JPS58167865A - Output power conversible composite engine - Google Patents

Abstract

PURPOSE:To make it possible to carry out the conversion between jet propelling power and shaft output power, by providing a pitch control means for variably controlling the pitch of fan blades and a nozzle passage opening means for variably controlling the opened passage sectional areas of power turbine nozzle passages. CONSTITUTION:A pitch control mechanism 15 variably controls the pitch of the blades 16 of a fan 2, and a nozzle passage opening control mechanism 19 controls the cross sectional areas of opened nozzle passages between the vanes 20 of a power turbine 7. In the pitch control mechanism 15 shaft output power is increased or decreased by changing the pitch, and in the nozzle passage opening control mechanism 19 absorption outout power of a power turbine is decreased or increased by widening or narrowing the opened passages between vanes 20 so that the engine is controlled with an optimum conversion efficiency between both types of turbofan and turboshaft engines, thereby the transient operation between propelling power and shaft power is smoothly and stably carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas turbine engine used as a prime mover for helicopters, VTOL aircraft, etc., and particularly to a compound engine whose output is convertible.

The basic structure of this type of composite engine is:
The configuration of turbofan engines (including ducted fan engines) widely installed in fixed-wing aircraft, and the configuration of turboshaft engines used in some fixed-wing aircraft and some rotary-wing aircraft. It has a structure in which the image compositions of
This will be explained with reference to the block.

(a) Turbofan engine (Figure 1) This engine is an engine that generates jet thrust and operates.
However, the configuration is that the air intake port → fan is formed along the axis from the front of the engine, and after that, it is branched into two systems, the fan air system and the gas generator system, and the fan air system is A fan air nozzle is formed, -Ji
, In the gas generator system, compressor → combustion chamber → IE m
Machine drive turbine → power turbine → exhaust nozzle is formed.

The transmission shaft between the drive turbine and the compressor and the transmission shaft between the power turbine and the fan are double shafts, with the former serving as an outer shaft and the latter serving as an inner shaft.

When the engine is operating, the Φ air sucked into the engine from the air intake port is accelerated by the fan, and most of it is sent to the RB compressor, while a part of it is
Air is ejected through the entire nozzle, which generates jet thrust in the engine.

On the other hand, high-pressure air pressurized by the compressor enters the combustion chamber.
By mixing with the supplied fuel and combusting it, it is transformed into a high-temperature, high-pressure gas stream.

This gas flow first drives a driving turbine, and the gas flow whose pressure is lowered in the turbine is lowered. After driving a power turbine, it is ejected into the atmosphere through an exhaust nozzle. This generates jet thrust in the engine.

(b) Turboshaft engine (Figure 2) This engine is an engine that generates shaft power, and the shaft power is used as the drive source for the rotor blades and the propulsion propeller. It is normal to be

The structure is, in order from the front of the engine, air intake → compressor → combustion chamber → drive turbine, and the output shaft is mechanically branched off from the power turbine via a gear.

During operation of this engine, most of the energy of the combustion gas entering the power turbine is mechanically extracted to the output shaft as shaft power, and a portion is converted into thrust by the exhaust nozzle.

The configuration of the block shown in the figure (indicated by solid lines) is for the case where the rotor is driven by shaft power, and if the shaft power is used to drive the propulsion propeller, that is, in the case of a turboprop engine, As indicated by the dashed line in the figure, the structure is such that the projecting shaft extends forward from the axis of the power turbine and projects from the center of the air intake port.

To begin with, if we look at the VTOLiwo that have been used in the past, and the various power systems used during elevation and forward movement, there are models that are driven by shaft power like ordinary helicopters, and barrier machines made in the UK. There are lift-jet models that use only the thrust of the turbofan engine to ascend, descend, or fly forward by changing the jet direction, but technically, there is a lift-jet model that uses only the thrust of the turbofan engine to move up and down or forward flight. A variety of power systems have been considered that use different types of power and shaft power, and research and development on such VTOL machines has been actively conducted in recent years.

Here, when looking at both the hovering efficiency during vertical movement and the propulsion efficiency during forward movement in a vTOL aircraft, by the above-mentioned motive power system, as shown in the table in Figure 3, in the above-mentioned helicopter system, hovering efficiency Although the efficiency is extremely good, the propulsion efficiency is extremely poor, and the lift jet method has completely contradictory characteristics.

As a power system that moderates these biased characteristics,
A stopped rotor wing system (also known as a fixed rotor wing system or an In addition, during horizontal flight, the rotor is fixed and the thrust of the same engine is used, and its power efficiency is excellent in both hovering and propulsion efficiency, as shown in the table in Figure 3. .

The present invention has been made in order to obtain a power source suitable for the above-mentioned stopped rotor wing system and similar power systems for compound helicopters. A convertible compound engine that has both the functions of an engine and a turboshaft engine, and that can smoothly and stably convert between the double-edged phase U of jet thrust and shaft power. It is about providing.

The present invention will now be described based on an illustrated embodiment.

As shown in FIGS. 4 and 5, the composite engine of the embodiment includes, in order from the front of the engine, an air intake 1, a fan 2, a fan air nozzle 3, a compressor 4, a combustion chamber 5, a drive turbine 6, A nozzle turbine 7, an output shaft 8, and an exhaust nozzle 9 are formed.

Thus, when the fan 2 and the power turbine 7 are coupled together as one body via the inner shaft 10, the compressor 4 and the drive turbine 6 are coupled together as one body via the outer shaft 11. In addition, the output shaft 8 is connected to the clutch 1 as a connection/disconnection control 1114.
2 and a direction conversion gear 1:3, the combustion chamber 4 includes a fuel injection nozzle 11.
is attached.

Furthermore, the three control mechanisms described in F are attached to key points of the engine.

(a) Pitch control mechanism 15 This mechanism 15 operates to variably control the pitch of the blades 16 of the fan 2, and its structure includes an l=T variable that is widely used in various propellers. Pitch structure is used.

(b) Fan air flow rate control mechanism 17 This structure 17 controls the opening and closing of the fan air nozzle;3, and its structure includes a shutter 18 that can be freely controlled to open and close.
is used.

(e) /Zuzzle opening control f1wt19 This mechanism 19 is disposed on the outer periphery of the power turbine 17, and operates to variably control the cross-sectional area of the nozzle opening between the vanes 20 of the turbine 7. The structure used is a structure widely used for various vane type nozzles.

For example, as shown in FIG. 6, the drive arm 21 of each vane 20 may be actuated in the circumferential direction by an actuator 24 via an interlocking rod 22 and an interlocking link 23.

The above-mentioned controllers 1112, 15, 17, and 19 of the composite engine of the embodiment configured in this way are incorporated into the operating system of the aircraft body on which the engine is mounted and are automatically controlled, but qualitatively. is a 6 part □・
□fa) Effects when clutch 12 is engaged (1) Hitch control machine [In 15, the pitch is increased (
By increasing or decreasing the thrust and shaft output, the increase or decrease in thrust and shaft output is not a temporary effect, but by matching the amount of internal air in the engine for each type, the shaft output can be increased as a secondary result. It is possible to increase (decrease).

(2) In the fan air flow rate controller $17, by opening the shutter 18 (solid line) (or closing it/dot line), the fan air flow can be used as a jet or the amount of air to the gas generator can be increased to improve the shaft output. be able to.

(3) In nozzle opening control @@19, by widening (or narrowing) the opening between the vanes 20,
The absorption power in the power turbine can be reduced (in the case of jet propulsion) or increased (in the case of turboshaft) to best control the conversion efficiency of each type.

(b) Only active thrust is generated when clutch 12 is disengaged, ie, the engine operates as a turbofan engine. In this case, fan air flow control mechanism 1
The shutter 18 of No. 7 is set to the solid line position, and the nozzle opening controller l
At l119, the open circuit is set in the direction of widening.

Since the engine of the example is operated in this manner, it is possible to always operate the output at the best efficiency for both types of engines, and the transition operation between thrust and shaft power is smooth and stable. It can be done by

In the configuration of the embodiment described above, the shaft power is taken out from the rear end of the inner shaft 10 for the purpose of driving the rotor, but if the purpose is to drive the propulsion propeller instead, the second As shown by the chain line in the figure, the inner shaft may be extended forward as it is, and the clutch or reduction gear may be placed in the center of the air intake port 1.

As described above, according to the output convertible compound engine according to the present invention, the structure is configured to combine the image configurations of a turbofan engine and a turboshaft engine, and furthermore, a fan and a turbofan engine are combined. For each power turbine,
Since the pitch control means and the nozzle opening control means are provided, the efficiency of the engine's output operation is improved as described above (Fig. 3). is driven by a single engine, and has the effect of enabling both takeoff with high hovering efficiency and horizontal flight with high propulsion efficiency, and as a result, the lift jet aircraft shown in Figure 3 like,
``In addition to the immeasurable benefits to aircraft design, performance, and economy, such as not requiring engine thrust exceeding its own weight and eliminating the unnecessary dead weight of the ascent engine during horizontal flight, it is also useful for hovercraft other than aircraft. Other prime movers have the advantage of being widely applicable.

[Brief explanation of the drawing]

Figure 1 is a block diagram of the configuration of a turbofan jet engine, Figure 2 is a block diagram of the configuration of a mid-turboshaft engine, and Figure 3 is a convertible composite of characteristic forces for hovering and propulsion efficiency for each aircraft type. FIG. 5 is a schematic cross-sectional view of the engine, FIG. 5 is a block diagram of the structure of the compound engine, and FIG. 6 is an enlarged perspective view of the nozzle opening control mechanism. 2...Fan, 7...Power turbine, 15...
Pitch control mechanism, 16...Fan blade, 19...
- Nozzle opening control mechanism, 20... Vane forming a nozzle. Patent applicant Yukihiro Omori, Director of the Technology Research Headquarters, Defense Agency, Attorney Norimitsu Nishimura, Patent attorney

Claims (1)

[Claims] In a composite jet engine having a combination of a turbofan engine configuration and a turboshaft engine configuration, a pitch control means for variably controlling the pitch of fan blades, and a variable control means for variably controlling the open cross-sectional area of a nozzle passage of a power turbine. 1. A compound engine capable of converting output, characterized in that a nozzle opening control means is provided.