typical Designs of Vehicle Transmission

typical Designs of Vehicle Transmission‘s The process of human thought proceedv.from the abstract, then back to the concrete/J. DEWEY, 1910/ This chapter examines some particular transmission designs, and considers their structural design. You may refer to the gearbox diagrams in Chapter 6 with regard to the gearwheel configurations in the transmissions examined. This applies particularly to multirange transmissions. Sections 12.1 to 12.4 are devoted to manual passenger car and commercial vehicle gearboxes. Sections 12.5 to 12.7 cover final drives, differential gears, transfer boxes and all-wheel power trains. Table 12.1 gives an overview of the selector boxes discussed. Each gearbox is allocated !~a serial number. At the beginning of Sections 12.5 and 12.6 there are summaries of the designs covered in the sections. Table 12.1 .Vehicle transmissions examined in Sections 12.1一12.4. TCC Torque converter clutch; CC Torque converter lock-up clutch Serial No. Vehicle Gears Characteristic Manufacturer Designation Diagram Fig.No Design Fig.No 1 Passenger car 5 Two-stage manual shift ZF S 5-31 6.19b 12.1-3 2 Passenger Car 6 Two-stage manual shift Getrag 6-speed 6.20a 12.4 3 Passenger Car 5 Single-stage manual shift Vw MQ 6.18b 12.5 4 Passenger Car 6 Single-stage manual shift Opel F28-6 6.20b 12.6 5 Commercial vehicle 6 Single-stage manual shift ZF S6-66 6.36b 12.7 6 Commercial Vehicle 16 Three-stage manual shift ZF 16 S 109 6.44 12.8 7 Commercial Vehicle 13 Three-stage manual shift Eaton Twin splitter 6.45 12.9 8 Commercial vehicle 16 TCC, with CC, with retarder ZF Transmatic 6.47 12.10 12.11 9 Passenger Car 5 Conv. Automatic without CC MB W5A 030 - 12.12 10 Passenger Car ∞ Continuously variable transmission Ford CTX 6.32 12.13                 Serial No. Vehicle Gars Characteristic Manufacturer Designation Diagram Fig.No Design Fig.No 11 Commercial Vehicle 6 Conv. Automatic without CC ZF 6 Hp 600 6.48 12.14 12 Commercial Vehicle 6 Conv. Automatic without CC modulation cluth transter box Renk HSRM 226.22 - 12.15 13 Passenger Car 5 Single-stage Manual shift Automatic master box MB Luk SG 150 EKM - 12.16a 14 Passenger Car 5 Countershaft-type Automatic with CC MB W5A 180 - 12.16b 15 Passenger Car 5 Conv. Automatic without CC MB W5A 580 - 12.16c 16 Passenger Car 5 Conv.automatic ZF 5 Hp 18 6.29 12.17 17 Commercial Vehicle 16 Three-range, Two countershaft Semi-automatic ZF 16AS 2600 - 12.18                 12.1 Manual Gearboxes 12.1.1 Manual Passenger Car Gearboxes 4-speed manual gearboxes were standard for passenger cars in Europe until the early 1980's. As engine power and vehicle weight increased and cw ratings improved, larger overall gear ratios became necessary. Large overall gear ratios facilitate moving off, provide good acceleration, and also reduce engine speed and hence fuel consumption at high speeds. Manual gearboxes therefore now usually have five speeds. Sometimes 6-speed gearboxes are now used in "high-performance" passenger cars. 1/ Two-Stage 5-Speed Manual Passenger Car Gearbox; ZF S 5-31 Figure 12.1 shows a two-stage 5-speed passenger car countershaft-type manual gearbox with direct drive in fifth gear. In this design, first and second gear are roughly in the middle of the main shaft. This contravenes the principle whereby gear steps with higher torque conversion should be located as close as possible to a main bearing (Section 8.2 "General Design Guidelines"). But the resultant shaft deflection can be controlled by appropriate gearing geometry. The advantage of this structural design is that the more frequently used gear steps of third and fourth gear are near a bearing point, making them run more quietly. In contrast to in一line gearboxes, where all synchronisers are mounted on the gearbox main shaft, in this gearbox the synchronisers for third and fourth gear are moved to the countershaft. This arrangement means the idler gears and shift gears for third and fourth gear are no longer on the countershaft itself, but linked to the output side. Their speeds thus no longer' have to be matched to the output speed during synchronisation, which reduces the frictional work and shift effort required to change gear. It is not possible to move any more idler gears to the countershaft, since the differential rotational speeds are too great. The synchronisers for first and second gear are of double-taper design, significantly reducing gearshift effort. All other gear steps, including reverse gear, have single-taper synchronisers. Since the idler gears in third and fourth do not rotate when the vehicle is stationary in neutral, they do not produce as much rattle as idler gears mounted on the main shaft (see also Section 7.5) The kinematics of the engagement process is shown in rate selector bars for each individual selector fork gear shift forks 5-7. This has weight advantages, selector shaft runs in linear ball bearings 4, which Figure 12.2. Instead of sepa-forks have a pivot 9 supported in the housing,a central selector shaft I is used with and is more cost-effective. The central reduces gear shift effort. The gear shift principle. This enables ratio. In this type of desi around which they pivot on the lever gear shifting effort to be reduced by selecting a suitable lever gn the gear shift forks (or gates) are changed by the shaft turning.