Speed Reducer with Double-Ended Bearing for Rigidity
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Solution Overview
Problem
Existing speed reducers lack sufficient rigidity, leading to deformation and reduced performance in applications requiring high torque and compactness.
Innovation Solution
A speed reducer design featuring a gear with an annular power transmission portion surrounded by a bearing portion, and pinion gears with double-ended bearing structures to distribute reaction forces, enhancing rigidity and compactness while maintaining high torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional speed reducer design is used, then device complexity is reduced, but rigidity is insufficient leading to deformation
Solution Approach 1:
The speed reducer is divided into multiple movable portions (first movable portion, second movable portion, third movable portion) that can independently move in radial directions. Each movable portion holds specific gears and can be positioned independently, allowing the structure to adapt to load distribution requirements and improve rigidity without requiring a completely rigid complex structure.
Solution Approach 2:
The movable portions are configured to move in radial directions perpendicular to the rotational axes of the gears. This adds a radial dimension of adjustment capability to the traditional rotational movement, enabling the bearing portions to be positioned optimally to counteract reaction forces and improve overall structural rigidity.
2Volume of moving object
If compact design is implemented, then volume is reduced, but rigidity deteriorates causing deformation under high torque
Solution Approach 1:
The second movable portion is disposed inside the first power transmission portion, and the third movable portion surrounds the first gear from outside its inner periphery. This nested arrangement allows multiple bearing portions to be positioned in a compact configuration while maintaining their functional independence and ability to support reaction forces effectively.
Solution Approach 2:
The movable portions are designed to be movable in radial directions, providing dynamic adjustment capability. This allows the bearing portions to be repositioned based on operating conditions and load distribution, enabling the compact structure to maintain high rigidity under varying torque loads without requiring a fixed rigid framework.
3Strength
If bearing portions are added to improve rigidity, then structural strength increases, but device complexity increases
Solution Approach 1:
Each movable portion serves multiple functions: it holds gears for power transmission, provides bearing support, and enables radial movement for positioning. The second movable portion, for example, both transmits power through the second gear and provides bearing support at two locations (inside and outside the first power transmission portion), reducing the need for separate dedicated bearing components.
Solution Approach 2:
The bearing portions are integrated into the movable portions rather than being separate components. The first movable portion, second movable portion, and third movable portion each incorporate bearing functions while maintaining their primary gear-holding and power-transmission roles, thereby improving structural strength without proportionally increasing device complexity.
Data Source
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AI summary
To provide a speed reducer and an actuator effective for improving rigidity. A speed reducer 3 includes a gear 31, a pinion gear 32, a movable portion 34 holding the gear 31 so as to be rotatable around an axis Ax1, and a movable portion 35 holding the pinion gear 32 so as to be rotatable around an axis Ax2 non-parallel to the axis Ax1. The gear 31 has an annular power transmission portion 31a surrounding the axis Ax1 on one side in a direction along the axis Ax1. The pinion gear 32 has a power transmission portion 32a facing the power transmission portion 31a and transmitting rotational torque on an outer periphery. The movable portion 35 has a bearing portion 35a holding the pinion gear 32 inside the power transmission portion 31a and a bearing portion 35b holding the pinion gear 32 outside the power transmission portion 31a.