Fuel Pump Annular Gap and One-Way Valve Design
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Solution Overview
Problem
Internal combustion piston engines require high-pressure fuel pumps that prevent the mixing of fuel and lubrication oil, a challenge not adequately addressed by existing technologies, which often lead to inefficiencies and potential leakage in common rail systems.
Innovation Solution
A fuel pump design incorporating one-way valves in the vent and discharge flow paths, an annular gap that circumscribes the first space section, and a bushing attached to the pump body, which together prevent fuel from entering the lubrication system while maintaining high-pressure fuel delivery above 200 MPa.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the pump uses a single chamber design for both fuel pumping and lubrication, then the device complexity is reduced, but fuel and lubrication oil mixing occurs
Solution Approach 1:
The pump chamber is divided into a first space section and a second space section separated by a partition. The first space section handles fuel pumping while the second space section handles lubrication, preventing mixing while maintaining a relatively simple overall pump structure.
2Productivity
If the pump operates at high pressure above 200 MPa, then the fuel delivery performance is improved, but the risk of fuel leakage into the lubrication system increases
Solution Approach 1:
A one-way valve is introduced as an intermediary element in the communication path between the first and second space sections. This valve allows controlled interaction between the high-pressure fuel side and lubrication side while preventing harmful fuel leakage into the lubrication system.
3Device complexity
If the pump piston is directly braced on the drive shaft, then the device complexity is reduced, but the pump piston cannot compensate for positional deviations
Solution Approach 1:
The support element's position along the drive shaft is made adjustable rather than fixed. This allows the support element to be positioned optimally to brace the pump piston, compensating for manufacturing tolerances and operational deviations while maintaining a simple bracing structure.
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 effectively minimizes fuel-lubrication oil mixing, enhancing the pump's performance and reliability by ensuring efficient fuel transfer and preventing leakage into the lubrication system, thus improving the overall efficiency of the high-pressure fuel pump.
Implementation Method 1
The vent flow path (36) is provided with a one-way valve (40) which allows gas escape from the second space section (30'') but prevents fuel from entering the lubrication system
Implementation Method 2
The discharge flow path (38) is provided with a one-way valve (42) which allows fuel discharge from the second space section (30'') but prevents backflow
Implementation Method 3
an annular gap (47) in the second space section (30'') which circumscribes the first space section (30')
Implementation Method 4
a piston member (28) arranged into a cylindrical space (30) in a reciprocable manner... The piston member (28) reciprocates in the space (30) provided for the piston member (28) and pumps the fuel
Implementation Method 5
The wall of the first space section (30') and the wall of the piston member (28) are arranged against each other providing a sealing gap (34) therebetween
Implementation Method 6
a lubrication system configured to supply lubrication oil to the cylindrical space (30)
Data Source
Figure 1
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AI summary
Invention relates to a fuel pump (10) for supplying fuel to an internal combustion piston engine, comprising a body (18) and a cylindrical space (30) in the body having a central axis (32), a piston member (28) arranged to reciprocate in the cylindrical space (30), the piston member is provided with a sleeve member (46) having a closed end arranged to the second space section (30'') such that an annular space is provided between the sleeve member (46) and the piston member (28), where the pump comprises an annular gap circumscribing the piston member (28) at least partially, and where the sleeve member is arranged to ex-tend into the annular gap where a third space section (60) is arranged bordered by the sleeve member (46), and where a lubrication oil supply channel (62) and a lubrication oil discharge channel (64) are connected to the third space section (60).