Experimental Study of the Skewed-Roller Slipping Clutch under Grease Lubrication

2011 ◽  
Vol 121-126 ◽  
pp. 152-156
Author(s):  
Ming Feng ◽  
Jun Wei Lian ◽  
Yong Li

Under the condition of grease lubrication, the skewed-roller slipping clutch was experimentally studied. The experimental bench was built up and the influences of geometrical parameters and operation conditions on torque ripple and temperature rising were clarified by the experiment, which laid the foundation for practical application of the skewed-roller slipping clutch in grease lubrication.

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1848
Author(s):  
Ahmed Hemeida ◽  
Mohamed Y. Metwly ◽  
Ayman S. Abdel-Khalik ◽  
Shehab Ahmed

The transition to electric vehicles (EVs) has received global support as initiatives and legislation are introduced in support of a zero-emissions future envisaged for transportation. Integrated on-board battery chargers (OBCs), which exploit the EV drivetrain elements into the charging process, are considered an elegant solution to achieve this widespread adoption of EVs. Surface-mounted permanent-magnet (SPM) machines have emerged as plausible candidates for EV traction due to their nonsalient characteristics and ease of manufacturing. From an electric machine design perspective, parasitic torque ripple and core losses need to be minimized in integrated OBCs during both propulsion and charging modes. The optimal design of EV propulsion motors has been extensively presented in the literature; however, the performance of the optimal traction machine under the charging mode of operation for integrated OBCs has not received much attention in the literature thus far. This paper investigates the optimal design of a six-phase SPM machine employed in an integrated OBC with two possible winding layouts, namely, dual three-phase or asymmetrical six-phase winding arrangements. First, the sizing equation and optimized geometrical parameters of a six-phase 12-slot/10-pole fractional slot concentrated winding (FSCW)-based SPM machine are introduced. Then, variations in the output average torque, parasitic torque ripple, and parasitic core losses with the slot opening width and the PM width-to-pole pitch ratio are further investigated for the two proposed winding layouts under various operation modes. Eventually, the optimally designed machine is simulated using analytical magnetic equivalent circuit (MEC) models. The obtained results are validated using 2D finite element (FE) analysis.


Author(s):  
Jianping Yuan ◽  
Rong Jin ◽  
Shujuan Li ◽  
Longyan Wang ◽  
Aixiang Ge

In order to research the influence laws of the main geometrical parameters of auxiliary impeller and different operation conditions on the centrifugal pump with an auxiliary impeller, which aimed to act as dynamic seal, the orthogonal experiment was designed with four factors and three values. The factors respectively are auxiliary impeller axial clearance, blade width, outlet diameter and blade number. With simulation by Fluent, major and minor factors were investigated which influence the performance of the centrifugal pump with an auxiliary impeller. The cases with optimization sealing pressure value and optimization efficiency were obtained and it was proved by the experimental results. Then, two optimization cases and the original case were simulated and analyzed. The research results show that the major factor of auxiliary impellers for the pump efficiency is the outlet diameter. For sealing pressure head of auxiliary impellers, the major factor is the outlet diameter of auxiliary impeller and the axial clearance and blade number of the auxiliary impeller are secondary important factors. For the optimization of centrifugal pumps with an auxiliary impeller, numerical orthogonal tests can replace actual orthogonal tests.


2015 ◽  
Vol 5 (4) ◽  
pp. 86-92 ◽  
Author(s):  
Mikhail Ivanovich BALZANNIKOV

Considered run-of-river hydropower plants (HPP). Notes the importance of technical-economic calculations in the justifi cation of large water-conducting elements of the path these types of HPP. The methodology of economic substantiation of the expediency of increasing the length of the draft tube. Using the technique of the calculations for lowpressure hydroelectric run-of-river type. The results of the analysis of the influence of the operating conditions of the hydroelectric power station on basic geometrical parameters of draft tube.


