Harmonic Pin-Ring Transmission With Constant Pin Engagement
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Solution Overview
Problem
Current harmonic pin ring transmission systems face inefficiencies due to the lack of a robust mechanism for transmitting torque without bending moments, leading to uneven load distribution and potential wear on components.
Innovation Solution
The implementation of a harmonic pin ring drive with a deformable thin-ring ball bearing and pin retaining ring, utilizing an oval or sinusoidal circular shape for the rotor flange, which distributes force evenly across pins and teeth, ensuring constant engagement and low surface pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional harmonic drive mechanism is used, then torque transmission is achieved, but bending moments cause uneven load distribution and component wear
Solution Approach 1:
The patent employs an oval-shaped rotor flange with sinusoidal curvature that generates a wave motion pattern, causing pins to move in a curved trajectory that maintains constant engagement with gear teeth. This curved motion path eliminates bending moments by ensuring forces are always applied radially, resulting in uniform load distribution across all pins and teeth throughout the rotation cycle.
2Power
If pins are engaged with teeth throughout rotation, then power density is improved, but mechanical stress on pins increases
Solution Approach 1:
The sinusoidal wave motion generated by the oval rotor flange creates a curved pin trajectory that maintains constant radial engagement between pins and teeth. This curved path distributes mechanical stress uniformly across all pins throughout the rotation cycle, preventing stress concentration on individual pins while maintaining continuous power transmission, thereby achieving high power density without excessive mechanical stress.
3Volume of moving object
If a compact harmonic drive design is implemented, then space efficiency is improved, but surface pressure on contact points increases
Solution Approach 1:
The patent achieves continuous engagement of all pins with gear teeth throughout the entire rotation cycle through the wave motion mechanism. This continuous action distributes the load across all contact points simultaneously, reducing surface pressure at any single point while maintaining compact dimensions. The constant engagement ensures that the compact design does not concentrate forces on limited contact areas.
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 configuration achieves high efficiency, low wear, and a compact design by ensuring all pins remain engaged with teeth, resulting in improved power density and reduced mechanical stress.
Implementation Method 1
A deformable thin-ring ball bearing (102) with a deformable inner ring (123) and a deformable outer ring (124) is shrunk onto the oval cam (104)
Data Source
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AI summary
A harmonic pin-ring gear drive comprises an input shaft, an output shaft, two external gears each with internal teeth, and a single internal gear with external teeth. The internal gear is concentric to a first external gear and axially located inside the first external gear. A drive element extends between the two external gears and the internal gear and includes a circumferentially continuous pin retainer ring and a plurality of pins that project laterally from the pin retainer ring in the axial direction. A rotating transmitter lifts the drive element from the external teeth of the internal gear and presses the drive element into the internal teeth of the external gears.