Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to variable speed transmission devices
and more particularly to a transmission device which is infinitely variable over
a predetermined range. This application is a division of copending application
Serial No. 292,669, filed December 8th, 1977.
The present infinitely variable transmission permits variation in
speeds betweell the power input shaft to the transmission and the power output
shaft, as well as tor4ue multiplying and positive drive mechanical power trans-
mission over an extremely broad range of speeds in either forward or reverse
directions, from zero to several ~imes the input speed. The output torque with
the transmission is inversely proportional to the output speed with high
efficiency throughout its entire range. And, in the transmission of the present
construction, there is no apparent torque or power limit too large for the
transmission to effectively handle.
Although infinitely variable transmissions have been previously pro-
posed, such transmissions are relatively complex and require a large number of
moving parts, such as shown for example in United States Patent Nos. 3,803,931
and 3,229,549. By the construction described herein an infinitely variable
transmission is provided which is smaller in size and formed of fewer and simpler
parts as compared to previously proposed transmissions of this type. Moreover,
the transmission is economical to manufacture and should be far easier to main-
tain than conventional transmissions it is intended to replace. It is believed
that the use of this transmission in an automobile could double the automobile's
mileage by allowing the automobile engine to operate at its more efficient fuel
effective low speed high torque mode more often, regardless of vehicle speed.
It also makes the single shaft Brayton engine practical. In addition, the
variable throw feature of the present invention can be used in other types of
transmissions apart from auto transmissions of the type with which applicant is
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principally concerned herein and the novel clutch used in the transmission o
the present invention is an important element by itself, and can be used apart
from the transmission disclosed herein. In particular, this clutch element can
serve as a slip clutch, indexing, overrunning, or centrifugal clutch in many
applications. The clutch element does not rely on mechanical parts slipping
against one another or jamming as in a sprag clutch, and therefore will be more
durable in use.
The present invention accordingly provides a variable throw crank
assembly for use in oscillating a drive control element about a fixed point with
a variable eccentricity comprising a first hollow shaft, a control shaft
rotatably mounted in said hollow shaft, a first crank secured to the control
shaft in eccentric parallel relation, a ring gear mounted on said hollow shaft
surrounding said first crank; a pinion gear rotatably mounted on said first
crank in meshing engagement with said ring gear; a second crank secured to
said pinion gear in eccentric parallel relation to the first crank and defining
a crank pin having at least one position aligned with the axis of the control
shaft, and means for selectively rotating said control shaft within said hollow
shaft whereby movement of said pinion with respect to the ring gear causes the
pinion gear to rotate, thereby to vary the eccentricity of said crank pin with
respect to the axis of said hollow shaft.
The above, and other objects, features and advantages of this invention
will be apparent in the following detailed description of an illustrative embodi-
ment thereof, which is to be read in connection with the accompanying drawings,
wherein:
Figure 1 is a schematic illustration of one embodiment of the
transmission;
Figure la is a schematic view of the control means used for varying
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the throw of the crank in the device of Figure l;
Figure 2 is a schematic perspective view illustrating the operation
of the variable throw clutch;
Figure 3 is a schematic end view illustrating the oper2tion of the
varlable throw clutch;
Figure 4 is an end view similar to Figure 3 showing the oscillation
of one of the clutches used in the transmission;
Figure 5 is a sectional view of a transmission constructed in
accordance with the broad principles of the present invention;
Figure 5a is a sectional view taken along line 5a-5a in Figure 5;
Figure 6 is an end view taken along line 6-~ of Figure 5;
Figure 7 is an end view taken along line 7-7 of Figure 5;
Figures 8, 9 and 10 are sectional views taken along the corresponding-
ly numbered lines in Figure 5;
Figure 11 is an enlarged side longitudinal sectional view of one
embodiment of a clutch adapted to be used in the transm-ssion;
Figure 12 is a sectional view taken along line 12-12 of Figure 11;
Figure 13 is a longitudinal sectional view of a variable throw crank,
Figure 13a is an end view, on a reduced scale, taken along line 13a-
13a of Figure 13; and
Figure 14 is a sectional view taken along line 14-14 of Figure 13.
For the sake of a full understanding of the invention, it is described
in the environment of the invention separately claimed in the parent application
Serial No. 292,669.
