Note: Descriptions are shown in the official language in which they were submitted.
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ROTARY MOTOR WITH INTERMITTENT MOVEMENTS OF THE ROTORS
FIELD OF THE INVENTION
THIS invention relates to a novel rotary motor.
BACKGROUND TO THE INVENTION
Rotary motors are well known for use in a wide variety of applications,
including
internal combustion engines for vehicles, compressors, pumps and the like.
A wide variety of rotary type internal combustion engines have been proposed
and
developed in the past. In particular, the Wankel rotary engine is well known.
This
includes a substantially laminar rotor member which revolves about a moving
axis.
The rotor member is a laminar plate in the shape of a triangle having convex
sides.
The plate rotates about the moving axis within a chamber, which is configured
and
dimensioned to be slightly wider than the width of the plate member, and
having a
inner shape which complements the rotated shape of the plate member.
Further, a variety of compressors and engines are known which incorporate
rotor
members having vane-type shapes.
OBJECT OF THE INVENTION
It is an object of this invention to provide a novel rotary motor that
provides a useful
and functional alternative to the prior art. The term "rotary motor" herein
includes
both an internal combustion engine and a compressor, pump or the like.
SUMMARY OF THE INVENTION
According to the invention there is provided a rotary motor comprising:
- a first rotor member rotatable about a first axis;
- a second rotor member rotatable about a second axis; and
- a transmission system for rotating the first rotor member and the second
rotor
member; characterised in that
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- the first rotor member and the second rotor member are adapted to rotate at
variable angular velocities.
Also according to the invention the angular velocity of the first rotor and of
the second
rotor differ from one another during a rotational cycle of the motor.
Preferably through
3600 in respect of each rotor.
Further according to the invention the first rotor member and the second rotor
member may be dimensioned and configured to enclose a compression chamber
between them as they rotate.
Thus the first rotor member and the second rotor member may each include vanes
extending radially outwardly and having receiving formations between them,
with the
receiving formations of the first rotor member being dimensioned and
configured for
receiving vanes from the second rotor member and the receiving formations of
the
second rotor member being dimensioned and configured for receiving vanes from
the
first rotor member during rotation of the rotor members.
The first rotor member and the second rotor member may be rotationally coupled
to
each other by means of a transmission system.
The transmission system may comprise a plurality of gears, which may be
partially of
a first radius and partially of a second radius.
The gears may be of variable radius.
In one arrangement of the invention the transmission system may be adapted to
drive the first rotor member at a first angular velocity and the second rotor
member at
a second angular velocity for at least part of a revolution, and then drive
the first rotor
member at the second angular velocity and the second rotor member at the first
angular velocity for the complementary part of the revolution.
The first axis may be parallel to the second axis and the first rotor member
and the
second rotor member may be enclosed on two sides by a housing to form chambers
within the housing.
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Further according to the invention, each vane terminates at its free end in a
radially
expansible section adapted to follow the contour of the chambers in the
housing.
With such an arrangement, the housing could be extended radially outwardly at
opposed zones thereof to form a generally elliptically shaped structure.
The rotary motor in the form of an internal combustion engine may further
comprise
an inlet passage for introducing air into the compression chamber and an
outlet
passage for exhausting gasses from the compression chamber; means for
introducing fuel into the compression chamber at predetermined zones; and
ignition
means for igniting fuel introduced into the compression chamber.
These and other features of the invention are described in more detail below
without
limiting the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of the invention is described below by way of example only and
with reference to the accompanying drawings, in which
Figure 1 shows a schematic perspective view of an internal combustion
engine according to the invention, without the housing;
Figure 2 shows a schematic front view of a first rotor member and a
second rotor member and transmission as shown in Figure 1;
Figures 3a to 3f are schematic plan views of the first rotor member and the
second rotor member and their movement relative to each
other;
Figures 4a to 4d are schematic plan views of the gears in the transmission
system to cause movement of the rotor members;
Figure 5 is a graph of the angular position of a first rotor and a second
rotor against the angular position of the drive shaft during one
revolution of the transmission system;
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Figure 6 is a schematic illustration of an inlet port and an outlet port in a
side plate which forms part of the housing of the motor of the
invention;
Figure 7 is a schematic plan view of a first rotor member and a second
rotor member wherein radially outwardly directed vanes of the
rotors each include an extensible front end section;
Figure 8 is a schematic plan view of opposed chambers within the first
rotor member and the second rotor member rotate, such
chambers being extended outwardly to modify the
compression and expansion characteristics of the motor; and
Figure 9 is a schematic perspective view of a timing arrangement which
duplicates the movement of the vanes of the first rotor member
and the second rotor member.
