Contact Safety Nut Mechanism for Linear Actuator Failure Takeover
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Solution Overview
Problem
Existing linear actuators face issues with safety nuts that cause violent impacts and position errors when the main nut mechanism fails, leading to potential damage and vibration, and they do not maintain stability and accuracy during normal operation.
Innovation Solution
A contact type safety nut mechanism with an elastic buffer element and safety ball that maintains a continuous elastic connection with the central screw, using limit hole channels filled with oil and thread teeth for enhanced stability and accuracy, ensuring the safety nut mechanism operates smoothly even when the driving nut fails.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the safety nut mechanism is kept separated from the central screw during normal operation, then normal operation of the screw lifter is not affected, but when the driving nut fails, violent impact occurs causing damage to the central screw and safety nut mechanism
Solution Approach 1:
The patent applies beforehand cushioning by pre-installing the safety nut mechanism in close proximity to the central screw, ready to engage immediately upon failure of the driving nut. The safety nut mechanism is positioned ahead of time so that when the driving nut fails, the safety nut can instantly take over without causing violent impact, thus cushioning the shock before it can cause damage to the central screw or safety nut mechanism.
2Reliability
If the safety nut mechanism is connected to the central screw to take effect immediately, then safety is improved, but the actuator produces obvious position error in the axial direction resulting in larger error of entire lifting control
Solution Approach 1:
The patent uses an intermediary approach by positioning the safety nut mechanism close to but not directly engaged with the central screw during normal operation. The safety nut acts as a standby component that can quickly engage when needed, serving as an intermediary safety mechanism that doesn't interfere with normal lifting control accuracy while providing immediate protection when failure occurs.
3Measurement precision
If the safety nut mechanism is kept separated from the central screw, then normal operation accuracy is maintained, but when failure occurs the actuator cannot immediately respond to prevent dangerous descent
Solution Approach 1:
The patent implements preliminary action by pre-positioning the safety nut mechanism in close proximity to the central screw, ready for immediate engagement. The safety nut is prepared in advance at the optimal position, so when the driving nut fails, it can instantly engage with the central screw to prevent dangerous descent, achieving both accuracy during normal operation and rapid response when failure occurs.
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 design ensures safety, stability, and maintains accuracy without position errors, allowing the linear actuator to complete tasks and descend to a safe height when the driving nut fails, reducing damage and vibration.
Implementation Method 1
an elastic buffer element (33) is arranged in each limit hole channel (32)
Implementation Method 2
the limit hole channels (32) are filled with oil
Data Source
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AI summary
The present disclosure relates to the technical field of aerial work platforms, in particular to a linear actuator with a contact type safety nut, and an aerial work platform. The linear actuator includes a central screw, a driving nut mechanism, and a safety nut mechanism. The central screw has a screw raceway. The safety nut mechanism includes a safety nut seat sleeved at the periphery of the central screw. Limit hole channels pointing to the central screw are arranged on the safety nut seat. An elastic buffer element is arranged in each of the limit hole channels. A safety ball is arranged between the elastic buffer element and the central screw. The contact type safety nut enables the linear actuator to always keep safety, stability, and no loss of accuracy in a conversion process that the safety nut mechanism gets involved to take effect while the driving nut mechanism fails.