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1. The lower cover of the gearbox. 2. Oil filler plug. 3. Gear wheel of the second transfer of an intermediate shaft. 4. Gear wheel of the third transfer of an intermediate shaft. 5. Intermediate shaft. 6. Bearing of an intermediate shaft. 7. Bolt. 8. Clamping washer of the front bearing of the intermediate shaft. 9. Driven gear of the intermediate shaft. 10. Thrust washer of the fourth gear synchronizer spring. 11. Drive shaft. 12. The front cover of the gearbox with the guide sleeve of the clutch release bearing. 13. Oil seal. 14. Retaining ring. 15. Spring washer. 16. O-ring. 17. Spring washer. 18. Rear bearing of the input shaft. 19. Clutch housing. 20. Transmission housing. 21. Gearbox breather. 22. Drive shaft-gear. 23. Bearing of the front end of the driven shaft. 24. Fourth gear synchronizer ring gear. 25. Retaining ring of the hub of the synchronizer of the third and fourth gears. 26. Spring washer of the synchronizer hub. 27. The hub of the sliding sleeve of the synchronizer. 28. Sliding clutch of the synchronizer. 29. A lock ring of a blocking ring of the synchronizer. 30. Synchronizer blocking ring. 31. Synchronizer spring. 32. Thrust washer. 33. Driven gear of the third gear. 34. Driven gear of the second gear. 35. Driven shaft. 36. Driven gear of the first gear. 37. Sleeve. 38. Intermediate bearing of the driven shaft. 39. Locking plate. 40. Reverse driven gear. 41. Spring washer. 42. Fixing ball. 43. Speedometer drive gear. 44. Rear bearing of the driven shaft. 45. Seal of the driven shaft. 46. Dirt deflector. 47. Flexible coupling flange. 48. Nut of the rear end of the driven shaft. 49. O-ring. 50. Centering ring driveline. 51. Retaining ring. 52. Lock washer. 53. Speedometer drive. 54. Rear cover of the gearbox 55. Reverse fork. 56. Intermediate reverse gear. 57. Reverse drive gear. 58. Rear intermediate shaft bearing. 59. The axis of the intermediate reverse gear. 60. Gear wheel of the first transfer of an intermediate shaft. 61. Cork magnet. 62. Oil drain plug.
The gearbox allows you to change the amount of torque transmitted to the driving wheels of the car, move the car in reverse, disconnect the running engine from the transmission while the car is parked and create the ability to move the car by inertia (coasting) without a running engine.
The four-speed gearbox provides the car with intensive acceleration with good use of engine power and a high average vehicle speed. Used in the gearbox, helical gears of constant meshing of all gears have increased noiselessness and durability. Shockless, and therefore silent, engagement of all forward gears is provided by synchronizers that equalize the rotation speeds of the gears engaged in engagement.
The gearbox consists of a crankcase, a drive shaft with a gear, an intermediate shaft made in the form of a gear block, a driven shaft with gears and synchronizers, an axle with an intermediate reverse gear and a gear shift mechanism.
The cast aluminum crankcase 20 of the gearbox is attached to the clutch housing 19 with its front end. The crankcase is closed from the front with a stamped cover 12, in which a self-clamping rubber seal 13 of the drive shaft is installed. From below, the crankcase is closed with a stamped cover 1 with an oil drain plug 62. A cast aluminum cover 54 is attached to the rear wall of the gearbox housing, which houses the gearshift control mechanism, the speedometer drive, the reverse gears and the rear bearing of the driven shaft. The output of the driven shaft from the box is sealed with a self-clamping rubber gland 45.
The accuracy of the location of the gearbox relative to the clutch housing and the engine crankshaft is ensured by entering the outer ring of the rear bearing 18 of the input shaft into the hole of the clutch housing, centering the clutch housing relative to the engine cylinder block on the pins and installing the front bearing of the input shaft of the gearbox in the socket of the engine crankshaft. The rear end of the drive shaft 11 rotates in a ball bearing 18 pressed into the front wall of the gearbox housing. The bearing adjusting ring keeps it in the crankcase together with the shaft from axial movement. Bearing 18 is locked on the shaft by ring 14. To prevent axial movement of the drive shaft in bearing 18, a Belleville spring washer 15 is placed between the inner ring of the bearing and retaining ring 14, giving an axial force of 120-280 kgf, depending on the combination of part sizes.
The flange of the front cover 12 is clamped between the outer ring of the bearing 18 and the clutch housing with a Belleville spring washer 17 with an axial force of 235-475 kgf, depending on the elasticity of the washer and the combination of the dimensions of the parts.
At the front end of the drive shaft there are splines for connecting it to the clutch disc. There are two gear rims on the back of the drive shaft: one with oblique teeth is cut on the shaft and is in constant engagement with the teeth of gear 9 of the intermediate shaft 5, the second with straight teeth is the crown of the synchronizer and engages with the clutch when the fourth gear is turned on (straight) transmission.
The ring gear 24 of the fourth gear synchronizer is soldered to the drive shaft with copper. Between the drive shaft gear and crown 24 there is a thrust washer 10 of the fourth gear synchronizer spring, made of heat-resistant chromium-nickel steel.