DETAILED DESCRIPTION OF THE DRAWINGS
With reference to the drawings, in which like numerals indicate like features,
a rotary
motor, in this instance an internal combustion engine, is generally indicated
by
reference numeral 10. In a different configuration, not shown, the rotary
member
could also be applied as a compressor, pump or the like.
The internal combustion engine 10 comprises a first rotor member 20 rotatable
about
a first axis embodied by a first rotor shaft 30; a second rotor member 40
rotatable
about a second axis embodied by a second rotor shaft 50 parallel to the first
rotor
shaft 30; and a gear system 60 for rotating the first rotor member 20 and the
second
rotor member 40; wherein the first rotor 20 member and the second rotor member
40
are adapted to rotate at variable angular velocities, and at different angular
velocities.
In the embodiment shown, the first rotor member 20 and the second rotor member
40
are dimensioned and configured to enclose a combustion chamber 200 between
them as they rotate, as shown in Figures 3a to 3f. The first rotor member 20
and the
second rotor member 40 both have engagement surfaces 21 and 41 respectively on
opposing sides of each rotor. Operationally, the rotors 20 and 40 will be
enclosed on
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either side by a housing shown schematically at 55 to prevent combustion
outlet
gasses escaping from the sides of the rotors 20 and 40 in operation. The
housing
can comprise a pair of plate members 56 located on either side of the rotors
20 and
40. It is envisaged that the flat sides of the rotor members 20 and 40 will be
sealed
5 against the plates by a suitable sealing means (not shown). The housing 55
includes
a pair of circular chambers 56 which intersect as shown in Figure 8 and within
which
the rotor members 20 and 40 rotate. With reference to Figure 8, the generally
circular chambers 56 can be modified for example by a radially outward
extension 57
on the periphery thereof in order to modify the compression and expansion of
the
combustion chamber 200 as explained in more detail below.
The first rotor member 20 and the second rotor 40 member each comprise a
plurality
of vanes 25 and 45 respectively, extending radially outwardly and having
receiving
formations 26 and 46 respectively, between them, which receiving formations 26
and
46 are dimensioned and configured for operationally receiving vanes from the
other
rotor member. In one embodiment of the invention, the free ends of the vane
formations 25 and 45 will be provided with radially extensible end sections
25a and
45a which are adapted to follow the curvature in the receiving formations 26
and 46.
Such extensible end sections will also be able to follow the periphery of the
internal
chambers 56, Figure 8, where these are enlarged radially outwardly as shown by
the
area 57. As stated above, the enlarged area 57 will influence the entrainment
of air
into the chamber 57, the compression thereof, and the expansion of combustion
gasses.
With reference to Figure 1, the gear system 60 couples the first rotor member
20 and
the second rotor member 40 to each other so that they may only move through a
predetermined sequence of movements relative to each other. The gear system 60
comprises a plurality of gears and shafts, including the drive gear set 70
located on a
drive shaft 73, the first timing gear set 80 located on a first timing shaft
100 and the
second timing gear set 90 located on a second timing shaft 110.
The drive gear set is comprised of a large size gear 71 and a small size gear
72
located next to each other on a drive shaft 73. The tooth set of the large
gear 71
extends for only 180 degrees around the drive shaft, while the tooth set of
the small
gear 72 extends around the complementary 180 degrees of the drive shaft 73.
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Similarly, the first and second timing gear sets 80 and 90 are comprised of
large
gears 81 and 91, and small gears 82 and 92 located next to each other on the
first
and second timing shaft 100 and 110. The tooth sets of each of the large gears
81
and 91 extends around the first and second timing shafts 100 and 110 for 90
degrees, while the tooth sets of each of the small gears 82 and 92 extends for
270
degrees (the complementary angle) around the first and second timing shafts
100
and 110.
The first timing gear set 80 and the second timing gear set 90 communicate
with the
drive gear set 70 (as shown in Figures 4a and 4d) so that at some stages the
larger
gear 71 of the drive gear set 70 drives the smaller gears 82 and 92 of the
first timing
gear set 80 and the second timing gear set 90 respectively, and at other
stages the
smaller gear 72 of the drive gear set 70 drives the larger gear 81 and 91 of
the first
timing gear set 80 and the second timing gear set 90 respectively.
