Chainsaw Chain Lifting Mechanism for Noise and Sag Control
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Solution Overview
Problem
Motor chainsaws experience increased noise levels and saw chain misalignment, leading to operational disruptions and potential damage due to reduced saw chain tension and sagging strands, which affects the contact angle and contact forces between the saw chain and guide rail.
Innovation Solution
A motor chainsaw equipped with a chain lifting device that deflects the saw chain away from the guide rail's longitudinal axis, reducing slack and maintaining a constant contact angle, thereby reducing noise and preventing material fatigue, along with a protective contact system to alert the operator of tension needs and prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the saw chain operates for an extended period, then the chain stretches and tension is lost, but this causes increased noise levels and chain sagging
Solution Approach 1:
The chain lifting device automatically compensates for chain stretch by continuously lifting the slack side of the chain, maintaining proper tension without requiring manual intervention or chain replacement during operation
Solution Approach 2:
The system changes the vertical position parameter of the chain by lifting the slack side, thereby maintaining optimal chain tension and contact angle with the guide bar throughout extended operation periods
2Object-affected harmful factors
If the chain tension is maintained high, then noise is reduced, but this increases contact forces and material fatigue
Solution Approach 1:
The chain lifting device applies localized support only to the slack side of the chain, maintaining proper tension and contact angle without uniformly increasing tension throughout the entire chain, thus reducing noise while minimizing additional contact forces on the guide bar
Solution Approach 2:
The system dynamically adjusts the chain position by continuously lifting the slack side to maintain optimal contact angle with the guide bar, ensuring quiet operation while preventing excessive contact forces through adaptive positioning rather than static tension increase
3Stability of the object's composition
If the chain sags on the slack side, then contact angle increases, but this increases noise levels
Solution Approach 1:
The chain lifting device continuously monitors and corrects chain sag by automatically lifting the slack side, maintaining proper contact angle and preventing noise generation throughout operation without manual intervention
Solution Approach 2:
The chain lifting device proactively prevents chain sag and contact angle increase by continuously lifting the slack side before excessive sag can occur, thereby preventing noise generation rather than correcting it after the fact
Data Source
Figure 1~2
Figure 3~6
Figure 7~10
AI summary
The invention relates to a motorized chainsaw with a housing (2) and a drive motor (3). The drive motor (3) drives a saw chain (7) guided on a guide rail (5) via a drive sprocket (4). The guide rail (5) is held on the housing (2) by a releasable fastening device (8) and, when the fastening device (8) is released, is displaceable relative to the housing (2) in the direction of its longitudinal axis (6) by means of a tensioning device (10). The saw chain (7) has a slack run (9) between the drive sprocket (4) and the guide rail (5). The motorized chainsaw (1) includes a chain lifting device (11) designed separately from the tensioning device (10). The chain lifting device (11) is designed to deflect the saw chain (7) away from the longitudinal axis (6) of the guide rail (5).