Vehicle Drive Layout With Sun Gear Support and Terminal Block Packaging
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Solution Overview
Problem
The existing vehicle drive devices face challenges in minimizing size due to the placement of terminal blocks, which can increase the overall dimensions when disposed above the electric motor or other components in limited engine compartment spaces.
Innovation Solution
The vehicle drive device incorporates a configuration where the input shaft, rotor shaft, and sun gear are arranged to transmit power without radial and thrust bearings, allowing the terminal block to be placed on the opposite side of the electric motor, reducing the device's size by eliminating the need for additional bearings and optimizing space usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal block is disposed above the electric motor or other components, then the electrical connection is achieved, but the size of the vehicle drive device increases
Solution Approach 1:
The terminal block is repositioned from a vertical arrangement (above the electric motor) to a horizontal arrangement on the opposite side of the electric motor from the planetary gear device. This dimensional change allows the terminal block to be accommodated within the existing lateral space of the engine compartment without increasing the axial height of the device.
2Reliability
If radial and thrust bearings are added to support the sun gear, then the reliability of power transmission is improved, but the axial dimension of the device increases
Solution Approach 1:
The sun gear is designed with integrated radial and thrust bearing functions combined into a single bearing structure. This merged bearing simultaneously supports both radial loads (from gear meshing) and axial thrust loads (from the sun gear), eliminating the need for separate radial and thrust bearings and thereby reducing the axial dimension while maintaining power transmission reliability.
Solution Approach 2:
The single bearing supporting the sun gear performs multiple functions: it acts as both a radial bearing to support the sun gear's radial position and a thrust bearing to support axial loads. This multi-functional bearing design reduces the total number of components and minimizes the axial space required compared to using separate specialized bearings for each function.
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 reduces the axial dimensions by eliminating radial and thrust load-bearing components, enabling the terminal block to be placed without increasing the device's size, thus maintaining compactness and improving component arrangement efficiency.
Implementation Method 1
a first ball bearing that supports the input shaft with respect to the case such that the input shaft is rotatable
Implementation Method 2
a thrust bearing disposed between one end surface of the sun gear in a direction of an axis and the input shaft
Implementation Method 3
a second ball bearing that is in contact with another end surface of the sun gear in the direction of the axis and that supports the rotor shaft with respect to the case such that the rotor shaft is rotatable
Data Source
AI summary
Power is transmitted between the input shaft and the rotor shaft by the sun gear and the gear meshing. This eliminates the need for bearings to receive radial loads. Further, a thrust bearing disposed between the one axial end surface of the sun gear and the input shaft, and a second ball bearing abutting the other axial end surface of the sun gear are provided. This eliminates the need for a bearing for receiving a thrust load of the sun gear. A terminal block is arranged in a space opposite to the planetary gear device with respect to the electric motor caused by the reduction of the bearing. Therefore, it is possible to dispose the terminal block while suppressing or avoiding the increase in the size of the vehicle drive device.