Selectable One-Way Clutch Tapered Outer Shell Alignment
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Solution Overview
Problem
The existing selectable one-way clutch designs, such as those described in Japanese Patent Application Publication No. 2002-514292 A, suffer from axial center displacement due to manufacturing tolerances, affecting durability and silence properties.
Innovation Solution
The design incorporates a first plate with a claw that meshes with a recessed portion on a second plate, a selector plate to change the claw's state, and an outer shell with a tapered inner periphery to align the axial centers, allowing increased tolerance and converting impact energy into kinetic energy, along with a biasing member to facilitate easy return and reduce impact forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the claw meshes with the recessed portion and the two plates are joined to each other, then torque transmission is enabled, but axial centers of the two plates are displaced due to manufacturing tolerances
Solution Approach 1:
The outer shell acts as an intermediary alignment mechanism between the first plate and second plate. Its tapered inner periphery makes contact with the outer periphery of the first plate during joining, providing a mechanical guide that reduces axial center displacement caused by manufacturing tolerances.
Solution Approach 2:
The tapered shape of the outer shell's inner periphery changes the geometric parameters of the joining process. By using a conical surface instead of a cylindrical one, the design allows for self-alignment during the joining motion, converting radial play into axial alignment.
2Reliability
If the claw meshes with the recessed portion, then the plates are joined, but impact force is generated due to axial center displacement
Solution Approach 1:
The tapered outer shell provides beforehand cushioning by gradually guiding the first plate into alignment with the second plate during the joining motion. This gradual alignment process cushions the impact that would otherwise occur from sudden meshing due to axial misalignment.
3Ease of manufacture
If manufacturing tolerance is increased to reduce displacement, then allowable range of displacement is enlarged, but alignment precision decreases
Solution Approach 1:
The outer shell serves as a mediator that compensates for increased manufacturing tolerances. By providing a tapered alignment surface, it ensures that even parts with larger tolerance ranges can be properly aligned during assembly, maintaining alignment precision despite relaxed manufacturing constraints.
Data Source
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AI summary
A selectable one-way clutch (1A) includes a first plate (2) and a second plate (3), a claw (11), a selector plate (4) and an outer shell (5). The second plate is placed on the same axis (Ax) as the first plate. The second plate has a recessed portion (15). The claw is provided in the first plate and meshes with the recessed portion in a state where the claw projects from the first plate only when the second plate rotates in a predetermined direction. The selector plate is placed between the first plate and the second plate. The selector plate changes a state of claw. The outer shell covers an outer periphery (21) of the first plate. The outer periphery of the first plate and an inner periphery (20) of the outer shell have a tapered shape in which a diameter is gradually reduced toward a direction distance from the second plate.