Ball Screw Recirculation Member Mechanical Locking Connection

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Solution Overview

Problem

The existing two-part deflection bodies for ball screw drives require complex and costly ultrasonic welding for connection, which is time-consuming and prone to errors during assembly and transport.

Innovation Solution

The use of locking or clamping projections and receptacles on the body parts that snap or clamp into place, allowing for a purely mechanical connection that is easy to assemble and transport, eliminating the need for ultrasonic welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If ultrasonic welding is used to connect body parts, then connection strength is improved, but manufacturing complexity and time consumption increase

Engineering Contradiction:
Improveconnection strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent replaces the ultrasonic welding process (thermal/mechanical system) with a purely mechanical locking system using protrusions and recesses. The body parts are connected through geometric interlocking features that provide sufficient connection strength without requiring complex welding equipment or processes, thus reducing manufacturing complexity while maintaining connection integrity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The deflection body is divided into multiple body parts that are connected through standardized locking interfaces. This segmentation allows each part to be manufactured separately using simple injection molding, then assembled through the locking mechanism, avoiding the need for complex one-piece manufacturing or sophisticated joining processes.

Inventive Principle:
Principle #1Segmentation

2Reliability

If ultrasonic welding is used to connect body parts, then connection reliability is improved, but production time increases

Engineering Contradiction:
Improveconnection reliabilityVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The locking protrusions and recesses are pre-formed during the injection molding process of each body part. This preliminary action ensures that the connection features are already prepared and precisely positioned before assembly, allowing for rapid and reliable connection without requiring additional welding steps or post-processing, thereby reducing production time while maintaining connection reliability.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If locking projections are used for connection, then ease of assembly is improved, but connection strength may be reduced

Engineering Contradiction:
Improveease of assemblyVSAvoidconnection strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The locking system combines multiple functional features into a single integrated mechanism: geometric interlocking for strength, friction surfaces for grip, and positioning elements for alignment. This composite approach within the locking projection design achieves both ease of assembly and sufficient connection strength by utilizing multiple physical principles simultaneously rather than relying on a single mechanism.

Inventive Principle:
Principle #40Composite materials

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 provides a faster, cheaper, and more reliable connection between the body parts, ensuring a firm and leak-tight assembly that prevents lubricant escape, while simplifying the assembly process and reducing the risk of connection failure.

Implementation Method 1

locking or clamping projections which snap positively into locking or clamping receptacles provided on the other body part or clamp frictionally in the assembled end position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2221506B1Recirculation member for ball screw drive
Publication Date: 2012.05.09 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP2221506B1 patent drawingFigure 1~2
  • EP2221506B1 patent drawingFigure 3~4
  • EP2221506B1 patent drawingFigure 5~6

AI summary

The return element (1) has two parts (2, 3) connected with each other, where the parts limit a returning channel that guides a rolling body. A locking projection (7) or a clamping projection is provided at one of the parts and locks or jams with a locking recess (10) or a clamping recess provided at the other part at an assembled end position in a form-fit or frictionally engaged manner. The parts have centering elements (12, 13) that are formed as pin-like projections (14) and co-operate with centering guides (15) during assembling of the parts.