C-Shaped Pulley Assembly for Axial Locking and Belt Wear Control
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Solution Overview
Problem
Existing pulley devices for tensioning idlers or runner rollers suffer from early belt wear and radial deformation under heavy loads, due to inadequate support and rigidity, leading to potential axial movement during service use.
Innovation Solution
A pulley device with a rotatable outer ring and a fixed inner ring, featuring C-shaped pulley parts with protruding portions that fit into recesses on the outer ring, providing enhanced rigidity and preventing axial movement, thus ensuring efficient belt support and reducing wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the pulley is tightened to the outer ring of bearing, then the pulley can be easily installed, but the pulley can slightly axially move during service use
Solution Approach 1:
The patent introduces an intermediary locking mechanism consisting of protrusions on the pulley that engage with recesses on the outer ring of the bearing. This intermediary structure mediates between the simple tightening approach and the need for stable axial positioning, allowing easy installation while preventing axial movement during service.
2Ease of manufacture
If the outer part is made simple in structure, then the manufacturing is easier, but the outer part may be deformed radially inwards by bending under the action of the belt
Solution Approach 1:
The patent applies local quality by providing reinforcement ribs specifically in the radial direction where bending stresses occur during belt operation. The pulley maintains overall structural simplicity for easy manufacturing, but adds localized rigidifying elements exactly where needed to prevent radial inward deformation under belt load.
3Ease of operation
If the pulley part is formed integral with open end, then the installation onto bearing is easier, but the rigidity may be reduced under heavy loads
Solution Approach 1:
The patent uses preliminary action by providing protrusions that are pre-formed on the integral pulley part before installation. These protrusions engage with corresponding recesses on the bearing's outer ring during installation, pre-establishing the axial locking mechanism. This allows the simple integral open-end design for easy installation while ensuring adequate rigidity under heavy loads through the pre-configured locking features.
Data Source
AI summary
A pulley device comprising a pulley and a bearing. The pulley has at least one “C-shaped” pulley part having an inner portion mounted on the bearing, an outer portion having an outer cylindrical surface dedicated to interact with a belt or a chain, and an intermediate portion extending substantially radially between axial ends of inner and outer portions on one axial side of pulley device. The outer cylindrical surface of outer ring is provided with at least one recess having in cross-section, a concave internal profile. The pulley part is provided with at least one protruding portion which inwardly extends beyond the inner cylindrical surface of inner portion. The protruding portion is received in a corresponding recess of outer ring so as to block the pulley part with respect to the outer ring in both axial directions.