A turbocompound engine having a stratified charge or diesel cycle rotary internal combustion engine, with a first output shaft and a turbine engine with a second output shaft. The first and second output shafts are coupled together so that the shafts rotate in synchronism with each other and provide a rotary output from the turbocompound engine. A valve variably directs air inducted into the engine between the turbine engine and internal combustion engine in dependence upon engine operating conditions.

BACKGROUND OF THE INVENTION 
I. Field of the Invention 
The present invention relates generally to engines and, more particularly, 
to a turbocompound engine having a stratified charge or diesel cycle 
rotary internal combustion engine, compounded with a turbine engine. 
II. Description of the Prior Art 
There have been a number of previously known compound engines having two 
diverse engine types which are coupled together to provide a common 
output. Such compound engines enjoy many advantages in certain 
applications. For example, in some operating conditions, one of the 
diverse engine types is particularly efficient during certain operating 
conditions while, conversely, the other engine type enjoys certain 
efficiencies during different operating conditions. For this reason, one 
engine type complements the other engine type to provide overall engine 
efficiencies over the range of operating conditions of the compounded 
engine. 
To Applicant's best knowledge, however, there has never previously been a 
turbo diesel rotary internal combustion engine which has been successfully 
compounded with a throttleable turbine engine. Furthermore, such a 
compounded engine would enjoy numerous advantages in weight and size in 
critical applications, such as aircraft engines. 
SUMMARY OF THE PRESENT INVENTION 
The present invention provides a turbocompound stratified charge or diesel 
cycle rotary internal combustion engine and turbine engine which is 
compact in weight and size and yet highly efficient in operation over a 
wide range of engine operating conditions. 
In brief, the turbocompound engine of the present invention comprises a 
stratified charge or diesel cycle rotary internal combustion engine. The 
internal combustion engine includes a housing and a combustion chamber 
contained within the housing having an inlet and an outlet. A rotary 
piston is rotatably mounted within the combustion chamber and, when 
rotatably driven by engine combustion, rotatably drives a first output 
shaft. 
The compound engine further comprises a turbine engine having a turbine 
compressor, a turbine impeller and a turbine or second output shaft which 
mechanically connects the compressor and turbine impeller together. A 
combustion chamber or combustor is fluidly connected in series between the 
compressor output and the turbine impeller input and has a source of fuel 
also connected to it. In operation, upon rotation of the turbine shaft, 
the compressor provides compressed air to the combustor and this 
compressed air, together with fuel injected into the combustor, is 
ignited. The resulting combustion products from the combustor exhaust past 
the turbine impeller to rotatably drive the impeller and, thus, rotatably 
drive the compressor via the turbine shaft. 
The combustion chamber inlet for the internal combustion engine is fluidly 
connected to a diffuser passageway extending between the turbine 
compressor and the combustion engine so that the turbine compressor 
provides compressed air not only to the turbine combustor but also the 
internal engine combustion chamber. In addition, the outlet or exhaust 
from the internal engine combustion chamber is also fluidly connected to 
the combustor. Consequently, the energy from the internal combustion 
engine exhaust is at least partially recovered by the turbine engine. 
The turbine shaft and internal combustion engine output shaft are 
mechanically or hydrostatically connected together so that these two 
output shafts rotate in synchronism with each other. Since the turbine 
output shaft necessarily rotates at much higher speeds than internal 
combustion engine output shaft, a speed reduction gearing arrangement, 
such as a planetary gear arrangement, is interposed between the output 
shafts in order to match their rotational speeds. A continuously variable 
transmission (CVT) is used to mechanically or hydrostatically connect the 
turbine and internal combustion output shafts together and the CVT is in 
turn used to drive a rotary output from the turbocompound engine, such as 
a turboprop. This can provide relatively fixed output torque and speed 
over a range of engine operating conditions. 
In the preferred form of the invention, a throttle is contained in the 
diffuser passageway immediately upstream from the combustor. This throttle 
is movable between a closed and an open position. In its closed position, 
the throttle diverts most of the compressed air flow through the diffuser 
assembly to the internal combustion engine so that the internal combustion 
engine provides a majority of the work output from the turbocompound 
engine. Conversely, when the throttle is in its fully open position, most 
of the compressed air flow in the diffuser passageway passes into the 
combustor, rather than into the combustion chamber for the internal 
combustion engine. In this case most of the work output from the 
turbocompound engine is provided by the turbine engine. 
Furthermore, the throttle can be variably opened between its fully closed 
and fully open position to vary the proportionate amount of work output 
from the compound engine provided by the internal and turbine engines, 
respectively. 
In practice, the throttle is substantially closed at low engine output 
speeds which are more efficiently handled by the internal combustion 
engine, and open at higher engine operating speeds at which the turbine 
engine operates more efficiently than the internal combustion engine.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION 
With reference to the drawing, a preferred embodiment of the turbocompound 
engine 10 of the present invention is thereshown and comprises both a 
turbine engine 12 and an internal combustion engine 14. Both the turbine 
engine 12 and the internal combustion engine 14 will both be described in 
greater detail. 
The turbine engine 12 comprises a compressor 16 and a turbine impeller 18 
which are coaxial but spaced apart from each other. A turbine output shaft 
20 drivingly connects the turbine compressor 16 to the turbine impeller 18 
so that the impeller 18 and compressor 16 rotate in unison with each 
other. 
A diffuser passageway 22 fluidly connects a pressurized output 24 from the 
compressor 16 to an inlet 26 of a combustor 28 for the turbine engine 12. 
