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Design and Analysis of an Example Lathe Spindle
No full textThis paper discusses the modeling and analysis of an example medium speed medium precision lathe spindle. This and few other similar topics have been assigned as term projects in an introductory senior undergraduate/graduate level finite element analysis course taught at Kettering University. The experiences and the general feedback from the students of the class show satisfactory organization of the course material that includes modeling and analysis of real life examples
Easily Implantable and Stable Nail-fastener for Skeletal Fixation and Method
Get PDFAn intramedullary nail (20) defining a bore (34) is inserted into a medullary canal (26) of a bone (24). A threaded fastener (22) has a compression portion (48) presenting a compression portion diameter (DCP) and a threaded portion (50) presenting a threaded portion diameter (DTP). The fastener (22) extends through a near cortex hole (40) and/or a far cortex hole (42), and the threaded portion (22) threadedly engages the bore (34). A compression transmission device (54) is disposed between a head (44) of the fastener (22) and the intramedullary nail (20) for transmitting the compressional load of the threaded fastener (22) to the intramedullary nail (20). An interior space of the compression transmission device (54) is greater than the compression portion diameter (DCP) providing space about the threaded fastener (22) for allowing the fastener axis (A) to be variously disposed relative to the interior space
Design of a High-Efficiency Minimum-Torque-Ripple 12-V/1-kW Three-Phase BLDC Motor Drive System for Diesel Engine Emission Reductions
No full textA 12-V motor drive system using an onboard battery is promising in vehicle applications, e.g., to rotate an air pump to adjust its air delivery to the burner, thereby providing autonomous exhaust temperature control for the conventional diesel engine vehicle. The 12-V/1-kW motor drive system proposed in this paper consists of a series-resonant LLC MOSFET full-bridge converter, which provides high-efficiency power transfer by implementing zero voltage switching and boosts the dc bus to ~300 V, and an insulated-gate bipolar transistor inverter, which provides the high-side phase currents to a 1-kW/6000-r/min brushless dc motor (BLDC). This design secures the high efficiency, low cost, and low volume. Meanwhile, with the variable output voltage of this dc/dc converter, this paper realizes a commutation torque-ripple reduction method, which will minimize the mechanical vibration. Experimental results on this prototype system demonstrate that: 1) the LLC dc/dc part efficiency is 97.6% with 92% of the inverter efficiency; and 2) the motor commutation torque ripple is reduced close to zero
A Hybrid Observer for the Full-speed-range Sensorless Control of Interior Permanent Magnet Motor Drives
No full textThis paper presents a method for the sensorless control in full speed range for an interior permanent-magnet synchronous motor (IPM). At standstill and very low speed region, high frequency (HF) injection technique is used to detect the rotor initial position. A hybrid observer is applied to realize a smooth transition from low to high speed. When the rotor speed goes up to a certain value where back EMF can provide adequate information, a back EMF observer will dominate. The hybrid observer is verified through simulation and experimental results using a three-phase 1-kW IPM motor drive
Atmospheric Plasma Surface Modification of PMMA and PP Micro‐Particles
No full textChemical surface modification of polymethylmethacrylate (PMMA) and polypropylene (PP) particles was achieved using a continuous atmospheric plasma process, resulting in increased oxidation and hydrophilicity. Contact angles of treated PMMA ranged from 79–117° (125° for untreated). Air plasma produced higher contact angles than pure nitrogen, which is attributed to primary surface degradation from oxygen. Higher energy and flow rate of water resulted in decreased contact angles. Treated PP mixed in water upon agitation, while untreated PP remained at the surface. X‐ray photoelectron spectroscopy (XPS) showed increased CO and CO for treated samples. The addition of 10% hydroxyethylmethacrylate (HEMA) to water showed a slight decrease in contact angle, but no difference from pure water in XPS results
Side Impact Testing of the Near-Side, Rear Seat Occupant Using a Deceleration Sled
No full textA near-side, rear seat side impact component test, was conducted and validated utilizing a SIDIIs anthropomorphic test device (ATD). The test fixture consisted of the rear seat structure, side door, interior trim, and side airbag curtain module. Test parameters were determined from full scale tests including impact speed, angle of impact, and depth of door intrusion. A comparative assessment was conducted between the full scale test and the deceleration sled test including ATD contact with the vehicle interior, contact duration, sequential timing of ATD contact, and dummy injury measures. Validation was achieved so that the deceleration sled test procedure could be utilized for further evaluations