Spindle Motor Bearing Structure to Prevent Shaft Wobble
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Solution Overview
Problem
In spindle motors, the attachment screw can cause deformation near the clamp hole, leading to shaft wobbling and displacement of the shaft center.
Innovation Solution
The spindle motor design includes a shaft with a screw hole, a bearing part with upper and lower annular members, and a sleeve that covers the shaft, reducing deformation and shaft wobbling by ensuring proper alignment and fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the attachment screw is screwed into the clamp hole, then the shaft is fixed to the base part, but the vicinity of the clamp hole deforms and the shaft center displaces, resulting in shaft wobbling
Solution Approach 1:
The patent introduces a bearing part as an intermediary component between the shaft and base part. The bearing part includes an upper annular member and a lower annular member that sandwich and fix the shaft, eliminating direct screw fixation to the shaft body. This intermediary structure prevents deformation at the clamp hole while maintaining secure shaft fixation and center alignment.
2Ease of operation
If the clamp hole is used for screw fixation, then the shaft can be secured, but deformation occurs near the clamp hole causing shaft wobbling
Solution Approach 1:
The bearing part serves as a mediator that simplifies shaft installation through a press-fit structure while improving rotational stability. The upper and lower annular members provide stable support for the shaft without requiring clamp holes, eliminating both installation complexity and reliability issues associated with screw fixation.
Solution Approach 2:
The patent extracts the fixation function from the shaft body by moving it to the bearing part. The clamp hole and screw fixation are removed from the shaft, and the fixation function is transferred to the bearing part's press-fit structure, resolving the contradiction between ease of operation and rotational stability.
3Force
If the shaft is fixed using a clamp hole and screw, then the shaft is secured to the base part, but shaft wobbling and vibration occur
Solution Approach 1:
The bearing part acts as an intermediary that maintains strong fixation force through press-fit between the shaft and annular members while eliminating shaft wobbling and vibration. This structure distributes the fixation force evenly around the shaft circumference, preventing the localized deformation and wobbling caused by point fixation at a clamp hole.
Data Source
AI summary
A spindle motor includes a shaft, a base part, a stator core, a rotor, and a bearing part. The shaft extends along a center axis extending in the vertical direction and has a screw hole extending axially downward from the upper end thereof. The screw hole has a screw part onto which a screw is screwed. The bearing part includes an upper annular member, a lower annular member, and a sleeve. The upper annular member and the lower annular member protrude radially outward from an outer peripheral surface of the shaft and are disposed to be spaced apart from each other in the axial direction. The sleeve covers the outer peripheral surface of the shaft, extends in the axial direction, and is defined in a cylindrical shape. The upper end of the upper annular member is disposed lower than the lower end of the screw part in the axial direction.