Rotating Electric Machine Axial Length Reduction
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Solution Overview
Problem
The existing rotating electric machines used in power transmission devices have a length issue in the axial direction due to the placement of slip rings and power transmission units, which affects their installability and efficiency.
Innovation Solution
The design incorporates a first rotor with an inner space where a second rotor with coils is coaxially arranged, with the power transmission unit and bearings positioned to minimize axial length, including the placement of at least part of the power transmission unit within the second rotor's inner circumference and the bearings outside the power transmission unit radially, allowing for reduced overall length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power transmission unit is arranged outside the second rotor in the axial direction, then the electrical connection between coils and inverter is ensured, but the axial length of the rotating electric machine increases
Solution Approach 1:
The power transmission unit is nested inside the second rotor's inner circumference space, with the rotating member positioned within the inner circumference of the second rotor. This nesting arrangement allows the power transmission unit to be accommodated within the existing radial space rather than extending axially, thereby reducing the overall axial length while maintaining electrical connection functionality between the coils and inverter
Solution Approach 2:
The bearing arrangement is changed from axial alignment with the power transmission unit to radial positioning outside the power transmission unit. This dimensional reconfiguration allows the bearings to support the rotors while accommodating the power transmission unit within the inner circumference space, effectively transitioning the layout from axial stacking to radial arrangement, which reduces axial length
2Device complexity
If the bearings are arranged aligned with the power transmission unit in the axial direction, then the rotor support structure is simplified, but the axial length increases
Solution Approach 1:
The bearing arrangement is reconfigured from axial alignment to radial positioning. The bearings are positioned outside the power transmission unit in the radial direction rather than aligned axially with it. This dimensional change allows the power transmission unit to be accommodated within the inner circumference space of the second rotor, reducing axial length while the bearings continue to provide necessary rotor support through their radial positioning
3Length of moving object
If the axial length is reduced by repositioning components, then installability is improved, but the space for electrical connection and mechanical support becomes constrained
Solution Approach 1:
The power transmission unit is nested within the inner circumference space of the second rotor, utilizing the existing radial space efficiently. The rotating member of the power transmission unit is positioned within this inner circumference, allowing electrical connection components to be accommodated without extending the axial length. This nesting maintains component arrangement flexibility by using the available radial and circumferential space rather than requiring additional axial space
Solution Approach 2:
The component layout is reconfigured from axial arrangement to radial arrangement. The bearings are positioned radially outside the power transmission unit rather than aligned axially, creating space within the axial dimension for the power transmission unit to be nested inside the second rotor's inner circumference. This dimensional reconfiguration maintains adaptability by providing alternative spatial relationships for component placement
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 effectively reduces the axial length of the rotating electric machine, enhancing its installability and operational efficiency by minimizing the space required, particularly in vehicle-mounted applications.
Implementation Method 1
a second rotor being arranged at the inner side of the first rotor and having coils
Data Source
AI summary
Provided is a compound motor (14) comprising a magnet rotor (19) supported by bearings (B3, B4) in a rotatable manner, a winding rotor (20) supported by bearings (B5, B6) in a rotatable manner relative to the magnet rotor (19) at the inner side of the magnet rotor (19) and having rotor winding units (20b), and slip ring mechanisms (25). A space is formed in the inner circumference of the winding rotor (20). At least a part of the slip ring mechanisms (25) is arranged in the space of the inner circumference of the winding rotor (20). The bearings (B3 to B6) include bearings (B3, B6), the internal diameter of each is larger than the size of slip ring mechanisms (25) with respect to the radial direction. The bearings (B3, B6) are arranged outside the slip ring mechanisms (25) with respect to the radial direction.