A Method of Reducing Windage Power Loss in a Laser Scanner Mirror by Using the Pumping Effect of Herringbone-Grooved Gas Journal Bearings

1999 ◽  
Vol 121 (3) ◽  
pp. 506-509 ◽  
Author(s):  
S. Yoshimoto ◽  
A. Takahashi
Keyword(s):  
Power Consumption ◽  
Laser Beam ◽  
Power Loss ◽  
High Speed ◽  
Journal Bearing ◽  
Laser Scanner ◽  
Journal Bearings ◽  
Vacuum Pump ◽  
Low Power Consumption ◽  
Reduced Power Consumption

This paper proposes a newly developed laser scanner motor with low power consumption, operating at a high speed of rotation. The principle of the scanner motor is that of a herringbone-grooved journal bearing functioning as a viscous vacuum pump. The windage power loss of a polygon mirror can be reduced because the air inside the housing is pumped out by herringbone-grooved viscous vacuum pumps. The performance of the proposed laser scanner motor was measured under various conditions. It was subsequently found that the proposed scanner motor of a laser beam had much reduced power consumption and higher scanning accuracy than the conventional scanner motor in which the rotor is rotated in the air.

Power Loss of Tilting 5-Pad Journal Bearing Operating With Turbulent Oil Film

2005 ◽  
Author(s):  
S. Strzelecki
Keyword(s):  
Power Loss ◽  
High Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Heavy Duty ◽  
Safe Operation ◽  
Oil Film ◽  
Full Knowledge

Journal bearings of high speed turbocompressors, compressors and heavy duty high speed turbine gearboxes operate at journal peripheral speeds like 150 m/s. The flow of lubricant in such bearings is not laminar but super laminar or turbulent. It results in the increase in power loss and in the decrease of the bearing stability. The ground for the safe operation of high speed journal bearings at proper oil film temperature and with less power loss is the full knowledge of bearing performances at the turbulent oil film.

Pumping Characteristics of a Herringbone-Grooved Journal Bearing Functioning as a Viscous Vacuum Pump

1999 ◽  
Vol 122 (1) ◽  
pp. 131-136 ◽  
Author(s):  
S. Yoshimoto ◽  
Y. Ito ◽  
A. Takahashi
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Slip Flow ◽  
Laser Scanner ◽  
Vacuum Pump ◽  
Chamber Pressure ◽  
Design Parameters ◽  
Theoretical Predictions ◽  
Flow Effects ◽  
Good Agreement

A laser scanner motor with low power and high speed has been developed. This scanner motor uses a herringbone-grooved journal bearing which functions as a viscous vacuum pump. The windage power loss of a polygon mirror is reduced, since the air inside the pump housing is pumped out by herringbone-grooved viscous vacuum action. In this paper, the theoretical pumping characteristic of this bearing is investigated, using the narrow-groove theory and accounting for first-order slip flow. The effects of various design parameters on the pumping characteristics are discussed. Optimum geometric design parameters were found to obtain the minimum inner chamber pressure of the housing. The theoretical predictions considering slip flow effects are in good agreement with experimental measurements. [S0742-4787(00)01801-4]

scholarly journals Ultracompact and low-power-consumption silicon thermo-optic switch for high-speed data

Nanophotonics ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 937-945
Author(s):  
Ruihuan Zhang ◽  
Yu He ◽  
Yong Zhang ◽  
Shaohua An ◽  
Qingming Zhu ◽  
...  
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
High Speed ◽  
High Performance ◽  
Pulse Amplitude ◽  
Telecommunication Networks ◽  
Low Power Consumption ◽  
Power Efficient ◽  
High Speed Data ◽  
On Chip

AbstractUltracompact and low-power-consumption optical switches are desired for high-performance telecommunication networks and data centers. Here, we demonstrate an on-chip power-efficient 2 × 2 thermo-optic switch unit by using a suspended photonic crystal nanobeam structure. A submilliwatt switching power of 0.15 mW is obtained with a tuning efficiency of 7.71 nm/mW in a compact footprint of 60 μm × 16 μm. The bandwidth of the switch is properly designed for a four-level pulse amplitude modulation signal with a 124 Gb/s raw data rate. To the best of our knowledge, the proposed switch is the most power-efficient resonator-based thermo-optic switch unit with the highest tuning efficiency and data ever reported.

