Internal Pocket Anti-Rotation for Low Profile Valve Lifter

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Solution Overview

Problem

Conventional roller lifters in internal combustion engines require a significant portion of their outer surface for anti-rotational features, leading to reduced sliding surface area, increased mass, and performance hampered by higher inertia forces and increased cost.

Innovation Solution

The solution involves using the inside of the roller lifter to provide orientation and prevent rotation, with a pocket and corresponding walls interacting to prevent rotation and a protuberance and groove system for proper orientation, reducing the need for an external anti-rotational guide.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the outer surface of the roller lifter is used for anti-rotational features, then the lifter can prevent rotation, but the sliding surface area is reduced

Engineering Contradiction:

Improveanti-rotational capabilityVSAvoidsliding surface area

Core Design Contradiction:

Stability of the object's compositionVSArea of moving object

Solution Approach 1:

Instead of using the outer surface of the lifter for anti-rotational features, the invention inverts the approach by using the inner surface of the lift guide to prevent rotation. The lift guide includes a flattened portion with a flat surface that contacts a corresponding flat surface on the lifter's inner surface, creating an anti-rotational mechanism that does not consume outer sliding surface area.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention moves the anti-rotational feature from the radial dimension (outer surface) to the axial dimension (inner surface contact). By positioning the flat surface on the lift guide's inner surface and having it contact the lifter's inner flat surface, the anti-rotational function is achieved in a different dimensional space, preserving the outer sliding surface.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Stability of the object's composition

If the outer surface of the roller lifter is used for anti-rotational features, then rotation is prevented, but the mass of the lifter increases

Engineering Contradiction:

Improveanti-rotational capabilityVSAvoidlifter mass

Core Design Contradiction:

Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

The invention extracts the anti-rotational function from the lifter body and relocates it to the lift guide. The lift guide includes the flattened portion with the flat surface that provides the anti-rotational contact, separating this function from the lifter's mass-critical outer surface and allowing the lifter to be optimized for minimal mass.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The flat surface on the lift guide acts as an intermediary element that provides the anti-rotational function without requiring mass addition to the lifter. This intermediary feature on the lift guide mediates the rotation prevention while keeping the lifter's mass minimal.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If the outer surface of the roller lifter is used for anti-rotational features, then proper orientation is achieved, but the inertia forces increase

Engineering Contradiction:

Improveorientation capabilityVSAvoidinertia forces

Core Design Contradiction:

Stability of the object's compositionVSForce

Solution Approach 1:

The invention inverts the orientation mechanism by using the inner surface of the lift guide rather than the outer surface of the lifter. The flattened portion with the flat surface on the lift guide contacts the lifter's inner flat surface, providing orientation without increasing the lifter's mass and thus reducing inertia forces.

Inventive Principle:

Principle #13The other way round (Inversion)

4Stability of the object's composition

If the outer surface of the roller lifter is used for anti-rotational features, then rotation is prevented, but the cost of the assembly increases

Engineering Contradiction:

Improveanti-rotational capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The invention extracts the anti-rotational feature from the expensive lifter component and places it on the lift guide, which is typically a less costly component. This extraction reduces the manufacturing cost by avoiding the need to machine or form anti-rotational features on the lifter's outer surface.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS7823555B2Low profile valve lifter assembly

Publication Date: 2010.11.02 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

The low profile valve lifter assembly has flats inside the bore of the outer housing and walls are formed and extended down from the plate of the guide such that the walls align with the flats of the bore to prevent rotation of the lifter with the guide. A groove and protuberance are provided in the flats and on the side wall of the guide in order to properly orient the lifter with the guide. The flats can be connected to form a pocket and the walls of the guide can be connected to form a sleeve that mates with the pocket.