Eccentric Gear Speed Changer for Bidirectional Shifting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gear speed change devices with one-way clutches enable smooth shifting in forward rotation but fail to function in reverse rotation, and are limited in compactness due to the number of parts required.
Innovation Solution
A gear speed change device with an input unit, internal/external gear, and rotation control unit, where the external gear and rotation control shaft are linked via an eccentric mechanism to allow smooth operation in both forward and reverse rotations, and a locking mechanism to stop the input shaft when the output shaft is locked.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a one-way clutch is used to prevent reverse rotation when the output means is locked, then the shifting function works well in forward rotation, but the shifting function cannot be exhibited when the input means rotates in reverse direction
Solution Approach 1:
The one-way clutch is removed from the system entirely. Instead of using a one-way clutch to control rotation direction, the patent uses a linking mechanism with an eccentric structure that naturally allows bidirectional rotation control through geometric constraints, enabling the shifting function to work in both forward and reverse rotations without a one-way clutch
Solution Approach 2:
Instead of using a one-way clutch that only allows rotation in one direction, the patent inverts the approach by using a symmetric linking mechanism that can control rotation in both directions equally, achieving bidirectional shifting capability through the eccentric geometry of the linking mechanism
2Reliability
If a one-way clutch is equipped in the speed change device, then reverse rotation can be prevented, but the number of parts increases and compactness is limited
Solution Approach 1:
The rotation control function is merged into the linking mechanism itself through the eccentric structure. The linking mechanism simultaneously performs the functions of connecting the input means to the output means and controlling the rotation direction, eliminating the need for a separate one-way clutch component while maintaining reliable rotation control
Solution Approach 2:
The linking mechanism is designed with multi-functionality, serving both as a connection element and as a rotation control element through its eccentric geometry. This universal component replaces the specialized one-way clutch, reducing the total number of parts while achieving the same rotation control reliability
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
Enables reliable and safe shifting in both forward and reverse rotations with a simple, compact structure, ensuring operation reliability and safety by stopping the input unit when the output shaft is locked.
Implementation Method 1
an eccentric guide portion 14 centered around an eccentric position deviated from an axis of the input shaft 11; an internal/external gear 20 with a fitting portion 17 rotatably held in the annular recess 15 on one side, and external teeth 18 and internal teeth 19 centered on the eccentric position on the other side
Data Source
AI summary
This gear speed change device is provided with an input unit 13 in which an eccentric guide portion 14 is formed centered about an eccentric position x1, on an input shaft 11 having an axial center x, an internal/external gear 20 which has external teeth 18 and internal teeth 19 having the center of rotation at the eccentric position x1, and one side of which is rotatably held by the eccentric guide portion 14, an output unit 24 which has an output shaft 12 on the axis x and on one side of which are formed internal teeth 22 that mesh with the external teeth 18 and that are centered about the axis x, and a rotation control unit 25 for controlling the rotational speed of the output unit 24.