Astra HD8Ec Посібник - Сторінка 5
Переглянути онлайн або завантажити pdf Посібник для Підйомні системи Astra HD8Ec. Astra HD8Ec 15 сторінок.
Друкувати сторінкуASTRA HD8Ec
DESCRIPTION
The ZF 16S 1620 and ZF 16S 2320 TD version consist of:
- a central box containing the primary shaft, drive input shaft,
secondary shaft and the cogs of the four forward and one
reverse gear;
- a rear casing containing the Epicyclical Reducer Group
(G.R.E). The function of this is to double the number of
forward gears by means of epicyclical gears with helical
teeth.
This gives a range of gears that starting with four input
ratios permits eight different output ratios (four normal
ratio and four low ratio gears);
- a front casing containing the "splitter", that gives a further
double selection for each of the eight forward gears and
for the reverse gear.
The "splitter" halves the difference between two
successive gears, effectively splitting each gear into a slow
ratio (L = slow ratio) and a fast ratio (S = fast ratio).
These gearboxes therefore have a total of sixteen forward
gears with finely scaled ratios, all engageable in succession, and
two reverse gears.
The synchronisers are single cone type.
Figure 1
1. Distributor – 2. Servoshift – 3. Servoclutch – 4. *Servoshift power electrovalve
*
only for vehicles with F3B engine
SECTION 6
Lubrication is by means of a gear pump.
The double H type gear shift control is equipped with a
pneumatically powered "servoshift" device to improve gear
selection and engagement.
The servoshift is a device consisting of a mechanical/pneumatic
functional unit and a dual action cylinder.
The advantages of this device are:
- gear selection and engagement more rapid and with less
effort;
- it dampens the vibration of the control linkages, reducing
noise;
- less strain to the synchronisers.
The device functions mechanically in case of pneumatic system
failure.
The gearboxes mounted of vehicles with F3B engines are fitted
with a synchro protection device.
This permits pneumatic power to the servoshift for gear
engagement only after the clutch pedal has completed 70% of
the disengagement stroke.
It consists of an electrovalve controlled by a proximity switch
mounted on the clutch disengage master cylinder.
MANUAL GEARBOX
3
99356