The intermediate shaft 5, made in the form of a block of four helical gears, rotates in a double-row ball 6 and roller 58 bearings. The first gear 9 is in constant engagement with the drive shaft gear. The remaining three gears 4, 3 and 60 are the drive gears of the third, second and first gears.
At the rear end of the intermediate shaft, the reverse drive gear 57 is installed on the splines and fixed with a retaining ring. Between the end face of the gear and the inner ring of the roller bearing of the intermediate shaft, a spring washer of the Belleville type with an axial force of 29.5-48.5 kgf is installed.
The direction and angles of inclination of the teeth of the helical gears in the gearbox are chosen so that when any gear is engaged, the resulting axial forces are directed in opposite directions and partially balance each other.
The driven shaft 35 is mounted on three bearings. The roller bearing 23 of the front end is located in the socket of the input shaft. To lubricate bearing 23 in the input shaft gear, holes are drilled in two opposite depressions between the teeth through which oil from the crankcase enters the bearing.
The intermediate ball bearing 38 of the driven shaft is located in the rear wall of the gearbox housing and is locked from axial movement by an adjusting ring located in the groove of the outer ring of the bearing, and a plate 39 fixed with three screws. The inner ring of the bearing 38 is fixed on the driven shaft together with the reverse driven gear 40, the bushing 37 of the first gear driven gear and the hub of the sliding clutch of the synchronizer of the first and second gears with the help of a retaining ring and Belleville spring washer 41. The axial force of the spring washer 41 is 250-550 kgf.
The rear bearing 44 of the driven shaft is located in the rear cover of the gearbox, and is fixed on the shaft between the driving gear 43 of the speedometer drive and the flange 47 of the elastic coupling and tightened with a nut 48, which is locked with a lock washer 52.
In the front part of the driven shaft, on both sides of the annular shoulder, small longitudinal grooves are cut to supply lubricant to the rubbing surfaces of the driven gears of the second and third gears and three equally spaced deep grooves, into which the hubs of the synchronizer sliding clutches enter with their protrusions.
The synchronizer hubs of the third and fourth gears are locked on the shaft with a retaining ring 25 with a spring washer 26. The axial force of the spring washer is 260-470 kgf.
Behind the hub on the shaft is a driven gear 33 of the third gear. A spur ring is also made on the gear, on which the locking ring of the synchronizer, its spring and the thrust washer of the spring are fixed with a retaining ring.
Gear 33 rotates freely on a heat-treated shaft journal and is in constant engagement with the drive gear of the third gear of the intermediate shaft. To supply lubricant to the rubbing surfaces in the gear 33 there are radial drilling in the groove between the two rims, a slot on one end and two grooves on the other end.
The driven gear 34 of the second gear is mounted behind the annular shoulder of the shaft and rotates freely on a heat-treated shaft journal. It is in constant engagement with the drive gear of the second gear of the intermediate shaft.
The driven gear 36 of the first gear also rotates freely on a heat-treated steel sleeve 37.
The reverse driven gear 40 is mounted on a segment key in the middle part of the driven shaft behind the intermediate bearing.
At the rear end of the driven shaft, the drive gear 43 of the speedometer drive is installed. The gear 43 is kept from turning by the ball 42, which is installed in the recess of the shaft.
The reverse intermediate gear 56, which has a sleeve on the inner surface, rotates freely on a fixed axle 59 installed in the hole in the rear wall of the crankcase 20 and the lug hole of the rear cover 54. The gear has an annular groove into which the reverse fork 55 enters. When moving the intermediate gear 56 forward, it simultaneously engages with the gear 57 of the intermediate shaft and the gear 40 of the driven shaft, including reverse.
Inertial type synchronizers installed in the gearbox allow you to turn on the first, second or third gear only after the speeds of rotation of the gear of the engaged gear of the output shaft and the intermediate shaft are aligned. The fourth gear is engaged after the speeds of rotation of the driven and driving shafts are equalized.
The synchronizer for two gears consists of a hub 27, a sliding sleeve 28, two bronze locking rings 30, two annular springs 31, their support cups and two stoppers 29 of the locking rings.
On both sides of the hubs 27 there are synchronizer rims with straight involute teeth, rotating independently of the hubs in the neutral position of the shift lever. When any forward gear is engaged, the sliding clutch, moving along the splines of the hub, engages with the crown of one of the driven gears or the crown of the input shaft and connects them. So the driven shaft begins to rotate at the speed of one of the driven gears, which are constantly engaged with the gears of the intermediate shaft, or at the speed of the drive shaft when the fourth gear is engaged.
Blocking rings 30 are put on the gear rims of the synchronizers. The outer conical surface of the blocking rings corresponds to the cones of the sliding clutch. To create increased dry friction during synchronizer operation, a fine thread is cut on this surface, which, at the moment the ring contacts the clutch, breaks the oil film. The internal teeth of the blocking rings, as well as the teeth of the crowns on which they are put on, are pointed. The teeth of the synchronizer clutch have similar bevels.