Rotational Coupling Key Retention via Complementary Shaping
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Solution Overview
Problem
Conventional rotational coupling devices face challenges in retaining the drive key during shipping, assembly, and operation, leading to misalignment and increased maintenance costs due to the key's tendency to travel relative to the rotor and input shaft.
Innovation Solution
The rotational coupling device features a key and support member shaped in a complementary fashion to limit radial and axial movement of the key, ensuring it remains in place during shipping, assembly, and operation, thereby reducing assembly time and maintenance costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate key component is used to couple the rotor and input shaft, then the coupling function is achieved, but the key tends to travel relative to the rotor and input shaft during assembly and operation
Solution Approach 1:
The key is divided into two functional segments: a drive key portion that engages with the rotor and input shaft keyways, and a retained key portion that is captured by the support member. This segmentation allows the key to fulfill its coupling function while preventing unwanted movement through the support member's retention structure.
Solution Approach 2:
The retained key portion is nested within the support member's key retention structure. The support member receives and holds the retained key portion, creating a nested configuration that secures the key in place while allowing the drive key portion to perform its coupling function.
2Productivity
If the key is inserted into opposed keyways during assembly, then the rotor is coupled to the input shaft, but positioning the key at the proper orientation is difficult and consumes assembly time
Solution Approach 1:
The support member is pre-configured with the key retention structure before assembly. This preliminary preparation ensures that when the key is inserted, the retained key portion is automatically captured and positioned correctly by the support member, eliminating the need for precise manual positioning during assembly.
Solution Approach 2:
The support member acts as an intermediary between the key and the rotor/input shaft assembly. It facilitates the assembly process by providing a guided path and retention mechanism that automatically positions the key correctly, reducing the skill and time required for proper key installation.
3Reliability
If the key is retained by the support member with complementary shaping, then radial and axial movement is limited, but the device complexity increases
Solution Approach 1:
The support member serves multiple functions: it provides structural support for the rotor assembly and simultaneously retains the key through its complementary-shaped key retention structure. This multi-functionality reduces the need for separate retention components, thereby limiting the increase in device complexity while maintaining reliable key retention.
Data Source
AI summary
A rotational coupling device for use as a clutch and/or brake is provided with improved retention of a drive key during shipping, assembly, and operation of the device. The device includes a rotor disposed about an input shaft. The input shaft is disposed about a rotational axis and the rotor and input shaft define opposed keyways. A key is disposed in the keyways and rotatably couples the rotor and input shaft. An armature is disposed about the axis and coupled to an output member and configured for selective engagement with the rotor. In one embodiment, the key and a support member in the device are shaped in a complementary fashion to limit radial and axial movement of the key. In another embodiment, an axial end of the key or rotor is deformed to axially align the axial ends of the key and rotor and limit axial movement of the key.