汽車專業(yè)英語2-Unit 4

1、Unit 4Unit 4 Steering System Steering Systemn1. Description1. DescriptionnThe steering system is the means by which the The steering system is the means by which the driver of a vehicle is able to control the driver of a vehicle is able to control the position of the front wheels. The system must po

2、sition of the front wheels. The system must provide ease of handling, good directional provide ease of handling, good directional control, and stability. This is achieved by the control, and stability. This is achieved by the steering system in conjunction with the steering system in conjunction wit

3、h the suspension system.suspension system.n(1)(1) Manual steering Manual steeringn Steering linkage Steering linkagenThe steering The steering linkagelinkage includes the steering arms includes the steering arms that are attached to the that are attached to the steering knucklesteering knuckle, tie-

4、, tie-rods and tie-rod ends, adjusting sleeves and rods and tie-rod ends, adjusting sleeves and clampclamps, a center link (s, a center link (relay rodrelay rod or drag link), or drag link), an an idler armidler arm, and a , and a pitman armpitman arm. There are the two . There are the two most comm

5、on types of steering linkage on most common types of steering linkage on passenger cars, shown in Fig.2-4-1 and Fig.2-4-2.passenger cars, shown in Fig.2-4-1 and Fig.2-4-2.linkagelinkage 轉向桿系轉向桿系steering steering knuckleknuckle 轉向節(jié)轉向節(jié)clampclamp 夾箍夾箍relay rodrelay rod 中繼桿中繼桿idler armidler arm 隨動臂隨動臂pi

6、tman armpitman arm 轉向搖臂轉向搖臂Manual Steering Linkage Components (1) Manual Steering Linkage Components (1) 手動轉向傳動機構組成手動轉向傳動機構組成 (1) (1) Fig. 2-4-1 Fig. 2-4-1 1- frame 1- frame （車架）（車架） 2- idler 2- idler arm support arm support （空轉輪臂支架）（空轉輪臂支架） 3- idler arm 3- idler arm （空轉輪臂）（空轉輪臂） 4- 4- sector and se

7、ctor shaft sector and sector shaft （扇（扇形齒輪和齒輪軸）形齒輪和齒輪軸） 5- steering 5- steering shaft shaft （轉向軸）（轉向軸） 6- worm 6- worm gear and ball nut assembly gear and ball nut assembly （蝸輪和球螺母總成）（蝸輪和球螺母總成） 7- 7- pitman arm pitman arm （轉向搖臂）（轉向搖臂） 8- 8- tie-rod (left side) tie-rod (left side) （左轉向（左轉向橫拉桿）橫拉桿） 9-

8、 relay rod 9- relay rod （接力（接力桿）桿） 10- tie-rod (right side) 10- tie-rod (right side) （右轉向橫拉桿）（右轉向橫拉桿） 11- 11- steering knuckle steering knuckle （轉向節(jié)）（轉向節(jié)）Manual Steering Linkage Components (2) Manual Steering Linkage Components (2) 手動轉向傳動機構組成（手動轉向傳動機構組成（2 2） Fig. 2-4-2 Fig. 2-4-2 1- steering knuckle

9、 1- steering knuckle （轉向節(jié)）（轉向節(jié)） 2- rack 2- rack （齒條）（齒條） 3- pinion 3- pinion （轉向齒輪）（轉向齒輪） 4- steering shaft 4- steering shaft （轉向軸）（轉向軸） 5- tie-rod (left side) 5- tie-rod (left side) （左轉向橫拉桿）（左轉向橫拉桿） 6- support6- support（支承）（支承） 7- tie-rod (right side) 7- tie-rod (right side) （右轉向橫拉桿）（右轉向橫拉桿） nOther

10、 types of linkage arrangements are used Other types of linkage arrangements are used on older cars and on trucks. The wheel on older cars and on trucks. The wheel assembly, including the steering knuckle, assembly, including the steering knuckle, pivotpivots at the s at the ball jointsball joints al

11、lowing the front allowing the front wheels to turn to the right or to the left.wheels to turn to the right or to the left.n The steering arms that are attached to the The steering arms that are attached to the steering knuckle turn the wheels to right or steering knuckle turn the wheels to right or

12、left as the linkage moves left as the linkage moves from side to sidefrom side to side. .nThe outer ends of the tie rods are attached The outer ends of the tie rods are attached to the steering arms and the inner ends to to the steering arms and the inner ends to the center link. Threaded adjusting

13、sleeves the center link. Threaded adjusting sleeves between the outer tie rod end and tie rod between the outer tie rod end and tie rod connect the two and provide a means of connect the two and provide a means of adjusting tie rod length. Adjusting sleeves adjusting tie rod length. Adjusting sleeve

