FR2503584A1 - CENTRIFUGE FOR THE PURIFICATION OF MOTOR FLUIDS OF HYDRAULIC SYSTEMS - Google Patents

Abstract

THE INVENTION CONCERNS THE PURIFICATION OF LIQUIDS BY CENTRIFUGATION. THE CENTRIFUGE WHICH IS THE OBJECT OF THE INVENTION IS OF THE TYPE IN WHICH THE HUB 6 CARRYING A DRUM 5 IS MOUNTED ON A VERTICAL HOLLOW AXLE 2 WITH SLOTS 11 ARRANGED TANGENTIALLY FOR THE FORCED DELIVERY OF THE LIQUID TO BE PURED INTO THE DRUM 5 THROUGH OPENINGS 12 MADE IN THE HUB 6 AND ARRANGED IN FRONT OF THESE SLOTS 11 AND THE ORIFICES 13 TANGENTIALLY PRACTICED IN THE HUB 6 FOR THE DRAIN OF THE CLEAN LIQUID, AND IS CHARACTERIZED IN THAT IT INCLUDES A PERFORATED CYLINDER 21 WITH A THIN WALL HOUSED INSIDE THE DRUM 5 CONCENTRICALLY THEREIN, PART 23 OF CYLINDER 21 LOCATED IN THE LOWER PART OF SAID DRUM IN FRONT OF SLOTS 11 OF AXIS 2 BEING A FULL WALL. THE INVENTION MAY BE USED IN HYDRAULIC SYSTEMS OF MOBILE MACHINES, IN LUBRICATION SYSTEMS OF EXPLOSION ENGINES.

Description

I

  The present invention relates to

  supply of the driving liquids of the hydraulic controls and lubricating liquids of the lubricating circuits of machines and equipment, and particularly relates to a centrifuge for the purification of liquids

engines of hydraulic systems.

  The centrifuge for the purification of the engine fluids of the hydraulic systems, which is the subject of the invention, can be used in the hydraulic systems of mobile machines, in the lubrication systems of internal combustion engines and in the fuel supply systems. ,, as well as in technological processes for the purification of oils and fuels containing

solid impurities.

  The service life and reliability of the modern machines

  machine tools, presses and other

  Hydraulic control systems depend to a large extent on the cleanliness of the engine fluids of hydraulic systems, lubricating oils and fuels. As a result, the creation of devices to meet the requirements becoming more

  more severe, with regard to the cleanliness of

  working people, is at present of great importance. This problem becomes particularly urgent because of the continuing tendency to increase the pressure of

  operation of hydraulic systems.

  At present, the driving liquids of the

  hydraulics are purified with the help of filters

  of various types with interchangeable filter elements

  paper, wire cloth or other material, using devices using force fields

  (gravitic, magnetic, electrostatic, centrifugal).

  Impurities forming in working liquids

  During the use of the hydraulic components, mainly consist of particles of metals and quartz. Modern hydraulic systems use hydraulic accessories designed for pressures equal to more than 20 MPa and in which the clearances between the conjugated elements are 10 to 25 microns. Devices for the purification of motor fluids must therefore be capable of retaining an active way of particles of metals and quartz of a magnitude

greater than 10 microns.

  It is known that the use of

  to retain particles of a size from 10 to 15

  microns is extremely difficult because of the increase in

  the cost of the filters and their operating expenses.

  tation resulting from the reduction in the service life and the dirt retention capacity of the filter element. That is why we are currently resorting, on an ever-increasing scale, to centrifugal purifiers

  centrifuges for the purification of working liquids

  in hydraulic systems, food systems

  These centrifuges are capable of providing virtually any desired degree of cleanliness of the liquid, while being of relatively simple construction and

inexpensive maintenance.

  The objectives and specific areas of

  the use of centrifuges in hydrau-

  instead of filters or associated with them have

  the peculiarities of their realization, especially as regards their training ensured directly by the current of the liquid to be purified which is essentially

  a suspension of a very low concentration.

  We know about an oil purification centrifuge

  of the West Company's internal combustion engines

  German Mann und Hummel (See the patent of R.F.A.

  No. 1,123,625, cl.82 B 7, made public on August 10, 1962).

  The centrifuge comprises a base with an enve-

  loppe, a hollow fixed vertical axis through which the liquid to be purified arrives inside a rotating drum, mounted

  on the axle by means of bearings. The drum is

  rotated by an integrated Segner wheel-type hydraulic motor arranged in a separate chamber under

the drum.