This interaction of the smaller gears with the larger gears at various stages
will result
in the first rotor member 20 and second rotor member 40 having different
angular
velocities at different stages during one revolution of the drive gear set 70.
A graph of
the angular velocities of the first and second rotor members 40 and 20 is
shown in
Figure 5. The graph shown in Figure 5 need not be comprised of linear lines,
and
could for example have curved zones, in the lower graph prior to exchange of
direction, and in the upper graph prior to the end thereof. The effect will be
that the
compression and expansion chambers of the motor of the invention will be of
unequal maximum volumes.
The first timing gear set 80 and the second timing gear set 90 drive a first
timing shaft
100 and a second timing shaft 110 respectively. The first timing shaft 100 and
a
second timing shaft 110 in turn drive a first reduction gear set 120 and a
second
reduction gear set 130 respectively, which drive the rotor members 20 and 40
in
opposite directions through a first final drive cog 140 and a second final
drive cog
150.
It is envisaged that both the small gears and the large gears for each of the
drive
gear set 70, the first timing gear set 80 and the second timing gear set 90
can be
incorporated on a single gear cog, or a continuously variable transmission may
be
used. It should be noted that the results achieved by the gears described
herein
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could be achieved by various arrangements of gears, not shown, and the
invention is
not limited to the gear arrangements illustrated in Figures 4a to 4d.
The second reduction gear 130 set has an extra reversal cog 131 to allow for
the
reversal of direction of the second rotor member 40.
In addition to the timing gear sets 80 and 90, there are various alternative
arrangements, whereby movement of the rotor members 20 and 40 can be
controlled. One such arrangement is for example shown schematically in Figure
9
wherein templates 63 which could be secured to the axes 30 and 50 of the
rotors 20
and 40 respectively are provided, the templates including cam formations 61 in
the
form of grooves which equate the movement of the vanes 25, 45. Such cam
formations 61 are followed by followers in the form of pins 62. The template
63 and
follows 62 will thus duplicate the movement as the rotors 20 and 40. Doubtless
other
variations are also possible.
The rotary motor operating as an internal combustion engine 10 further
comprises an
inlet passage shown schematically at 51, Figure 6, for introducing air 52 into
the
combustion chamber 200 formed by the rotors 20 and 40. Further, the internal
combustion engine 10 comprises an outlet passage shown schematically at 53,
Figure 6, for exhausting combustion gasses 54 from the combustion chamber 200.
It
is also contemplated that the internal combustion engine 10 comprises means,
such
as fuel injectors (not shown) or a carburettor (not shown) for introducing
fuel (not
shown) into the combustion chamber 200 at predetermined points, either by
injecting
it directly into the combustion chamber 200 or letting it flow into the
combustion
chamber 200 together with air introduced through the inlet passage.
The internal combustion engine 10 also includes ignition means (not shown),
such as
a spark plug, for igniting the fuel and air mixture in the combustion chamber
200. It is
envisaged that high compression within the combustion chamber 200 may allow
the
use of diesel or other similar fuels for compression-ignition operation.
Operationally, drive gear set 70 will drive the first timing gear set 80 and
second
timing gear set 90. The drive gear set 70 and the respective timing gear sets
80 and
90 are arranged so that, for each revolution of the drive shaft 73, the first
timing shaft
100 is driven at a different angular velocity relative to the second timing
shaft 110 for
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at least part of each revolution, after which the angular velocities of the
first and
second timing shafts 10 and 110 are reversed as shown in Figure 5.
The timing shafts drive the first reduction gear set 120 and the second
reduction gear
set 130, which then drive the first rotor member and the second rotor members
respectively. The direction of the second rotor member 40 is reversed by the
inclusion of the reversal cog 131 in the second reduction gear set 130, so
that the
first rotor member 20 and second rotor member 40 turn in opposite directions
as
shown in Figures 3a to 3f.
Figures 3a to 3f show how the rotor members 20 and 40 rotate relative to each
other.
In Figure 3a, the first rotor member 20 is rotating faster than the second
rotor
member 40. As a vane 25 on the first rotor member 20 is received into a
receiving
formation 46 (disposed between the two vanes 45 on the second rotor member 40)
on the second rotor member 40, an enclosed combustion chamber 200 is formed.
