The Modern Direct-Hydraulic System

1946 ◽  
Vol 154 (1) ◽  
pp. 178-208 ◽  
Author(s):  
F. H. Towler
Keyword(s):  
Hydraulic System ◽  
High Speed ◽  
Hydraulic Press ◽  
Hydraulic Pressure ◽  
Hydraulic Pump ◽  
Hydraulic Power ◽  
The Press ◽  
Hydraulic Accumulator ◽  
Work Done ◽  
Full Pressure

The first hydraulic press invented by Joseph Bramah in 1795 employed the direct-hydraulic system; i.e. hydraulic pressure was directly supplied to the press cylinder by a hydraulic pump and, therefore, the pressure exerted by the press ram was directly proportional to the pressure supplied by the pump, and the speed of the press ram was directly proportional to the delivery of the pump. Later developments in the use of hydraulic power resulted in the invention of the hydraulic accumulator to store liquid under pressure. With the accumulator system the speed and pressure exerted by the press ram are not controlled by the pump, and in fact they cannot be controlled with any precision; also there is considerable wastage of power when the press ram is operating at less than full pressure. The advent of the high-speed reciprocating ram pump has produced the modern direct-hydraulic system in which the press and pump form one self-contained unit. The power to drive the pump is in direct proportion to the work done by the press, and the speed and pressure exerted by the press ram can be precisely controlled. The author considers that a saving of at least 75 per cent in electric power can be made by conversion from the accumulator system to the direct-hydraulic system. Indicator diagrams are reproduced in the paper to show the saving in power which can be achieved by the direct-hydraulic system, and a comparison is made between the power consumption, in kilowatt-hours, of a direct-hydraulic cartridge-drawing press and a mechanical double-rack press doing the same operation. The paper includes a number of illustrations of direct-hydraulic presses, ranging from those of Bramah to present-day types.

Switchmode Hydraulic Power Supply Theory

2005 ◽  
Author(s):  
Jianwei Cao ◽  
Linyi Gu ◽  
Feng Wang ◽  
Minxiu Qiu
Keyword(s):  
Flow Rate ◽  
Dynamic Characteristics ◽  
Power Supply ◽  
Power Loss ◽  
High Speed ◽  
Hydraulic Pressure ◽  
Hydraulic Systems ◽  
Hydraulic Pump ◽  
Hydraulic Power ◽  
Supply Pressure

Switchmode hydraulic power supply is a new kind of energy-saving pressure converting system, which is originally proposed by the authors. It is mainly applied in multiple-actuator hydraulic systems, and installed between hydraulic pump and actuators (one switchmode hydraulic power supply for one actuator). It can provide pressure or flow rate that is adapted to the consumption of each actuator in the system by boosting or bucking the pressure, with low power loss, and conveniently, through high-speed switch valves, just like a hydraulic pressure transformer. There are two basic types of switchmode hydraulic power supply: pressure boost and pressure buck. Their structures and working principles are introduced. The dynamic characteristics of two typical types of switchmode hydraulic power supply, the pressure boost type and the pressure buck type, were analyzed through simulations and experiments. The performances were evaluated, and improvements on the efficiency of switchmode hydraulic power supply were proposed.

Research on Electro-Hydraulic Control of Propellers of the Underwater Vehicles With Switch-Mode Hydraulic Power Supply

2006 ◽  
Author(s):  
Jianwei Cao ◽  
Linyi Gu ◽  
Feng Wang ◽  
Ying Chen
Keyword(s):  
Control System ◽  
Power Supply ◽  
High Speed ◽  
Weight Ratio ◽  
Pulse Frequency ◽  
Hydraulic Pressure ◽  
Hydraulic Control ◽  
Pulse Frequency Modulation ◽  
Hydraulic Power ◽  
Switch Mode

Switch-mode hydraulic power supply is a hydraulic pressure converting unit made of some distributed hydraulic components, which can boost or buck hydraulic pressure continuously with low power loss (about 20%)and continuous flow-rate. There are two types of switch-mode hydraulic power supply, pressure boost and pressure buck. (see "Switch-mode Hydraulic Power Supply Theory", 2005 ASME, IMECE-FPST No.79019)[1]. This paper introduces a new propeller driving system using the motor of the switch-mode hydraulic power supply for the underwater vehicle. And PFM (Pulse Frequency Modulation) control of high-speed switch-valves is applied to adjust the rotation speed of the propeller. The system has advantages over the widely used servo-valve valve-control system and pump-control system on the energy-weight ratio, anti-contamination performance and energy-saving capacity.

