Vehicle Parking Device Worm Gear Actuator Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle parking systems for automatic transmissions face issues with high operating force due to frictional resistance and sudden shock or vibration when engaging or disengaging the parking mode, leading to instability and inaccuracy in the parking process.
Innovation Solution
A vehicle parking device and transmission system that incorporates an actuator to rotate a worm gear, a loading unit with a rack gear and elastic members to linearly move and rotate a parking sprag, which is selectively engaged with a parking gear, allowing for precise and stable engagement and disengagement without energy loss, using a combination of compressive and repulsive forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the parking gear and parking sprag are engaged using the related art parking system, then the parking mode is achieved, but a large operating force is generated due to frictional resistance
Solution Approach 1:
The parking device is divided into separate functional modules: the loading unit that applies force to the parking sprag, the parking sprag that engages with the parking gear, and the actuator that drives the worm gear. This segmentation allows the loading unit to independently apply controlled force, reducing the overall operating force required while maintaining reliable engagement.
Solution Approach 2:
The loading unit acts as an intermediary between the actuator and the parking sprag. It includes a loading ball that contacts the parking sprag and applies force through a loading groove, mediating the force transmission to reduce frictional resistance during engagement while ensuring stable parking mode.
2Productivity
If the parking mode is released suddenly by ignoring the frictional resistance, then the parking mode is disengaged, but shock or vibration is generated
Solution Approach 1:
The loading unit is designed with elastic elements and a loading groove that gradually apply and release force on the parking sprag. This beforehand cushioning ensures that the parking sprag is smoothly engaged and disengaged from the parking gear, preventing sudden shocks and vibrations while maintaining efficient mode switching.
Solution Approach 2:
The parking sprag is designed to rotate dynamically around its axis as it engages and disengages with the parking gear. The loading unit applies variable force through the loading groove, allowing the parking sprag to smoothly transition between engaged and disengaged states, reducing shock and vibration during mode switching.
3Reliability
If the parking sprag is rotated by linear movement of the loading unit, then the parking gear is selectively engaged, but the contact surface between the parking gear and parking sprag generates frictional resistance
Solution Approach 1:
The loading unit features a loading groove with a specific curvature that concentrates and directs force locally on the parking sprag at the optimal engagement point. This local quality optimization ensures accurate engagement between the parking gear and parking sprag while minimizing the contact area and frictional resistance.
Solution Approach 2:
The loading groove is designed with specific geometric parameters (curvature radius, angle, and position) that optimize the force application point on the parking sprag. By changing these parameters, the system achieves reliable engagement with reduced frictional resistance and minimal energy loss.
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 system enables precise and stable implementation of the parking mode with reduced energy loss, preventing secondary release and allowing for easy assembly and maintenance, while reducing the number of parts and system volume compared to existing solutions.
Implementation Method 1
a first elastic member inserted into the support shaft and in contact with the rack gear. The rack gear may linearly move according to a rotation of the worm gear, receive a compressive force from the first elastic member, and linearly move together with the housing to rotate the parking sprag.
Implementation Method 2
an actuator configured to rotate a worm gear mounted at an end thereof, a loading unit including a rack gear engaged with the worm gear and linearly moving according to a movement of the rack gear
Implementation Method 3
The parking sprag may include a body, a protruding end arranged at an end of the body and inserted into the parking gear, and an inclined end arranged so that a portion of the loading unit is inserted thereinto, the inclined end being in surface contact with the inclined surface of the loading unit.
Data Source
AI summary
Provided are a vehicle parking device and a vehicle transmission. The vehicle parking device includes an actuator configured to rotate a worm gear mounted at an end thereof, a loading unit including a rack gear engaged with the worm gear and linearly moving according to a movement of the rack gear, a parking sprag in contact with the loading unit and rotating by a linear movement of the loading unit, and a parking gear provided in a drive shaft that transmits a driving force and selectively engaged according to a rotation of the parking sprag.