Inverted Roller Screw Reducer Direct Coaxial Coupling

Solution Overview

Problem

Existing roller reducers with stepped threaded rollers cannot transmit full rotation to a working body without an intermediate gear due to space constraints, as mechanical locking elements interfere with the coaxial coupling, limiting their application in scenarios where space for gears is unavailable.

Innovation Solution

A roller reducer design featuring input, support, and output member nuts with multi-start threads of different directions, where rollers engage with these nuts externally, allowing direct external loading without an intermediate gear, enabling full rotation transmission by arranging the output member internally within the input member.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical locking elements are arranged outside the nuts to prevent rotation and displacement, then the nuts are securely fixed, but the mechanical elements interfere with the coaxial coupling between the output member and the working body shaft

Engineering Contradiction:

Improvefixing of nutsVSAvoidcoaxial coupling

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The locking elements are nested inside the output member nuts rather than being arranged outside. The nuts have a hollow internal structure that accommodates the locking elements, allowing them to be securely fixed without interfering with the coaxial coupling to the working body shaft.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The locking mechanism transitions from a radial arrangement (outside the nuts) to an axial arrangement (inside the nuts). This dimensional change allows the locking elements to be positioned along the axial direction within the nut's internal space, eliminating interference with the coaxial coupling.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If an intermediate gear is used to transmit rotation from the reducer output member to the working body, then full rotation can be transmitted, but the device complexity increases and space requirements increase

Engineering Contradiction:

Improverotation transmissionVSAvoidstructure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The intermediate gear is extracted from the system by implementing direct coaxial coupling between the output member and the working body shaft. The output member is designed with an internal hollow structure that directly receives the shaft, eliminating the need for intermediate transmission elements.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The output member and the working body shaft are merged into a single integrated assembly through direct coaxial coupling. The hollow internal structure of the output member directly accommodates the shaft, combining what were previously separate components (reducer output and working body) into one unified structure.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If an intermediate gear is used to transmit rotation, then full rotation can be transmitted, but the area occupied by gears and elements increases

Engineering Contradiction:

Improverotation transmissionVSAvoidspace for gears

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The intermediate gear is extracted from the system by implementing direct coaxial coupling between the output member and the working body shaft. The output member is designed with an internal hollow structure that directly receives the shaft, eliminating the need for intermediate transmission elements.

Inventive Principle:

Principle #2Taking out (Extraction)

4Volume of moving object

If rollers are arranged within the input member nuts and outer member nuts, then the structure is compact, but the space within the nuts is occupied by rollers, preventing proper mechanical locking

Engineering Contradiction:

Improvereducer dimensionsVSAvoidlocking of nuts

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The locking elements are nested inside the output member nuts rather than being arranged outside. The nuts have a hollow internal structure that accommodates the locking elements, allowing them to be securely fixed without interfering with the coaxial coupling to the working body shaft.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 allows for the transmission of full rotation from the reducer output member to a reciprocal mechanism without an intermediate gear, enhancing the versatility and space efficiency of roller reducers by enabling direct mounting on equipment, thus overcoming the limitations of prior art.

Implementation Method 1

Roller reducers can be used in robots, manipulators and power drives requiring transmission of large torques

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

roller reducers having stepped threaded rollers... providing high kinematic accuracy provided by a short kinematic chain and many contact points

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentUS10871202B2Inverted roller screw reduction gear

Publication Date: 2020.12.22 JOINT STOCK COMPANY DIAKONT

AI summary

A roller reducer comprises: an input member, a support member, an output member, and rollers, wherein the output member comprises output member nuts having a number of thread starts different from the number of thread starts on the support member nuts, wherein the rollers are arranged around the at least two support member nuts and the at least two output member nuts in such manner that each roller portion out of at least one pair of roller portions engages at least one of at least one of the support member nuts and at least one of the output member nuts.