Development of Test System for Subsea Tree Equipment

2013 ◽  
Vol 440 ◽  
pp. 222-227
Author(s):  
Bao Ping Cai ◽  
Yong Hong Liu ◽  
Yan Ting Zhang ◽  
Jiang Tao Ma ◽  
Yun Wei Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Test System ◽  
Acceptance Testing ◽  
Hydraulic Pressure ◽  
Hydraulic Pump ◽  
Test Procedures ◽  
Hydraulic Power ◽  
Hydraulic Unit ◽  
Pressure Cycling ◽  
Function Testing

A test system for subsea tree equipment is developed for tree function testing after repair. The test system mainly consists of hydraulic unit and electric unit. The hydraulic unit is developed by revamping an old hydraulic power unit, which consist of six components, including reservoir, flush/fill pump circuit, high pressure hydraulic pump circuits, accumulator group, hydraulic supply circuits and fluid return circuit. The electric unit for subsea tree is developed by using NI Compact DAQ system, In order to control the hydraulic unit and acquire the pressure signals easily. The test procedures for flowloops, valve, and hydrostatic hydraulic pressure cycling are proposed based on the factory acceptance testing of subsea tree. A test for a repaired subsea tree is performed by using the developed test system. The results show that the repaired subsea tree is good enough after repair, and verify that the developed test system works well.

High Speed Induced Flow Reciprocating Pumps

1972 ◽  
Vol 186 (1) ◽  
pp. 785-791
Author(s):  
R. L. Creedon ◽  
J. Lobo-Guerrero ◽  
P. R. Selwood ◽  
J. D. Burton
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
Performance Data ◽  
Analogue Computer ◽  
Pump Frequency ◽  
Discharge Line ◽  
New Type ◽  
Induced Flow ◽  
Hydraulic Accumulator ◽  
Work Done

Reciprocating pumps have been used for many years in conjunction with an air vessel or hydraulic accumulator placed between pump and discharge line, in order to control maximum cylinder pressures and to reduce the work done in overcoming friction. The air vessel and the discharge line are, in fact, capacitive and inductive components which together have some natural frequency generally different from the pump frequency. In this paper, it is shown that by matching the natural frequency of the discharge impedance to the pump frequency it is possible to obtain volumetric efficiencies of 200 per cent or more. This ‘induced flow principle’ was incorporated in a small high speed pump developed specifically to overcome the relative bulk and cost of conventional diaphragm pumps. Performance data for the new type of pump are compared with theoretical analogue computer solutions, and it appears that the induced flow principle may have a wider range of application than originally anticipated.

Fault Diagnosis Method for Automotive Panel Processing Equipment Hydraulic System Based on Rough Sets - Neural Networks

2012 ◽  
Vol 522 ◽  
pp. 546-551
Author(s):  
Jiang Han ◽  
Hai Jin Huang ◽  
Lian Xia ◽  
Hua Zhai
Keyword(s):  
Neural Network ◽  
Fault Diagnosis ◽  
Rough Set ◽  
Deep Drawing ◽  
Rough Sets ◽  
Hydraulic System ◽  
High Speed ◽  
Hydraulic Press ◽  
Mechanical Equipment ◽  
Rough Sets Theory

The application, which the intelligence is used in the fault diagnosis, is the main direction of research currently, especially in the fault diagnosis of large mechanical equipment. In order to improve hydraulic system failure diagnosis of high-speed deep drawing hydraulic press, reduce the efficiency and accuracy of difficulty diagnostic staff. By using rough sets theory combining neural network and the method of large NC hydraulic press, hydraulic system fault diagnosis of diagnosis. This paper established based on rough set - neural network fault diagnosis model, and the following hydraulic cushion hydraulic system as an example, the diagnosis in establishing the fault table based on the rough set theory to fault table attribute reduction and generating rules, will rule input to the BP neural network was trained learning. Get in neural network after the test data repository and simulation. Test results show that the method for the diagnosis of high-speed deep drawing hydraulic press hydraulic system fault is effective.

