Research on transmission efficiency of high power hydro-viscous clutch

2019 ◽  
Vol 71 (7) ◽  
pp. 942-948
Author(s):  
Qi Sun ◽  
Fangwei Xie ◽  
Kuaidi Wan ◽  
Xinjian Guo ◽  
Jie Zhu ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Inlet Pressure ◽  
Lubricating Oil ◽  
Transmission Ratio ◽  
Content Type ◽  
Oil Film ◽  
Pressure Changes ◽  
The Relationship

Purpose The purpose of this paper is to study the influences of the oil film thickness between the friction pairs, the rotational speed of the active and passive friction disks and the inlet pressure of the lubricant on the transmission efficiency. Design/methodology/approach A mathematical model of transmission efficiency was established, and the efficiency of transmission was studied by means of numerical analysis. Findings The results demonstrate that the transmission efficiency decreases with the thickness of the oil film increases. When the thickness of oil film d = 0.1 mm, the relationship between transmission efficiency and transmission ratio is linear, that is, with the transmission ratio increases, the transmission efficiency also increases which does not change with the inlet pressure changes. However, when d = 0.1 mm, their relationship is non-linear; the efficiency increases first and then decreases as the transmission ratio increases, but decreases as the inlet pressure increases. Originality/value The authors obtained a rule is that increasing the rotational speed and reducing the inlet pressure of the lubricating oil can improve the transmission efficiency. This study can provide a theoretical basis for power transmission designing of hydro-viscous clutch.

Matching the relationship between rotational speed and load-carrying capacity on high-speed and heavy-load hydrostatic thrust bearing

2018 ◽  
Vol 70 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Xiao-dong Yu ◽  
Lei Geng ◽  
Xiao-jun Zheng ◽  
Zi-xuan Wang ◽  
Xiao-gang Wu
Keyword(s):  
Carrying Capacity ◽  
Rotational Speed ◽  
Thrust Bearing ◽  
Lubricating Oil ◽  
Load Carrying Capacity ◽  
Average Pressure ◽  
Content Type ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Load Carrying

Purpose Rotational speed and load-carrying capacity are two mutual coupling factors which affect high precision and stable operation of a hydrostatic thrust bearing. The purpose of this paper is to study reasonable matching relationship between the rotational speed and the load-carrying capacity. Design/methodology/approach A mathematical model of relationship between the rotational speed and the load-carrying capacity of the hydrostatic bearing with double-rectangle recess is set up on the basis of the tribology theory and the lubrication theory, and the load and rotational speed characteristics of an oil film temperature field and a pressure field in the hydrostatic bearing are analyzed, reasonable matching relationship between the rotational speed and the load-carrying capacity is deduced and a verification experiment is conducted. Findings By increasing the rotational speed, the oil film temperature increases, the average pressure decreases and the load-carrying capacity decreases. By increasing the load-carrying capacity, the oil film temperature and the average pressure increases and the rotational speed decreases; corresponding certain reasonable matching values are available. Originality/value The load-carrying capacity can be increased and the rotational speed improved by means of reducing the friction area of the oil recess by using low-viscosity lubricating oil and adding more oil film clearance; but, the stiffness of the hydrostatic bearing decreases.

Experimental study on line-contact elastohydrodynamic grease lubrication properties of surface-textured rollers

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuqin Yang ◽  
Dexing Hu ◽  
Qianhao Xiao ◽  
Shun Zhao
Keyword(s):  
Film Thickness ◽  
Surface Texture ◽  
Inhibitory Effect ◽  
Lubricating Oil ◽  
Line Contact ◽  
Grease Lubrication ◽  
Content Type ◽  
Oil Film ◽  
Crown Width ◽  
Lubrication Properties

