8.3. Differentials, power shafts / half shafts
This Part is devoted to the components serving for perception of torque from driveshafts (see Driveshafts) and transfers to its driving wheels of forward and back axes of the car.
The design of forward and back differentials is presented on the following illustrations:
Zadny Bridge of the car has a gipoidny design of the semi-unloaded type (the axis of the leading gear wheel passes below an axis of the conducted gear wheel of the main transfer). During commission of turns the differential provides to an external wheel a possibility of rotation with greater speed, than the speed of rotation of an internal wheel. The internal ends of half shafts are equipped with the vents entering gearing with vents of naves of side gear wheels of differential, therefore, during commission of turns internal (on turn radius) the side gear wheel also rotates more slowly than external. Planetary assembly at the same time begins to rotate in a differential box. The differential is placed in the cast case equipped with a stamped cover and which received the name of the holder. Steel pipes of half shafts are pressed in the holder and scalded.
On some models the back bridge is equipped with the blocked differential of limited sliding (LSD). Such differential works in the mode of usual planetary assembly until one of wheels does not begin to revolve. Pair of conic couplings which are slowing down rotation of a box of differential in a similar situation are a part of assembly. The difference of angular speeds of rotation of wheels taking place leads to increase of load of satellites of planetary assembly which via the conic coupling jointed with a half shaft is transferred to the wheel which is in gearing with a paving.
Forward suspension bracket completely independent. The bridge is formed by assembly of differential and couple of power shafts equipped since both ends with the hinges of equal angular speeds (HEAS). The CV JOINT are placed in rubber protective covers. Internal the pribolchena CV JOINT to the sliding flanges equipped with vents entering gearing with side gear wheels of differential of forward main transfer external is fixed on a shaft pin by means of lock rings.
Often suspicions on failure of components of one of bridges are unreasonable, and a source of emergence of the symptoms taking place lies in violation of serviceability of functioning absolutely of other components of the car. Try to assess with all attentiveness a situation, serially excepting all possible causes of failure.
Emergence of the listed below characteristic foreign sounds often mistakenly is associated with violation of serviceability of functioning of the drive of wheels:
- The noise caused by friction of a protector about a paving surface. Compare the noise background arising at movement along roads with a different covering. Besides, road noise does not change at the movement on transfer and a setup;
- The noise published during the operation of the engine and transmission are well carried out by components of the transmission line finding in gearing with these units. Try to remember engine turns at which noise reach the maximum intensity, then park the car, transfer transmission to neutral situation and accelerate the engine to the same turns — if sounds renew, therefore, the drive of wheels has no relation to their emergence.
In view of need of use of special tools, performance of recovery repair of differential will be more correct to be charged to specialists of car service. Descriptions of procedures of removal and installation of half shafts / power shafts, replacements of epiploons of differential, replacement of bearings and dismantle of all assembly of the drive of wheels for the purpose of performance of its recovery repair or replacement are provided in the following sections of the present Chapter.
When replacing assembly of the back bridge it is necessary to use information which is contained in the identification code which is beaten out from the forward party of the right section of a case of assembly. By a code the permissible load is defined on the bridge, differential type, date and the place of production of assembly.
Design of forward differential
Design of 2-satellite back differential
Design of 4-satellite back differential
Design of differential of limited sliding (LSD)