Piston Fuel Pump Seal with Axial Bumps
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Solution Overview
Problem
Existing piston fuel pumps require complex manufacturing processes and high-cost materials due to the need for precise piston bushing fits and tolerance management, which increases production complexity and costs.
Innovation Solution
A piston fuel pump design featuring a seal with axial bumps on the circumference of the pump piston, allowing for reduced bearing area and deformation compensation, eliminating the need for precise piston bushing fits and enabling the use of less expensive materials while maintaining high-pressure fuel compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a piston bushing with small sealing gap and close fit is used, then sealing performance is improved, but manufacturing complexity and cost increase
Solution Approach 1:
A seal element is introduced as an intermediary component between the piston and cylinder bore. This seal element carries the sealing function, allowing the piston bushing to be manufactured with relaxed tolerances using simpler processes such as casting or basic machining, while still achieving reliable sealing through the dedicated seal component
Solution Approach 2:
The sealing function is extracted from the piston bushing structure itself and transferred to a separate seal element. This allows the bushing to focus on mechanical support and guidance functions with simplified manufacturing, while the seal element专门 handles sealing requirements
2Reliability
If a piston bushing with small sealing gap and close fit is used, then sealing performance is improved, but production cost increases
Solution Approach 1:
The seal element can be designed as a simpler, potentially replaceable component that is easier and cheaper to manufacture than a precision piston bushing. This allows the use of less expensive materials and manufacturing processes for the seal while maintaining overall system reliability
Solution Approach 2:
The seal element serves as a cost-effective intermediary that provides the necessary sealing function without requiring expensive precision manufacturing of the piston bushing, thereby reducing overall production costs
3Reliability
If a piston bushing with certain length is used to support and seal, then sealing capability is improved, but transverse force absorption increases device complexity
Solution Approach 1:
The function of absorbing transverse forces is extracted from the sealing requirement. The seal element is designed to handle sealing while separate structural features of the piston or bushing handle transverse load bearing, allowing each component to be optimized for its specific function
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 reduces production costs, improves piston dynamics, and maintains high-pressure fuel compression capabilities without deformation, while accommodating component and assembly tolerances through axial prestress and deformation of the bumps.
Implementation Method 1
The compression of the fuel takes place, in particular, in said working space, in particular by way of an axial movement of the pump piston which reduces the size of the working space. In particular, a compression of the fuel in the working space takes place to a high pressure level, for example to from 100 bar to 600 bar.
Implementation Method 2
a seal which is arranged on the circumference of the pump piston and for its part has at least one bump which points in an axial direction... the at least one bump is particularly preferably configured as a locally convexly configured region in an otherwise concavely configured surrounding of the seal... accommodating component and assembly tolerances through axial prestress and deformation of the bumps
Data Source
AI summary
A piston fuel pump for an internal combustion engine includes a pump cylinder and a pump piston, which can be axially displaced in the pump cylinder. The piston fuel pump also includes a seal which is arranged on the periphery of the pump piston. The seal has at least one bump pointing in the axial direction, and the seal axially covers the at least one bump.