Anti-Rotation Plug for Engine Roller Lifter

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing hydraulic lash adjusting tappets with roller followers in internal combustion engine valvetrains face challenges in preventing rotation around their longitudinal axis, which can lead to inefficiencies and increased noise due to oil leakage when inverted during assembly.

Innovation Solution

The implementation of an anti-rotation plug with a staking mechanism that creates an interference fit with the roller lifter body, using a cylindrical plug body with radial walls for staking, and configurations such as a relief or undercut to accommodate material deformation, ensuring the roller lifter remains stationary and preventing oil leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the roller lifter is allowed to rotate freely during assembly, then ease of assembly is improved, but oil leakage occurs when inverted leading to noise and reduced reliability

Engineering Contradiction:

Improveease of assemblyVSAvoidprevention of oil leakage

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The anti-rotation plug incorporates a relief or undercut feature that allows controlled material deformation during the staking process. This dynamic approach enables the plug to transition from a loose fit during assembly to a locked position after staking, preventing oil leakage while maintaining ease of assembly.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent replaces complex mechanical anti-rotation mechanisms with a simple staking process. The anti-rotation plug uses radial walls that deform radially outward during staking to create an interference fit, substituting elaborate locking mechanisms with a straightforward mechanical deformation approach.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Stability of the object's composition

If the anti-rotation plug uses a tight interference fit, then prevention of rotation is improved, but difficulty of assembly increases

Engineering Contradiction:

Improveanti-rotation stabilityVSAvoidease of assembly

Core Design Contradiction:

Stability of the object's compositionVSEase of operation

Solution Approach 1:

The anti-rotation plug is designed with a relief or undercut feature beforehand, allowing material to deform radially outward during staking. This preliminary design enables the plug to be inserted easily in a loose state and then locked in place through controlled deformation, avoiding difficult assembly while ensuring anti-rotation stability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The staking process changes the physical parameters of the anti-rotation plug by deforming the material radially outward. This parameter change transforms the plug from a loose-fit state during assembly to a tight interference fit after staking, resolving the contradiction between ease of assembly and anti-rotation stability.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the roller lifter body is deformed during staking, then secure locking of the plug is improved, but manufacturing precision may be affected

Engineering Contradiction:

Improvelocking reliabilityVSAvoiddimensional accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The relief or undercut feature is localized to specific areas of the roller lifter body where material deformation is desired during staking. This local quality approach allows controlled deformation in specific regions while maintaining manufacturing precision in other critical areas, ensuring locking reliability without compromising overall dimensional accuracy.

Inventive Principle:

Principle #3Local quality

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 anti-rotation plug effectively inhibits rotation of the roller lifter about its longitudinal axis, maintaining operational efficiency and preventing oil leakage during inverted assembly, thereby reducing noise and ensuring reliable engine performance.

Implementation Method 1

an anti-rotation plug with a staking mechanism that creates an interference fit with the roller lifter body

Methodology Applied

Scientific EffectInterference fit:

Implementation Method 2

configurations such as a relief or undercut to accommodate material deformation

Methodology Applied

Scientific EffectMaterial deformation: Deformation

Implementation Method 3

radial walls for staking

Methodology Applied

Scientific EffectRadial deformation: Deformation

Data Source

PatentUS10690016B2Engine valve lifter having anti-rotation plug

Publication Date: 2020.06.23 EATON CORP

AI summary

An engine roller lifter for use in a leak-valvetrain of an internal combustion engine includes a body, a roller and an anti-rotation plug. The body includes an outer peripheral surface configured for sliding movement in a bore provided in the engine. The bore is supplied oil by an oil passage communicating therewith. The body defines an opening. The roller bearing is rotatably mounted to the body and is configured for rolling contact with an engine camshaft. The anti-rotation plug is received at the opening and has a plug body including an anti-rotation protrusion that extends radially beyond an outer peripheral surface of the plug body. The anti-rotation plug can be staked into the opening of the body.