Torsional Vibration Damper Retainer Hardening for Wear Control
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Solution Overview
Problem
Existing torsional vibration dampers experience reduced vibration damping performance due to increased wear and clearance issues at the radially outer portions of the retainer's inner surface, leading to uneven abrasion and localized wear, which affects the smooth reciprocation of the rolling mass and increases collision impact.
Innovation Solution
The torsional vibration damper incorporates a design where the hardness of the inner surface of the stoppers is increased more significantly in the radially outer portion than the inner portion through high-frequency hardening, shot peening, or coating, ensuring even wear and maintaining clearance homogeneity, thereby preventing localized wear and ensuring smooth reciprocation of the rolling mass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If quenching treatment is applied to the inner surface of the retainer to harden it, then abrasion resistance is improved, but uneven wear occurs at the radially outer portion leading to increased clearance and reduced vibration damping performance
Solution Approach 1:
The patent applies selective hardening treatment to create a hardness gradient across the inner surface of the retainer. The radially outer portion (where wear occurs during high-speed rotation) is hardened to higher hardness (HRC 55-65) than the radially inner portion (HRC 30-45). This local differentiation of material properties ensures that the high-wear area has superior abrasion resistance while maintaining overall component reliability and preventing uneven wear that would lead to clearance increase and performance degradation.
2Reliability
If the rolling mass is allowed to reciprocate within the retainer to damp vibrations, then vibration damping performance is improved, but wear at the contact surface increases leading to clearance and impact issues
Solution Approach 1:
The patent applies hardening treatment to the inner surface of the retainer before the rolling mass begins reciprocating motion. This preliminary surface treatment creates a hardened layer that resists wear from the upcoming reciprocating contact. By preparing the surface in advance with appropriate hardness distribution (higher at radially outer portion), the design prevents wear and clearance formation that would otherwise occur during operation, thereby maintaining vibration damping performance over time.
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
This approach enhances the abrasion resistance of the retainer's inner surface, maintaining flatness and preventing increased impact loads, ensuring consistent vibration damping performance by allowing the rolling mass to reciprocate smoothly and evenly, thus maintaining the damper's effectiveness over time.
Implementation Method 1
a wall surface of the shaft hole is hardened by high-frequency induction heating through an induction heating coil inserted in the shaft hole
Implementation Method 2
the rolling mass held in the retainer is centrifugally brought into contact to the raceway surface by a rotation of the rotary member
Data Source
AI summary
A torsional vibration damper having improved abrasion resistance at a portion of a rotary member to which a rolling mass is contacted, and a manufacturing method thereof. The torsional vibration damper comprises: a rotary member; an inertia body oscillating around the rotary member; and a retainer formed on the rotary member to hold a rolling mass between a pair of stoppers. A hardness of an inner surface of at least one of the stoppers is increased higher in a radially outer portion than in a radially inner portion, within a reciprocating range of the rolling mass.