Hydraulic Pump Combination for Drum Speed

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Solution Overview

Problem

Hydraulic systems in vehicles and equipment often require separate closed-loop and open-loop fluid circuits, leading to inefficiencies due to the underutilization of pump capacity and the need for larger pumps to handle varying operational demands, such as rotating transit mixer drums and auxiliary equipment.

Innovation Solution

A combination open- and closed-loop hydraulic system that allows for the selective connection and disconnection of pumps between fluid circuits using a control manifold and valve system, enabling the sharing of pump output to increase drum motor speed and allocate flow as needed between drum rotation and auxiliary functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a large pump is used to rotate the mixer drum at high speed, then the drum can achieve high speed rotation for mixing and cleaning, but the pump capacity is underutilized during low speed transit rotation

Engineering Contradiction:
Improvedrum rotation speedVSAvoidpump capacity underutilization
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The hydraulic system is segmented into two separate fluid circuits: a first fluid circuit with a first pump dedicated to drum rotation, and a second fluid circuit with a second pump for auxiliary equipment. This segmentation allows each pump to be optimized for its specific function and operating range, preventing the underutilization that would occur if a single large pump had to handle both high-speed mixing and low-speed transit requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control manifold enables the second pump to serve dual functions: it can independently drive auxiliary equipment through the second fluid circuit, or it can be selectively connected to the first fluid circuit to assist the first pump in driving the drum motor. This multi-functionality allows the system to flexibly allocate pump capacity based on operational demands, optimizing energy utilization across different operating modes.

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

2Adaptability or versatility

If separate closed-loop and open-loop fluid circuits are used, then each circuit can operate independently for its specific function, but the system complexity increases with multiple pumps and control mechanisms

Engineering Contradiction:
Improvecircuit independenceVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The control manifold merges the first and second fluid circuits by providing a common connection point that allows selective hydraulic coupling between the first pump and the drum motor. When the second pump is not needed for auxiliary equipment, it can be directed to assist the first pump through the manifold, effectively combining pump outputs to drive the drum motor at higher speeds without requiring a third dedicated pump.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control manifold acts as an intermediary device that mediates between the first pump, second pump, drum motor, and auxiliary equipment. It provides intelligent flow distribution and selective connection/disconnection capabilities, allowing the system to dynamically reconfigure hydraulic pathways based on operational requirements while maintaining circuit independence when needed.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a single pump is used for both drum rotation and auxiliary equipment, then system complexity is reduced, but the pump cannot efficiently handle varying flow demands of different functions

Engineering Contradiction:
Improvenumber of pumpsVSAvoidflow allocation efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The system employs dynamic flow allocation where the control manifold can reconfigure hydraulic connections in real-time based on operational demands. The second pump can dynamically switch between driving auxiliary equipment independently and assisting the first pump in driving the drum motor, allowing the system to adapt flow distribution to match varying productivity requirements of different functions without being constrained by a fixed single-pump architecture.

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

This configuration optimizes pump usage by allowing higher flow rates and flexible speed control, reducing energy consumption and extending the operational life of equipment by preventing concrete hardening during transit and enabling efficient mixing and cleaning.

Implementation Method 1

A first pump and a second pump are selectively connectable to fluid circuits that drive a drum motor and auxiliary equipment of a vehicle, respectively

Methodology Applied
Scientific EffectHydraulic fluid flow control: Hydraulic Press

Data Source

PatentEP2751433B1Hydraulic systems utilizing combination open-and closed-loop pump systems
Publication Date: 2018.03.21 EATON CORP
  • EP2751433B1 patent drawingFigure 1
  • EP2751433B1 patent drawingFigure 2
  • EP2751433B1 patent drawingFigure 3

AI summary

A pump system includes a closed-loop fluid circuit and an open-loop fluid circuit. The closed-loop fluid circuit includes a motor for rotating a first component connected to the closed-loop fluid circuit. A closed-loop pump drives the motor up to a first maximum rotational speed. The open-loop fluid circuit includes an open- loop pump for driving a second component connected to the open-loop fluid circuit. A control circuit includes a control valve for switching the outflow from the open- loop pump. The control valve selectively connects the open-loop pump to the closed-loop fluid circuit and simultaneously disconnects the open-loop pump from the open-loop fluid circuit. When the open-loop pump is connected to the closed- loop circuit, the closed-loop pump and the open-loop pump drive the motor at a second rotational speed greater than the first maximum rotational speed.