Self-aligning tensioner spring pretension eliminates bearing clearance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Self-aligning tensioners in internal combustion engine belt drives often experience radial and axial clearance due to tolerances in the sliding bearing, leading to resonance and increased wear, particularly during high-frequency oscillations, resulting in rattling noises.
Innovation Solution
Incorporating at least one spring element between the sliding bearing area and the tensioning arm to pretension the base unit and tensioning arm, eliminating radial and axial clearance, and adjusting the resonance frequency to reduce rattling noises by changing the bearing's resonance behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a sliding bearing is used to support the tensioning arm for rotational movement, then the tensioning arm can move relative to the base unit, but radial and axial clearance occurs due to tolerances leading to resonance and increased wear
Solution Approach 1:
A spring element is introduced to apply preliminary tensioning force to the sliding bearing, pre-compressing the bearing surfaces to eliminate clearance before operation begins. This preliminary action ensures the bearing remains in constant contact during high-frequency oscillations, preventing resonance and reducing wear while maintaining the rotational movement capability of the tensioning arm
2Device complexity
If the sliding bearing operates without pretensioning, then the structure remains simple, but bearing gap causes rattling noises and significantly increased wear during high-frequency oscillations
Solution Approach 1:
The spring element changes the operational parameters of the sliding bearing by applying continuous pretensioning force, transforming the bearing from a loose-fitting configuration to a pre-compressed state. This parameter change eliminates the bearing gap that causes rattling noises and excessive wear during high-frequency oscillations, while the spring element itself is designed to be compact to minimize the increase in device complexity
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 solution effectively reduces bearing clearance, minimizes rattling noises, and extends the service life of the self-aligning tensioner by shifting the natural resonance outside the operating frequencies, ensuring stable operation and reduced wear.
Implementation Method 1
there is at least one spring element tensioning the base unit and the tensioning arm against each other. This means that the sliding bearing between the tensioning arm and the base unit is pretensioned in a spring elastic way
Implementation Method 2
the at least one spring element has a surface designed as an anti-friction surface. Therefore, the spring element can be integrated in an especially narrow installation space. If the anti-friction surface is here supported/contacted preferably in the radial direction and/or in the axial direction on the sliding bearing area or the tensioning arm
Data Source
AI summary
A self-aligning tensioner (1) for an endless traction mechanism drive in an internal combustion engine is provided, including a base unit (2) and a separate annular tensioning arm (3), the tensioning arm (3) being slidably mounted in a sliding bearing area (4) of the base unit (2) in order to allow a rotational movement relative to the base unit (2); at least one spring element (5, 6) that tensions the base unit (2) and the tensioning arm (3) against each other is inserted between the sliding bearing area (4) of the base unit (2) and the tensioning arm (3).