Friction Rotation Coupling for Low-Play Intersecting Shafts
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Solution Overview
Problem
Existing rotation transmitting devices in robots, which rely on bevel gears for torque transmission, face issues with play and accuracy due to dimensional tolerance, particularly in small motor and gear systems.
Innovation Solution
A rotation transmitting device using a first and second rotating shaft that intersect, with a transmitting member surrounding them, where rotation is transmitted through friction between the rotating parts and the transmitting member, allowing for precise alignment and reduced play.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bevel gears are used for rotation transmission from the motor's shaft to the driven shaft, then torque can be transmitted between intersecting shafts, but play occurs in the movement and alignment accuracy deteriorates due to dimensional tolerance
Solution Approach 1:
The patent replaces the traditional bevel gear mechanical engagement system with a friction-based transmission system. A friction member is pressed against the rotating shafts to transmit torque through friction force rather than gear meshing, eliminating the play and alignment issues inherent in gear systems while maintaining torque transmission capability between intersecting shafts
Solution Approach 2:
The patent changes the fundamental transmission parameter from mechanical engagement (gear teeth) to friction-based contact. By controlling the pressing force and friction coefficient between the friction member and rotating shafts, the system achieves accurate torque transmission without the dimensional tolerance problems that affect gear alignment
2Volume of moving object
If bevel gears are used in small actuators with built-in motors, then compact structure is achieved, but play and alignment difficulty increase due to small dimensional tolerances
Solution Approach 1:
In small actuators, the patent replaces miniaturized bevel gears with a friction transmission system using a friction member pressed against the motor shaft. This substitution eliminates the compounding effect of small dimensional tolerances that cause play in small gear systems, while maintaining the compact actuator structure necessary for robotic applications
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 solution effectively reduces play in rotation transmission and facilitates accurate alignment of the rotating parts, improving the precision and efficiency of torque transfer in robotic systems.
Implementation Method 1
The transmission of rotation from the rotating part of at least one of the first rotating part and the second rotating part to the transmitting member is accomplished by means of friction between an external surface of the at least one of the rotating part and an internal surface of the transmitting member
Data Source
AI summary
Disclosed herein is a rotation transmitting device which permits the transmission of rotation with a reduced play and which permits the constituents to be aligned easily. The rotation transmitting device has a transmitting member (30) which surrounds a rotating part (12) of a drive shaft (11) and a rotating part (22) of a driven shaft (21). At least either the rotating part (12) of the drive shaft (11) or the rotating part (22) of the driven shaft (21) has an external surface that comes into contact with the internal surface of the transmitting member (30) so that friction arising between the internal surface and the external surface achieves torque transmission and reception to and from the transmitting member (30).