The Development and Performance of an Electrostatic Generator Operating Under High Air Pressure

1937 ◽  
Vol 51 (2) ◽  
pp. 75-83 ◽  
Author(s):  
R. G. Herb ◽  
D. B. Parkinson ◽  
D. W. Kerst
Author(s):  
Amla Patil ◽  
Jay Raval ◽  
Tim Bangma ◽  
Immanuel Edinbarough ◽  
Bruce Tai ◽  
...  

This study characterized airborne microdroplet diameters and size distribution from two commercially available lubricants A and B for internal minimum quantity lubrication (MQL). The effects of air pressure, oil channel size, physical properties of lubricants on the resultant microdroplets and through-tool MQL drilling performance were studied. Airborne microdroplet diameters were highly sensitive to the coolant channel sizes and air pressure. Cluster method was used to divide microdroplets into smaller clusters for comparison. Experimental data show that the average airborne microdroplet of lubricant B was larger than that of lubricant A at different air pressures and channel sizes. The contact angle of lubricant A was at least 10° less than that of lubricant B when depositing on glass or aluminium. High-speed imaging showed the tendency of more viscous lubricant B sticking to the drill tip, and higher pressure and longer time was required to atomize this viscous oil. Built-up-edges were less significant when drilling A380 aluminium with lubricant A. Due to high machinability of A380 aluminium, variation of hole diameter and hole cylindricity were minimal when drilling with different lubricants. Insignificant improvement in hole quality was observed when drilling with excessive amount of MQL lubricants or high concentration of lubricant C in flood coolant.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hongbo Liu ◽  
Guodong Sun ◽  
Dexu Geng ◽  
Junye Li

An antagonistic pneumatic bidirectional rotary flexible joint was developed to improve both safety and environmental adaptability of service robots and associated human interactions. The joint comprises two semicircular rotary actuators with positive and negative symmetrical distributions and a pneumatic brake. As such, it achieves forward and reverse rotations, and its damping and braking are adjustable in real time, enabling it to maintain its position. According to the force/torque balance at the free end of the rotary actuator, the rotation angle static model was established. The relationship between the actuator rotation angle, driving torque, impedance torque, and air pressure was obtained experimentally. The brake airbag was manufactured using additive manufacturing and silicone gel casting technologies. The mathematical model of the braking torque was established next, and the model was verified through experiments. Furthermore, an experimental system was constructed to carry out the air pressure-angle, air pressure-torque, and speed response experiments without the load on the joint. The results have shown that the joint can achieve any position within ± 68.5° when the driving air pressure varies from 0 to 0.30 MPa; the time required to reach the maximum angle was 0.85 s. The joint has shown good adjustable damping characteristics. Lastly, the braking torque reached 4.21 Nm at 0.32 MPa, effectively maintaining the position.


1936 ◽  
Vol 49 (10) ◽  
pp. 761-776 ◽  
Author(s):  
L. C. van Atta ◽  
D. L. Northrup ◽  
C. M. van Atta ◽  
R. J. van de Graaff

1938 ◽  
Vol 53 (8) ◽  
pp. 642-650 ◽  
Author(s):  
D. B. Parkinson ◽  
R. G. Herb ◽  
E. J. Bernet ◽  
J. L. McKibben

2019 ◽  
Vol 13 (3) ◽  
pp. 204-212
Author(s):  
Seyed Hadi Seyedin ◽  
Majid Ahmadi ◽  
Seyed Vahid Seyedin

This paper focuses on the structure and performance of the pressure swirl nozzle and the study of liquid atomization. In this study, the atomizer has been designed and some experiments have been performed on it. Since image processing is an efficient method for measuring the size of the droplet and since it considerably reduces the total measuring time and eliminates the subjective observer’s error in sizing and counting spray drops, a digital camera has been used for capturing images and image processing has been done by the MATLAB software. The results show that by increasing the atomization air pressure, the spray angle increases and the droplet’s size decreases. It is concluded that the spray angle is a function of the atomization air pressure and orifice diameter. Moreover, when the distance from the spray centre line increases, the droplet’s average velocity decreases.


