Wheel Assembly Constant Force Mechanism Wear Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current caster systems for material handling vehicles require frequent periodic adjustments due to drive wheel wear, which is labor-intensive and inefficient, and lack a clear indication for maintenance needs.
Innovation Solution
A wheel assembly with a constant force mechanism that includes a first and second support structure, movable carriages, and resistance devices, providing a substantially constant force in one regime and variable force in another, combined with a position sensor system to monitor wear and alert maintenance when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional casters are used without constant force mechanism, then the structure is simpler and cost is lower, but frequent periodic adjustments are required due to drive wheel wear
Solution Approach 1:
The patent applies the dynamics principle by implementing a constant force mechanism that automatically adjusts caster downward force based on drive wheel wear. As the drive wheel wears and the vehicle tilts, the constant force mechanism dynamically adjusts the caster force to maintain optimal contact, eliminating the need for manual periodic adjustments while adapting to changing operational conditions.
2Ease of operation
If periodic caster adjustments are performed manually with shims, then the caster can be adjusted, but the process is labor intensive and requires vehicle elevation
Solution Approach 1:
The constant force mechanism embodies the self-service principle by automatically compensating for drive wheel wear without requiring manual intervention. The mechanism self-adjusts the caster downward force based on the vehicle's tilt angle caused by wheel wear, eliminating the need for labor-intensive manual adjustment processes and reducing maintenance time.
3Ease of operation
If adjustment screws are used to raise or lower caster, then adjustment is easier without removing caster, but the adjustment point is under the vehicle requiring floor hole
Solution Approach 1:
The patent applies the extraction principle by removing the need for floor modifications entirely. Instead of requiring adjustment points under the vehicle through floor holes, the constant force mechanism is integrated into the wheel assembly structure itself, providing adjustment functionality without any vehicle floor modifications.
4Reliability
If position sensor system is added to monitor wheel wear, then maintenance can be alerted timely, but the device complexity increases
Solution Approach 1:
The position sensor system implements the feedback principle by continuously monitoring the downward force applied to the caster wheel and transmitting this information to a receiver. When the sensor detects that the downward force exceeds a predetermined threshold indicating drive wheel wear, it triggers a maintenance alert, providing timely feedback for scheduled maintenance without requiring complex manual inspection procedures.
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
Reduces the frequency of caster wheel maintenance, maintains optimal vehicle performance by providing a constant downward force and alerting technicians when drive wheel replacement is needed, thus improving operational efficiency.
Implementation Method 1
a first resistance device opposes movement of the first carriage along the length of the first support structure, a second resistance device opposes movement of the second carriage along the length of the second support structure
Implementation Method 2
Document JP 2000-142012 A discloses a wheel assembly comprising a suspension system with a coil spring that acts as a constant force mechanism
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A wheel assembly (10, 110), comprising: a wheel (16 , 80, 116) having an axle (86); and a constant force mechanism (48, 50) coupled to the wheel (16, 80, 116), the constant force mechanism (48, 50) comprising: a horizontal support (52); a horizontal carriage (56) associated with the horizontal support (52); a vertical support (54) oriented perpendicular with respect to the horizontal support (52); a vertical carriage (58) associated with the vertical support (54); and a rigid arm (70) that is pivotally coupled with the horizontal carriage (56), the vertical carriage (58), and the axle (86), wherein the rigid arm (70) is coupled with the vertical carriage (58) at a point (62) intermediate where the rigid arm (70) is coupled with the horizontal carriage (56) and the axle (86), wherein the horizontal carriage (56) is capable of being urged along the horizontal support (52), and wherein the vertical carriage (58) is capable of being urged along the vertical support (54).