Electric Actuator Eccentric Gear Wear Reduction
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Solution Overview
Problem
Conventional electric actuators with speed reducers experience partial wear of the outer peripheral surface of the protruding portion due to constant contact with the inner peripheral surface, leading to failures in rotational force transmission and reduced efficiency.
Innovation Solution
The electric actuator design includes a motor shaft with an eccentric axis portion, a speed reduction mechanism featuring an externally toothed gear connected via a bearing, and column members that are rotatable around their central axis, allowing the externally toothed gear to swing and reducing wear by changing the contact position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protruding portion from the sun gear constantly contacts the hole portion of the output shaft for rotational force transmission, then reliable torque transmission is achieved, but partial wear occurs on the outer peripheral surface of the protruding portion
Solution Approach 1:
The invention makes the contact position dynamic by allowing the protruding portion to rotate around its own central axis while transmitting torque. This rotational movement of the protruding portion itself changes the contact point continuously, preventing concentrated wear at a single location and extending the service life of the components.
2Device complexity
If the contact position between sun gear and output shaft remains constant, then simple structure is maintained, but partial wear and failure occur
Solution Approach 1:
The invention introduces a simple rotational degree of freedom to the protruding portion, allowing it to rotate around its central axis. This dynamic element is easily integrated into the existing structure and effectively changes the contact position, preventing wear and maintaining transmission reliability without significantly complicating the overall device.
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 design minimizes wear on both the column members and the hole portions, preventing failures in torque transmission and maintaining precision in rotation angle, thus enhancing the efficiency and reliability of the speed reduction mechanism.
Implementation Method 1
The motor shaft has an eccentric axis portion centered on an eccentric axis that is eccentric with respect to the motor axis. The speed reduction mechanism has an externally toothed gear connected to the eccentric axis portion via the bearing
Implementation Method 2
an internally toothed gear that surrounds a radial outer side of the externally toothed gear and meshes with the externally toothed gear
Implementation Method 3
At least one of the plurality of column members is attached to the one member in a manner of being rotatable around a central axis of the at least one column member
Data Source
AI summary
An electric actuator includes a motor, a speed reduction mechanism, and a bearing fixed to a motor shaft having an eccentric axis portion. The speed reduction mechanism has: an externally toothed gear, an internally toothed gear, a facing member arranged facing the externally toothed gear, and column members arranged to protrude from one member of the facing member and the externally toothed gear toward the other member and surround the motor axis. The other member has hole portions arranged to surround the motor axis. The column members are inserted into the hole portions respectively, and support the externally toothed gear to be swingable around the motor axis via an inner side surface of each of the hole portions. At least one of the column members is attached to the one member in a manner of being rotatable around a central axis of the at least one column member.