Two-Stage Barrel Cam Speed Reducer for Compact Motor Layout
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Solution Overview
Problem
Conventional speed reducers that perform two-step speed reduction face challenges in achieving compactness due to the need to shift the motor attachment position, which compromises torque transmission capacity when positioned closer to the center, and protrusion issues when attached at the ends.
Innovation Solution
A speed reducer design that shifts the first barrel cam's center towards the intermediate shaft and adjusts its engagement position diagonally, allowing the motor to be positioned inwardly without reducing torque transmission capacity, thus enabling a compact form factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the motor attachment position is shifted to the upper end portion or lower end portion to increase torque transmission capacity, then the torque transmission capacity is improved, but the compactness of the speed reducer deteriorates
Solution Approach 1:
The patent shifts the barrel cam engagement position from the vertical dimension (upper/lower end portions) to the radial dimension (inner side toward the rotation axis). This dimensional change allows the motor to be positioned closer to the center, improving compactness while maintaining torque transmission capacity through the optimized radial engagement geometry of the barrel cam and cam followers.
2Volume of moving object
If the motor attachment position is set closer to the center to improve compactness, then the compactness is improved, but the torque transmission capacity decreases
Solution Approach 1:
The patent applies local quality optimization by specifically designing the barrel cam engagement surface and cam follower contact geometry at the radial engagement position. The engagement surface is configured with appropriate curvature and contact area to generate sufficient local contact force, ensuring that torque transmission capacity is maintained even though the motor is positioned closer to the center.
3Force
If the barrel cam engagement position is at the upper end or lower end to maximize torque transmission, then the torque transmission capacity is improved, but the motor protrusion increases
Solution Approach 1:
The patent resolves the motor protrusion issue by changing the engagement position from the vertical dimension (upper/lower ends) to the radial dimension (inner side). This allows the motor to be positioned closer to the center along the vertical axis, reducing motor protrusion while maintaining torque transmission capacity through the radial engagement configuration.
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 allows for a compact speed reducer with maintained torque transmission capacity by shifting the first barrel cam's center towards the intermediate shaft and adjusting its engagement position, reducing motor protrusion and enabling a more compact layout.
Implementation Method 1
a first barrel cam that is connected to the input shaft and that rotates as the input shaft rotates
Implementation Method 2
a second cam that is connected to the intermediate shaft, and that rotates as the intermediate shaft rotates
Data Source
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AI summary
a speed reducer including: an input shaft; a first barrel cam; a first output table; an intermediate shaft; a second cam; and a second output table, in the first output table, the plurality of first cam followers being provided concentrically around a rotation center position of the intermediate shaft, concerning a certain first cam follower among the plurality of first cam followers, when a center position of the certain first cam follower when the certain first cam follower has been moved to a farthest end on one side in the up-down direction is defined as a reference position, a center position of the first barrel cam being shifted to another side in the up-down direction with respect to the reference position, an engagement center position in the front-rear direction between an engagement start position and an engagement end position being shifted either of forward and rearward with respect to the reference position, the engagement start position being a position where the first barrel cam and the first cam followers start engaging, the engagement end position being a position where the first barrel cam and the first cam followers stop engaging.