Tài liệu học tập cơ bản khái quát về động cơ và các bộ phận trên ô tô phiên bản tiếng anh. Tài liệu này nhằm giúp chúng ta tiếp cận được cấu tạo chức năng của các bộ phận của xe. Với tài liệu này giúp các bạn sinh viên ngành cơ khí ô tô tiếp cận được những kiến thức cơ bản về ô tô và đồng thời nâng cao kiến thức tiếng anh. Bộ tài liệu này được soạn thảo bởi trường đào tạo và huấn luyện nghề ở Canada
Chapter 46 Steering Systems Manual Steering Systems • Steering system is composed of three major subsystems: – Steering linkage – Steering gear – Steering column and wheel Steering Linkage • Applies to the pivots and connecting parts between the steering gear and steering arms • Transfers motion from the steering gear • The type of front suspension greatly determines the type of linkage Parallelogram Steering Linkage • Once the most common type • Used with the recirculating ball gearbox • Can be placed in front or behind the front suspension • Provides good steering geometry • Road vibrations and impact forces cause wear and looseness Parallelogram Steering Rack-and-Pinion Steering Linkage • Lighter and has fewer components than the parallelogram linkage • The rack performs as steering gear and center link • Tie-rods are the only linkage used • Provides better road feeling but can transmit more road shock Rack-and-Pinion Steering System Manual-Steering Gear • Changes rotational motion of steering wheel into a reciprocating motion to move the wheels • Three types currently in use: – Recirculating ball – Worm and roller – Rack and pinion Recirculating Ball • Found in larger cars, trucks and vans • The ball nut moves the worm gear which moves the sector shaft Steering Wheel and Column • • • • • Provides the force to turn the steering gear Since 1968, all columns are collapsible Houses the driver side air bag May have tilt and/or telescoping features Houses many of the driver operated switches and sometimes the transmission shifter Rack and Pinion Steering • Has only four wear points - the tie-rod ends • Check power units for power steering fluid leaks • Inspect mountings, tie rods, bellows, steering couplings, and gearbox adjustment Steering Gear Adjustments • Carefully inspect steering and suspension components, wheel alignment, wheel balance, and tire pressure • Wormshaft preload and sector gear preload may be adjustable Steering Column • Most services are performed with the column installed in the vehicle • Closely inspect the energy absorbing sections of the column • Inspect couplers and steering shaft Steering Wheel • • • • • • Place front wheels straight ahead Disconnect battery negative cable Remove steering pad and retaining nut Place alignment marks on shaft and wheel Disconnect electrical connectors Use correct puller and remove wheel Bleeding the System • Performed after replacing any system hydraulic part • Follow service manual procedures • A vacuum pump can be used to purge air • Often running the engine and turning the steering from stop to stop will remove the air Hoses and Lines • Inspect for leaks, dents, sharp bends, cracks, and swelling • Use exact replacements • Do not attempt to patch or repair • Ensure lines and hoses not rub against other components Power Steering Pump • Pulleys may be replaced if bent, cracked, or worn • Some require special pullers and installation tools • Flow control valves and pressure relief valves may be replaceable Four-Wheel Steering Systems • Mechanical 4WS – A steel shaft connects the two gearboxes • Hydraulic 4WS – Rear wheels turn in same direction as the front • Electro/hydraulic 4WS – Rear wheels can turn with or opposite front – Uses computer monitoring and control Air Bag Safety Precautions • Always wear safety glasses • Follow the manufacturer’s procedure for disarming the system before servicing • Never probe the connectors on the air bag module • Always carry an air bag module with the trim facing away from your body Air Bag Safety Precautions (Cont’d) • Never set a live air bag module down with the trim cover facing down • Wash your hands with soap and water after working around a deployed air bag ...Manual Steering Systems • Steering system is composed of three major subsystems: – Steering linkage – Steering gear – Steering column and wheel Steering Linkage • Applies... parts between the steering gear and steering arms • Transfers motion from the steering gear • The type of front suspension greatly determines the type of linkage Parallelogram Steering Linkage... and sometimes the transmission shifter Steering Damper • Reduces road shock up through the steering column • Found mostly on 4WD vehicles Power Steering Systems • Reduce driver effort • Major