Motor Generator Pulley Retention Under Nut Loosening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing motor generators suffer from a minute gap between the key groove and key, allowing the pulley to pivot and loosen, potentially causing the pulley to fall out of the rotation axle when the nut loosens.
Innovation Solution
A pulley falling prevention member is mounted on the rotation axle, featuring a base portion extending radially and an axial-direction extending portion that abuts the pulley to prevent it from falling, with gaps designed to minimize frictional forces and ensure stable attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a key groove and key are provided to prevent rotation torque from loosening the nut, then the pulley can be secured against rotation torque, but a minute gap between the key groove and key allows the pulley to pivot and gradually loosen the nut
Solution Approach 1:
The solution divides the protection function into two separate components: the key groove and key handle rotation torque prevention, while the pulley falling prevention member handles nut loosening and pulley detachment prevention. This segmentation allows each component to specialize in one function without compromising the other.
Solution Approach 2:
The pulley falling prevention member acts as an intermediary component between the pulley and the rotation axle. It provides an additional safety mechanism that mediates the connection, preventing direct pulley detachment even when the nut loosens, thus bridging the gap between the fastening system and the pulley.
2Strength
If the nut is used to fasten the pulley to the rotation axle, then the pulley can be securely attached, but when the nut loosens the pulley may fall out of the rotation axle
Solution Approach 1:
The pulley falling prevention member is installed in advance as a protective measure against nut loosening. It provides a safety buffer that prevents catastrophic pulley detachment even if the nut fails, cushioning against the potential harm of complete attachment failure.
Solution Approach 2:
The pulley falling prevention member is strategically positioned at a specific location on the rotation axle where it can effectively intercept a loosening nut. The component has localized engagement features that provide precise mechanical interference to prevent pulley fall-out.
3Ease of manufacture
If gaps are provided between the pulley falling prevention member and other components, then frictional forces are reduced and assembly is easier, but the structure becomes more complex
Solution Approach 1:
The gaps between the pulley falling prevention member and adjacent components enable dynamic adjustment and thermal expansion compensation. This dynamic design allows the system to adapt to operational conditions while maintaining ease of assembly and disassembly.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
There is provided a motor generator that makes it possible that even when a nut for fastening a pulley to a rotation axle loosens, the pulley is prevented from falling out of the rotation axle. In a motor generator (1), while being fit to the outer circumferential surface of the one end of a rotation axle (11), a pulley (12) is fastened to the rotation axle (11) with a nut (14) screwed to a male screw portion (11b) provided in the outer circumferential surface of the rotation axle (11) at the axial-direction one side (X1) of the fitting portion of the pulley (12), and on a portion of the rotation axle (11) at the axial-direction one side (X1) of the nut (14), there is mounted a pulley falling prevention member (9) that prevents the pulley (12) from falling out of the rotation axle (11) when the nut (14) loosens.