Study on Precision Machine Table Equipped with Constant-Flow Hydrostatic Water Bearings

2009 ◽  
Vol 76-78 ◽  
pp. 664-669
Author(s):  
Akinori Yui ◽  
Shigeki Okuyama ◽  
Takayuki Kitajima ◽  
Etsuo Fujita ◽  
Alexander Henry Slocum ◽  
...  
Keyword(s):  
Environmental Pollution ◽  
Electric Power ◽  
Flow Rate ◽  
Machine Tools ◽  
Iron Core ◽  
Constant Flow ◽  
Static Stiffness ◽  
Environmental Friendly ◽  
Gear Pumps ◽  
Bearing System

In order to realize environmental-friendly machine tools, a linear-motor-driven table supported by constant-flow hydrostatic water bearings is developed. The table system is free from environmental pollution because the system needs no oil. For simplicity, a single-sided bearing system is chosen for the table-slide. To obtain a high sustaining force, preload is applied to the bearings using the attractive force of an iron core linear-motor’s magnets. The preload is effective in both the vertical and horizontal directions by inclined motor magnets. Miniature gear-pumps supply flow to the bearings without pump pulsation, and the bearings consume very small amounts of water and electric power. The measured table sustaining force was 3.0kN and static stiffness was 0.3kN/m under a flow rate Q=0.92mL/s per bearing and ideal bearing clearance h=16m.

Experimental and numerical analysis of a self-circulating oil bearing system for gear pumps

2018 ◽  
Vol 70 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Mo Jintao ◽  
Gu Chaohua ◽  
Pan Xiaohong ◽  
Zheng Shuiying ◽  
Ying Guangyao
Keyword(s):  
Flow Rate ◽  
Pressure Difference ◽  
The Self ◽  
Gear Pump ◽  
Moderate Pressure ◽  
Test Rig ◽  
Content Type ◽  
Oil Flow ◽  
Gear Pumps ◽  
Bearing System

Purpose For moderate pressure and high pressure gear pumps, the temperature failure problem of bearings is now of considerable concern because of their heavy loads. However, the compact structure and the efficiency consideration make it extremely difficult to improve the bearing cooling. A self-circulating oil bearing system is developed for gear pumps with self-lubricating bearings to solve this problem. The oil is aspirated in from the low pressure chamber of the gear pump and discharged to the same chamber by using the pressure difference in the journal bearing, thus achieving the self-circulation. Design/methodology/approach An experiment test rig has been built for the feasibility study. The oil flow rate under different speeds has been recorded. Furthermore, the temperatures of the bearings with or without the oil circulation have been compared. Additionally, the oil flow in the test rig has been simulated using computational fluid dynamics codes. Findings The experimental and numerical results agree well. The experimental results indicate that the oil flow rate increases approximately linearly with the speed and the bearing temperature can be lowered successfully. The calculation results indicate that the bearing load capacity is nearly the same. Both the experimental and numerical studies establish that the self-circulating oil bearing system works successfully. Originality value As far as the authors know, it is the first time to find that the self-circulation can be built using the pressure difference in the bearing oil film, and this principle can be applied in the cooling and lubrication of the gear pumps to solve the temperature failure problem.

Pumpless Fuel Supply Using Pressurized Fuel Regulated by Autonomous Flow-Rate Regulation Valves

2012 ◽  
Vol 9 (3) ◽  
Author(s):  
Il Doh ◽  
Young-Ho Cho
Keyword(s):  
Fuel Cells ◽  
Flow Rate ◽  
Electrical Power ◽  
Initial Pressure ◽  
Flow Regulation ◽  
Present System ◽  
Constant Flow ◽  
Constant Flow Rate ◽  
Fuel Supply ◽  
Fuel Flow

A pumpless fuel supply using pressurized fuel with autonomous flow regulation valves is presented. Since micropumps and their control circuitry consume a portion of the electrical power generated in fuel cells, fuel supply without micropumps makes it possible to provide more efficient and inexpensive fuel cells than conventional ones. The flow regulation valves in the present system maintain the constant fuel flow rate from the pressurized fuel chamber even though the fuel pressure decreases. They autonomously adjust fluidic resistance of the channel according to fuel pressure so as to maintain constant flow rate. Compared to previous pumpless fuel supply methods, the present method offers more uniform fuel flow without any fluctuation using a simple structure. The prototypes were fabricated by a polymer micromolding process. In the experimental study using the pressurized deionized water, prototypes with pressure regulation valves showed constant flow rate of 5.38 ± 0.52 μl/s over 80 min and 5.89 ± 0.62 μl/s over 134 min, for the initial pressure in the fuel chamber of 50 and 100 kPa, respectively, while the other prototypes having the same fluidic geometry without flow regulation valves showed higher and gradually decreasing flow rate. The present pumpless fuel supply method providing constant flow rate with autonomous valve operation will be beneficial for the development of next-generation fuel cells.

