Wood Chipper Screen Basket Pivot Mechanism

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Solution Overview

Problem

Existing wood chippers have bulky and complex displacement mechanisms for screen baskets, which increase the external dimensions and maintenance effort of the machine.

Innovation Solution

A compact drive device is integrated into the wood chipper's holding element, using a coupling element with pins and a worm wheel to pivot the screen basket without a separate external drive, allowing for easy access during maintenance without enlarging the machine's circumference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a separate external drive device is provided on the outer circumference of the screen basket, then the screen basket can be pivoted for maintenance access, but the external dimensions and device complexity of the machine significantly increase

Engineering Contradiction:
Improveaccess for maintenanceVSAvoiddisplacement mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the drive function for the screen basket into the existing drive shaft structure. The drive device is integrated into the drive shaft itself, combining the functions of power transmission and screen basket actuation into a single component, thereby avoiding the need for separate external drive mechanisms

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The drive shaft is designed to serve multiple functions: it transmits power for wood chipping operations and simultaneously provides the drive mechanism for pivoting the screen basket. This multi-functionality eliminates the need for dedicated separate drive devices, reducing overall device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If a separate external drive device is provided on the outer circumference of the screen basket, then the screen basket can be pivoted for maintenance access, but the external dimensions of the machine significantly increase

Engineering Contradiction:
Improveaccess for maintenanceVSAvoidmachine external dimensions
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The drive mechanism for the screen basket is nested within the existing drive shaft structure. The drive device is positioned inside or along the drive shaft, utilizing the existing spatial envelope of the machine rather than adding external protrusions, thus maintaining compact external dimensions

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If a separate external drive device is provided on the outer circumference of the screen basket, then the screen basket can be pivoted for maintenance access, but the maintenance effort for individual machine elements significantly increases

Engineering Contradiction:
Improveaccess for maintenanceVSAvoidmaintenance effort
Core Design Contradiction:
Ease of operationVSEase of repair

Solution Approach 1:

By combining the screen basket drive function into the existing drive shaft, the number of separate machine elements is reduced. This integration means fewer components require maintenance, and when maintenance is needed, the drive mechanism is already accessible as part of the drive shaft assembly

Inventive Principle:
Principle #5Merging (Combining)

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

This solution reduces the size and complexity of the displacement device, enabling safe and efficient pivoting of the screen basket by 180° for maintenance without increasing the machine's dimensions, thus simplifying maintenance and reducing maintenance effort.

Implementation Method 1

at least one coupling element which is formed both in the holding element and in at least one end face of the drive shaft that faces the holding element recess can be coupled

Methodology Applied
Scientific EffectMechanical coupling: Mechanical Fastener

Implementation Method 2

The drive device (7) for the screen basket (2), which is different from the drive for the wood chipper (1), is formed in the holding element (4) and has essentially a worm wheel (8) and a worm (9), which can be set in rotation, for example, with a percussion drill

Methodology Applied
Scientific EffectWorm drive: Worm Drive

Data Source

PatentEP3789169B1Wood chipping machine
Publication Date: 2022.04.27 ESCHLBOCK MASCHBAUU
  • EP3789169B1 patent drawingFigure 1
  • EP3789169B1 patent drawingFigure 2
  • EP3789169B1 patent drawingFigure 3

AI summary

In a wood chipper (1) with a chipping drum and at least one screen basket (2) movable along an outer circumference of the chipping drum, the wood chipper (1) has at least one drive with a drive shaft (3) and at least one drive device (7) for pivoting the screen basket (2) from or into its working position, such that a fastening element (11) of the screen basket (2) is fixed to a retaining element (4) which encompasses one end of the drive shaft (3) of the wood chipper (1) and is rotatably mounted relative to the drive shaft (3), that at least one coupling element (12) which can be engaged both in the retaining element (4) and in at least one recess formed in an end face (18) of the drive shaft (3) facing the retaining element (4) is provided, and that a drive device (7) for the screen basket (2) which is different from the drive of the wood chipper (1) is formed in the retaining element (4), as well as methods for this.