Application of Raise Boring Machine in the Main Shaft Extended Well of the JUNDE Coal

2021 ◽  
Vol 09 (02) ◽  
pp. 101-107
Author(s):  
灵姬 马
Keyword(s):  
Main Shaft

Creating the Wind Energy for Operating the 3-C-Section Blades Wind Car

2012 ◽  
Vol 622-623 ◽  
pp. 1188-1193 ◽  
Author(s):  
Hüseyin Çamur ◽  
Youssef Kassem
Keyword(s):  
Wind Speed ◽  
Angular Velocity ◽  
Wind Energy ◽  
Drag Force ◽  
Mechanical Energy ◽  
Main Shaft ◽  
Airflow Velocity ◽  
Low Speed ◽  
Low Wind Speed

The purpose of this work is to determine the drag characteristics and the torque of three C-section blades wind car. Three C-section blades are directly connected to wheels by using of various kinds of links. Gears are used to convert the wind energy to mechanical energy to overcome the load exercised on the main shaft under low speed. Previous work on three vertical blades wind car resulted in discrepancies when compared to this work. Investigating these differences was the motivation for this series of work. The calculated values were compared to the data of three vertical blades wind car. The work was conducted in a low wind speed. The drag force acting on each model was calculated with an airflow velocity of 4 m/s and angular velocity of the blade of 13.056 rad/s.

scholarly journals Study on the Unbalanced Curl Seal Failure of the Magnetorheological Fluid Sealing Device of the Hydraulic Turbine Main Shaft under Different Speed Abrupt Conditions

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1171
Author(s):  
Jie Cheng ◽  
Zheng-Gui Li ◽  
Yang Xu ◽  
Wang-Xu Li ◽  
Xin-Rui Li
Keyword(s):  
Magnetic Field ◽  
Sudden Change ◽  
Hydraulic Turbine ◽  
Frictional Heat ◽  
Main Shaft ◽  
Mr Fluid ◽  
Friction Heat ◽  
Sealing Ability ◽  
Sealing Failure ◽  
Sealing Device

The fluid flow in the runner of a hydraulic turbine has serious uncertainties. The sealing failure of the magnetorheological (MR) fluid sealing device of the main shaft of the hydroturbine, caused by a sudden change in speed, has always been a difficult topic to research. This study first derives the MR fluid seal pressure and unbalanced curl equations of the hydroturbine main shaft, and then analyzes the seal pressure and friction heat under different rotational speed mutation conditions through experiments. After verification, the temperature field and magnetic field distribution of the MR fluid sealing device of the main shaft of the hydraulic turbine are obtained via numerical calculation. The results show that the external magnetic field affects the magnetic moment of the magnetic particles in the MR fluid, resulting in a significant change in frictional heat, thereby reducing the saturation of magnetic induction intensity of the MR fluid. This results in a decrease in the sealing ability of the device. The size and abrupt amplitude of the main shaft of the hydraulic turbine, and friction heat is positively correlated reducing the sealing ability of the device and causing sealing failure. Based on our results, we recommend adding the necessary cooling to the device to reduce the frictional heat, thereby increasing the seal life of the device.

Kinematic design and motion analysis of spatial rapier drive mechanisms used in weaving machines

2014 ◽  
Vol 84 (19) ◽  
pp. 2065-2073 ◽  
Author(s):  
Recep Eren ◽  
Mesrur Erturk ◽  
Barıs Hascelik
Keyword(s):  
Motion Analysis ◽  
Kinematic Analysis ◽  
Gear Ratio ◽  
Main Shaft ◽  
Drive Mechanism ◽  
Spatial Mechanism ◽  
Kinematic Design ◽  
Shaft Angle

This paper presents an approach for the kinematic design of a rapier drive mechanism containing a spatial mechanism and analyses rapier motion curve. Kinematic design and analysis equations are derived and then the link lengths of the spatial mechanism are calculated in order to satisfy the critical rapier positions inside and outside the shed. In this way, the portions of one loom revolution, during which the rapiers are inside and outside the shed, are determined. The rapier motion curve is obtained by using kinematic analysis equations. It is shown that the position of the oscillating link in the spatial mechanism and the loom main shaft angle at which the rapier enters the shed have the most significant effect on the rapier motion curve. The gear ratio has also some effect on the rapier motion curve. Different rapier motion curves are obtained by changing these parameters and the suitability of these curves for rapier motion is discussed.