Purpose This paper aims to study line-contact elastohydrodynamic grease lubrication properties of surface-textured rollers as well as the effect of different crown widths (dw) on oil film thickness under textured conditions. Design/methodology/approach The laser processing method was used to make the micro-texture on the surface of GCr15 steel rollers; lithium grease was used as the lubricant, and line-contact elastohydrodynamic grease lubrication experiments under pure sliding conditions were performed on light interference elastohydrodynamic-lubricated experimental table. Findings The results show that the line-contact elastohydrodynamic grease lubrication is closely related to the textured crown width of steel rollers. At low speeds and light loads, texturing has an inevitable inhibitory effect on the formation of the lubricating oil film, and the smaller the width of the crown area, the more obvious the inhibitory effect, which is not conducive to the improvement of the lubrication condition. At high speeds and high loads, the textured roller with dw = 1 mm has the largest oil film thickness and shows better lubrication performance. Originality/value At present, there is little research on the surface texture of line-contact friction pairs. This work explores the effect of different textured crown width on the lubricating properties of line-contact elastohydrodynamic grease lubrication by experiment. It provides a new theoretical basis for the subsequent practical application of surface texture technology.

scholarly journals A Frequency Locking Method for ICPT System Based on LCC/S Compensation Topology

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2626
Author(s):  
Yansong Li ◽  
Minhao Wang ◽  
Weiwei Zhang ◽  
Mengmeng Zhao ◽  
Jun Liu
Keyword(s):  
Output Power ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Maximum Efficiency ◽  
Initial Value ◽  
Frequency Locking ◽  
Inductively Coupled ◽  
Output Characteristics ◽  
The Relationship

Aiming to maximize the transmission efficiency of inductively coupled power transmission (ICPT) system with the designed output power, a frequency locking method for an ICPT system based on LCC/S compensation topology is proposed in this paper. Firstly, the relationship between compensation component Lf1 and output power was deduced by the lossless model, and the initial value of Lf1 was obtained. Then, considering the system loss, the designed output power and frequency were input into the frequency locking program, and Lf1 and other compensation parameters were dynamically tracked. At the same time, the transmission efficiency of the system was calculated, and the frequency that achieved maximum efficiency was automatically locked when the system met the requirements of the designed output power. Finally, based on the method, the output characteristics of the system were verified by experiments.

Application of dynamic mesh technology in the oil film flow simulation for hydrostatic bearing

2019 ◽  
Vol 71 (1) ◽  
pp. 146-153
Author(s):  
Yanqin Zhang ◽  
Zhiquan Zhang ◽  
Xiangbin Kong ◽  
Rui Li ◽  
Hui Jiang
Keyword(s):  
Film Thickness ◽  
Flow Velocity ◽  
Manufacturing Industry ◽  
Dynamic Mesh ◽  
Lubricating Oil ◽  
Thickness Variation ◽  
Content Type ◽  
Oil Film ◽  
Rotating Speed ◽  
Hydrostatic Bearing

Purpose The purpose of this paper was to obtain the lubrication characteristics of heavy hydrostatic bearing in heavy equipment manufacturing industry through theoretical analysis and numerical simulation. Design/methodology/approach This paper discusses the influence of oil film thickness variation on velocity field, outlet-L and outlet-R flow velocity under the hydrostatic bearing running in no-load 0 N, load 400 KN, full load 1,500 KN and rotating speeds of 10 r/min, 20 r/min, 30 r/min, 40 r/min, 50 r/min and 60 r/min, by using dynamic mesh technology and FLUENT software. Findings When the working table rotates clockwise, in the change process of oil film thickness, the fluid flow pattern of the lubricating oil at the edge of the sealing oil is the rule of laminar flow, and the oil cavity has a vortex. The outlet-R flow velocity becomes higher and higher by increasing the bearing load and working table speed, and the flow velocity increases with the decrease in oil film thickness; the outlet-L flow velocity increases with the decrease in oil film thickness under low rotating speed (less than 10 r/min) condition and decreases with the decrease of oil film thickness under high rotating speed (more than 60 r/min) condition. Originality/value The influence of the oil film thickness on the flow state distribution of the oil film was analyzed under different working conditions, and the influence rules of oil film thickness on the flow velocity of hydrostatic bearing oil pad was obtained by using dynamic mesh technology.

