Film riding seals for rotary machines

2014 ◽  
Vol 2014 (9) ◽  
pp. 13
Keyword(s):  
Rotary Machines

Extended Angular-Velocity Vold–Kalman Order Tracking

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Min-Chun Pan ◽  
Cheng-Xue Wu
Keyword(s):  
Angular Velocity ◽  
Planetary Gear ◽  
Transmission System ◽  
Theoretical Derivation ◽  
Order Tracking ◽  
Electric Scooter ◽  
Rotary Machines ◽  
Machine Elements ◽  
Order Components

Dynamic signals acquired from rotary machines can be characterized by the order tracking (OT) techniques. The extracted order components correspond to the operation of specific machine elements and reflect their current healthy or faulty states. The study extends the angular-velocity Vold–Kalman OT scheme to simultaneously extract multiple order components. Theoretical derivation is illustrated with simulation of processing three synthetic signals to show its merit. Additionally, as an example to validate its effectiveness, the improved OT scheme is used to process pass-by noise emitted from an electric scooter with a planetary-gear-set transmission system. The gear-meshing orders are effectively decoupled from structure-borne resonances.

scholarly journals Comparison of the Stator Step Skewed Structures for Cogging Force Reduction of Linear Flux Switching Permanent Magnet Machines

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2172 ◽  
Author(s):  
Wenjuan Hao ◽  
Yu Wang
Keyword(s):  
Finite Element Analysis ◽  
System Performance ◽  
Thrust Force ◽  
Low Cost ◽  
Good Choice ◽  
Permanent Magnet Machines ◽  
Maximum Difference ◽  
Element Analysis ◽  
Rotary Machines ◽  
Force Reduction

Linear flux switching permanent magnetic (LFSPM) machines, with the armature windings and magnets both on the mover in addition to a robust stator, are a good choice for long stoke applications, however, a large cogging force is also inevitable due to the double salient structure, and will worsen the system performance. Skewing methods are always employed for the rotary machines to reduce the cogging torque, and the rotor step-skewed method is a low-cost approximation of regular skewing. The step skewed method can also be applied to the linear machines, namely, the stator step skewed. In this paper, three stator step skewed structures, which are a three-step skewed stator, a two-step skewed stator and an improved two-step skewed stator, are employed for the cogging force reduction of two types of LFSPM machines. The three structures are analyzed and compared with emphasize on the influence of the skewed displacement on the cogging force and the average thrust force. Based on finite element analysis (FEA), proper skewed displacements are selected according to maximum difference between the reduction ratio of the cogging force and the decrease ratio of the average thrust force, then, the corresponding results are compared, and finally, valuable conclusions are drawn according to the comparison. The comparison presented in this paper will be useful to the cogging force reduction of LFSPM machines in general.

Application of Artificial Intelligence to Gearbox Fault Diagnosis

2016 ◽  
pp. 536-562
Author(s):  
Anand Parey ◽  
Amandeep Singh Ahuja
Keyword(s):  
Artificial Intelligence ◽  
Fault Diagnosis ◽  
Power Plants ◽  
Human Life ◽  
Propulsion Systems ◽  
Marine Propulsion ◽  
Rotary Machines ◽  
Domestic Appliances ◽  
Financial Losses ◽  
Significant Milestone

Gearboxes are employed in a wide variety of applications, ranging from small domestic appliances to the rather gigantic power plants and marine propulsion systems. Gearbox failure may not only result in significant financial losses resulting from downtime of machinery but may also place human life at risk. Gearbox failure in transmission systems of warships and single engine aircraft, beside other military applications, is unacceptable. The criticality of the gearbox in rotary machines has resulted in enormous effort on the part of researchers to develop new and efficient methods of diagnosing faults in gearboxes so that timely rectification can be undertaken before catastrophic failure occurs. Artificial intelligence (AI) has been a significant milestone in automated gearbox fault diagnosis (GFD). This chapter reviews over a decade of research efforts on fault diagnosis of gearboxes with AI techniques. Some of areas of AI in GFD which still merit attention have been identified and discussed at the end of the chapter.

scholarly journals Deforming grid generation for numerical simulations of fluid dynamics in sliding vane rotary machines

2017 ◽  
Vol 112 ◽  
pp. 180-191 ◽  
Author(s):  
Giuseppe Bianchi ◽  
Sham Rane ◽  
Ahmed Kovacevic ◽  
Roberto Cipollone
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulations ◽  
Grid Generation ◽  
Rotary Machines

Failures of avionic generators and contactors operated under harsh ambient conditions

2012 ◽  
Vol 30 (1) ◽  
pp. 153-176
Author(s):  
Andrzej Gębura ◽  
Tomasz Radoń
Keyword(s):  
Climatic Conditions ◽  
Ambient Conditions ◽  
Power Devices ◽  
Lower Intensity ◽  
Fine Grained ◽  
Rotary Machines ◽  
Paint Coatings ◽  
Corrosion Pits ◽  
Fine Grained Sand ◽  
Final Consequence

The paper outlines failures of selected avionic electric power devices operated onboard of combat helicopters in Iraq and Afghanistan. While the authors were examining the electric power system of aircrafts in order to prolong their operation life they paid attention to numerous symptoms of wear demonstrated by some units of aircrafts. It was peculiar that such symptoms have never appeared during similar examinations of aircrafts operated in our country. By all accounts, the weird wear of components results from high intensity of flights and specific features of operating missions, but harsh climatic conditions seem to be the crucial factor. The authors believe that many of spotted failures experienced by electric power equipment may also happen to aircrafts operated in Poland but obviously, due to much lower intensity of operation and mild impact of environmental factors, such failures shall occur much later. The authors focused their attention on two groups of electric devices and associated destructive factors: 1. Air-cooled electric rotary machines. Fine-grained sand sucked together with air leads to very quick abrasion of protective paint coatings inside the machines. Not frequent but intense rainfalls are the reason for appearance of corrosion pits that lead to such effects as increase of pole shoe volumes. This, in turn, results in shearing of winding insulations with breakdowns (shorts) to ground and, as a final consequence, considerable drop of power demonstrated by an electric machine. 2. Contactors and electromagnets, which are allegedly tight. However, dust penetrates anyway via microfissures and disables operation of moving parts.

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