Linear Drive Spindle Assembly With Welded Securing Disk
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing linear drive systems for automatic adjustment of furniture, particularly sick beds, are cost-intensive and time-consuming due to the need for milling longitudinal slots and using multiple bearings, which complicates the manufacturing process.
Innovation Solution
A securing disk made of weldable material is used to create a non-rotatable connection between the spindle and the worm gear, reducing the number of working steps and requiring only a single rear bearing, with options for orbital riveting and resistance butt welding for assembly, simplifying the structure and assembly process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple bearings and complex securing methods are used, then the reliability and stability of the linear drive are improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple functions into a single integrated bearing unit that simultaneously provides radial support, axial support, and non-rotatable securing. This merging eliminates the need for separate bearings and securing mechanisms, reducing device complexity while maintaining reliability through the unified design.
Solution Approach 2:
The bearing unit is designed to perform multiple functions: it supports radial loads, supports axial loads, and prevents rotation of the spindle. This multi-functional design replaces what would traditionally require multiple separate components, simplifying the overall structure while ensuring comprehensive mechanical support.
2Reliability
If traditional milling and pinning methods are used for securing the spindle, then the non-rotatable connection is achieved, but the manufacturing time and cost increase
Solution Approach 1:
The patent replaces complex mechanical securing operations (milling longitudinal slots and driving pins) with a simpler bearing unit installation process. The bearing unit inherently provides the non-rotatable connection through its integrated design, eliminating the need for time-consuming machining and assembly operations while maintaining connection reliability.
Solution Approach 2:
The invention extracts and eliminates the unnecessary intermediate steps of milling slots and driving pins from the manufacturing process. By integrating the securing function directly into the bearing unit, the patent removes these extraneous operations, streamlining production and reducing manufacturing time and cost.
3Ease of manufacture
If a single rear bearing with securing disk is used, then the ease of manufacture and assembly are improved, but the ability to transmit axial forces may be compromised
Solution Approach 1:
The bearing unit merges radial support, axial support, and rotational constraint functions into a single component. This integration ensures that axial forces are effectively transmitted through the bearing's internal structure while maintaining manufacturing simplicity, as the force transmission capability is built into the unified design rather than requiring additional components.
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
This solution simplifies the assembly, reduces manufacturing costs, and enhances the durability and stability of the linear drive by eliminating the need for complex bearing arrangements, allowing for efficient and rapid production while maintaining high torque transmission capabilities.
Implementation Method 1
a securing disk (26) arranged on the rear end of the spindle (18) comprising a weldable material so that the securing disk (26) bears flat against the rear end. The securing disk (26) is connected in material-bonded relationship at the contact surface to the spindle (18)
Implementation Method 2
it is possible to connect that projecting portion to the securing disk (26) in positively locking relationship by means of orbital riveting. In that case that rear projecting portion of the spindle expands over the inner edge of the central opening of the securing disk and thus spans across or projects over the inner edge of the central opening in the form of a mushroom, that is to say flattening radially outwardly
Data Source
AI summary
A linear drive comprising an electric motor driving a worm, a worm gear which meshes with the worm and which is connected non-rotatably to a spindle extending along a linear drive longitudinal axis or axis of rotation and which has a rear and a front end. The worm gear has a bearing seat for a rear bearing, with which the worm gear is mounted in a surrounding transmission housing. To simplify the manufacture of such a linear drive the invention proposes that the rear bearing is in the form of a fixed bearing, the spindle comprises a weldable material, a securing disk is arranged on the rear end of the spindle and the securing disk is connected to the spindle in bonded-material relationship.