Rotary internal combustion engine

A prime mover which is constituted by a compressor casing having a combustion gas inlet, a compressor rotor rotatably mounted in the compressor casing and having at least one vane movable radially of the rotor and resiliently sealingly engaged with the inside surface of the wall of the compressor casing for forming a compression chamber therein, a prime mover casing adjacent the compressor casing and having an exhaust outlet therein and a spark plug mounted thereon, a prime mover rotor rotatably mounted in the prime mover casing and having at least one vane movable radially of the rotor and resiliently sealingly engaged with the inside surface of the wall of the prime mover casing for forming a combustion chamber therein, the rotors being connected for causing them to rotate together, and a passage opened and closed by the rotation of the rotors for passing compressed combustion gas from the compressor casing to the prime mover casing at predetermined intervals for being ignited by the spark plug.

BACKGROUND OF THE INVENTION AND PRIOR ART 
The rotary type prime mover of the present invention is an improvement of 
the prime mover which is the subject of U.S. application Ser. No. 236,289, 
filed Feb. 19, 1981, which in turn is a continuation-in-part of U.S. 
application Ser. No. 37,333, now abandoned. 
In the device of said application, however, each cycle of induction, 
compression, firing and exhaust is performed in one casing. That is to 
say, the opening or closing of the casing, or the induction or exhaustion 
of air is performed in one casing. 
But there are some disadvantages in the device of said application. Both 
the induction valve and the exhaust valve of the said device tend to wear 
out and also tend to get out of order so they are not opened or closed at 
an exact time. Thus, it is difficult for the internal combustion engine of 
the said application to maintain air-tightness and to perform its 
operation efficiently. In order to overcome such disadvantages, the 
present inventor made a further study of this engine, which resulted in 
the present invention. 
OBJECTS AND BRIEF SUMMARY OF THE INVENTION 
A first object of the invention is to provide a prime mover in the form of 
a rotary engine which can maintain a high degree of air-tightness during 
both the compression cycle and the firing cycle so as to obtain a highly 
efficient machine. 
A second object of the invention is to provide such an engine in which 
automatic induction and exhaustion are achieved by the rotation of rotors 
in a compressor casing and a prime mover casing so as to make it possible 
to dispense with the induction and an exhaust valves. 
A third object is to simplify the construction of the engine, which also 
reduces the possibility of the engine getting out of order. 
A fourth object is to provide a machine which is relatively inexpensive. 
To this end, the present invention provides a gas compressor casing which 
performs induction and compression, and a prime mover casing which 
performs firing and exhaust. A gas passage is provided between the two 
casings to connect with each other. 
Thus, by providing a gas intake at the front part of a compressor chamber 
where induction and compression are performed and an exhaust port at the 
back part of the prime mover casing where the firing and exhaust are 
performed, the rotation of the rotor in each casing performs an automatic 
induction and exhaust. Thus, this engine need not be provided with an 
induction valve or an exhaust valve, and it is easy for this engine to 
maintain air-tightness during both compression and firing cycles. 
Therefore, the present engine is very efficient, inexpensive, and has a 
simple construction.

In the drawings, the numeral 1 designates a compressor casing. The lower 
part of the inner wall is circular in cross-section while the upper part 
is approximately elliptical with its short axis arranged in the vertical 
direction and is smoothly connected to the said circular portion. The 
numeral 2 designates a prime mover casing which is above the said 
compressor casing and connected thereto to form a unitary engine casing. 
The upper part of the inner wall is elliptical in cross-section with the 
short axis of the ellipse arranged vertically and the lower part is 
circular and is smoothly connected to the said elliptical part. As shown 
in FIG. 1A, a cylindrical compressor rotor 3 for compressing combustion 
gas has several sections with different diameters. A prime mover rotor 4 
is provided which is similar in shape to the rotor 3, and is rotated by 
the firing of the combustion gas. A rotor 36 connects the compressor rotor 
with the prime mover rotor 4 on the same shaft. Shafts 37 and 38 on the 
ends of the rotor 36 and shafts 7 and 8 on the ends of the rotor 4 are 
supported by end walls 9 and 10 of the casings 1 and 2 and the rotors 3 
and 4 to rotate in close contact with the circular cross-section parts of 
the casings 1 and 2 respectively. Vanes 39 and 12 having shape as shown in 
FIG 1B are radially slidable in a groove 38 extending through the center 
of the rotor 36 and a plate spring 14 is positioned between the vanes 
urging them radially outwardly. Vanes 39 are resiliently urged by the 
plate springs 14 to cause the outer ends to contact the elliptical 
cross-section parts of the casings 1 and 2 respectively, and maintain the 
air-tightness of a combustion chamber 18 in which firing takes place and 
from which the products of combustion are exhausted, and of a compression 
chamber 19 respectively, dividing the insides of the casings 1 and 2 into 
two parts respectively. 
