Coaxial Electric Power Steering Layout for Compact Vehicle Integration
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Solution Overview
Problem
Conventional electric power steering apparatuses for vehicles have a layout issue due to the exposure of the electric motor, which causes interference with other structures, leading to a non-compact design.
Innovation Solution
The electric power steering apparatus features a coaxial disposition of the motor shaft, input shaft, and pinion shaft, with the electric motor supported on the inner surface of a housing and a planetary gear assembly that includes first and second planetary gears, a carrier, and a connection shaft, allowing the pinion shaft to extend through the motor shaft and connect with the input shaft, thereby preventing motor exposure and enhancing compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the electric motor is mounted exposed in the conventional electric power steering apparatus, then the motor can be easily accessed and maintained, but it causes interference with other vehicle structures and results in a non-compact layout
Solution Approach 1:
The electric motor is nested within the housing structure, with the motor shaft extending through the housing. This nesting arrangement allows the motor to be contained within the existing structural envelope, eliminating the need for external mounting while maintaining accessibility through the extended motor shaft.
Solution Approach 2:
The motor shaft extends through the housing in a dimensional configuration that allows the motor to be positioned within the housing volume while maintaining external accessibility. This dimensional arrangement resolves the conflict between internal containment and external accessibility.
2Ease of manufacture
If the electric motor is exposed in the conventional design, then the structure is simpler to manufacture, but it creates interference with other vehicle structures
Solution Approach 1:
The motor mounting structure is merged with the housing structure, where the housing serves dual purposes as both a structural component and a motor mounting enclosure. This integration eliminates the need for separate motor mounts and reduces the number of external connections required.
Solution Approach 2:
The electric motor is nested within the housing, allowing the motor to be contained within the existing structural envelope. This nesting arrangement eliminates interference with other vehicle structures while maintaining a integrated design that does not significantly complicate manufacturing.
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 configuration prevents interference with other vehicle structures, resulting in a more compact and efficient electric power steering apparatus layout that effectively transfers steering forces while minimizing space usage.
Implementation Method 1
a planetary gear assembly which includes a plurality of first planetary gears externally engaged with the sun gear and internally engaged with a first ring gear fitted in the housing, a plurality of second planetary gears connected to the plurality of first planetary gears by connection shafts respectively and internally engaged with a second ring gear
Implementation Method 2
the other end thereof which is connected to the input shaft by means of the torsion bar
Data Source
AI summary
Disclosed is an electric power steering apparatus for a vehicle. The electric power steering apparatus for a vehicle has a structure in which a motor shaft, an input shaft, a pinion shaft, and the like are coaxially disposed to improve a structure of a conventional art in which an electric motor is essentially exposed, so as to prevent interference with other structures, thereby forming a layout of the steering apparatus to be compact.