Pneumatic-Servo Hydraulic Unit for Low-Noise Intermittent Pumping

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Solution Overview

Problem

Conventional hydraulic units face issues with high electric energy consumption, noise generation, heat buildup, and mechanical wear due to continuous operation of electric motors and metal-to-metal contact in hydraulic pumps, leading to inefficiencies and increased maintenance needs.

Innovation Solution

A hydraulic unit combining a pneumatic cylinder and servomotor with a ball screw mechanism that uses compressed air to drive a hydraulic plunger, reducing energy consumption and noise, and eliminating metal-to-metal contact by using a pneumatic system that only pumps oil when needed, storing it in a pressure accumulator for efficient use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If electric motors are used to continuously drive hydraulic pumps, then hydraulic actuators can be controlled and moved, but electric energy consumption increases significantly

Engineering Contradiction:
Improvecontrol and movement of hydraulic actuatorsVSAvoidelectric energy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent replaces continuous electric motor operation with periodic pneumatic cylinder activation. The pneumatic cylinder drives the hydraulic pump only when hydraulic actuators need to move, eliminating continuous energy consumption. The system uses compressed air to activate the pneumatic cylinder at specific intervals rather than maintaining constant operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent substitutes the electric motor-driven mechanical system with a pneumatic system. Instead of using electric motors to continuously drive hydraulic pumps, the invention uses compressed air to activate pneumatic cylinders, which then mechanically drive the hydraulic pumps only when needed, replacing the continuous electrical-mechanical system with an intermittent pneumatic-mechanical system.

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

2Productivity

If hydraulic pumps operate continuously to pump oil to the system, then hydraulic actuators can function, but heat generation increases due to oil attrition

Engineering Contradiction:
Improvehydraulic actuator functionalityVSAvoidoil temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent implements periodic pumping action instead of continuous operation. The pneumatic cylinder activates the hydraulic pump only when hydraulic actuators require movement, creating intermittent pumping cycles. This reduces the total time oil is being pumped and circulated, thereby reducing the cumulative heat generation from oil attrition during suction and compression.

Inventive Principle:
Principle #19Periodic action

3Power

If hydraulic pumps use metal-to-metal contact in moving parts, then pumping action is achieved, but noise generation increases

Engineering Contradiction:
Improvepumping actionVSAvoidnoise
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent introduces pneumatic elements (pneumatic cylinder with compressed air) into the system to drive the hydraulic pump. This pneumatic activation mechanism replaces or supplements traditional direct mechanical coupling, using gas pressure to drive the pumping action. This reduces metal-to-metal contact noise by introducing a pneumatic intermediary in the power transmission chain.

Inventive Principle:
Principle #29Pneumatics and hydraulics

4Power

If metal parts are in permanent contact in hydraulic pumps, then pumping function is maintained, but wear of metal parts and release of solid particles increases

Engineering Contradiction:
Improvepumping functionVSAvoidmetal part wear and solid particle release
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent uses compressed air in the pneumatic cylinder to drive the hydraulic pump mechanism. This pneumatic drive reduces the frequency and intensity of metal-to-metal contact compared to continuous mechanical driving. The pneumatic activation creates controlled, intermittent motion that reduces wear on metal components and minimizes the release of solid particles into the hydraulic system.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 solution achieves up to 90% savings in electric energy consumption, significantly reduces noise and oil volume, maintains low oil temperature without heat exchangers, and extends equipment lifespan by minimizing attrition and leaks, creating a more efficient and quieter operation.

Implementation Method 1

pneumatic cylinder (15) that works jointly with a servomotor (M), which receives torque to turn the ball screw (29), with the objective of moving a differentiated hydraulic piston pump

Methodology Applied
Scientific EffectPneumatic pressure: Pressure Increase

Implementation Method 2

ball screw (29), which will receive torque from the servomotor (M) to turn clockwise and counter-clockwise, with the objective of displacing the hydraulic plunger (7) upward and downward

Methodology Applied
Scientific EffectBall screw mechanism: Screw

Implementation Method 3

hydraulic pumps are generally large in size and pump oil to the system on a continuous basis

Methodology Applied
Scientific EffectHydraulic pumping: Pump

Implementation Method 4

the pumped oil goes into a hydraulic pressure accumulator (25), where it remains idle to be used when required

Methodology Applied
Scientific EffectHydraulic pressure accumulation: Hydraulic Accumulator

Data Source

PatentEP3875781B1Hydraulic unit with combined pneumatic/servomotor action and related use
Publication Date: 2024.04.24 DRAUSUISSE BRASIL COMML E LOCACAO DE UNIDADES HIDRAULICAS INTELIGENTES SA
  • EP3875781B1 patent drawingFigure 1
  • EP3875781B1 patent drawingFigure 2

AI summary

The present patent of invention relates to a hydraulic unit (U) with a pneumatic cylinder (15) that works jointly with a servomotor (M), together with a ball screw (29) to together move a hydraulic piston pump (8), made up of a hydraulic plunger (7), with related sealing elements to prevent oil leaks, noise, metal-on-metal attrition and loss of efficiency, that is moved upwards and downwards using a ball screw (29) and a pneumatic cylinder (15), jointly with a servomotor (M) which, when moved, pushes the pressurized oil outwards while filling the opposite hydraulic chamber with an oil suction movement, the pumped oil entering a hydraulic pressure accumulator (25), where it remains idle to be used when required and being supplied by the up/down movement of the piston, generating continuous pumping, which is automatically stopped when the hydraulic pressure accumulator (25) is full and has reached the predetermined hydraulic pressure. With regard to the field of application, the invention is intended to be used to move hydraulic actuators in a variety of different machines and equipment.