Rocket Engine Electrical Power Transfer to Eliminate Shaft Seals
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Solution Overview
Problem
Mechanical wear and complexity of rotating shaft seals and bearings are prohibitive in smaller scale rocket engines, requiring high rotation speeds and complicating engine design and reliability.
Innovation Solution
Implement an electrical transmission system between the turbine and propellant pump, eliminating the need for mechanical shafts and seals, using hydrostatic and rolling element bearings for support, and allowing independent speed control of each unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a mechanical shaft connection is used between turbine and pump, then power transmission is achieved, but mechanical wear and seal complexity increase
Solution Approach 1:
The patent replaces the mechanical shaft connection with an electrical transmission system. The turbine drives a generator to produce electrical power, which then drives the pump motor. This substitution eliminates the need for mechanical shafts, seals, and bearing connections between the turbine and pump, thereby eliminating mechanical wear and improving reliability.
Solution Approach 2:
The patent introduces electrical energy as an intermediary between the turbine and pump. Instead of direct mechanical coupling, the turbine generates electrical power that is transmitted through electrical conductors to the pump motor. This intermediary approach allows independent optimization of the turbine and pump speeds and eliminates mechanical connection issues.
2Power
If rotating shaft seals are used to connect turbine and pump, then power transmission is enabled, but device complexity and leakage risk increase
Solution Approach 1:
The patent eliminates the mechanical shaft seal system by replacing it with an electrical transmission system. The generator and motor are coupled through electrical conductors rather than mechanical shafts, removing the need for rotary seals, dynamic seals, or packing seals that would otherwise be required to prevent propellant leakage.
Solution Approach 2:
The patent extracts and removes the sealing components (shaft seals, dynamic seals, packing seals) from the system entirely. By decoupling the turbine and pump through electrical transmission, the sealing requirements are eliminated, simplifying the overall device structure and reducing leakage risks.
3Stress or pressure
If high rotation speeds are used in small rocket engines, then required pressures are achieved, but mechanical wear and reliability decrease
Solution Approach 1:
The patent replaces the mechanical transmission system with an electrical one, allowing the pump to be driven at optimal speeds independent of the turbine speed. This eliminates the mechanical wear issues associated with high-speed shaft connections while maintaining the ability to achieve required pressures through proper pump design and electrical power transmission.
4Power
If a shared rotating shaft is used for turbine and pump, then power transmission is achieved, but maintenance complexity increases
Solution Approach 1:
The patent segments the power transmission system into independent electrical components. The generator and motor are separate units connected by electrical conductors, allowing each to be maintained and repaired independently. This eliminates the need to disassemble and maintain a shared rotating shaft assembly, simplifying maintenance procedures.
Solution Approach 2:
The patent replaces the shared mechanical shaft system with an electrical connection system. The generator and motor can be maintained separately without requiring disassembly of a common mechanical structure, thereby reducing maintenance complexity and improving ease of repair.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design simplifies mechanical complexity, improves reliability and reusability, enables independent speed control, and enhances propellant ratio control, leading to improved engine performance and thrust efficiency.
Implementation Method 1
heating of the propellant which is then used to drive a turbine placed in at least part of the subsequent propellant flow
Implementation Method 2
heating of the propellant which is then used to drive a turbine placed in at least part of the subsequent propellant flow
Implementation Method 3
a turbine generator unit arranged to receive a propellant flow through the turbine generator unit, and to generate electrical power
Implementation Method 4
a motor pump unit arranged to receive electrical power from the electrical transmission system and to use the received electrical power to pump a propellant flow
Implementation Method 5
the shaft within each unit may be supported, at least partially, using hydrostatic bearings integrated within each unit, and for which pressure is supplied using the working propellant fluid of the unit
Implementation Method 6
Electrical rotors of the turbine generator unit and motor pump unit may then be immersed or submerged in the working propellant fluid of each unit, which can be used for cooling of the generator or motor
Data Source
AI summary
There is disclosed a rocket engine arranged to deliver one or more propellants to a combustion chamber of the rocket engine for generating motive thrust. The rocket engine comprises an electrical transmission system, a turbine generator unit arranged to receive a propellant flow through the turbine generator unit and to generate electrical power and to pass the generated electrical power to the electrical transmission system, and a motor pump unit arranged to receive electrical power from the electrical transmission system and to use the received electrical power to pump a propellant flow though the motor pump unit.