Tappet Anti-Rotation Device for Injection Pump Cam Follower

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Solution Overview

Problem

Existing cam followers in injection pumps for motor vehicles often experience improper collaboration between the roller and cam due to incorrect angular orientation, leading to malfunction, and existing anti-rotation solutions complicate assembly and increase the number of subcomponents.

Innovation Solution

A mechanical system with a tappet, support element, and roller that integrates an anti-rotation device, allowing for accurate orientation and simplified assembly by forming the anti-rotation device within the support element, which is fixed to the body through local deformations, eliminating the need for additional parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an additional anti-rotation part is fixed to the tappet, then the anti-rotation function is provided, but the number of subcomponents increases and assembly becomes more complex

Engineering Contradiction:
Improveanti-rotation functionVSAvoidnumber of subcomponents
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the anti-rotation function with the pin support function into a single integrated support element. The support element includes both the pin bores and an anti-rotation device that prevents rotation of the entire support element relative to the tappet, eliminating the need for separate anti-rotation components while maintaining both functions

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The support element is designed to perform multiple functions simultaneously: it supports the pin for roller rotation, provides structural connection between roller and tappet, and includes an integrated anti-rotation device that prevents unwanted rotation. This multi-functional design reduces component count while ensuring reliable operation

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If an additional anti-rotation part is fixed to the tappet, then the anti-rotation function is provided, but the assembly process becomes longer and more complex

Engineering Contradiction:
Improveanti-rotation functionVSAvoidassembly time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

By integrating the anti-rotation device into the pin support element as a single component, the patent reduces the number of assembly steps. The support element with integrated anti-rotation feature is installed in one operation, eliminating the need to separately install and secure additional anti-rotation parts

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If the anti-rotation device is integrally formed with the support element, then the design is simplified and assembly is easier, but the support element structure becomes more complex

Engineering Contradiction:
Improveassembly simplicityVSAvoidsupport element structure
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The support element is designed as a distinct component separate from both the tappet body and the roller assembly. This segmentation allows the anti-rotation device to be integrally formed with the support element structure, simplifying assembly while managing complexity through modular component design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The anti-rotation device is integrally formed with the pin support element, combining what could be separate components into a single manufactured part. This integration simplifies assembly operations while the modular support element design keeps overall system complexity manageable

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 integrated anti-rotation device ensures correct orientation of the cam follower, preventing rotation malfunctions while simplifying the design and assembly process, and effectively supporting the pin without additional components, enhancing the mechanical system's functionality and reliability.

Implementation Method 1

the support element being fixed to the body by local deformations of the body

Methodology Applied
Scientific EffectLocal deformations: Deformation

Data Source

PatentEP2853699B1Tappet, injection pump and valve actuator comprising such a tappet and manufacturing method for such a tappet
Publication Date: 2016.05.25 AB SKF SKF PATENT DEPARTMENT
  • EP2853699B1 patent drawingFigure 1~2
  • EP2853699B1 patent drawingFigure 3~4
  • EP2853699B1 patent drawingFigure 5~6

AI summary

The invention relates to a mechanical system (1), comprising a tappet (10) including a body (11), a support element (20) defining two bores (258) centered on a first axis (X1), a pin (30) comprising two opposite ends each adapted to be fitted in one of the two bores (258), and a roller element (40) positioned between the two bores (258) along the first axis (X1) and movable in rotation relative to the pin (30) around the first axis (X1). According to the invention, the support element (20) is distinct from the body (11) and fixed thereto, and the support element (20) also comprises at least one antirotation device (24) integrally formed thereto. The invention also relates to an injection pump and a valve actuator comprising such a mechanical system (1). The invention also relates to a manufacturing method.