close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2105843

код для вставки
Jan. 18, 1938.
c. |, PRESTQN Elf/M_
CONTROLLABLE FITCH PROPELLER
FiledlNov. 29, 1935
2,105,843
2,105,843
Patented Jan. 18, 1938
UNITED _STATE-s PATENT-,OFFICE ~
ì CONTROLLABLE FITCH PROPELLER
` Charles I. Preston and *HarryA Melville
_ Williamspo rt, Pa., assignors to Aviation‘Manu- y
"facturing Corporation, Chicago; IlL, a. corpora
tion of Delaware
Application November zo, 1935, serial No.> y,52,151 .
s calma ‘ (ci. 17o-163)"
The invention relates to hydraulic mechanism
for controllable pitch propellers.
In aircraft, it is now'common practice tovuse
lubricating-oil from the internal combustion en
5 gine which drives the propeller to operate hy
draulic means for changing the pitch of the
propeller-blades. Heretofore, it has been cus
tomary to freely pump lubricating-oil from the
engine to the hydraulic means. This frequently,
10 in the event of a substantial leak or breakage
in the pitch-change mechanism, resulted in re
ducing the pressure and volume of oil in the
lubrication-system of the engine and, in some
instances, below that required for proper lubri
15 cation suilieiently to cause engine failure or
damage.
_
The object of the invention is to provide im
proved. hydraulic mechanism for controllable
pitch propeller-blades, in which oil from the
20 engine, which drives the propeller, is used for
operating said mechanism, and in which provi
sion is made for limiting the volume of lubricat
ing-oil which can be taken from the engine for
the operation of the pitch-Varying mechanism.
25 By providing in the line for the oil from the
engine to the hydraulic mechanism a limited rate
of flow the engine, notwithstanding any breakage
of, or substantial loss in, oil in the hydraulic
mechanism, will not interfere with the lubrica
30 tion of the engine. The maximum rate of iiow
of the oil to said mechanism is limited so that
lubricating-oil pressure in the'engine will never
be reduced to such an extent as to interfere with
the efficient lubrication of the engine or to cause
35 failure from lack of lubrication. The maximum
rate of iiow may be so low that the amount of
oil normally added to the engine will compensate
for that used in the hydraulic mechanismk even
if loss of the oil should be permitted by the
40 latter.
’
This object is‘attained primarily by providing
lated volume in said chamber resulting from the
flow-restricting
, Other objects of
device.
the invention will appear from>
the detailed description.
l
The vinvention consistsin the several novel 5
features hereinafter set forth and more 'particu
larly defined by claims at the conclusion thereof.
_ In the drawing:
-
-Fig. 1 is a central longitudinal section'through
a portion of the internal combusion engine and l0
an aircraft propeller to which- the inventionis
applied. Fig. 2 is anenlarged section illustrat
ing the device for restricting the rate offlow- of
lubricating oil from'` the engine to ther accumu
lating .chamber from which oil is delivered to 15
the hydraulic mechanism.
Fig. 3 is a view of `
the devices connecting -the fluid pressure oper
ated piston and the propeller-blades for pitch
adjustment.
`
g
The invention is exemplified in a structure 20
comprising an internal combustion engine a, a
propeller shaft bfdriven fromv the crank-shaft c '
of the engine through suitable >reduction gear
ing d, a housing d5 which encloses the reduction
gearing and isadapted to retain lubricating-oil, 2’5'
a propeller hub e, in which propeller-blades f
are rotatably mounted for pitch variation and
hydraulic mechanism for shifting the bladesfor
pitch variation which comprises a fluid-cylinder
g fixedly mounted on the front end of the hub e, 30
a piston h in said cylinder, movable in one direc
tion by the lfluid under’pressure, links i pivotally
connected to the piston and connected, respec
tively, to arms k on the Shanks` of the propeller
blades, and springs r for retracting thepiston h 35'
when permitted by the reduction of fluidA pres
sure in the cylinder g. ' The reduction gearing d
comprises a gear` d1 which is connected to rotate
with the crank-shaft c, aninternally toothed
ring-gear d2 fixed to the propeller shaft b.and,40
intermediate pinions fd? whichlare journaled in.
a head d4 mounted,` between the engine-casing
between the pressure oil line and the hydraulic and the _housing d5 for the reduction-gearing. .