  This centrifuge is of a large size and requires for its manufacture a large amount of metal because of the chamber used to ensure the free flow of fluid from the nozzles of the hydraulic motor and to collect drainage leaks of the liquid to be purified, in addition, the engine liquid emerging from the nozzles of

  Segner's wheel absorbs air, which

  pumps and other system accessories.

hydraulic systems.

  Another centrifuge is also known for purifying

  the lubricating oil of internal combustion engines, comprising a casing base and a hollow fixed axle

  vertical line through which the liquid to be purified arrives at

  a rotary drum mounted on the shaft by means of bearings (see Czechoslovakia Patent No. 101613,

  Cl. 46C, 14 published on 15.09.1961).

  In this centrifuge, a drum with a hub is rotated also by means of a built-in Segner wheel-type hydraulic motor with nozzles and arranged in an isolated chamber above the hub.

drum of the centrifuge.

  In order for the liquid emerging from the nozzles not to spread over the rotating drum, a

  screen. The inlet openings of the motor liquid practically

  in the drum hub are protected by a baffle which prevents impurities from being

  of the inner surface of the drum.

  The disadvantages of the known centrifuge reside in that the engine liquid is saturated with air and that it is bulky and requires for its manufacture

  a large amount of metal because of the chamber

  closing the nozzles of the hydraulic motor, while the deflector preventing the removal of impurities from the inner surface of the drum has the effect of increasing

  the power absorbed by the centrifuge.

  In addition, there is known a centrifuge for cleaning the engine liquid comprising a base with a casing, a fixed hollow vertical shaft mounted on the base and on which is mounted by means of bearings a hub carrying a drum, tubes for the supply of the liquid to be purified inside the axis and the evacuation of the liquid

  cleaned in the drum, this centrifuge being considered

  as the closest to the one that is the object of the present invention (see the article by G.A. Smirnov et al., "New centrifuge for the purification of oil", editions of ZNIITEtraktoroselkhozmache, rendered

public in 1972, pages 35 to 42).

  In the lower part of the hub wall of this known centrifuge are made openings

  arranged radially and in front of which are available

  openings made tangentially in the axis and used to bring the liquid to be purified inside the drum, while in the upper part of the hub are made tangentially arranged openings and used to evacuate the purified liquid of the pregnant

drum.

  The kinetic energy of the liquid passing through the openings

  tures of the axis and through the openings

  dials and tangential hub causes rotation of the hub with the drum. Under the effect of the centrifugal forces acting inside the drum, the solid particles

  separates from the liquid to be purified and settles on the surface.

  inner side of the drum. In the known centrifuge,

  the hydraulic motor is arranged in the drum itself

  even the centrifuge, which reduces its size and avoid air saturation of the liquid

  engine that is not in contact with the air.

  However, due to the high flow speeds

  liquid through the tangential openings of the axis, necessary to obtain a rotational speed

  sufficiently high drum, the impurities are

  the inner wall of the drum, during start-up and operation of the centrifuge, this

  which lowers the quality of the purification of the liquid.

  It was therefore proposed to develop a

  a fugitive for the purification of the hydraulic fluid of the hydraulic systems, which would make it possible to avoid the impurities being driven from the inner surface of the drum, which would allow in the end to improve the quality

  the cleaning of the engine liquid in general.

  This problem is solved using a centrifuge

  for the purification of motor fluids from hydrau-

  of the type comprising a hub carrying a drum enclosed in an envelope and mounted by means of bearings

  on a vertical hollow axis fixed in the base of the centrifugal

  slider and provided with slots arranged tangentially for the forced feeding of the liquid to be purified into the drum through openings provided in the hub and arranged

  in front of these slots and tangential orifices

  in the hub and intended for the exit of the liquid

  characterized in that according to the invention it is provided with a thin-walled perforated cylinder housed in the drum concentrically with respect thereto, that part of the wall of the cylinder which is located in its lower part, in front of the slots of the axis,

being without perforations.

  Thanks to this embodiment of the centrifuge, the jets of engine liquid to be purified arriving in the

  drum cavity are directed to the non-perforated

  from the wall of the cylinder and, by coming up against this part, lose their speed, which prevents the

  impurities deposited on the inner surface of the drum.

