Temperature characteristics analysis of axial piston pump port plate pair

2019 ◽  
Vol 71 (4) ◽  
pp. 603-609
Author(s):  
Zhaoqiang Wang ◽  
Jun Cheng ◽  
Hong Ji ◽  
Shan Hu ◽  
Hao Chen
Keyword(s):  
Temperature Rise ◽  
Experimental Results ◽  
Oil Viscosity ◽  
Content Type ◽  
Temperature Characteristics ◽  
Oil Film ◽  
Characteristics Analysis ◽  
Belt Width ◽  
Relationship Of ◽  
The Mathematical Model

Purpose The purpose of this paper is to study the effects of single parameters for temperature characteristics of oil film in port plate pair and the relationship of calculated results and experimental results under different viscosity. Design/methodology/approach The paper established the mathematical model of oil film of port plate pair, calculated the energy equation of port plate pair, simulated for the oil film and temperature distribution and selected different kinds of lubricants to analyze the calculated value and the experimental value. Findings The results show: temperature rise of port plate pair is reduced with the increase of oil viscosity; temperature rise of port plate pair is decreased with rise of initial oil film thickness; temperature rise of port plate pair is increased with the rise of cylinder body speed, inclination angle and sealing belt width; and through the comparison of calculated value and experimental value, under the same viscosity and cylinder speed, experimental results are bigger. Originality/value This paper used the methods that the temperature of port plate pair was calculated numerically, and the results were consistent with experimental results, so it can get high precision.

Fusion monitoring of friction temperature rise of mechanical brake based on multi-source information and AI technology

Sensor Review ◽  
2020 ◽  
Vol 40 (3) ◽  
pp. 367-375
Author(s):  
Yan Yin ◽  
Heng Zhou ◽  
Jiusheng Bao ◽  
Zengsong Li ◽  
Xingming Xiao ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Temperature Rise ◽  
Experimental Results ◽  
Support Vector ◽  
Single Source ◽  
Source Information ◽  
Content Type ◽  
Temperature Characteristics ◽  
Monitoring Model ◽  
Friction Temperature

Purpose This paper aims to overcome the defect of single-source temperature measurement method and improve the measurement accuracy of FTR. The friction temperature rise (FTR) of brake affects braking performance seriously. However, it was mainly detected by single-source indirect thermometry, which has obvious deviations. Design/methodology/approach A three-point temperature measurement system was built based on three kinds of single-resource thermometry. Temperature characteristics of these thermometry were analyzed to achieve a standard FTR curve. Two fusion-monitoring models for FTR based on multi-source information were established by artificial neural network (ANN) and support vector machine (SVM). Findings Finally, the two models were verified based on the experimental results. The results showed that the fusion-monitoring model of SVM was more accurate than that of ANN in monitoring of FTR. Originality/value Then the temperature characteristics of the three single-source thermometry were analyzed, and the fusion-monitoring models based on multi-source information were established by ANN and SVM. Finally, the accuracy of the two models was compared by the experimental results. The more suitable fusion-monitoring model for FTR monitoring was determined which would be of theoretical and practical significance for remedying the monitoring defect of FTR.

Thermal elastohydrodynamic lubrication characteristics and optimisation of the ball-type tripod universal joint

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuqin Yang ◽  
Xiaojie Han ◽  
Mingqing Si
Keyword(s):  
Elastic Modulus ◽  
Film Thickness ◽  
Temperature Rise ◽  
Elastohydrodynamic Lubrication ◽  
Lubricating Oil ◽  
Universal Joint ◽  
Oil Viscosity ◽  
Content Type ◽  
Oil Film ◽  
Lubrication Characteristics

