Forestry Winch Ejector Roller Coupling for Plastic Rope
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Solution Overview
Problem
Forestry winches with steel ejector rollers are not suitable for plastic ropes due to poor power transmission values, leading to slipping and damage, as they cannot effectively transmit the required axial forces for low operating forces during unwinding.
Innovation Solution
A rotatable pressure roller is coupled to the ejector roller, with its outer peripheral surface pressing the plastic rope onto the groove base and end faces resting on the groove flanks, allowing for improved force transmission through a rotary coupling, enabling the use of a steel ejector roller and reducing wear and slipping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a steel ejector roller is used with a plastic rope, then the ejector roller can be made robust and durable, but the power transmission between the roller and rope becomes very poor, leading to slippage and damage
Solution Approach 1:
The ejector roller is constructed as a composite structure with a steel core for structural strength and a rubber coating for improved friction and power transmission. This allows the roller to maintain its robustness while achieving the necessary grip on the plastic rope to prevent slippage and damage.
Solution Approach 2:
The surface properties of the ejector roller are modified by adding a rubber coating, which changes the friction characteristics and material compatibility with the plastic rope. This parameter change enables effective power transmission without compromising the underlying steel structure's strength.
2Strength
If a steel ejector roller is used with a plastic rope, then the structural integrity is maintained, but slippage occurs quickly resulting in damage to the synthetic rope
Solution Approach 1:
The rubber-coated steel roller combines the structural integrity of steel with the high-friction surface properties of rubber, eliminating slippage between the roller and plastic rope while maintaining the necessary structural strength to handle operational loads.
Solution Approach 2:
Only the surface layer of the ejector roller is modified with rubber coating, providing localized high-friction contact with the plastic rope where needed, while the bulk steel structure maintains its structural integrity and strength.
3Force
If the ejector roller is made of steel for robustness, then it can handle high forces, but the force transmission to the plastic rope becomes insufficient for low operating forces
Solution Approach 1:
The rubber coating on the steel roller provides high friction contact with the plastic rope, enabling efficient force transmission from the motor-driven roller to the rope. This allows the system to handle high forces through the steel structure while transmitting sufficient force to the rope for easy operation.
Solution Approach 2:
The friction coefficient at the roller-rope interface is increased through the rubber coating, which improves the efficiency of force transmission. This parameter change enables the system to achieve low operating forces by effectively transferring the motor's force output to the plastic rope.
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 sufficient axial forces to be transferred to the plastic rope, reducing wear and enabling low operating forces for pulling, thus overcoming the limitations of steel ejector rollers with plastic ropes, ensuring safe and efficient unwinding and winding operations.
Implementation Method 1
the pressure roller is designed to dip into the receiving groove in such a way that the plastic rope is pressed onto the groove base by an outer circumferential surface of the pressure roller
Implementation Method 2
the pressure roller is rotatably coupled, wherein the driven ejector roller and the pressure roller are rotatably coupled
Data Source
Figure 1
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AI summary
The invention relates to an ejector (6) for a forestry winch (1), wherein the ejector (6) has a rotatable ejector roller (7) over which a plastic rope (4) is guided and deflected, the ejector roller (7) being driven by a drive motor (10). The ejector (6) has at least one rotatable pressure roller (10; 10a; 10b) by means of which the plastic rope (4) is pressed against the ejector roller (4), wherein the driven ejector roller (7) and the pressure roller (10; 10a; 10b) are rotatably coupled.