Vehicle Drive Unit Layout With Shared Bearing Planetary Support
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Solution Overview
Problem
Existing drive units for vehicles require additional bearings to support the planetary gear mechanism, leading to increased size and complexity, and face challenges in efficiently utilizing space around the motor and differential mechanism due to interference from large-diameter components.
Innovation Solution
The drive unit integrates the parallel gear and carrier of the planetary gear mechanism, supported by two bearings, and optimizes the placement of the differential mechanism and inverter to reduce size by avoiding interference between large-diameter components, allowing for compact and rigid support and effective space utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the planetary gear mechanism is supported by additional bearings on both sides, then the support rigidity is improved, but the device complexity and size increase
Solution Approach 1:
The patent merges the support function for both the planetary gear mechanism and parallel gear into a single bearing structure. The bearing simultaneously supports the carrier of the planetary gear mechanism and the parallel gear, eliminating the need for separate bearings and reducing overall device complexity while maintaining support rigidity
Solution Approach 2:
The bearing is designed to perform multiple functions: it supports the planetary gear mechanism carrier and simultaneously supports the parallel gear. This multi-functional bearing reduces the total number of components needed while providing adequate support for both mechanisms
2Volume of moving object
If the parallel gear and planetary gear mechanism are positioned closer to the motor, then the space utilization is improved, but interference from large-diameter components increases
Solution Approach 1:
The patent positions the parallel gear and planetary gear mechanism in the radial direction rather than only in the axial direction of the motor shaft. By utilizing the radial space around the motor, the design achieves better space utilization while avoiding interference with large-diameter components along the axial direction
3Reliability
If three bearings are used to support the planetary gear mechanism, then the reliability is improved, but the manufacturing cost increases
Solution Approach 1:
The patent combines the support function for the planetary gear mechanism and parallel gear into a single bearing, reducing the total number of bearings from three to one or two. This reduction lowers manufacturing costs while the bearing is strategically positioned to maintain adequate support reliability for both mechanisms
Data Source
AI summary
A drive unit may be configured to drive a pair of left and right wheels of a vehicle. The drive unit may include: a motor; a planetary gear mechanism including a sun gear; a parallel gear coaxially fixed to a carrier; a first and bearing rotatably supporting the carrier and the parallel gear; and a differential mechanism meshing with the parallel gear and configured to distribute power from the parallel gear to the pair of left and right wheels. The sun gear may be connected to the motor and power may be input to the planetary gear mechanism from the motor. The power may be input to the parallel gear from the carrier. The first bearing may be disposed on one side relative to the carrier and the parallel gear and the second bearing may be disposed on other side of the carrier and the parallel gear.