Chainsaw Chain Tension Estimation Using Motor Shaft Load
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Solution Overview
Problem
The existing methods for determining the tension of a chainsaw chain are cumbersome and prone to incorrect adjustments, leading to safety issues and increased wear on components, as they require manual procedures that are often misinterpreted.
Innovation Solution
A chainsaw with a tension estimation arrangement that senses the load on the motor shaft to estimate the chain tension, allowing for quick, convenient, and accurate tension checks without the need for manual procedures, using existing components and modes such as speed sensing and electric current/voltage monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual tension checking procedures are used, then the user can determine chain tension, but the procedure is cumbersome and prone to incorrect adjustments
Solution Approach 1:
The patent replaces the manual mechanical tension checking procedure with an automated electronic sensing system. The tension estimation arrangement uses sensors to detect chain tension and processes the signals electronically to determine whether adjustment is needed, eliminating the need for manual pulling and visual assessment by the user.
Solution Approach 2:
The chainsaw performs self-diagnosis of chain tension automatically. The tension estimation arrangement continuously monitors chain tension and provides feedback to the user without requiring manual intervention, enabling the system to assess its own state and guide the user on whether adjustment is needed.
2Reliability
If manual tension checking is performed frequently, then chain tension can be maintained, but it requires user time and manual intervention
Solution Approach 1:
The tension estimation arrangement enables continuous monitoring of chain tension during operation. Rather than requiring periodic manual checks that interrupt work, the system continuously assesses tension and provides real-time feedback, maintaining reliable tension monitoring without time loss.
Solution Approach 2:
The system automatically and continuously monitors chain tension without requiring user intervention. The tension estimation arrangement performs repeated assessments during operation, eliminating the need for the user to allocate time for manual checking while maintaining reliable tension control.
3Stability of the object's composition
If the chain is tensioned too tightly, then the chain stays on the guide bar, but it risks breaking during operation
Solution Approach 1:
The tension estimation arrangement provides continuous feedback on chain tension levels. By monitoring tension and communicating the status to the user, the system enables informed adjustment decisions that maintain optimal tension - tight enough for stability but not excessive to cause breaking.
Solution Approach 2:
Instead of requiring the user to make precise manual adjustments, the system provides clear guidance on whether tension is adequate, too loose, or too tight. This allows for conservative, incremental adjustments that achieve sufficient tension stability without risking over-tightening and chain failure.
4Ease of operation
If the chain is tensioned too loosely, then the chain is easier to adjust, but it can come off the guide bar creating unsafe situations
Solution Approach 1:
The tension estimation arrangement continuously monitors chain tension and provides feedback to the user. This real-time information allows the user to maintain tension within the safe optimal range, preventing the chain from becoming too loose and coming off the guide bar while avoiding excessive tightening.
Solution Approach 2:
The system provides clear guidance that encourages maintaining slightly higher tension than the minimum required. By guiding users to keep tension in the optimal range rather than allowing it to become loose, the system prevents safety hazards while maintaining ease of operation through simple binary feedback.
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 provides a safer and more efficient method for maintaining optimal chain tension, reducing the risk of accidents and component wear, while enabling more frequent tension checks without manual intervention, and is cost-efficient in manufacturing.
Implementation Method 1
a tension estimation arrangement configured to sense a load on the motor shaft, and configured to estimate the tension of the chain around the guide bar on the basis of the sensed load on the motor shaft
Implementation Method 2
A motor, such as a combustion engine or an electric motor, is arranged to rotate the chain around the guide bar, usually via a motor shaft, a transmission and a drive sprocket
Data Source
Figure 1~2
Figure 3~4
AI summary
Herein a chainsaw (1) is disclosed comprising a guide bar (3) and a chain (5) moveably arranged around the guide bar (3). The chainsaw (1) comprises an motor (9) comprising a motor shaft (11), wherein the motor (9) is configured to drive the chain (5) via the motor shaft (11). The chainsaw (1) further comprises a tension estimation arrangement (13) configured to sense a load on the motor shaft (11), and configured to estimate the tension of the chain (5) around the guide bar (3) on the basis of the sensed load on the motor shaft (11). The present disclosure further relates to a method of estimating tension of a chain (5) of a chainsaw (1).