Lawn Mower Height Adjustment Link Arm Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional height adjustment systems for lawn mowers are complex, time-consuming, and costly due to the need for thick steel link arms and multiple welding operations, which complicate the assembly process.
Innovation Solution
A height adjustment arrangement featuring link arms pivotally attached to the chassis with a transversal rod that absorbs torsional forces, allowing the link arms to be made thinner and eliminating the need for separate wheel axles, using interconnection means like fork portions and snap-locking plastic bushings to simplify assembly and reduce welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional welding-based link arms are used, then structural strength is sufficient, but manufacturing complexity and production cost increase
Solution Approach 1:
The link arm is divided into a plate portion and a tube portion that are detachably connected. The plate portion connects to the chassis while the tube portion connects to the wheel axle, allowing separate manufacturing and assembly without welding. This segmentation maintains structural strength while simplifying manufacturing processes.
Solution Approach 2:
A connection piece serves as an intermediary component between the link arm plate portion and the tube portion. This intermediary element enables detachable connection without welding, facilitating easier assembly and disassembly while maintaining the required mechanical strength for load-bearing operations.
2Strength
If thick steel plate link arms are used, then load-bearing capacity is sufficient, but material cost and weight increase
Solution Approach 1:
The link arm is segmented into a thinner plate portion and a tube portion with different functional optimizations. The plate portion can be thinner since it doesn't need to bear the full load alone, while the tube portion provides additional structural support. This segmentation allows weight reduction while maintaining overall load-bearing capacity.
Solution Approach 2:
The link arm combines different structural forms (plate and tube) to create a composite structure that optimizes both weight and strength. The plate portion provides a broad mounting surface while the tube portion provides structural rigidity, together achieving load-bearing capacity with reduced material usage compared to a solid thick plate design.
3Adaptability or versatility
If multiple separate components are used, then functional requirements are met, but assembly time and production cost increase
Solution Approach 1:
The wheel axle and transversal rod are merged into a single integrated component. This combining eliminates the need for separate assembly of these parts and reduces the number of connection points required, thereby speeding up assembly operations while maintaining the height adjustment functionality through the link arm mechanism.
Solution Approach 2:
The link arm structure serves multiple functions: it provides the height adjustment mechanism through pivotal connection, supports the wheel axle, and maintains structural integrity during operation. By designing the link arm to fulfill multiple roles, the number of separate components is reduced without compromising functional requirements.
Data Source
AI summary
A height adjustment arrangement (1) for a lawn mower (20) for changing a cutting height is provided. The height adjustment arrangement comprises a respective link arm (2a, 2b) pivotally arranged at opposite sides of the chassis (21), and a transversal rod (5) extending between the link arms (2a, 2b) comprising wheel attachment ends (6a, 6b) configured to protrude outwardly from the respective link arm (2a, 2b). The height adjustment arrangement further comprises a locking arrangement (11) for releaseably locking at least one of the link arms (2a, 2b) in a pivot position. The transversal rod comprises connection portions (9a, 9b) which are essentially parallel to the link arms and releasably connected thereto such that pivoting of the link arm (2a, 2b) causes the wheel attachment ends (6a, 6b) to synchronously change the cutting height of the lawn mower chassis (21).