Power Consumption and Temperature Considerations in Disk Drives

2002 ◽  
Author(s):  
Erhard Schreck ◽  
Joerg Ferber
Keyword(s):  
Power Consumption ◽  
Detailed Analysis ◽  
Disk Drive ◽  
Spindle Motor ◽  
Current Drive ◽  
Operating Conditions ◽  
Temperature Gradients ◽  
Main Function ◽  
Disk Drives ◽  
Time Constants

This work studies the contributions of various drive components to the overall drive temperature and temperature gradients within a drive. Data is presented from a variety of 3.5 inch disk drives under varying operating conditions. The average drive case temperature is a result of individual contributors like electronics components on the PCB, spindle motor and actuator. Each of these components dissipate power depending on their main function, the drive operation and in some cases depending on the current drive temperature. Due to the large variety of drive designs this work concentrates on the characteristics of different components in terms of individual temperatures and time constants rather than detailed analysis of one specific disk drive.

Acoustic Control of Disk Drives

1995 ◽  
Author(s):  
Raymond Chin ◽  
Donald Wong ◽  
Akihiko Kumano
Keyword(s):  
Broad Band ◽  
Structural Response ◽  
Sound Intensity ◽  
Disk Drive ◽  
Spindle Motor ◽  
Experimental Investigations ◽  
Disk Drives ◽  
Acoustic Frequency ◽  
Acoustic Performance ◽  
Sinusoidal Excitation

Abstract In the present effort, a series of experimental investigations was conducted to ascertain noise generation mechanisms involved in 3.5 inch and 5.25 inch disk drives with the ultimate objective to improve the acoustic performance. The acoustic performance of selected samples was characterized in terms of sound pressure and power in a frequency range of up to 8 KHz. The acoustic and structural response of the disk drive were examined using an impact hammer and sinusoidal excitation at the spindle motor. In addition, motor torque characteristics data was collected. A sound intensity measurement technique was employed for the delineation of the acoustic directionality. Two major contributors were identified through the acoustic characterization measurement: (1) broad band noise and (2) prominent discrete tone (PDT). It was shown that the major feature extant in the disk drive acoustic frequency spectrum can be reconstructed from the data obtained from sinusoidal excitation and acoustic response data. Based on the data collected, a series of modifications were evaluated including changes to the spindle motor design, application of dampers, and introduction of vibration isolators. These modifications yielded an acoustic level reduction of 3 to 5dB. Additionally, the parts, process, and operating condition tolerances were found to have a measurable effect on the acoustic performance of disk drive.

Enhancement of Hard Disk Drive Heat Dissipations With Integrated Cooling Devices

2008 ◽  
Author(s):  
J. P. Yang ◽  
C. P. H. Tan ◽  
E. H. Ong
Keyword(s):  
Power Consumption ◽  
High Performance ◽  
Heat Dissipation ◽  
Hard Disk Drives ◽  
Thermal Characteristics ◽  
Hard Disk ◽  
Disk Drive ◽  
Disk Drives ◽  
Design Engineers ◽  
Operational Life

Thermal management has become a significant issue to be considered whilst designing high performance and high reliable hard disk drives (HDD). This paper proposes a compact ultra-thin cooling device for enhancing heat dissipation of HDD. The miniature device was designed and prototyped to its optimal cooling efficiency according to the thermal characteristics of operating HDD. The experimental results of this newly developed device show that it can offer up to 35% enhancement of heat dissipation with a lower power consumption of 10 mW. Furthermore, the low power consumption device has been fully integrated with the disk drive without modifying the structure of the disk drive. This device provides a key for the design engineers in developing reliable and longer operational life hard disk drives.

Effects of Temperature on Particle Trajectory Inside the Helium-Filled Hard Disk Drive

2016 ◽  
Author(s):  
Yuwen Zhu ◽  
Guoqing Zhang ◽  
Shengnan Shen ◽  
Hui Li ◽  
Yun Yang ◽  
...  
Keyword(s):  
Particle Trajectory ◽  
Hard Disk Drives ◽  
Voice Coil Motor ◽  
Hard Disk ◽  
Disk Drive ◽  
Spindle Motor ◽  
Disk Drives ◽  
Submicron Particle ◽  
Effects Of Temperature ◽  
Al2o3 Particles

The presence of particles, which can intrude into the air bearing, is one of the most common factors in the failure of hard disk drives (HDDs). Previous works investigated the particle trajectory inside air-filled drives without considering the temperature effects on the distribution of particles. Actually, for the submicron particle, particle trajectory and trapping status are affected by the temperature gradient since the thermophoretic force cannot be ignored. In this paper, considering the major heat generation components such as spindle motor and voice coil motor (VCM), the trajectories and trapping status for Al2O3 particles with diameter of 0.3 μm inside a 2.5 inch helium-filled drive are simulated by the commercial computational fluid dynamics solver FLUENT with user-defined functions (UDFs). The trapping criterion for Al2O3 particles are used as the boundary conditions for the different colliding surfaces.

