Eccentric Cam Scraper Assembly for Baler Plunger
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Solution Overview
Problem
Existing scraper assemblies for balers fail to effectively prevent crop material from extruding past the reciprocating plunger and becoming lodged between the plunger and the compression chamber walls, leading to inefficiencies in the baling process.
Innovation Solution
A scraper assembly with a cam insert and follower plate system that includes eccentrically located annular projections and a through bore, allowing for adjustable positioning of the scraper plate relative to the compression chamber walls, and utilizing fasteners with internal and external threads to secure the components and distribute clamping forces, thereby preventing shear forces on the fasteners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a scraper assembly is attached to the reciprocating plunger to prevent crop material from extruding, then the effectiveness of preventing material extrusion is improved, but the complexity of the device increases
Solution Approach 1:
The scraper assembly is divided into separate functional components: a scraper plate for contacting the compression chamber wall, a follower plate for receiving cam insert, and a mounting plate for attachment to the plunger. This segmentation allows each component to be optimized independently and simplifies assembly/maintenance while maintaining effective material prevention.
Solution Approach 2:
The scraper assembly incorporates a cam insert with eccentric annular projections that enable dynamic adjustment of the scraper plate's position and angle relative to the compression chamber wall. This dynamic capability allows the scraper to adapt to varying operational conditions, maintaining effectiveness without requiring a complex fixed multi-component system.
2Adaptability or versatility
If the scraper assembly is made adjustable to position against compression chamber walls, then the adaptability to different wall positions is improved, but the device complexity increases
Solution Approach 1:
The cam insert employs eccentric annular projections where the second projection is offset from the first projection's center. This asymmetric geometry creates a mechanical advantage that enables simple lateral and angular adjustment of the scraper plate through cam rotation, achieving adaptability without complex actuation mechanisms.
Solution Approach 2:
The follower plate serves as an intermediary component between the cam insert and the scraper plate, transmitting the adjustment motion from the cam's rotational movement to the scraper plate's positional change. This intermediary mechanism simplifies the overall adjustment system by converting rotational cam motion into the desired lateral and angular scraper positioning through straightforward mechanical linkage.
3Strength
If fasteners are used to secure the follower plate to the mounting plate, then the strength of the connection is improved, but the shear forces on the fasteners increase
Solution Approach 1:
The mounting plate includes a countersunk region that receives the cam insert's second projection before final assembly. This preliminary positioning feature ensures that the fastener is pre-aligned to engage the cam insert's through-bore at an optimal angle, distributing clamping forces away from shear planes and reducing lateral loads on the fastener while maintaining strong connection.
Data Source
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AI summary
A scraper assembly (44) for a baler (20) includes a mounting plate (50) attached to a face of a plunger (42). The mounting plate (50) includes an annular countersunk region (56) and a concentric mounting bore (58). A follower plate (60) includes an annular aperture (66). A scraper plate (70) is attached to the follower plate (60) for scraping a wall of a compression chamber (34). A cam insert (72) includes a first annular projection (86) seated within the annular aperture (66) of the follower plate (60), and a second annular projection (88) seated within the annular countersunk region (56) of the mounting plate (50). The cam insert (72) further includes a through bore (94) extending through the second annular projection (88). The second annular projection (88) and the through bore (94) are eccentric from a center of the annular aperture (66) and the first annular projection (86). A threaded fastener (102) extends through the through bore (94) of the cam insert (72) and into threaded engagement with the mounting bore (58) in the mounting plate (50).