Rotary Drive Stiffness Control for Resonance Suppression
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Solution Overview
Problem
Conventional rotary drive devices face limitations in widening the control range of feedback control due to low resonance frequencies and high gains at resonance points, leading to restricted frequency settings for feedback control, which can result in vibration issues and color unevenness in image forming apparatuses.
Innovation Solution
A rotary drive device with a drive transmission portion comprising three or more members, where a high stiffness member is attached to a low-stiffness drive transmission member at the resonance point of the lowest resonance frequency, increasing the stiffness of the low-stiffness member and configuring other drive transmission points to transmit rotational force through the high stiffness member, thereby increasing the lowest resonance frequency and reducing the gain at the resonance point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If feedback control frequency is set close to the lowest resonance frequency to widen control range, then control range is widened, but resonance influence increases due to high gain at resonance point
Solution Approach 1:
The patent changes the stiffness parameter of the drive transmission members to modify the resonance frequency and gain characteristics. By adjusting the stiffness of specific transmission members, the system shifts the resonance frequency away from the feedback control frequency range, thereby reducing resonance influence while maintaining a wide control range.
Solution Approach 2:
The patent applies different stiffness characteristics to different parts of the drive transmission system. Specifically, certain drive transmission members are designed with higher stiffness while others maintain lower stiffness, creating localized stiffness variations that modify the overall resonance characteristics of the transmission path without requiring the entire system to be uniformly stiff.
2Speed
If stiffness of drive transmission member is increased to raise lowest resonance frequency, then resonance frequency increases, but device complexity increases
Solution Approach 1:
Instead of uniformly increasing the stiffness of all drive transmission members, the patent selectively increases the stiffness of specific members involved in the resonance phenomenon. This localized approach raises the resonance frequency while minimizing the addition of structural complexity, as only necessary components are modified.
Solution Approach 2:
The patent employs composite structures or materials in the drive transmission members to achieve higher stiffness without proportionally increasing complexity. By using composite designs, the system attains the required stiffness increase for raising resonance frequency while maintaining reasonable structural simplicity.
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 allows for a wider control range of feedback control, reducing rotational variation and improving image formation quality by increasing the lowest resonance frequency and lowering the gain at the resonance point, thus enhancing the stability and accuracy of rotation speed adjustment.
Implementation Method 1
a high stiffness member is attached to a low-stiffness drive transmission member... to increase stiffness of the low-stiffness drive transmission member
Implementation Method 2
a mesh between the drive gear and the driven gear
Implementation Method 3
a coupling between the driven gear and a parallel pin, and an insertion connection where the parallel pin is fitted in the driven shaft
Data Source
AI summary
A rotary drive device includes a drive motor and drive transmission portion, which transmits a rotational drive force of the motor to a driven rotor and includes three or more drive transmission members. A high stiffness member is attached to a low-stiffness drive transmission member, which is one, lower in stiffness, of two of the drive transmission members, to increase stiffness of the low-stiffness drive transmission member. The two form a drive transmission point corresponding to a resonant point of a lowest resonance frequency among frequencies at a plurality of resonance points in frequency response characteristics derived from rotation information. One drive transmission point, which is on either a drive-transmission input side or output side, other than the drive transmission point corresponding to the resonant point of the lowest resonance frequency, of the low-stiffness drive transmission member is configured to transmit the rotational drive force through the high stiffness member.