Subaru Legacy/Outback

1999-2003 of release

Repair and car operation

Interaxal differential - the device and a functioning principle

Design of interaxal differential with вязкостной муфтой


1 — the Conducted gear wheel of the distributing mechanism 2 — the Leading gear wheel of the distributing mechanism 3 — Vjazkostnaja муфта	4 — Interaxal differential with вязкостной муфтой 5 — the Shaft of a leading gear wheel of the main transfer 6 — the Conducted (secondary) shaft

Design вязкостной муфты interaxal differential


1 — the Ring of X-shaped section 2 — the Sealing ring 3 — the Remote ring 4 — the Disk of external gearing	5 — the Disk of internal gearing 6 — the Ring of X-shaped section 7 — the Back lateral gear wheel

The description of procedures of removal, service and installation of interaxal differential is resulted in Section Removal, service and installation of interaxal differential.

Design

The interaxal differential is executed under the planetary symmetric scheme on conic gear wheels. Design feature used on models of interaxal differential considered in the present Management is application вязкостной муфты.

The interaxal differential carries out two functions: distribution of a twisting moment of the engine between power shafts of forward both back wheels and distinction repayment in speeds of rotation of forward and back wheels.

The engine twisting moment is transferred to interaxal differential from a conducted (secondary) shaft of transmission, being distributed then between shaft of a leading gear wheel of the main transfer (directly through conic gear wheels) and карданном shaft (through leading and conducted gear wheels of the distributing mechanism).

At normal coupling of forward and back wheels with the road covering provided with adequate distribution of twisting moments working function of conic gear wheels of differential it is limited вязкостной муфтой.

In the case вязкостной муфты the disks (plates) of external and internal gearing located serially are established some. In tightly closed cavity, образуемую the case and a back lateral gear wheel of differential, fill in an air-silicone oil mix.

The part of disks муфты is equipped external шлицами, entering into gearing with the case of interaxal differential. On шлицы disks of internal gearing the lateral gear wheel is planted.

For distributing of disks of external gearing between them special remote rings are established. Between disks of internal gearing such rings are not provided that provides certain freedom of their moving in an axial direction.

Two H-shaped sections of a sealant executed in the form of rings, prevent вытекание from муфты silicone oil in case of increase of its pressure at the big difference in speeds of rotation of forward and back wheels.

Functioning principle

Losses of silicone oil вязкостной муфты are fraught with an assemblage exit out of operation! Pressure inside муфты can raise considerably when speeds of rotation of forward and back wheels considerably differ from each other for a long time, for example, during towage of a vehicle with a separation of one of axes from the earth.

Distribution of a twisting moment of the engine at normal movement of the car


1 — an engine Twisting moment A — To forward differential	B — To back differential

In the absence of a difference of speeds of rotation of forward and back wheels the interaxal differential transfers an engine twisting moment to forward and back wheels in the relation 50:50, and at occurrence of such difference, makes its its controllable clearing with the help вязкостной муфты.

At rectilinear movement of a vehicle with constant speed on equal road all wheels rotate with identical speed and the interaxal differential in regular intervals distributes an engine twisting moment between forward and back axes. As disks of external and internal gearing вязкостной муфте remain motionless from each other, the shift moment between them does not arise. During fulfilment of turns at low speeds of movement the difference in speeds of rotation arises not only between right and left, but also and between forward and back wheels, - forward wheels rotate faster the back. A problem of interaxal differential is repayments of the given difference for the purpose of maintenance of smoothness of movement and prolongation of service life of tyre covers. Despite insignificance of a difference of speeds of rotation of wheels in the given conditions, work вязкостной муфты leads to redistribution of a twisting moment of the engine in favour of a back axis.

At movement on rough and slippery roads to a case when forward wheels start to revolve, the general difference between speeds of rotation of forward and back power shafts leads to occurrence in вязкостной муфте considerably the shift moment. As a result, the twisting moment transferred to back wheels, becomes much more, than transferred to scrolled forward wheels.

At sharp dispersal from a place when back wheels are on a slippery surface, occur displacement of the centre of gravity of the car, leading to proslipping of back wheels. In the present state of affairs arising in вязкостной муфте the shift moment leads to redistribution of a twisting moment of the engine in favour of forward wheels.