Forestry Harvester Tree Feeder With Slip Mid-Roller Coupling

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Solution Overview

Problem

Existing forestry harvesters face issues with smooth and reliable tree feeding due to idle rotation of feed rollers caused by hydraulic motor leakage, leading to reduced feed speed and potential surface scratching of trees.

Innovation Solution

A tree feeder system with a hydraulic circuit connecting right and left hydraulic motors of feed rollers in series with mid-roller motors, featuring an inner and outer wheel with a ring-shaped rotation transmission member to allow slipping and maintain consistent tree feeding without idle rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hydraulic motors are connected in series to enable smooth tree feeding, then feed reliability is improved, but idle rotation occurs when leakage happens

Engineering Contradiction:
Improvefeed reliabilityVSAvoididle rotation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A differential mechanism is introduced as an intermediary between the hydraulic motors and feed rollers. This mechanism allows the system to accommodate speed differences caused by hydraulic leakage while preventing idle rotation of the feed rollers, thus resolving the contradiction between feed reliability and idle rotation prevention

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system transitions from a rigid speed-synchronized connection to a dynamic differential connection. The differential mechanism enables the feed rollers and mid-roller to rotate at different speeds temporarily, absorbing the speed difference caused by leakage without causing idle rotation, while still achieving reliable tree feeding

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If feed rollers rotate at same peripheral speed as mid-roller, then smooth feeding is achieved, but speed differences cause idle rotation

Engineering Contradiction:
Improvesmooth feedingVSAvoidfeed speed consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The differential mechanism serves as a mediator that decouples the strict speed synchronization requirement. It allows the feed rollers and mid-roller to operate with speed differences without causing idle rotation, maintaining smooth feeding while improving feed speed consistency through the speed-difference-absorbing function

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Ensures reliable and efficient tree feeding by allowing the outer wheel to roll on the inner wheel when motor speed differences occur, preventing idle rotation and maintaining desired feed speed while preventing surface damage.

Implementation Method 1

the ring-shaped rotation transmission member is fixedly attached to an inner surface of the outer wheel or an outer surface of the inner wheel, and configured to transmit a rotation of the inner wheel to the outer wheel, and, when a difference in rotational speed arises between the mid-roller and each of the left and right feed rollers, allow the outer wheel to roll on the inner wheel in a slipping manner

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3711476B1Wood feeder for forestry harvester
Publication Date: 2024.01.31 MATSUMOTO RYOZO
  • EP3711476B1 patent drawingFigure 1
  • EP3711476B1 patent drawingFigure 2
  • EP3711476B1 patent drawingFigure 3

AI summary

Provided is a tree feeder of a forestry harvester capable of smoothly and reliably feeding a felled tree under cooperation between a mid-roller and a pair of right and left feed rollers while avoiding idle rotation of the feed rollers, even when a difference in rotational speed arises between the mid-roller and each of the feed rollers. The tree feeder of the forestry harvester comprises a hydraulic circuit in which each of a pair of right and left hydraulic motors of a pair of right and left feed rollers is hydraulically connected in series with a corresponding one of a pair of left and right hydraulic motors of a mid-roller, wherein the tree feeder is configured to rotate the mid-roller and the right and left feed rollers by the hydraulic motors thereof so as to feed a felled tree in a manner enabling delimbing, and wherein the mid-roller comprises: an inner wheel fixedly connected to respective rotary shafts of the pair of left and right hydraulic motors thereof; an outer wheel; and a ring-shaped rotation transmission member disposed between the inner wheel and the outer wheel, wherein the ring-shaped rotation transmission member is fixedly attached to an inner surface of the outer wheel or an outer surface of the inner wheel, and configured to transmit the rotation of the inner wheel to the outer wheel, and, when a difference in rotational speed arises between the mid-roller and each of the left and right feed rollers, allow the outer wheel to roll on the inner wheel in a slipping manner.