Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
FIELD OF THE INVENTION
This invent;on relates to rotary axial vane mechanisms
which may be used in pumps, compressors, fluid motors, internal
combustion engines, and the like; hence, these mechanisms may be
used for driving a fluid or for being driven by a fluid.
BACKGROUND OF THE INVENTION
The invention is particularly directed to that type
of rotary mechanism which contains ~wo annular working chambers
flanking a median casing wall. These chambers are closed by
coactingly shaped end walls disposed opposite to the median
wall and defining vane-guiding cam surfaces; these surfaces are
generated by revolving a radial line perpendicular to the axis
of rotation of the rotary mechanism. The chambers are sepa-
rated into several compartments by one or more vanes slidably
mounted in the median wall for longitudinally reciprocating
motion as they are engaged with both of the guiding cam surfaces.
Hence, the motion of the vanes is in a direction transverse to
the plane of rotat;on of the rotary mechanism.
The ;nvention is applicable in general to such
structure as described in U.S. patent Nos. 2,154,458 issued
April 18, 1939 to R.T. Knapp, 2,672,099 issued March 16, 1944
to J. Deubel, 2,593,457 issued April 22, 1952 to W. Jastrzebski,
2,462,622 issued April 5, 1949 to W.R. Tucker et al., 2,902,942
issued September 8, 1959 to M. Pelladeau and 3,489,126 issued
January 13, 1970 to K.N. Regar.
Irrespective of the particular arrangements used in
the above-listed patents, these mechanisms share several common
disadvantages:
(a~ cams and slots are expensive to make;
~b) vanes are too weak For long strokes and/or large
pressures;
(c) sliding friction between vanes in cases where several
vanes work in the same slot is high and causes sticking
and wear;
(d) cam-vane contact is limited to almost a linei hence~
poor sealing and excessive wear;
(e) vane-channel contact surface is quite limited; hence,
leakage and wear;
(f) in cases where the vanes rotate, the centrifugal forces
cause wear along the narrow longitudinal edge of the
vanes; and
(g) the contact line between the cam and the median wall
allows large leaks.
OBJECTS ARD STATEMENTS OF THE INVENTIQN
One object of the present invention is to overcome
most-of the d;sadvantages listed above w;th respect to prior
rotary mechanisms and to provide an axial rotary vane mechanism
adaptable to various functional applications.
The operation of the mechanism of the present
invention is based on the relative rotation imparted between
two inclined cam surfaces and a housing which contains at least
one transverse channel in its central wall and a cylindrical
~ane located in this channel; the vane has two end surfaces
remaining in continuous sliding contact with their corre
sponding cam surface. This relative rotation results in the
longitudinal reciprocating movement of the vane and in its
rotation about its own axis.
The present invention therefore relates, in its
broadest aspect, to a rotary axial vane mechanism which includes:
a hous;ng having a generally cylindrically shaped interior
profile and a median wall; means, located centrally of the
interior profité, having a generally cylindrical outer surface
defining with ~he interior profile and the median wall, on
OppQSite sides thereof, two separate annular chambers; a pair
of cam means respect;vely mounted in each chamber opposite to
the median wall, the cam means having coactingly shaped plane
surfaces`parallel to one another and in.clined with respect to
the longitudinal axis of the interior profile; at least one
cylindrical channel means extending through the median wall
and having an axis parallel to the longitudinal axis;
cylindrical vane means slidably and rotatably mounted in the
1~ channel means, the vane means having opposite inclined end 1¦
walls ;n coacting engagement with the cam surfàces whereby
relative rotation between the housing and the cam means results
in the rotation and in the longitudinal translation of the vane
means in the channel means.
The such defined mechanism may be uti-lized-in a pump,
an hydraulic motor, a compressor, a vacuum pump, a pneumatic
mo~or, a steam motor, an internal combustion engine and the ¦
like.
Other objects and further scope of applicability of
the present invention will become apparent from the detailed
description given hereinafteri it should be understood however
that this description, while indicating preferred embodiments
of the invention, is given by way of illustration only since
various changes and modifications within the spirit and scope
o~ the invention will become apparent to those skîlled in the
art from reading this description. One such mod;Fication
would involve separate chambers of different sizes, hence of
cylindrical channels and cylindrical vanes having two portions
of two differen~ diameters.
