Bucket Teeth Research Articles

Experimental puncture loads for external interference of pipelines by excavator equipment

A series of puncture experiments is presented for penetration of steel pipelines by excavator bucket teeth. Static puncture forces are obtained for pipes of 4.8–6.9 mm wall thickness, for a variety of different tooth geometries; primarily small cross-section or sharp tooth types have been used. Experimental results for varying tooth orientations are also presented. The results are compared against finite element simulations of the problem and against previously derived puncture relationships. The experiments provide good verification for the use of a simple puncture force equation that can be used for pipeline risk assessment purposes.

Substantiation of the Capacity of Percussion Devices and Estimation of the Performance Capabilities for the Active Bucket Excavator EKG-5V

The maximum capacities recommended for percussion devices for drive of the active bucket teeth are substantiated. A procedure is proposed for the predictive estimation of the active bucket excavator performance.

Denting of pressurised pipelines under localised radial loading

This paper examines quasi-static denting of buried pipelines under lateral loading from excavator machinery fitted with rectangular cross-section bucket teeth. A semi-analytical solution for the load-deflection response under this loading case is presented. Finite-deflection limit analysis is used to describe the plastic behaviour, while standard elastic shell theory is used to describe the elastic response of a pipeline. When calibrated against numerical results, the combination of these two analytical methods enables the entire load deflection history of a pipeline indentation to be described. This method is verified by comparison with finite element results and with experiment. For the range of geometries examined here, the accuracy of the analytical procedure exceeds that of currently available methods.

Digging control system for hydraulic excavator

The hydraulic excavator is used at a wide variety of sites. Its diversity and convenient operating nature make it popular. Among the different types of work performed by hydraulic excavators, level digging work accounts for a large percentage. When digging or finishing ground surfaces level using the backhoe front attachment, the boom tip height must be controlled so that the bucket tooth tip can be moved horizontally. This paper describes a method of automated level digging control we wish to propose. By using this control system, depth controlled digging can be achieved in the same way as usual manual lever operation while minimizing repetitive depth confirmation work, thereby raising the working efficiency level.

Prediction of gouging abrasion resistance of steel by pendulum grooving and other laboratory test methods

A comparative investigation is made of different laboratory test methods with respect to their ability to guide in the selection of materials resistant to gouging abrasive wear. The evaluation is based on the wear of excavator bucket teeth during loading of wet blast stone. Five different steel grades were included, ranging from quenched and tempered carbon steel to tool steel. The specific energy consumption during single-pass pendulum grooving proved to give the best correlation with the field test. It was also found that the pendulum test produced friction layers typical of gouging abrasion. Among the test materials a 5.3 wt.% Cr tool steel proved to have the best wear resistance followed by a quenched and tempered carbon steel grade.

Bucket wheel excavator performances at Neyveli Lignite Mine

Bucket-wheel excavators have been in use at the Neyveli Lignite Mine in the State of Tamil Nadu, India, since the early nineteen-sixties. The mining environment has been particularly harsh for BWE application. The adverse influencing factors are the hardness of the overburden formation, high abrasivity of rock and artesian ground water conditions. In this paper, the performances of the BWEs at Neyveli have been statistically analysed to determine the effects of physico-mechanical properties of overburden, blasting and rainfall on machine productivity, availability, wear-and-tear of bucket teeth, power consumption, production efficiency and cost of mining. An empirical relationship between the production efficiency, defined as the ratio of actual production rate to the theoretical one, and the bench height and width, height of slices, specific cutting resistance of the overburden material and its clay content, consumption of explosives, and conveyor length has been established.

Bearings for aircraft hydraulic pumps : W. S. Bobier, Jr. and C. R. Potter. Applied hydraulics, v. II. May 1958, p. 108–110

The hydraulic excavator is used at a wide variety of sites. Its diversity and convenient operating nature make it popular. Among the different types of work performed by hydraulic excavators, level digging work accounts for a large percentage. When digging or finishing ground surfaces level using the backhoe front attachment, the boom tip height must be controlled so that the bucket tooth tip can be moved horizontally. This paper describes a method of automated level digging control we wish to propose. By using this control system, depth controlled digging can be achieved in the same way as usual manual lever operation while minimizing repetitive depth confirmation work, thereby raising the working efficiency level.