Linear Actuator Traveling Nuts Non-Axial Load Distribution
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Solution Overview
Problem
Existing linear actuators used in motion simulators face issues with non-axial loads leading to premature failure due to uneven distribution and leveraging effects, which affect their lifespan and performance.
Innovation Solution
A linear actuator design featuring a pair of traveling nuts with different thread pitches and rolled ball screw units, secured to a carriage with rotational degrees of freedom, which converts rotational motion into translation and distributes non-axial loads more evenly, reducing stress on components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single traveling nut is used in the linear actuator, then the structure is simple, but non-axial loads cause uneven distribution and leveraging effects leading to premature failure
Solution Approach 1:
The single traveling nut is segmented into a pair of traveling nuts positioned on opposite sides of the sliding tube. This segmentation allows the load to be distributed across multiple contact points with the threaded shaft, reducing the leveraging effect and preventing premature failure while maintaining reasonable structural complexity.
2Productivity
If the traveling nut is secured to form an integral unit with the sliding tube, then the conversion of rotational motion to translation is efficient, but non-axial loads create leveraging effects that impact component life
Solution Approach 1:
The integral unit is segmented into multiple traveling nuts distributed along the sliding tube. This allows the motion conversion function to be distributed across multiple engagement points with the threaded shaft, maintaining efficiency while reducing stress concentration and extending component life through load distribution.
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 enhances the lifespan and performance of linear actuators by evenly distributing non-axial loads and reducing angular tension, leading to improved reliability and longevity compared to traditional single-nut configurations.
Implementation Method 1
The traveling nuts each are rolled balls screw units, each said rolled ball screw units having balls operatively received in a helical raceway of the threaded shaft
Implementation Method 2
the traveling nuts being on opposite sides of a member of the sliding tube assembly connecting the traveling nuts to the sliding tube
Data Source
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AI summary
A linear actuator comprises a motor for producing a bi-directional rotational output. A casing is connected to the motor at a proximal end, the casing having an inner cavity defining a joint surface. A threaded shaft is within the inner cavity of the casing and actuated by the motor for rotation. A sliding tube assembly has a sliding tube in sliding arrangement with the inner cavity of the casing for moving in translation in an axial direction relative to the casing. A pair of traveling nuts is connected to the sliding tube assembly for moving with the sliding tube in the axial direction, the traveling nuts being operatively engaged to the threaded shaft for converting a rotational motion of the threaded shaft into a translation of the sliding tube, the traveling nuts being on opposite sides of a member of the sliding tube assembly connecting the traveling nuts to the sliding tube.