Ball Screw Retainer Using Segmented Chains

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional ball screw devices face challenges in suitably fitting and engaging flexible coupling members or ball couplers into the endless ball guiding raceways between the screw shaft and the ball nut due to the attachment of ball circulating elements, leading to incomplete coupling of ball bearing elements.

Innovation Solution

A ball screw device design featuring a screw shaft with a helical groove, a movable ball nut with a helical groove, and a circulating device with a pathway that forms an endless ball guiding passage, along with a retaining device using spacers and flexible coupling chains to securely engage and position ball bearing elements, allowing easy assembly and complete engagement within the ball guiding passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ball circulating elements are attached to the ball nut to form the endless ball guiding passage, then the ball bearing elements can be guided through the helical groove portions, but the flexible coupling members cannot be suitably fitted and received into the ball guiding raceways

Engineering Contradiction:

Improveball bearing element guidanceVSAvoidflexible coupling member fitting

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The ball circulating elements are divided into multiple segments or blocks that can be separately positioned and assembled. This segmentation allows the coupling members to be fitted into the ball guiding raceways without interference from the circulating elements, as the segments can be arranged to create clear pathways for assembly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An intermediary structure or method is introduced between the ball circulating elements and the flexible coupling members. This intermediary mechanism facilitates the fitting process by temporarily holding or positioning the coupling members during assembly, allowing them to be properly received into the ball guiding raceways despite the presence of the circulating elements.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If flexible coupling members are used to couple ball bearing elements together, then complete engagement into ball guiding raceways is required, but the attachment of ball circulating elements prevents suitable fitting

Engineering Contradiction:

Improveball bearing element couplingVSAvoidassembly process

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The assembly process incorporates dynamic adjustment capabilities, allowing the flexible coupling members and ball circulating elements to be positioned and adjusted during assembly. This dynamic approach enables complete engagement into the ball guiding raceways while accommodating the presence of the circulating elements through flexible positioning and alignment adjustments.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8935967B2Roller element retainer for ball screw device

Publication Date: 2015.01.20 HIWIN TECH CORP

AI summary

A motion guide device includes a ball nut attached onto a shaft and having helical grooves for forming a ball guiding raceway between the ball nut and the elongated shaft and for receiving ball bearing elements, a circulating device attached to the ball nut and having a pathway communicative with the raceway for forming an endless ball guiding passage between the ball nut and the elongated shaft and the circulating device and for engaging with bearing elements, and a retaining device includes a shorter chain for engaging into the helical grooves or raceway of the screw shaft and the ball nut, and a longer chain for engaging into the pathway of the circulating device.