Foldable Hinge Transmission Using Bevel Gears to Eliminate Gear Lag
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Solution Overview
Problem
Foldable mobile phones experience gear rotation lag due to large gear moment tolerances in synchronous transmission gearsets, affecting the synchronous rotation of main-body parts, which is not effectively addressed by existing pivot mechanisms.
Innovation Solution
A foldable apparatus with a rotating shaft base, main bodies, and a synchronous transmission assembly featuring combined-gears with second bevel gears and spur gears that engage to ensure synchronous rotation, reducing gear lag by eliminating center distance tolerance between bevel gears.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a synchronous transmission gearset with multiple gears in the same rotation plane is used, then the main-body parts can be driven to rotate relative to each other, but gear moment tolerances are large causing gear rotation lag
Solution Approach 1:
The patent transitions from a traditional gear arrangement where multiple gears share the same rotation plane to a configuration where bevel gears are positioned at different spatial locations and orientations. Specifically, the first bevel gear is disposed on the first rotating member and the second bevel gear is disposed on the second rotating member, with their rotation axes intersecting or being parallel. This dimensional repositioning in three-dimensional space eliminates the gear rotation lag issue by distributing gears across different spatial dimensions rather than confining them to a single plane.
2Ease of operation
If traditional spur gears and conical gears are engaged to transmit power, then the dual-shaft hinge can rotate, but center distance tolerance exists affecting rotation precision
Solution Approach 1:
The patent introduces a novel transmission mechanism using bevel gears as an intermediary between the first and second rotating members. The first bevel gear and second bevel gear engage with each other through their conical tooth surfaces, creating a precise angular power transmission path. This bevel gear intermediary eliminates the center distance tolerance problem that plagues traditional spur gear arrangements, as bevel gears naturally accommodate angular relationships while maintaining precise meshing through their conical geometry and intersecting or parallel rotation axes.
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 solution enables precise and synchronous rotation of main bodies around the rotating shaft base, effectively addressing gear lag and improving the folding/unfolding mechanism of foldable electronic devices like mobile phones and tablets.
Implementation Method 1
two second bevel gears engage with two first bevel gears respectively
Implementation Method 2
two spur gears engage with each other
Data Source
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AI summary
A foldable apparatus and an electronic device are provided in the present disclosure. The foldable apparatus includes a rotating shaft base, two main bodies disposed at two opposite sides of the rotating shaft base, and a synchronous transmission assembly connected with the two main bodies. Each main body is provided with a rotating member rotatably connected with the rotating shaft base and a housing fixedly connected with the rotating member. Each rotating member is provided with a first bevel gear at an end. The synchronous transmission assembly includes two combined-gears rotatably connected with the rotating shaft base, each combined-gear includes a second bevel gear and a spur gear coaxial with the second bevel gear, two second bevel gears engage with two first bevel gears respectively, and two spur gears engage with each other. The rotating member drives a rotating member at another side to synchronously rotate through the synchronous transmission assembly, thus the two main bodies can synchronously rotate around the rotating shaft base.