Endurance and Failure Characteristic of Main-Shaft Jet Engine Bearing at 3 × 106 DN

1976 ◽  
Vol 98 (4) ◽  
pp. 580-585 ◽  
Author(s):  
E. N. Bamberger ◽  
E. V. Zaretsky ◽  
H. Signer
Keyword(s):  
Ball Bearings ◽  
Main Shaft ◽  
Test Results ◽  
Jet Engine ◽  
Material Life ◽  
Thrust Load ◽  
Inner Race ◽  
Continuous Running ◽  
Life Factor ◽  
Engine Bearing

Groups of thirty 120-mm bore angular-contact ball bearings were endurance tested at a speed of 12 000 and 25 000 rpm (1.44 × 106 and 3.0 × 106 DN) and a thrust load of 66 721 N (5000 lb). The bearings were manufactured from a single heat of VIM-VAR AISI M-50 steel. At 1.44 × 106 and 3.0 × 106 DN, 84 483 and 74 800 bearing test hours were accumulated, respectively. Test results were compared with similar bearings made from CVM AISI M-50 steel run under the same conditions. Bearing lives at speeds of 3 × 106 DN with the VIM-VAR AISI M-50 steel were nearly equivalent to those obtained at lower speeds. A combined processing and material life factor of 44 was found for VIM-VAR AISI M-50 steel. Continuous running after a spall has occurred at 3.0 × 106 DN can result in a destructive fracture of the bearing inner race.

Considerations of the All Electric (Accessory) Engine Concept

1995 ◽  
Vol 209 (4) ◽  
pp. 273-280 ◽  
Author(s):  
R I Jones
Keyword(s):  
System Component ◽  
Electrical Machine ◽  
Main Shaft ◽  
Switched Reluctance Machine ◽  
Switched Reluctance ◽  
Design Considerations ◽  
Reluctance Machine ◽  
Starter Generator ◽  
Engine Concept ◽  
Engine Type

The concept of the all electric (accessory) engine (AEE) involves the use of an electrical machine integrated on an engine main shaft acting as a starter generator, providing power to both engine and airframe systems. Through removal of the various constraints caused by the present mechanical accessory drives, this concept apparently provides a number of advantages. However, the concept of an AEE has been around for some years and yet has not been adopted to-date. A brief review of electrical machine types previously considered as internally mounted starter/generators highlights basic problems of the concept. The reasons for favouring the Switched Reluctance Machine for this application are then explained and some present and planned developments on this basis outlined. An approximate sizing of starter/generators to replace shaft off-takes alone and bleed in additions in a civil turbofan application is presented, showing more detailed design considerations. Other system component aspects and concerns are also covered before addressing the effects on the ease of adopting the AEE concept of likely future changes to civil engines. Major differences relative to the civil case are indicated for other engine type applications. Conclusions are then drawn on the likely future of the AEE concept.

Failure analysis of a locomotive turbocharger main-shaft

2009 ◽  
Vol 16 (1) ◽  
pp. 495-502 ◽  
Author(s):  
Xu Xiaolei ◽  
Yu Zhiwei
Keyword(s):  
Failure Analysis ◽  
Main Shaft

Design optimization of an angular contact ball bearing for the main shaft of a grinder

2016 ◽  
Vol 104 ◽  
pp. 287-302 ◽  
Author(s):  
Seung-Wook Kim ◽  
Kibong Kang ◽  
Kichan Yoon ◽  
Dong-Hoon Choi
Keyword(s):  
Design Optimization ◽  
Ball Bearing ◽  
Main Shaft ◽  
Angular Contact Ball Bearing
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