Hydraulic Brake Trigger Mechanism for Selective Motor Braking

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Solution Overview

Problem

Hydraulic brake systems for hydraulic motors often fail to provide proper braking under varying operating conditions, leading to unwanted motion due to momentum after pressurized hydraulic input is removed, and may apply brakes during conditions where braking is not desired.

Innovation Solution

A hydraulic brake mechanism with a trigger mechanism that detects flow changes from the power source, preventing braking during conditions of reduced flow but not complete shutdown, and applying a load only when flow is completely stopped, ensuring proper braking during intended conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hydraulic brake is supplied to overcome momentum and stop the motor after pressurized hydraulic input is removed, then the motor can be stopped effectively, but the brake may apply under conditions where braking is not desired (such as during flow reductions)

Engineering Contradiction:
Improvebraking reliabilityVSAvoidinadvertent braking
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a trigger mechanism that continuously monitors hydraulic fluid flow from the power source and provides feedback control to the brake mechanism. When flow is completely stopped, the trigger activates the brake; when flow is merely reduced but still present, the brake remains disengaged. This feedback-based control resolves the contradiction by ensuring the brake only activates under the specific condition of complete flow shutdown, preventing inadvertent braking during partial flow reductions while maintaining reliable stopping capability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The trigger mechanism serves as an intermediary between the hydraulic fluid flow and the brake mechanism. It detects the flow status and translates it into appropriate brake activation signals. This intermediary component prevents direct coupling between flow variations and brake activation, allowing the system to distinguish between complete flow shutdown (requiring braking) and partial flow reduction (not requiring braking), thereby eliminating unwanted brake engagement.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Speed

If the brake mechanism responds to any flow reduction, then it can stop the motor quickly, but it will cause unwanted motion loss during normal operation with reduced flow

Engineering Contradiction:
Improvebraking speedVSAvoidoperational continuity
Core Design Contradiction:
SpeedVSProductivity

Solution Approach 1:

The trigger mechanism provides selective feedback control by monitoring whether flow is completely stopped or merely reduced. It activates the brake only when flow ceases entirely, while allowing the motor to continue operating during partial flow reductions. This selective feedback ensures rapid stopping when needed without causing unwanted motion loss during normal operational variations, thus maintaining productivity.

Inventive Principle:
Principle #23Feedback

3Reliability

If the brake mechanism is always engaged to prevent momentum rotation, then the motor will not rotate after input removal, but it will interfere with normal operation and cause energy loss

Engineering Contradiction:
Improvemomentum controlVSAvoidenergy loss during operation
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The brake mechanism transitions from a static always-engaged state to a dynamic condition-based state. The trigger mechanism dynamically controls brake engagement based on real-time flow detection: the brake is disengaged during normal operation (including reduced flow conditions) to allow free motor rotation without energy loss, and automatically engaged only when flow is completely stopped to control momentum. This dynamic control resolves the contradiction between momentum control and energy efficiency.

Inventive Principle:
Principle #15Dynamics

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

The hydraulic brake mechanism effectively prevents inadvertent braking during flow reductions and ensures proper braking when hydraulic flow is shut off, enhancing the performance of hydraulic systems by maintaining operation and avoiding momentum loss.

Implementation Method 1

The trigger mechanism is configured to detect flow of hydraulic fluid from the power source

Methodology Applied
Scientific EffectFlow detection:

Implementation Method 2

The hydraulic brake is movable between a non-braking position and a braking position in which the hydraulic brake is configured to apply a load for slowing the hydraulic motor

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 3

Hydraulic motors are designed to receive a pressurized hydraulic input from a power source and convert it into a rotational output to perform a work task

Methodology Applied
Scientific EffectHydraulic motor conversion:

Implementation Method 4

Once a hydraulic motor begins to rotate after introduction of the pressurized hydraulic input, it will continue to rotate for a period of time after the pressurized hydraulic input is removed due to momentum of the motor

Methodology Applied
Scientific EffectMomentum: Inertia

Data Source

PatentEP3068951B1Hydraulic brake
Publication Date: 2023.04.19 DOOSAN BOBCAT NORTH AMERICA INC
  • EP3068951B1 patent drawingFigure 1
  • EP3068951B1 patent drawingFigure 2~3
  • EP3068951B1 patent drawingFigure 4

AI summary

A hydraulic brake mechanism (145; 245; 345) for use in hydraulic systems (200; 300) to provide braking of a hydraulic motor (150; 250; 350) is disclosed. The brake mechanism provides proper braking under a range of operating conditions, including (1) the start of flow from the pump (205; 305) to the brake and motor and braking is not desired; (2) operating conditions in which constant flow is provided from the pump to the brake and motor and braking is not desired; (3) operating conditions in which abrupt decreases of flow from the pump to the brake and the motor occur, for example where flow is reduced due to being drawn by another work element (325) or hydraulic load, but under which a reduced supply flow is still present and braking is not desired; and (4) operating conditions in which the hydraulic flow from the pump to the brake mechanism and the motor is shut off completely and braking is desired.