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This paper introduces the basic fundamentals of proportional-integral-derivative (PID) control theory and the characteristics of each of the PID control loops.
The obsolescence of materials and processes in the manufacture of traditional DC brush gearmotors has necessitated the development of an upgraded DC brush gearmotor.
The primary driver of an airport baggage handling queue conveyor must
be able to operate under increasingly demanding operating conditions, including frequent starting and stopping. The selection of the primary driver of the queue conveyor is dependent on multiple criteria, including dimensional requirements and durability characteristics.
American Bearing Manufacturers Association (ABMA) Standard 9 and ISO 281 give equations for calculating
the basic dynamic radial load rating for ball bearings. These equations are based on a number of assumptions, many
of which are not valid for thin-section bearings. (Thin-section bearings are described in ABMA standard 26.2.)
Nevertheless, many thin-section bearing catalogs report load ratings based on these equations. Kaydon has developed a new method for calculating the dynamic radial load rating for thin-section ball bearings. The new method uses the contact stress and the number of stress-cycles-per-revolution to calculate the capacity. The new numbers are based on five years of actual test results. These equations can also be used to calculate the dynamic radial load rating for four-point contact ball bearings, which are not covered in ABMA standard 9 or ISO 281.
During the qualification campaign of the NIRSpec (near-infrared spectrometer) instrument mechanism, the actuator could not achieve the expected lifetime that had been extended during the development phase. The initial design could not be adapted to the requested number of revolutions during that phase. Consequently the actuator needed to be modified so that the function of the mechanism would not be
endangered or, by extension, the overall function of the NIRSpec instrument. The modification included a
change of the overall actuator design—internal dimensions, tolerances, materials, lubrication and assembly
process—while keeping the interface to the mechanism, mass and function.
One of the driving forces behind the industrial revolution was the invention—more than a century ago—of the electric motor. Its widespread use for all kinds of mechanical motion has made life simpler and has ultimately aided the advancement of humankind.
And the advent of the inverter that facilitated speed and torque control of AC motors has propelled the use of electric motors to new realms that were inconceivable just a mere 30 years ago. Advances in power semiconductors—along with digital controls—have enabled realization of motor drives that are robust and can control position and speed to a high degree of precision. The use of AC motor drives has also resulted in energy savings and improved system efficiency. This paper reviews the development and application of inverter technology to AC motor drives and presents a vision for motor drive technology.
In recent years, gearbox technology has advanced and original equipment manufacturers (OEMs) have specified
required gear oils to meet the lubrication requirements of these new designs. Modern gearboxes operate under severe conditions while maintaining their reliability to ensure end-user productivity. The latest generation of industrial gear lubricants can provide enhanced performance—even under extreme operating conditions—for optimal reliability and reduced cost of operation.
Based on simulation methods and calculation tools developed by the Schaeffler Group and presented in the first part of this paper, three approaches regarding increased efficiency based on rolling bearings are presented.