Hydraulic Motor Brake Layout for Compact Oscillation Locking

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Solution Overview

Problem

Existing hydraulic motors face challenges in reliably locking and unlocking oscillatory rotation, particularly due to the limited space for the brake mechanism, which can lead to increased load and size issues.

Innovation Solution

A hydraulic device with a brake mechanism that uses friction plates and a press mechanism to lock the oscillatory rotating body, where the friction plates are disposed around the rotation restricting shaft, allowing for efficient braking torque and reduced size, and automatic operation based on hydraulic fluid pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lock pin and lock hole mechanism is used to prevent unexpected rotation of the output rotatable block, then the oscillatory rotation can be restricted when the hydraulic motor is not in operation, but the brake mechanism cannot be disposed in a sufficient space, leading to increased overall size of the hydraulic motor

Engineering Contradiction:
Improvelocking reliabilityVSAvoidoverall size of hydraulic motor
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The brake mechanism is merged with the rotation restricting shaft by disposing the friction plates around the rotation restricting shaft. This integration allows the brake mechanism to utilize the existing space around the shaft, eliminating the need for separate locking components and reducing the overall size of the hydraulic motor while maintaining reliable locking function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The friction plates are nested around the rotation restricting shaft, with the brake mechanism components arranged in a concentric configuration. This nesting approach maximizes space utilization within the existing structure, allowing the brake mechanism to fit within the limited space without increasing the overall motor dimensions.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Volume of moving object

If the brake mechanism is disposed in limited space between the end surface of the oscillatory rotating body and the end wall of the motor case, then the overall size can be maintained, but the brake mechanism cannot produce sufficient braking torque

Engineering Contradiction:
Improveoverall size of hydraulic motorVSAvoidbraking torque
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The friction plates are arranged in a radial configuration around the rotation restricting shaft, utilizing the circumferential dimension rather than only the axial dimension. This dimensional change allows the brake mechanism to generate sufficient braking torque through the radial friction force while maintaining a compact axial profile, thus producing adequate force within limited space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If the lock pin is positioned to face the path described by the lock hole during oscillation, then the lock can engage and disengage, but enormous load is applied to the lock pin and periphery of the lock hole during locking and unlocking

Engineering Contradiction:
Improvelocking and unlocking operationVSAvoidload on lock pin
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The mechanical lock pin and lock hole system is replaced with a friction-based brake mechanism that uses friction plates and a press mechanism. This substitution eliminates the impact and enormous load associated with mechanical engagement and disengagement, providing smooth operation without concentrated stress on specific components. The friction-based system distributes the braking force across the friction plate surfaces rather than concentrating it on a single pin.

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

4Force

If friction plates are disposed around the rotation restricting shaft, then sufficient braking torque can be produced in a limited space, but the brake mechanism requires a press mechanism to activate

Engineering Contradiction:
Improvebraking torqueVSAvoidbrake mechanism structure
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The brake mechanism is designed to be automatically activated by the rotation restricting shaft itself. As the shaft rotates, it naturally engages with the friction plates through its geometric configuration, eliminating the need for a separate press mechanism. The rotational motion of the shaft self-generates the necessary friction force to produce braking torque, simplifying the overall brake mechanism structure while maintaining effective braking capability.

Inventive Principle:
Principle #25Self-service

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 solution enables smooth and reliable locking and unlocking of the oscillatory rotation, reducing the overall size of the hydraulic device while maintaining effective braking torque, and eliminates the need for manual operation of the brake mechanism.

Implementation Method 1

a press mechanism configured to press the first and second friction plates against each other

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the pressure of the hydraulic fluid produces a rotational force, which acts upon the oscillatory rotating body

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Data Source

PatentEP4375500A1Hydraulic device, hydraulic motor and construction machine
Publication Date: 2024.05.29 NABTESCO CORP
  • EP4375500A1 patent drawingFigure 1
  • EP4375500A1 patent drawingFigure 2
  • EP4375500A1 patent drawingFigure 3

AI summary

Hydraulic device (15, 15A, 115, 215, 215A, 315, 415, 515, 615) including a first block (18), a second block (16), an oscillatory rotating body (30), a rotation restricting shaft (32), a first friction plate (56, 356, 456, 71), a second friction plate (55, 355, 455, 70) and a press mechanism. The first block (18) has a plurality of internal teeth (22). The second block (16) is configured to rotate relative to the first block (18). The oscillatory rotating body (30) has a plurality of external teeth (30a) smaller in number than the internal teeth (22), is provided inside the first block (18) such that the oscillatory rotating body (30) is oscillatorily rotatable, and has an inner circumferential portion. The internal teeth (22) and the external teeth (30a) define a working chamber (35a, 35b) therebetween. The rotation restricting shaft (32) extends from the inner circumferential portion of the oscillatory rotating body (30) in a direction intersecting a radial direction. The rotation restricting shaft (32) couples the oscillatory rotating body (30) and the second block (16) such that the oscillatory rotating body (30) and the second block (16) are not allowed to rotate relative to each other while allowing the oscillatory rotating body (30) to oscillatorily rotate. The first friction plate (56, 356, 456, 71) is configured to rotate together with the oscillatory rotating body (30). The second friction plate (55, 355, 455, 70) is restricted from rotating by the second or first block (18, 16). The press mechanism is configured to press the first and second friction plates (56, 356, 456, 71, 55, 355, 455, 70) against each other.