Non-Circular Gear Drive for Combing Machine Draw-Off Rolls

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Solution Overview

Problem

Existing drive systems for detaching rollers in combing machines face limitations in reducing torque loads and enhancing the design freedom of the movement curve, leading to increased power requirements and limited adjustability.

Innovation Solution

The use of a gear stage with non-circular gears for the sun gear of the differential gear converts uniform rotary motion into an irregular motion, combined with a drive shaft and gear wheel configuration that synchronizes drive paths and allows for adjustable fastening to optimize the movement curve of the detaching rollers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a differential gear with lever mechanism and eccentric drive is used, then the pilgrim-step movement is generated, but the device complexity increases and frictional forces increase power requirements

Engineering Contradiction:
Improvemovement generationVSAvoidgear design complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex lever mechanism and eccentric drive from the differential gear system. Instead of using these additional components, the invention directly drives the carrier of the differential gear, simplifying the overall structure while maintaining the pilgrim-step movement generation capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical lever and eccentric drive system with a direct drive mechanism. This substitution eliminates multiple articulation points and reduces frictional forces, thereby lowering power requirements while achieving the same movement output.

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

2Ease of operation

If a differential gear with lever mechanism is used, then the pilgrim-step movement is achieved, but the power requirements increase due to frictional forces at articulation points

Engineering Contradiction:
Improvemovement generationVSAvoidpower requirements
Core Design Contradiction:
Ease of operationVSPower

Solution Approach 1:

The patent removes the lever mechanism and eccentric drive components that create frictional losses. By directly driving the carrier, the system eliminates multiple articulation points where friction occurs, thereby reducing the power required to generate the pilgrim-step movement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the friction-prone mechanical lever and eccentric drive system with a direct drive mechanism. This substitution significantly reduces frictional forces at articulation points, leading to lower power requirements while maintaining the same operational output.

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

3Productivity

If a gear design with multiple components is used, then the movement is transmitted, but the load capacity limits are reached with increasing comb cycles

Engineering Contradiction:
Improvecomb cyclesVSAvoidload capacity
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent eliminates intermediate transmission components that add to the overall load on the system. By directly driving the carrier, the design reduces the cumulative load on each component, enabling the system to sustain higher comb cycles without reaching load capacity limits.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the multi-component transmission system with a direct drive mechanism. This substitution reduces the number of load-bearing articulation points and friction losses, thereby increasing the overall load capacity and enabling higher productivity with more comb cycles.

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

4Ease of operation

If a lever mechanism is used, then the pilgrim-step movement is generated, but the degree of freedom in designing the movement curve is limited

Engineering Contradiction:
Improvemovement generationVSAvoidmovement curve design freedom
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements a variable speed drive system that dynamically adjusts the rotational speed of the carrier. This dynamic control allows for flexible design and adjustment of the movement curve, providing greater adaptability and freedom in optimizing the pilgrim-step movement characteristics for different operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention enables adjustment of movement parameters such as speed, acceleration, and timing through the variable speed drive. This parameter flexibility allows for optimized movement curve design that can be adapted to different fabric types, production speeds, and quality requirements, significantly increasing design freedom.

Inventive Principle:
Principle #35Parameter changes

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 reduces torque loads, increases design freedom, and enables more efficient operation by optimizing the movement curve of the detaching rollers, allowing for higher comb cycles without overloading mechanical elements.

Implementation Method 1

a gear stage with non-circular gears, which converts a uniform rotary motion of a main drive into an irregular rotary motion

Methodology Applied
Scientific EffectNon-circular gear mechanism: Gear

Implementation Method 2

The carrier of the differential gear, in which the sun gears are rotatably mounted, is driven via a uniformly driven gear wheel

Methodology Applied
Scientific EffectDifferential gear mechanism: Epicyclic Gearing

Implementation Method 3

A non-uniform movement is transmitted to the differential gear axle and thus to a first sun gear connected to it via an eccentric drive, which is connected to a lever gear

Methodology Applied
Scientific EffectEccentric mechanism: Eccentric

Data Source

PatentEP2389463B1Drive apparatus for the draw-off rolls of a combing machine
Publication Date: 2013.08.14 MASCHINENFABRIK RIETER AG
  • EP2389463B1 patent drawingFigure 1
  • EP2389463B1 patent drawingFigure 2~4
  • EP2389463B1 patent drawingFigure 5~7

AI summary

The invention relates to a drive apparatus for generating a step-back movement for the draw-off rolls (A1, A2) of a combing machine, which are connected by drive means (Z1-Z3) to an output shaft (9) of a differential gear (1), the rotatably mounted web (2) of which is driven by at least one drive element (20, Z) driven at a constant rotational speed, wherein the differential gear (1) has a second gear stage (G2), which comprises a sun wheel (S2) fastened non-rotatably on the output shaft (9) and planet wheels (U4 to U6) mounted rotatably in the web (2) by way of shafts (33 to 35), and a first gear stage (G1) is provided, which comprises planet wheels (U1 to U3), each of which is arranged coaxially to the planet wheels (U4 to U6) of the second gear stage (G2) and fastened non-rotatably on the shafts (33 to 35) and have a drive connection to a further sun wheel (S1), which is fastened non-rotatably to a rotatably mounted drive shaft (5), which is driven by a drive unit (4, G3) in an irregular rotary motion. In order to optimize the curve of movement of the draw-off roll, while reducing the torque to be applied at the same time, it is proposed that the drive unit be formed by a gear stage (G3) having noncircular gear wheels (42, 43), which transforms a regular rotary motion of a main drive (HA) into an irregular rotary motion.