Telescoping Propshaft Axial Sliding Mechanism
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Solution Overview
Problem
Existing telescoping propshafts require complex and costly designs with long splined segments to collapse axially, increasing manufacturing expenses and complexity.
Innovation Solution
A propshaft design featuring a universal joint with yoke arms and trunnions, and tubular members with circumferentially spaced teeth, allowing for axial sliding and telescoping without the need for extensive splining, reducing manufacturing costs and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If long splined segments with multiple teeth are used to enable axial telescoping, then the propshaft can collapse to a specified length, but the manufacturing cost and complexity increase
Solution Approach 1:
The propshaft is divided into two separate tubular members (inner and outer tubes) with distinct functions. The inner tube contains a limited number of splines for torque transmission, while the outer tube provides structural support and houses the universal joints. This segmentation allows each component to be optimized independently, reducing overall complexity compared to a single complex splined assembly.
Solution Approach 2:
The invention extracts the torque transmission function from the telescoping mechanism itself. Instead of relying on multiple splined teeth throughout the entire telescoping length, the design uses a separate spline set on the inner tube that engages with the outer tube. This extraction allows the telescoping action to occur with minimal splining, significantly reducing manufacturing complexity while maintaining effective torque transmission.
2Strength
If more teeth are added to the splined segments to ensure adequate torque transmission, then the torsional load capacity improves, but the manufacturing cost increases
Solution Approach 1:
The invention separates the torque transmission function from the telescoping function. A dedicated spline set on the inner tube handles torque transmission with a limited number of teeth, while the telescoping action is achieved through the interaction between the inner and outer tubes. This extraction eliminates the need for numerous teeth throughout the entire telescoping length, reducing manufacturing cost while maintaining adequate torsional load capacity.
Solution Approach 2:
The splines are concentrated in specific localized regions where they are most effective for torque transmission, rather than being distributed uniformly along the entire telescoping length. The inner tube features splines in regions that provide optimal engagement with the outer tube during both extended and collapsed states. This localized placement reduces the total number of teeth required while ensuring adequate strength where it is most needed.
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 design enables efficient telescoping with reduced manufacturing costs and complexity, maintaining effective power transmission across varying lengths while simplifying the production process.
Implementation Method 1
The first tubular member is fixedly coupled to the first yoke and has an exterior surface with a plurality of first tooth sets. The second tubular member has an interior surface with a plurality of second tooth sets. Each second tooth set has one or more second teeth that are meshingly engaged with the one of more first teeth of an associated one of the first tooth sets
Implementation Method 2
The first universal joint has a first yoke, a second yoke and a cross-shaft. The first yoke has a pair of first yoke arms. The second yoke has a pair of second yoke arms. Each of the first trunnions is pivotally mounted to a corresponding one of the first yoke arms. Each of the second trunnions is pivotally mounted to a corresponding one of the second yoke arms
Implementation Method 3
The second tubular member is slidably received over the first tubular member and has an interior surface with a plurality of second teeth. The first and second tubular members are positionable in an extended condition in which the propshaft has a first length and the first and second teeth are engaged to one another such that the first tubular member is rotatably coupled to the second tubular member
Data Source
AI summary
A propshaft with an universal joint, a first tubular member and a second tubular member. The universal joint has first and second yoke arms that are pivotally coupled to one another. The first tubular member is fixedly coupled to the first yoke arms and has a plurality of first teeth. The second tubular member slidably received over the first tubular member and includes a plurality of second teeth. The first and second teeth engage one another when the propshaft is in an extended condition. The second teeth engage the first yoke arms when the propshaft is in a retracted condition.