Linear Electric Actuator with Nested Screw-Nut Transmission
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Solution Overview
Problem
Existing linear electric actuators for automotive applications lack precision, reliability, and adaptability, with increased demand for compactness and versatility while maintaining low costs, and current solutions fail to meet these requirements.
Innovation Solution
A linear electric actuator design featuring a DC electric motor with a control shaft supported by a main body, a screw-nut type coupling, dual bearings, and anti-rotation mechanisms, allowing for customizable stroke lengths and direction, with an integrated axial position sensor for precise control and robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional actuator designs are used, then basic functionality is achieved, but precision, reliability, and controllability of drive kinematics are insufficient
Solution Approach 1:
The actuator is divided into functionally independent modules: motor unit, transmission unit with screw-nut coupling, control shaft assembly with dual bearings, and sensor unit. This segmentation allows each module to be optimized for its specific function while maintaining overall reliability without excessive complexity.
Solution Approach 2:
An axial position sensor is integrated to provide feedback on the control shaft position, enabling precise control and monitoring of drive kinematics. This feedback mechanism ensures reliable operation while maintaining a relatively simple overall structure through intelligent control.
2Volume of moving object
If actuator dimensions are reduced to meet automotive space constraints, then compactness is achieved, but precision and reliability may be compromised
Solution Approach 1:
The control shaft is partially received within the main body housing, and the screw-nut coupling is nested within the transmission unit. This nesting arrangement achieves compact dimensions by efficiently utilizing internal space while maintaining precise mechanical relationships between components.
Solution Approach 2:
The motor shaft and control shaft are arranged in non-coaxial configurations (perpendicular or parallel but spaced apart), utilizing three-dimensional space efficiently. This dimensional arrangement allows compact packaging while maintaining precise drive kinematics through the transmission means.
3Adaptability or versatility
If standard actuator designs are used, then basic functionality is achieved, but adaptability to different driving strokes and directions is limited
Solution Approach 1:
The actuator design allows dynamic configuration of the control shaft length and stroke parameters. The transmission means can accommodate different screw-nut coupling configurations to achieve varying driving strokes and directions, providing adaptability without requiring fundamentally different actuator designs.
Solution Approach 2:
The actuator is designed as a universal platform that can be configured for multiple applications (butterfly valves, choke valves, EGR valves, gear shift selectors, aerodynamic appendages) through parameter customization rather than structural redesign, maintaining simplicity while achieving versatility.
4Ease of manufacture
If cost reduction is prioritized, then economic viability is improved, but precision, reliability, and controllability may deteriorate
Solution Approach 1:
The axial position sensor provides self-monitoring capability, enabling the system to detect and compensate for positioning variations automatically. This self-service approach maintains high measurement precision without requiring complex external measurement systems, thereby controlling costs.
Solution Approach 2:
The design replaces complex mechanical positioning systems with a combination of motor control and electronic position sensing. This substitution achieves high precision axial position control while reducing mechanical complexity and manufacturing costs compared to purely mechanical precision systems.
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 actuator achieves compact dimensions, high precision, and reliability with customizable stroke options, ensuring low cost and adaptability to specific user needs, while maintaining robustness and precise control.
Implementation Method 1
motor means (12), in particular a DC electric motor
Implementation Method 2
transmission means (16) transforming a rotation movement of the motor means (12) into a translation movement of the control shaft (20)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Actuator (4) for automotive applications, comprising: - a main body (8) housing motor means (12), transmission means (16), a control shaft (20), kinematically connected to said motor means (12) by means of said transmission means (16), - wherein the control shaft (20) extends from a first transmission end (24), connected to the transmission means (16), to a second operating end (28) operatively connected to a user device. The control shaft (20) is controlled in a reciprocating linear motion along an axial direction (Y-Y) by means of said transmission means (16) which transform a rotation movement along a drive axis (X-X) of the motor means (12) into a translation movement of the control shaft (20) along said axial direction (Y-Y); the motor means (12) and the control shaft (20) are oriented so that the drive axis (X-X) and the axial direction (Y-Y) are perpendicular or parallel and spaced apart from each other.