scholarly journals Torque capacity of multidisc wet clutch with reference to friction occurrence on its spline connections

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcin Bąk

AbstractIn this article developed mathematical model that includes friction occurrence on spline connections is presented. The work also contains results of experimental research on torque capacity of multidisc wet clutch. These results are expressed as a function of contact pressure for different number of friction surfaces. Due to increased interest in research concerning multidisc wet clutches it is essential to determine impact of friction on fit connections on transmitted torque. Analytical calculations that include both known loss coefficient and assumed lack of friction on fit connections are compared to results of experiments. The paper contains detailed description of test stand and methodology of experiment. As a result of conducted tests it was found that correction coefficients known from literature are highly inaccurate. Measured values of torque indicate that transmitted torque reach significantly higher values. It was also revealed that after slippage appeared, the pressure plate usually moved in the direction of exerted clamping force, but movement in reversed direction also took place for some experiments. While movement corresponding to clamping force reached ca. 0.08 mm, in opposite direction amounted to 0.02 mm. Furthermore, studies presented that lapping of adjacent friction surfaces greatly affects differences between respective results obtained for a specific experiment.

2020 ◽  
Vol 16 (4) ◽  
pp. 333-337
Author(s):  
B. Faramarzi ◽  
M. Polniaszek ◽  
F. Dong

Proper hoof function is vital for equine health and performance. Many musculoskeletal injuries in horses originate from the foot. Most studies performed to date have focused on the forehoof while the hindhoof (HH) has received less attention. Our goal was to examine the influence of routine hoof trimming on HH medio-lateral hoof balance. The objective of this study was to examine force (F), contact pressure (CP), and contact area (CA) at the medial and lateral aspects of the HH to evaluate the impact of routine hoof trimming on HH biomechanics. Clinically sound Arabian horses (n=9) were walked across a calibrated pressure plate before and after routine hoof trimming and the F, CP, and CA at the medial and lateral aspects of the HH were recorded at midstance pre- and post-trimming. The differences between these regions were investigated using a paired T-test. P-values <0.05 were considered significant. Among measured variables, force increased by 25% (P=0.007) and contact pressure increased by 13% (P=0.032) at the medial aspect of the HH after routine hoof trimming. Analysing data from hindlimb hoof-surface interaction in sound horses will allow for a better understanding of imbalances that may lead to pathologies and hindlimb lameness in horses.


2019 ◽  
Vol 298 ◽  
pp. 00134
Author(s):  
Zhanna Tikhonova ◽  
Evgeniy Frolov ◽  
Dmitriy Krainev ◽  
Alexander Plotnikov

The article is devoted to the description of the experimental research method when developing a mathematical model for calculating the cutting speed based on information from the cutting zone obtained during the test run in the process of turning using steel coated tools as an example. This paper also presents the results of an experimental study which prove the effectiveness of applying the obtained mathematical dependence.


2018 ◽  
Vol 284 ◽  
pp. 281-288 ◽  
Author(s):  
Anatoly A. Fomin ◽  
V.G. Gusev ◽  
Zulfiya G. Sattarova

The geometrical interpretation of the transformation of cylindrical milling of products into profile milling by shaping cutters with a convex and concave cutting profile is considered. A mathematical model of geometric errors of profile surfaces processed with tools with the specified cutting profiles is developed. On the basis of the model and the results of its analysis, scientifically based recommendations for designing a technological operation for profile milling of products have been developed. When processing a product with a contoured cutter with a concave profile, it is recommended to calculate the geometric errors formed in the transverse plane of the shaping cutter, and when machining with a shaping cutter with a convex cutting profile - in the planes of both its ends. The calculated values of the above geometric errors should be compared with the values limited by the work drawing of the product. The implementation of these recommendations will reduce the labor costs for experimental research and control operations associated with ensuring a given geometric accuracy of products.


Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2866
Author(s):  
Jintong Liu ◽  
Anan Zhao ◽  
Piao Wan ◽  
Huiyue Dong ◽  
Yunbo Bi

Interlayer burrs formation during drilling of stacked plates is a common problem in the field of aircraft assembly. Burrs elimination requires extra deburring operations which is time-consuming and costly. An effective way to inhibit interlayer burrs is to reduce the interlayer gap by preloading clamping force. In this paper, based on the theory of plates and shells, a mathematical model of interlayer gap with bidirectional clamping forces was established. The relationship between the upper and lower clamping forces was investigated when the interlayer gap reaches zero. The optimization of the bidirectional clamping forces was performed to reduce the degree and non-uniformity of the deflections of the stacked plates. Then, the finite element simulation was conducted to verify the mathematical model. Finally, drilling experiments were carried out on 2024-T3 aluminum alloy stacked plates based on the dual-machine-based automatic drilling and riveting system. The experimental results show that the optimized bidirectional clamping forces can significantly reduce the burr heights. The work in this paper enables us to understand the effect of bidirectional clamping forces on the interlayer gap and paves the way for the practical application.


