Planetary Pin Plug for Lubrication Flow and Deformation Control

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Solution Overview

Problem

Existing planetary bearing designs face challenges in ensuring sufficient lubrication flow, including high costs, complex assembly, risk of pin deformation, and debris issues from machining operations.

Innovation Solution

A pin assembly with a plug having an inlet and outlet recess aligned with the pin's bores, facilitating lubrication flow enhancement, constructed from a polymer material with a retention feature and cut-out for easy insertion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional lubrication delivery methods (hollow pins, cross drilled pins, pressed ball plugs) are used, then lubrication flow to planetary bearing is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvelubrication flowVSAvoidpin structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pin is divided into functional segments: a solid pin body for structural strength, a blind bore for plug retention, and aligned inlet/outlet bores for lubrication flow. The plug itself is segmented with distinct inlet and outlet recesses positioned at opposite ends to direct lubrication flow through the pin.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A simple cylindrical plug with inlet and outlet recesses serves as an intermediary component inserted into the blind bore of the pin. This plug mediates the lubrication flow path, directing lube from the inlet bore through the pin to the outlet bore, replacing complex pressed-ball or drawn-steel-plug designs.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If pressed ball or drawn steel plug methods are used, then lubrication delivery is improved, but risk of pin deformation and plug failure increases

Engineering Contradiction:
Improvelubrication deliveryVSAvoidpin integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The plug is designed as a simple, replaceable component made from polymer material that can be easily inserted and removed. Rather than permanently deforming the pin with pressed balls or drawn plugs, this disposable-style plug can be installed without compromising pin structural integrity and replaced if needed.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The plug is constructed from polymer material that combines lubrication channeling functionality with mechanical compatibility. The polymer material provides sufficient structural integrity to maintain the lubrication passages while being gentle enough on the pin bore to avoid deformation during installation.

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If multiple complex machining operations are used, then precise lubrication flow paths are achieved, but manufacturing cost and debris generation increase

Engineering Contradiction:
Improvebore alignmentVSAvoidmachining complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The inlet recess and outlet recess are pre-formed in the plug at positions that correspond to the inlet and outlet bores of the pin. When the plug is inserted into the blind bore, the recesses automatically align with the bores, eliminating the need for complex post-assembly machining or alignment operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of machining complex flow paths directly into the pin, the invention inverts the approach by creating a simple plug with pre-formed recesses that directs lubrication flow. The complex lubrication channeling function is transferred to the removable plug rather than being permanently machined into the pin structure.

Inventive Principle:
Principle #13The other way round (Inversion)

4Ease of manufacture

If simple pin designs are used, then manufacturing is easier, but sufficient lubrication flow to planetary bearing is not achieved

Engineering Contradiction:
Improvepin fabricationVSAvoidlubrication flow
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The lubrication function is segmented from the pin structure itself and placed in a separate plug component. The pin maintains its simple solid structure with a blind bore, while the plug contains the inlet/outlet recesses that create the lubrication flow path. This segmentation allows each component to be manufactured simply while achieving reliable lubrication delivery when assembled.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2875262B1Plug for a planetary pin assembly
Publication Date: 2019.09.04 JTEKT BEARINGS NORTH AMERICA LLC
  • EP2875262B1 patent drawingFigure 1~2

AI summary

A pin assembly for use in a planetary gear, including a pin defining a blind bore therein, the blind bore extending axially from an opening and terminating with an end face, the pin defining an inlet bore and an outlet bore, and a plug including a substantially cylindrical body including a circular base wall and a sidewall extending from its outer perimeter, the sidewall defining an inlet recess and an outlet recess. The inlet recess and outlet recess of the plug are aligned with the inlet bore and outlet bore, respectively, of the pin when the plug is inserted in the pin.