Twisted Spline Toothing for Deflection Angle Torque Transmission

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Solution Overview

Problem

Existing drive spindle systems in rolling mills face challenges in transmitting increased torque due to the small diameter of work rolls, leading to energy losses and edge wear, which limits the deflection angle and torque transmission capabilities.

Innovation Solution

A spline design with a modified toothing that allows for a deflection angle between the toothing and a complementary toothing, featuring parabolic reductions in tooth roots and tips, and a curved generatrix, which optimizes torque transmission by reducing edge wear and distributing load evenly over the tooth height.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the diameter of work rolls is increased to transmit higher torque, then torque transmission capability is improved, but energy losses increase and the roll stand must be designed stronger

Engineering Contradiction:
Improvetorque transmission capabilityVSAvoidenergy losses
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent applies a twisted toothing design where the tooth flanks are curved along the generatrix, creating a three-dimensional twisted surface. This curvature allows the contact line to be distributed along the tooth height, enabling higher torque transmission without increasing work roll diameter, thus avoiding the energy losses associated with larger rolls

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Adaptability or versatility

If cardanic joints are used between drive spindle and roller, then angular misalignment is accommodated, but torque transmission capability is insufficient

Engineering Contradiction:
Improveangular misalignment accommodationVSAvoidtorque transmission capability
Core Design Contradiction:
Adaptability or versatilityVSPower

Solution Approach 1:

The twisted toothing with curved tooth flanks and distributed contact line provides both angular adaptability and high torque transmission capability in a single integrated design, eliminating the need for cardanic joints that limit torque transmission

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Adaptability or versatility

If classic toothing is used at a deflection angle, then deflection angle is achieved, but edge wear occurs which limits torque transmission

Engineering Contradiction:
Improvedeflection angle capabilityVSAvoidedge wear
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The twisted toothing design with curved tooth flanks distributes the contact line along the tooth height, preventing concentration of stresses at the edges. This curvature geometry eliminates edge wear even at deflection angles up to 45 degrees, significantly improving reliability

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent transitions from traditional two-dimensional tooth profiles to a three-dimensional twisted toothing where the contact line is distributed along the tooth height. This dimensional change from point/line contact to distributed line contact along the generatrix prevents edge wear and enables high torque transmission at deflection angles

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP2723513B1Toothing for operation at a deflection angle and production method
Publication Date: 2016.04.27 SMS GROUP GMBH
  • EP2723513B1 patent drawingFigure 1~2
  • EP2723513B1 patent drawingFigure 3~4
  • EP2723513B1 patent drawingFigure 5

AI summary

The invention relates to a toothing (1), in particular of a drive spindle for driving a roll (13) in rolling mills or continuous casting plants, which comprises several teeth (2) and meshes with a second toothing in the manner of a spline, wherein a flank line (12) of the teeth (2) has a curvature and a deflection angle is formed between the rotational axis of the second toothing and the rotational axis of the toothing, wherein the toothing (1) is designed as having at least one of the following modifications: a tooth root relief of the teeth (2), and/or a tooth tip relief of the teeth (2), and/or a twist of the teeth (2).