Disk Clamp Structure for Stable Head Levitation
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Solution Overview
Problem
Conventional disk apparatuses face challenges in achieving stable head levitation and preventing contact between the head and disk due to deformation and warping caused by clamping, especially in mobile equipment where shock resistance and data density are critical, and the existing solutions either compromise on shock resistance or increase repetitive runout.
Innovation Solution
A disk apparatus with a clamp structure that includes a hub with a disk receiving portion having an inclined or declined plane, a clamp unit with multiple screw threads, and a spacer ring, where the distances Rh and Rs are carefully managed to control the warp and levitation, ensuring the disk is convex with respect to the head, thereby maintaining stable head levitation and preventing contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the axial force of screw thread is increased to prevent disk shift due to shock, then shock resistance is improved, but repetitive runout of disk is increased due to clamping force
Solution Approach 1:
The clamp structure is divided into multiple functional components: hub, clamp member, and screw thread assembly. The hub provides structural support and positioning, the clamp member applies clamping force through its pressing surface, and the screw thread assembly provides adjustable axial force. This segmentation allows optimization of each component's function to balance shock resistance and runout prevention
Solution Approach 2:
The clamp member is designed with a pressing surface that has a specific area and pressure distribution characteristic. By controlling the local quality of the pressing surface (its area and orientation), the clamping force is distributed appropriately to prevent disk shift during shock while minimizing deformation that causes repetitive runout
2Reliability
If the clamping force is increased to improve shock resistance, then disk shift is prevented, but the center axis alignment between clamp member and hub becomes more difficult to maintain
Solution Approach 1:
The clamp member is designed with asymmetric features including an inclined or declined pressing surface rather than a purely symmetric flat surface. This asymmetric design allows the clamp member to self-align with the hub's center axis under clamping load, maintaining precise alignment even when high clamping forces are applied to prevent disk shift during shock
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 stabilizes head levitation, reduces deformation, and enhances shock resistance, allowing for a decrease in thickness and an increase in data capacity while maintaining reliable data reading and writing operations.
Implementation Method 1
the axial force of screw thread 4
Implementation Method 2
Disk 1 is integrally fixed to hub 2 by the frictional force of the contacts of the members
Data Source
AI summary
A disk apparatus includes a hub having a disk inserting portion having a cylindrical plane in the outer part of one end and a disk receiving portion having a flat part and being pivotably supported, a head having an inner hole through which the disk inserting portion is fitted, facing toward one face of a disk, levitating and scanning above the disk and reading a signal recorded on the disk or recording a signal on the disk, the disk being held by the disk receiving portion, and a clamp unit holding the disk with the disk receiving portion. In this case, the disk receiving portion has an inclined or declined plane. Thus, the amount and direction of deformation of the disk, which is caused by clamping, are defined, and obtaining a stable amount of head levitation independently of temperature changes can prevent the occurrence of a distortion of the disk.