Motor Rotor Retaining Mechanism for Thin Drive Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotor retaining mechanisms in data storage medium drives, such as the shaft retaining and hook-shaped types, face challenges in reducing the thickness of spindle motors while maintaining rotational stability and preventing deformation of the turntable, which is crucial for achieving thinner data storage medium drives.
Innovation Solution
A rotor retaining mechanism featuring a retaining claw with a slanted surface on the housing and a retaining member with a planar attachment base and axially projecting arms, which restricts the upward movement of the turntable and minimizes deformation by distributing the load effectively, allowing for a thinner design without compromising stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional shaft retaining mechanism is used, then the rotor is prevented from coming off, but the shaft must be extended which increases the thickness of the spindle motor
Solution Approach 1:
The invention transitions from axial retention (shaft extending axially) to radial retention (retaining member extending radially from the housing). The retaining member protrudes radially inward into the groove on the shaft, preventing rotor removal without requiring axial extension of the shaft, thus resolving the contradiction between rotor retention reliability and shaft length.
2Length of moving object
If a hook-shaped retaining mechanism is used, then the thickness is reduced, but the turntable may deform under load or impact
Solution Approach 1:
The retaining mechanism is segmented into two functional parts: the groove on the shaft (providing retention) and the retaining member on the housing (providing structural support). This segmentation allows the turntable to remain thin and stable while the retaining function is distributed between these two components, resolving the contradiction between reduced thickness and maintained stability.
3Length of moving object
If the turntable thickness is reduced to achieve thinner drives, then the motor thickness is reduced, but the rigidity of the turntable is lowered making it susceptible to deformation
Solution Approach 1:
The retaining member extends partially into the groove (not fully through it), providing sufficient retention force to prevent rotor removal while minimizing interference with the turntable structure. This partial action allows the turntable to maintain thinness and rigidity while still achieving effective rotor retention through the cooperating groove-retaining member interface.
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 solution enables a significant reduction in the thickness of data storage medium drives while maintaining rotational accuracy and preventing deformation, thus enhancing the portability and efficiency of portable computers.
Implementation Method 1
The retaining member has a planar attachment base and a plurality of retaining portions. Each retaining portion is arranged with an arm projecting axially downward, and a catching portion which is arranged at the lower side of the arm and comes into contact with the retaining claw.
Implementation Method 2
The retaining claw of the housing is arranged with a slanted surface that slants axially downward to the radially outer side. The slanted surface contacts the retaining member while the rotor is being mounted to the housing.
Data Source
AI summary
In a motor, a retaining claw with a slanted surface is arranged around the upper end of a tubular portion of a housing for mounting a rotor. A cylindrical portion is integrally formed in a peripheral area of a rotational axis of a turntable. A retaining member with retaining portions having a J-shaped cross section is attached to the lower surface of the turntable. Arms of the retaining portions are located in the vicinity of the lower end of the cylindrical portion. In mounting the rotor onto the housing, the retaining portions contact the slanted surface and the arms are elastically deformed. Upon completion of the mounting, the arms return to a state before the elastic deformation, so that the retaining claw prevents the rotor from coming off.