Implement Carrier Bypass Valve Actuation for Seal Protection

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Solution Overview

Problem

Prior-art ride-on lawnmowers face issues where the hydraulic pump can damage axle seals and cause oil leakage due to high pressure when the bypass valve is not reset to its normal position after use, making it difficult to move the mower with the engine shut off.

Innovation Solution

An actuating means, such as a foot pedal, is connected to the bypass valve, ensuring it returns to its normal position when the engine is started, preventing oil pressure buildup and potential damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the bypass valve is left in bypass position after use, then the implement carrier can be moved with engine shut off, but the hydraulic pump damages axle seals and causes oil leakage due to high pressure

Engineering Contradiction:
Improvemovement capabilityVSAvoidaxle seal integrity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary action by automatically resetting the bypass valve to the normal position when the engine is started, before the hydraulic pump can generate high pressure. This prevents the harmful condition from occurring in the first place, eliminating the need for manual resetting and preventing seal damage.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the engine start condition to automatically control the bypass valve position. When the engine is started, this signal triggers the bypass valve to return to the normal position, creating a closed-loop control system that prevents high pressure damage while maintaining operational flexibility.

Inventive Principle:
Principle #23Feedback

2Reliability

If the bypass valve is set to normal position, then axle seals are protected from high pressure damage, but the implement carrier cannot be moved with engine shut off

Engineering Contradiction:
Improveaxle seal integrityVSAvoidmovement capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system dynamically adjusts the bypass valve position based on operational requirements. The valve can be manually set to bypass position for movement with engine off, then automatically returns to normal position when engine starts, providing the benefits of both positions at different times without manual intervention.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs self-service by automatically resetting the bypass valve without operator intervention. After manual positioning for movement, the system autonomously returns the valve to the safe normal position upon engine start, eliminating the risk of operator forgetfulness and ensuring seal protection.

Inventive Principle:
Principle #25Self-service

3Device complexity

If manual resetting of bypass valve is required, then system simplicity is maintained, but operator error causes high pressure damage to hydraulic components

Engineering Contradiction:
Improvesystem simplicityVSAvoidhydraulic component safety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system incorporates feedback from the engine start condition to automatically control the bypass valve, creating a simple yet reliable closed-loop control system that eliminates operator error while maintaining overall system simplicity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses an intermediary mechanism (the automatic resetting device) that mediates between the operator's manual valve positioning and the safety requirement. This intermediary automatically performs the resetting function, protecting hydraulic components without significantly complicating the overall system.

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

Prevents damage to axle seals and oil leakage by ensuring the bypass valve is in its normal position when the engine is activated, allowing safe and efficient movement of the lawnmower.

Implementation Method 1

the hydraulic pump forces oil under high pressure into the housing of the hydraulic motor

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

a bypass valve, which is arranged in the closed hydraulic line system and which is settable between a bypass position, in which movement of the implement carrier is possible when the internal combustion engine is shut off, and a normal position, in which such movement is practically impossible

Methodology Applied
Scientific EffectHydraulic valve flow control: Valve

Data Source

PatentEP1901936B1Implement carrier
Publication Date: 2018.03.21 GGP SWEDEN
  • EP1901936B1 patent drawingFigure 1
  • EP1901936B1 patent drawingFigure 2
  • EP1901936B1 patent drawingFigure 3~4

AI summary

An implement carrier has at least one pair of wheels (4a) which is driven by a hydraulic motor (8) included in a closed hydraulic line system (9) , which also comprises a hydraulic pump (10) which is adapted to drive the hydraulic motor and which is driven by an internal combustion engine (6) . The implement carrier has an actuator (5) , which only in an active position allows start of the internal combustion engine (6) . A bypass valve (16) arranged in the hydraulic line system (9) is settable between a bypass position, in which movement of the implement carrier is possible when the internal combustion engine (6) is shut off, and a normal position, in which such movement is impossible. The actuator (5) is connected to the bypass valve (16) in such a manner that the actuator when moving from an inactive position to the active position, if the bypass valve is in its bypass position, moves the bypass valve to its normal position.