Concentric Transfer Mechanism for Compact Four-Wheel Drive
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing transfer systems for four-wheel drive vehicles are bulky due to the distanced rotation axes of the ring gear and input shaft, leading to increased size in the direction perpendicular to the rotation axis of the ring gear.
Innovation Solution
The transfer system is designed with a concentrically rotating input shaft within the ring gear, supported by bearings, and an intermesh disconnect mechanism actuated by an electromagnet and trip mechanism, allowing for a compact configuration by positioning the disconnect mechanism close to the ring gear and synchronizer between the movable meshing member and trip mechanism on the radially inner side of the ring gear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the ring gear and input shaft are positioned with distanced rotation axes, then the power transmission path is simplified, but the size of the transfer increases in the direction perpendicular to the rotation axis of the ring gear
Solution Approach 1:
The input shaft is nested inside the ring gear, with the input shaft's rotation axis coinciding with the ring gear's rotation axis. This concentric arrangement allows the input shaft to be positioned within the hollow space of the ring gear, significantly reducing the transfer's size in the direction perpendicular to the rotation axis while maintaining a simplified power transmission path.
2Ease of operation
If the disconnect mechanism is positioned far from the ring gear, then the mechanism has sufficient space to operate, but the overall transfer size increases
Solution Approach 1:
The disconnect mechanism is arranged in the axial direction (parallel to the rotation axis) rather than in the radial direction (perpendicular to the rotation axis). By positioning the disconnect mechanism between the bearings along the axial dimension, the patent provides sufficient operation space for the disconnect mechanism while minimizing the transfer's size in the perpendicular direction, achieving compactness without compromising operational capability.
3Adaptability or versatility
If multiple components (ring gear, input shaft, disconnect mechanism) are provided in the transfer, then the four-wheel drive function is achieved, but the size of the transfer increases
Solution Approach 1:
The input shaft and ring gear are merged into a concentric configuration where the input shaft is positioned inside the ring gear with coinciding rotation axes. This merging of spatial arrangements allows both components to occupy overlapping space, reducing the overall footprint of the transfer while maintaining the necessary four-wheel drive functionality through the disconnect mechanism.
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 size of the transfer in both the direction perpendicular and parallel to the rotation axis of the ring gear, enhancing compactness and reducing electric power consumption while maintaining effective power transmission.
Implementation Method 1
The actuator includes a trip mechanism and an electromagnet
Implementation Method 2
both ends of the input shaft may be supported by a pair of bearings provided inside a case such that the input shaft rotates concentrically with the ring gear
Data Source
AI summary
A transfer for a four-wheel drive vehicle, the vehicle including a driving source, main/auxiliary drive wheels, and a power transmission member, the transfer includes: a ring gear being supported so as to rotate around a rotation axis, and configured to drive the power transmission member; an input shaft extending through an inside of the ring gear, being supported so as to rotate concentrically with the ring gear, and being configured to receive part of the driving force; a disconnect mechanism; and an actuator configured to change the disconnect mechanism between a connection position and a disconnection position, the connection position being a position at which the ring gear and the input shaft are coupled to each other so as not to relatively rotate, the disconnection position being a position at which relative rotation between the ring gear and the input shaft is allowed.