Valve Stem Retainer Assembly Guide Member Stabilization
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Solution Overview
Problem
Existing retainer assembling techniques for valve stems often result in engagement failures due to unstable postures of cotter segments, particularly when the cotter segments turn over or have non-uniform orientations, leading to complications in the assembly process.
Innovation Solution
A retainer assembling apparatus that includes a holding unit with a guide member having a tapered inner surface to stabilize the cotter segments and a contact member to maintain their separated state, ensuring consistent orientation and preventing engagement failures by guiding and tapping the cotter segments into a stable position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If only a retainer hole supports the pushed-up cotter segments, then the apparatus structure is simple, but the cotter segments have unstable postures leading to engagement failure
Solution Approach 1:
A guide member is introduced as an intermediary component between the retainer hole and the cotter segments. The guide member has a guide hole through which the cotter segments pass, providing intermediate support and guidance to stabilize their postures during the engagement process, thereby preventing engagement failure while maintaining relatively simple apparatus structure
Solution Approach 2:
The guide member extends in the axial direction of the retainer, adding a dimensional element that provides lateral support to the cotter segments. This axial extension creates a three-dimensional guidance structure that constrains the cotter segments' movement and stabilizes their orientation during engagement
2Reliability
If a holding mechanism is arranged to stabilize the cotter segments, then the postures of the cotter segments are stable, but the apparatus arrangement becomes complicated
Solution Approach 1:
The guide member serves multiple functions: it guides the cotter segments during insertion, stabilizes their postures, and maintains their separated state. By combining these functions into a single component rather than using separate holding mechanisms, the apparatus achieves reliable cotter segment stabilization without increasing overall structural complexity
Solution Approach 2:
The guide member's tapered inner surface automatically stabilizes the cotter segments through its geometric shape alone, without requiring additional active holding mechanisms. The taper geometry self-regulates the cotter segment orientation through passive mechanical guidance
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 apparatus effectively stabilizes the postures of cotter segments, preventing engagement failures and simplifying the assembly process by ensuring consistent alignment and separation of cotter segments during the assembly of the retainer to the valve stem.
Implementation Method 1
a guide member (113) having a guide hole (113a), and a tapered inner circumferential portion (113b)
Implementation Method 2
a contact member (17) which contacts the cotter segments (71) from above the cotter segments (71)
Data Source
Figure 1
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AI summary
A retainer assembling apparatus assembles a retainer (5) to a valve stem via a cotter which engages with an engaging groove formed on the valve stem and which has a pair of cotter segments (71). The apparatus includes a cylindrical body (11), a holding portion (152) which holds the retainer (5) contacting a lower end of the cylindrical body (11), a push-up shaft (31) which pushes up the pair of cotter segments (71) into the cylindrical body (11), and an axial body which is arranged in the cylindrical body (11) to be coaxial with the push-up shaft (31) and to be coaxially movable. The cylindrical body (11) includes a tapered inner circumferential portion on an inner circumferential wall lower portion thereof.