scholarly journals PERHITUNGAN SISTEM HIDROLIK UNTUK PENGGERAK PISAU PADA MESIN PENGHAPUS MARKA JALAN

2020 ◽  
Vol 5 (2) ◽  
pp. 122
Author(s):  
Nanang Ali Sutisna ◽  
Muhammad Munajad
Keyword(s):  
Hydraulic System ◽  
Hydraulic Motor ◽  
Hydraulic Pump ◽  
Hydraulic Power ◽  
The Road ◽  
Overload Protection ◽  
Long Time ◽  
Road Marking ◽  
Grinding System ◽  
Test Result

<p>One of very important and vital tool in road marking is road mark erasing machines. In general, the machine used to repair road markings is a road marking erasing machine that is pushed manually. However, this machine has a disadvantage that requires a long time in the process of erasing the road marking, so making it less efficient. Therefore, the truck road mark erasing machine is one of the options to replace the erasing machine that is pushed manually. The machine uses a grinding system with a vertical blade eraser position and hydraulic power to drive the blades as it is able to withstand shock loads and thrust upwards due to the removal process, having overload protection, and the size of components are not large. The study started with doing observation to the existing manual erasing machine, then determining the required blades and calculating as well as selecting the required components of the hydraulic system.  Based on the calculation, the blade specification was obtained and selected, i.e <em>surface milling cutter</em> of type WFX12200R from Sumitomo Electric Hardmetal Corporation having rotation speed 750 rpm, hydraulic motor from Danfoss of type OMR-80 having torque 136 Nm dan displacement 80.3 cc/rev., and using hydraulic pump from Parker of type 0210 having displacement 21 cc/rev. From the test result in the field, this machine is three times faster than the manually pushed machine, less number of the blade used, and the engine as a resource on the machine is more durable. <strong></strong></p>

Research on the Principle and Characteristic of Compound Switch-Mode Hydraulic Power Supply

2006 ◽  
Author(s):  
Jianwei Cao ◽  
Linyi Gu ◽  
Feng Wang ◽  
Ying Chen
Keyword(s):  
Flow Rate ◽  
Power Supply ◽  
High Speed ◽  
Low Pressure ◽  
Power Supplies ◽  
Duty Ratio ◽  
Hydraulic Pressure ◽  
Hydraulic Power ◽  
Load Pressure ◽  
Switch Mode

Switch-mode hydraulic power supply is a hydraulic pressure converting unit made of some distributed hydraulic components, which can boost or buck hydraulic pressure steplessly, with low power loss (about 20%) and continuous flow-rate[1][2]. There are two types of switch-mode hydraulic power supply. One is pressure boost type and the other is pressure buck type. For the pressure boost power supply, changing of the pressure is realized through instantaneous braking of the large inertia load in the hydraulic inductor. For the buck power supply, changing of the pressure is realized through pulse flow-rate and low-pressure hydraulic complement (see "Switch-mode Hydraulic Power Supply Theory", 2005 ASME, IMECE-FPST No.79019)[2]. Because the output pressure is determined by the load, pressure buck is still requisite in pressure boost power supply. At the same time the system is unstable and with low efficiency. To deal with the problem that the pressure boost type switch mode hydraulic power supply is unfit for the low pressure load, the principle and the structure of a compounded switch-mode hydraulic power supply are proposed in this paper. In the compounded switch-mode hydraulic power supply, a pressure buck power supply is cascaded after a pressure boost power supply. At the same time, the output hydraulic capacitor of the pressure buck power supply and the input hydraulic capacitor of the pressure boost power supply are removed, which leads to the direct connection of the hydraulic inductors of the two power supplies Because of the same working principles of the two power supplies, one of the hydraulic inductors can be removed. Pressure boost and pressure buck are realized through the synchronically control of the two high - speed switch valves using PWM signal. No matter the outer load determined pressure is higher or lower than the pump pressure, compounded switch-mode hydraulic power supply can provide the proper power (not flow rate) matching actuators' consumption through regulating the duty ratio of the control signal. Therefore the optimal energy -saving is realized. Experimental research shows that the compounded switch-mode hydraulic power supply can realize a continuous bucking and boosting pressure with different duty ratio and the whole efficiency is at least 80%.

