Integrated Low-Pressure Unit for Compact Hydraulic Drive Boosting

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Solution Overview

Problem

Conventional hydraulic drives require an external aggregate and additional piping or hoses to raise the pressure level, which reduces compactness, increases maintenance complexity, and is inefficient.

Innovation Solution

A low-pressure unit integrated with a hydraulic drive, featuring a tank pressure memory, a low-pressure memory, and a motor-driven pump, connected via a hydraulic coupling block, allowing direct integration and eliminating the need for external aggregates and hoses, with switching valves for closed or open system operation and a check valve to prevent backflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an external unit is used to raise pressure level in hydraulic drive, then pressure adjustment capability is improved, but device complexity and space requirements increase

Engineering Contradiction:
Improvepressure adjustment capabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the pressure-raising unit with the hydraulic drive by integrating the pump into the existing hydraulic circuit. The pump is connected to the hydraulic drive through hydraulic coupling, allowing the pressure adjustment function to be merged with the main hydraulic system rather than operating as a separate external unit. This reduces overall system complexity while maintaining pressure adjustment capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hydraulic pump serves multiple functions: it raises the pressure level in the hydraulic drive while also being integrated into the existing hydraulic circuit. The pump can operate in different modes (closed circuit and open circuit) depending on system requirements, providing universal functionality that reduces the need for additional specialized components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If an external unit with piping or hoses is used, then pressure level can be raised, but compactness is reduced

Engineering Contradiction:
Improvepressure raising capabilityVSAvoidsystem compactness
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The pump and its hydraulic connections are integrated directly into the hydraulic drive's existing circuitry. The pump is hydraulically coupled to the hydraulic drive through the existing hydraulic fluid, eliminating the need for separate external piping or hoses. This merging of components significantly improves system compactness while maintaining the pressure raising capability.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If external piping or hoses are used for fluid supply, then pressure adjustment is enabled, but maintenance complexity increases

Engineering Contradiction:
Improvefluid supply capabilityVSAvoidmaintenance complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of repair

Solution Approach 1:

The pump is integrated into the hydraulic drive's internal circuit, eliminating external piping and hoses that would require maintenance. The hydraulic coupling uses the existing hydraulic fluid path within the drive, reducing the number of external connection points and potential failure sites. This integration significantly reduces maintenance complexity while maintaining fluid supply capability.

Inventive Principle:
Principle #5Merging (Combining)

4Stress or pressure

If an external aggregate is used, then pressure level can be increased, but installation space and effort increase

Engineering Contradiction:
Improvepressure levelVSAvoidinstallation space
Core Design Contradiction:
Stress or pressureVSArea of stationary object

Solution Approach 1:

The pressure-raising pump is merged with the hydraulic drive system, utilizing the existing space and mounting structure of the hydraulic drive. The pump is hydraulically coupled to the drive through internal connections, eliminating the need for separate external mounting space and reducing overall installation footprint while maintaining the ability to increase pressure levels.

Inventive Principle:
Principle #5Merging (Combining)

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

This configuration enhances compactness, reduces maintenance, ensures consistent pressure, and allows for efficient pressure adjustment and fluid management within the hydraulic drive, enabling simpler service and energy savings.

Implementation Method 1

a tank pressure accumulator (2) for storing a fluid (pressure medium) at a desired pressure

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a pump (4) which conveys the fluid from the tank pressure accumulator (2) into a low-pressure accumulator (3)

Methodology Applied
Scientific EffectHydraulic pump: Pump

Implementation Method 3

The pump (4) has a check valve which prevents the fluid from flowing back from the low-pressure accumulator (3) to the pump (4)

Methodology Applied
Scientific EffectCheck valve: Valve

Data Source

PatentEP4253766B1System with low pressure unit and external tank for increasing a pressure level in a hydraulic drive and corresponding system with a hydraulic drive
Publication Date: 2025.01.29 ROBERT BOSCH GMBH
  • EP4253766B1 patent drawingFigure 1~2
  • EP4253766B1 patent drawingFigure 3
  • EP4253766B1 patent drawingFigure 4

AI summary

The invention relates to a low-pressure unit (1) for raising a pressure level in a hydraulic drive (8). The low-pressure unit (1) comprises a tank pressure accumulator (2) for storing a hydraulic fluid at a desired pressure, a low-pressure accumulator (3) downstream of the tank pressure accumulator (2) for intermediate storage of the fluid, and a hydraulic pump (4) driven by a motor (5). According to the invention, the tank pressure accumulator (2), the low-pressure accumulator (3), and the pump (4) are hydraulically coupled to one another via a connecting block (6), and the connecting block (6) is designed such that the low-pressure unit (1) can be directly integrated into or connected to a main control block of the hydraulic drive (8) via the connecting block (6), or is already integrated into or connected to it.