BRIEF DESCRIPTION OF THE DRAWINGS
Figuré 1 is a perspective exploded view of a rotary
mechani sm wi th rotati ng cam members and s~ationary housing in
accordance with one embodiment of the present invention, part
of one end cover and of the central cas.ing having been omitted
for clarity;
Figure 2 is an elevational cross-sec~ional view of
the rotary mechanism shown in Fig. l;
Figure 3 is a sectional perspective view of the dis-
charge ports, manifold and valving which may be used in a
mechanism such as t~e one illustrated in Fig. l;
Figure 4 is a transverse cross-section through the
median wall of a variant of the mechanism shown in Fig. 1 `
' illustrating transfer passages in a vane;
Figure 5 is a perspective exploded view of a rotary
mechanism with fixed cams and rotary housing in accordance
with anothe.r embodiment sf-the present invention, one half of
the casing, parts of the rotary housing and of the second half
of the casing having been omitted for-clarity;
Figure 6 is a longitudinal cross-sè~tion through a
hollow vane with closed ends;
Figures 7 and 8 are, respectively, an elevational
end view and a longitudinal cross-sectional view of the rotary
portion of a mechanism made in accordance with the present
invention with plane annular surface on the median walli
Figure 9 is a perspective view of a fixed cam member
cooperating with the rotor portion illustrated in Figures 7
and 8;
Figure lOa is a perspective view of a fixed cam
member in the first half stage of a second-stage compressor
constructed in accordance with the present inventioni
Figure lOb is a perspective view of a fixed cam
member in the sécond half stage of the said second~stage
compressor;
Figure 11 is an elevational side view of a rotor
cooperating with the cam members oF Figs. lOa and lOb;
F;gure 12 ;s an elevat;onal end v;ew of a rotor ;n an
internal combustion engine in accordance with the present
invention;
Figure 13 is a perspective view of a cam member
cooperating with the rotor of Fig. 12;
Figures 14a, 14b, 14c are end views of the cam member 1 .
of F;g. 13 with the successive positions of the three vanes.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the following description, the same reference
numerals will be used to designate identicai parts and .
configurations. As the rotary axial vane mechanism of the
present invent;.on ;nclude.s.two separate s;des divided by a
central wall and having therein generally iden~ical parts and 1.
configurations in the.drawings, the refe.rence numerals shown
on the left-hand side of the central wall will bear the
subscript "a" while those on the right-hand side will bear the
20 subscript "b". :
The mechanism shown in Figs. 1 and 2 ill.ustrates a
stationary housing 10 having a generally cylindrically shaped
interior profile 12 separated by a centrally disposed partition
median wall 14 having outer opposite identical conical surfaces
16 and cylindrical extensions 20. Each ;nterior profile 12,
conical surface 16 and cylindrical extension 20 define an
annular chamber 18 These chambers 18 are closed by a pair of
cam members 24, each haYing an inclined plane surface 22; these
cam members are identically shaped and their surfaces 22 are
parallel to one another and inclined with respect to a central
shaft 26 which longitudinally traverses the housing 10. The
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.
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angle which the cam surfaces 22 make with the longitudinal axis
of the shaft is the same as the vertex angle o~ the conical
sur~aces 16. The cam members 24 are fixedly mounted on shaft 26
by appropr;ate keys 27 received in grooves 28 so that the
inclined surface planes remain constantly parallel to one
another. By being keyed to the shaft 26 in the position shown
in Figures 1 and 2, the long;tud;nal d;stance separating the
inclined surfaces 22 is constant. The outer and inner
ellipt;cal per;pheries 30 and 32 of each cam surface maintain
small running clearances with respect to the outer and inner
cylindr;cal walls 12 and 20 of chambers 18. Each ;nclined face
' of the cam members has a recessed radial segment 34 which
engages with the respective conical surface 16 across a small
running clearance. The housing 10 is closed at its opposite
ends by two cover plates 36 by means of bolts 38. These plates
contain the outer races 40 of tapered roller bearings 42, the
inner races of which are mounted on shoulders 44 of the
respective cam members; this arrangement offloads the shaft of
bending stresses.
