Motor Unit Radial Drive Integration for Axial Length Reduction
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Solution Overview
Problem
Existing motor units in hybrid and electric vehicles are limited by their axial size due to the parallel disposition of the drive unit with respect to the coil end, hindering miniaturization.
Innovation Solution
A motor unit design featuring a cylindrical stator and rotor with a drive unit that swells radially and is fixed to the case, incorporating a recess and refrigerant passage to allow for compact integration, enabling miniaturization while maintaining effective cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the drive unit is disposed parallel to the terminal of the coil end in the axial direction, then the motor unit can be assembled with simple structure, but the axial length of the motor increases
Solution Approach 1:
The drive unit is repositioned from an axial arrangement to a radial arrangement, changing the spatial dimension of integration. The drive unit is now disposed radially with respect to the coil end and integrated into the case structure, which reduces the axial length while maintaining assembly simplicity through the radial integration approach
2Length of moving object
If the drive unit is integrated into the case structure with radial disposition, then the axial length is reduced for miniaturization, but the structural complexity of the case increases
Solution Approach 1:
The drive unit is merged with the case structure by disposing the drive unit radially with respect to the coil end and fixing it to the case. The case is designed with a recess that corresponds to the swell of the drive unit, creating an integrated structure that reduces axial length while managing complexity through functional integration
3Volume of stationary object
If the recess is provided in the case for drive unit integration, then the drive unit can be compactly incorporated, but the refrigerant passage layout becomes more constrained
Solution Approach 1:
The case is designed with differentiated local structures: a recess is provided at the position corresponding to the drive unit swell to enable compact integration, while the refrigerant passage is routed through other portions of the case where space is available. This local differentiation allows both drive unit integration and refrigerant passage layout to coexist effectively
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 design allows for significant miniaturization of the motor unit by incorporating the drive unit within the case structure, while the refrigerant passages ensure efficient cooling, facilitating easier integration and reduced axial length.
Implementation Method 1
the case may further include a refrigerant passage that cools the stator from an inner circumferential surface of the case
Data Source
AI summary
Disclosed is a motor unit that includes: a rotary electrical machine that has a cylindrical stator, a rotor disposed coaxially with the stator, a shaft disposed coaxially with the rotor, and a cylindrical case that houses the stator and the rotor; and a drive unit that has a swell swelling toward the case and is fixed to a circumferential surface that is located in a radial direction of the rotor and is the case. The case has a recess that corresponds to the swell.