Sealed Spherical Joint With Motion Limiter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Spherical joints in motor graders require frequent maintenance due to grease lubrication, which can lead to internal damage and reduced sealing effectiveness, necessitating a design that minimizes maintenance and maintains sealing integrity.
Innovation Solution
A spherical joint design featuring a socket, ball stud, and seal, where the socket and ring retainer cooperate to limit relative movement, preventing contact between the retainer and seal, and utilizing low friction materials to reduce wear, thus eliminating the need for grease and minimizing maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If grease lubrication is used in the spherical joint, then the joint can operate smoothly, but frequent maintenance is required to replenish lubricant
Solution Approach 1:
The patent extracts and eliminates the grease lubrication system from the spherical joint, replacing it with a dry friction-based design using spherically mated surfaces with low friction coefficients. This removes the need for lubricant replenishment and associated maintenance time while maintaining smooth operation through the inherent low-friction spherical contact between the ball stud and socket.
Solution Approach 2:
The spherical joint design allows the joint to self-lubricate through the low friction materials and spherical geometry itself, without requiring external grease application. The design serves its own lubrication needs through the inherent properties of the mated spherical surfaces, eliminating the need for periodic maintenance interventions.
2Strength
If the ring retainer is positioned to retain the inner ring, then the inner ring is secured to the shaft, but the retainer may contact the seal causing damage
Solution Approach 1:
The patent segments the retention function from the sealing function by introducing a dedicated motion limiter component that is separate from the ring retainer. The ring retainer focuses solely on securing the inner ring to the shaft with strong retention, while the separate motion limiter prevents excessive movement that would cause the retainer to contact and damage the seal, thus protecting seal integrity.
Solution Approach 2:
The motion limiter acts as an intermediary element between the ring retainer and the seal. It mediates the interaction by limiting the relative movement of the ball stud and socket, thereby preventing the ring retainer from making contact with the seal while still allowing the retainer to perform its retention function effectively.
3Adaptability or versatility
If relative movement between socket and ball stud is unrestricted, then the joint has full range of motion, but wear increases and maintenance is required
Solution Approach 1:
The patent applies partial action by implementing a motion limiter that restricts the range of motion to a specific subset of possible movements. Instead of allowing full unrestricted motion, the limiter permits only those movements necessary for normal operation while preventing excessive movements that would cause wear and contact between the ring retainer and seal, thus improving wear resistance while maintaining adequate adaptability.
Data Source
AI summary
A spherical joint comprises a socket, a ball stud, and a seal. The ball stud comprises a shaft, an inner ring positioned within an outer ring of the socket and within which the shaft is positioned, and a ring retainer attached to the shaft and retaining the inner ring to the shaft. The ring retainer provides an axial end of the ball stud relative to the axis. The outer ring and the inner ring comprise respectively a first spherical surface and a second spherical surface. The first and second spherical surfaces spherically mate with one another. The seal establishes a sealed connection between the outer ring and the inner ring. The socket and the ring retainer cooperate to provide a motion limiter that limits relative movement between the socket and the ball stud so as to prevent contact between the ring retainer and the seal.