14、s are are splitsplit for ease of adjustment and are for ease of adjustment and are clampclamped at each end. The clamps provide a ed at each end. The clamps provide a means of preventing the sleeves from turning means of preventing the sleeves from turning on the rods during vehicle operation. The o

15、n the rods during vehicle operation. The inner ends of the two tie rods are attached inner ends of the two tie rods are attached to the center link by means of to the center link by means of tie rod endstie rod ends. .pivotpivot 轉軸轉軸ball jointsball joints 球形接頭球形接頭from side from side to sideto side 從

16、一端到從一端到另一端另一端splitsplit 開口開口clampclamp 夾緊夾緊tie rod tie rod endsends 橫拉桿接橫拉桿接頭頭nThe center link is supported at one end by the The center link is supported at one end by the idler arm and at the other by the pitman arm. The idler arm and at the other by the pitman arm. The pitman arm pitman arm swing

17、swings through an s through an arcarc from side to side, from side to side, as does the idler arm, when the steering wheel is as does the idler arm, when the steering wheel is turned from right to left and back.turned from right to left and back.nThe idler arm is bolted to the frame on the right The

18、 idler arm is bolted to the frame on the right side of left-hand-drive vehicles. The pitman arm side of left-hand-drive vehicles. The pitman arm is attached to the sector shaft of the steering is attached to the sector shaft of the steering gear with a nut and lock washer.gear with a nut and lock wa

19、sher.n Manual-steering gears Manual-steering gearsnThe steering gear provides the means of converting The steering gear provides the means of converting the turning of the steering wheel to the turning of the steering wheel to side-to-side side-to-side movement of the steering linkage. On some vehic

20、les movement of the steering linkage. On some vehicles the steering gear converts the turning of the the steering gear converts the turning of the steering wheel to steering wheel to fore-and-aftfore-and-aft movement of the movement of the pitman arm, which is then converted to side-to-pitman arm, w

21、hich is then converted to side-to-side linkage movement by a specially shaped side linkage movement by a specially shaped steering arm. The steering gear is bolted to the steering arm. The steering gear is bolted to the frame. The most common type of manual-steering frame. The most common type of ma

22、nual-steering gears are the re-circulating-ball type, shown in gears are the re-circulating-ball type, shown in Fig.2-4-3.Fig.2-4-3.swingswing 擺動擺動arcarc 弧弧side-to-side-to-sideside 左右的左右的fore-fore-and-and-aftaft 前后前后Phantom View of Re-circulating Ball Type of Phantom View of Re-circulating Ball Type

23、 of Manual-Steering Gear Manual-Steering Gear （循環(huán)球式手動轉向器的透視圖）（循環(huán)球式手動轉向器的透視圖） Fig. 2-4-3Fig. 2-4-3 1- sector shaft 1- sector shaft adjusting screwadjusting screw（齒扇軸調整螺釘）（齒扇軸調整螺釘） 2- 2- sector gearsector gear（齒扇）（齒扇） 3- ball nut3- ball nut（球螺（球螺母）母） 4- steering shaft bearing 4- steering shaft bearing

24、 adjusting lock nutadjusting lock nut（轉向軸軸承調整鎖緊（轉向軸軸承調整鎖緊螺母）螺母） 5- steering shaft5- steering shaft（轉向軸）（轉向軸） 6- steering shaft bearing adjuster6- steering shaft bearing adjuster（轉（轉向軸軸承調整器）向軸軸承調整器） 7- upper steering 7- upper steering shaft bearingshaft bearing（上轉向軸軸承）（上轉向軸軸承） 8- ball 8- ball return

25、guide clampreturn guide clamp（鋼球導管夾）（鋼球導管夾） 9- 9- ball return guidesball return guides（鋼球導管）（鋼球導管） 10- 10- lower steering shaft bearing cuplower steering shaft bearing cup（下轉（下轉向軸軸承座）向軸軸承座） 11- mounting hole11- mounting hole（安裝（安裝孔）孔） 12- sector shaft bearing12- sector shaft bearing（齒扇軸（齒扇軸軸承）軸承） 13

26、- spines for pitman arm13- spines for pitman arm（搖（搖臂軸花鍵）臂軸花鍵） 14- sector shaft14- sector shaft（齒扇軸）（齒扇軸） 15- worm gear15- worm gear（蝸輪）（蝸輪） 16- housing16- housing（殼（殼體）體） 17- shim17- shim（墊片）（墊片） nTurning the steering wheel on a vehicle equipped with Turning the steering wheel on a vehicle equipped

27、 with a re-circulating-ball type of steering gear turns the a re-circulating-ball type of steering gear turns the grooved grooved worm shaftworm shaft in the gear. Turning the grooved in the gear. Turning the grooved worm shaft causes the ball nut to thread its way up worm shaft causes the ball nut