  This is due to the non-established operating conditions of the centrifuge (during start-up, for example) and the unstable flow of the liquid to be purified. In addition, in such an embodiment,

  removes additional energy expenses.

  It is preferable that the slots arranged tangen-

  actually in the axis of the centrifuge, in front of the

  the imperforate part of the cylinder, have side walls

  formed by a logarithmic spiral and that the tangential holes in the hub are

  made in the form of a convergent.

  The fact that the walls of the tangential slits of

  the axis are spiral logarithmic allows communication

  quer to liquid stream to purify a larger component

  Tangential health of speed for a weaker

  radial velocity, which reduces hydraulic losses.

  due to the shock of the liquid stream to be purified during

  its entry into the openings of the drum hub.

  In addition, this embodiment of the slots of the axis of the centrifuge, while ensuring a sufficiently high rotational speed of the drum, makes it possible to reduce the radial velocities of the jets of liquid to be purified entering the drum cavity, and of decrease the abduction of

  impurities deposited on the inner wall of the drum.

  The orifices made tangentially in the hub of the drum and made in the form of a convergent can reduce the speed of entry of the current into these orifices and therefore the hydraulic losses in

this part of the centrifuge.

  In this way, this embodiment of the slots in the hub axle and orifices makes it possible to reduce the hydraulic losses and, ultimately, the energy costs for rotating the drum of the centrifuge, as well as to ensure a high quality

the cleaning of the engine liquid.

  The invention will be better understood and other purposes, details and advantages thereof will appear better at

  the light of the explanatory description that will follow

  various embodiments given solely by way of nonlimiting examples, with references to the appended nonlimiting drawings in which: - Figure 1 shows schematically, in section, an overview of the centrifuge for the purification of the liquid engine d a hydraulic system, according to the invention; - Figure 2 is a sectional view along II-II of Figure 1, according to the invention; FIG. 3 is a sectional view along III-III of FIG.

Figure 1, according to the invention.

  The centrifuge for the purification of the driving liquids of the hydraulic systems comprises a base 1 (FIG. 1) on which is mounted a vertical hollow fixed axis 2, bearings (bearing in this case) 3 and 4, a drum 5 mounted on a hub 6, a casing 7 and tubes 8 and 9 serving to bring the liquid to be purified to the axis 2 of the centrifuge and to leave the purified liquid of the axis 2. In the axis 2 is performed a channel 10 by which the liquid to be purified arrives at the slots 11 (FIGS. 1, 2) arranged tangentially, the walls of which

  are made in a logarithmic spiral, and

  12 for the evacuation of the liquid from the cavity of the drum 5, there are also provided in the hub 6 orifices 13 (FIG. 1, 3) arranged tangentially and in the form of a converge, while in axis 2 are practiced

orifices 14 (FIGS. 1, 3).

  Between the rotating hub 6 and the fixed axis 2, there are provided open or non-contact seals 15, 16, 17 for limiting drainage leakage, as well as passages for the passage of liquid from channel 10 into the

  tube 18 communicating with the tubing 9.

  The drum 5 encloses a perforated cylinder 21 with thin walls mounted in the grooves 19 and 20 and pierced with a

  large number of holes 22 whose diameter is much greater than

  the size of the impurity particles is

  in the centrifuge. The portion 23 of the cylinder 21 arranged opposite the openings 12 of the hub 6 is

solid wall.

  The operation of the centrifuge is as follows.

  The liquid to be purified under a pressure of up to 0.5 MPa is brought inside the drum by the tangential slots 11 made in the axis 2 and through the openings 12. After having passed through the internal cavity of the drum 5, the liquid is directed towards the return circuit through the orifices 13, 14 and the outlet tube 18 communicating with the tubing 9. The drum of the centrifuge is rotated by the liquid to be purified itself, when its passage through said slot 11, openings 12 and orifices 13. Under the effect of centrifugal forces acting inside the drum 5, the liquid gets rid of impurities whose weight

  specific is greater than that of the liquid to be purified.