Purpose This paper aims to study the influence of three-column groove shell radius, ball radius, lubricating oil viscosity and elastic modulus on the thermal elastohydrodynamic lubrication (TEHL) characteristics and optimisation of the ball-type tripod universal joint. Design/methodology/approach The point contact TEHL model of the joint was developed, and the multi-grid method was used to solve it. The influence of three-column groove shell radius, ball radius, lubricating oil viscosity and elastic modulus on the lubrication characteristics was analysed. Further, the optimisation of the joint TEHL performance was carried out by the Kriging approximation model combined with the multi-objective particle swarm optimisation (MOPSO) algorithm. Findings The research results show that increasing groove shell radius and ball radius can effectively increase the oil film thickness, and decrease the oil film pressure, as well as the temperature rise. Decreasing elastic modulus can reduce the oil film temperature rise and pressure, and increasing viscosity can effectively increase the oil film thickness. The optimised minimum oil film thickness increases by 33.23% and the optimised maximum oil film pressure and maximum temperature rise decrease by 11.92% and 28.87%, respectively. Furthermore, the relative error of each response output is less than 10%. Originality/value This study applies TEHL theory to the tribological research of the ball-type tripod universal joint, and the joint’s lubrication performance is improved greatly by the Kriging model and MOPSO algorithm, which provides an effective measure to raise the joint’s working efficiency.

Experimental research on the tilting pad bearing under the high temperature of inlet oil

2018 ◽  
Vol 70 (6) ◽  
pp. 935-941 ◽  
Author(s):  
Peiji Yang ◽  
Qi Yuan ◽  
Runlin Chen
Keyword(s):  
High Temperature ◽  
Film Thickness ◽  
Temperature Rise ◽  
Measurement Method ◽  
Experimental Results ◽  
Test Results ◽  
Content Type ◽  
Oil Film ◽  
Tilting Pad ◽  
Shaft Vibration

Purpose The purpose of this study is to analyze the influence of high-temperature inlet oil on the comprehensive performance of tilting-pad bearing. Design/methodology/approach Taking a tilting-pad bearing under high temperature of inlet oil in a natural gas compressor as an example, the experimental system was developed for the tilting-pad bearing applied in a real machine, and the experiment was performed. The bearing lubricating properties under different high temperatures of inlet oil were obtained, including oil film thickness on the pivot, temperature rise and the shaft vibration values at the bearing positions. Findings The experimental results showed that the vibration, the oil film thickness on the pivot and the pad temperature were not sensitive to the change in temperature of the inlet oil, but vibrations were observed under the specific speed. At the same speed, when oil temperature changed by 1°C, the bearing temperature rise did not exceed 0.2°C and change in oil film thickness on the pivot was 1 µm. The test results of the actual unit are in good agreement with the experimental results. Originality/value The vibration measurement scheme was presented, and an indirect measurement method of fulcrum thickness was proposed. The practicability of the measurement method and the accuracy of test results were verified by the comparison of the test results of the shaft vibration, the bearing pad temperature, the fulcrum oil film thickness and the theoretical calculation results. This study will provide an important reference for designing a tilting-pad bearing with high-temperature inlet oil.

Size effect on thermal elastohydrodynamic lubrication of industrial chain bush-pin hinge pair

2019 ◽  
Vol 71 (9) ◽  
pp. 1080-1085 ◽  
Author(s):  
Mingyu Zhang ◽  
Jing Wang ◽  
Yi Liu ◽  
Longjie Dai ◽  
Zhaohua Shang
Keyword(s):  
Friction Coefficient ◽  
Film Thickness ◽  
Temperature Rise ◽  
Elastohydrodynamic Lubrication ◽  
Curvature Radius ◽  
Line Contact ◽  
Content Type ◽  
Oil Film ◽  
Industrial Chain ◽  
Infinite Line