1935 ◽  
Vol 6 (9) ◽  
pp. 261-265 ◽  
Author(s):  
R. G. Herb ◽  
D. B. Parkinson ◽  
D. W. Kerst

Author(s):  
A. L. Bespalov ◽  
I. G. Svidrak ◽  
O. O. Boiko

Under modern conditions vibrating hopper feeders with electromagnetic drive are irreplaceable when it comes to production processes in mechanical engineering and instrument making optimization processes. They are used to download small, medium or miniature details to automated technological equipment, such as automatic machines, automatic lines and automated complexes, or any other flexible automated production. The vibrating hopper loading devices are most commonly used in transportation and loading of details on working positions of assembly automatic machines and assembly automated complexes. In this case the details must be issued in a clearly oriented state. For this purpose, the stationary automated orienting devices, or the orienting devices located directly on the working vibrating feeders` bodies are used. Low compressed air pressure is often used in these devices. Apart from this, in some cases the low compressed air pressure is used in vibrating feeders to increase the maximum lifting angle when vibrating transportation of details on a transport tray of the feeder. We already know the designs of vibrating feeders, whose transport tray is equipped with channels and openings for the supply of compressed air, whose jets affect the parts that are transported in order to increase the maximum possible lifting angle or the speed of parts transportation, as well as to ensure the guaranteed gap between them at the download position. We also know the vibrating feeders` constructions equipped with jet pneumatic devices, which are set exactly on the vibrating feeder hopper and serve for non-contact orientation of details that are issued. All of these devices use the low compressed air supplied by means of the flexible pipeline from a workshop pneumatic network. But the fact that such network is simply absent in many enterprises` workshops makes it impossible to use the vibrating feeders like these, this way decreasing their use. For expanding their use it is necessary to have vibrating feeders with individual low pressure compressed air source. Modern production manufactures new models of machines with high technical economic indicators, so functionality increase  of the existing one equipment and the development of new schemes of machines is an important task for designers and technological equipment manufacturers, because minimal improvement of its technological and performance can lead to a significant economic effect. The set of elements affecting the performance and efficiency of vibrating bunker feeders with electromagnetic drives that have a directional elastic system are presented in this paper. The additional structural elements increasing the functionality of such feeders are offered.


2016 ◽  
Vol 28 (6) ◽  
pp. 780-793 ◽  
Author(s):  
Yalcin Yesil ◽  
Gajanan S. Bhat

Purpose Recently, the usage of melt blown products in many areas has increased. In melt blown process, generally polymers have been used. There are a variety of polymers. Characteristics of melt blown nonwovens have changed significantly depending on the polymer type. Also, there are several parameters such as die temperature, die-to-collector distance (DCD), air pressure, etc. that modify the nonwovens in melt blown process. The purpose of this paper is to investigate the effect of these parameters on the characteristics of nonwovens made up of polyethylene (PE). Design/methodology/approach In the melt blown process, two die temperatures, three different die air pressures and three different DCDs were used. In total, 18 samples were produced. On produced samples, thickness, tear and tensile strengths, fiber diameter, basis weight tests were done. Also SEM observations were obtained. Findings It was observed that parameters studied have a significant effect on characteristics of the produced nonwoven. Fiber diameter, basis weight and strength decrease by depending on factors. Also, it was observed that temperature has an effect, but slight. This work shows that higher temperatures should be studied. Finer and uniform fiber diameter is obtained with an increase in air pressure. Research limitations/implications PE is becoming increasingly important in nonwovens due to its lower melting point for processing and softer feel in nonwoven products. Practical implications Although the use of PE in polymer-laid nonwovens, especially as bicomponent fibers, has been growing in recent years, there are limited data on their processability and performance. In this context, with the availability of relatively higher melt flow rate PE, understanding the processability and structure and properties of the melt blown PE is very helpful in designing and developing the right products. This research was conducted to evaluate the processability of the PE resin using a typical PP melt blowing pilot line and to determine the structure and properties of the formed webs. Originality/value PE has superior properties such as excellent chemical resistance, good fatigue, wear resistance and higher impact strength. Also, PE provides good resistance to organic solvents, degreasing agents and electrolytic attack. PE has lower working temperatures than polypropylene, is light in weight, resistant to staining and has low moisture absorption rates. Thus, this study provides important contributions to the area since there are no data reported about the effect of various processing parameters on the structure and properties of PE melt blown nonwovens.


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