Fuel Pumping Unit Pressure Relief and Stator Cooling
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Solution Overview
Problem
Existing fuel pumping units for internal combustion engines face issues with high stress on seals and resilient rings due to increased pressure, leading to inefficiencies and fuel deterioration caused by heating within the pump's second containing chamber.
Innovation Solution
A pumping unit design that incorporates a connection duct to recirculate fuel from the high-pressure chamber back to the intake duct, reducing pressure within the chamber and alleviating stress on seals and resilient rings, while using a brushless permanent-magnet electric motor to enhance cooling and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gear pump is used to feed fuel from storage tank to piston pump, then the fuel delivery function is improved, but the pressure increase inside the second containing chamber causes high stress on seals and resilient rings
Solution Approach 1:
The pump body is divided into two separate containing chambers: a first containing chamber for housing the gearings and a second containing chamber for housing the stator. This segmentation isolates the high-pressure fuel region from the motor compartment, preventing fuel from pressurizing the second chamber and reducing stress on seals and resilient rings while maintaining fuel delivery functionality.
2Stress or pressure
If the fuel pressure increases inside the second containing chamber, then the fuel delivery capability is improved, but the heating of fuel inside the second containing chamber prevents cooling of the stator
Solution Approach 1:
The pump body is divided into two separate containing chambers: a first containing chamber for housing the gearings and a second containing chamber for housing the stator. This segmentation isolates the high-pressure fuel region from the motor compartment, preventing fuel from pressurizing the second chamber and reducing stress on seals and resilient rings while maintaining fuel delivery functionality.
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 design reduces stress on seals and resilient rings, allows for the use of lightweight and low-cost materials, improves cooling of the stator, and enhances the electrical efficiency of the motor, thereby preventing fuel deterioration and maintaining pump performance.
Implementation Method 1
an outer resilient ring arranged between the cover and the electric motor so as to axially lock the said motor to the cup-shaped body
Implementation Method 2
The cover is arranged in contact with the side wall and is connected in a fluid-tight manner to the cup-shaped body by means of an annular seal arranged in between
Implementation Method 3
Following rotation of the rotor and the internal gearing about the corresponding axes of rotation, each variable-volume chamber is connected hydraulically in succession firstly to an intake duct for drawing the fuel into the gear pump and then to a delivery duct for feeding the fuel to the piston pump
Implementation Method 4
an electric motor of the brushless permanent-magnet type
Data Source
AI summary
A pumping unit for feeding fuel, preferably diesel fuel, to an internal combustion engine has a pre-feed pump (3), which feeds the fuel to a high-pressure pump (2), is connected to a fuel storage chamber by means of an intake duct (49) and is provided with two gearings (40, 42) engaging with each other and made to rotate by an electric motor (37), a stator (38) of which is housed inside a containing chamber (48) formed in a pump body (32) of the pre-feed pump (3) and hydraulically connected to the intake duct (49).