Research of resistance forces in the contact zone between the seal and the floor of a mobile robotic air cushion platform

Abstract Treadwear is explained by specific mechanical properties and actions of tires. Rubber shear stresses in the contact zone between the tire and the road become large at large slip angles. When normal stresses are insufficient to prevent sliding at the rear of the footprint, wear occurs at a rate that depends on test severity. Two experimental approaches are described to relate treadwear to tire characteristics. The first uses transducers imbedded in a simulated road surface to obtain direct measurements of contact stresses on the loaded, freely-rolling, steered tires. The second approach is developed with the aid of a simple carcass, tread-band, tread-rubber tire model. Various tire structural configurations; characterized by carcass spring rate, edgewise flexural band stiffness, and tread rubber shear stiffness; are simulated and lateral shear stress response in the contact zone is determined. Tires featuring high band stiffness and low carcass stiffness generate lower lateral shear stress levels. Furthermore, coupling of tread-rubber stiffness and band flexural rigidity are important in determining level of shear stresses. Laboratory measurements with the described apparatus produced values of tread-band bending and carcass lateral stiffness for several tire constructions. Good correlation is shown between treadwear and a broad range of tire stiffness and test course severities.

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Stibnite vein from Dębowina near Bardo (polish Sudetes)

Contemporary Trends in Geoscience ◽

10.2478/ctg-2014-0004 ◽

2013 ◽

Vol 2 (1) ◽

pp. 28-33

Author(s):

Piotr Kotula

Keyword(s):

Contact Zone

Abstract In the contact zone of the Bardo Structure and Kłodzko-Złoty Stok Intrusion and Kłodzko Metamorphic, metasomatic orebearing quartz-carbonate veins rich in Sb, Zn, Cu, Ag, Au, Pb are present. In 1771 the mine ,,Reiche Silber Gluck” within stibnite vein was founded in Dębowina near Bardo. Its entrance was discovered again in 2007. The stibnite vein is mainly build of stibnite and sphalerite and of quartz and dolomite rich in Mn. Stibnite crystallizes as columnar or forming radiate centres and aciculars. Its crystals reach size to 2 mm. Sphalerite appears as individual anhedral and polymineralic grained concentrations reaching size to 2,5 mm. Earlier pyrite and arsenopyrite crystallized - they occur locally in this deposit. There were found also in the deposit tetrahedrite rich in Ag, what wasn't reported earlier in studies from the mine in Dębowina.

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IMPROVEMENT OF THE HYDRAULIC EXCAVATOR BUCKET DESIGN

The Russian Automobile and Highway Industry Journal ◽

10.26518/2071-7296-2019-3-202-213 ◽

2019 ◽

Vol 16 (3) ◽

pp. 202-213 ◽

Cited By ~ 1

Author(s):

G. G. Buriy ◽

V. S. Shherbakov ◽

S. B. Skobelev ◽

V. F. Kovalevskiy

Keyword(s):

Cost Reduction ◽

Production Costs ◽

Hydraulic Excavator ◽

Engineering Structures ◽

Excavator Bucket ◽

Productivity Increase ◽

Hydraulic Excavators ◽

Reducing Costs ◽

Rational Operation ◽

Resistance Forces

Introduction.Construction of engineering structures is impossible without building and road machines. The large volume of financing is allocated for such machines’ purchase. The main ways of reducing costs of the equipment consist in more rational operation of the equipment and also in decrease of equipment’s cost by constructive changes. The paper demonstrates the new design of the single-bucket hydraulic excavator with smaller cost.Materials and methods.The main ways of cost reduction for construction machines are more rational operation and depreciation of a design with the required characteristics’ maintaining. The paper describes constructive changes of the working equipment of the single-bucket hydraulic excavator, which allow decreasing the production costs.Results.The authors describe the new bucket design of the single-bucket hydraulic excavator. Moreover, the authors carry out the analysis of the existing buckets’ design. The paper also illustrates the functioning on bucket forces while digging process. The authors describe the solutions of the problem for productivity increase of the single-bucket in hydraulic excavators. In addition, the authors make the scheme of the bucket loading while digging process. Such scheme helps to reduce resistance forces of digging.Discussion and conclusions.As a result, the paper presents the design of the working equipment of the hydraulic excavator’s single-bucket, which allows reducing resistance forces of digging. Such results would help to establish buckets of bigger capacity and would lead to the productivity increase.

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