The housing d5 carries at its front end a bear
mechanism for adjusting thepitch of the pro
peller-blades, a restricting device or nozzle which ing b1 for the propeller shaft. The engine is 45
equipped with the usual pump (not shown) and
limits the rate of flow of the oil to said mecha
nlsm, so that the drop in volume at the maximum lines for circulating lubricating oil under pres
sure from a suitable Weller oil-sump, usually iny
flow will not interfere with the proper lubrica
the bottom of the crank-.case a”, to all the parts
tion of the engine and also by providing, be
of the engine and auxiliary equipment which 50l
50 tween the flow-restricting device and the hydrau
require lubrication, afs, well understood in the
lic pressure mechanism, an accumulating cham
ber of limited capacityso that the pump for art. The mechanism -thus far described may be
supplying the lubricant `to the fluid pressure of any Vsuitable type'> or construction known in'
`
"
.
`
mechanism may deliver suiiicient oil to operate theart.
Oil from the' engine is used for operating the" 55
55 said mechanism but no more than the accumu
2 .
2, 105,848 '
plstonh. to vary the pitch oi' the propeller blades
f. For this purpose the piston his provided with
a hollow stem h', which is slidable in the shaft
b and provided with a packing-ring hz at its
inner end to form a fluid-tight ilt between the
bore of the propeller shaft and the hollow stem
of the piston. A head I2 is ñxed in the shaft
age or leak, the amount of oil taken from the
oil supply in the engine will always be insuf
flcient to reduce the pressure suiliciently to in
terfere with the proper and normal lubrication
of the engine and its auxiliaries. 'I'he nozzle I’
is _in the form of a screw-plug which can be
b, inwardly of the piston-stem Il', and an oil-V threaded from below into the lower portion of
delivery pipe I3 having its ends ilxed in head I 2 n the bottom-wall of chamber 14, so that it can be
readily removed for cleaning purposes. This
10 and shaft b, is adapted to deliver oil from an an
plug is locked in place by a split-ring 1G.
nular channel in a ring I5, which is fixed to ro
»A pump m is provided for forcing oil under
tate with the propeller shaft b, and is provided
with piston-rings I8 to prevent escape of oil» pressure to the cylinder g for operating piston
through the bearing b' for the shaft. Oil forced h. `This pump is -driven by a vertical-shaft m'
which is -îournaled in a sleeve 1n2 which extends
15 to the oil-ring I5 passes through pipe I3, thepro
peller-shaft b in front of the` head I2. -and the vertically throughV the chamber I4. A ge'ar mi,
hollow stem h' oi' the piston h.to react on the which is integral with ring I5, is secured to ro
- outer end of the piston and operate the ylinks i
for rotating the propeller-blades f onk their own
20 axes to increase the pitch of the blades. In this
type of propeller, the increase of oil pressure in
the cylinder 'a operates the blade-shifting mech
anism to reduce the pitch and. “Don decrease oi'
pressure, the counter force serves to increase the
25 pitch of the blades. This exemplliles hydraulic
mechanism operable by oil under pressure for
shifting the propeller-blades to vary their pitch.
The lubricant lines comprise a pipe II for de
livering oil under pressure from theoil-pump for
30 the engineinto a passage l in the head d', from
which it llows to a forwardly leading „duct Vl' in
the housing d5 to a now-restricting device for
limiting the -rate of ilow‘from the pump to the
tegral with the housing d5 and is adapted to >contain a limited‘qu’antity of oil, such for'example
'An important attribute of the dow-restricting
Y
n', ring I5, pipe il and piston-stem h',y into
quantity '
which may accumulate inchamberl l* to flow back
it will’ñow back
y `
the propeller-shaft at a speed proportionate to
the propeller and engine Ispeed and draw oil
from the contents of chamber l* through intake
duct n and force it through the discharge duct 40
which this nozzle discharges the oil. This cham
40 ber is formed by a partition-wall l” in and in#
50 into the housing d5 from‘which
' into the oil well in the motor.
,
partment 14. The pump m'will be driven from
the engine to any accumulating chamber l‘, into
cant for the reducing gearing. y Overilow and vent
pipes l7 are -. provided lto permit `the excess oil
`
A speed-controlled governor s, preferably of
the ily-ball type, as well understood in the art,
is driven by the pump-’shaft m’ to operate a
During the operation of the propeller-shaft,
the oil-pump of the engine will force oil through
pipe I0, duct l', and nozzle l2 into the oilcom
the housing d5 and has a 'smail'or restricted ‘ori
for'the operation of the hydraulic'mechanism.
to the cylinder g.
pressure regulating valve t, which permits some
iice l3 which limits the'rate of ñow of oil from
. This partition separates the chamber l* from the
y: chamber in the housing which contains the lubri
m’ 4to drive the pump‘m. - A duct n leads from
oil-chamber I4 to the intake of the pump. A duct 20
n' leads from the discharge side of the pump to
ring I5. From ring I5, the oil is forced through
pipe I3, propeller-shaft b and piston-stem h'
of the oil from the rhydraulic cylinder a to ilow
into the oil compartment I4. A cable t' is usually 30
connected to th’e governor, so that the regulating
valve t may also be manually controlled.
