PTO Gearbox Adaptive Transmission Control

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Solution Overview

Problem

Agricultural working machines, such as tractors, face challenges in efficiently using power take-off (PTO) shafts due to fixed gear ratios, which limit adaptability to varying power requirements and lead to heavy loads during start-up of high-inertia attachments, making it difficult for operators to achieve desired PTO shaft speeds and efficient operation.

Innovation Solution

A control unit is implemented to automatically adjust the PTO shaft transmission ratio based on operating parameters, allowing for adaptive speed control of the PTO shaft by regulating the drive motor speed, enabling stepless changes and gentle acceleration/deceleration of attached implements, thus optimizing power usage and reducing operator complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fixed gear ratios are used in the PTO transmission, then the structure is simple and reliable, but the adaptability to varying power requirements is poor

Engineering Contradiction:
Improveadaptability to varying power requirementsVSAvoidtransmission system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a variable transmission ratio system for the PTO shaft that allows dynamic adjustment during operation. The transmission ratio can be changed while the tractor is moving and the PTO is operating, enabling adaptation to different power requirements without stopping work. This resolves the contradiction by making the transmission system dynamic rather than fixed, allowing high adaptability while maintaining reasonable structural complexity through automated control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the transmission ratio parameter of the PTO shaft based on operating conditions. By automatically adjusting the transmission ratio according to the tractor's operating state and power availability, the system achieves versatile adaptation to different power requirements. This parameter change approach maintains structural simplicity while improving adaptability through intelligent control rather than mechanical complexity.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If economy PTO gears are used to reduce engine speed, then fuel consumption decreases, but the ability to handle high power requirements is lost

Engineering Contradiction:
Improvefuel consumptionVSAvoidpower handling capability
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The patent implements dynamic switching between different transmission ratios based on real-time power requirements. When high power is needed (e.g., during harvesting), the system automatically selects appropriate gears to deliver sufficient power. When power requirements are low, it switches to economy gears to reduce fuel consumption. This dynamic adaptation resolves the contradiction by making power handling capability available on-demand without permanently sacrificing fuel efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the transmission ratio parameter dynamically based on operating conditions and power demands. The system monitors power requirements and automatically adjusts the transmission ratio to optimize both fuel consumption and power delivery. This allows the system to achieve low fuel consumption during normal operation while maintaining the ability to handle high power requirements when needed.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If manual adjustment of PTO shaft speed is required, then the control is simple, but the operator burden increases and specialist knowledge is needed

Engineering Contradiction:
Improveease of PTO shaft speed controlVSAvoidcontrol system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent implements an automated control system that monitors operating parameters and automatically adjusts the PTO shaft speed without operator intervention. The system self-regulates the transmission ratio based on detected operating conditions, eliminating the need for the operator to manually adjust settings or possess specialized knowledge. This self-service approach resolves the contradiction by making the system easy to operate while managing the necessary complexity through automated intelligence.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent incorporates feedback mechanisms that continuously monitor operating parameters such as engine speed, load conditions, and power availability. Based on this feedback, the control system automatically adjusts the PTO transmission ratio to maintain optimal performance. This feedback loop eliminates the need for manual adjustment while keeping the control system manageable through intelligent algorithms rather than complex mechanical controls.

Inventive Principle:
Principle #23Feedback

4Productivity

If PTO gears are shifted under load, then continuous work is possible, but the transmission system becomes more complex

Engineering Contradiction:
Improvecontinuous work capabilityVSAvoidtransmission shifting mechanism complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic transmission system capable of shifting gears under load conditions. The system can change transmission ratios while the tractor is moving and the PTO is operating, enabling continuous work without stopping. This dynamic shifting capability resolves the contradiction by allowing productivity maintenance during gear changes while managing transmission complexity through automated control mechanisms that simplify the shifting process.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2857246B1Agricultural work machine
Publication Date: 2018.01.31 CLAAS TRACTOR
  • EP2857246B1 patent drawingFigure 1

AI summary

An agricultural machine, in particular a tractor (1), with a drive motor (3) and a power take-off (PTO) gearbox (5) driven thereby with an output PTO shaft (6) for driving an implement (2) attachable to the machine (1), wherein the PTO gearbox (5) has a variable transmission (i5), is characterized in that the transmission (i5) of the PTO gearbox (5) is adjustable depending on at least one operating parameter of the machine (1) and/or the implement (2).