ON THE DEVELOPMENT OF A HYDRAULIC-DRIVE ROTARY DRILLING MACHINE FOR OPEN-PIT OPERATIONS

O. D. Alimov, I. G. Basov, V. F. Gorbunov

At present, in mining practice and in construction, electric drills and pneumatic drilling hammers have found wide application for drilling blast holes. These machines are produced in series and, in terms of their qualities, generally satisfy mining enterprises when there are substantial volumes of drilling work. For the operation of such machines, electrical or pneumatic power must be supplied to the drilling site, which usually requires considerable capital expenditures. They are quite natural and, of course, justify themselves when there is a large volume of drilling work concentrated in one place.

But in a number of cases drilling work has to be carried out at scattered sites, remote from one another, and at frequently changing workplaces—for example, in geological exploration work, in construction, in open-pit mining when drilling oversize blocks, etc.

In this case, supplying electrical or pneumatic power to the workplace of the drilling machine takes considerably more time than the drilling process itself and entails high overhead costs.

For these purposes it is most expedient to have mobile drilling installations driven by an internal-combustion engine either directly or through intermediate pneumatic, electrical, or hydraulic systems. The wide use is known of mobile compressors driven by an internal-combustion engine for supplying drilling hammers with compressed air when drilling hard rocks. But for the excavation of soft and medium-hard rocks, where rotary drilling is used primarily, at present there are no easily movable drilling installations.

both in terms of transportation and in terms of supplying them with energy. Such machines are required in the practice of drilling operations, and they must be developed. This problem can be solved most simply and quickly by creating, for these purposes, a rotary drilling machine with a hydraulic drive both for the rotator and for the feeder. For maneuverability, such a drilling machine can be mounted on a tractor adapted for mounted implements, for example a “Belarus,” and supplied from its hydraulic system.

Fig. 1 shows a diagram of such an installation. The drilling machine is mounted on the boom of an E-153 excavator and, with the aid of hydraulic cylinders, can assume the various positions required for drilling horizontal, inclined, and

Fig. 1. Layout of installing the drilling machine on the boom of an E-153 excavator.

vertical blastholes. The rotator, consisting of a hydraulic motor and a reducer, is mounted on guides and moves along them with the aid of a feed mechanism. The drill is fastened in the spindle and is held by a cradle in the required direction during collaring and drilling. The cylinder of the guiding frame serves for preliminary positioning of the drilling unit at the place where the blasthole is to be drilled and for carrying out a certain amount of thrust, which also facilitates collaring and subsequent drilling.

As the feed device there may be used either a screw feeder driven by a plunger-type hydraulic motor, or a piston-type feeder with a chain travel doubler (Fig. 2). Such feeders were designed by the staff of the Department of Mining Machines and Mine Transport of the Tomsk Polytechnic Institute for long-travel electric drills and drilling hammers; they were tested and showed good results [1–2].

The supply of the hydraulic motors of the rotator and the feeder must be provided from the same hydraulic system as the supply of the jackhammers when the tractor is operating as an earthmoving machine.

Thus, the proposed drilling equipment is envisaged as an additional set for the series of mounted implements of the universal earthmoving machine built on the basis of the “Belarus” tractor. It can be removed at any moment, and the machine can be used as a tractor, grader, or excavator.

In terms of power, the hydraulic drive of the “Belarus” tractor, when using plunger-type axial pumps of the NPA-64 type as hydraulic motors,

Fig. 2. Schematic diagrams of feeding devices:
a—screw type; b—piston type with a chain stroke doubler.

allows the rotator power of the drilling machine to be within the range of 6–10 hp, which will make it possible not only to drill blast holes at high speed, but also to use such rigs for drilling vertical and inclined boreholes.

REFERENCES

1. O. D. Alimov. Directions in the creation of high-productivity machines for rotary drilling of blast holes. Izvestiya TPI, vol. 106, Metallurgizdat, 1958.

2. O. D. Alimov, P. A. Samoilov. Some results of testing experimental models of feeders. Article in the present collection.