28、to thread its way up or down the worm. The teeth of the ball nut push or down the worm. The teeth of the ball nut push nagainst the sector shaft teeth as the worm shaft is against the sector shaft teeth as the worm shaft is turned. The sector shaft teeth and sector shaft are turned. The sector shaft

29、 teeth and sector shaft are integralintegral. As the sector shaft teeth move back and . As the sector shaft teeth move back and forth, the sector shaft is also forced to turn back forth, the sector shaft is also forced to turn back and forth. This causes the pitman arm to move from and forth. This c

30、auses the pitman arm to move from side to side to side to side to actuateactuate the linkage. the linkage.nThe steering gear also provides a gear reduction. The steering gear also provides a gear reduction. This is needed to reduce the amount of effort This is needed to reduce the amount of effort r

31、equired to turn the steering wheel, particularly required to turn the steering wheel, particularly when parking. During straight-ahead driving, this when parking. During straight-ahead driving, this also reduces the possibility of also reduces the possibility of over steeringover steering. This . Th

32、is gear reduction is known as steering gear ratio. gear reduction is known as steering gear ratio. Ratios vary considerably, depending largely on Ratios vary considerably, depending largely on vehicle size and weight. Larger, heavier vehicles vehicle size and weight. Larger, heavier vehicles require

33、 a greater reduction in manual steering gears. require a greater reduction in manual steering gears. The steering gear also absorbs much of the road shock, The steering gear also absorbs much of the road shock, which tends to turn the front wheels right or left.which tends to turn the front wheels r

34、ight or left.worm worm shaft shaft 蝸桿軸蝸桿軸integraintegral l 整體的整體的actuateactuate 驅動驅動over over steerinsteering g 過度轉過度轉向向n(2)(2) Power steering Power steeringnThe power steering unit is designed to reduce the amount The power steering unit is designed to reduce the amount of effort required to turn t

35、he steering wheel; it also of effort required to turn the steering wheel; it also reduces driver reduces driver fatiguefatigue and increases safety by providing and increases safety by providing nbetter control on rough road surfaces or during tire better control on rough road surfaces or during tir

36、e nfailure.failure.nThe system includes a pump driven by a belt from the The system includes a pump driven by a belt from the crankshaft pulley. This pump provides the fluid pressure crankshaft pulley. This pump provides the fluid pressure and flow needed to operate the system. Maximum pressure and

37、flow needed to operate the system. Maximum pressure is controlled by a pressure-regulating valve in the pump. is controlled by a pressure-regulating valve in the pump. A pressure line and a return line connect the pump to A pressure line and a return line connect the pump to the system. Three types

38、of power-steering pumps are used. the system. Three types of power-steering pumps are used. All operate similarly and differ mainly in rotor design. All operate similarly and differ mainly in rotor design. Some pumps have rollers; others have Some pumps have rollers; others have slipperslippers or s

39、 or vanevanes.s.nThe integral type of power-steering unit combines, all The integral type of power-steering unit combines, all in a single assembly, the power piston and cylinder with in a single assembly, the power piston and cylinder with the steering gear and flow control valve. Typical the steer

40、ing gear and flow control valve. Typical integral power-steering gear components are shown in Fig. integral power-steering gear components are shown in Fig. 2-4-4. Power steering provides most of the force needed 2-4-4. Power steering provides most of the force needed for steering. The remaining ste

41、ering effort provides for steering. The remaining steering effort provides needed driver feel for good steering control.needed driver feel for good steering control. fatigue fatigue 疲勞疲勞 slippslipperer 滑塊滑塊 vanevane 葉片葉片 Cross-Section View of Spool-Valve Type of Cross-Section View of Spool-Valve Typ

42、e of Integral Power Steering GearIntegral Power Steering Gear（滑閥式整體動力轉向器的剖視圖）（滑閥式整體動力轉向器的剖視圖） Fig. 2-4-4Fig. 2-4-4 1- oil outlet (1- oil outlet (出油口出油口) 2- oil inlet ) 2- oil inlet ( (進油口進油口) 3- spool valve () 3- spool valve (滑閥滑閥) 4- ) 4- pivot lever (pivot lever (轉軸桿轉軸桿) 5- reaction ) 5- reaction

43、spring (spring (反作用彈簧反作用彈簧) 6- steering ) 6- steering column connection (column connection (轉向柱連接端轉向柱連接端) 7- ) 7- worm shaft balancing ring (worm shaft balancing ring (蝸桿軸平衡蝸桿軸平衡環(huán)環(huán)) 8- right turn reaction ring () 8- right turn reaction ring (右右轉反作用環(huán)轉反作用環(huán)) 9- center thrust bearing ) 9- center thrust

