DE1923282A1 - Device for sealing drilling motor shafts - Google Patents

Description

Pafenfanwälfe

? ELLENI! N υ. LUYKEN

8000 Munich 22

Zweibrückenfr. 6th

Specialnoje Konstruktorskoje byuro 7, May 1969

ρ ο elektroburenijiiy

Moscow / USSR ^{P 24}

DEVICE FOR Abdichi ¹ EN OF BOHRMOTORWBLLEN

The invention relates to devices for sealing drilling motor shafts, in particular electric (electric drills) and hydraulic (turbine drill) drilling motors.

It is currently used to hermetically seal Electric drill shafts with a largely known device Housing which forms an annular space with the shaft, which is separated by a face seal into a high-pressure chamber and a low-pressure chamber separate and suitable for operation at a maximum pressure of 15 kp / cm is.

With the recent strong growth in the use of hydromonitor drill bits, which under certain conditions ensure a considerable increase in drilling speed and a 2 to J-fold reduction in drill bit oil consumption per borehole, the pressure on the stuffing box of a drill motor reaches 80 to 100 kp / cm ² .

It is known that when working under such a high

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Hydraulic pressure relief seals can also be used.

The known end seals used for high pressures, however, work unsatisfactorily in the case of strong pressure fluctuations in the flushing fluid and strong vibrations to which the electric drills are exposed in a borehole because they are quickly etched away or an opening ^{11 of} their sealing end pairs occurs .

The aim of the present invention is to provide one Device for sealing drilling motor shafts, which makes it possible to hermetically seal the rotating shafts at large pressure gradients with a high safety factor.

This object is achieved in that in the device for sealing motor shafts, which have a housing, which forms an annular space with the shaft, which is separated into a high-pressure and a low-pressure space by a face seal, According to the invention in the annular space on the part of the low-pressure space still an end seal is attached such that between this and the first seal forms a chamber in which a plunger pump is set up, which is used for pumping back from the High pressure chamber is intended in the oil leaked chamber back into the high pressure chamber.

A "floating" annular piston is expediently placed in the chamber between the pump and the seal of the high pressure chamber arranged, which opens the suction valve of the pump when the pressure is reduced in the chamber and the seal of the high pressure chamber at Pressure increase in the chamber against the pressure of the low-pressure space compresses.

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It is also useful to have the plunger pump driven by the shaft of the drilling motor with the aid of a swash plate.

By employing the present invention, the drilling effectiveness of hydromonitor drill bits will increase, as will the The operating time of drilling molors has been greatly extended between viewing.

The invention is based on an exemplary embodiment below Be explained in more detail with reference to an accompanying drawing. The drawing represents a longitudinal section through the device for sealing drilling motor shafts according to the invention.

The overpressure in room 1 of about 100 kp / cm is taken up directly by the hydraulically relieved face seal 2 The oil that has seeped through this seal passes through channel 3 into chamber 4, which is from the low-pressure chamber 5 is separated by a second, additional end seal 6 and the annular piston 7; the one located above the annular piston 7 Space 8 is connected to the low-pressure space 5 by channel 9.

The oil that has seeped through the seal 2 from the high pressure chamber 1 is transferred from the chamber 4 into the high pressure chamber 1 by means of a plunger pump 10 pumped back, which consists of plunger 11, spring 12, suction valve 13 and pressure valve 14.

The pump 10 is driven by the shaft 15 by means of a swash plate 16 which is attached to this shaft of the drilling motor is.

The device is delimited on the outside by the housing 17 and on the inside by the shaft 15.

When pumping back oil from the chamber 4- the pressure is opposite the pressure in space 5 is reduced and the annular piston 7 moves downward, being attached to it with a

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Pin 18 opens the suction valve 1.5 a little. This starts the Pump to work "empty", and the oil supply from the chamber into the high pressure chamber ceases. When setting oil return tion by the pump, the ring piston is pushed upwards by oil, which enters through the face seal 2. A slight upward stroke of the annular piston ends with a new one Return of oil by the pump 10, after which the annular piston 7 goes down again.

In this way, the annular piston 7 performs oscillating movements, in which the pump 10 soon removes the oil from the chamber 4- pumped back into the high pressure chamber 1, soon it will be empty

At «4öea normal operation of the relieved face seal 2 is the oil flow from the high pressure chamber 1 to the chamber 4 is insignificant. However, it can happen that this face seal suddenly "opens". This may be due to a strong vibration of the device as a result of a change in the contact pressure distribution in the Butt joint of the front seal pair 2 happen. If the seal 2 has "opened", the oil quickly enters the chamber Λ and the piston is ejected upwards. At the beginning of the upward movement of the annular piston 7, the pump 10 begins pumping oil into the high pressure chamber 1 while in the upper end position the annular piston 7 presses the opened pair of front seals 2 together. As a result, the normal work becomes this Seal restored.

en
The pressure remains in all working positions of the device

in the chamber 4- compared to that of the low-pressure chamber 5 low (During the tests it was no more than 5 kgf / cm).

The pressure gradient on the second / side, which is always kept low Front seal 6 ensures stable operation of the same and minimal oil passage to the low-pressure chamber.

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The present invention was carried out on a test bench at

2 rather

a pressure gradient of 100 kp / cm tested. During the operating time of 200 hours, the oil pressure remained very low (below

3
20 cnr oil per working day). After dismantling and inspecting individual parts, only weak familiarization areas were found. Thus, the device according to the invention can be considered effective enough.

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Claims (3)

PotüntoiiwoKe ZELLENiIN and LUYKEN OÜÜO Munich 22 ~ 6 "7- May 1969 Zwtlbrjckerwfr, 4 · ρ 24- 4-56 PATENT CLAIMS Λ" 1. Device for sealing drilling motor shafts, which has a housing which forms with the nVelle a Hingraum, the through a face seal in a high pressure and a Low pressure chamber is separated, characterized that in the annular space on the part of the low-pressure space (5) a second end seal (6) is attached in such a way that between this and the first seal (2) forms a chamber (4) in which a plunger pump (10) is set up, which for Pumping back the oil that has seeped from the high pressure chamber (1) into the chamber (4) back into the high pressure chamber (1) is determined is. 2. Apparatus according to claim 1, characterized in that in the Ka m mer (4) a "floating" between the pump (10) and the seal (2) of the high pressure chamber (1) housed ring piston (7) is arranged, which the suction valve (13) of the pump (10) when the pressure is reduced in the Chamber (4) opens and the seal (2) of the high pressure chamber (1) when the pressure in the chamber increases compared to the pressure in the low-pressure chamber (5) compresses. 3. Device according to claim 1 and 2, characterized in that that the plunger pump (10) is driven by the shaft (15) of the drilling motor with the aid of a swash plate (16) will. 909883/0377