Disk Drive Base Plate Motor Mount Stiffness Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional disk drive apparatuses face challenges in reducing axial thickness to make them thinner, which weakens the base plate's stiffness, leading to increased vibration, noise, and instability in disk position, causing errors in data reading and writing.
Innovation Solution
A base plate design with a motor base made of a metallic material with a higher Young's modulus than the base body portion, incorporating a bearing mounting portion, bottom plate, wall, flange, and plastic deforming portions to reduce axial thickness while maintaining stiffness, and preventing motor base extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the axial thickness of the base plate is reduced to make the disk drive apparatus thinner, then the axial thickness is reduced, but the stiffness of the base plate is weakened
Solution Approach 1:
The base plate employs different materials with different Young's moduli in different regions. The motor base portion uses a material with higher Young's modulus (first type) while the base body portion uses a material with lower Young's modulus (second type). This local differentiation allows the motor base to maintain high stiffness for vibration reduction while the overall base plate thickness is reduced.
Solution Approach 2:
The base plate is constructed as a composite structure combining two different metallic materials. The motor base portion and base body portion are made of different materials with different mechanical properties, creating a composite base plate that optimizes both stiffness and thickness. This composite approach enables the thin design while maintaining necessary structural rigidity.
2Length of moving object
If the axial thickness of the base plate is reduced, then the axial thickness is reduced, but vibration and noise due to motor driving are increased
Solution Approach 1:
The motor base portion is specifically designed with a material having higher Young's modulus to locally enhance stiffness where the motor is mounted. This localized stiffening reduces vibration and noise generated by motor operation while allowing the rest of the base plate to be thinner.
Solution Approach 2:
By combining materials with different Young's moduli in a composite base plate structure, the motor base portion provides superior vibration resistance while the overall thickness is reduced. The composite construction allows the stiffer material to be positioned precisely where vibration control is most critical.
3Length of moving object
If the axial thickness of the base plate is reduced, then the axial thickness is reduced, but the position of the disk becomes unstable
Solution Approach 1:
The motor base portion with higher Young's modulus material provides localized structural support and stability. This stiffer region anchors the motor and disk assembly, maintaining positional stability even when the overall base plate thickness is reduced.
Solution Approach 2:
The composite base plate structure with differentiated material properties provides enhanced structural integrity at the motor mounting region. This ensures the disk position remains stable while allowing the base plate to be thinner overall.
4Length of moving object
If the axial thickness of the base plate is reduced, then the axial thickness is reduced, but errors in reading and writing of data easily occur
Solution Approach 1:
The motor base portion with higher stiffness reduces vibrations that could cause read/write errors. By concentrating the stiffer material where the motor and data operations occur, the design protects against errors while maintaining thin overall dimensions.
Solution Approach 2:
The composite base plate provides enhanced vibration resistance and structural stability in the critical motor region, reducing the likelihood of read/write errors while enabling a thinner form factor that improves overall device reliability.
Data Source
AI summary
A base plate of a disk drive apparatus includes a motor base disposed around a central axis and a base body portion extending radially outward of the motor base. The motor base is made of a metallic material of a first type. The base body portion is made of a metallic material of a second type. Thus, the axial thickness of a portion of the base plate close to the central axis can be significantly reduced and a reduction in the stiffness of the portion can be prevented. Further, the motor base includes a flange portion and a plastic deforming portion. The flange portion and the plastic deforming portion are respectively in contact with at least a portion of both axial end surfaces of an inner end portion of the base body portion. Thus, extraction of the motor base in the axial direction is prevented.