44、bearing race (race (中央止推軸承座圈中央止推軸承座圈) 10- left ) 10- left turn reaction ring (turn reaction ring (左轉反作用環(huán)左轉反作用環(huán)) ) 11- cylinder head (11- cylinder head (缸蓋缸蓋) 12- worm ) 12- worm shaft (shaft (蝸桿軸蝸桿軸) 13- pitman arm () 13- pitman arm (搖臂搖臂) ) 14- power piston (14- power piston (動力缸活塞動力缸活塞) 15- ) 15-

45、left turn power chamber (left turn power chamber (動力缸左腔動力缸左腔) ) 16- re-circulating ball guide (16- re-circulating ball guide (循環(huán)球循環(huán)球導管導管) 17- right turn power chamber ) 17- right turn power chamber ( (動力缸右腔動力缸右腔) )n2. Power Steering Gear( Shown in Fig.2-4-5) 2. Power Steering Gear( Shown in Fig.2-4-

46、5) DisassemblyDisassemblyn(1)(1) Rack support cover removal Rack support cover removalnUsing special tool, remove the Using special tool, remove the rackrack support cover support cover from the gear box.from the gear box.n(2)(2) Lower oil seal/pinion and valve assembly removal Lower oil seal/pinion

47、 and valve assembly removalnUsing a plastic hammer, gently Using a plastic hammer, gently taptap the pinion to the pinion to remove it.remove it.n(3)(3) Seal ring removal Seal ring removalnCaution: When cutting the seal ring, be careful not Caution: When cutting the seal ring, be careful not to dama

48、ge the pinion and valve assembly or the rack.to damage the pinion and valve assembly or the rack.nCut the seal ring and remove it from the pinion and Cut the seal ring and remove it from the pinion and valve assembly and the rack.valve assembly and the rack.n(4)(4) Upper bearing/upper oil seal remov

49、al Upper bearing/upper oil seal removalnUsing a Using a socketsocket, remove the oil seal and the ball , remove the oil seal and the ball bearing from the valve housing simultaneously.bearing from the valve housing simultaneously.n(5)(5) CirclipCirclip removalremovalnTurn the rack stopper clockwise

50、until the end of the Turn the rack stopper clockwise until the end of the circlip comes out of the slot in the rack housing.circlip comes out of the slot in the rack housing.rackrack齒條齒條taptap敲擊敲擊socketsocket套筒套筒circlipcirclip彈性擋彈性擋圈圈Power Steering Gear ComponentsPower Steering Gear Components（動力轉向器

51、的組成）（動力轉向器的組成） Fig. 2-4-5 Fig. 2-4-5 1- gear mounting rubber 2- gear 1- gear mounting rubber 2- gear housing mounting bushing 3- feed pipe housing mounting bushing 3- feed pipe 4- o-ring 5- jam nut 6- tie rod end 4- o-ring 5- jam nut 6- tie rod end 7- clip 8- band 9- bellows 10- tie 7- clip 8- band

52、9- bellows 10- tie rod 11- tab washer 12- coil spring rod 11- tab washer 12- coil spring 13- lock nut 14- rack support cover 13- lock nut 14- rack support cover 15- support spring 16- rack support 15- support spring 16- rack support 17- end plug 18- lock nut 19- valve 17- end plug 18- lock nut 19- v

53、alve housing assembly 20- lower oil seal housing assembly 20- lower oil seal 21- pinion and valve assembly 22- 21- pinion and valve assembly 22- seal ring 23- upper bearing 24- seal ring 23- upper bearing 24- upper oil seal 25- valve housing 26- upper oil seal 25- valve housing 26- circlip 27- rack

54、stopper 28- rack circlip 27- rack stopper 28- rack bushing 29bushing 29，36- oil seal 30- o-ring 36- oil seal 30- o-ring 31- rack assembly 32- seal ring 33- 31- rack assembly 32- seal ring 33- o-ring 34- lower ball bearing 35- o-ring 34- lower ball bearing 35- needle bearing 37- gear housingneedle be

55、aring 37- gear housingnTurn the rack stopper counterclockwise to Turn the rack stopper counterclockwise to remove the circlipremove the circlipn(6)(6) Rack stopper/rack Rack stopper/rack bushing/oil seal/o-bushing/oil seal/o-ring/rack assembly removalring/rack assembly removalnPull out the rack assembly carefully and Pull out the rack assembly carefully and take out the rack take out the rack stopperstopper, rack bush, oil , rack bush, oil seal andseal andn O-ring at the same time. O-ring at the same time.nBend a portion of the oil seal to remove it Bend a portion of the oil seal to remo