Compact Planetary Gear Door Closer for Reduced Axial Thickness
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Solution Overview
Problem
Existing door closer devices for vehicles are bulky due to their complex structure, particularly the cylindrical sun gear and disc-shaped ring gear with gear teeth, which increases the device's size and complexity.
Innovation Solution
A compact door closer device design featuring a planetary gear mechanism with a sun gear having external teeth over 170 degrees, a sector gear with internal teeth, and a closing lever that reduces the axial thickness and number of parts, allowing for smoother operation and a smaller footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cylindrical sun gear and disc-shaped ring gear with gear teeth are used to transmit rotational force, then the door closer device can function properly, but the device becomes larger and more complex
Solution Approach 1:
The gear mechanism is segmented into modular components: a sun gear with external teeth, planetary gears with internal teeth, and a ring gear. This segmentation allows each component to be optimized independently and simplifies the overall structure while maintaining reliable rotational force transmission from the motor to the latch mechanism.
Solution Approach 2:
The planetary gear mechanism employs a nested arrangement where planetary gears with internal teeth are positioned within the ring gear structure. This nesting allows multiple gear functions to be integrated into a compact configuration, reducing the overall device size and complexity while preserving the ability to transmit rotational force effectively.
2Reliability
If a cylindrical sun gear and disc-shaped ring gear are used, then rotational force can be transmitted, but the axial thickness and number of parts increase
Solution Approach 1:
The gear arrangement transitions from a conventional two-dimensional disc configuration to a three-dimensional planetary gear system. By stacking planetary gears with internal teeth within the ring gear structure, the design utilizes vertical space more efficiently, reducing the overall axial thickness while maintaining the necessary rotational force transmission path from the motor to the latch.
3Volume of stationary object
If a compact planetary gear mechanism is designed, then the device size is reduced, but the gear structure becomes more complex
Solution Approach 1:
The planetary gear mechanism is designed as a multi-functional system where the sun gear, planetary gears, and ring gear work together to provide both speed reduction and torque multiplication. This universal design allows a single compact mechanism to perform multiple functions, reducing the need for separate components and simplifying the overall structure despite the intricate gear interactions.
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 design achieves a more compact size while maintaining the functionality of moving the latch from a half-latch to a full-latch position, enhancing the door closing mechanism's efficiency and reducing the overall size of the device.
Implementation Method 1
a planetary gear mechanism including a drive lever which rotates together with the carrier. Rotational force from the carrier is transmitted to a latch of a latch mechanism
Data Source
AI summary
A door closer device comprises a sun gear pivotally mounted via a pivot shaft, a planetary gear which meshes with the sun gear to orbit the sun gear while turning on its own axis, a closing lever pivotally mounted via the pivot shaft and pivotally mounted with the planetary gear, and a sector gear which has an external teeth meshing with an output gear and an internal teeth meshing with the planetary gear. The closing lever swings about the pivot shaft to allow a latch to move from a half-latch position to a full-latch position where the latch fully engages with a striker.