Experimental and theoretical study of dynamic characteristics of Bernoulli gripper

Shi, Kaige; Li, Xin

doi:10.1016/j.precisioneng.2018.01.006

Cited by 28 publications

(13 citation statements)

References 12 publications

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“…The process of the pressure decreasing to P d is neglected because region 2 is small 30 . The pressure gradient in the r ‐direction in region 2 with the coupling effect of inertial and viscous forces can be expressed as follows 32 :

\frac{dP}{dR} goodbreak= goodbreak- \int_{0}^{h} italicρu \frac{du}{dR} italicdX \cdot \frac{1}{h / 2} goodbreak+ τ \cdot \frac{1}{h / 2}

The viscous stress is defined as follows:

τ = \int_{0}^{h / 2} μ \frac{\partial^{2} u}{\partial z^{2}} italicdX

The air velocity distribution in the film thickness direction is expressed as follows 33 :

\frac{u}{\overset{true¯}{u}} goodbreak= \frac{3}{2} ([], 1 goodbreak- {(\frac{X}{h / 2})}^{2})

Combining Equations ()‑(), the pressure gradient in the r ‐direction can be described as follows:

\frac{dP}{dR} goodbreak= \frac{3 R_{con} T {\dot{m}}^{2}}{10 π^{2} R^{2} h^{2} P} ((), \frac{1}{R} goodbreak+ \frac{1}{P} \frac{dP}{dR}) goodbreak- \frac{6 μ R_{con} T \overset{m}{true}}{π {RPh}^{3}}

where R con is the gas constant, T is the temperature,

\overset{m}{true}

is the supply mass flow rate.…”

Section: Numerical Modellingmentioning

confidence: 99%

Novelfull‐regionmodel of inherent orifice aerostatic bearings considering air flow in orifice and clearance

Zhang

Wang

et al. 2022

Lubrication Science

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The performance of inherent orifice‐restricted aerostatic bearings (IORABs) is directly determined by the coupling of air flow in the orifice and clearance. This paper presents a novel full‐region model to analyse the performance of IORABs. The air flowing in the orifice is treated to be adiabatic. The air flow in the pressure depression region of the clearance, which is the key factor influencing the bearing performance, including inertial and viscous terms, is modelled. The Reynolds equation is used to simulate the air flow in the laminar flow region of the clearance. By using this model, the pressure distribution, including the pressure depression characteristics, could be accurately predicted and achieved substantial agreement with the experimental results. The predicted load capacity is accorded well with the published experimental data without relying on the discharge coefficients. The airflow characteristics in the orifice are crucial in determining the bearing performance and directly influenced by the orifice inner surface shape (OISS). Therefore, the pressure distribution and the static characteristics of the bearings with coupling different OISS are also systematically analysed by using this model. Narrowing and widening OISS influence the pressure depression region and the pressure value of the turning point to directly influence the static characteristics of the bearings. The full‐region model and the results are significantly for guiding the precisely calculating and designing the IORABs.

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\frac{dP}{dR} goodbreak= goodbreak- \int_{0}^{h} italicρu \frac{du}{dR} italicdX \cdot \frac{1}{h / 2} goodbreak+ τ \cdot \frac{1}{h / 2}

The viscous stress is defined as follows:

τ = \int_{0}^{h / 2} μ \frac{\partial^{2} u}{\partial z^{2}} italicdX

The air velocity distribution in the film thickness direction is expressed as follows 33 :

\frac{u}{\overset{true¯}{u}} goodbreak= \frac{3}{2} ([], 1 goodbreak- {(\frac{X}{h / 2})}^{2})

Combining Equations ()‑(), the pressure gradient in the r ‐direction can be described as follows:

\frac{dP}{dR} goodbreak= \frac{3 R_{con} T {\dot{m}}^{2}}{10 π^{2} R^{2} h^{2} P} ((), \frac{1}{R} goodbreak+ \frac{1}{P} \frac{dP}{dR}) goodbreak- \frac{6 μ R_{con} T \overset{m}{true}}{π {RPh}^{3}}

where R con is the gas constant, T is the temperature,

\overset{m}{true}

is the supply mass flow rate.…”

Section: Numerical Modellingmentioning

confidence: 99%

Novelfull‐regionmodel of inherent orifice aerostatic bearings considering air flow in orifice and clearance

Zhang

Wang

et al. 2022

Lubrication Science

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“…This adsorption force is caused by vacuum pressure, which also exits the vacuum penetration effect. In addition, some other researchers developed some noncontact chucks based on the Bernoulli effect [12][13][14][15] and vortex blades. 16,17 Both types of chucks are noncontact and used in occasions where the workpiece cannot be directly contacted.…”

Section: Recent Label Separation Researchmentioning

confidence: 99%

Airflow‐induced high‐speed separation method for stacked paper labels and its mechanism

Huang

et al. 2020

Packag Technol Sci

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An airflow‐induced separation method for stacked paper labels is proposed with a stream of compressed air used to jet vertically onto the side of the stacked labels and force constraints applied to the two ends of the labels. Its mechanism is revealed that the viscous force caused by airflow is the main driving force for the initial separation of labels and the vertical force is the main factor for the formation of successive separation channels. Theoretical and experimental analyses are implemented to ensure the effects of airflow velocity, label characteristics, label stress, and other factors on label separation and show that a stable separation gap can be generated with separation efficiency of more than 3600 sheets per minute and reliability of 99.99%. A complete airflow‐induced label separation device is designed, which can be integrated into the existing packaging machine, and the physical feasibility of the stack label separation method is verified by experiments.

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“…Then, the relationship between the outer diameter and the lifting force and that between the gap height and the lifting force are discussed, based on which a method for finding the optimal outer diameter is presented. In paper by Shi and Li (2018) study experimentally and theoretically investigates the dynamic characteristics of the BGD.…”

Section: Introductionmentioning

confidence: 99%

Gripping Devices of Industrial Robots for Manipulating Offset Dish Antenna Billets and Controlling Their Shape

et al. 2021

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Invention proposes an adaptive gripping device of an industrial robot, which combines functions of capturing different-shape manipulation objects with control of deviations from the shape of these objects. The device is a T-shaped frame with three Bernoulli grips pivotally mounted thereon and a pneumatic sensor. Analytical dependencies are presented for determination of design parameters of adaptive gripping device and calculation of required lifting force of each of Bernoulli Gripping Device (BGD). Formula is derived for determining its position of pneumatic sensor on frame of gripping devices. In the ANSYS-CFX software environment, numerical simulation of airflow dynamics in the gap between the cooperating BGD surfaces and the offset mirror antenna plate blank. The simulation was based on the Reynolds-Averaged Navier–Stokes (RANS) equations of viscous gas dynamics, the Shear Stress Transport (SST) model of turbulence, and the y model of laminar–turbulent transition. As a result of the simulation, the effect of the curvature radius of the surface of the plates of offset mirror antennas on the BGD power characteristics was determined.

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Experimental and theoretical study of dynamic characteristics of Bernoulli gripper

Cited by 28 publications

References 12 publications

Novelfull‐regionmodel of inherent orifice aerostatic bearings considering air flow in orifice and clearance

Novelfull‐regionmodel of inherent orifice aerostatic bearings considering air flow in orifice and clearance

Airflow‐induced high‐speed separation method for stacked paper labels and its mechanism

Gripping Devices of Industrial Robots for Manipulating Offset Dish Antenna Billets and Controlling Their Shape

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