Selection of the optimal hydraulic drive for the press

2021 ◽  
pp. 50-60
Author(s):  
A.A. Antsifirov ◽  
V.A. Krivoshein
Keyword(s):  
Technological Process ◽  
Electric Motor ◽  
Software Package ◽  
Hydraulic Drive ◽  
Hydraulic Press ◽  
Topological Model ◽  
Electric Motors ◽  
Engine Operation ◽  
The Press ◽  
Selection Of

The research presented in the article is devoted to the selection of the electric motor of the hydraulic press drive with a nominal force of 5MN. The article presents the main characteristics and the description of the press operation using the means of mechanization of the technological process of pressure treatment. Using the Deform-3D software package, the process of stamping the crosspiece of the ZIL-130 cardan shaft was simulated. Based on the presented hydraulic scheme of the press, its topological model was formed in the PA-9 software package. The deformation force obtained in the course of modeling the technological process of stamping was used in the topological model of the press. Using a tabular cyclogram, the sequence of actuation of the end switches and hydraulic distributors during the stamping process is shown. In the article, two variants of engine operation were analyzed. Based on the results of the conducted research, it is necessary to focus on the second version of the 55 kW engine, the operation of which will provide the required characteristics of the hydraulic drive of the press, which in turn will allow for technological stamping operations. The simulation tools allow providing estimated information when selecting the necessary tools to ensure the optimal characteristics of hydraulic press drives. The article considered the variation of electric motors that differ from each other in nominal characteristics, with constant characteristics of the pump. For more accurate estimates of energy savings during the operation of the hydraulic drive, it is necessary to vary the characteristics of the pump in the simulation, and the best option is to form an experiment planning matrix when combining the characteristics of the electric motor and the hydraulic pump. This approach ultimately allows forming a function for which one can select a hydraulic drive from existing brands of electric motors and hydraulic pumps for presses of the corresponding range of nominal force.

IMPROVEMENT OF THE PROCESS OF OPERATION OF THE GUIDE MOVING CROSSBARS OF HYDRAULIC PRESSES

2020 ◽  
Author(s):  
K.O. Kobzev ◽  
◽  
S.A. Vyalov ◽  
E.S. Bozhko ◽  
I.A. Zolotuhina ◽  
...  
Keyword(s):  
Service Life ◽  
Hydraulic Press ◽  
Operating Conditions ◽  
The Press ◽  
Technical Solutions

This article deals with the problem of operating conditions of guide moving crossbars of hydraulic presses. Based on the study of hydraulic press operation processes, the need to develop and implement measures to ensure reliable and trouble-free operation of the press was identified. The conclusion justifies the idea that if these technical solutions are implemented, the service life of hydraulic presses will increase

Calculation of a closed hydraulic volumetric system

2021 ◽  
pp. 27-30
Author(s):  
Keyword(s):  
Power Plant ◽  
Wind Power ◽  
Hydraulic System ◽  
Working Fluid ◽  
Wind Power Plant ◽  
Hydraulic Systems ◽  
Hydraulic Motor ◽  
Hydraulic Pump ◽  
Oil Pump ◽  
Selection Of

An algorithm is proposed for calculating a closed volumetric hydraulic pump-hydraulic motor system using the example of the hydraulic system of a wind power plant, based on the calculation of the hydraulic systems of mobile machines. The main characteristics of the system components, the selection of initial data for the calculation, working fluid and diameters of hydraulic lines are analyzed. Keywords: hydraulic system, energy, fluid, oil, pump, motor, renewable energy source, wind power plant, machine. [email protected]

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