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Pic. 20 Transmission scheme: 1. Back cover; 2. Drive gear V gear; 3. Gearbox housing; 4. Drive gear IV gear; 5. Retainer ball; 6. Detent spring; 7. Retainer cracker; 8. Drive gear III gear; 9. Drive gear II gear; 10. Reverse drive gear; 11. Drive gear 1st gear; 12. Clutch housing; 13. Transmission input shaft; 14. Main gear drive; 15. Secondary shaft; 16. Axis of satellites; 17. Satellite; 18. Side gear; 19. Half shaft seal; 20. Speedometer drive gear; 21. Differential box; 22. Driven gear of the main gear; 23. Gear selection rod; 24. Gear selector rod lever; 25. Three-arm gear selector; 26. Reverse fork lock; 27. Reverse fork; 28. Reversing light switch; 29. Intermediate reverse gear; 30. Axis of an intermediate gear wheel of a backing; 31. Adjusting ring; 32. Driven gear of the 1st gear; 33. Sliding clutch for switching I. II gears and reverse; 34. Driven gear II gear; 35. Driven gear III gear; 36. The blocking ring of the synchronizer of III and IV transfers; 37. The hub of the synchronizer coupling of III and IV gears; 38. Sliding clutch synchronizer III and IV gears; 39. Driven gear IV gear; 40. Driven gear V gear; 41. Sliding clutch synchronizer V transmission; A - protrusion of the blocking ring; a, b, c - gaps; I. The scheme of the synchronizer; II. Neutral position; III. The beginning of the inclusion of IV gear; IV. Completion of the alignment of the angular velocities of the gear 39 and shaft 15; V. Full engagement of IV gear.
To improve the performance of the car, reduce fuel consumption in mechanical speed gearboxes, first of all, rational selection of the number of gears, gear ratios, as well as improving the quality of the gear shift process are taken into account. At the same time, the latter is of great importance, since the smoothness of gear shifting ensures an increase in the reliability of vehicle components and a decrease in driver fatigue. To do this, all forward gears in the gearbox are synchronized.
The principle of operation of the synchronizer is based on the alignment of the frequencies of rotation of the secondary shaft and the gears of constant mesh freely rotating on it. The figure on the right shows the principle of operation of the synchronizer when the IV gear is engaged in the following position of the clutch:
I. In the neutral position of the clutch 38, the retainer 7 crackers are in the center of the grooves of the hub 37 and do not act on the blocking rings 36. There is a uniform lateral clearance between the protrusions A of the blocking ring and the grooves of the hub "V", and between the protrusions A and crackers 7 - a gap "With" (see "Synchronizer operation").
II. When turning on the IV gear, the sliding clutch, moving towards the gear 39, carries along the crackers 7, which abut against the protrusions A of the blocking ring, i.e. gap "With" is selected. With further movement of the clutch, the crackers press the blocking ring against the conical surface of the synchronizer ring of gear 39. Under the action of friction forces between the conical surfaces of the blocking ring and the synchronizer ring and the inertia of the synchronized masses, the blocking ring rotates relative to the hub until the ring protrusions stop against the side walls of the hub grooves, i.e.. gap "V" is chosen, and on the other hand is doubled.
III. Due to the circumferential displacement of the blocking ring by 1/4 step, the side bevels of the sliding sleeve abut against the side bevels of the blocking ring, and further axial movement of the sliding sleeve 38 stops until the angular speeds of the gear 39 of the IV gear and the output shaft 15 are equal. the friction cones of the blocking ring and gear 39 stop, as a result of which the force that presses the beveled surfaces of the teeth of the coupling and ring disappears.
IV. The freed clutch is easily connected to the crown of the blocking ring, and then to the synchronizer crown, connecting it to the hub.
When the gear is fully engaged, the gaps between the crackers and the protrusions A of the blocking ring and the grooves of the hub are restored.
The figure on the left shows the torque transmission diagrams when all gears are engaged.
When the gear lever is in neutral, the engine is running and the clutch is engaged, the torque from the engine is transmitted through the clutch to the input shaft 13 of the gearbox. From the input shaft drive gears, the torque is transmitted to the secondary shaft gears of the same name, which, having no direct connection with the secondary shaft, will rotate freely on it. Torque is not transmitted to the main gear and differential.
When the 1st gear is engaged, the sliding clutch 33 of the synchronizer, moving towards the gear 32, connects the synchronizer ring of the 1st gear gear with the synchronizer hub, rigidly connected to the output shaft. Torque from gear 32 is transmitted through the clutch to the synchronizer hub and from it to the output shaft. Through gears 14 and 22, the torque is transmitted to the differential. The differential box, rotating together with the axis of the satellites, distributes the torque to the front wheel drives through the teeth of the satellites and side gears.
When the second gear is engaged, the clutch 33 connects the driven gear 34 of the second gear with the synchronizer hub, and the torque from the gear 34 through the sliding clutch 33 is transmitted to the synchronizer hub and to the output shaft.
The third and fourth gears are switched on by a different synchronizer. When turning on the third gear, the clutch 38 connects the gear 35 with the synchronizer hub, and when the fourth gear is turned on, the gear 39 with the hub of the same synchronizer. Torque is transmitted through the connected gear and hub to the output shaft. Similarly, the V transmission synchronizer clutch 41 connects the gear 40 to the synchronizer hub, and through it to the secondary shaft.
Reverse gear is engaged with the car completely stopped. When reverse is selected, the gear lever is moved to the left as far as it will go with increased resistance and forward. In this case, the reverse gear 29 connects the reverse drive gear of the input shaft with the ring gear of the sliding clutch 33 of the synchronizer of I and II gears. Due to the intermediate gear, the transmitted torque changes its direction. Simultaneously with the reverse gear, the reverse light is turned on, since the plug 27 presses the reverse switch rod, and the lamp circuit is connected to the current source.
A clear separation of the lines of III-IV gears and reverse is achieved by a spring latch 44 (see fig. 17), which provides a sharp increase in the reverse gear selection force at the beginning and its fall at the end of the selection stroke.
Gearbox parts are lubricated by spraying oil on the gear rims of the gears. To improve the lubrication conditions of the needle bearings of the gears of the output shaft, radial holes are drilled in the gears between the gear rims, through which oil is supplied to the bearings.