Eccentric Vibratory Shaft Design for Utility Compactor Weight Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current eccentric shafts in utility compactors are heavy, leading to high manufacturing and operational costs due to excessive start-up torque requirements, which results in increased wear and tear on motors and hydraulic systems.
Innovation Solution
An eccentric vibratory shaft design featuring a first rotor shaft coaxially spaced from a second rotor shaft, coupled by an offset shaft with angled portions, reducing the ratio of first to second moments of inertia, thereby minimizing weight and start-up torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a traditional eccentric shaft design is used, then the shaft provides sufficient inertia for vibration, but the shaft weight increases and start-up torque requirements increase
Solution Approach 1:
The shaft is divided into multiple segments including a first rotor shaft, a second rotor shaft, and an offset shaft connecting them. This segmentation allows each component to be optimized independently, reducing overall weight while maintaining the necessary moment of inertia for vibration through the distributed mass arrangement of the segmented structure.
Solution Approach 2:
The design transitions from a single-axis rotor to a three-dimensional configuration with offset shafts and angled portions. The offset shaft connects the two rotor shafts at angles, creating a spatial arrangement that distributes mass more efficiently in multiple dimensions, reducing weight while preserving vibratory performance.
2Force
If a heavy eccentric shaft is used, then vibration inertia is sufficient, but motor wear and operational costs increase
Solution Approach 1:
By segmenting the shaft into multiple rotors and offset connections, the moment of inertia is distributed across components rather than concentrated in a single heavy shaft. This reduces the peak start-up torque requirement while maintaining sufficient vibratory force through the coordinated rotation of segmented components.
Solution Approach 2:
The design changes the geometric parameters of the shaft system, specifically the distribution of mass and the arrangement of rotor shafts at angles. This parameter optimization reduces the moment of inertia required for operation, thereby lowering start-up torque and reducing energy loss and motor wear.
3Ease of manufacture
If a straight bar with eccentric weights is used, then the shaft is simple in structure, but manufacturing costs increase
Solution Approach 1:
The shaft is segmented into standardizable components (first rotor shaft, second rotor shaft, offset shaft with angled portions) that can be manufactured independently using conventional processes and assembled. This segmentation enables modular production, reducing overall manufacturing complexity and cost compared to custom-machining a single heavy shaft.
Solution Approach 2:
The offset shaft includes angled portions that can be constructed using composite structures or joined components rather than solid monolithic material. This approach reduces material usage and manufacturing complexity while maintaining structural integrity and functional performance.
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 new design reduces the weight of the compactor and the start-up torque required to rotate the shaft, resulting in cost savings and reduced wear on motor and pump components, while maintaining necessary inertia for vibration.
Implementation Method 1
reducing the ratio of first to second moments of inertia, thereby minimizing weight and start-up torque
Data Source
AI summary
A utility compactor is disclosed that includes a roller disposed on top of and connected to a base plate. The roller has two opposing vertical supports. The compactor also includes an eccentric vibratory shaft extending between and rotatably connected to the two vertical supports of the roller. The eccentric vibratory shaft includes a first rotor shaft coaxially spaced apart from a second rotor shaft. The first and second rotor shafts are coupled together by an offset shaft. The offset shaft has an I-beam cross section and includes a first angled portion, a second angled portion and a center portion disposed between and coupling the first and second angled portions together. The first angled portion is coupled to the first rotor shaft; the second angled portion is coupled to the second rotor shaft. The first and second angled portions are angled with respect to a first axis passing through the first and second rotor shafts such that the center portion has a second axis that is offset from and at least substantially parallel to the first axis.