Ball Screw Assembly with Recirculating Lubricant Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ball screw assemblies require frequent lubrication due to the presence of dead volumes that do not contribute effectively to lubrication, leading to inefficient lubrication and frequent servicing needs.
Innovation Solution
The implementation of alpha and beta lubricant channels and a shuttle mechanism within the ball screw assembly that promotes a recirculating lubricant flow path, minimizing dead volumes and enhancing lubrication efficiency by depositing lubricant further along the load circuits and into dedicated lubricant channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional lubrication channels are used in ball screw assemblies, then lubricant can be introduced into the closed channel or raceway, but dead volumes remain that do not contribute effectively to lubrication, requiring frequent servicing
Solution Approach 1:
The lubrication system is segmented into multiple independent channels (first lubricant channel and second lubricant channel) that distribute lubricant to different portions of the load circuit separately. This segmentation eliminates dead volumes by ensuring all areas are actively reached by dedicated lubricant pathways, improving lubrication effectiveness and extending service intervals.
Solution Approach 2:
The invention introduces lubricant channels that extend in the axial direction beyond the traditional radial or circumferential paths. The first lubricant channel extends beyond a first end of the closed channel in the axial direction, and the second lubricant channel extends beyond a second end, creating new lubrication zones in previously unreachable axial regions and eliminating dead volumes.
2Ease of operation
If lubricant is introduced through traditional oil or grease holes, then the closed channel or raceway can be lubricated, but dead volumes persist that reduce lubrication efficiency
Solution Approach 1:
The lubricant channels serve multiple functions: they introduce lubricant into the system, distribute it along the axial direction to multiple locations, and eliminate dead volumes simultaneously. This multi-functionality improves both the ease of operation (centralized lubricant introduction) and reliability (comprehensive coverage).
Solution Approach 2:
The lubricant channels are pre-configured to extend beyond the ends of the closed channel in the axial direction, ensuring that lubricant is delivered to all potential lubrication points before the ball bearings complete their circuit. This preliminary positioning of lubricant in extended channels ensures complete coverage without dead zones.
3Reliability
If the ball screw assembly is serviced frequently to maintain lubrication, then lubrication effectiveness is maintained, but operational downtime increases
Solution Approach 1:
The extended lubricant channels ensure continuous lubricant delivery throughout the entire axial length of the ball screw assembly, eliminating dead volumes where lubrication would be interrupted or insufficient. This continuous coverage maintains consistent lubrication throughout operation, extending service intervals and reducing downtime.
4Device complexity
If traditional single-channel lubrication is used, then the structure remains simple, but dead volumes are created that reduce lubrication efficiency
Solution Approach 1:
The lubrication system is divided into multiple segmented channels (first and second lubricant channels) that independently serve different regions. This segmentation improves lubrication efficiency by eliminating dead volumes while maintaining reasonable structural complexity through modular channel design.
Solution Approach 2:
The invention adds axial extension to the lubricant channels, creating a three-dimensional lubrication network that reaches beyond the traditional planar or radial boundaries. This dimensional expansion improves lubrication efficiency by accessing previously unreachable areas without proportionally increasing complexity.
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 design extends lubrication intervals and improves the service life of ball screw assemblies by ensuring consistent lubrication, reducing the frequency of servicing and maintaining operational efficiency.
Implementation Method 1
promotes a recirculating lubricant flow path, minimizing dead volumes and enhancing lubrication efficiency
Implementation Method 2
The relative rotational motion is converted to relative longitudinal motion or relative longitudinal motion is converted to relative rotational motion via a plurality of ball bearings that interact with both the screw shaft and the ball nut
Implementation Method 3
To lubricate the ball screw assembly, and to reduce friction and wear in the assembly, lubricant such as oil or grease is typically introduced into one or more of the closed channel or raceway and ball return channel through an oil or grease hole
Data Source
AI summary
A ball screw comprising a screw shaft, a ball nut, and alpha and beta load circuits. The alpha and beta load circuits each include first and second parts. The screw shaft is longitudinally extending with a longitudinal central axis (A) and at least part of the longitudinally extending surface of the screw shaft comprises an external thread, and at least one of the first parts of the alpha and beta load circuits comprise a part of the external thread. The ball nut comprises a body, a bore, the second parts of the alpha and beta load circuits, and an alpha and a beta lubricant channel. The bore is defined by the body, is longitudinally extending with a longitudinal central axis (A), has a first and second end, and has at least one longitudinally extending surface extending between the first and second ends.