A cylindrically shaped channel 46 in the median wall
14 extends parallel to the axis o~ shaft 26 and has a diameter
sligh~ly exceeding the annular width o~ chambers 18. The inner
walls 20 and the outer walls 12 include oppositely facing
concave recesses 48 and 50 which def;ne arc surfaces in
~rolongation with the inner wall surface of channel 46 so that
a cylindrical vane 52 may extend through channel ~6 and be
contained between the opposite recesses 48 and 50. The
cylindrical vane 52 has opposite end walls 5~ and 56 which are
inclined and parallel to one another and which make the same
angle as the inclined plan~ surfaces 22 with respect to the
shaft 26. The iength of vane 52 is substantially equal to the
constant distance separating the cam surfaces 22 so that the
inclined faces 54,5~ of the vanes are constantly in contact
with the cam surfaces.
Vane 52 and each recessed segment 34 divides each
corresponding chamber into two working chambers; as the sha~t
rotates, so do the inclined cam surfaces and the vane is
forced tO reciprocate longitudinally and to turn once around
its own axis for every turn of shaft 26. Simultaneously, the
recessed se9ment 34 revolves with the inclined cam surface and
together with the vane causes a cycl;c volume change for each
of the corresponding two working chambers. The volume changes
in the two working chambers of ~he other half occur with a
phase angle of 180. The increasing volume of a working chamber
draws in fluid from an intake manifold 58 through a port 60
extending longitudinally in each interior pro~ile of the
housing lO along the recess 50;-the:manifold~58 is connected
to appropriate fluid drawing means.through port.62.in the cover
plate 36. Simultaneously, the decreasing volume of the second
working chamber expells the fluid, already admitted during the
previous cycle, through a port (not shown but extending
longitudinally and adjacent to the recess 50) into an exhaust
manifold 66. The exhaust manifold is also connected to
external fluid receiving means through a port 68 provided in
cover plate 36.
Although the inertia forces associated with a hollow
vane such as 52 are quite small, it is preferable in larger
units to use a balancing member 70 which is ident;cally shaped
to the vane 52 but has a smaller diameter and weighs just as
much. The balancing member is located at 180 with respect to
the vane 52 and reciprocates parallel to the shaft within a
channel 72 provided in median wall l4 and parallel to vane
.
channel 46; its role is to reduce the level of vibration.
Leaks across various running clearances between ,
parts in relative motions are m,inimized by relatively wide
mating surfaces, such as recesses 34, 48 and 50 and also by
grooves ;n these mat;ng surfaces. Each such groove acts as
a cavity interposed between the regions of higher and lower
pressures; the c'avity fills up with fluid and the resulting
inflow and outflow are substantially smaller than the leakage
flow which would have ex;sted otherw;se in the absence of the
cavity. Indeed, each radial segment 34 has a radial groove
74 in its central port;on; each cam 24 has a circular groove
' 76 and long;tudinal serrat;ons 78 aruund its outer periphery
and another circular groove 80 around its inner periphery.
The longitudinal concave recesses 50 and 48 have longitudinal
grooves 82 and 83, respectively, located in their middle.
The hollow interior of vane 52 acts as a leak reducing cavity.
The cover at the shaft's drive end is equipped with
an axial seal assembly which consists of: a stationary sealing
disc 86 having an appropriate bearing surface and secured to
the cover plate 36, a rotating sealing disc 87 slidably mounted
on shaft 26 and spring loaded against disc 87 by a spring 88.
An "O"ring 84 in the sealing disc 87 prevents leakage along
the shaft.
The pressure builds up behind the cams 24 because of
the axial seal assembly and the closed cover plate at the other
end of the mechanism; this in turn causes a further reduction
in leaks and a d;minished axial load on the roller bearings.
