Universal Driving Device for Reducing Unsprung Mass
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Solution Overview
Problem
Existing driving devices face durability issues due to severe impact and vibration, and ride comfort problems caused by increased unsprung mass, and they struggle with continuous power transmission during vertical wheel movement without using constant velocity joints, which limits their application in vehicles.
Innovation Solution
A universal driving device featuring a sun gear, ring gear, and multiple gear trains with balance gears that allow relative motion between the sun and ring gears, maintaining continuous power transmission and reducing unsprung mass by separating the motor from the wheel, thus improving durability and ride comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a motor is directly installed in the driving wheel (in-wheel motor system), then the space between power source and wheel is reduced, but the unsprung mass increases causing ride comfort problems
Solution Approach 1:
The driving device is divided into two separate parts: the power source (motor) is installed in the vehicle body, while the driving device including sun gear, ring gear, and balance gear is installed in the wheel. This segmentation allows the heavy motor to be excluded from unsprung mass while maintaining compact space through efficient gear train design.
2Weight of moving object
If the power source is installed separately from the wheel, then the unsprung mass is reduced improving ride comfort, but the space between power source and wheel increases
Solution Approach 1:
The balance gear rotates in a plane perpendicular to the rotation plane of the sun gear, creating a three-dimensional power transmission path. This spatial arrangement allows compact packaging of the gear train, reducing the overall space between the power source and wheel while maintaining separation of the motor from unsprung mass.
3Reliability
If a constant velocity joint is used to maintain continuous power transmission during vertical wheel movement, then power transmission continuity is improved, but the device complexity and space requirements increase
Solution Approach 1:
The connection between the sun gear and ring gear allows dynamic relative motion in the parallel plane through the balance gear mechanism. This dynamic connection naturally accommodates vertical wheel movement and maintains continuous power transmission without requiring constant velocity joints or other complex mechanical linkages.
4Device complexity
If the sun gear and ring gear are fixed in relative position, then the power transmission path is simplified, but the ability to accommodate vertical wheel movement is lost
Solution Approach 1:
The balance gear acts as an intermediary element between the sun gear and ring gear, enabling relative motion in the parallel plane while maintaining continuous engagement. This intermediary mechanism allows the system to adapt to vertical wheel movement without compromising the simplicity of the power transmission path.
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 enhances the durability and ride comfort of vehicles by decelerating input power speed and increasing torque, allowing continuous power transmission during vertical wheel movement without constant velocity joints, and optimizing space utilization between wheels.
Implementation Method 1
at least one gear train configured to allow relative motion between the rotation axes of the sun gear and the ring gear and to form a continuous power transmission state between the sun gear and the ring gear
Implementation Method 2
a ring gear provided such that a rotation axis thereof is moved relative to a rotation axis of the sun gear in a plane of rotation parallel to a plane of rotation of the sun gear, and at least one balance gear engaged with the ring gear
Data Source
AI summary
A universal driving device includes a sun gear rotatably provided, a ring gear, wherein a rotation axis of the ring gear is moved relative to a rotation axis of the sun gear in a plane of rotation parallel to a plane of rotation of the sun gear, at least one gear train configured to allow relative motion between the rotation axes of the sun gear and the ring gear and to form a continuous power transmission state between the sun gear and the ring gear, and at least one balance gear engaged with the ring gear.