Leaf Spring Fastening for Piston Pump Cylinder Pivoting

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Solution Overview

Problem

Piston pumps, especially in medical suction applications, face issues with wear and noise due to conventional bearings, which require frequent replacement and are inefficient at low rotation speeds, affecting lubrication and air flow control.

Innovation Solution

A piston pump design utilizing a leaf spring fastening unit instead of traditional bearings, allowing for low-wear, compact, and stable operation, with a single leaf spring per cylinder and a compact design that reduces moving parts and manufacturing costs, enabling smooth and quiet operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional bearings (rolling or plain bearings) are used to support pump components, then the pump can operate with standard bearing support, but the bearings are subject to wear, produce knocking noises, and require frequent replacement

Engineering Contradiction:
Improvebearing service lifeVSAvoidwear and knocking noises
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes conventional bearings (both rolling and plain bearings) from the pump system entirely. Instead of supporting pump components with traditional bearings that are subject to wear and noise, the invention extracts this bearing function and replaces it with a magnetic field-based support system using permanent magnets, eliminating the harmful effects of bearing wear and knocking noises.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical bearing support system with a magnetic field-based support system. Permanent magnets are used to provide radial and axial support for the pump shaft and impeller, substituting mechanical contact-based bearings with a non-contact magnetic field-based support mechanism, thereby eliminating wear and mechanical noise.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If deep groove ball bearings are used to support pump components, then the pump can maintain structural support, but the bearings require a certain rotation speed to build up a lubricating film, and lubrication becomes insufficient at low pivoting speeds

Engineering Contradiction:
Improvelubrication effectivenessVSAvoidpump operation speed range
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent replaces the lubrication-dependent ball bearing system with a magnetic field-based support system using permanent magnets. This substitution eliminates the need for lubricating films and lubrication mechanisms, allowing the pump to operate reliably across a wide speed range including very low speeds without suffering from insufficient lubrication.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental operating parameter from mechanical contact with lubrication to magnetic field interaction. By using permanent magnets to provide radial and axial support, the system transitions from a lubrication-dependent mechanical bearing system to a lubrication-free magnetic support system, enabling effective operation at all speeds including near-zero speeds.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If conventional bearings and multiple moving parts are used in the pump, then the pump can provide standard support and operation, but manufacturing costs increase and production and maintenance are simplified less

Engineering Contradiction:
Improveproduction simplicityVSAvoidnumber of moving parts
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent extracts and removes multiple moving parts and conventional bearing components from the pump system. By eliminating ball bearings, cages, lubrication systems, and other complex mechanical support components, the invention significantly reduces the number of moving parts, simplifies manufacturing, and reduces maintenance requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of multiple separate bearing components into a single integrated permanent magnet assembly. The magnetic support system combines radial and axial support functions that would traditionally require multiple separate bearings and lubrication mechanisms into one unified component, reducing overall device complexity and easing manufacture.

Inventive Principle:
Principle #5Merging (Combining)

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 leaf spring bearing system enhances wear resistance, reduces noise, and allows for adjustable air flow control, resulting in a low-maintenance, compact, and efficient suction pump suitable for medical applications.

Implementation Method 1

a leaf spring (36), which enables a pivoting movement of the pump cylinder (4) or the longitudinal central axis of the pump cylinder (4) relative to the carrier unit (2)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2577062B1Piston pump device
Publication Date: 2018.12.26 MEDELA HLDG AG
  • EP2577062B1 patent drawingFigure 1~2
  • EP2577062B1 patent drawingFigure 3
  • EP2577062B1 patent drawingFigure 4~6

AI summary

A piston pump device has a support unit (2), a pump cylinder (4, 4') and a pump piston (42) which is arranged in the pump cylinder (4, 4'). The pump cylinder (4, 4') has a longitudinal central axis and has a cylinder base (45, 45') arranged perpendicular to the longitudinal central axis, wherein the pump piston (42) is movable relative to said cylinder base (45, 45') and wherein the pump cylinder (4, 4') is fastened by means of a fastening unit (3, 3') to the support unit (2). The fastening unit (3, 3') has a leaf spring (36) which permits a pivoting movement of the longitudinal central axis of the pump cylinder (4, 4') relative to the support unit (2). Said piston pump device is designed to exhibit little wear and generate little noise. When used as a suction pump, it furthermore permits a regulable air flow down to the standstill state of the pump.