The inlet ports 60 and the outlet ports 64 located ;n the
cylindrical interior profile of the chambers are progressively
uncovered by the outer peripheries of the cam members as the
rate of volume change increases, the maximum occurring when the
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vane is fully extended. This feature provides constant speed
of flow through the ports if the fluid is a liquid; moreover,
the combined inflow rate to both halves of the mechanism remains
also constant, the same occurring wi th the outflow; the result
is r;pple-free flow. Furthermore, the theoret;cal torque
absorbed or developed by the mechanism remains substantially
constant and provides a smooth operation. The intermediate
pressure established on the vanes end surfaces and on the
balancing member 70 end surfaces has a balancing effect and
allows a smooth travel of these members over the inclined
surfaces. In addition to their sealing roles, the longitudinal
' recesses 48 and 50 act as effective guides and bearing
surfaces for vane 52 and allow the use of long strokes and
high pressure differences in the mechanism.
For rotary axial vane mechanisms of relatively small
size, the inner cylindrical wall portio.ns 20 are preferably
bolted to the median wall.14 rather. than being an integral
part thereof as shown in the drawings; this provides an easier
machining of the conical surfaces 16; the vane 52 may also be
made of solid l;ghtweight material and the roller bearings may
be replaced with plain bushings, self-lubricated or not.
The rotary mechanism of.the present invention operates
as a motor if the fluid at the intake is at higher pressure
than at thé exhaust and it operates as a pump in the opposite
case. The pressure difference between a set of two working
chambers is exerted on the respective inclined faces and
produces a resisting or a.driving torque on the shaft as the
case may be.
With equal sized ports, the mechanism shown in Fig.
1 is both reversible in direction and function. It could
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operate as a gas motor in which case the gas is discharged
without any expansion within the working chamber; the resulting
higher gas consumption is, however, tolerable in small sized
motors where compactness is essential.
By providing automatic discharge valves at the
exhaust ports 64, the mechanism of Fig. 1 could be operated
as a gas compressor. Fig. 3 shows a reed valve 90 secured
midway to the median wall 14; the ports are equipped with
valve seats 92a, 92b and the access to the valve assembly is
provided by an opening 94 in the outlet manifold 66; this
opening is closed with a cover (not shown).
Fig. 4 shows a cross-section through the median wall
14' of a variant of the present invent;on where the solid vane
52' carries, around its outside, four fluid transfer passages
~6 which consist of- longitudinal grooves communicating cycli-
cally with ports 60' and 64' located in the median wall. Such
an arrangement-eliminates-the ports and the-ma-nifolds in th-e
outer cylindrical walls; i~ is, however, applicable only to
small units because of the inherent limitations of the transfer
passages.
Fig. 5 shows an energy converting mechanism 100 in
~ccordance with the present invention which retains the basic
principles of the unit shown in Fig. 1, but is designed par-
ticularly for gases; it provides a built-in compression or
expansion ratio, as the case may be. The unit, as shown, has
three equally spaced vanes 102 (I, II, III) within channels
104 (I, II, III) made in housing 106; these vanes are hollow
and closed at both ends as shown in Fig. 6, they may also be
solid. The housing 106 is the rotor and is keyed to the shaft
108 by appropriate means (not shown). The pair of cams 110
with inclined surfaces 112 are fixed at their respective
-- 1 0 --
bottoms of the two outer casing halves 114i these halves are
bolted toge~her and contain appropriate inlet and outlet
manifolds (not shown) as well as attachment lugs 116. In a
sl;ghtly different arrangement ~not illustrated), the outer
casing may consist of a pipe-like portion closed at both ends
with covers containing the cams and the means for external
support. The covers are bolted to the pipe or held together
with tie bolts. The inlet ports 118 and outlet ports 120 are
located in the inclined surfaces 112 and communicate with their
respective manifolds in the outer casings 114. The inclined
surfaces engage the respect;ve con;cal surfaces 122 of the
rotor over recessed segments 124; this feature means that in
a compressor of this design, the clearance space is almost
nil. The number of vanes dictates the compression or expansion
ratio attainable in the device; a minimum of two vanes is
required for effecting compression or expansion and for
balancing centrifugal forces as well as reduci-ng the vibrations.
The ratio is defined as that between the maximum volume confined
between two consecutive vanes and the volume reached as the
leading vane is just uncovering the outlet port. The com-
pression ratio for three vanes is about 4.3. In the position
shown in Fig. 5 and considering the direction of ro~ation
when operating as compressor, the vane 102-I is expelling the
gas through port 120b; the gas confined between the vanes
102-III ànd 102-I is being compressed; the space between 102-II
and 102-III is being f;lled with fresh gas arriving through
port 118b.
