Split Hub Pinch Bolt Attachment for Serviceable Shaft Connection
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Solution Overview
Problem
Existing attachment means between a rotating shaft and a hub, such as in pulleys or gears, face challenges in being both serviceable and resistant to wear, with press fits being non-serviceable, splines prone to joint motion wear, and tapered connections being sensitive to load relaxation.
Innovation Solution
A split hub with axially extending relief cuts and complementary flats on both the hub and shaft, along with a threaded fastener through smooth radial bores, provides a secure and easily removable connection by engaging parallel and arcuate surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a press fit connection is used, then the connection is simple and inexpensive, but the components are not easily separated
Solution Approach 1:
The hub is divided into two separate halves (first and second hub halves) that can be independently removed from the shaft, allowing the connection to be easily separated without damaging components while maintaining a simple press-fit-like assembly process
2Ease of repair
If interengaging splines are used, then the components are easily serviced, but the joint is subject to wear due to joint motion
Solution Approach 1:
The hub halves are designed to be dynamically removable and reconfigurable along the shaft, allowing easy serviceability while the friction fit and clamp mechanism minimize relative motion and wear during operation
3Reliability
If a keyed joint is used, then the connection is serviceable and wear resistant, but production assembly is complicated
Solution Approach 1:
The hub is segmented into two halves that can be independently assembled onto the shaft, simplifying production assembly while maintaining serviceability and wear resistance through the clamp-based securing mechanism
Solution Approach 2:
Different regions of the hub halves have different functions: one surface provides friction fit for secure attachment, while the other surface engages with the clamp mechanism for easy removal, optimizing both reliability and ease of assembly
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
This configuration ensures a positive, secure, and easily disassembled connection that reduces wear and facilitates easy removal, suitable for various power carrying components in both stationary and rotating applications.
Implementation Method 1
The clamp members include opposed, parallel flats on the inside of the shaft opening which engage complementarily configured flats on the shaft
Implementation Method 2
A threaded fastener such as a bolt extends through smooth radial bores in one clamp member and the shaft and into a complementarily threaded bore in the other clamp member
Data Source
AI summary
The present invention provides an assembly for attaching a hub to a shaft. The hub, which may be a portion of a gear, pulley, chain sprocket or other power carrying device, includes a collar or annular wall having two axially extending relief cuts on opposite sides of a shaft opening, which define a pair of opposed projections or clamp members. The clamp members include opposed flats on the inside of the shaft opening which engage complementarily configured flats on the shaft. A threaded fastener such as a bolt extends through smooth radial bores in one clamp member and the shaft and into a complementarily threaded bore in the other clamp member. The internal flats of the hub include opposed arcuate, axially extending reliefs. The outside surface of the hub proximate the smooth bore defines a chordal surface which the bolt engages.