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SEPTEMBER 2OTH,

I945

ROLLS-ROYCE

CRIFFON

FLIGHT

(65)

MAIN BEARING

CRANKSHAFT

OIL STAND PIPE

BALANCE WIEGHT

1*3

partly relieved from crankshaft rotational variations and totally relieved from end-float effects.

Going to the other end of the shaft, we encounter the beautifully neat torsional spring-drive coupling, the pur- pose of which is to relieve the crankshaft from impeller

inertia.

When

wheel ''

inertia

be

accelerated

pistons,

and

the

the throttle is opened of the impellers does as quickly as is the resulting lag engenders

quickly the "fly- not allow them to crankshaft by the a tendency to twist

the the but

crankshaft.

Again, when the throttle is rapidly closed

impellers try to similar twisting

overrun the crankshaft, with reversed effect. To relieve the shaft from these

embarrassments a spring drive is and impellers, which absorbs the

embodied between shaft initial shock loading re-

sulting which, shown

from the inertia. The coaxial shaft and sleeve splined together, form the springing member, are in a detail drawing.

STOP PLATE LIMITING TORSIONAL MOVEMENT

SPRING DRIVE GEAR

There is not such a number

the Griffon as is found

in

the

of gears at Merlin, the

the rear end of front-end cam-

T h r e e - q u a r t e r r e a r d e t a i l o f t o r s i o n s p r i n g d r i v e c o u p l i n g a t . r e a r e n d o f c r a n k s h a f t .

drive

arrangements,

^etc,

being

the

cause;

nevertheless, there is still a goodly number of wheels, bearings and shafts at the back of the Griffon, and to at- tempt to describe these individually would, as well as being tedious,

serve no

worthwhile

function.

They can

almost all be traced in the Max Millar drawing and other details ; how- ever, it is worthy of emphasis that the nest- ing of this mass of drives is as compact and neat as the highest order of mechanical de- sign ingenuity can make it.

In the title sub-head- ing of this article are

the words

'' Classic

Orthodoxy of

Design,"

Underside view of triple-entry throttle with metering Venturis and injector carburettor.

fc* --' *s

which clusion.

is

carried to It is for

the absolute of logical this reason, almost

con- un-

i f w doubtedly, that the Griffon carries further the

  • -

    ""standard

set

by,the Merlin as being the high-

est performance engine in exist- ence, for other engines of similar power are larger or, if of the same size, are lower powered. Such a feature, when coupled to

great reliability,

cannot well be

achieved

by

'' mushroom

methods—it of lineage

comes only by way

of

thoroughbreds

born of painstaking unrivalled experience.

care and It is on

this foundation that Rolls-Royce rests so

the name securely.

The main body of the Griffon is not unlike the later Merlins in that it has a light-alloy pentagonal-section crank-case, the lower half of which is a dry sump housing the oil pressure and scavenge pumps with their niters in a well at the rear end.

and in the

Griffon

probably

more

than

in

any

other

Rolls

engine engine

is this which

trait manifest.

There

is

awfully

cunning

or

is nothing about the

''

super

new."

It

is

the

epitome

pf

plain,

straightforward

simplicity

of

design,

REDUCTION GEAR P'NION COVER

SEMI-FLOATING DRIVE -ANULUS

CRANKSHAFT OIL PEED DE-AERATEh

A baffle plate is also embodied in the lower half case to restrict oil surge and prevent excessive breathing under negative G accelerations. Cylinders are floating wet liners fitted in light alloy jacketing blocks, the compressive stress due to the holding-down studs being taken by the jacket. The liners are chromium plated in the bores for about 2^ inches down from the head as an anti-war measure, it being in this area that maximum wear from corrosion and great

temperatures occurs. head of the liner, and,

A flange is incorporated round the with aluminium sealing rings above

and ing the

below, is nipped between the cylinder head and jacket-

block. liner

Thus all thermal expansion takes place relative to the

and contraction lower end.

of

This fashion of nipping the liners at the top means that, when tightened down, there is a gap of 0.15 in. between adjacent faces of the cylinder-head block and the jacketing block which, until one knows the reason, looks very queer. To prevent excessive cantilever loading on the joints adjacent to the end studs when at normal running tem- peratures, flat steel plates are interposed at each end of the cylinder bank between head and jacket, these plates transmitting the load as the engine warms up.

rDA,

CRANKSHAFT OIL SUPPLY TUBE

I I

AIR BLEED HOLE

SUPPLY

GIVING COUPLING

.

DUCT

Three-quarter front view of semi-floating coupling between crankshaft and reduction gear.

Combustion chambers are machined all over and are quite orthodox in shape. Valve seats are shrunk-in inserts and the porting passages are scurfed—very smoothly indeed on the inlet side (as is to be expected), but fairly roughly on the exhaust side. The valves have Brightray seat fac- ings and, whilst the inlet valves have extended guides, the

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