At this stage, a combustible mixture of air and fuel shown at 52, Figure 6, is
introduced into the combustion chamber 200. It is envisaged that this mixture
may be
introduced by known means, such as by using a carburettor and introducing the
mixture through the inlet, or by injecting a fine mist of fuel into the
combustion
chamber 200 by means of a fuel injector (not shown) to mix in the combustion
chamber 200 with air introduced through the inlet passage. In one arrangement,
small auxiliary combustion chambers 22, Figure 2, in the vanes 25 and 45 as
illustrated may be provided to enhance the combustion process. It is envisaged
that
fuel injection will be directed to the small chambers 22.
As the first and second rotor members 20 and 40 continue rotating at unequal
angular velocities, the combustion chamber 200 becomes reduced in size,
thereby
compressing the fuel and air mixture (as shown in Figures 3b and 3c). At the
stage
shown in Figure 3c, the angular velocities of the first and second rotor
members will
change so that the slower rotor member (the second rotor member 40) will now
become the faster moving of the two rotor members 20 and 40, and vice versa
for the
first rotor member 20.
The compressed fuel/air mixture 52 in the compressed combustion chamber 200 is
now ignited by the ignition means. The ignition of the fuel/air mixture causes
expansion of the gasses within the combustion chamber 200. The combustion
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chamber 200 expands, driving the second rotor member in an anticlockwise
direction
as shown in Figure 3d. Simultaneously, another combustion chamber 200 is being
formed by the interaction of the vanes and receiving formations on the first
and
second rotor members 20 and 40 as shown in Figure 3e. It has been found that
prior
to the formation of the closed combustion chamber 200 in Figure 3a, the volume
thereof is decreased and excessive air is ducted into the adjacent chamber 201
whereby the pressure in the adjacent chamber 201 is increased to greater than
ambient air pressure. It will be noted that the same effect occurs as the
chamber 201
is reduced in volume by the interaction of the vanes 25 and 45 for example as
shown
in Figure 3c and 3d. The result of such transfer of fluid results in a greater
efficiency
of the internal combustion engine.
The combustion gasses 54 in the combustion chamber 200 are then exhausted
through an outlet passage 53 in the housing 55. The outlet passage 53 may be
located to the side of the rotor members 20 and 40 in the housing 55, Figure
6.
It can be seen that the expansion of gasses in the ignited fuel/air mixture in
the initial
combustion chamber 200 in Figures 3a and 3b help to compress the fuel/air
mixture
for the following combustion chamber 201 being formed in Figures 3e and 3f.
It is envisaged that this basic principle of operation may be used in a wide
variety of
configurations, and that a wide variety of shapes may be used as rotor members
20,
40, in order to maximise the volume of fuel/air mixture 52 compressed, or to
maximise the time during which the ignited fuel air mixture acts against the
vanes 45.
It is envisaged that the gear system 60 may be a planetary type gear system.
It is
further envisaged, due to the elongated shape of the combustion chamber 200,
that
two ignition means, in the form of spark plugs, may be used to ignite the fuel
air
mixture 52 at either end of the combustion chamber 200. For the same reason,
it is
preferable to employ two fuel injectors, not shown, in spaced relationship for
the
elongate combustion chamber 200.
It is further envisaged that the vanes 25 and 45 and receiving formations 26
and 46
of the rotors 20 and 40 may include combustion enhancing formations to enhance
combustion efficiency.
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It will be appreciated that the above is only one embodiment of the invention,
and
that many variations in detail are possible without departing from the scope
of the
invention. For example, a set of rotor members may be arranged in a circular
formation around a single inlet passage 51 or outlet passage 53. Also, rotor
5 members 20, 40, with less pronounced vanes 25, 45, may be used for purposes
of
strength or reliability, and in a wide variety of shapes. In a further
embodiment, it is
envisaged that a plurality of rotor members 20, 40, may be located around a
single
central rotor member so as to cause the formation of a plurality of combustion
chambers with the central rotor member. In an even further embodiment, it is
10 envisaged that one of the interacting rotor members 20, 40, may be held
stationary
while one or more rotating rotor members may rotate around the stationary
rotor
member, while still interacting with the stationary rotor member in the same
manner
as described above. It is further envisaged that in such an embodiment, the
plurality
of rotor members rotating about the stationary one rotor member may be phased
in
their timing so that combustion will not occur in all the combustion chambers
at the
same time, but will occur at regular intervals.
In yet another embodiment, it is envisaged that a number of rotors may be
located on
the same shaft, with each rotor interacting with a corresponding rotor as a
rotor set.
Each of these rotor sets may be in synchronisation with each other, or may be
phased so that they are out of synchronisation with each other.
