Spring Washer Axial Play Compensation in High Pressure Pump

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-pressure pumps experience axial play due to manufacturing tolerances, leading to increased wear, noise, and risk of spring plate failure, as well as affecting pumping tolerances.

Innovation Solution

An elastically deformable spring plate with a radially inner support ring featuring raised and lowered areas at angular distances from radially extending webs, allowing for axial preload and compensation of axial play, reducing noise and overload on the spring plate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a rigid spring plate is used to maintain structural stability, then manufacturing precision is improved, but axial play compensation capability deteriorates

Engineering Contradiction:
Improvepumping tolerancesVSAvoidaxial play compensation
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The spring plate transitions from a rigid structure to a dynamically adaptable one through the circular waviness feature. The waviness allows the plate to elastically deform and adapt to axial play variations while maintaining operational stability, resolving the contradiction between rigidity and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the geometric parameters of the spring plate by introducing circular waviness with specific amplitude and wavelength characteristics. This parameter modification enables the plate to exhibit both structural stability and axial play compensation capability simultaneously.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If manufacturing tolerances are reduced to eliminate axial play, then component wear is reduced, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvecomponent wear resistanceVSAvoidmanufacturing precision requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention converts the harmful effect of axial play into a beneficial feature by designing the spring plate with circular waviness that actively compensates for the play. Instead of trying to eliminate axial play through tighter tolerances, the design embraces it and uses the waviness to maintain consistent contact and reduce wear.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

By modifying the geometric parameters of the spring plate (introducing circular waviness), the invention achieves wear reduction without requiring reduced manufacturing tolerances. The waviness parameters are optimized to provide continuous contact despite axial play.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the spring plate is made more rigid to prevent breaking, then structural strength is improved, but noise from component impact increases

Engineering Contradiction:
Improvespring plate durabilityVSAvoidnoise
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The circular waviness transforms the rigid spring plate into a dynamic structure that can absorb impact energy through elastic deformation. This dynamic behavior reduces the transmission of impact forces that cause noise while maintaining the overall structural strength of the plate.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The circular waviness acts as a pre-designed cushioning mechanism that absorbs impact energy before it can propagate through the system. The elastic deformation of the wavy structure provides beforehand cushioning against the high-speed impacts that generate noise.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 spring plate effectively compensates for axial play, reducing wear and noise, and enhancing the filling efficiency of the high-pressure pump by providing a 'soft' cushioning effect during piston movement reversals.

Implementation Method 1

the spring plate has a circular waviness, which enables the compensation of a production-related axial play... the spring plate is elastically deformable

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The return spring, which is supported on the spring plate, keeps the plunger and pump piston in contact with the drive shaft

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2702270B1Spring washer for a plunger assembly of a high pressure pump and high pressure pump
Publication Date: 2017.07.05 ROBERT BOSCH GMBH
  • EP2702270B1 patent drawingFigure 1
  • EP2702270B1 patent drawingFigure 2a~2b
  • EP2702270B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a spring washer for a plunger assembly (2) of a high pressure pump in a fuel injection system, wherein the spring washer (1) particularly has a bending punched part and a central recess (3) for receiving a pump piston (4). According to the invention, the spring washer (1) furthermore has at least two crescent-shaped recesses (5) arranged around the central recess (3) that form one support ring (6) located radially inside and one support ring (7) radially outside, which support rings are connected to one another by substantially radial webs (8), wherein the support ring (6) located radially inside has regions (9, 10), which are raised and lowered relative to a plane (E) and which are each arranged at an angle spacing to the substantially radial webs (8). The invention further relates to a high pressure pump for a fuel injection system having such a spring washer (1).