Referring now to the drawings in detail and initially to Figure 1
thereof, an infinitely variable transmission 10 is drivingly connected to a
power source 12, e.g. internal combustion engine, having an output drive shaft
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14. The transmission is schematically illustrated in Figure 1, for easier under-
standing of the invention, and is illustrated in greater detail in su'~sequent
views of the drawings. Essentially the transmission includes a fixed housing
16 into which the output shaft 14 of the engine 12 extends. The engine shaft
includes an output gear 18 drivingly engaged with a pinion gear 20 secured to
a hollow shaft 22 in the transmission. This shaft is rotatably mounted in
housing 16, as described hereinafter, and has a separate sub-housing 24
rotatably mounted thereon. The end 26 of shaft 22 is rigidly secured to a
ring gear 28 having internal radially extending teeth.
A control shaft 30 is rotatably mounted within hollow shaft 22 for
relative rotation with respect to the hollow shaft. However, a gear assembly
32 is provided which interengages the shafts 22, 30 so that they normally will
rotate together when power is supplied from engine 12. Gear assembly 32, as
described hereinafter, also will permit the operator of the transmission to
selectively rotate shaft 30 within shaft 22 in order to vary the eccentrlcity
of the variable throw crank of the transmission. This crank is connected to
shaft 30, within ring gear 28.
The variable throw crank includes a first crank member 34 eccentri-
cally mounted on the end of control sha-ft 30 and it has a pinion gear 36
rotatably mounted thereon. A second crank 38 is secured to gear 36 for
rotation therewith. As illustrated in Figure 1, crank 38 includes a crank
pin 40 which is located, at least in one position, to be in axial alignment
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with the axis of rotation of shaft 22. By rotating shaf~ 30 with respect
to shaft 22 the centeT of the pinion gear 36 is displaced r~lati~e to ring
gear 28, causing gear 36 to rotate relative to gear 28, so tnat crank pin
40 of crank 38 rotates therewith. This varies the eccentricity of tne
crank pin with respect to the axis of rotation of shaft ~2, as shown
sche~atically in Figure 2.
When crank pin 40 is aligned with the axis of rotation of shaft 22,
joint rotation of shafts 22, 30 will simply cause crank pin 40 to rotate
about its central axis, which coincides with the central axis of the shaft
22. However, when the crank pin is moved to an eccentric position with re-
spect to the axis of rotation of shafts 22, 30 it will rotate in a circular
path about that axis of rotation. Rotation of the crank pin in this mode is
used to operate a series of clutches to transfer power to the output shaft 42
of the transmission, which shaft is fi~ed to the sub-housing 24.
A control plate or master link 44 is rotatably mounted on crank
pin 40. The mas*eT link's angular orientatisn is held relatively fixed with
respect to the interior sub-housing 24 through a gear assembly 46 which in-
cludes an end gear 48 fixed to housing 24. Thus, while plate 44 will move
with crank pin 40, as the crank pin rotates therein, it is held against rota-
tion relative to housing 24 on the crank pin.
A plurality of pitman ar~s or links 50 are pivotally connected attheir opposite ends to ~aster link 44 and to cTanks 52 rigidly secured to in-
put shafts 54 of clutches 55. These clutches are constructed, as descrihed
hereinafter, such that upon oscillation of their input shafts relative to
their output ends, in a first direction, an output ~ear 58 associated there-
with is rotated. The gears are no~ rotated by the clutch input shafts when the
cranks of the clutches are returned in an opposite direction to ~heir original
position. The clutches are out of phase with one another, so that as the
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master link 44 moves with crank pin 40, the clutches sequentially drive
their output gears 58 It is noted that plate 44 is termed a master link
because for each separate pitman 50 it acts as a separate link connected to
the eccentrically moving crank pin to oscillate the pitman. Since the plate
is connected to all the pitmans it controls them all, simultaneously and
thus is a master link.