Purpose The purpose of this paper is to use elastohydrodynamic lubrication (EHL) theory to study the variation of the equivalent curvature radius “R” on the change of oil film thickness, pressure, temperature rise and friction coefficient in the contact zone between bush-pin in industrial chain drive. Design/methodology/approach In this paper, the contact between bush and pin is simplified as infinitely long line contact. The lubrication state is studied by numerical simulation using steady-state line contact thermal EHL. The two constitutive equations, namely, Newton fluid and Ree–Eyring fluid are used in the calculations. Findings It is found that with the increase of equivalent curvature radius, the thickness of oil film decreases and the temperature rise increases. Under the same condition, the friction coefficient of Newton fluid is higher than that of Ree–Eyring fluid. When the load increases, the oil film thickness decreases, the temperature rise increases and the friction coefficient decreases; and the film thickness increases with the increase of the entraining speed under the condition “R < 1,000 mm”. Research limitations/implications The infinite line contact assumption is only an approximation. For example, the distances between the two inner plates are 5.72 mm, by considering the two parts assembled into the inner plates, the total length of the bush is less than 6 mm. The diameter of the pin and the bore diameter of the bush are 3.28 and 3.33 mm. However, the infinite line contact is also helpful in understanding the general variation of oil film characteristics and provides a reference for the future study of finite line contact of chain problems. Originality/value The change of the equivalent radius R on the variation of the oil film in the contact of the bush and the pin in industrial chain drive was investigated. The size effect influences the lubrication characteristic greatly in the bush-pin pair.

Shaping Law and Motion Design in NC-ECM under Effect of Twiste Angle

2011 ◽  
Vol 128-129 ◽  
pp. 1010-1014
Author(s):  
Rui Wu ◽  
Dan Wen Zhang ◽  
Juan Sun
Keyword(s):  
Mathematical Model ◽  
Electrochemical Machining ◽  
Experimental Results ◽  
Working Face ◽  
Relationship Of ◽  
The Mathematical Model ◽  
The Relationship ◽  
Motion Design

The twiste angle has a great effect on shaping law and stability of Numerical Controlled Electrochemical Machining (NC-ECM) process. In order to avoid the disadvantages caused by twiste angle, a methode of study shaping law by dispersing cathode working face in NC-ECM was proposed, and a mathematical model of the shaping law with the effects of twiste angle has been established in this paper. The mathematical model disclosed the relationship of twiste angle β, feeding velocity vf and thickness of removal material h in NC-ECM. Theoretical and experimental results show the the mathematical model of shaping law described in this paper can be considered as a useful reference and is helpful for the analysis of the NC-ECM and general ECM process.

Study on oil starvation at the oil seal edge of the oil film of hydrostatic bearing with double rectangular cavity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shiqian Ni ◽  
Yanqin Zhang ◽  
Zhen Quan
Keyword(s):  
Temperature Rise ◽  
Friction Pair ◽  
Operating Conditions ◽  
Rectangular Cavity ◽  
Lubricating Oil ◽  
Heat Accumulation ◽  
Content Type ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Side Flow

Purpose When the clearance oil film of hydrostatic bearing friction pair is in critical lubrication state, the phenomenon of zero flow of local lubricating oil will aggravate the oil film temperature rise, which needs to be solved. Design/methodology/approach In this paper, the critical lubrication parameter equation and the oil film temperature rise mathematical model are derived for the new type q1-205 double rectangular cavity hydrostatic bearing. Based on a combination of theoretical analysis, simulation and experimental verification, this paper analyzes the flow characteristics and temperature rise characteristics of the lubricating oil when the hydrostatic bearing is in a critical lubrication state under different operating conditions and finally obtains the critical lubrication state of the oil film. Findings This study found that the numerical simulations and the derived formulas agree with the results. When the oil film is in critical lubrication, the cross-section side flow of the oil side is almost zero. The heat cannot be taken away in time, resulting in the local temperature rise of the oil film, which causes serious heat accumulation. Originality/value It is concluded that the operating condition parameters corresponding to the critical lubrication state provide a theoretical basis for the selection of actual hydrostatic bearing operating conditions, which is of great scientific significance.