  In the embodiment envisaged, an insert made in the form of a perforated cylinder 21 (FIG. 1) mounted inside the drum 5 concentrically with respect thereto and presenting a

  part with a solid wall 23 disposed in its lower part

  facing the slots 11 of the axis 2 and the openings 12 of the hub 6, protects the dirt deposits on the inner surface of the drum 5 against the action

  dynamics of the jets of liquid to be purified leading to

  12, both during the start-up of the cen-

  trifuge only in the case of non-stable flow rates of the liquid to be purified. During startup of the centrifuge, the rotational speed of the drum 5 is less than the predicted speed for a period of time. Under these conditions, the field of centrifugal forces is still weak and the relative velocities of the liquid to be purified by

  drum walls can reach an important value

  aunt, so that the liquid may cause impurities deposited at said walls, if there is not a device that protects the depots. The perforated cylinder 21 reduces the relative velocities of the liquid in the space between the cylinder and the inner wall of the drum 5.

  unstable operating regimes of the centrifuge.

  The velocities of the liquid inside the drum 5 are the highest in the zone where the liquid jets open out of the openings 12 of the hub 6. To protect the walls of the drum 5 against the dynamic action of these jets, the part 23 of the perforated cylinder 21 arranged in

  face of the openings 12 is made to solid wall.

  The influence of the perforated cylinder in the mode of

  The invention, according to the invention, is most pronounced in cases where the centrifuge is used in the return circuits of the hydraulic systems of the mobile machines, characterized by suddenly variable flow rates of the engine liquid which the speeds of the engine liquid jets entering the drum 5 exceed the expected values, as well as in cases where the centrifuge is used in hydraulic systems using

  motor fluids of high viscosity, for example when

  that hydraulically driven mobile machines are

exploited in winter.

  To reduce the speeds of the jets of liquid to be purified opening openings 12 of the hub 6 in the inner cavity of the drum 5, the side walls of the slots 11 arranged tangentially in the axis 2 are

  made in a logarithmic spiral. This makes it possible

  determining the radial velocity of the liquid jets arriving at the openings 12 and then in the cavity of the drum 5, without reducing the tangential component of the velocity of these jets, which ensures the expected speed of rotation of the drum 5. In this way, it decreases the speed of the liquid jets acting on the solid wall portion 23 of the cylinder 21 and thus avoids the removal of impurities deposited at the inner wall of the drum 5. In the end, all these measures to prevent the removal of the impurities contribute to the improvement of the quality of

the cleaning of the engine liquid.

  In addition, the improvements according to the invention improve the energy balance of the centrifuge. Unlike known centrifuges o, to avoid

  removal of impurities, nozzles are used.

  placed in the inlet area of the liquid in the drum

  and increasing the hydraulic resistance of the centrifuge

  the intermediate part made in the form of a perforated cylinder 21 disposed at a relatively large distance

  openings 12 does not cause any sen-

  energy losses, since the liquid jets decelerated by the solid-wall portion 23 of the cylinder 21

  have a much lower speed than at the exit of

  12. The fact that the walls of the slits 11 are made in tangential spiral spiral arranged in the tangential direction, ensures favorable conditions of supply of the liquid to the openings 12, decreasing the

  Hydraulic power losses in the centrifuge.

  To reduce the hydraulic power losses at the liquid outlet of the drum of the centrifuge, the orifices 13 of the hub 6 are made in the form of a

  converge, which reduces the water resistance

  when entering the liquid in these orifices and

  improving the orientation of the liquid stream leaving the tangential orifices 13. This last improvement also makes it possible to reduce the hydraulic power losses,

  while ensuring the required speed of rotation of the drum.

he

Claims (2)

R E V E N D I C A T I 0 N S   1.- Centrifuge for the purification of liquid liquids   used in hydraulic systems, of the type in which the hub (6) carrying a drum (5) enclosed in an envelope (7) is mounted by means of bearings (3,4) on a vertical hollow shaft (2) fixed in base (1) of the center   trifuge and provided with slots (11) arranged tangentially   for the forced feeding of the liquid to be purified into the drum (5) through openings (12) made in the hub (6) and disposed opposite these slots (11) and orifices (13) made tangentially in the   hub (6) for the evacuation of the purified liquid, characterized   in that it comprises a perforated cylinder (21) to   thin wall housed inside the drum (5) concentric   only thereto, the portion (23) of the cylinder (21) located in the lower part of said drum opposite the slots (11) of the shaft (2) being solid wall or devoid of perforations.   2. Centrifuge according to claim 1, characterized   in that the tangential slots (11) of the axis (2) arranged in front of said solid-walled portion (23)   perforated cylinder (21) have side walls   logarithmic spirals and that the tangential orifices   Tiels (13) of the hub (6) are in the form of convergent.