Winch Torque Control via Independent Drum Drive

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Solution Overview

Problem

Cable winches, particularly electric rescue winches, face challenges in efficiently managing torque to prevent cable slippage and reduce wear on mechanical components, often requiring complex clutch systems that can be prone to failure and increased maintenance.

Innovation Solution

Implementing a control strategy that uses two independent electric drives for the capstan and cable drum, allowing for adjustable torque on the cable drum based on speed differences detected by a speed measuring device, eliminating the need for a slipping clutch and optimizing operation by maintaining cable tension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rigid coupling between the drum and capstan drive is used, then the structure is simple, but cable slippage cannot be prevented and wear increases

Engineering Contradiction:
Improvecable grip reliabilityVSAvoiddrive system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The drive system is segmented into two independent drives: a main drive for the capstan and a drum drive for the cable drum. This segmentation allows each drive to be optimized independently, with the drum drive providing controlled torque to prevent cable slippage without requiring a complex coupling mechanism between the drives.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the torque parameter of the drum drive based on detected cable slippage conditions. When slippage is detected through speed comparison, the control unit increases the drum drive torque to compensate and prevent further slippage, adapting the system behavior to changing operational conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a slip clutch is used to compensate speed differences, then cable slippage is prevented, but the slip clutch experiences wear and requires maintenance

Engineering Contradiction:
Improvecable slippage preventionVSAvoidmaintenance requirements
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The slip clutch component is completely removed from the system. Instead of using a mechanical slip clutch to compensate for speed differences, the patent employs an independent drum drive with electronic control that actively prevents cable slippage through torque adjustment, eliminating the wear-prone mechanical component.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical slip clutch is replaced with an electronically controlled drum drive system. The control unit monitors cable speed and adjusts drum drive torque electronically, substituting mechanical friction-based slip compensation with electronic control and active torque management.

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

3Reliability

If high torque is applied to the cable drum, then cable tension is maintained and slippage prevented, but wear on mechanical components increases

Engineering Contradiction:
Improvecable tension maintenanceVSAvoidmechanical component wear
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system implements feedback control by continuously monitoring the actual cable speed via the speed measuring device and comparing it with the commanded cable speed. Based on this feedback and the detected speed difference indicating slippage, the control unit adjusts the drum drive torque to maintain adequate cable tension while minimizing excessive torque application.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The drum drive torque is made dynamic rather than fixed. The control unit continuously adjusts the torque level based on real-time operational conditions and detected slippage, applying only the necessary torque to prevent slippage rather than constantly applying high torque, thereby reducing mechanical wear.

Inventive Principle:
Principle #15Dynamics

4Reliability

If the winch operates at non-optimal points, then the system is simpler to control, but rope wear and mechanical component wear increase

Engineering Contradiction:
Improverope and component longevityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control system uses feedback from the speed measuring device to continuously monitor actual cable speed and compare it with the commanded speed. This feedback enables the control unit to detect deviations from optimal operation and adjust the drum drive torque accordingly, maintaining optimal operating conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Complex mechanical control mechanisms for maintaining optimal operating points are replaced with electronic control. The control unit processes speed information and dynamically adjusts drum drive torque, providing precise control of operating conditions without complex mechanical linkages or control devices.

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

Data Source

PatentEP3319899B1Winch, method for controlling operation of a winch and method for operating a winch
Publication Date: 2023.03.22 JENOPTIK ADVANCED SYST GMBH
  • EP3319899B1 patent drawingFigure 1
  • EP3319899B1 patent drawingFigure 2
  • EP3319899B1 patent drawingFigure 3~4

AI summary

A method for controlling operation of a winch (100) is proposed. In this case, the method is executable in conjunction with a winch (100) which has a capstan drive unit (110) for hauling a cable (105) into the winch (100) and for paying the cable (105) out of the winch (100), a main drive (115) for driving the capstan drive unit (110), a cable drum (120) for receiving the cable (105) by winding up and unwinding the cable (105), a drum drive (125) for driving the cable drum (120), wherein the drum drive (125) and the main drive (115) are operable independently of one another, and a rotational speed measuring device (130) which is arranged in a cable inlet portion of the winch (100). The method has a step of reading a first rotational speed (152) from the main drive (115) and a second rotational speed (154) from the rotational speed measuring device (130). In addition, the method has a step of determining a torque value for setting a torque of the drum drive (125) depending on the first rotational speed (152) and the second rotational speed (154).