Influence of structural parameters of friction pair on oil temperature rise in hydro-viscous clutch

2019 ◽  
Vol 72 (1) ◽  
pp. 79-85
Author(s):  
Zhibao Li ◽  
Fangwei Xie ◽  
Junyu Sun ◽  
Jie Zhu ◽  
Xudong Zheng ◽  
...  
Keyword(s):  
Temperature Rise ◽  
Two Phase Flow ◽  
Friction Pair ◽  
Structural Parameters ◽  
Outer Radius ◽  
Phase Flow ◽  
Two Phase ◽  
Content Type ◽  
Oil Film ◽  
Inner Radius

Purpose The purpose of this paper is to study the temperature characteristics of hydro-viscous clutch with different structure of friction disks and obtain the distribution of film temperature. Design/methodology/approach The mathematical model of oil film between friction disks with radial grooves is established. Based on the flow rate equation, the temperature rise equation of oil film is deduced. Considering two-phase flow, the temperature distribution in the oil shear stage and the effects of the ratio of inner radius to outer radius on film temperature rise is studied by using computational fluid dynamics (CFD) technology. Findings The results show that when input speed is constant, the increase in the ratio of inner to outer radius leads to an increase in the peak temperature and the decrease in the ratio results in a larger increasing rate of temperature. Originality/value These results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for the mechanism of temperature rise by considering the effect of two-phase flow.

“Please tidy up before leaving”: nudging Airbnb guests toward altruistic behavior

2019 ◽  
Vol 13 (4) ◽  
pp. 524-530 ◽  
Author(s):  
Paul Ranson ◽  
Daniel Guttentag
Keyword(s):  
Social Presence ◽  
Design Methodology ◽  
Field Experiments ◽  
Experimental Results ◽  
Altruistic Behavior ◽  
Content Type ◽  
The Social ◽  
Relationship Model ◽  
Social Market ◽  
Practical Implications

Purpose This study aimed to investigate whether increasing the social presence within an Airbnb lodging environment could nudge guests toward altruistic cleaning behaviors. Design/methodology/approach The study was based around a theoretical framework combining the social-market versus money-market relationship model, nudge theory and social presence theory. A series of three field experiments were conducted, in which social presence was manipulated to test its impact on guest cleaning behaviors prior to departure. Findings The experimental results confirmed the underlying hypothesis that an Airbnb listing’s enhanced social presence can subtly induce guests to help clean their rental units prior to departure. Originality/value This study is the first to examine behavioral nudging in an Airbnb context. It is also one of the first field experiments involving Airbnb. The study findings offer clear theoretical and practical implications.

scholarly journals Relationship of patient shame to working alliance and satisfaction: a preliminary investigation

2019 ◽  
Vol 14 (4) ◽  
pp. 251-263
Author(s):  
Daniel J. Carabellese ◽  
Michael J. Proeve ◽  
Rachel M. Roberts
Keyword(s):  
Patient Satisfaction ◽  
Working Alliance ◽  
Preliminary Investigation ◽  
Community Members ◽  
Content Type ◽  
Mediation Analyses ◽  
External Shame ◽  
Relationship Of ◽  
The Relationship

Purpose The purpose of this paper is to explore the relationship of two distinct variants of dispositional shame (internal and external shame) with collaborative, purpose-driven aspects of the patient–provider relationship (working alliance) and patient satisfaction. The aim of this research was to conduct a preliminary investigation into the relevance of dispositional shame in a general healthcare population. Design/methodology/approach In total, 127 community members (mean age 25.9 years) who reported that they had regularly seen a GP over the past year were recruited at an Australian university. Participants were asked to reflect on their relationship with their GP, and completed instruments assessing various domains of shame, as well as working alliance and patient satisfaction. Findings Non-parametric correlations were examined to determine the direction and strength of relationships, as well as conducting mediation analyses where applicable. Small, negative correlations were evident between external shame and working alliance. Both external and internal shame measures were also negatively correlated with patient satisfaction. Finally, the relationship of external shame to patient satisfaction was partially mediated by working alliance. Practical implications Both the reported quality of patient–provider working alliance, and level of patient satisfaction are related to levels of dispositional shame in patients, and working alliance may act as a mediator for this relationship. Originality/value The findings from this preliminary study suggest that internal and external shame are important factors to consider in the provision of medical care to maximise the quality of patient experience and working alliance.

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