WSM. 124
Section E (Gearbox & Overdrive)
2nd
re-issue
Page 13
OVERDRIVE
The Laycock-de Normanvllle Overdrive unit
gives
an increase in propeller shaft speed of 24·67%, that
is, It has a ratio of 0·802 : 1.
WORKING PRINCIPLES
At the top of Fig. 7, the unit is shown diagram
matically In direct drive. The cone clutch, which is
fixed to an extension of the sunwheel, is held to
the rear by spring pressure so that the Inner
friction band contacts the outside of the annulus.
This locks the gear train, and the drive Is trans
mitted directly through the uni-directional clutch.
Any over-run or reverse torque is taken by the
cone clutch.
Fl1. 7. Diagrammatic
sections
The lower illustration In Fig. 7 shows the unit in
overdrive. The cone clutch Is held forward by
hydraulic pressure so that the outer friction band
of the clutch is locked to the stationary brake ring.
As the cone clutch is splined to the sunwheel, the
sunwheel Is also held stationary. The planet
carrier is splined to the Input shaft, and Is driven by
it. The planet wheels are thus driven round the
stationary sunwheel, and in so doing rotate the
annulus and tall shaft at a speed greater than that
of the Input shaft.
THE HYDRAULIC SYSTEM (See Fig. 7)
A cam, keyed to the gearbox mainshaft, operates
the plunger of a pump, which forces oil via its
discharge valve, into the relief valve. The line
pressure Is kept constant by introducing a relief
valve Into the system.
From the pump, oll under pressure is passed to
the operating cylinders via the operating valve
0
TO
rf
SUMP
·-�-
OP£JIA11NG
�
LFIER
Fl1, 8. Operating valve
Summary of Contents for ALPINE I SERIES: APLINE II SERIES
Page 1: ......
Page 189: ...Fis 21 Ball pin heirht checkinr fixture in position Details of items 1 to 4 In Fig 22...
Page 208: ...Fla 3 Exploded view of rear axle Hypoid Bevel Drive...
Page 220: ...Page 16 WSM 12 f Section G Rear Axle 0 QQ I I I I I t 0 ii 8 ts t 0 Cl 2 i J...
Page 247: ...Page6 WSM 124 Section J Steering N Iii it...
Page 299: ...Page 40 3 6 7 8 Fis 22 Se rvo unit exploded view Sect WSM 124 ion K Brakes 18 419 GZo 21...
Page 413: ..._ PRINTED IN ENGLAND 9Y WREN PRINTING CQ LTD LONDON...