scholarly journals Optimum Design of Oil Lubricated Thrust Bearing for Hard Disk Drive with High Speed Spindle Motor

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Yuta Sunami ◽  
Mohd Danial Ibrahim ◽  
Hiromu Hashimoto
Keyword(s):  
High Speed ◽  
Thrust Bearing ◽  
Dynamic Stiffness ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drive ◽  
Optimization Method ◽  
Spindle Motor ◽  
Disk Drives ◽  
Thrust Bearings

This paper presents the application of optimization method developed by Hashimoto to design oil lubricated thrust bearings for 2.5 inch form factor hard disk drives (HDD). The designing involves optimization of groove geometry and dimensions. Calculations are carried out to maximize the dynamic stiffness of the thrust bearing spindle motor. Static and dynamic characteristics of the modeled thrust bearing are calculated using the divergence formulation method. Results show that, by using the proposed optimization method, dynamic stiffness values can be well improved with the bearing geometries not being fixed to conventional grooves.

Optimized control over modes of hydraulic percussion cutting heads of mining machines

2020 ◽  
pp. 95-104
Author(s):  
Yu. M. Smirnov ◽  
B. M. Kenzhin ◽  
N. S. Smakova ◽  
M. A. Zhurunova
Keyword(s):  
Time Derivative ◽  
Operating Conditions ◽  
Control Action ◽  
Main Function ◽  
Output Data ◽  
Working Cycle ◽  
Control Units ◽  
Action Change ◽  
Function Element ◽  
Service Factors

The main cause of the disagreement between the actual and calculated output data of hydraulic percussion mining machines is the erroneous feed of manipulation signals by the control units. For the maximal fitting of the calculated and actual figures, the continuous method of control action using the third time derivative of the law of motion of the main function element is accepted, namely, the accuracy. The mathematical models of control using displacement, velocity and acceleration are developed. The service factors of mining machines are found. Based on the theory of control and the mathematical logic theory, the logical circuits of formation of manipulation signals in each phase of the working cycle are developed. The main elements are converters, integrators and accumulators ensuring decomposition of elements of the logical circuits and further generation of appropriate control action. It is found that the simplest way is to generate the control action for acceleration of the key function element. For the developed circuits, it is recommended to use general charts of the control action change, implementable for a certain design of hydraulic percussion cutting heads in certain operating conditions.

scholarly journals Evaporator Optimization of Refrigerator Systems Using Quality Analysis

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 555
Author(s):  
Sangkyung Na ◽  
Sanghun Song ◽  
Seunghyuk Lee ◽  
Jehwan Lee ◽  
Hyun Kim ◽  
...  
Keyword(s):  
Power Consumption ◽  
Operating Time ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Quality Analysis ◽  
Lubricating Oil ◽  
Optimal Operating ◽  
Compressor Piston ◽  
Refrigerator Temperature ◽  
Visualization Experiments

In this study, evaporator optimization, via both experimental and simulation methods was conducted. To evaluate the evaporator performance, under the optimal system, the compressor operating time and the effects of oil on the refrigerator system were studied. If the temperature of the refrigerator chamber reaches the setting value, the compressor stops working and it leads to the temperature of the refrigerator chamber slowly increasing, due to the heat transfer to the ambient. When the refrigerator temperature is out of the setting range, the compressor works again, and the refrigerator repeats this process until the end of its life. These on/off period can be controlled through the compressor piston movement. To determine the optimal compressor operating conditions, experiments of monthly power consumption were conducted under various compressor working times and the lowest power consumption conditions was determined when the compressor worked continuously. Lubricating oil, the refrigerator system, using oil, also influenced the system performance. To evaluate the effect of oil, oil eliminated and oil systems were compared based on cooling capacity and power consumption. The cooling capacity of the oil eliminated system was 2.6% higher and the power consumption was 3.6% lower than that of the oil system. After determining the optimal operating conditions of the refrigerator system, visualization experiments and simulations were conducted to decide the optimal evaporator and the conventional evaporator size can be reduced by approximately 2.9%.

Dynamic Analysis of the Optical Disk Drives Equipped with an Automatic Ball Balancer with Consideration of Torsional Motions

2005 ◽  
Vol 72 (6) ◽  
pp. 826-842 ◽  
Author(s):  
Paul C. P. Chao ◽  
Cheng-Kuo Sung ◽  
Chun-Chieh Wang
Keyword(s):  
Multiple Scales ◽  
Spindle Motor ◽  
Optical Disk ◽  
Torsional Stiffness ◽  
Torsional Motion ◽  
Disk Drives ◽  
Scaled Model ◽  
Supporting Plate ◽  
Steady State Solutions ◽  
Balanced Solution

This study is dedicated to evaluate the performance of an automatic ball-type balancer system (ABS) installed in optical disk drives (ODDs) with consideration of the relative torsional motion between the ODD case and the spindle-disk-ABS-turntable system, noting that the turntable is the supporting plate structure for disk, pickup, and spindle motor inside the ODD. To this end, a complete dynamic model of the ABS considering the torsional motion is established with assuming finite torsional stiffness of the damping washers, which provides suspension of the spindle-disk-ABS-turntable system to the ODD case. Considering the benchmark case of a pair of balancing balls in an ABS, the method of multiple scales is then applied to formulate a scaled model for finding all possible steady-state solutions of ball positions and analyzing corresponding stabilities. The results are used to predict the levels of residual vibration, with which the performance of the ABS can then be reevaluated. Numerical simulations are conducted to verify theoretical results. It is deduced from both analytical and numerical results that the spindle speed of an ODD could be operated above both primary translational and secondary torsional resonances in order to guarantee stabilization of the desired balanced solution for a substantial vibration reduction.