In a device operating as a gas motor, the high
pressure gas is admitted through port 120b and the force
exerted on vane 102-I drives the rotor 106 ln the opposite
direction to that of the arrow 126. When the next vane 102-II
1 1
., . .. , . , :. :
p~sses by port l20b, the working chamber between 102-I and
102-II stops being.charged with h;gh pressure gas; as the
rotor continues to turn, this charge expands until the volume
of the working chambers reaches a maximum (this happens when
the vane 102- I i s at 240 and 20- I I at 120 with respect to
the radial segment 124b, the angles being measured in the
direction of rotation); further rotation brings ~he expanded
gas in communication with port 118b through which it is dis-
charged. Some compression occurs as the vanes approach the
radial segment after.having discharged the gas and helps ;n
reducing leaks across the segment.
The a~orementioned compression or expansion oper-
ations occur for any numbers of vanes exceeding one, the only
difference being the compression or expansion ratios attained
in the operation.
As compared with the rotating cam design, the fixed
cam approach.ne-cessitates more complicated inlet and outlet
manifolds s;nce the ports in the two halves are on the opposlte
sides. On the other hand, the fixed cam design provides a
larger displacement within the same frame.
The features used in the rotating cam design for
reducing the various leaks are also incorporated in the .fixed
cam designs. The end faces of the outer and inner cylindrical
walls 128 are prov;ded with circular grooves 130 and 132 and
the closed ends of the vanes include small recessed cavities
174. Sealing can be substantially improved by injecting oil
in the working chambers, which provides, at the same time,
lubrication and internal cooling. The oil must be subsequently
separated from the discharged mixture, cooled, and sent to a
tank from which it is drawn again into an active cycle.
~, '
Figures 7, 8 and 9 show a variation of a multi-vane
design: the aforementioned radial segmen~s do not ex;st
because the conical surfaces of the median wall are now
replaced with plane annular surfaces 134. The unit contains
two close-end vanes sliding in bores 136-I and 136-II located
at 180 from one another. The ports 138 and 140 of the cams
142 are located in the inclined surfaces 144, on the minor
axis 145 of the ellipses defined by the inner and outer
peripheries of the cam surfaces 144 and are fully covered and
uncovered by the vanes as they rotate with the rotor. If the
rotor turns as shown by arrow 146 in Fig. 7, port 140 stays in
communication with an expanding working chamber while port 138
does the opposite; the fluid is drawn in through 140 and
expelled through 138. Because the m;nimum volumes of the
working chambers are quite substantia-l, this arrangement is
best suited for pumps and motors using liquids.
The side-by-side location of the two halves in any
energy converter in accordance with the present invention lends
itself very well to the use of two different functions in the
two halves provided the two fluids are compatible with each
other from a chemical standpoint. The choice of a particular
design (fixed or rotary cams) depends upon the nature of fluids
involved.
In one such variation, one side acts as a fluid motor
driven from a source of high pressure fluid whereas the other
side acts as a l;quid pump, vacuum pump or compressor for a
second fluid. In another variation, one side acts as a first
stage pump for a liquid while the other acts as the second
stage.
In still another variation, one side acts as a first
stage compressor while the other acts as the second stage, the
fluid being intercooled between stages. Such a compressor
contains four vanes and fixed inclined cam surfaces as shown
in Figs. lOa and lOb. The "a" side acts as the first stage
while the "b" side acts as the second stage. The port ar-
rangement shown on the inclined surfaces 146a, 146b corresponds
to the direction of rotation of the rotor as indicated by
arrow 148 in Fig. 11. ~he ports 149 are for admission, while
ports 150 are for evacuation. Their wide variations in size
result from the fact that the physically equal displacements
of both sides have to be drastically modified to accommodate
the variations in densities in the second stages.
If the gas admitted in the first stage is air from
an enclosure and is discharged into the atmosphere at the
second stage outlet, the resulting mechanism is a two stage
vacuum pump.