A method of reducing the windage power loss in a laser scanner motor using spiral-groove aerodynamic thrust bearings functioning as a viscous vacuum pump

2006 ◽  
Vol 13 (8-10) ◽  
pp. 1123-1130 ◽  
Author(s):  
Shigeka Yoshimoto ◽  
Masaaki Miyatake ◽  
Tomoatsu Iwasa ◽  
Akiyoshi Takahashi
Keyword(s):  
Power Loss ◽  
Laser Scanner ◽  
Vacuum Pump ◽  
Spiral Groove ◽  
Thrust Bearings

scholarly journals A high-speed hybrid Full Adder with low power consumption

2012 ◽  
Vol 9 (24) ◽  
pp. 1900-1905
Author(s):  
Kamran Delfan Hemmati ◽  
Mojtaba Behzad Fallahpour ◽  
Abbas Golmakani ◽  
Kamyar Delfan Hemmati
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
High Speed ◽  
Full Adder ◽  
Low Power Consumption

Influence of geometric parameters and operating conditions on the thermohydrodynamic behaviour of plain journal bearings

2000 ◽  
Vol 214 (5) ◽  
pp. 445-457 ◽  
Author(s):  
I Pierre ◽  
M Fillon
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Thermal Dissipation ◽  
Radial Clearance ◽  
Geometric Factors ◽  
Essential Components ◽  
Mass Flowrate

Hydrodynamic journal bearings are essential components of high-speed machinery. In severe operating conditions, the thermal dissipation is not a negligible phenomenon. Therefore, a three-dimensional thermohydrodynamic (THD) analysis has been developed that includes lubricant rupture and re-formation phenomena by conserving the mass flowrate. Then, the predictions obtained with the proposed numerical model are validated by comparison with the measurements reported in the literature. The effects of various geometric factors (length, diameter and radial clearance) and operating conditions (rotational speed, applied load and lubricant) on the journal bearing behaviour are analysed and discussed in order to inform bearing designers. Thus, it can be predicted that the bearing performance obtained highly depends on operating conditions and geometric configuration.

Incorporation of THD Boundary Conditions for the Efficient Evaluation of Journal Bearing Performance

2007 ◽  
Author(s):  
P. S. Keogh ◽  
M. M. Khonsari
Keyword(s):  
Boundary Conditions ◽  
High Speed ◽  
Current Practice ◽  
Journal Bearing ◽  
Coefficient Matrix ◽  
Journal Bearings ◽  
Heat Fluxes ◽  
Solid Component ◽  
Influence Coefficient ◽  
Thermal Boundary Conditions

The evaluation of the thermohydrodynamic (THD) performance of journal bearings continues to be an important issue. This is particularly so for high speed or heavily loaded bearing designs. This paper focuses attention on the thermal boundary conditions at the lubricant-bearing interface. The solid component conduction problem is solved in advance of the main THD analysis. Boundary conditions are then imposed on the lubricant THD analysis through use of an appropriate influence coefficient matrix that incorporates the solid component conduction problem. This avoids the current practice of solving the lubricant and solid component problems separately in an iterative loop to achieve continuous temperatures and heat fluxes at the interface. Instead, only the lubricant problem needs to be solved using the boundary conditions imposed by the influence coefficient matrix.

Effect of Journal Misalignment on the Oil Film Pressure and Temperature Distribution of 3-Lobe Offset Journal Bearing

2005 ◽  
Author(s):  
S. Strzelecki ◽  
Z. Towarek
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Good Stability ◽  
Rotating Machines ◽  
Film Pressure ◽  
Bearing Design ◽  
Journal Misalignment ◽  
Oil Film Pressure

The design of turbines and compressors operating at the high rotational speeds applies the 3-lobe journal bearings. In many cases the classic 3-lobe journal bearings supporting the rotors, are showing the problem of rotor stability. This problem can be avoided by the application of 3-lobe Offset bearings. This type of bearing fulfils the conditions of reliable bearing design and good stability in the case of high speed rotating machines.

scholarly journals Integration of highly anisotropic multiferroic BaTiO3–Fe nanocomposite thin films on Si towards device applications

2020 ◽  
Vol 2 (9) ◽  
pp. 4172-4178
Author(s):  
Matias Kalaswad ◽  
Bruce Zhang ◽  
Xuejing Wang ◽  
Han Wang ◽  
Xingyao Gao ◽  
...  
Keyword(s):  
Thin Films ◽  
Power Consumption ◽  
Low Power ◽  
High Speed ◽  
Low Cost ◽  
Low Power Consumption ◽  
Silicon Substrates ◽  
Critical Step ◽  
Nanocomposite Thin Films ◽  
Device Applications

Integration of highly anisotropic multiferroic thin films on silicon substrates is a critical step towards low-cost devices, especially high-speed and low-power consumption memories.

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