The numerals 20 and 21 designate intermediate walls provided adjacent the 
opposite ends of casings 1 and 2 which define vane guide chambers 22 and 
23 between them and the end walls 9 and 10 at the opposite ends of the 
combustion chamber 18 and the compression chamber 19 respectively. Vane 
guide chambers 22 and 23 have inner walls with cross-sectional shapes 
which are approximately elliptical similar to the upper parts of the 
casings 1 and 2. Compressed gas receiving grooves 26 are provided on 
diametrically opposite parts at the middle. Gas for combustion is drawn 
into compressor casing 1 through a gas induction port 27 just past, in the 
direction of rotation, the gas passage 42 and is compressed by the vanes 
39 in the compression chamber during the rotation of the rotor 36, and as 
shown in FIG. 8, only when a groove 43 is aligned with recess 40 can the 
gas compressed in the compressor chamber 19 in the casing 1 pass through 
the corresponding hole 42, and be forcibly introduced into the 
corresponding compressed gas delivery recess 26. Then the rotor 36 rotates 
and the spark plug 28 installed in the operating chamber 18 in the casing 
2 ignites the compressed gas in the compressed gas delivery recess 26 
immediately after it is closed at the compressor chamber end as shown in 
FIG. 7. The ignition leads to the explosion of the compressed gas in the 
said groove 26, which in turn pushes the vanes 39 to forcibly rotate the 
rotor 36. With the rotation of the rotor 4, the expanded gas in the 
combustion chamber 18 is discharged through the exhaust port 29 provided 
in the operating chamber 18 just ahead of, in the direction of rotation of 
the rotor, the position of the motor as shown in FIG. 6. 
A plurality of air holes 30 are provided in the vanes 39 in the vane guide 
chambers 22 and 23. Said holes 30 facilitate the rotation of the vanes 39 
in the vane guide chambers 22 and 23. 
FIG. 12 shows the equations for the elliptical cross-section parts of the 
casings 1 and 2 and the vane guide and the length of the short axis be 
"2b", and the distance between the center of the elliptical part and the 
center of the rotor be "c". 
Then a shape of the ellipse will be given by 
EQU (b.sup.2 -c.sup.2)x.sup.2 +b.sup.2 y.sup.2 =b.sup.4 (1) 
But according to the present invention, the circumference of the elliptical 
part should be made smaller in the radial direction towards the center of 
the rotor. In other words, if the value .delta. in the following Equation 
(2) is substracted from the diametrical dimensions of the ellipse of 
Equation (1), the vanes will ideally rotate in close contact with the 
inner surfaces of the elliptical cross-section parts of the casings 1 and 
2 without moving toward or away from each other. 
##EQU1## 
where ".theta." is an angle in radians between the vanes and the "x" axis. 
If the vane guide chambers 22 and 23 are made smaller, the equation 
therefor uses the dimensions shown in FIG. 12. Here, "e" is radius of the 
rotor 36 in the vane guide chambers 22 and 23. Then, when assembling the 
machine with such dimensions, and in order to insert the vanes 39 already 
inserted in the groove 38 of the rotor 36 into the holes in the 
intermediate walls 20 and 21, the relation between "e" and the radius of 
the holes in the intermediate walls a is represented by the following 
equation: 
EQU d=e+c (3) 
Also, the approximate equation for the elliptical part of the vane guide 
chambers 22 and 23 can be approximated, in the same manner as stated 
before, as shown in FIG. 12, by the following equation: 
##EQU2## 
In this case, however, according to the present invention the curvature of 
the inner wall of the vane guide chambers 22 and 23 should be corrected 
somewhat manually or by calculation based on Equations 1 and 2. 
