Drive Coupling Spring Restrictors for Reliable Unit Engagement
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Solution Overview
Problem
Existing drive devices for image forming apparatuses face issues with the correct fitting of drive and driven couplings due to misalignment, leading to failure in rotational driving, which increases the size and cost of the apparatus when attempting to address this with additional components to hold compression springs.
Innovation Solution
A drive device incorporating a relay member and a compression spring with radial restrictors to maintain alignment and bias the drive coupling correctly, preventing misalignment and fitting failures without increasing the apparatus's size or cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a member that holds the compression spring is provided when the drive coupling is pressed to move in the axial direction by the driven coupling, then the fitting failure between drive coupling and driven coupling is prevented, but the cost and space increase, resulting in increased size and cost of the image forming apparatus
Solution Approach 1:
The patent merges the function of holding the compression spring into the drive coupling structure itself by providing an inner circumferential restrictor on the drive coupling that faces the inner circumference of the compression spring. This integrates the spring-holding function into the existing drive coupling component rather than adding a separate member, thereby preventing fitting failure without increasing device complexity or cost.
Solution Approach 2:
The drive coupling serves its own additional function of holding the compression spring through the inner circumferential restrictor. The drive coupling's own structure (with the restrictor) prevents radial movement of the compression spring, allowing the component to self-regulate its interaction with the spring without requiring external assistance from separate holding members.
2Reliability
If the drive coupling is pressed to move in the axial direction by the driven coupling without proper alignment, then the drive coupling does not move straightly, but providing a separate member to hold the spring increases cost and size
Solution Approach 1:
The patent combines the alignment-guiding function with the spring-holding function by providing an outer circumferential restrictor on the drive coupling that faces the outer circumference of the compression spring. This integrated restrictor structure ensures the drive coupling moves straightly in the axial direction while preventing radial movement of the spring, achieving proper alignment without adding separate heavy components.
Solution Approach 2:
The drive coupling's own structure (with the restrictors) ensures proper alignment and straight movement during axial motion. The restrictors guide the compression spring's position, allowing the drive coupling to self-align and move correctly without requiring additional alignment mechanisms or heavier support structures.
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 ensures proper fitting and alignment of drive and driven couplings, reducing axial reaction forces and maintaining efficient drive transmission, thus preventing operational failures and cost increments.
Implementation Method 1
a compression spring wound around the rotary shaft and having one axial end contacting the relay member and the other axial end contacting the contact member. The compression spring biases the drive coupling toward an axial end of the drive coupling in response to movement of the drive coupling toward another axial end of the drive coupling
Data Source
Figure 1~2
Figure 3~4B
Figure 5A~5B
AI summary
A drive device (30) that drives a detachable unit (20) detachably attached to an image forming apparatus (100) includes a drive coupling (36), a rotary shaft (35), a relay member (37), a contact member (34), and a compression spring (38). The drive coupling (36) contacts and separate from a driven coupling (26) of the detachable unit (20) along with movement of the detachable unit (20). The relay member (37) transmits rotation force of the rotary shaft (35) to the drive coupling (36). The compression spring (38) has an axial end contacting the contact member (34) and another axial end contacting the relay member (37). The drive coupling (36) includes an outer circumferential restrictor (36c) to restrict radial movement of the compression spring (38). The relay member (37) includes an inner circumferential restrictor (37e) to restrict radial movement of the compression spring (38).