Dual-Friction Hinge Shaft Structure for High Torque and Low Vibration
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Solution Overview
Problem
Existing hinge mechanisms in electronic devices, such as laptop PCs, face challenges in generating sufficient rotational torque while maintaining a small diameter and preventing vibration between chassis, particularly in configurations where a leaf spring or curled bracket generates sliding resistance, which complicates manufacturing and increases the risk of vibration.
Innovation Solution
A hinge device with a shaft pivotally supported by a bearing, featuring a first torque application unit applying frictional force to the shaft's peripheral surface and a second torque application unit applying force in the axial direction, sharing rotational torque to generate sufficient torque without needing large diameters, thus reducing vibration and simplifying manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a leaf spring is interposed between a bracket and a shaft to generate sliding resistance, then rotational torque can be generated, but the diameter becomes larger which is not desirable for further thinning of the electronic apparatus
Solution Approach 1:
The torque application mechanism is divided into two separate units: a first torque application unit that applies frictional force to the peripheral surface of the shaft, and a second torque application unit that applies frictional force to the shaft in the axial direction. This segmentation allows each unit to contribute to torque generation independently, enabling sufficient total torque with smaller individual components, thus reducing the overall diameter.
Solution Approach 2:
The second torque application unit applies frictional force in the axial direction rather than only in the radial direction. This dimensional change in force application allows torque generation without increasing the radial diameter, as the axial force component contributes to torque through the shaft's rotation.
2Force
If one end of a bracket fixed to a chassis is curled and wound around a shaft of a hinge to generate sliding resistance, then rotational torque can be generated, but the curled portion needs to be long in the axial direction and require high straightness of the shaft portion, which makes manufacturing difficult
Solution Approach 1:
The torque generation function is segmented into two separate units with different mechanisms. The first torque application unit uses a simple fitting structure that applies friction to the peripheral surface, while the second applies axial friction. This segmentation eliminates the need for complex curled portions and high-precision shaft straightness requirements, significantly simplifying manufacturing.
Solution Approach 2:
The invention changes the parameters of torque generation by using friction-based mechanisms instead of elastic deformation of curled portions. This parameter change from elastic mechanics to friction mechanics allows for more relaxed manufacturing tolerances and simpler production processes.
3Force
If one end of a bracket fixed to a chassis is curled and wound around a shaft of a hinge to generate sliding resistance, then rotational torque can be generated, but the curled portion is elastic and vibration is likely to occur between the two chassis
Solution Approach 1:
The elastic curled portion that causes vibration is extracted and replaced with friction-based torque application units. The first torque application unit fits around the shaft periphery and the second applies axial friction, both providing stable torque generation without the elastic deformation that leads to vibration between chassis.
Solution Approach 2:
The invention replaces the elastic curled portion with simpler friction-based components that do not rely on elastic recovery. This substitution eliminates the vibration problem associated with elastic materials while maintaining torque generation functionality.
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
The hinge device achieves sufficient torque generation with a smaller diameter, reduces vibration, and facilitates easier manufacturing by distributing torque through multiple application units, allowing for a more compact and stable operation of the electronic apparatus.
Implementation Method 1
a first torque application unit configured to apply a frictional force to a peripheral surface of the shaft by fitting the shaft to the first torque application unit
Implementation Method 2
a second torque application unit configured to apply a frictional force to the shaft in an axial direction
Data Source
AI summary
A hinge device includes a shaft that is pivotally supported by a bearing portion and is rotatable, a first torque application unit configured to apply a frictional force to a peripheral surface of the shaft by fitting the shaft to the first torque application unit, and a second torque application unit configured to apply a frictional force to the shaft in an axial direction. The second torque application unit includes a flange that is formed on the shaft and abuts onto one end of the bearing portion, and a nut that is screwed to a male screw portion of the shaft and is tightened to the other end of the bearing portion via washers and a disc.