Gears 58 are mcshingly engaged with a central gear 60 ~Yhich is
fixed in any convenient manner within fixed housing 16. As a result, gear
G0 will not rotate upon application of the drive from gears 58. Instead,
the reaction of gears 58 against gear 60 will cause sub-housing 24 to ro-
tate, carrying the clutches therewith. Thus, the clutches and master link
44 rotate about the axis of rotation of shaft 22, but the master link 44,
while moving about the axis 22 does not rotate relative to housing 24 on
its crank pin 40 so that the master link's relative position with respect to
the clutches remalns constant. In this form of the invention the trans-
mission is reverted with the output drive of the clutches applied to a
stator gear which then causes the housing in which the clutches are mounted
to rotate. However, it is contemplated that the transmission be non-re-
verted, with gears 58 drivingly engaged with a rotatably mounted output
gear rather than a stator gear and with housing 24 fixed in housing 10.
Thus the gears 58 will drive the output gear rather than cause housing 24 to
rotate. However, with a reverted gear train it has been found that overdrive
transmission ratios can be provided between the input and output shafts and
clutch torques in the transmission will be much less than in the non-reverted
form o$ the transmlssion.
With the transmission as thus described, by simply varying the
throw or eccentricity of crank pin 40 with respect to th~ axis of rotation
of drive shaft 22 the amount of oscillation imparted to the input cranks of
T~ 6 r
the clutches can be varied, thereby to vary the speed -ratio between input
shaft 14 and the output shaft 42. This is more clearly illustrated in
Figure 2 of the drawing, wherein it is seen that crank pin 40 (sho~m in
solid lines) is located in longitudlnal alignment with the axis of rotation
of shaft 22. In that position ~hen shaft 22 is rotated, shaft 30 rotates
thercwith and crank pin 40 simply rotates ~ithin master link 44 and imparts
no movement to the master link. ~-lowever, when the eccentricity of crank 40
is varied from lts zero position to some other position the master link 44
will be moved in a generally circular path of travel as indicated by the
phantom llne 60 in Figure 4 with the center of rotation of this path of
travel being the axis of shaft 22. Because the master link rotates with the
clutch mounting during ro~ation of the clutch mounting of sub-housing 24, and
because it is held against rotation relative to sub-housing 2~, on its cen-
tral axis by the gear assembly 46, movement of the master link about axis 22
will cause links 50 to oscillatc cranks 52 of clutches 56 in order ~o
selectively drive to the clutches during one direction of movement of cranks
52, As mentioned, these clutches are out of phase with one another so tha* a
step~ise drive is imparted tojsub-housing 24 and thus to output shaft 42.
~owever, because there are a series of clutches a slight ripple effect may
be produced by the stepwise drive which will be substantially unnoticed and
absorbed by the hysterisis effect of the assembly. In addition, to overcome
; this ripple effect, particularly in the reverted type of transmission input
gears 18, 20 may be lobed to put a ripple drive into the transmission to
eliminate the ripple output.
Referring to the more detailed illustration of the invention shown
in Pigure 5 of the drawings, input shaft 14 of engine 12 is journalled in
housing 16, in any convenient manner. As seen in Figure 6, shaft 14 has the
output gear 18 secured thereto by a key 62 or the like, with that gear being
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in meshing engagement with gear 20 on shaft 22. These gears have a lobed
configuration, which places a ripple input into the drive to shaft 30 which
counteracts and even entirely removes the ripple effect produced by the
crank~action. Ilowever, these gears may be circular in the non-reverted con-
figuration of the transmission since the ripple effect produced by the
clutches is then s-lbstantially completely absorbed by the hysterisis effect
of t~e transmission.
Shaf-t 22 is rotatably mounted in housing 16 by bearings 64 or the
like, with sub=housing 24 being rotatably mounted thereon by bearings 66.
The left end of shaft 22 has a control gear 68 keyed thereto, while the right
end of the shaft has the ring gear 28 mounted thereon. Crank control shaft
30 is rotatably mounted within shaft 22 by a bearing 70 and extends through
the shaft to its left end 72 on which a control spur gear 74 is secured.
The extreme end 72 of shaft 30 is recessed to receive an end bearing 76
which aids in supporting the assembly of the transmission within housing 16.
