Pinned Roller Bearing Pin Alignment to Reduce Axial Load

Solution Overview

Problem

Conventional pinned roller bearings in mechanical pumps amplify axial loads on the crankshaft due to imprecise alignment of pins, leading to corkscrew deformation and pump failure, as a result of manufacturing processes like cold riveting and welding which cause pin placement inaccuracies.

Innovation Solution

A pinned roller bearing design featuring pins with threaded and unthreaded ends, where the threaded end is engaged with support rings using hot riveting, and shouldered configurations for precise countersinking, ensuring pins remain parallel and perpendicular to the races, reducing skewing and warping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If cold riveting or welding processes are used to affix pins to support rings, then the bearing assembly can be manufactured, but the pins become misaligned and create axial load on the crankshaft

Engineering Contradiction:

Improvemanufacturing processVSAvoidpin alignment precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The pin is pre-threaded during manufacturing, allowing for precise alignment to be established before the final assembly step. This preliminary precision alignment prevents misalignment issues that would otherwise occur during the riveting or welding process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the traditional mechanical fastening methods (cold riveting or welding) with a threaded engagement system. This substitution allows for precise alignment to be maintained while still achieving secure attachment of the pin to the support rings.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If pins are precisely aligned perpendicular to races, then axial load on crankshaft is reduced, but manufacturing complexity increases

Engineering Contradiction:

Improvereduction of axial loadVSAvoidpin configuration complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The pin is divided into distinct functional segments: a threaded portion for secure attachment, a smooth portion for rotation within the roller, and a shouldered portion for alignment. This segmentation allows each portion to perform its specific function optimally while maintaining overall simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the pin have different geometric properties tailored to their specific functions. The threaded portion provides secure attachment, the smooth portion enables rotation, and the shouldered portion ensures precise alignment. This local differentiation of properties achieves precise alignment without requiring complex overall design.

Inventive Principle:

Principle #3Local quality

3Strength

If threaded portion extends through support ring, then secure attachment is achieved, but pin placement precision is compromised

Engineering Contradiction:

Improvepin attachment strengthVSAvoidpin placement precision

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The pin is pre-threaded during manufacturing, allowing for precise alignment to be established before the final assembly step. This preliminary precision alignment prevents misalignment issues that would otherwise occur during the riveting or welding process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the traditional mechanical fastening methods (cold riveting or welding) with a threaded engagement system. This substitution allows for precise alignment to be maintained while still achieving secure attachment of the pin to the support rings.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11015644B2Pinned cylindrical roller bearing

Publication Date: 2021.05.25 ENGINEERED BEARING TECH INC

AI summary

A pinned roller bearing assembly having a plurality of pinned rollers, wherein each of the pins has a first threaded end received in a threaded aperture of a first support ring, and a second unthreaded and shouldered end received in a countersunk and unthreaded aperture of a second support ring. Each end of each pin extends through its respective support ring and is rivetingly domed outside the support ring to secure its position and configuration. The pinned roller bearings and support rings are disposed within an outer and inner race.