Hydraulic Shovel Pump Layout for Low-Loss Multi-Actuator Speed Control

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Solution Overview

Problem

Existing hydraulic shovel systems face challenges in maintaining adequate speed for the boom, arm, and bucket during complex operations due to insufficient hydraulic oil flow rates, leading to slowed motion and increased pressure loss.

Innovation Solution

The system employs three independent hydraulic pumps, where the first pump is connected to the bucket and boom actuators, the second pump is connected to the arm and boom actuators for speed increase, and the third pump is dedicated to arm speed increase, allowing for separate and efficient control of hydraulic oil flow to each actuator, minimizing pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If control valves are arranged in tandems along center bypass lines, then the system structure is simplified, but the downstream control valve cannot receive sufficient hydraulic oil flow rate when the upstream control valve is operated with large stroke

Engineering Contradiction:
Improvecontrol valve arrangementVSAvoidhydraulic actuator motion speed
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The patent divides the hydraulic system into multiple independent pump units (first pump, second pump, third pump), each capable of independently supplying hydraulic oil to different actuators. This segmentation allows each pump to provide sufficient flow rate to its designated actuator without being constrained by tandem valve arrangements, thereby resolving the contradiction between simplified structure and adequate motion speed.

Inventive Principle:
Principle #1Segmentation

2Speed

If a parallel line is added to bypass the upstream control valve, then the downstream control valve receives sufficient hydraulic oil flow rate, but the flow rate becomes biased toward the downstream actuator causing the upstream actuator to operate abnormally

Engineering Contradiction:
Improvedownstream actuator motion speedVSAvoidupstream actuator operation
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent assigns different pumps to different actuators (first pump to boom actuator, second pump to arm actuator, third pump to bucket actuator), creating independent hydraulic supply channels. This segmentation eliminates flow rate bias issues because each actuator receives hydraulic oil from its dedicated pump, ensuring both adequate motion speed and reliable operation without requiring complex parallel line configurations with throttles.

Inventive Principle:
Principle #1Segmentation

3Reliability

If a throttle is added to the parallel line to restrict flow rate, then the upstream actuator can operate normally, but the pressure loss on the meter-in side increases significantly

Engineering Contradiction:
Improveupstream actuator operationVSAvoidpressure loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent eliminates the need for throttles by providing dedicated pumps for each actuator. The first pump supplies the boom actuator, the second pump supplies the arm actuator, and the third pump supplies the bucket actuator independently. This segmentation removes the requirement for flow rate restriction devices, thereby avoiding the significant pressure losses that would otherwise occur on the meter-in side while maintaining reliable upstream actuator operation.

Inventive Principle:
Principle #1Segmentation

4Speed

If multiple pumps are used to supply hydraulic oil to multiple actuators, then each actuator can receive sufficient flow rate, but the system complexity increases

Engineering Contradiction:
Improveactuator motion speedVSAvoidhydraulic pump configuration
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent employs a multi-functional hydraulic control architecture where pumps and control valves can serve multiple purposes. The control valves are configured to control different actuators based on operational requirements, and the pumps can supply hydraulic oil to various actuators as needed. This multi-functionality allows the system to achieve adequate flow rate for each actuator while managing overall system complexity through flexible, adaptable configuration rather than rigid, dedicated connections.

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

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 enables the boom, arm, and bucket to operate at suitable speeds during complex operations without significant pressure loss, ensuring efficient and balanced hydraulic actuation.

Implementation Method 1

a first pump 31, a second pump 32, and a third pump 33, each pump being a hydraulic pump driven by an engine 30

Methodology Applied
Scientific EffectHydraulic pump: Pump

Implementation Method 2

a boom cylinder 24, an arm cylinder 26, and a bucket cylinder 28 which are respective hydraulic actuators for the boom, arm, and bucket

Methodology Applied
Scientific EffectHydraulic actuator: Hydraulic Press

Implementation Method 3

a hydraulic circuit... configured to supply the hydraulic oil from the first pump to the boom hydraulic actuator and the bucket hydraulic actuator

Methodology Applied
Scientific EffectHydraulic transmission: Hydraulic Press

Data Source

PatentEP2980325B1Hydraulic shovel
Publication Date: 2021.08.25 KOBE STEEL LTD
  • EP2980325B1 patent drawingFigure 1
  • EP2980325B1 patent drawingFigure 2
  • EP2980325B1 patent drawingFigure 3

AI summary

Provided is a hydraulic shovel capable of moving a boom, an arm, and a bucket at respective adequate speeds even during complex operations thereof, without a significant pressure loss. This hydraulic shovel includes: a first pump (31) connected to a boom actuator (24) and a bucket actuator (28); a second pump (32) connected to an arm actuator (26) and the boom actuator (24); a third pump (33) connect to the arm actuator (26); a boom control valve (54) interposed between the first pump (31) and the boom actuator (24); an arm control valve (56) interposed between the second pump (32) and the arm actuator (26); a bucket control valve (58) interposed between the first pump (31) and the bucket actuator (28); a boom merging valve (55) for speed increase interposed between the second pump (32) and the boom actuator (24); and an arm merging valve (57) for speed increase interposed between the third pump (33) and the arm actuator (26).