The right end of control shaft 30 has an integral crank formed
thereon includlng an eccentric crank pin 34 which is located to be parallel
to and offset from the axis of rotation of shafts 22, 30. This crank pin
and the mass journalled thereon are balanced by an opposed counterweight 78
and it has a spur gear 36 rotatably mounted thereon in meshing engagement
with the inner row of teeth 28a of ring gear 28. Crank 38 is rigidly se-
cured at its inner end to gear 36 for rotation therewith and forms the
crank pin 40 which is located so that, in one position of gear 36, the pin
is in alignment with the axis of rotation of shafts 22, 30.
The master link 44 is rotatably mounted on crank pin 40 by a
bearing 82 and has an integral constraint gear 84 formed therewith. A
counterbalance arm 86 is also journalled on crank 40.
The pitman or connecting links 50 are pivotally connected in a
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generally circular array around ~aster link 44 at their inneT ends. l`he outer
ends 88 of these links are pinned (i.e. pivotally connected) to cranks 52 of
clutches 56. These cran~s are keyed to the clutch shafts 90 which are
journalled in sub-housing 24 by bearings 92. As mentioned, sub-housing 24 is
rotatably mounted on shaft 22, within fixed housing 16, and has the output
shaft 42 of the transmission rigidly secured thereto for rotation with the sub-
housing.
Clutches 56 each include clutch housing sections 94 which are
bolted together by bolts 95 about a housing ring 96 which defines an internal
chamber 98 between the housing sections 94. The clutch shaft 90 extends
through this chamber and is rotatably received within housing sections 94 by
bearings 100. A rotor 102 (see Figure 5a) is splined to shaft 90 for ro-
tation therewith. This rotor has a plurality of radially extending slots
104 formed therein ~hich receive radially extending vanes 106. The vanes may
be biased upwardly by springs 108 so that the free ends 110 of the vanes are
urged by the springs towards the peripheral wall 112 of ~ing 98. Two dia-
metrically opposed arcuate ports 114 are formed in one of the housing
sections 94 adjacent the path of travel of the periphery of rotor 98. These
ports feed passages 116 which connects them to an annular pressure ring 118
located in communication with the lower ends 120 of slots 104. As described
hereinafter when shaft 90 and rotor 102 are rotated in a first direction,
relative to ring 98, hydraulic pressure is built up in the spaces between
vanes 106 adjacent ports 114 and causes housing 94 to be wedged with and to
rotate with shaft 90. But when shaft 90 is rotated in an opposite direction,
that pressure is relieved and the housing sections 94 are undriven.
The left hand housing section 94 of each of the clutches (in the
illustrstive embodimen~ of the invention six clutches are arrayed around the
sub-housing 24 but more or less than six clutches can be used) have clutch
gears 58 secured thereto. These gears are posi~ioned in ~eshing 0ngagement
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with fixed gear 60~ That gear is secured by bolts 124 to fixed housing 16.
Constraint gear 48 is fixed to sub-housing 24 in any convenient
manner for rotation with the sub-housing about the axis of rotation of the
shafts 22, 30. As seen in Figure 10, constraint gear 48 is in meshing
engagement Wit]l an idler gear 130 whicll, in turn, is in meshing engagement
with a transfer or compound gear 132. That gear includes an integral com-
panion gear 134 which, as seen in Figure 9, is in meshing engagement with an
idler gear 136. The latter is then engaged with the constraint gear 84 se-
cured to control plate 44. The gears 132, 134 are rotatably mounted in the
counterweight constraint link 86 by a b~earing 139; and an additional counter-
weight constraint link 140 is journalled on link 86 at bearing 139, as
illustrated in Figure 5, and is also journalled within constraint gear 48 by
a bearing 142. This link carries the idler gear 132, while constraint link
86 carries idler gear 136. These gears all cooperate to insure that the
master link 44 is held against rotation Oll crank arm 40 relative to sub-
housing 24,
In the embodiment of the invention illustrated in Figures 5 and 7,
the eccentricity of crank pin 40 is varied with respect to the axis of ro-
tation of sha$ts 22, 30 by ~he gear assembly 32 which is located within a
control housing 150 secured to housing 16, This gear assembly 32 includes an
idler gear 152 rotatably mounted on a control shaft 154 for relative rotation
wlth respect to that shaft. The control shaft is rotated to rotate shaft 22
relative to shaft 30 in any convenient manner, e.g. by a crank end 155
secured thereto.
