Vehicle Transfer Drum Cam Mechanism for Compact Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle transfer systems require a large distance between the output shaft and fork shaft to accommodate the drum cam and clutch mechanisms, leading to increased size and interference issues.
Innovation Solution
A compact vehicle transfer system design that integrates a screw mechanism with an externally and internally threaded member, a drum cam, and a cam groove to reduce the distance between the output shaft and fork shaft, eliminating the need for a ball cam and lever, and improving switching response through inclined cam sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a drum cam and ball cam with lever are employed for controlling the transfer mechanisms, then the switching operation and torque adjustment can be achieved, but the distance between the output shaft and fork shaft must be relatively large, increasing the size of the transfer
Solution Approach 1:
The patent combines the drum cam for switching operation and the ball cam for torque adjustment into a single integrated cam structure. The drum cam has a first cam groove for controlling the switching mechanism and a second cam groove for controlling the torque, eliminating the need for separate cam mechanisms and reducing the overall size of the transfer.
Solution Approach 2:
The drum cam serves multiple functions simultaneously: it controls both the switching operation (through the first cam groove) and the torque adjustment (through the second cam groove). This multi-functionality reduces the number of components needed and allows for a more compact transfer design.
2Ease of operation
If the drum cam is mounted on the fork shaft parallel to the output shaft, then the switching operation can be controlled, but the lever requires a length larger than a predetermined value to ensure required torque, and interference with the high-low switching mechanism and clutch occurs
Solution Approach 1:
The patent merges the drum cam mounting location with the output shaft itself, rather than mounting it on a separate fork shaft. This integration eliminates the need for a parallel fork shaft arrangement and the associated lever mechanism, simplifying the overall device structure.
Solution Approach 2:
The patent uses an eccentric cam mechanism as an intermediary between the motor rotation and the linear motion required for switching operation. The eccentric cam converts rotational motion into linear motion directly, eliminating the need for a complex lever system and reducing interference with other components.
3Reliability
If the output shaft and fork shaft are positioned at a relatively large distance, then interference between the drum cam and clutch is avoided, but the size of the transfer increases
Solution Approach 1:
The patent merges the drum cam and clutch mechanisms into a more integrated arrangement where they share the same mounting location (the output shaft). This integration allows for closer positioning of components while maintaining proper functional separation through the cam groove design, reducing the overall size of the transfer.
Solution Approach 2:
The patent resolves spatial interference issues by utilizing different dimensional arrangements. The drum cam grooves are designed in specific patterns that allow the cam to control both switching and torque functions without interfering with the clutch, effectively using the cam groove geometry to manage spatial relationships between components.
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 achieves a more compact size and enhanced switching response by eliminating the need for a ball cam and lever, allowing for efficient power transmission and reduced electric power consumption while maintaining torque adjustment capabilities.
Implementation Method 1
a screw mechanism which is supported by the output shaft, and which includes an externally threaded member and an internally threaded member that are in thread engagement with each other, such that a rotatable threaded member that is one of the externally threaded member and the internally threaded member is rotatable by the electric motor, and such that the internally threaded member is moved along the common axis when the rotatable threaded member is rotated by the electric motor
Implementation Method 2
a drum cam which is connected to the rotatable threaded member, and which is rotatable about the common axis, the drum cam having a cam groove provided in an outer circumferential surface thereof; a second transmitting mechanism including a cam engaging member that is engaged in the cam groove of the drum cam, and configured to cause the fork shaft to be axially moved along the parallel axis through the cam engaging member when the drum cam is rotated about the common axis
Data Source
AI summary
A transfer includes: an input shaft; an output shaft; a high-low switching mechanism; an output member whose output destination is different from output destination of the output shaft; a clutch for transmitting a power to the output member; a first transmitting mechanism for transmitting movement of an internally threaded member to the clutch; and a drum cam having a cam groove. The cam groove includes a first inclined section that causes the high-low switching mechanism to be switched between a high-speed gear stage and a low-speed gear stage, and a second inclined section that causes the first transmitting mechanism to be switched between (i) a separated position in which the first transmitting mechanism is separated from the clutch and (ii) a contact position in which the first transmitting mechanism is in contact with the clutch, while the high-speed gear stage is established in the high-low switching mechanism.