Cutting Blade Assembly with Radial Deflection for Jam Reduction
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Solution Overview
Problem
Cutting blade assemblies in grinder pumps and similar applications face challenges in efficiently processing diverse debris types, including jams and increased load, due to issues like stringy debris wrapping, resilient debris wedging, and hard debris damage, particularly when handling wastewater with fibrous materials.
Innovation Solution
A cutting blade assembly with a cutting plate and hub featuring deflection features and multiple cutting edges, configured for relative rotation to deflect debris radially outward and perform scissor-type and chipping-type cutting actions, minimizing jamming and torque requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the drive motor torque is increased to handle various debris types, then the cutting blade assembly can process more difficult materials, but the motor load and energy consumption increase
Solution Approach 1:
The cutting blade assembly is segmented into multiple cutting blades arranged radially around the hub, allowing debris to be processed in sequential stages rather than requiring a single high-torque blade. This segmentation distributes the cutting load across multiple blades, reducing peak motor torque requirements while maintaining versatility in handling different debris types
Solution Approach 2:
The cutting blade assembly utilizes dynamic elements including the radially outwardly extending deflection features that flexibly interact with debris, and the multi-blade configuration that creates varying cutting zones as debris passes through. This dynamic arrangement allows the system to adapt to different debris types without requiring maximum torque for all conditions, optimizing energy consumption
2Reliability
If the cutting blade assembly is strengthened to handle hard debris, then durability improves, but device complexity and manufacturing cost increase
Solution Approach 1:
The cutting blade assembly applies local quality by providing enhanced cutting edges and deflection features only at specific locations where debris interaction occurs, rather than uniformly strengthening the entire assembly. The deflection features are strategically positioned to handle specific debris types, maintaining overall structural simplicity while improving localized durability
Solution Approach 2:
The patent utilizes parameter changes by varying the material properties and geometric parameters of different components within the assembly. The cutting blades have optimized thickness and edge geometry for durability, while the deflection features have different dimensional parameters to handle various debris types. This selective parameter optimization maintains reliability without requiring uniform strengthening of the entire assembly
3Productivity
If the allowable particle size is increased to process larger debris, then processing capability improves, but jamming and blockages increase
Solution Approach 1:
The cutting blade assembly segments the debris processing function across multiple radially arranged blades, creating multiple cutting zones and flow paths. This segmentation allows larger debris particles to be processed in stages by different blades, reducing the likelihood of jamming while maintaining the ability to handle larger particle sizes
Solution Approach 2:
The patent introduces radial deflection features that extend outward from the hub, adding a radial dimension to debris management. These deflection features guide debris radially outward through the cutting zone, creating additional flow paths and reducing the probability of axial blockages, thereby enabling processing of larger particles without increasing jamming
4Productivity
If stringy debris is processed, then cutting effectiveness is maintained, but wrapping around the cutting blade assembly increases
Solution Approach 1:
The cutting blade assembly employs dynamic deflection features that radially outwardly extend and interact with stringy debris during rotation. These deflection features create dynamic forces that prevent stringy materials from wrapping around the hub by continuously directing them through the cutting zone, maintaining cutting effectiveness while eliminating the wrapping problem
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
The assembly effectively processes various debris types by reducing jamming and torque spikes, ensuring efficient operation and uniform torque on the motor, while maintaining consistent fluid flow and reducing particle size.
Implementation Method 1
Each of the deflection features is configured to deflect debris radially outward away from the opening when the cutting hub is rotated relative to the cutting plate
Implementation Method 2
the leading edge of the cutting arm passes adjacent to the plurality of cutting holes so that the relative rotation of the cutting plate and the cutting hub defines a cutting action between the leading edge and the at least one cutting edge
Implementation Method 3
When the cutting plate and the cutting hub are rotated relative to each other, the leading edge of the cutting arm passes adjacent to the plurality of cutting holes so that the relative rotation of the cutting plate and the cutting hub defines a cutting action
Implementation Method 4
the fin is configured to urge debris away from the opening of the cutting plate
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Embodiments of the invention provide a cutting blade assembly (10) operably coupleable to a fluid pump. The cutting blade assembly comprises a cutting plate (14) and a cutting hub (16). The cutting plate may have a front axial surface (20), an opening (24), and a plurality of cutting features (32). Each of the plurality of cutting features may define a pair of cutting edges (56). The cutting hub may be disposed at least partially within the opening of the cutting plate and may have a cutting arm (58) and fin (82) adjacent to the front axial surface. The cutting arm may define an arcuate front surface (70) having a leading edge (62). When the cutting plate and the cutting hub are rotated relative to each other, the leading edge of the cutting arm may pass adjacent to the plurality of cutting features so that the relative rotation of the cutting plate and the cutting hub defines a cutting action between the cutting arm and each cutting feature.