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This paper compares the turning and stationary groove configurations of oil lubricated journal bearings used in hard disk drive (HDD) spindle motors under transient contact conditions, such as at startup and shutdown. With rapidly expanding applications for HDDs, spindle motors are required to have lower friction and wear while driving more disks, and be downsized at the same time. It has been known for some time that the turning groove bearing outperforms the stationary groove bearing with regard to friction torque in steady-state operations. However, the friction and wear of the two configurations under the transient contact conditions are still not well understood. To clarify this, we used a model previously proposed and validated experimentally to determine the motion of the turning member in the bearing by simultaneously solving the nonlinear differential equations of motion, the pressure-compliance relationship of elastic-plastic roughness contact, and the average flow Reynolds equation. The different characteristics of the turning and stationary groove configurations are then discussed for both herringbone groove and multi-taper bearings. Index Terms--Contact, friction, HDD, hydrodynamic lubrication, spindle motor, wear.

The objective of this study is to investigate a remote laboratory on electric motors using high-speed networks between Japan and the United States. The client, situated at Stanford University, Stanford, CA, accessed the remote laboratory system set up in Japan. Through this client, the remotely located user operated the motors and conducted experiments. The remote laboratory was conducted over a high-quality digital video conference system, making it possible for both sides to communicate smoothly with each other and for the remote user to observe close-up details of the laboratory, including the motor's fine movements. Using a network bandwidth of 15 Mb/s, the authors were able to demonstrate the validity of the remote laboratory experiment. Index Terms--Digital video, Internet, mechatronics, practice, real-time, reality, remote laboratory.

A simulation program for the claw-pole permanent-magnet (PM) stepping motor was developed for use in a college classroom. Based on circuit equations and equations of motion, it aims to impart to the student the ability to develop insight into the PM stepping motor, which operates on simple principles but displays sophisticated characteristics when electronically driven. The step-position error caused by cogging torque and assembly error, and measures to reduce such errors, are discussed. It is concluded that this software can provide a useful tool for practical mechatronics design. Index Terms--Modeling, programming, real-world design, simulation, stepping motor.

The objective of this study is to investigate remote-learning methods in the context of mechatronics education, and in particular, for the study of brushless dc motors, which are extensively employed in robots, information devices, home appliances and other areas. While hypermedia-based courseware and computer-assisted instruction are widely used in conventional desk-type learning, very few examples exist of remote learning that involve experiments. The authors therefore developed a prototype client-server system for remotely conducting experiments on brushless dc motors, including web-based courseware and other software. The server computer is connected to the motor laboratory, and the visual image and sounds of the experiment are transmitted to the client computer in real time. The remotely located user can operate the motors and conduct experiments through the client computer. Through demonstrations to a class, the authors conclude that the remote lab combined with a simulation of the motor's dynamic behavior can be a quite effective teaching aid for the study of small motors. Index Terms--Brushless DC motor, distance learning, mechatronics, on-line laboratory.

The need for a mechatronics simulation software is pointed out with special reference to engineering education, after which we present a convenient approach. Our basic algorithm computes the electro-mechanical behavior of electric motors combined with mechanical components like inertial/frictional/torsional loads, including such transmission elements as gears or lead screw/nuts. The simplicity and utility of our mathematical treatment are discussed in terms of its educational merits. The major theory is developed using a brash-type permanent dc motor, but brushless dc and stepping motors are discussed as well. We present three sample software. One is a simple program which demonstrates the computational principles for the electric current in an LRC circuit or the velocity of a suspended mass. The other two simulate the dynamic behavior of a slide table powered by a dc motor via gears and a lead screw. One is written in Microsoft Visual Basic code reflecting the physical meaning of mechanical components and the other is a Visual C++ version using the class library concept. The merits and demerits of these two approaches are discussed from the vantage point of undergraduate education and the retraining of technical instructors and working engineers. Index Terms--3-D animation, electromechanical, mechatronics, simulation, small electric motors.

Continuously increasing areal recording density requires systematic optimal analysis of hard disk drive (HDD) spindle motors (SPMs) down to submicro/nanometer-scale level. Conventional SPM investigations have usually consisted of discrete analyses under separate disciplines, and thus are unable to achieve such systematical optimum among the motor's principal components. In order to bridge the relational gap existing between the principal components, an integrated system modeling and analysis that can quantitatively analyze the influences of individual components such as the control algorithm, drive circuit, motor, rotor, and bearing on overall characteristics is developed for HDD spindle motors. The influences of pulse-width modulation modes and driving circuit parameters on startup characteristics are investigated to demonstrate the importance of the proposed method. [ABSTRACT FROM AUTHOR]

This paper compares the turning and stationary groove configurations of oil lubricated journal bearings used in hard disk drive (HDD) spindle motors under transient contact conditions, such as at startup and shutdown. With rapidly expanding applications for HDDs, spindle motors are required to have lower friction and wear while driving more disks, and be downsized at the same time. It has been known for some time that the turning groove bearing outperforms the stationary groove bearing with regard to friction torque in steady-state operations. However, the friction and wear of the two configurations under the transient contact conditions are still not well understood. To clarify this, we used a model previously proposed and validated experimentally to determine the motion of the turning member in the bearing by simultaneously solving the nonlinear differential equations of motion, the pressure-compliance relationship of elastic-plastic roughness contact, and the average flow Reynolds equation. The different characteristics of the turning and stationary groove configurations are then discussed for both herringbone groove and multi-taper bearings. [ABSTRACT FROM AUTHOR]

Discusses the development of a multimedia training material for use at the high-level public vocational training center, Chubu Polytechnic Center, Japan, run by the Employment Promotion Corporation. Reason for development of instructional material; What material allows for; Difference with this system; Response of those attending seminar using this material; Background information on center.

Describes an electrical machinery laboratory named MECHATRO LAB 2PLUS. What the machinery is designed to do; Historical design of the machinery; Advantages of the machinery.