A pa.lr of links 156 are secured or keyed to shaft 154 at one end
and to a shaft 158 at thelr opposite ends. A compound gear consisting of
gears 160, 162 is journalled on shaft 158, wi~h gear 160 meshing with idler
gear 15~ and gear 162 meshing with an ldler gear 164 also journalled on shaft
r~ 10 r~
154. The gears 152, 164 are respectively engaged ~ith the gears 74, 68 on
shafts 30 and 22.
When crank 155 ~and thus shaft 154) is held in a given position ~as
for example by a hydraulic control, or manually) and shaft 22 is driven from
input shaft 14 of the engine, shaft 30 turns at the same speed and the throw
of crank pin ~0 remains unchanged, because the ring gear and crank shaft 30
turn together as one. Ilowever, if crank 155 is rotated, this rotates links
156 causing gear 74 (which is meshed with gear 152) to turn relative to gear
68 which is in meshing engagement with gear 164. As a result, shaft 30 turns
relative to shaft 22 and ring gear 28 so that gear 36, which is in meshing
engagement with the ring gear and journalled on crank 34, turns causing crank
pin 40 to move relative to the center line of the main shaft, thereby varying
the thro~ of the crank.
Movement of crank 155 may be controlled by a hydraulic double act-
lng cylinder or the like 161 having its piston rod 163 ~see Figure la)
connected thereto. Fluid supply to the chambers of the cylinder can be con-
trolled in any conventional manner to cause the piston rod to move crank 155
to any desired position and to hold it in the selected position. And, the
force thenjnecessary to control crank 155 is very small depending on part
only of the input and independent of the output torque of the transmission
itself.
In the operation of the invention shown in Figures l and 5, when
the crank pin is in its zero throw position and the engine or motor 12 turns
shaft 14, ring gear shaft Z2 is rotated by the cooperation of the lobed gears
18, 20, and made to turn at the same average speed in the opposite direction
with a ripple motion. The control gear 68, driving through gears 164, 163,
160~15~, 74~ turns shaft 30 at the same speed as ring gear shaft 22. Spur
gear 36, in meshing engagement with ring gear 28, moves en-masse with the
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ring gear. The second crank pin 40 turns on the centerline of rotation of,
and at *he same speed as, ring gear shaft 22. Thus, there is no crank throw
to move the clutch shafts so there is no motion put to the output gears 58 of
the clutches, and sub-frame or carrier 24 is not made to turn. Likewise,
constraint gear 48 does not turn and thus constraint gear 84 fixed to the
master link, and -the master link itself, does not rotate.
Now, if control shaft 154 is turned to turn link 156 a new motion
ls added ~or subtracted~ to the control gears, turning shaft 30 relative to
ring gear shaft 22. This causes gear 36, in mesh with the ring gear, to
turn, causing secondary crank piTI 40 to move away from the zero throw posi-
tion. In this configuration, when shaft 30 is rotated, crank 40 will cause
the master link 44 to move in an orbital path about the axis of rotation of
shaft 22. This causes the connecting links 50, pivotally connected be-
tween the master link and cranks 52 of the clutches, to oscillate. The master
link is held against turning with respect to the sub~housing 24 by the con-
straint gearlarrangement 46~
In or~er or the clutch motions to be balanced and identical, it is
important that master link 44 not turn relative to the clutch shafts 90.
This is accomplished by the gear array previously described, including the
gears 48, 84, 130~136. By fixing gear 48 on housing 24 in a fixed position
with respect to the clutch shafts, so that it cannot turn relative to those
shafts, and by keeping it on the main centerline of the axis of rotation of
the housing, gear 84 is constrained against rotation, regardless of the posi-
tion of the master link and regardlass of how fast links 86, 140 swing
around the axis of rotation of the housing 24. (It is noted that except for
idlers 130, 136, these gears must all be of the same diameter). Since gears
13Z, 134 are not rotated gear 84 will not *urn either, regardless of how
~ast or slow its associated link 86 is moved. Thus, the mas*er link is held
r 12 ~
in a relatively flxed position.