Cooling passages 31 are provided in the casing 2 and the rotor 36 and cool 
water or oil is pumped therethrough. A flywheel 32 is provided on one 
shaft 37 of the rotor 4, and facilitates a smooth rotation of the rotor 
36. The numeral 33 designates a base upon which the engine is installed. 
The numeral 40 designates a recess in the central wall 35 as shown in FIG. 
10. Gas introducing holes 42 are provided in the rotor and extend parallel 
with the vane grooves 38 and extend from compression gas receiving grooves 
43, provided in the surface of the rotor portion 4 on diametrically 
opposite sides thereof and opposed to the recess 40, to gas delivery 
recesses provided in the surface of the rotor portion 3 at diametrically 
opposite sides and opening into the casing 2. 
As shown in FIG. 8, only when a groove 43 is aligned with recess 40 can the 
gas compressed in the compressor chamber 19 in the casing 1 pass through 
the corresponding hole 42, and be forcibly introduced into the 
corresponding compressed gas delivery recess 26. Then the rotor 36 rotates 
and the spark plug 28 installed in the operating chamber 18 in the casing 
2 ignites the compressed gas in the compressed gas delivery recess 26 
immediately after it is closed at the compressor chamber end as shown in 
FIG. 12. The ignition leads to the expolsion of the compressed gas in the 
said groove 26, which in turn pushes the vanes 39 to forcibly rotate the 
rotor 36. With the rotation of the rotor 4, the expanded gas in the 
combustion chamber 18 is discharged through the exhaust port 29 provided 
in the operating chamber 18 just ahead of, in the direction of rotation of 
the rotor, the position of the rotor as shown in FIG. 6. 
FIGS. 13 and 14A-14D show another embodiment in which a compressor rotor 
portion 3' and a prime mover rotor portion 4' are arranged in series with 
each other. Compressed gas delivery recesses 26' are provided in the 
surface of the prime rotor portion 4' at diametrically opposite positions. 
The gas holes extend from the gas delivery recesses 26' parallel with vane 
groove 38. The intake openings 43 of the gas holes 42 are provided at 
diametrically opposite points on the surface of the compressive rotor 
portion 3' and open in opposite directions respectively. Thus, the gas 
holes 42 connect the combustion chamber 18' with the compressor chamber 
19'. 
The operation of this embodiment is as follows: gas "h" as compressed 
casing 1' in FIGS. 14A is forced into a compressed gas delivery recess 26' 
in FIG. 14C through the gas hole 42. The compressed gas "h" is ignited by 
the spark plug 28 and then exploded and expanded. The exploded and 
expanded gas "h" forcibly pushes the vane 39, as shown in FIG. 14D, which 
in turn rotates the rotor 36. 
With the rotation of the rotor 36, the expanded gas "h" in the combustion 
chamber 18 is exhausted through the exhaust port 29. Meanwhile, with the 
rotation of the rotor 36, a combustion gas, which is introduced from a gas 
delivery duct 27 into the compression chamber 19 in FIG. 14A, is 
compressed as shown in FIG. 14B, and then the rotor returns to the state 
as is shown in FIG. 14A to complete one cycle. 
Unlike the embodiment as shown in FIGS. 7 and 8, this embodiment has no 
recess 40 to open into the recess 43 of the gas hole 42. Besides, in this 
embodiment the construction of the device can be made simpler, and it is 
easier for the device to maintain air-tightness. What is more, if the 
compression ratio is raised and if the spark plug 28 is replaced with a 
fuel spray nozzle, the device of this embodiment can be used as a crude 
petroleum combustion engine. 
As shown in FIGS. 9 and 10, end seals 44 and 44 are provided at both ends 
of the rotor 36 and the vanes 39, and also a seal spring 45 and an under 
seal 46 is provided in the lower circular cross-section part of the casing 
34. The air-tightness can thus be further improved in any of the 
embodiments. 
The present invention has the construction as described hereinabove. As 
compared with a conventional reciprocating internal combustion engine, the 
present engine has neither an inducction valve nor an exhaust valve, can 
easily maintain air-tightness, and is small in size and light in weight. 
Besides, as practically all of the explosive power of the gas burned in 
the present engine can be converted into rotational power, it can operate 
at high pressure and is efficient, and thus a great amount of saving in 
fuel is possible. The present engine does not swing much in operation. 
Because it is simple in construction, the present engine is inexpensive, 
and will not easily get out of order.