Piston Pump With Tapered Bore Reduces Dead Space
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Solution Overview
Problem
Piston pumps used in vehicle brake systems have inefficiencies due to large dimensions and high construction costs, primarily because of their design which includes solid pistons and firmly anchored inlet valves, leading to suboptimal dead volume and efficiency.
Innovation Solution
The piston pump design features a pressure chamber with two areas of different inner diameters, allowing for a larger piston diameter and reduced dead space, achieved by a tapering shoulder connecting these areas, which also simplifies manufacturing and assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a constant diameter cylinder bore is used, then the structural simplicity is maintained, but the dead space is large and efficiency is reduced
Solution Approach 1:
The cylinder bore is designed with different diameters in different axial regions. The first region has a larger diameter to accommodate the piston stroke, while the second region has a smaller diameter to reduce dead space. This local variation in geometry optimizes both efficiency and volume utilization without compromising structural simplicity.
2Productivity
If a larger piston diameter is used, then the pumping capacity is increased, but the external dimensions and dead space increase
Solution Approach 1:
The piston diameter is optimized for the first region of the cylinder where it performs the pumping function, while the second region uses a smaller diameter to minimize dead space. This allows the piston to have a larger effective diameter for capacity without increasing the overall external dimensions of the pump housing.
3Volume of stationary object
If the cylinder bore diameter is reduced in the second area, then the dead space is reduced, but the manufacturing complexity increases
Solution Approach 1:
The transition between the two cylinder regions is achieved through a tapering shoulder with a constant pitch angle, which can be manufactured using standard machining operations. This approach reduces dead space while maintaining manufacturing simplicity through the use of conventional forming and machining processes.
4Productivity
If the piston stroke length is increased, then the pumping capacity is increased, but the overall pump length increases
Solution Approach 1:
The pump capacity is increased by optimizing the piston diameter in the first region rather than increasing the stroke length. This allows the pump to achieve higher capacity while maintaining a compact axial length, as the capacity increase comes from the radial dimension (diameter) rather than the axial dimension (stroke length).
Data Source
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AI summary
The invention relates to a piston pump which is used to guide a fluid and which comprises a cylinder (8), a piston (2) which is displacably arranged in the cylinder (8), a return element (17) for the piston (2) and a drive in order to displace the piston (2) in the cylinder (8). The cylinder (8) comprises a first area (11) having a first internal diameter (Dl) and a second area (12) having a second internal diameter (D2). The first internal diameter (Dl) is greater than the second internal diameter (D2).