Ball Screw Deflection Device Sleeve Compression

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Solution Overview

Problem

Existing ball screw designs face challenges in achieving high wear resistance while maintaining low production costs, particularly in the deflection device where rolling elements need to be efficiently guided and returned without requiring complex latching devices.

Innovation Solution

A ball screw design featuring a deflection channel formed by a radially inner first body part and a radially outer second body part, with tubular ends connected via a transfer area, where the first body part provides a radially inner boundary and the second body part provides a radially outer and lateral boundary, allowing for precise alignment and operation without latching devices, and a sleeve encloses the nut to press the deflection device into place, ensuring optimal positioning and reduced wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If latching devices are used to secure the deflection device components, then reliability of component positioning is improved, but device complexity and production costs increase

Engineering Contradiction:
Improvepositioning reliabilityVSAvoiddeflection device complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The deflection device components self-align and secure to each other through their geometric shapes and相互配合 surfaces, eliminating the need for external latching devices. The first and second body parts automatically maintain their relative positions through the deflection channel geometry and rolling element paths.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The latching devices are completely removed from the deflection device design. The patent achieves reliable positioning without these additional components by using the inherent geometry of the deflection channel and the pressure from the sleeve to maintain component alignment.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of manufacture

If a two-part deflection device is used to form the deflection channel, then ease of assembly and maintenance is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveassembly easeVSAvoidalignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The two body parts automatically align themselves through their相互配合 surfaces and the geometry of the deflection channel. The rolling elements and the channel shape guide the components into their correct relative positions, eliminating the need for complex external alignment procedures.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The deflection channel geometry itself acts as an intermediary that guides and aligns the two body parts. The channel shape and the rolling element paths serve as natural alignment features that ensure precise positioning without requiring additional alignment mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If the deflection device projects radially beyond the nut, then ease of assembly is improved, but wear resistance decreases due to exposure to external factors

Engineering Contradiction:
Improveassembly easeVSAvoidwear exposure
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The protective function is extracted and assigned to a separate sleeve component that encloses the nut and deflection device. This sleeve shields the previously exposed deflection device components from external harmful factors while maintaining the ease of assembly provided by the projecting design.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sleeve provides beforehand protection by enclosing the deflection device components before they are subjected to operational wear. This protective enclosure prevents direct exposure to harmful external factors while allowing the deflection device to maintain its functional projecting configuration.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 enhances wear resistance and reduces production costs by eliminating the need for latching devices, ensuring precise rolling element paths and reduced wear, while allowing for simpler assembly and maintenance, and operates effectively across a wide temperature range.

Implementation Method 1

in the presence of the sleeve, this exerts a radially inwardly directed force on the deflection device

Methodology Applied
Scientific EffectRadial force: Mechanical Force

Implementation Method 2

the balls, or in general, the rolling elements of the screw drive constantly roll in the thread when it is actuated

Methodology Applied
Scientific EffectRolling: Roller

Implementation Method 3

The ball screw works with low friction, low wear

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2997286B1Ball screw
Publication Date: 2019.11.20 SFS INTEC HLDG AG
  • EP2997286B1 patent drawingFigure 1
  • EP2997286B1 patent drawingFigure 2
  • EP2997286B1 patent drawingFigure 3~5

AI summary

The invention relates to a ball screw (10) with a threaded spindle (12), a nut (14), rolling bodies (16) and at least one deflecting device (18, 20), wherein the threaded spindle (12) is displaceable by rotation, and wherein the deflecting device comprises an inner first body part (18) and an outer second body part (20), which body parts together form a deflecting channel (22), wherein the deflecting channel (22) has two tubular ends (24, 26) which are connected to each other via a transfer region (28), wherein the tubular ends (24, 26) of the deflecting channel are in each case formed by mutually complementary partial tubular sections (30, 32, 34, 36) of the body parts (18, 20), and wherein a sleeve (40) surrounding the nut (14) is provided, the deflecting device (18, 20) sits in an opening (42) in the nut (14), the deflecting device (18, 20) projects radially beyond the outer lateral surface of the nut (14) in a relaxed state when the sleeve (40) is absent and, in the presence of the sleeve (40), said sleeve exerts a radially inwardly directed force on the deflecting device (18, 20).