Another embodiment consists of one side acting as an
internal combustion engine with fuel injection and plug
ignition, and the second side acting as a compressor. The
embodiment uses the fixed cam approach with a rotor which
possesses three vanes. The compressor section is built and
operates in the manner already described above. The internal
combustion engine presents several features which appear in the
Figs. 12 and 13; the inclined cam surface 151 maintains a
certain clearance with respect to the conical surface of the
median wall in the housing and contains an exhaust port 152,
an admission port 154? a fuel injection nozzle 156, and an
ignition plug 158.
In Fig. 14a, the vane 160-II has just passed the
ignition plug and is expelling the combustion gases previously
generated between vanes 160-I and 160-II. Vane 160-III has
just passed the fuel injection nozzle and the compressed air-
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fuel mixture trapped between 160-II and 160-III is ignited at
the plug end. Vane 160-I is starting to compress the air
previously admitted between 160-I and 160--III and the fuel
in3ection nozzlè is just starting to inject fuel into the a;r
being compressed.
In Fig. 14b, vane 160-II is pushed by the burning
mixture and the expanding gases confined between 160-II and
160-III; vane 160-II continues to expell the exhaust gases
through port 152 while simultaneously air from a supercharger
driven by the engine itself is being admitted through port 154.
Tlle supercharged air is oriented towards vane 160-I by the
'inclinat;on of port 154 and tends to f;ll the space to the
right thereof before escaping partly through port 152, thereby
providing a scavenging action. The charge in the working
chamber between 160-I and 160-III is being compressed and,
at the same time, enriched by the incoming fuel through the
injection nozzle 15-6-. In the working chamber between 160
and 160-III, the flame front ~ravels towards the approaching
vane 160-III thereby providing a good, progressive combustion;
simultaneously the already burnt gases expand towards vane
160-II.
In Fig. 14c, the three vanes have temporarily closed
the ports, the plug and the nozzle; the working chamber between
160-I and 160-II contains supercharged air with very little
residual exhaust gases left after the previous scavenging
action; the working chamber between 160-I and 160-III contains
a charge of fuel-air mixture of correct concentration and at
high pressure, this charge being ready to ignite as soon as
vane 160-III uncovers the ignition plug 158; the working
chamber between 160-III and 160-II contains combustion gases
which exert a pressure cn vanes 160-III and 160-II with the
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latter carrying a far greater forcei these gases are ready to
be ex~elled as soon as vane 160-II uncovers port 152.
There are three explosions per revolution and there
is always a net driving torque for driving the next room
compressor and the other auxiliaries such as: fuel injection
pump, the supercharger, etc. These aux;l;a-r;es are not shown
nor discussed because they are like any other standard
equipment used on existing engines. The fuel injection occu-rs
continuously as the successive air charges between consecutive
vanes are being compressed to the final pressure dictated by
the compression ratio; the injection is interrupted only for
a brief moment when a vane covers the nozzle.
The ignition plug could produce sparks at the right
moments (hence, three sparks per revolut;on) or it could be o~
the type which remains continuously incandescent (glow plug)
and ignites any fresh charge which contàcts it.
Since the combustion occurs always at the same
location, the unit requires cooling which could be done by
circulating oil through the rotor and the inclined cam
surface 151.
Since oil flooding of the working chambers is
imposs;ble, the sealing must rely on additional sealing
elements such as the longitudinal strips 164 and 165 loca~ed
as shown in Fig. 12, respectively, in grooves 166 in the
outer cylindrical wall 168 and in grooves 170 in the inner
cylindrical wall 172. The strips 164 are forced by the
pressure differences against the longitudinal walls of the
grooves and against the outer periphery of the respective
vane. As already mentioned, and as shown in Fig. 6, the
small cavities 174 at the inclined closed ends of the vanes
reduce the leaks across the cam surface-vane end clearance.
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. . . .
Sufficient lubrication is provided by the next room
flooding with oil. The rotor crown has an external gear 176
which is engaged by the pinion of a starting motor.
If the compressor section is replaced with another
identical internal combustion engine section, the resulting
combination would be an internal combustion engine capable of
dr;ving loads outside its own frame. Such an arrangement
requires a lubricating oil pump in addition to all the other
auxiliaries already mentioned.