Utility of gas inlet pressure monitoring in extracorporeal membrane oxygenation

2020 ◽  
pp. 039139882096212
Author(s):  
Yuki Nakamura ◽  
Takafumi Nakakita ◽  
Kazuhiko Yamamoto ◽  
Aki Kamada ◽  
Shinichi Iguchi ◽  
...  
Keyword(s):  
Gas Flow ◽  
Sodium Dodecyl ◽  
Significant Negative Correlation ◽  
Solution Concentration ◽  
Flow Path ◽  
Inlet Pressure ◽  
Plasma Leakage ◽  
Pressure Changes ◽  
The Relationship ◽  
Reduced Surface

Purpose: Purpose: Condensation that clogs the hollow fibers of the oxygenation and accumulation of plasma leaks reduces oxygenated lung capacity. In this study, artificial We evaluated whether monitoring changes in lung gas inlet pressure was a way to predict these complications. Methods: Changes in gas inlet pressure and oxygenation capacity of three different prostheses (BIOCUBE6000, EXCELUNG PRIME, and Capiox-LX) Evaluated the relationship. When simulating plasma leakage using BIOCUBE6000, sodium dodecyl sulfate (SDS) (1%, 0.1%, A solution of 0.01%, and RO water) reduced surface tension. During 120 minutes of circulation, changes in gas inlet pressure and leakage from the membrane into the gas flow path The amount of fluid was measured. Results: There was a significant negative correlation between the gas inlet pressure changes and the oxygenation capacity of all three oxygenators (BIOCUBE6000: R2 = 0.957, EXCELUNG PRIME: R2 = 0.946, Capiox-LX: R2 = 0.878). After 120 min of SDS solution circulation using the BIOCUBE6000, both the gas inlet pressure and the volume of fluid leaking from the membrane into the gas flow path increased in proportion to the SDS solution concentration: RO water (0.56 ± 0.11 mmHg and 16.67 mL ± 0.94 mL), 0.01% SDS (0.98 ± 0.11 mmHg and 23.3 ± 0.47 mL,) 0.1% SDS (1.64 ± 0.21 mmHg and 29.0 ± 1.63 mL), and 1%SDS (14.3 ± 0.27 mmHg and 36.7 ± 0.47 mL) (n = 3). Conclusion: This study confirmed that monitoring the gas inlet pressure changes of an oxygenator during ECMO is clinically useful.

Research on Transmission Efficiency of Cycloid Cam Speed Reducer

2011 ◽  
Vol 138-139 ◽  
pp. 310-314
Author(s):  
Jun Kai Yang ◽  
Yun Jie Xu
Keyword(s):  
Rotational Speed ◽  
Influence Factors ◽  
Dynamic Measurement ◽  
Transmission Efficiency ◽  
Working Process ◽  
Load Change ◽  
Speed Reducer ◽  
The Relationship

Cycloid cam speed reducer is a widely used transmission. In practice, there are many kinds influence factors which affect transmission efficiency of cycloid cam speed reducer. In this research, dynamic measurement of the transmission efficiency has carried out by experiment It mainly studies the relationship between speed, load change and transmission efficiency during cycloid cam speed reducer working process. Experiment results show that transmission efficiency of cycloid cam speed reducer could be improved by increasing the load, other methods can also use such as reducing the input rotational speed.

Effect of two-phase flow on transmission torque of oil film at high rotational speeds

2018 ◽  
Vol 70 (8) ◽  
pp. 1367-1373 ◽  
Author(s):  
Fangwei Xie ◽  
Xudong Zheng ◽  
Yaowen Tong ◽  
Bing Zhang ◽  
Xinjian Guo ◽  
...  
Keyword(s):  
Flow Regime ◽  
Rotational Speed ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Flow Region ◽  
Phase Flow ◽  
Field Variation ◽  
Two Phase ◽  
Content Type ◽  
Oil Film

Purpose The purpose of this paper is to study the working characteristics of hydro-viscous clutch at high rotational speeds and obtain the trend of flow field variation of oil film. Design/methodology/approach The FLUENT simulation model of the oil film between the friction disks is built. The effect of variation of working parameters such as input rotational speed, oil flow rate and film thickness on two-phase flow regime and transmission torque is studied by using the volume of fluid model. Findings The results show that the higher the rotational speed, the severer the cavitation is. In addition, the two-phase flow region makes the coverage of oil film over the friction pairs’ surface reduce, which results in a decrease in transmission torque for the hydro-viscous clutch. Originality/value These simulation results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for power transmission mechanism of oil film by considering the existence of a two-phase flow regime consisting of oil and air.

