Crane Motor Brake Control for Constant Load Lowering

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Solution Overview

Problem

Existing work machines use hydraulic brakes to control the lowering of loads, which result in noise pollution and increased fuel consumption due to the conversion of braking energy into heat.

Innovation Solution

Utilize the motor brake of the internal combustion engine to control the lowering speed of loads, eliminating the need for hydraulic brakes and reducing noise and fuel consumption by converting braking energy through compression and decompression work.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hydraulic brakes are used to control load lowering, then controlled lowering is achieved, but noise pollution increases due to high-speed fan operation

Engineering Contradiction:

Improvecontrolled loweringVSAvoidnoise pollution

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the hydraulic braking system with an electric motor braking system. The motor's electromagnetic braking capability is utilized to control the lowering speed, eliminating the need for hydraulic pumps, pressure stages, and high-speed cooling fans, thereby significantly reducing noise pollution while maintaining controlled lowering

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the noisy hydraulic cooling fan system from the load lowering control process. By using the motor's inherent braking capability, the system eliminates the need for separate hydraulic braking components and their associated cooling mechanisms, directly addressing the noise issue

Inventive Principle:

Principle #2Taking out (Extraction)

2Power

If hydraulic brakes with brake pumps are used, then braking power is generated, but fuel consumption increases due to motor operation in lowering mode

Engineering Contradiction:

Improvebraking powerVSAvoidfuel consumption

Core Design Contradiction:

PowerVSUse of energy by moving object

Solution Approach 1:

The patent converts the potentially harmful effect of the motor running during lowering operations into a beneficial braking mechanism. By controlling the motor to operate in generator mode during lowering, the system recovers energy that would otherwise be lost, converting the motor's rotational energy into useful braking power while reducing fuel consumption

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The motor serves dual functions: it both drives the cable winch during lifting and provides braking during lowering. This self-service capability eliminates the need for separate braking systems and reduces overall energy consumption by utilizing the motor's own energy output for braking purposes

Inventive Principle:

Principle #25Self-service

3Reliability

If hydraulic brakes are used, then load lowering control is achieved, but thermal load on hydraulic system increases due to heat generation

Engineering Contradiction:

Improvelowering controlVSAvoidthermal load

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent replaces the hydraulic braking system that generates thermal load on hydraulic oil with an electric motor braking system. The motor's electromagnetic braking converts kinetic energy directly into electrical energy or dissipates it through regenerative braking, avoiding the thermal load issues associated with hydraulic fluid heating

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Reduces noise pollution and fuel consumption by using the motor brake to control load lowering, minimizing thermal load on the hydraulic system and improving control accuracy.

Implementation Method 1

reducing noise and fuel consumption by converting braking energy through compression and decompression work

Methodology Applied

Scientific EffectCompression and decompression work: Compression

Data Source

PatentUS20250243038A1Working machine, in particular crane, with motor brake

Publication Date: 2025.07.31 LIEBHERR WERK EHINGEN

AI summary

The disclosure relates to a work machine, in particular crane, comprising a cable winch, by means of which a cable can be wound up for lifting a load and unwound for lowering the load, a motor, by means of which the cable winch can be driven, and a controller, by means of which the motor can be controlled, wherein the motor comprises a braking device for generating a braking torque counteracting an externally generated torque. According to the disclosure, when the load is lowered as a function of a predetermined target braking torque and a braking torque that can be provided by the motor, the controller is configured to control the braking device and to control the motor in such a way that the load is lowered at a predetermined and, in particular, constant speed. The disclosure also relates to a method for lowering a load by means of a work machine according to the disclosure and to a corresponding computer program product.