Cup-Shaped Membrane Milk Pump Reduces Friction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hand-operated breast pumps experience fatigue due to friction between the piston and the pump wall, as well as mechanical and thermal deformations, leading to increased pumping effort and discomfort, especially with designs that require precise alignment and are prone to wear, which is not effectively addressed by existing technologies.
Innovation Solution
A milk pump design featuring a cup-shaped membrane with a disk-shaped guide part that allows for a large stroke and minimal friction, using a two-armed lever for actuation and a dome-shaped cross-section to reduce friction and facilitate operation, eliminating the need for a separate retraction device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a piston is used with a straight longitudinal axis in a cubic capacity, then the pump structure is simple, but friction between the piston seal and the wall increases, leading to hand fatigue
Solution Approach 1:
The patent applies curvature by using an arcuate displacement chamber instead of a straight cubic capacity, and an arcuate piston movement path that envelops the chamber. This curved design reduces friction between the piston seal and wall by allowing smoother movement, directly addressing the hand fatigue problem while maintaining structural simplicity
2Ease of operation
If an arcuate displacement is used to reduce friction, then hand fatigue is reduced, but manufacturing precision requirements increase due to alignment tolerances
Solution Approach 1:
The arcuate design with enveloping surface geometry provides inherent alignment tolerance. The curved paths of both the displacement chamber and piston movement are designed to work together, where minor deviations from perfect alignment do not significantly impact performance, thus reducing manufacturing precision requirements compared to straight-line designs
3Volume of moving object
If a membrane is moved against its inherent elasticity to achieve short stroke, then pump size is reduced, but the membrane becomes sensitive to tension and tears easily
Solution Approach 1:
The arcuate piston movement follows a curved path that works with the natural elasticity of the membrane rather than against it. This enveloping curved trajectory allows the membrane to flex smoothly during its stroke, reducing tension stress and preventing tears while maintaining a compact pump design
4Device complexity
If the membrane is attached to the inner surface of the horn in the relaxed state, then the structure is compact, but the membrane sticks to the surface during operation, increasing friction and fatigue
Solution Approach 1:
The arcuate movement path ensures that the membrane is continuously moved away from the inner surface of the horn during operation. The curved trajectory creates sufficient clearance between the membrane and the horn surface, preventing sticking and reducing friction while maintaining structural compactness
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 significantly reduces fatigue by minimizing friction and allowing for efficient and easy pumping with reduced effort, as the membrane can move freely within the pump chamber without causing friction, enhancing the suction effect and ease of use.
Implementation Method 1
an approximately cup-shaped elastic membrane (10) which is inserted into the cubic capacity (9) and fastened at its edge (11)
Data Source
Figure 1~2
Figure 1A
Figure 2A
AI summary
A hand-pump unit (1) has a suction unit and a lifting chamber (9) surrounded by a wall (9'), connected to a breast attachment piece (3) and extending along a longitudinal axis. An operating device, especially a manual device, moves the suction unit to and fro. A membrane (10) moves against the wall inside the lifting chamber and has a section crosswise to the lifting chamber.