~ . hydraulic pitch-controlling mechanism. This de
35 vice consists of a nozzle 12,'which is screwed into
as a quart, or approximately a sumcient
tate with the 4propeller-shaft and drives a bev
elled gear ma ñxed to the upper end of shaft
the outer end of they cylinder a. 'I’he pressure of
the voil will be governed by the valve t under
control oi' the speed-controlled governor s. and
the manual control cable t'_to control the pres~
sure inthe cylinder a _and the corresponding
pitch-changes effected by the movement of the
piston h in said cylinder.
l
The oil >delivered* to chamber I4, from which
the pump m takes its supply. enters said chamber
through ducts l. l1 and nozzle l“, which islpro
vided with the restricted oriilce l“, to limit the
nozzle l2r and the chamber l* for retaining a lim
ited'supply of oil for use in the hydraulic mech _ rate of ilow’irom theoil sump or well a" of the
p
anism, is .that the'maximum rate of flow of oil - engine to the chamber 1‘. As a result,
the volume
from the oil-pump for the engine is- reduced. to ï `„of oil taken from the oil-well or sump of the
engine for use in thehydraulic pitch-change
such an extent that the flow of oil to the cham»
ber 14 for use in the hydraulic mechanismpswill mechanism will belimitedto prevent substantial
_be insumcie'ntat all times to interfere witlî'the
dnormal pressure of oil required for lubrication of»
the engine'and the auxiliary parts. The chamber
I4 permits a limited quantity of oil to accumu
late from the flow-restricting nozzle for the
operation of the'hydraulio mechanism. <The ratev
65 of ilow into chamber I4 is far below the capacity
of pump m.. As a result. the pump cannot, at
any time, draw oil from the engine at a greater
reduction of pressure in the oiling system of the
engine.'
'
'
In practice, leaks ,or breakage occasionally
occur in the hydraulic mechanism and if the
booster-pump for forcing oil from the engine to
said mechanism continues‘to operate under such
conditions, the pressure of oil in the engine will'
be quickly reduced, which results in engine fail
ure or injury due to inadequate lubricant.
With the present invention, the vmaximum rate
of ñow of oil through the nozzle l2 to the' cham
ber -l4 for use in the hydraulic pitch-change
rate of flow than that permittedîby the nozzle lì
Should -the chamber l4 be drained by the pump,
70
no additional oil can'be'delivered toy the cylinder
U, by pump m ‘except the small quantityperml't ' mechanism, is so low that it is impossible to bleed
ted to enter said chamber through nozzle l’. The the 'oil supply in the engine. As a'result, it
maximum rate‘of ilow through Vthis nozzle is so becomes impossible to kdeplete the supply ofoil
in the lubricating system of the engine> by the
.75 low thatin the event of theloss of the oil from
the' hydraulic` mechanism, on’account of break
hydraulic pitch-change mechanism.
'
The invention exemplifies hydraulic pitch
60
,3
2,105,843
change mechanism for\ propellers in which oil
under pressure for operating said mechanism is
derived from the supply of lubricating-oil for
engine, means for accumulating a sufficient quan
tity of oil from the now-restricting device to
operate `the pitch-change means, and controllable
means for delivering Voil from the accumulating
device lto the hydraulic pitch-changing means.
5. The combinationwith a variable pitch pro
peller, provided with hydraulic means for vary
the engine and in which the rate of flow of the
oil from the engine is restricted to prevent re
duction of pressure of lubricating-oil in the en
gine or from reducing it sufficiently to cause
insuñ‘icient or ineflicient lubrication of the engine ' ing the pitch of the propeller blades, of a hous
and its associated parts.
10
'
The invention is not to be understood as re
stricted to the details set forth, since these may
be modified within the scope of the appended
claims, without departing from the spirit and
scope of the invention.
Having thus described the invention, what we
claim as new and desire to secure by Letters
Patent is:
1. 'I'he combination with a variable pitch pro
peller provided with hydraulic means for varying
20 the pitch of the propeller blades, of meansfor
delivering lubricating oil under pressure from
the engine-lubricating system, comprising a con
stantly open device for restraining the rate of
flow of oil from the engine suiiiciently to pre
ing‘through which the shaft of the propeller exi'
tends, a chamber in the housing for accumulat 10
ing a suñlcient quantity of oil to operate the
pitch-changing meansîmeans for delivering oil -
under pressure from the engine-lubricating sys
tem Jto the chamber, comprising a constantly
open device for restricting the rate yof ilow of oil 15
from the engine suiilciently to prevent substan
tial reduction of the oil pressure in the lubricat
ing system to less than that required for` .proper
lubrication of the engine, and> controllable means
for delivering oil from the accumulating chamber
to the hydraulic pitch-'changing means.
