Dial-Type Vehicle Transmission With Eccentric Gearing and Quiet Park Return
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Solution Overview
Problem
Existing vehicle transmissions face challenges in minimizing size while maintaining a high gear ratio and reducing detent noise during automatic return to the park stage, particularly due to interference between accessory components and the generation of unpleasant noise from the detent unit.
Innovation Solution
A vehicle transmission design that incorporates a dial type gear shift operation, where a gear unit rotates about the same axis as a knob and another gear unit rotates about a different axis, allowing for a high gear ratio without substantial diameter differences, and deactivates the detent unit during automatic return to the park stage to minimize noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional mechanical transmission is used with a linear shift lever, then the driver can easily operate the gear shift, but the space required for the shift lever movement locus increases, reducing spatial utilization
Solution Approach 1:
The patent transitions from a linear shift lever movement to a rotary dial-type operation. The shift lever is configured to rotate about a rotational axis, converting linear displacement into rotational motion. This dimensional change allows the gear shift operation to occur within a compact circular path rather than requiring a large linear space, thereby improving spatial utilization while maintaining ease of operation
Solution Approach 2:
The patent employs a dial-type gear shift operation where the shift lever rotates dynamically about a rotational axis. The movable plate rotates in response to the rotational input, and the gear units (including the first external gear, second external gear, and ring gear) rotate to change gear ratios. This dynamic rotary mechanism provides intuitive operational feedback to the driver while occupying minimal space
2Productivity
If a high gear ratio is achieved using conventional gear arrangements, then the transmission efficiency improves, but the diameter difference between gear units increases, leading to larger overall transmission size
Solution Approach 1:
The patent implements a nested gear arrangement where the first external gear is eccentrically engaged with the internal gear, the second external gear is engaged with the first external gear, and the ring gear surrounds the second external gear. This nested configuration allows multiple gear units to occupy overlapping spatial volumes, achieving a high gear ratio through compounded rotational reductions without requiring proportionally large diameter differences between individual gear units, thereby minimizing the overall transmission size
Solution Approach 2:
The patent utilizes eccentric engagement between gear units, where the first external gear is offset from the center of the internal gear, and the second external gear is offset from the center of the first external gear. This eccentric arrangement introduces a radial dimension to the gear transmission, allowing the gear units to rotate about different centers while maintaining compact overall dimensions. The rotational axes are offset, creating a multi-dimensional gear train that achieves high reduction ratios without increasing the footprint
3Reliability
If the detent unit is activated during automatic return to park stage, then the shift lever can be securely positioned, but detent noise is generated, creating an unpleasant driving experience
Solution Approach 1:
The patent implements a control unit that periodically activates and deactivates the detent unit based on the operational stage. During automatic return to park, the control unit deactivates the detent unit to prevent noise generation. Once the shift lever reaches the park position, the control unit reactivates the detent unit to secure the position. This periodic control strategy eliminates detent noise during the return operation while maintaining reliable positioning when needed
Solution Approach 2:
The patent employs a feedback mechanism where the control unit monitors the position and operational state of the shift lever. Based on this feedback, the control unit determines when to activate or deactivate the detent unit. During automatic return to park, the feedback signal indicates motion is in progress, so the detent unit remains deactivated. When the park position is detected, the feedback triggers detent unit activation to lock the position, thereby preventing noise during operation while ensuring secure positioning
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 design enhances spatial utilization within the vehicle, achieves a high gear ratio with reduced overall size, and eliminates detent noise during automatic return to the park stage, improving the driving experience by reducing unnecessary operation feelings and noise.
Implementation Method 1
a first external gear eccentrically engaged with the internal gear and a second external gear that rotates when meshing with the ring gear
Implementation Method 2
an eccentric gear unit that has a first external gear eccentrically engaged with the internal gear
Data Source
AI summary
Provided is a vehicle transmission for a gear shift operation. The vehicle transmission includes: a shift lever which is at least partially displaced toward front or rear directions by a driver to select shift stages; a movable plate which includes an input shaft rotated according to the displacement of the shift lever and an internal gear; an eccentric gear unit which has a first external gear eccentrically engaged with the internal gear and a second external gear moved simultaneously with the first external gear; a rotation unit having a ring gear with which the second external gear is eccentrically engaged; and an insertion unit which includes an eccentric shaft inserted into an aperture formed at a center of the eccentric gear unit and a central shaft formed with the eccentric shaft and inserted into an aperture formed at a center of the rotation unit.