Drive Transmission Coupling with Spherical End Face for Rotational Stability
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Solution Overview
Problem
Existing drive transmission devices in image forming apparatuses experience rotational irregularities due to fluctuations in force generated by compression springs, leading to misalignment and reduced rotational accuracy, which affects image quality and reliability.
Innovation Solution
A drive transmission device incorporating a coupling with a spherical end face and a truncated cone portion, where the coupling's couplers are axially movable into grooves of rotary bodies, and a spring presses the coupling toward the second rotary body, minimizing rotational irregularities by stabilizing the force fluctuation and enhancing torsional rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a compression spring is used to press the coupling, then the coupling is maintained in contact with the rotary bodies, but force fluctuations cause rotational irregularities and misalignment
Solution Approach 1:
The coupling incorporates a spherical end face that contacts a corresponding spherical surface on the second rotary body. This curved contact interface allows the coupling to self-align and compensate for misalignment caused by spring force fluctuations, thereby maintaining rotational accuracy while preserving the contact maintenance function of the spring.
Solution Approach 2:
The coupling design allows the couplers to be axially movable into and out of the grooves, creating a dynamic connection that can adapt to force variations. This dynamic capability enables the coupling to maintain reliable contact while accommodating the fluctuations in spring force without causing rotational irregularities.
2Device complexity
If the coupling structure is simplified, then the device complexity is reduced, but rotational accuracy and stability are compromised
Solution Approach 1:
The spherical end face and corresponding spherical contact surface provide self-aligning geometry that inherently compensates for misalignment. This geometric solution achieves high rotational accuracy without requiring complex adjustment mechanisms or precision mounting structures, thus resolving the contradiction between simplicity and precision.
Solution Approach 2:
The design changes the contact interface from a flat or point contact to a spherical surface contact, fundamentally altering the mechanical parameters of the coupling. This parameter change enables the coupling to accommodate misalignment and maintain rotational accuracy through its geometric properties rather than through complex structural features.
3Reliability
If the spring force is increased to ensure firm contact, then contact reliability is improved, but force fluctuation effects are amplified causing more severe rotational irregularities
Solution Approach 1:
The spherical contact interface acts as a mechanical compensator that converts the effects of force fluctuations into beneficial self-aligning moments. Even with increased spring force for firm contact, the spherical geometry ensures that any misalignment caused by force variations results in corrective alignment rather than rotational irregularities, thus decoupling contact firmness from rotational uniformity.
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 minimizes rotational irregularities and maintains image quality by stabilizing the force fluctuation and increasing torsional rigidity, ensuring reliable image formation without banding or uneven density.
Implementation Method 1
The spring presses the coupling toward the second rotary body from the first rotary body
Data Source
AI summary
A drive transmission device includes a first rotary body coupled to a drive source, a second rotary body that receives a drive force transmitted from the drive source, a coupling that couples the first rotary body and the second rotary body, and a spring that presses the coupling toward the second rotary body. Each of the first rotary body and the second rotary body includes a plurality of grooves. The coupling has axially opposed first end and second end coupled to the first rotary body and the second rotary body, respectively. The coupling includes a plurality of couplers on a circumferential surface of each of the first end and the second end. The plurality of couplers are axially movable into and out of the plurality of grooves of each of the first rotary body and the second rotary body. The coupling has a spherical end face at the second end.