PTO Coupling Assembly Segmentation for Rapid Implement Connection

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Solution Overview

Problem

Existing coupling assemblies for connecting implement propeller shafts to tractor PTO drives are cumbersome and time-consuming to connect and disconnect, particularly due to the size and location of the PTO coupling member.

Innovation Solution

A coupling assembly comprising a PTO adapter shaft with internal splines and a PTO stub shaft with external splines, featuring a smaller diameter shaft portion with journals and a chamfer, allowing easy alignment and secure engagement through tapered bore portions and an annular resilient member for quick and easy connection and disconnection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional PTO coupling member is used to connect the implement propeller shaft to the tractor PTO drive, then the connection is secure and reliable, but the hook-up process is time-consuming and difficult due to the size and location of the coupling member

Engineering Contradiction:
Improveease of connectionVSAvoidtime for hook-up
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The coupling assembly is divided into separate components: a PTO adapter shaft that remains on the implement and a PTO stub shaft that connects to the tractor. This segmentation allows the implement to stay prepared while only the smaller stub shaft needs to be connected during hookup, significantly reducing connection time and effort.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The PTO adapter shaft acts as an intermediary component that stays permanently mounted on the implement propeller shaft. It provides a ready-made connection interface that simply needs to receive the PTO stub shaft, eliminating the need to manually assemble the entire coupling mechanism during hookup.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the PTO adapter shaft is designed with a single large bore for spline engagement, then the spline connection is robust, but the alignment and insertion of the PTO stub shaft becomes difficult

Engineering Contradiction:
Improvespline engagement reliabilityVSAvoidease of alignment
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The single large bore is segmented into two concentric bores: an outer bore that receives the external splines of the PTO stub shaft, and an inner bore that forms internal splines. This segmentation allows the PTO stub shaft to be guided into proper alignment through the outer bore while the internal splines engage with the external splines, making alignment straightforward.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inner bore with internal splines is nested within the outer bore. The PTO stub shaft passes through the outer bore while its external splines engage with the internal splines of the inner bore, creating a nested engagement that ensures proper alignment and robust connection simultaneously.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If the PTO adapter shaft uses a standard PTO drive shaft design, then the design is simple and well-established, but it cannot be left connected to the implement propeller shaft while allowing quick replacement

Engineering Contradiction:
Improvereusability of adapter shaftVSAvoidcoupling assembly structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The PTO adapter shaft is designed with universal functionality to remain permanently mounted on the implement propeller shaft while accommodating different PTO stub shaft connections. It serves both as a permanent mounting component and as a connection interface, eliminating the need to remove or replace the entire coupling mechanism when changing implements.

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

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

Enables rapid and secure connection of the implement propeller shaft to the PTO drive, reducing the time required for hook-up and ensuring proper alignment and indexing of splines to prevent damage, while allowing for easy removal and reinstallation.

Implementation Method 1

The tapered bore portions and annular resilient member provide a friction fit that secures the PTO adapter shaft to the PTO stub shaft

Methodology Applied
Scientific EffectFriction fit: Friction

Implementation Method 2

external splines for meshing engagement with the internal splines of the PTO adapter shaft

Methodology Applied
Scientific EffectSpline meshing engagement: Gear

Data Source

PatentEP3011816B1Coupling assembly for connecting an implement propeller shaft to a PTO drive of a tractor
Publication Date: 2020.04.22 DEERE & CO
  • EP3011816B1 patent drawingFigure 1
  • EP3011816B1 patent drawingFigure 2
  • EP3011816B1 patent drawingFigure 3~4

AI summary

A coupling assembly (10) for connecting an implement propeller shaft of a PTO drive of a tractor, the coupling assembly (10) comprises a PTO adapter shaft (20) and a PTO stub shaft (14). The PTO adapter shaft (20) has a first bore (25) which forms internal splines (34) and has a second blind bore (26) which extends from the first bore (25) to an end wall (28) which faces towards the first bore (25). The first bore (25) has a larger diameter and the second blind bore (26) has a smaller diameter. The PTO stub shaft (14) has a larger diameter shaft portion (60) with external splines (61) for meshing engagement with the internal splines (34) of the PTO adapter shaft (20) and has a smaller diameter shaft portion (58) which extends away from the larger diameter shaft portion (60). The smaller diameter shaft portion (58) has an outer end with a chamfer (64) and first and second journals (66, 68) formed thereon. The first journal (66) is spaced axially apart from the second journal (68). The first and second journals (66, 68) are slidably received by the second blind bore (26).