Single-Blade Impeller Waterjet Propulsion System
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Solution Overview
Problem
Conventional waterjet propulsion systems require high drive power due to complex and maintenance-intensive shaft bushings, leading to inefficiencies, noise, pollution, and operational limitations in polluted or environmentally sensitive waters.
Innovation Solution
A waterjet propulsion system with a single-stage impeller having only one blade, connected to a low-power electric motor, eliminating the need for sealed shaft bushings and reducing friction and turbulence, allowing operation in polluted waters with low noise and no additional driving license required.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealed shaft bushing is used to guide the drive shaft, then the drive shaft can be guided and sealed, but the device complexity increases and maintenance becomes intensive
Solution Approach 1:
The patent removes the drive shaft entirely from the waterjet propulsion system. Instead of guiding and sealing a rotating drive shaft through the intake or outlet, the system uses a single-stage impeller with a single blade that is directly driven by the drive motor without requiring a penetrating shaft. This extraction of the drive shaft eliminates the need for complex sealed shaft bushings while maintaining reliable power transmission to the impeller.
2Reliability
If a sealed shaft bushing is used to guide the drive shaft, then the drive shaft can be guided, but friction increases and drive power requirement increases
Solution Approach 1:
The patent eliminates the drive shaft and its associated shaft bushing from the system. The single-stage impeller with a single blade is driven directly by the motor without requiring a rotating shaft that penetrates the housing. This removal of the shaft-bushing interface completely eliminates the friction losses that would otherwise occur at the shaft bushing, thereby reducing the drive power requirement.
3Power
If the drive shaft crosses the flow area, then the drive shaft can transmit rotational energy, but turbulence is caused and efficiency is reduced
Solution Approach 1:
The patent removes the drive shaft from the water flow path entirely. The single-stage impeller is driven without a shaft crossing the flow area, eliminating the source of turbulence and flow separation that a penetrating shaft would create. This maintains cleaner flow conditions and improves overall hydraulic efficiency while still transmitting rotational energy from the motor to the impeller through a non-intrusive connection.
4Power
If the drive shaft transmits rotational energy to surrounding water, then rotational energy is transmitted, but flow conditions deteriorate and drive shaft braking occurs
Solution Approach 1:
The patent eliminates the drive shaft that would otherwise be in contact with and transmit rotational energy to the surrounding water. By removing the shaft entirely and using a different power transmission approach, the system prevents the drive shaft from acting as a source of flow disturbance and braking forces, thereby improving operational reliability.
5Reliability
If grids are placed on intake openings to prevent clogging, then objects are prevented from entering, but flow resistance increases and turbulent swirls are created
Solution Approach 1:
The patent employs a single-stage impeller with a single blade design that inherently handles objects and debris more effectively than conventional multi-blade impellers. The simplified impeller geometry allows objects to pass through more easily without causing clogging, reducing or eliminating the need for protective grids at the intake opening. This segmentation approach maintains reliable operation while avoiding the flow resistance and turbulence that grids would create.
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
The system achieves low drive power requirements, enabling efficient and quiet operation in various water environments, including those with endangered fish stocks, without the need for high-power engines or special licenses, and is resistant to objects sucked in.
Implementation Method 1
an impeller region (3) adjoining the intake region (2), in which a single-stage impeller (4) is arranged
Implementation Method 2
The waterjet propulsion system has a hydrodynamically clean structure, whereby the required drive power is low
Implementation Method 3
a drive motor (6) which is connected at least indirectly to an impeller drive shaft (7) of the impeller (4)
Implementation Method 4
eliminating the need for sealed shaft bushings and reducing friction and turbulence
Implementation Method 5
reducing friction and turbulence
Data Source
AI summary
The invention relates to a waterjet propulsion system (1) for a watercraft, comprising an intake region (2), an impeller region (3) which adjoins the intake region and in which a one-stage impeller (4) is mounted, and an outlet nozzle (5) which adjoins the impeller region, the waterjet propulsion system having a drive motor (6) which is at least indirectly connected to an impeller driveshaft (7) of the impeller (4). According to the invention, the impeller has only one single blade (8).