Spring-Loaded Damping Element for Hydraulic Brake Leakage Compensation

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Solution Overview

Problem

In passive accumulator-less hydraulic brake systems, leakage leads to pressure loss in the hydraulic circuit, necessitating frequent pump startups, causing wear and potentially motor failure, especially in systems with small-volume braking force generators and higher pressures.

Innovation Solution

A spring-loaded damping element is connected to the hydraulic circuit for intermediate buffering of a leakage compensation oil volume, allowing temporary storage of oil between restart and switch-off pressures, reducing the need for pump startups due to leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the hydraulic pump is activated frequently to compensate for leakage losses, then the pressure in the hydraulic circuit is maintained, but the wear of the motor and pump combination increases leading to potential failure

Engineering Contradiction:
Improvepressure maintenanceVSAvoidservice life of motor and pump
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The damping element is pre-filled with a leakage compensation oil volume (0.3 to 1 cm³) that is prepared in advance to compensate for leakage losses. This preliminary action allows the system to handle leakage without immediate pump activation, reducing wear while maintaining pressure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The spring-loaded damping element provides beforehand cushioning by storing a small volume of hydraulic oil that can be used to compensate for leakage. The spring element pre-absorbs pressure variations and provides a buffer that protects the pump from frequent activations caused by minor leakage.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Volume of moving object

If the brake force generator is made smaller with higher pressures, then the braking system becomes more compact, but leakage causes more significant pressure drops requiring frequent pump startups

Engineering Contradiction:
Improvebrake force generator sizeVSAvoidpressure stability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The damping element provides beforehand cushioning by storing a small volume of hydraulic oil (0.3 to 1 cm³) that can be used to compensate for leakage losses. The spring element pre-absorbs pressure variations and provides a buffer that protects the high-pressure system from frequent activations caused by minor leakage, which is particularly important in compact high-pressure systems.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The damping element acts as an intermediary between the brake force generator and the hydraulic pump. It mediates the pressure variations caused by leakage in the compact high-pressure system, providing a buffer that prevents direct transmission of pressure drops to the pump, thereby reducing frequent startups.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If spring elements in the brake force generator are used, then the brake force generator characteristics are maintained, but the spring elements relax over time causing the force generator to become weaker

Engineering Contradiction:
Improvebrake force generator characteristicsVSAvoidservice life of brake force generator
Core Design Contradiction:
Stability of the object's compositionVSDuration of action of stationary object

Solution Approach 1:

The damping element provides feedback by monitoring pressure variations in the hydraulic circuit. When pressure drops due to leakage or spring relaxation, the damping element responds by releasing stored oil volume, which compensates for the pressure loss and maintains stable brake force generator characteristics over time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The damping element with spring-loaded piston provides self-service by automatically compensating for pressure losses without external intervention. The spring element expands or contracts based on pressure conditions, self-regulating the leakage compensation oil volume delivery to maintain system performance.

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 damping element effectively compensates for leakage losses, reducing wear and extending the service life of the motor and pump combination by maintaining sufficient oil volume and stabilizing the braking force generator's characteristics.

Implementation Method 1

a spring-loaded damping element for intermediate buffering of a leakage compensation oil volume is connected in the pressure line of the hydraulic circuit

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

a cylinder chamber for the leakage compensation oil volume is formed in the damping element between a cylinder head and a spring-loaded piston

Methodology Applied
Scientific EffectHydraulic pressure buffering: Hydraulic Accumulator

Data Source

PatentEP3661822B1Passive accumulator-free hydraulic braking system
Publication Date: 2023.03.15 KNORR BREMSE SYST FUR SCHIENENFAHRZEUGE GMBH
  • EP3661822B1 patent drawingFigure 1~2

AI summary

The invention relates to a passive accumulator-free hydraulic braking system in which a hydraulic pump (2) driven by a motor (1) generates an oil pressure that feeds a pressure line (5) of a hydraulic circuit (6) via a check valve (4), the pressure line (5) supplying a hydraulic feed pressure to at least one brake caliper (10) that is connected thereto. A spring-biased damping element (12) for temporarily buffering a leakage-compensating oil volume is connected to the pressure line (5) of the hydraulic circuit (6).