Spindle Drive Torque Limiter With Defined Slip Threshold
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing actuating drives for vehicle flaps are bulky and costly due to large torque-limiting devices and high material requirements, with unclear torque thresholds and significant friction-related production costs.
Innovation Solution
An actuating drive with a torque-limiting device featuring an adapter sleeve and rotationally fixed tolerance elements, where the tolerance elements are secured by retaining elements, allowing for a well-defined torque threshold and reduced material usage, eliminating the need for curing and minimizing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional torque-limiting device with large adapter sleeve is used, then the torque transmission is limited, but the structural volume and manufacturing cost increase significantly
Solution Approach 1:
The adapter sleeve is segmented into multiple tolerance elements (first tolerance element and second tolerance element) that can be arranged radially around the spindle rod. This segmentation reduces the volume of each individual element while maintaining the overall torque limitation function through distributed friction surfaces.
Solution Approach 2:
The tolerance elements are nested within the adapter sleeve structure, with multiple tolerance elements arranged concentrically around the spindle rod. This nested arrangement allows the torque-limiting function to be achieved with reduced overall volume compared to a single large adapter sleeve.
2Reliability
If a conventional torque-limiting device with large material outlay is used, then the torque transmission is limited, but the manufacturing cost increases
Solution Approach 1:
The adapter sleeve is segmented into multiple tolerance elements (first tolerance element and second tolerance element) that can be arranged radially around the spindle rod. This segmentation reduces the volume of each individual element while maintaining the overall torque limitation function through distributed friction surfaces.
Solution Approach 2:
The torque limitation is achieved by changing the friction parameters of the tolerance elements through surface treatment or material selection, rather than increasing the volume or mass of the adapter sleeve. This allows effective torque limitation with reduced material outlay.
3Device complexity
If a friction-based tolerance element connection is used, then the device is simple, but the torque threshold definition becomes unclear
Solution Approach 1:
The tolerance elements act as intermediaries between the adapter sleeve and the spindle rod, providing a controlled friction interface. By using multiple tolerance elements with specific friction characteristics, the torque threshold can be more precisely defined while maintaining relative simplicity in the connection mechanism.
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 provides a compact, cost-effective actuating drive with a defined torque threshold, reducing material usage and production costs while ensuring precise torque limitation, thus avoiding mechanical overloading and unintended flap adjustments.
Implementation Method 1
a first tolerance element arranged between the spindle rod and the first coupling element... limiting the torque transmitted from the first coupling element to the spindle rod
Data Source
AI summary
The invention relates to a control drive, in particular a spindle drive for adjusting a swivelable vehicle flap, comprising a housing (2), a spindle rod (3) that is rotatably mounted in the housing (2), a first coupling element (5) for driving a rotational movement of the spindle rod (3), and a torque-limiting device (6) arranged between the first coupling element (5) and the spindle rod (3) for limiting the torque transmitted from the first coupling element (5) to the spindle rod (3), comprising an adapter sleeve (8) arranged at a first end (3a) of the spindle rod (3) in a rotationally fixed manner, and a first tolerance element (13) arranged between the spindle rod (3) and the first coupling element (5). According to the invention, a control drive is provided, which is designed such that it is compact and can be economically produced, in such a way that the first tolerance element (13) is rotationally fixed to one of the first coupling element (5) and the adapter sleeve (8).