity ratio 218 Constant velocity joints 212 Contact centre 368
Contact patch 368 Continuously variable belt and pulley transmission 149±155
Continuously variable transmission epicyclic gear train 153
Continuously variable transmission performance characteristics 155
Converging mount geometry 15±17 Converging section (air flow) 585 Converging taper roller gearing axis 199, 200 Converter check valve 118, 128
Converter pressure valve 140 Cornering
Force (lateral force) 289 Power (cornering stiffness) 290 Properties of tyres 288 Corner vanes 628 Corrugated ribs 2 Crankshaft flywheel flange runout 44 Crankshaft end float 44
Cross members 4 Cross winds 624, 625, 629
Trang 9crownwheel and pinion axle adjustments
adjusting crownwheel and pinion backlash and
differential bearing preload 229
Adjusting pinion bearing preload 227
Removing differential assembly with shim
preloaded bearings 226
Setting crown wheel and pinion backlash and
preloading differential bearings using
adjusting nuts 231
Setting crown wheel and pinion backlash using
shims 229
Setting differential cage bearing preload using
shims 229
Setting pinion bearing preload using collapsible
spacer 228
Setting pinion depth 226
crownwheel and pinion tooth contact checks
Prepare crown wheel for examining tooth
contact marks 232
Understanding tooth contact marks 232
Ideal tooth contact 232
Heavy face (high) tooth contact 233
Heavy flank (low) tooth contact 233
Heavy toe contact 233
Heavy heel contact 233
Coupling jaws 27, 28
Coupling efficiency 102
Coupling jaws 26
Coupling phase 108, 109, 114
Coupling point (fluid drive) 108
Crack point 498
Crankshaft
End float check 44
torsional vibration 39, 40
crawler or deep gears 78
Creep effects 271
Crimp spring clutch 38
Critical slope angle 613, 614
Critical speed 40, 106
Cross-ply tyres 274, 281
Crushproof cell 11
Crumble zone 11
Cyclic pitch noise 234
Dash panel 3, 4
Dash-pot 90±92
Damping of vibrations 10, 18
Dead axle (non-drive) 392
Decoupling 14, 17
DeDion axle rear wheel drive suspension 398
Defective differential gears 234
Deflector plate angle 624, 626
Detachable double row angular contact ball or
taper roller bearings 404
Design point (fluid drive) 108
Diaphragm chamber actuators 543, 544
Diaphragm clutch Ð pull type 46
Diaphragm clutch Ð multi plate type 46
Diaphragm spring 46
Diagonal front to rear brake split 477 Diagonally integral hydraulic damping 24, 26 Diametic clearance 197
Differential air pressure switch 583 Differential
Cage bearing preload 229 Cornering action 239 Lock 235
Torque distribution 240 With viscous coupling 241 Protection valve 534 Differential locks Differential lock mechanism 234, 235 Differential lock with air control 236 Directional stability 296
Disc brake pad support arrangements Combined foot and hand brake caliper with automatic screw adjustment (Bendix)
476, 477 Sliding pin type caliper 473, 474 Sliding yoke type caliper 472, 473 Swing yoke type caliper 472, 477 Twin floating piston caliper with hand brake mechanism 474, 475
Disc brakes air (pneumatically) operated Automatic pad clearance chain-driven type adjuster 509
Automatic pad clearance gear-driven type adjuster 507, 509
Floating caliper with eccentric shaft and lever 504±507
Floating caliper with integral half eccentric lever arm 504±506
Override clutch for automatic pad clearance adjustment 507±509
Dish wheel centre point steering 370 Distorted differential housing 234 Disturbing force 18
Diverging section (air flow) 586 Dog clutch teeth 66
Double check valve 536 Double diaphragm chamber 543 Double hook's joint 214 Double inclined wedge with longitudinal control mounting 22