Author(s):  
Houda Hachem ◽  
Ramla Gheith ◽  
Fethi Aloui ◽  
Sassi Ben Nasrallah

Considering Stirling engines modern applications and cogeneration recovery energy from industrial process, the power of a Stirling prime mover is to be provided at a speed of rotation adapted to the operation of the receiver system (usually a generator) to exploit the performance of this machine under the conditions of its use (ie lowering of the rotational speed and torque transmitted rise or, more rarely, elevated speed and lowering the torque transmitted). Knowing that the hot air engine cannot change speed quickly and in order to have a well designed system, it is important to study the unsteady state conditions. In this work we present an experimental stability analysis of an irreversible heat engine working at different conditions. The experimental study aims at analyzing the effect of working parameters disruption on the stability of the Gamma Stirling engine. Parameters involved in this experimental study are the load pressure of the motor and the load applied to the Stirling engine. The influence of engine operating parameters on its torque and rotational speed is investigated. The time required by a gamma type Stirling engine to stabilize operation after disruption is estimated. Results show that after a small disruption, speed and temperature evolutions decays exponentially to the steady state determined by a relaxation time. It is assumed that the decrease of the applied power load to the engine or the increase of the load pressure leads to a speed up. And that the increase of the applied power load to the engine or the decrease of the load pressure leads to a speed down.


2016 ◽  
Vol 870 ◽  
pp. 276-281 ◽  
Author(s):  
V.V. Goman ◽  
S.A. Fedoreev

The paper describes the method and results of laboratory tests with several types of demountable contact joints and operation tests at functional power industry facilities. The contacts without protective coating are compared with contacts with the protective light-alloy-based coating applied according to the authors’ technology. It is demonstrated that the technology is applicable in real electric equipment operation conditions.


2012 ◽  
Vol 433-440 ◽  
pp. 18-23
Author(s):  
Xiao Liu ◽  
Yuan Fu Cao ◽  
Ti En Zhang

Experiments of the valve bridge are carried out and the boiling states are investigated, to study the boiling heat transfer in cylinder head jacket. The effects of inlet flow rate and temperature on boiling heat flux are analyzed, as well as the thickness of fire deck. The results show that the inlet velocity has little effect on the velocity in valve bridge zone, even the velocity in the valve bridge zone can strongly affect on boiling heat transfer. The results can offer references to practical application in power-enhanced diesel engine.


2014 ◽  
Vol 13 (2) ◽  
pp. 283-290
Author(s):  
Błażej Meronk ◽  
Krzysztof Wilde

The paper presents the experimental study on the diagnostics of concrete elements with the use of nonlinear acoustic effects. The tests were conducted on a concrete plate subjected to ultrasonic waves modulated with and without an additional low frequency actuator. The experimental results showed that the new method based on the direct modulation of diagnostic ultrasonic waves also provided sub-harmonic frequencies that indicated the presence of damage. The new method does not require a low frequency actuator for generation of low frequency oscillations, and therefore, is more suitable for practical application.


2020 ◽  
Vol 2020 (6) ◽  
pp. 12-21
Author(s):  
Ruslan Guchinskiy

The optimum value choice of a tightening effort is significant for assurance of a reliable operation of a group bolted joint. A work goal consists in the calculation and comparison of essential conditions of tightening efforts for a bolted joint of a bracket and a plate with analytical and numerical methods. For the first time it is obtained that the use of tightening factors recommended in literature by the condition of joint density may fail to ensure its non-disclosure. It is shown that a basic load factor for a bolt of a group joint depends not only upon bolt and flanges yielding, but upon loading and geometrical parameters of a joint. Basic loading factors obtained through a finite element method for a group bolted joint proved to be below ones defined analytically. The use of the procedure for bolt calculations on the basis of the assurance of joint complete non-disclosure results in increased values of tightening efforts caused by non-uniformity of contact stress distribution in flanges because of tightening. There is specified a field of application of the calculation procedure on joint non-disclosure – group joints with high stiffness flanges. At preliminary estimate the efforts for tightening a standard group joint a procedure of joint non-disclosure with the increased tightening factor and a condition of shift absence is recommended for use. To obtain a reliable estimate of the required tightening effort after its preliminary selection it is recommended to check up operation conditions of a group bolted joint with the aid of the calculation through the finite element method.


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