Built-In Parking Lock Gear Unit With Compact Axial Layout
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle driving units with integrated electric motors and reduction gear sets face challenges in compact design, leading to issues such as elongated lateral dimensions or elevated center of mass, which affect ride quality and stability.
Innovation Solution
A gear unit with a built-in parking lock device, incorporating a differential gear set, counter shaft, and parking gear, housed within a compact housing, utilizing a pawl and actuator mechanism to engage and disengage the parking gear, reducing size in both axial and lateral directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If elements are added alongside the electric motor having a laterally directed shaft, then the driving unit can accommodate all components, but the driving unit becomes elongated in the lateral direction and axles must be shortened, resulting in insufficient rocking capacity and adverse effect on ride quality
Solution Approach 1:
The patent repositions the parking lock device from a lateral arrangement to an axial arrangement along the output shaft. The pawl and parking gear are disposed axially on the output shaft, utilizing the axial dimension instead of lateral space, thereby avoiding lateral elongation while accommodating all necessary components
2Adaptability or versatility
If the driving unit dimensions are increased in the height direction, then all components can be accommodated, but the center of mass is set upward, damaging vehicle stability
Solution Approach 1:
The patent integrates the parking lock device directly into the existing gear unit structure by fixing the parking gear to the counter shaft and positioning the pawl within the same housing. This merging of functions into a compact integrated unit avoids increasing the overall height dimension and keeps the center of mass low
3Adaptability or versatility
If a parking lock device is added to the integrated driving unit, then parking function is provided, but the device complexity and number of elements increase
Solution Approach 1:
The counter shaft serves multiple functions: it transmits power through gears and simultaneously supports the parking gear. The housing serves both as a structural enclosure and as a mounting structure for the pawl. This multi-functionality reduces the need for separate dedicated components for each function
Data Source
AI summary
A gear unit to be used in combination with a power source having a hollow output shaft, is provided with: a differential gear set having a rotation axis in common with the output shaft; a counter shaft fixedly including a first gear in mesh with the output shaft and a second gear in mesh with the differential gear set, wherein the first gear and the second gear constitutes a reduction gear set; a housing including an outer wall parting the differential gear set and the counter shaft from an exterior and defining a single chamber; a parking gear fixed to the counter shaft and disposed axially opposite to the first gear beyond the second gear; and a parking lock device including a pawl pivoted on the outer wall.