2010 ◽  
Vol 37-38 ◽  
pp. 234-237
Author(s):  
Xiao Jing Wang ◽  
Jun Peng Shao ◽  
Guang Bin Yu

In order to improve the low speed stationary of continuous rotary electro-hydraulic servo motor and avoid the pressure impact in the sealed cavity during the oil distributing, this paper designed the shape of buffer groove, established the mathematical model of pressure gradient, and analyzed change law of sealed cavity pressure gradient under different dimension of buffer groove. The pressure field distribution of sealed cavity was studied in certain radial and axial gap, and it is validated the dimension of buffer groove is rational, which lays foundation for structure design and experimental research of large displacement servo motor.


2014 ◽  
Vol 945-949 ◽  
pp. 1461-1464
Author(s):  
Han Yu Jin ◽  
Xiu Sheng Cheng ◽  
Xiu Feng Song

The working principle of wet clutch was analyzed and the mathematical model was established for torque deliver. Experimental verification and simulation analysis was carried out for the clutch model in the situation of constant pressure engaging process. An efficiency examination of wet clutch implemented on the test rig and provided theory evidence for pressure precisely control.


Author(s):  
Hugen Ma ◽  
Hui Gao ◽  
Wenjing Tu

Based on the single blow technique, experimental research was conducted for the performance of heat transfer and flow drop for six test cores with cross corrugated (CC) or corrugated undulated (CU) primary surfaces for different geometries. After the mathematical model was established for heat transfer under the condition of single blow, a matching numerical solution was obtained for different NTU. The correlations of hear transfer factor j and friction factor f were obtained for three types of cross corrugated primary surfaces (crossed angle 45∼75°) with a range of Re = 120∼800 and three types of corrugated undulated primary surfaces (crossed angle 52.5∼67.5°) with a range of Re = 200∼1200. Hydraulic diameters of all heat transfer surfaces are from 1.2∼1.48mm. Analysis on the flow and heat transfer for cross corrugated and corrugated undulated primary surfaces was made based on the comprehensive evaluating factor j/f. The experimental results were compared to references with good consistency. The regressive errors of correlations were less than 16%.


2018 ◽  
Vol 70 (2) ◽  
pp. 273-281 ◽  
Author(s):  
Xiaoshuang Xiong ◽  
Lin Hua ◽  
Xiaojin Wan ◽  
Can Yang ◽  
Chongyang Xie ◽  
...  

Purpose The purposes of this paper include studying the friction coefficient of polyoxymethylene (POM) under a broad range of normal load and sliding velocity; developing a mathematical model of friction coefficient of POM under a broad range of normal loads and sliding velocities; and applying the model to dynamic finite element (FE) analysis of mechanical devices containing POM components. Design/methodology/approach Through pin-on-disc experiment, the friction coefficient of POM in different normal loads and sliding velocities is investigated; the average contact pressure is between 5 and 15 Mpa and the sliding velocity is from 0.05 to 0.9 m/s. A friction algorithm is developed and embedded in the FE model to simulate the friction of POM in different normal loads and sliding velocities. Findings The friction coefficient of POM against steel declines with the increase of normal loads when the contact pressure is between 5 and 15 Mpa. The friction coefficient of POM against steel increases markedly when the sliding velocity is between 0.05 and 0.15 m/s, it decreases sharply between 0.15-0.45 m/s and then it stabilizes at high sliding velocity between 0.45 and 0.9 m/s. The friction coefficient of POM in different working operations has a significant effect on contact stress and shear stress. The simulation data and experiment data of POM friction force fit very well; therefore, it can be concluded that the friction algorithm and FE model are accurate. Originality/value The friction coefficient of POM under a broad range of normal loads and sliding velocities is investigated. The friction coefficient model of POM is established as a function of normal loads and sliding velocities in the dry sliding condition. A friction algorithm is developed and embedded in the FE model of the friction of POM. The mathematical model of the friction coefficient accurately agrees with the experiment data, and simulation data and experiment data of the POM friction force fit very well.


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