As previously described all of ~he clutch houslngs are coupled by
the gears 58 to stator gear 60. When the shafts 90 of the clu-tches are
oscillated in the direction of rotation of the clutch housings, for driving
sub-frame 24, at a speed which is equal to or very slightly faster than the
speed of rotation of the clutch housing, vanes 106 will try to push oil out
through ports 114 so tha-t the shaft may continue to turn. ~lowever, there is
no place for the oil to go so i~ builds up pressure in the wedge-shaped area
in front of the vanes. This increased pressure is communicated through ports
116 to the space below the vanes, driving the vanes up against ring 98. As
a result, the rotor and housing are wedged together by a hydraulic wedge and
they turn together, transmitting rotary power to gears 58. As soon as shaft
90 and rotor 10~ start turning slower than the housing, or in an opposite di-
rection relative to the housing, high pressure wants to build up on the
other side of the vanes and a lower pressure is found on the side that was
previously pressurized adjacent the ports 114. This lower pressure, which is
now under the vane) combines with the higher pressure on the opposite side
of the vane to push and pull the vane away .from the clrcumference of the
housing so that the oil in the clutch can pass freely over the top of the
2Q vane ~rom one side to the other and the rotor is effectively declutched from
the hous~ng. In this embodiment of the invention the clutch functions
essentially as a one way overrunning clutch and the transmission only funct-
ions as a one way drive. In this form there is no reverse or load drive rom
the clutch.
Another embodiment of the clutch of the present invention is
illustrated in Pigures 11 and 12. This clutch is adapted to be used in an
automatic automob~le transmission ~or in any other situation where a reverse
driye is required), or where a load drive from the drive wheels of the ve-
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hicle to the engine is desired . It also shows means for making up oil that
might leak from the clutches. Simpllfied similar make up means may be used
on the first described clutch.
In this embodiment of the invention clutch shaft 90 is journalled
in a clutch housing 94 and has a pair of splined rotors 102 secured thereto
and located within a pair of complementary chambers 103 for:ned in the housing
within clutch rings 98. Rotors 102 have radially extending vanes 106 slid-
ably mounted in slots 104 therein, which vanes may be biased upwardly by
springs or the like 108. I'\s in the prior embodiment, clutch housing rings
98 provlde oval shaped cavities, as seen in Figure 12 of the housing. Al-
though two chambers 103 are used in this illustrative embodiment of the
clutch, it ls to be understood that the clutch can have a single chambe-r
103.
In this embodlment of the lnventlon the clutch housing is provided
with t~o pairs of ports, as shown in Figure 12 (wlth the ports in the re-
spective pairs being identified as 114a, 114b for clarity). The pairs of
ports are connected by separate passageways 190, 192, to a spool valve bore
194 formed in one end o~ the clutch housing. A banjo or slip ring 196 is
mounted in a fixed position on the housing and supplies hydraulic fluid
2Q through fittlngs 198 to ports 200 and 202 in the clutch housing which lead
to opposite ends of spool valve bore 194~ The latter slidably contains a
spool valve 204 having a through port 206 formed therein closed at opposite
ends by check valves or balls 208 biased apar~ by a centrally located spring
210. In this embodiment of the invention output gear 58 for the clutch
housing is integrally formed with the housing and transfer energy from or to
the clutch housing and thus from or to shaft 90.
Passageways 212 connect the center recessed portlon 214 of the
spool valve to high pressure rings or grooves 218 formed ln the housing of
.
s
the clutch adjacent the lower ends of the vane slots in rotor 102.
In operation, with the spool valve blocking passage 190; as seen in
Figure ll, when shaft 90 turns in a counterclockwise direction relative to
clutch ring 98 (as shown in Figure 12)pressure is put on oil leading to ports
114a and that same pressure connects through passage 192, spool valve 32,
and passage 212 to the high pressure rings 218 putting high pressure oil
under vanes 106, keeping them tightly sealed against housing ring 38 and
causing wedges of oil to be trapped between the vanes and rotor housing,
locking them together during this relative motion. When the relative
motions are opposite i.e. when shaft gO is oscillated in an opposite
direction during its cyclical operation, high pressure wants ~o build up on
the sides of the vanes associatedlwith the ports 114b, thereby lowering
the pressure appearing in ports 114a. The spool valve however blocks
passage of fluid from the port 114b so that no high pressure oil is fed to
rings 218 to push the vanes out to seal against the housing. Instead,
suction pressure is passed from ports 114a to beneath vanes 106 to pull the
vanes downwardly. Thus, instead of a high pressure oil wedge building up
between ~he right hand side of the vane, the rotor and the housing, the
oil that would normally form this wedge passes freely over the top of the
retracted vane, and the rotor free wheels relative to the housing. Thus,
the rotor and housing are declutched from one another and the whole clutch
acts just as a one way sprag clutch.