Failure analysis of laser-textured surfaces

2000 ◽  
Vol 214 (5) ◽  
pp. 471-483 ◽  
Author(s):  
S Chilamakuri ◽  
X Zhao ◽  
B Bhushan
Keyword(s):  
Plastic Deformation ◽  
Operating Conditions ◽  
Disk Drives ◽  
Critical Number ◽  
Textured Surfaces ◽  
Tribological Behaviour ◽  
Magnetic Disk ◽  
Size And Shape ◽  
Ultrahigh Density ◽  
Theoretical Results

Friction/stiction behaviour of ultrahigh-density magnetic disk drives can be controlled by controlling the size and shape of the laser bumps. Tribological behaviour of laser-textured disk surfaces depends on the size and shape of the laser bumps, bump density and operating conditions. In this study, theoretical and experimental analyses have been carried out on nine different laser-textured disk surfaces. Stiction and friction experiments have been carried out on sombrero, V-type and W-type laser-textured disks and these results are compared with theoretical results. A good correlation is obtained between experimental and theoretical results. The effect of laser bump uniformity on critical number of bumps required to prevent plastic deformation and stiction has also been studied.

scholarly journals Investigation on membrane fouling in ultrafiltration of latex solution

2021 ◽  
Author(s):  
Amira Abdelrasoul
Keyword(s):  
Mathematical Model ◽  
Molecular Weight ◽  
Power Consumption ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Operating Conditions ◽  
Specific Power ◽  
Pore Sizes ◽  
Wide Range ◽  
Different Types

The low-pressure membrane applications are considered to be the most effective and sustainable methods of addressing environmental problems in treating water and wastewater that meets or exceed stringent environmental standards. Nevertheless, membrane fouling is one of the primary operational concerns that is currently hindering a more widespread application of ultrafiltration (UF) with a variety of contaminants. Membrane fouling leads to higher operating costs, higher energy demand, reduced membrane life time, and increased cleaning frequency. As a consequence, an efficient and well-planned UF process is becoming a necessity for consistent and long-term monetary returns. Examining the source and mechanisms of foulant attachment to the membrane’s surface is critical when it comes to the research of membrane fouling and its potential practical implementation. A mathematical model was developed in this study in order to predict the amount of fouling based on an analysis of particle attachments. This model was developed using both homogeneous and heterogeneous membranes, with a uniform and non-uniform pore sizes for the UF of simulated latex effluent with a wide range of particle size distribution. The objective of this mathematical model was to effectively identify and address the common shortcomings of previous fouling models, and to account for the existing chemical attachments in membrane fouling. The mathematical model resulting from this study was capable of accurately predicting the mass of fouling retained by the membrane and the increase in transmembrane pressure (TMP). In addition, predictive models of fouling attachments were derived and now form an extensive set of mathematical models necessary for the prediction of membrane fouling at a given operating condition, as well as, the various membrane surface charges. Polycarbonate and Polysulfone flat membranes, with pore sizes of 0.05 μm and a molecular weight cut off of 60,000 respectively, were used in the experimental designs under a constant feed flow rate and a cross-flow mode in UF of the simulated latex paint effluent. The TMP estimated from the model agreed with the experimentally measured values at different operating conditions, mostly within 5.0 - 8.0 % error, and up to 13.0% error for the uniform, and non-uniform pore size membranes, respectively. Furthermore, different types of membranes with a variety of molecular weight cut-off (MWCO) values were tested so as to evaluate the accuracy of the models for a generalized application. In addition , a power consumption model, incorporating fouling attachment as well as chemical and physical factors in membrane fouling, was developed in order to ensure accurate prediction and scale-up. Innovative remediation techniques were likewise developed and applied in order to minimize membrane fouling, enhance the membrane performance, and save energy. Fouling remediation methodologies included the pre-treating of the latex effluent, so as to limit its fouling propensity by using different types of surfactants as cationic and anionic, in addition to the pH change. The antifouling properties of the membranes were improved through the implementation of the membrane pH treatment and anionic surfactant treatment. Increasing the ionic strength of latex effluent or enhancing the membrane surface hydrophilicity facilitated a significant increase in the cumulative permeate flux, a substantial decrease in the total mass of fouling, and a noticeable decrease in the specific power consumption.

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