Kinematic diagram of the gearbox (VAZ-2108).
The first gear (Fig. 3.3, a) is switched on by moving the synchronizer clutch 22 to the right with the help of the synchronizer fork and connecting the synchronizer with the driven gear 21 of the first gear freely mounted on the secondary shaft 12. In this case, the torque from the input shaft 2 will be transmitted through the drive gear 10 rigidly mounted on it to the driven gear 21 of the first gear and then through the synchronizer clutch 22, the hub of which is fixed on the splines of the secondary shaft, to the secondary shaft 12 of the gearbox.
The second gear (Fig. 3.3, b) is switched on by moving the synchronizer clutch 22 to the left. In this case, the clutch connects the driven gear 23 of the second gear with the synchronizer hub, and the torque from the drive gear 6 through the clutch 22 is transmitted to the synchronizer hub and to the output shaft 12.
The third and fourth gears (Fig. 3.3, c, d) are switched on by moving the synchronizer clutch 25 to the right or left. In this case, with the help of a synchronizer, the secondary shaft 12 is connected to the driven gear 24 of the third or 26 fourth gear. The torque from the input shaft 2 to the secondary shaft 12 will be transmitted through gears 5 and 24 of the third gear or through gears 4 and 26 of the fourth gear.
The fifth gear (Fig. 3.3, e) is switched on by moving the synchronizer clutch 28 to the right and connecting it to the driven gear 27 of the fifth gear. In this case, the torque will be transmitted from the input shaft to the secondary through the drive 3 and driven 27 gears of the fifth gear and the synchronizer clutch 28, the hub of which is fixed fixedly on the splines of the output shaft.
The reverse gear (Fig. 3.3, e) is switched on by moving to the left the intermediate gear 8 of the reverse gear installed on the axis 9, due to which it is engaged with the drive gear 7 and the ring gear 11 of the clutch 22 of the synchronizer of I and II gears, thereby ensuring the transmission of torque torque from the input shaft to the secondary. With the help of an intermediate gear, the secondary shaft changes the direction of its rotation.
Reverse gear is switched on when the car is completely stopped, since only forward gears have synchronizers. Reverse gears are spur gears.
2. Scheme of a five-speed gearbox of a ZIL-130 car:
Kinematic diagram of a ten-speed gearbox KAMAZ-5320
It consists of a main five-speed gearbox 1 and a front attachment gearbox – divider 2.
The main gearbox is kinematically similar to the previously discussed MAZ gearbox, with the exception of the following:
the inclusion of the first gear and reverse gear is carried out by a gear clutch 11 moving along the splines of the driven shaft 10, in connection with which the gears of the first gear 13 and reverse gear 12 are mounted on the shaft on needle bearings;
• fifth gear is direct;
• transmission drive shaft 7 has splines in its front part, on which a gear coupling 6 with a cone is installed to ensure the operation of the synchronizer 16 of the gear divider.24
The inclusion of the main gears in the box (II … V) is carried out by two synchronizers 8 and 9.
The gear divider is a two-stage gearbox with gear ratios: in the lowest (direct) gear – 1.0 and in the highest (accelerating) – 0.815.
On the drive shaft 5 of the divider is free, on the needle bearing there is a gear 4 with a ring gear and a cone, and on the splines there is a synchronizer 16 for switching on the gears of the divider. Gear 4 is in constant engagement with gear 3 of the intermediate shaft 15 of the divider. The latter, in turn, is rigidly connected to the front end of the intermediate shaft 14 of the gearbox.
In the lower gear of the divider, the synchronizer 16 connects the drive shaft of the divider 5 and the main shaft 7 of the gearbox. In the highest (accelerating) gear of the divider, the torque is transmitted through gears 4 and 3 to the intermediate shaft 14 of the gearbox. The divider synchronizer drive is pneumatic.
4. Kinematic diagram of the transfer case:
: 1 – input shaft with flange, 2 – drive gear, 3 – top hatch cover, 4 – power take-off gear, 5 – power take-off clutch (only for KamAZ-4310), 6 – power take-off (only for KamAZ- 4310), 7 – oil sump, 8 – reduction gear, 9 – fitting, 10 – rear axle drive shaft, // – rear differential cage, 12 – differential epicyclic (crown) gear, 13 – center differential drive gear, 14 – sun gear, 15 – differential housing front, 16 – transfer case housing, 17 – overdrive gear, 18 – transfer case front cover, 19 – plug, 20 – high gear engagement clutch, 21 – differential lock clutch, 22 – drive pinion gear electric speedometer, 23 – front axle drive shaft, 24 – differential lock fork, 25 – pneumatic chamber, 26 – rod, 27 – membrane, 28 – switch, 29 – intermediate shaft, 30 – low gear clutch, 31 – industrial spooky gear
B) VAZ 21213.
5. Scheme of the inertial synchronizer .
The inertial synchronizer consists of three main elements: equalizing and including, like a simple synchronizer;
– blocking – a device that prevents the inclusion of a gear clutch until the angular velocities of the parts to be connected are completely equalized, which ensures shockless and noiseless gear engagement.
Consider some designs of synchronizers used in gearboxes of modern tractors and cars.
The sliders are pressed with their protrusions to the annular groove of the inner surface of the coupling by two spring rings, the bent ends of which are inserted into the groove of one of the sliders. Thus, the elastic fixation of the sliders in the middle part of the coupling is carried out in its neutral position.
Both sides of the synchronizer hub are fitted with brass blocking rings with toothed rims and ends with three longitudinal grooves. The width of the latter is greater than on the grooves of the hub by half the pitch of the teeth. The ends of the sliders enter the grooves of the rings, which ensures their joint rotation.
Thus, the primary and secondary shafts of the gearbox are rigidly connected to each other, which corresponds to the inclusion of the corresponding gear.
In the design, the friction elements are made in the form of conical surfaces on the movable engagement gear clutch and the blocking ring. As blocking elements, the internal teeth of the blocking ring and the end sections of the teeth cut on the gear hub are used. The pinion and blocking ring are elastically connected to each other in the axial direction by means of a compressed spring held by a retaining split ring. This contributes to the installation of structural parts in the initial neutral position and, at the same time, does not prevent the ring from blocking, unlocking it and engaging the gear.
The synchronizer works in the following sequence:
the conical friction surfaces of the coupling and the blocking ring approach each other;
the ring is blocked and, consequently, the clutch;
the angular velocities of the clutch and gear are aligned;
the ring is unlocked and the clutch, moving in the axial direction, is included in the full length of the teeth.
The design of the synchronizer differs from those previously considered, mainly in the design of the blocking element. Let’s consider its design in more detail. The synchronizer body is made in the form of a cylinder with internal cones at the ends, mounted on the disk of the including clutch and held on it by conical clamps placed in the radial holes of the disk. The coupling is mounted on a toothed shaft sleeve and is moved by means of a ring and pins. Inertial disk synchronizer with blocking fingers: blocking finger; multi-plate friction clutches. They are sometimes used in gearboxes on high power tractors and heavy vehicles to engage lower gears.
It should be noted that the latches in inertial synchronizers play an auxiliary role and their springs should only provide centering of the housing and setting the initial friction moment in the leveling element to ensure rotation of the housing and turn on the synchronizer blocking device.
6 . Scheme of the pneumatic control system of the divider.