In order to reverse the clutching action, to get a reverse drive
or a load drive, spool valve 204 is simply moved to its other position, at
the other end of ~he bore 194 from that illustrated in Figure 11. This is
done by putting oil under pressure through the banjo 196 and down passage-
way 202 while the same time draining oil through the passageway 202 leading
to the other side of the spool valve.
The oil in spool valve bore 194 is under pressu-re during the spool
shifting operation. Since the spool valve bore is closed by check valves
204, if the pressure in bore 194 increases above the pressure of oil con-
tained within the clutch chambers due, for example, to a loss of oil through
leakage, the check valves will open to permit this shifting oil to enter
the clutch housing, and compensate for that lost oil. Thus, the ball check
valves keep the high pressure of the wedge clutch oil from leaking out, but
let the modest pressure of the shifting oil in during the suction portion
of the declutching cycle to make up lost oil.
Accordingly, it is seen that the clutch of the present invention
is adapted to serve as a one way or overrunning clutch, but it has no costly
sprags or teeth to wear out, and is selectively reversible. By operating
the spool valve with a governor device, it becomes a centrifugal clutch.
By controlling the speed of the!spool valve travel, especially when the
spool is tapered at one end, it becomes a slip clutch. The position of the
valve in the embodiment of the inventîon illustrated in ~he drawing can be
controlled in any convenient manner by the operator of the vehicle, and it
can even be connected to the foot pedal of the vehicle so that when the
operator's foot is released from the gas pedal, spool valve 204 is moved
from its leftmost position in Figure 11 to its rightmost position, so that
the drive of the wheels of the vehicle is transmi~ted back through the
transmission to ~he engine, to aid in slowing the vehicle down and prevent
the vehicle from coasting. Also, ~he spool can be constructed to block all
connections to the high pressure ring in one of its positions so that no
clutching occurs. In that position the clutches are declutched for both
directions of rotation.
Another embodiment of the variable throw crank of the present in-
vention is illustrated in Figure 13. In this embodiment of the invention
an alternative to the ring gear variable throw crank is provided, wherein,
in lieu of the joint shafts 22, 30, a single drive shaft 250 is provided
that is drivingly connected at one end 251 to the engine or motor through
gears 18, 20 or the like. This shaft has an eccentrically located bore or
chamber 252 formed at its end 253 and fluid passages 254, 256 are connected
at their left ends to a banjo 258 journalled on the shaft and to which oil
under pressure is supplied. These bores, as seen in Figure 14, lead to
opposite side of chamber 252 formed within the shaft 250. In this connec-
tion it is noted that chamber 252 is generally cylindrical in cross section
and a shaft stop element 258 is positioned within the shaft and secured
thereto by a screw 260 or the like. The stop element has a continuation of
ports 254, 256 formed therein.
A secondary crank shaft 262 is journalled within bore 252 in very
close relationship to stop 258, as seen in Figure 14. This crank shaft has
a vane 264 secured thereto which effectively divides chamber 252 into right
and left hand portions. In addition, crank shaft 262 includes an integral
eccentric pin 266 formed therewith and extending outwardly from sha-ft 250.
This pin 266 is offset from the axis of rotation of shaft 262 by a distance
equal to the offset of the axis of rotation of shaft 262 from the axis of
rotation of shaft 250 ~see Figure 13a). The end plate 268, bolted to shaft
250, closes the open end of chamber 252 and serves as a journal for shaft
262.
By supplying oil under pressure to one side of the chamber 252,
through one of the ports 254, 256, while relieving pressure from the other
port, shaft 262 will be rotated, thereby varying the position of crank pin
266. By supplying oil to the left chamber section as seen in ~igure 14,
and relieving pressure from the right chamber, the crank pin will be ro-
tated in a clockwise direction until vane 264 is stopped by engagement with
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stop 258, at which point crank p.in 266 is located in axial alignment with
the axis of rotation of shaft 25Q. By supplying oil under pressufe in the
opposite direction, the eccentricity of crank pin 266 can be varied. This
crank pin corresponds to crank pin 40 of the previously described embodiment,
and therefore when it is in an eccentric position with respect to the axis of
rotation of shaft 250, i.t will cause the master link or plate 44 to
oscillate, thereby driving the clutches associated therewith.
