8.3. Differentials, power shafts / semi-axis
This Part is devoted to the components serving for perception of a 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 below-mentioned illustrations:
Zadny Bridge of the car has a gipoidny design of the semi-unloaded type (the axis of a leading gear wheel passes below an axis of a conducted gear wheel of the main transfer). During commission of turns the differential provides to an external wheel rotation possibility with greater speed, than speed of rotation of an internal wheel. The internal ends of semi-axes are equipped with the shlitsa entering into gearing with shlitsa of naves of lateral gear wheels of differential, therefore, during commission of turns internal (on turn radius) the lateral gear wheel also rotates more slowly than the external. Planetary assembly thus starts to rotate in a differential box. The differential is placed in the cast case which equipped with a stamped cover and has received the name of the holder. Steel pipes of semi-axes are pressed in the holder and scalded.
On some models the back bridge is equipped with the being blocked differential of limited sliding (LSD). Such differential works in a mode of usual planetary assembly until one of wheels does not start to revolve. The structure of assembly includes pair of the conic couplings which are slowing down rotation of a box of differential in a similar situation. The taking place difference of angular speeds of rotation of wheels leads to increase of load of satellites of planetary assembly which via the conic coupling jointed with a semi-axis is transferred on being in gearing with a paving a wheel.
Forward suspension bracket completely independent. The bridge is educated by assembly of differential and pair of the power shafts equipped since both ends with hinges of equal angular speeds (CV JOINT). The CV JOINT are placed in rubber protective covers. Internal the CV JOINT приболчены to the sliding flanges equipped with shlitsa entering into gearing with lateral gear wheels of differential of forward main transfer, external are fixed on a shaft pin by means of lock rings.
Often suspicions on failure of components of one of bridges appear unreasonable, and a source of emergence of taking place symptoms lies in violation of serviceability of functioning absolutely other components of the car. Try to estimate with all attentiveness a situation, serially excepting all possible causes of failure.
Emergence listed below characteristic extraneous sounds often wrongly associates with violation of serviceability of functioning of a drive of wheels:
- The noise caused by a friction of a protector about a surface of a paving. Compare the noise background arising at movement on roads with a different covering. Besides, road noise does not change at movement on transfer and nakaty;
- The noise published at operation of the engine and transmission are well carried out by components finding in gearing with these units of the transmission line. Try to remember engine turns at which noise reach the maximum intensity, then park the car, transfer transmission to neutral situation and disperse 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, it will be more correct to charge performance of regenerative repair of differential to specialists of car-care center. Descriptions of procedures of removal are provided in below-mentioned sections of the present Chapter and installation poluosey/power shafts, replacement of epiploons of differential, replacement of bearings and dismantle of all assembly of a drive of wheels for the purpose of performance of its regenerative repair or replacement.
At replacement of assembly of the back bridge it is necessary to use information containing in an identification code, beaten out from the forward party of the right section of a case of assembly. On a code the permissible load is defined on the bridge, differential type, date and a place of manufacturing 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)