GB2064347A - Vortex-type oil mist generator for generating lubricant particle suspension in a gaseous carrier - Google Patents

Abstract

The generator comprises an oil storage chamber (1), a funnel-shaped chamber (18) defined by two end surfaces (26), (27) and by a side surface (25) of revolution and provided with inlet openings (19) adapted to create a rotating flow of gas passing therethrough under pressure and with an outlet opening (20) made in the lesser end surface (27) of the funnel-shaped chamber (18). The generator is further provided with a duct having its inlet portion (8) in communication with the oil storage chamber (1) and its outlet portion (33) adapted to supply the oil into the rotating flow of gas. The outlet portion (33) is arranged within the funnel- shaped chamber (18) and extends between the inlet openings (19) and the outlet opening (20) of the funnel- shaped chamber (18). <IMAGE>

Description

SPECIFICATION Vortext-type oil mist generator The present invention relates to apparatus for generating a lubricant particle suspension in a gaseous carrier, and more particularly to vortextype oil mist generators.

The invention can most advantageously be used in association with metallurgy and machinery for the purpose of lubricating machinery parts such as bearing units, gear or link transmissions when there is a large distance between the mist generator and the machinery part to be lubricated and when required to aerosolize liquid lubricant into finely divided particles.

The present invention provides a vortex-type oil mist generator comprising an oil storage chamber, a funnel-shaped chamber defined by two end surfaces and a side surface of revolution and provided with inlet openings adapted to create a rotating flow of gas passing therethrough under pressure and with an outlet opening made in the lesser end surface of the funnel-shaped chamber, and a duct having its inlet portion open to the oil storage chamber and its outlet portion adapted to supply the oil into the rotating flow of gas, wherein, according to the invention, the outlet portion of the duct is located within the funnelshaped chamber and extends therein between the inlet openings and the outlet opening.

The advantage of the proposed generator consists in that such an arrangement of the duct outlet enables the latter to be located within the suction~ area, the pressure produced in said suction area being 0.2 to 0.8 kgf/cm2 lower than in the oil storage chamber.

This causes an excessive amount of oil to be aspirated into the rotating flow of gas, permits generating the oil mist from the oil of lower temperature and/or of high degree of viscosity, and provides an efficient particalization of the oil.

A further advantage of the proposed generator is that the surface of contact between the oil and the mass of gas is increased as well as the length of their interaction time. As a result, the proposed oil mist generator, as compared to the prior art mist generators, provides an increase in the degree of particalization of the oil and permits the generated oil mist to be utilized for effecting lubrication of machinery parts far removed from the generator.

Another advantages of the proposed generator are the generation of high density mist and the transportation of the oil mist to the machinery parts to be lubricated with less expenditure of energy and pressurized gas. This is achieved due to an increased suction created in the zone where the oil is aspirated into the rotating flow of gas, as well as due to a more efficient particalization of the oil contained in the flow of gas.

It is advisable that the outlet portion of the duct be arranged within the funnel-shaped chamber and be adjustable toward and away from the outlet opening of said chamber.

Such arrangement of the duct outlet portion permits the suction and the amount of oil while being aerosolized to be controlled without using a valve. member which has a low reliability because of its choking.

It is further advisable that the duct be provided at the outlet portion thereof with a core disposed therein and having passageways made as spiral grooves being in communication with the interior of said duct.

Such structural arrangement makes it possible to supply the oil to be aerosolized directly into the zone where the rotating flow of gas has maximum velocities, thus increasing the degree of oil mist dispersity. Furthermore, owing to the fact that the passageways provided in the core have the form of spiral grooves, the possibility exists of providing the passageways which have a large length and offer a significant resistance to the flow of oil, thus preventing as aspiration of an excessive amount of oil into the rotating flow of gas without a decrease of cross-section of the passageways, which is of prime importance because of the choking of the passageways with solid particles contained in the contaminated oil.

In one embodiment, the spiral grooves of the core are arranged to have the generatrices coinciding with the direction of the gas vortex rotation.

Such an arrangement of the spiral grooves enables the oil to be aspirated into the rotating flow of gas most efficiently, makes possible to decrease the losses in energy required for aspiration of the oil and to increase the degree of oil mist dispersity.

In another embodiment, the core is rotatably mounted with respect to the outlet portion of the oil delivery duct and is fitted with an impeller mounted coaxially with the core and rigidly secured thereto. In this case, it is essential that the generatrices of the spiral grooves be oppositely directed with respect to the direction of the rotating flow of gas. In doing so, the rotating flow of gas acting upon the impeller blades causes the core to rotate in a direction generally coinciding with the direction of the gas vortex rotation.

Since the axial direction of the generatrices of the spiral grooves is opposite to that of the gas vortex flow, an excessive amount of suction is created by the reactive forces, thus increasing the pressure difference which causes the oil to be aspirated from the oil storage chamber into the rotating flow of gas. Moreover, the reactive forces arised therewith permit withdrawing the solid particles from the grooves, thus preventing the groove choking.

Another advantage of the embodiment mentioned hereinabove resides in that the rotating flow of gas causes the impeller to be rotated, which, in turn, gives rise to an extra mechanical action upon the oil and the oil particles are additionally sheared by the impeller blades, resulting in an increased dispersity of the oil mist.

