Synchronizer of the fourth and fifth gears of the gearbox of a Kamaz car
The synchronizer of the fourth and fifth gears (Fig. 1) consists of a synchronizer carriage 2, two friction rings 1 and 4, eight blocking fingers 3 and eight latches, consisting of springs 6 and crackers 5 latches.
The synchronizer carriage is machined in the form of a ring along the outer diameter, with which it enters the slots of the gearshift fork legs.
Eight blind radial holes are made around the circumference in the ring, designed to install springs 6 and crackers 5 clamps.
Perpendicular to the blind holes, there are eight holes in the circumference of the ring for installing blocking fingers, and the axes of these holes intersect.
The holes for the locking fingers on both sides are chamfered with an angle corresponding to the angle of the chamfers of the locking fingers.
The carriage has internal and external gear rims. The inner rims are designed to move the carriage along the output shaft.
In addition, these rims, complete with four rims of the output shaft, when the fourth or fifth gear is engaged, form a “lock” that prevents the gear from self-switching off while the vehicle is moving.
Outer crowns are made in two diameters.
A ring gear of smaller diameter is used to connect with the internal gear ring of the input shaft and thus to engage the fifth (direct) gear.
The large diameter ring gear is designed to connect with the gear ring of the fourth gear of the output shaft.
Friction rings 1 and 4 have an inner conical surface, on which a helical groove is cut to squeeze out lubricant when in contact with the cone of the input shaft or gear.
The friction rings are pressed onto the outer ends of the blocking fingers until they stop at their ends. Locking fingers 3 simultaneously act as locks.
In the neutral position, crackers 5 enter the grooves of the fingers under the action of springs 6. Force must be applied to move the carriage out of the middle position.
When any gear is engaged, the blocking fingers first play the role of detents and move the friction rings until they come into contact with the corresponding cone (shaft or gear).
When a moment of friction occurs, the carriage rotates relative to the fingers and they begin to act as blocking ones: the chamfers of the holes rest against the chamfers of the fingers, and the movement of the carriage stops.
After equalizing the peripheral speeds, the fingers take a neutral position, the carriage moves under the action of the gear fork in the direction of the gear to be engaged. At the same time crackers 5 are recessed, compressing springs 6.
The first gear is engaged by moving the carriage of the first gear and reverse along the slots of the first gear bushing back until it is connected to the ring gear of the first gear (Fig. 2).
In this case, the torque from the input shaft of the gearbox is transmitted to the gear of the intermediate shaft drive and then to the gear of the first gear of the secondary shaft, which is rigidly connected to it through the included carriage and bushing.
The second gear is engaged by moving the synchronizer carriage of the second and third gears along the splines of the secondary shaft back until it engages with the ring gear of the second gear of the secondary shaft.
In this case, the gear of the second gear of the secondary shaft through the synchronizer carriage is blocked with it and transmits torque from the gear of the second gear of the intermediate shaft.
The third gear is engaged by moving the synchronizer carriage of the second and third gear along the splines of the secondary shaft forward until it engages with the ring gear of the third gear of the secondary shaft.
In this case, the gear through the carriage is blocked with the shaft.
The fourth gear is engaged by moving the synchronizer carriage of the fourth and fifth gears along the splines of the output shaft back until it engages with the ring gear of the fourth gear of the output shaft.
Fifth gear is engaged by moving forward the synchronizer carriage of the fourth and fifth gears along the splines of the secondary shaft until it is fully connected to the gear rim of the input shaft.
In this case, the torque from the input shaft through the synchronizer carriage is directly transmitted to the secondary shaft.
Reverse gear is engaged by moving the first gear carriage and reverse gear along the splines of the first gear bushing forward until it is connected to the reverse gear ring gear, which is engaged with the reverse gear block.