6. The combination with a variable pitch pro
peller, provided with hydraulic means for varying
the pitch of,V the propeller blades, of a housing
25 vent substantial reduction of the oil pressure . through which the shaft of the propeller extends,
Aa chamber in the housing for accumulating a
in the lubricating system to less than that re
suihcient quantity.of oil to operate the pitch
quired for proper lubrication of the engine,
change means, means for delivering oil under
pressure from the engine-lubricating system to
the chamber, comprising a plug in, and remov 30
the pitch-change means, and means for deliv- , able from the outside of, the housing, having a
ering oil from the accumulating means to theV constantly open oriñce for restricting the rate
hydraulic pitch-changing means.
oi’ tlow or oil from the engine sufiiciently to pre
-' 2. The combination with a variable pitch pro
vent substantial redúction of the oil pressure in
peller provided with hydraulic means for vary
35 ing the pitch of the propeller blades, of means the lubricating system to less than that required
for proper lubrication ot the engine, and con
for delivering lubricating oil under pressure from trollable means for delivering oil from the ac
the engine-lubricating system, comprising a con
cumulating chamber to the hydraulic pitch
means for accumulating a sufiicient quantity of
oil from the now-restricting device to operate
stantly open nozzle with an oriñce for restrict
ing the rate of ñow of oil from the engine sufñ
ciently to prevent substantial reduction of the
oil pressure in the lubricating system to less
, than that _required for proper lubrication of the
engine, means for accumulating a suiìcient quan
i ~ tity of oil from the flow-restricting device to
45 operate the pitch-change device, and controllable
means for delivering oil from the accumulating
means to the hydraulic pitch-changing means.
3. The combination with a variable pitch pro
peller provided with hydraulic vmeans for varying
50 the pitch ofthe propeller blades, of means for
delivering lubricating oil under pressure from
the engine-lubricating system, comprising a con
stantly open device for restricting the rate of
flow of oil from the engine sui'ilclently to prevent
55
substantial reduction of the oil pressure in the
lubricating system to less than that required for
proper lubrication of the engine, means fo'r ac
cumulating a suiiicient quantity of oil from the
60 flow-restricting device lto operate the pitch-`
change means, a pumpdriven from the propeller
for forcing oil from the accumulating means to
the hydraulic pitch-changing means, and means
for controlling the'delivery of oil to the pitch
f.
`
65 changing means to shift the blades.
4. The combination with a. variable pitch -pro
peller provided with hydraulic -means'iîor varying
changing means.
_
`
'7. The combination with a variable pitch pro
peller, provided with hydraulic means for varying
the pitch of the propeller blades, of a housing
through which the shaft of the propeller extends,
a chamber in the housing for accumulating a
suiiicient quantity of oil to operate the pitch
change means, means for delivering oil under
pressure from the engine-lubricating system to
the chamber, comprising a duct in the housing
and a removable ~plug inthe housing, having a
constantly open oriñce for restricting the rateo! flow of oil from the engine sufficiently to pre
vent substantial reduction of the oil pressure in
the lubricating system to- less than `that re
quired for proper lubrication of the engine, and
controllable means for delivering oil from the
accumulating chamber to the hydraulic pitch
changing means.
_
8. 'I'he combination with a variable pitch pro
peller, provided with hydraulic means for varying
the pitch of the propeller blades, ofv a housing
through which the shaft of the propeller extends,
a chamber _in the housing for accumulating ya suf
ficient quantity of oil to operatethe pitch-change
means, means for delivering oil under pressure
from the engine-lubricating system, comprising ar
constantly open device for restricting the rate of ,
ilow of oil from the engine sufficiently to prevent ‘ .i
the pitch of the propeller blades, of means for'de-` substantial reduction of the oil pressure in the - _
livering lubricating oil under pressure from the lubricating system to less than that required for proper lubrication of-the engine, a pump driven
70 engine-lubricating system, comprising a remov
from the propeller shaft `and connected to the
able plug having a constantly open .oriñce for re
stricting the rate of iiow of oil from the engine housing for delivering oil from the accumulating
sufiiciently to prevent substantial reduction of chamber to the hydraulic pitch-changing means.
CHARLES I. PRESTON.
the oil pressure in the lubricating system to less
. H. MELVILLE HAMMILL.
75 than that required for proper lubrication of thev
Документ
Категория
Без категории
Просмотров
0
Размер файла
618 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа