RU2570295C2 - Low-thrust rocket engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to low-thrust rocket engines. Claimed engine with thrust control comprises the combustion chamber, mixing head with channels and fuel component feed control devices and fuel components distribution nozzles. Note here that said fuel component feed control devices incorporated the piezoelectric actuators. Engine thrust characteristics are controlled by built-in supply sources connected in electric circuit of every piezoelectric actuator. Note also the supply sources incorporate the voltage controller.

EFFECT: higher reliability, control over fuel component feed performed by one device.

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Description

The present invention relates to small thrust rocket engines, with thrust control for use in orientation systems, correction, launching the main engine of spacecraft, providing a soft landing for descent vehicles.

Known liquid rocket engine according to the patent of the Russian Federation No. 2315194, in which the function of the thrust regulator is performed by two flow regulators, which are controlled by servo throttles. The throttling element of the servo throttle of the flow regulator in the first component is connected to the pressure line of the pump of the first component after the nozzle nozzle and acts as a flow regulator. The throttling element of the servo throttle of the flow regulator for the second component is connected to the pressure line of the pump of the second component after the servo throttle, which performs the function of the regulator of the ratio of the flow of the component.

The rocket engine control circuit proposed in this patent is characterized by the complexity of the design of flow controllers, which include servo throttles. The throttling elements are connected to a regenerative cooling system and a turbopump. The use of this control scheme for rocket thrusters is impossible due to the lack of regenerative cooling and the lack of direct connection between the operation of the turbopump unit and the operation of the thruster.

Known rocket thruster according to US patent No. 3.203.446, in which the regulation of engine thrust is carried out by changing the flow rate of the component and the ratio of components. The small thrust rocket engine comprises a combustion chamber with an expanding nozzle that is connected to a mixing head on which two valves and two flow regulators are installed. The mechanism of simultaneous control of flow regulators allows the movement of control needles by the same amount or by values in a certain ratio. Needles of regulators are connected by rods through hinges with lever drive.

Known throttle rocket engine according to US patent No. 3.372.543, which contains the head of the combustion chamber with centrifugal nozzles with internal bias and an adjustable cross-sectional area of the inlet openings. The nozzle cross-section is regulated by petals connected by rods to control hydraulic cylinders. The required ratio of the fuel components is pre-set by adjusting screeds.

A common drawback of the patents presented is the implementation of the engine regulation function using two different devices: a valve and a fuel component flow regulator connected in series with it, as well as the need to use a complex articulated lever drive or a separate hydraulic drive to control the fuel component flow regulators.

Known rocket engine with adjustable thrust according to US patent No. 3.421.700, taken as a prototype of the invention, containing a combustion chamber, a mixing head with channels and devices for supplying and controlling the flow of fuel components, as well as nozzles for distributing fuel components. Each fuel component is supplied from the valve to the flow regulator, consisting of a Venturi tube and a control gap. Both flow controllers are controlled simultaneously. The regulation of the flow area of the Venturi tube and the control gap is achieved by the corresponding movement of the hollow profiled needle. The movement of the needle is carried out by a drive from an end-face electric motor, and the degree of movement of the needle is controlled by changing the voltage supplied to the electric motor. The needle travel is controlled by a servo-mechanism controlled by a change in the inductance of the electromagnetic valve.

The disadvantage of this design of the thruster, with thrust regulation, is the complexity of organizing the function of supplying and regulating the flow of fuel components, in which the control needle is moved from a special electric drive, and the degree of movement of the needle depends on the drive voltage regulator. In this case, the magnitude of the needle stroke is controlled by a servo mechanism controlled by a change in the inductance of the electromagnetic valve actuator. There is no filter in the design of the flow regulator to capture particles that are formed from friction during the operation of the electric drive and the servomechanism, which can lead to clogging of the flow part of the fuel supply channel and disruption of the engine regulation function. The engine traction control system, consisting of a large number of complex mechanisms, cannot guarantee high reliability, and also complicates the design of the propulsion system and increases its dimensions and weight.

The implementation in production of such a rocket engine regulation system is associated with high costs for the production, testing and operation of the product, which reduce the profitability of the production of space technology.

The objective of the present invention is to provide a reliable thruster with traction control that is simple in design and cost-effective in production by using such a control principle that allows you to perform the function of supplying fuel components to the engine, controlling its mass flow rate and controlling the ratio of fuel components in one device.

The solution to this problem is based on the use of a device operating on the physical principle of the “inverse piezoelectric effect”, which implements the property of the piezoelectric element to change the amplitude of movement depending on the magnitude of the electric voltage supplied to the piezoelectric element.

To this end, in the well-known small thrust rocket engine containing a combustion chamber, a mixing head with channels and devices for supplying and regulating the flow of fuel components, as well as nozzles for distributing fuel components, devices for supplying and controlling the flow of each fuel component have a piezoelectric drive, and for control of traction characteristics of the engine is equipped with power sources that are built into the electrical circuit of each piezoelectric drive, while the power sources have voltage regulators.

The variable thrust rocket engine is shown in FIG. 1 and FIG. 2. In FIG. 1 shows a general view of a rocket engine; FIG. 2 shows a device for feeding and controlling the flow rate of a fuel component.

The small thrust rocket engine contains a combustion chamber 1, which is connected to the mixing head 2. Channels 3 and 4 are made on the mixing head and two devices are installed for supplying and controlling the flow of fuel components 5 and 6, which communicate with channels 7 and 8, respectively.

A device for supplying and controlling the flow of fuel components comprises a housing 9; piezoelectric actuator 10, stem 11, O-ring 12, cup spring 13, to preload the piezoelectric actuator, travel multiplier 14 (cannot be opened), valve 15, seat 16 and return spring 17. The piezoelectric actuator is electrically connected to the source by wires 18 and 19 nutrition 20.

A centrifugal nozzle 21 for supplying fuel to the combustion chamber and a nozzle 22 for supplying an oxidizing agent are installed in the mixing head. The engine is equipped with a heat shield 23. An expanding nozzle 24 is made on the combustion chamber.

Power supplies 20 are equipped with voltage regulators 25.

The thrust rocket engine operates as follows. The oxidizing agent "O" is fed through channel 3, and the fuel "G" is fed through channel 4, made in the mixing head 2, and enter the input arrow "A" of the device for supplying and controlling the flow of fuel components 5 and 6, respectively. Devices for feeding and regulating the flow of fuel components 5 and 6 normally closed type. When applying voltage from the power supply 20 through the wires 18 and 19 to the piezoelectric actuator 10, in accordance with the principle of the “inverse piezoelectric effect”, a directional change in the type of crystal lattice of the piezoelectric element 10 and, as a result, linear movement of its end face occurs. The piezoelectric actuator 10 is installed in a rigid casing 9 with preliminary preload by a disk spring 13 and has the ability to move only towards the valve 15. The movement of the piezoelectric element through the rod 11 is transmitted to the stroke multiplier 14 (not disclosed). The multiplier increases the movement of the piezoelectric actuator in proportion to the gear ratio. The movement of the piezoelectric element increased in the stroke multiplier 14 is transmitted to the valve 15, which overcomes the force of the spring 17 and the pressure of the working fluid departs from the seat 16. When the valve 15 is open, the fuel components “G” or “O” fall into the volume behind the valve in the direction of the arrow “B” and then through channels 7 and 8, respectively, are fed to the nozzles 21 and 22.

The piezoelectric actuator 10 is protected from the effects of the fuel components "O" or "G" by the sealing ring 12.

The fuel components "G" and "O" from the nozzles 21 and 22, respectively, fall into the combustion chamber for mixture formation, during which one of the components forms a protective film. When the fuel components “O” or “G” are connected in the combustion chamber 1, a chemical reaction of combustion occurs, with an increase in temperature and pressure, and when the combustion products expire through the expanding nozzle 24, a jet engine thrust is created.

Protection from external influences of a thrust rocket engine is provided by a protective shield 23.

The thrust of a rocket engine depends, inter alia, on the flow rate of the fuel components involved in the combustion reaction. The control of the supply of fuel components occurs when voltage is supplied from the power source 20 to the piezoelectric actuator 10 in the device for supplying and regulating the flow of fuel components 5 and 6. The flow rate of each fuel component is controlled by changing the displacement of the piezoelectric actuator 10 and the associated valve 15. The value the movement of the valve 15 depends on the magnitude of the voltage supplied to the piezoelectric actuator 10. To implement the function of regulating the flow of the working fluid, the power supply The 20 of the piezoelectric actuator 10 is equipped with a voltage regulator 25, which sets the change in the magnitude of the voltage and accordingly changes the amplitude of the movement of the piezoelectric actuator 10. In proportion to the change in the voltage supplied to the piezoelectric actuator 10, the stroke of the valve 15, the flow area and the mass flow rate of the working fluid change accordingly. It should be noted that in this design of the device for feeding and regulating the flow of fuel components 5 and 6, the depth of regulation of the flow parameters depends on the magnitude of the valve stroke change, the transformation coefficient in the multiplier 14. The nominal value of the ratio of the fuel components “O” and “G” is adjusted during manufacture engine, and the regulation of the ratio of the fuel components "O" and "G" is carried out within the necessary limits due to the separate regulation of the voltage supplied by the voltage regulators 25 for each device for feeding and regulating the consumption of fuel components 5 and 6 separately. In this case, due to the varying degree of regulation of the flow rate of each component of the fuel, their ratio in the chemical reaction of combustion changes and, accordingly, the energy parameters of the thrust rocket engine.

The technical result of the present invention of a thruster, with throttle control, is to increase reliability by simplifying the design by using an integrated device for feeding and regulating the flow of the working fluid having a piezoelectric drive and performing the functions of controlling the flow and regulating the flow when the fuel components are fed into the engine, as well as regulating the ratio of the components of the fuel "O" and "G" due to the separate regulation of each device.

The next technical result of this invention is to increase the profitability of production of a small thrust rocket engine with thrust regulation by eliminating complex control mechanisms from the design and, accordingly, reducing the cost of their production, testing and operation.

Claims (1)

A small thrust rocket engine containing a combustion chamber, a mixing head with channels and devices for supplying and controlling the flow of fuel components, as well as nozzles for distributing fuel components, characterized in that the devices for supplying and controlling the flow of each fuel component have a piezoelectric drive, and for control of traction characteristics of the engine is equipped with power sources that are built into the electrical circuit of each piezoelectric drive, while the power sources have voltage regulators.

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