Optimization of a Raw Water Source Heat Pump for a Vertical Water Treatment Building

2015 ◽  
Vol 23 (01) ◽  
pp. 1550002
Author(s):  
Sunhee Oh ◽  
Yong Cho ◽  
Rin Yun
Keyword(s):  
Power Consumption ◽  
Electric Power ◽  
Flow Rate ◽  
Storage Tank ◽  
Water Flow Rate ◽  
Water Source ◽  
Thermal Storage ◽  
Electric Power Consumption ◽  
Air Flow Rate ◽  
Circulating Water

The optimum operation conditions of a raw water source heat pump for a vertical water treatment building were derived by changing operation parameters, such as temperature of thermal storage tank, temperature and inlet air flow rate of the conditioned spaces, and circulating water flow rate between thermal storage tank and air handling unit (AHU) through dynamic simulator of a transient system simulation program (TRNSYS). Minimum electric power consumption was found at temperature of thermal storage tank, which was ranged 18–23°C for cooling season. In heating season, temperature 40–45°C brings the highest coefficient of performance (COP) and temperature range of 30–35°C brings the lowest power consumption. When the temperature of the conditioned spaces was controlled between 27–28°C for cooling season, and 18–20°C for heating season the minimum electric power consumption was obtained. Inlet air flow rate of 1.1 m3/h for the conditioned spaces shows the highest performance of the present system, and effects of circulating water flow rate between thermal storage tank and AHU on minimum electric power consumption of the system were negligible.

Behavior of Thermal Effects and Velocity-Slip on Performance of Externally Pressurized Porous Incompressible Gas Thrust Bearing

1979 ◽  
Vol 46 (2) ◽  
pp. 465-468 ◽  
Author(s):  
V. K. Kapur ◽  
J. S. Yadav
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Effects ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Velocity Slip ◽  
Experimental Results ◽  
Slip Condition ◽  
Static Stiffness

In the present analysis, the interactions of thermal effects and velocity slip on the performance of externally pressurized porous incompressible gas thrust bearing have been studied. Numerical results for load capacity, mass flow rate, and static stiffness have been obtained and their behavior is illustrated in figures. The results for slip as well as no-slip condition have also been compared with the experimental results of Gargiulo and Gilmour [7].

scholarly journals Flow rate control for constant film thickness of hydrostatic bearing system

2018 ◽  
Vol 1074 ◽  
pp. 012008
Author(s):  
Yuan Kang ◽  
Sie-Sing Jhang ◽  
Sheng-Xiang Peng ◽  
Wen-Chou Chen ◽  
Sheng-Yen Hu
Keyword(s):  
Film Thickness ◽  
Flow Rate ◽  
Rate Control ◽  
Hydrostatic Bearing ◽  
Flow Rate Control ◽  
Bearing System

scholarly journals FEA-Analysis of Shaft and Supports Deformations for Huge Precise Lathe. Statics and Resonances

2018 ◽  
Vol 1 (1) ◽  
pp. 341-348
Author(s):  
Stanislau Dounar ◽  
Alexandre Lakimovitch ◽  
Andrei Ausiyevich ◽  
Andrzej Jakubowski
Keyword(s):  
System Simulation ◽  
Static Stiffness ◽  
Load Bearing ◽  
Machining Forces ◽  
Rotor Shaft ◽  
Fea Analysis ◽  
Bearing System

Abstract Load bearing system simulation is provided for a huge lathe to be renovated. Static and modal analyses are done by FEM. Focus was centerline rising, needed for larger rotor shaft machining. Forces between shaft and three supports were applied. Shaft static stiffness is lowered at 1.15 times only for 600 mm centerline rising. Supports have lost its rigidity at 1.42 times. Concrete pouring into bed cavities is recommended for supports flexibility limitation such as tailstock reinforcement. Robustness of bottom resonances is revealed both for rotor shaft (14.5–18.2 Hz) and supports (42.7–55.4 Hz). Centerline rising is allowed on 300 mm at least. It gives possibility to machine extremely large (up to ø2750 mm) shafts.

scholarly journals Research Regarding the Flow Rate and Pressure Variation for the Nozzles Mounted on the Eep-600m Spraying Machine

2011 ◽  
Vol 68 (1) ◽  
Author(s):  
Ioan DROCAS ◽  
Ovidiu MARIAN ◽  
Ovidiu RANTA ◽  
Sorin STANILA ◽  
Mircea MUNTEAN ◽  
...  
Keyword(s):  
Environmental Pollution ◽  
Flow Rate ◽  
Pressure Variation ◽  
Experimental Results ◽  
Nozzle Flow ◽  
Liquid Pressure ◽  
Functional Parameters ◽  
Fair Treatment ◽  
Nozzle Position ◽  
The Way

Reduced environmental pollution and ensuring fair treatment in crops can be achieved through constructive and functional upgrading of spraying machines. The paper studies the variation of the nozzle flow, liquid pressure and uniformity of distribution for the EEP-600M machine. The experimental results have shown changes in the functional parameters of the nozzle (flow and pressure) depending on the nozzle position on the ramp section. The way of connecting the hoses leading the solution to the ramp and the number of nozzles per segment can influence the uniformity of distribution of the solution.

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