A source of fuel 30 is also fluidly connected with the combustor 28 while 
conventional means (not shown) are used to ignite a fuel air mixture in 
the combustor 28. 
A turbine nozzle passageway 32 in turn fluidly connects an outlet 34 from 
the combustor 28 to an inlet to the turbine impeller 18. Preferably, a 
variable nozzle assembly 36 is disposed in the nozzle passageway 32 in 
order to vary its aerodynamic characteristics. 
The diffused passageway 22, combustor 28 and nozzle passageway 32 together 
form a fluid passage means between the compressor 16 and the turbine 18. 
In the well known fashion, the compressor 16 when rotatably driven, 
provides pressurized air to the combustor 28 through the diffuser 
passageway 22. Fuel from the fuel supply 30 is then also introduced into 
the combustion 28 and ignited. The resulting hot and expanding combustion 
products from the combustor 28 then exhaust through the nozzle passageway 
32 and past the turbine impeller 18 thus rotatably driving the turbine 
impeller 18. These exhaust products ultimately exit out through the 
exhaust 38 thus providing additional thrust for the turbine engine 12. 
The internal combustion engine 14 comprises a housing or engine block 40 
containing at least one preferably two combustion chambers 42. Each 
combustion chamber 42, moreover, is designed to receive one rotary piston 
44, such as a Wankel rotor. 
Each rotary piston 44 is mechanically connected to a sleeve output shaft 46 
which is coaxial with the turbine output shaft 20. Furthermore, as shown 
in the drawing, preferably the turbine output shaft 20 extends entirely 
through the sleeve output shaft 46 so that the turbine compressor 16 is 
situated on one end of the sleeve shaft 46 while the turbine impeller 18 
is situated adjacent the opposite end of the sleeve shaft 46. 
Alternatively, the turbine impeller 18 and turbine compressor 16 may be 
adjacent and the turbine output shaft 20 may extend coaxially with the 
rotary sleeve output shaft 46. 
An inlet passageway 47 fluidly connects each combustion chamber 42 with the 
diffuser passageway 22. Consequently, highly compressed heated air is 
provided by the compressor 16 to the combustion chambers 42. Diesel or jet 
fuel from a fuel source 48 is also provided to each combustion chamber 42. 
Each combustion chamber 42 further includes an exhaust outlet 50 which is 
fluidly connected by an exhaust passageway 52 to the turbine engine 
combustor 28. 
In operation, the turbine compressor 16 supplies highly compressed and 
heated air to the combustion chambers 42 through the diffuser passageway 
22 and combustion chamber inlet passageways 47. Simultaneously, fuel from 
the diesel or jet fuel source 48 is provided to each combustion chamber 42 
and self ignites or is ignited in sequence by multiple spark plugs 
positioned in chamber 42 during the compression cycle. Stratified or self 
ignition of the diesel fuel 48 within the combustion chambers 42 rotatably 
drives the sleeve shaft 46 in the well known fashion. 
The sleeve output shaft 46 is mechanically connected to a CVT 56 by a gear 
ring assembly 58. Similarly, the turbine output shaft 20 is mechanically 
connected to the CVT 56 by a planetary gear arrangement 60 (illustrated 
only diagrammatically) which may be of any conventional construction. The 
planetary gear arrangement 60 reduces the rotational speed transmitted by 
the turbine shaft 20 to the CVT 56 in order to match the rotational speed 
of the sleeve shaft 46. Typically, a speed reduction of between 6:1 and 
15:1 for planetary gear arrangement 60 is required. 
The CVT 56 may be of either mechanical or hydraulic construction and 
mechanically or preferably hydrostatically couples the sleeve output shaft 
46 and turbine output shaft 20 together so that they rotate in synchronism 
with each other. The CVT 56, in turn, rotatably drives an output drive 62 
to drive a turboprop 64 or the like. 
A throttle 66 is disposed in the diffuser passageway 22 between the 
combustor 28 and the internal combustion engine inlet passageways 47. The 
throttle 66 is movable between a closed position, illustrated in solid 
line, and an open position, illustrated in phantom line. In its closed 
position, the throttle 66 diverts most of the compressed air flow through 
the diffuser passageway 22 into the combustion chambers 42 of the internal 
combustion engine 14. Conversely, in its open position, the throttle 66 
allows most of the compressed air flow through the diffuser passageway 22 
to directly enter the combustor 28 and bypass the combustion chambers 42. 
In practice this throttle 66 is controlled in its position by a 
microprocessor or central processor unit or electronic control module 
which senses engine parameters, provides closed loop feedback controlling 
air flow and fuel flow in order to control both load sharing between the 
two power units and to control final output speed and torque to predesired 
levels. 
In practice, the turbocompound engine of the present invention achieves 
many of the advantages over the previously engines. In particular, the 
throttle 66 allows the ratio of the power output between the turbine and 
internal combustion engines to be varied in accordance with engine 
operating conditions. As such, efficient engine operation is achieved over 
a wide range of different operating conditions. 
A further advantage of Applicant's invention is that the exhaust from the 
internal combustion engine 14 is provided as an inlet to the combustor 28 
of a turbine engine. This allows the heat energy from the exhaust of the 
internal combustion engine 14 to be at least partially recovered by the 
turbine engine. This in turn results in a more efficient operation of the 
engine. 
A still further advantage of applicant's invention is that the 
turbocompound engine is relatively compact and lightweight in 
construction. This is particularly advantageous for weight and size 
critical applications, such as aircraft engines. 
Having described my invention, many modifications thereto will become 
apparent to those skilled in the art to which it pertains without 
deviation from the spirit of the invention as defined by the scope of the 
appended claims.