Influence of rotational speed of a heavy-duty hydrostatic turret on bearing performance under tilt

2019 ◽  
Vol 72 (5) ◽  
pp. 575-579
Author(s):  
Zhifeng Liu ◽  
Junyuan Guo ◽  
Yumo Wang ◽  
Dong Xiangmin ◽  
Yue Wu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Rotational Speed ◽  
Design Methodology ◽  
Reynolds Equation ◽  
Heavy Duty ◽  
Film Stability ◽  
Content Type ◽  
Oil Film ◽  
Tilt Stability ◽  
The Stability

Purpose This paper aims to propose a method for finding the maximum rotational speed of an inclined turntable at which the stability of the bearing oil film is maintained. Design/methodology/approach The finite difference method was used to solve the Reynolds equation. Variation of bearing capacity of a tilted hydrostatic turret over time was determined. The combined effect of tilt and rotational speed of the turret on the oil film stability was also analyzed. Findings When the turntable is operated at low speeds with only small angle of tilt, stability of the oil film is maintained. At lower rotational speeds, a smaller angle of tilt improves the bearing capacity and ensures stability of the oil film. Whereas, higher rotational speeds can have a considerable influence on the bearing capacity. Originality/value The results demonstrate that the inclination or tilt of the turntable significantly affects the stability of the oil film.

Oil film thickness analysis of the sealing surface for hydraulic rotary rectangular vane actuator

2018 ◽  
Vol 70 (8) ◽  
pp. 1494-1499
Author(s):  
Han Qing ◽  
LiangXi Xie ◽  
Lu Li ◽  
Chuang Jia
Keyword(s):  
Numerical Model ◽  
Film Thickness ◽  
Contact Pressure ◽  
Reynolds Equation ◽  
Distribution Curve ◽  
Contact Pressure Distribution ◽  
Content Type ◽  
Oil Film ◽  
Rotary Actuator ◽  
The Relationship

Purpose This paper aims to establish a numerical model to calculate contact pressure for rectangular vane sealing surface of hydraulic rotary actuator. Numerical model can be applied to solve the steady-state Reynolds equation after the oil film thickness and the contact pressure distribution curve of the vane sealing surface are obtained. Design/methodology/approach The authors established the numerical model of contact pressure base on the theory of elastic after, the Reynolds equation is solved by the inverse solution. Findings The relationship between the oil film thickness of vane sealing surface and the contact pressure on different sealing location for hydraulic rotary actuator is obtained. At the same time, the lubrication state on the surface of seal is also found when the hydraulic rotary actuator runs stably. Originality/value The study shows that the lubricating state of the vane sealing surface is mixed lubrication, when the rotor of the hydraulic rotary actuator is running stably at a certain speed. Meanwhile, this research will provide a theory basis for later experiment for the hydraulic rotary vane actuator.

scholarly journals The Effects of Shear Stress on the Lubrication Performances of Oil Film of Large-Scale Mill Bearing

2009 ◽  
Vol 76-78 ◽  
pp. 713-718
Author(s):  
Jian Mei Wang ◽  
Qing Xue Huang ◽  
Zheng Yi Jiang ◽  
Kiet Tieu
Keyword(s):  
Shear Stress ◽  
Large Scale ◽  
Film Flow ◽  
Lubricating Oil ◽  
Oil Film ◽  
Lubrication Performance ◽  
Shear Performance ◽  
Contact Surfaces ◽  
The Relationship ◽  
Bearing System

A new coupling numerical algorithm has been developed to integrate Finite Difference Method (FDM) with Boundary Element Method (BEM) to analyze shear performance of oil film by iteratively solving a series of equations such as the film flow velocity and shear stress equations for contact bodies in bearing system. With consideration of the variations of viscosity and density with pressure and temperature, the effects of shear stress of oil film layers on lubrication performance of contact surfaces under different loadcases were discussed. Moreover, Germany-made Anton Paar MRD (Magnetic Rheologic Device) was used to determine the relationship between the viscosity and shear stress of lubricating oil. The conclusions were verified to be beneficial to the further study on lubricating performance of heavy contact components and to prolong their service lives.

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