Double reduction axles The need for double reduction final drives 242
Double reduction axles with first stage reduction before the crown wheel and pinion 242, 243 Double reduction with bevel gears ahead of spur gears 242, 243
Double reduction with bevel gears ahead of spur gears 243
Inboard and outboard double reduction axles 244 Inboard epicyclic double reduction final drive axle (Scammell) 244
Inboard epicyclic differential and double reduction axle (Kirkstall) 244, 245
Trang 10Outboard epicyclic bevel gear single and two seed
double reduction axle 246, 247
Outboard epicyclic spur gear double
reduction axle 245, 246
Double self-aligning bearing 205
Double shear/wedge mountings 19
double shear mountings 20
Double spherical roller bearing 205, 206
Double sun gear 119, 120
Double taper roller bearings 205, 206
Double yoke 215
Downshift 14
D-post 2, 3
Drag coefficient 593
Drag due to trailer load position 634
Drag reducing devices 629, 630, 631, 632
Drawbar trailer 30
Drier 573, 579
Drip-rail 2
Drive clutch 119±121
Driven plate inertia 37
Driven plate transmitted torque capacity 37
Driven plate wear 37
Drumming and droning (noise) 10
Dual `concentric' foot control valve 527
Dual `Delta' foot control valve 528
Dual front axle steer 346±349
Dual- or spilt-line braking systems
Diagonally front to rear brake split 477, 478
Front to rear brake line split 477, 478
Triangular front to rear brake split 478
Dual-rate helper springs 418, 419
Duo-servo shoe brakes 455
Drumming (noise) 2
Dummy pinion 226
Dunlop optical alignment equipment 339
Eaton two speed epicyclic gear train 249, 250
Eccentric and range 62
Economy speed range 62
Eddies 588, 589
Eddy current 553
Effective inclination angle 615, 616
Elastic hysteresis 193
Elastic stiffness, compression and shear 13
Electric motor 491
Electronic control unit 490, 491
Electric power assisted rack and pinion
steering 363±367
Electro-hydraulic limited-slip differential
Multiplate wet clutch mechanism 262, 263
Operating conditions 262, 263
Electromagnetic eddy current retarder
(Telma) 553
Electro-magnetic progressive regulating valves
EPRV1, EPRV2, EPRV3, EPRV4 166,
167, 168, 169, 171
Electro-magnetic (solenoid) valves (MV1, MV2,
MV3) 166, 167, 168, 169, 171
Electronically controlled pneumatic (air) suspension 447, 448
Electronic-pneumatic brakes (EPB) 558 Electronic transmission control unit (ETCU) 166, 167, 168, 169 Energizing ring 66
Engine braking via converter 109 Engine compressed air retarder (Jacobs) 548
Engine overrun retarder 547 Engine to body/chassis mountings 19 Engine speed sensor (pneumatic suspension)
447, 448 Engine transmission and body structure mounting 12
Engine vibration 12 Engine and transmission vibrations 15, 16 Engine speed ratio chart 77
Engine torque rise and speed operating range 61
Entrance vane guide 105 Epicyclic overdrive gearing 86 Epicyclic
Gear differential and double reduction axle 244 Gear train 117
Over drive 88 Two speed axle 249 Equalization of vehicle laden weight between axles 422
Etched pinion head 227 Evaporator 570±573, 576 Excitor ring 490
Exit fluid velocity 107 Expanders and adjusters 461 Expansion valve 571±573 Exposed wheel air flow pattern 606, 607, 609 Extended quadrant moulding 631, 632 Eye bolt (clutch) 47, 48
Eye and bolt draw bar 26, 30 Fade recovery 458, 459 Failure of service line pressure 540 Fastback drag 612, 614
Fatigue failure 234 Fault diagnosis; power assisted steering 335 Female cone 66
Fennille (Tracta constant velocity joint) 222 Fifth wheel
coupling 24 Coupling jaw 26, 28, 29 Guide ramp 27 Kingpin 26, 27 Pawl 28 Pivot pin 28, 29 Table plate 27 Trip pin 28 Trailer platefrom 27 Trunnion 29 Fifth wheel table 25, 27