In this embodiment of the invention, it is noted that the torque
arm of the variable throw crank is the line from the center of main shaft
250 to the centcr of crank pin or shaft 262. This lin0 forms the base of
~n isoceles triangle whose apex is the center of bore 252. As a result,
the maximum ~urning torque on vane 264 is one half the input torque regard-
less of how big the output torque of the transmission using this crank might
be. Shifting oil comes from an auxiliary pump and is fed into the crank
position and through the fittings on banjo 258 and then through the
passages 254, 256 by either manual or automatic means.
Figure 14 also illustrates a system for au~omatically controlling
the throw of the crank pin 266 in response to engine speed and load. As
seen therein, a micro switch 300 is connec~ed to the gas pedal 302 of an
automobile to control the engine's throttle. When the pedal 302 is de-
pressed by the operator it opens the ~hrottle 304 o the engine ~o its
fwlly open position through a conventional throttle control system ~not
shown); and, when no pressure is placed on pedal 302 the th~ottle is fully
closed. The pedal 302 is also connected to a valve 306 through a linkage
307 which controls the supply of oil, under pressure from a source thereof
30B through valve 309 to the port 254 to urge vane 264 in a clockwise di-
rection, while connecting port 254 to drain.
In addition, the flywheel gove~no~ 31Q for the engine is used to
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control another valve 312 to control supply of oil under pressure from
source 308 to port 254. In this manner the positioning of vane 264 and
thus the throw of crank pin ~0 is controlled in response to the engine
speed and the load on the engine. Thus, if the engine is operating too fast
for the load Oll the transmission the valve 312 will supply oil under pressure
to valve 309 to shift the valve to the right and connect high pressure oil
to port 254 while connecting port 256 to drain, thereby to shift the trans-
mission to a higher gear ratio and thus slow the engine down. Accordingly
the transmission serves to mate the output to the load so th~,t the engine
operates at minimum efficiency.
This control system can also be used to control positioning of
cranks 155 of the previously described variable through crank by controlling
the supply of pressurized oil to the chambers of cylinder 161.
As with the clutches described above, the variable throw cranks
of the present invention can be usèd as products unto themselves, or in
other applications apart from drive transmissions. Thus applicant's in-
vention in the construction of these features is not limited to automobile
transmissions.
From the above it is seen that the output speed and torque of the
transmission according to the present invention are proportional to the
throw of the variable crank. When the crank throw is zero inches the output
shaft driven by the crank turns at zero speed regardless of how fast the
engine turns the crank or input shaft. When the crank throw is set at its
maximum the output shaft turns at its maximum speed. The top speed ratio
in the rever~ed transmission may be greater than 1:1, and at intermediate
throws the output shaft will be driven at intermediate speeds. The output
torque is inversely proportionate to the output speed. The construction of
the transmission is rugged and simple, and it can be manufactured at
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relatively low cost. In the transmission the crank thro~Y is easily changed
under load, and since the secondary crank is balanced by counterweights in
the illustrative embodiments, and since the total mass of the secondary
crank and the primary crank is also balanced by the counterweights, the
adjustable throw is always in near perfect radial balance.
Accordingly, the transmission of the present invention provides a
reversible, infinitely variable, positive drive torque multiplying trans-
mission of great simplicity and high efficiency. The device is low in cost,
can be made ln very small sizes or in extremely large sizes, is light in
weight and will be practically maintenance free. Because the transmissions
provide a far larger range of ratios than conventional *ransmissions, they
can halve the fuel consumption of a conventional automobile and allow
smaller engines to give superior performance.
Although illustrative embodiments of the present invention have
been described herein with reference to the accompanying drawings, it is
to be understood that the invention is not limited to those precise embodi-
ments, and that various changes and modifications may be effected therein
by one skilled in the art without departing from the scope or spirit of
this invention.
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