The invention will now be explained in greater detail with reference to specific embodiments thereof, taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a fragmentary sectional view of an oil mist generator embodying the present invention; FIG. 2 is an enlarged cross-sectional view taken along line Il-Il of FIG. 1; FIG. 3 is a cross sectional view of the upper part of the generator, taken along line Ill-Ill of FIG. 2; FIG. 4 is an enlarged cross-sectional view taken along line IV--IV of FIG. 3; FIG. 5 is an enlarged view of a core adapted to deliver the oil into the rotating flow of gas; FIG. 6 is a view of another embodiment of the core; and FIG. 7 is a sectional view taken along line VIl-VIl of FIG. 6.

Referring now to the accompanying drawings, and initially to FIG. 1, the vortex-type oil mist generator embodying the present invention comprises an oil storage chamber 1, a bottom 2 secured to a head member 3 in a sealing relationship by means of sealing members 4 and fasteners 5 arranged therebetween. The head member 3 has a pressurized gas inlet 6 (FIG. 2) adapted to deliver a pressurized air or any other gas used for aerosolizing the oil, and an oil mist outlet 7 discharging the oil mist to points requiring lubrication.

Also shown in FIG. 1 is a tube 8 having its lower end fitted with a filter 9 and introduced into the oil, while the upper end of said tube is secured to the head member 3.

The inlet 6 (FIG. 2) is adapted to be in communication with an annular cavity 10 defined by a cylindrical bore 11 formed in the head member 3 and by an injector 12 (FIG. 3) and a cover 13, both being axially arranged in said bore.

The injector 12 has a thickening portion 14 which rests on a sealing member 1 5 and is pressed against an annular projection 1 6 of the head member 3 by means of a thread plug 17 which brings the cover 13 into contact with the end surface of the injector 12 so that the pressurized gas is delivered from the annular cavity 10 into a funnel-shaped chamber 18 having tangentially arranged inlet opening 1 9 adapted to create a rotating flow of gas passing therethrough under pressure and is discharged therefrom only through an outlet opening 20. The cover 13 and the thread plug 17 are provided with sealing members 21 and 22 used to separate the gas annular cavity 10 from an oil delivery passageway 23 communicating with the tube 8 through a passageway 24.

The funnel-shaped chamber is defined by a side surface 25 of revolution and by end surfaces 26 and 27.

Extending through the axial openings of the thread plug 17 and the cover 13 is a slide bar 28 mounted for movement in an axial direction and provided with sealing members 29 preventing the oil leakage through the mating surfaces. The upper end of the slide bar 28 has a thread portion 30 thread into a corresponding threaded bore formed in the plug 17. A nut 31 is used to adjustably lock the slide bar 28 in a required position with respect to the outlet opening 20 of the chamber 18. The slide bar is grooved to provide a passageway 32 formed therein and communicating with the passageway 23.

The tube 8 taken in combination with the passageways 24,23 and 32 define an oil delivery duct, the inlet portion thereof being the tube 8, while its outlet portion 33 is arranged within the funnel-shaped chamber 18 and extends between the inlet openings 19 and the outlet opening 20.

The openings 19 and the opening 20 are best shown in FIG. 4. To create a rotating flow of gas, the openings 1 9 are tangentially arranged and extend in the same direction with respect to the axis of the chamber 18 (FIGS. 3 and 4).

FIG. 5 shows an enlarged view of the outlet portion 33 of the oil delivery duct, which accommodates a core 34 tightly arranged therein and having passageways shaped like spiral grooves 35. The axial direction of the generatrices of said grooves coincides with the direction of the gas vortex rotation, as defined by the tangentially arranged openings 19 (FIG. 4).

FIG. 6 is another embodiment illustrating an enlarged view of the outlet portion 33 with a core 36 rotatably mounted therein and having its passageways shaped like spiral grooves 37, the axial direction of the generatrices of said grooves being opposite to the direction of the gas vortex rotation. An impeller 38 is rigidly secured to a pin 39 (FIG. 7) of the core 36 (FIG. 6).

The lower end of the slide bar 28 (FIG. 3) is partly beaded, thus forming projections 40 (FIG. 6) used to restrict an axial displacement of the core 36 (FIG. 8) is a downward direction.

In operation, the pressurized gas is forced through the inlet opening 6 into the annular cavity 10 and then is directed into the tangentially arranged inlet openings 1 9 of the chamber 18. As a result, the gas, as it leaves the inlet openings 19, is swirled and moves in a direction generally axially of its direction of rotation towards the outlet opening 20 of the chamber 18, the tangential velocities being in inverse proportion to the radius.

The rotating mass of gas flowing through the funnel-shaped chamber 18 creates a suction area as well as a difference in pressure between the inlet of the tube 8 introduced into the oil and the outlet portion 33 of the oil delivery duct extending into the suction area. The difference in pressure causes the oil to be aspirated from the oil storage chamber 1 into the rotating flow of gas where the oil is particalized, thus generating the oil mist which is then delivered through the opening 7 to points (not shown) requiring lubrication. The oil supplied directly into the funnel-shaped chamber 18 (FIG. 3) provided with the inlet openings 1 9 used to create the rotating flow of gas tends to increase the particalizing effect due to an increase in the surface of contact between the oil and the mass of gas as well as due to an increase in the length of interaction time.

The suction created within the suction area of the chamber 1 8 varies over the axis of said chamber. The change in the distance between the outlet portion 33 of the oil delivery duct and the outlet opening 20 results in the change in the values of the differential in pressure developed between the end of the tube 8 introduced into the oil and the outlet portion 33 of the oil delivery duct. This admits of control of the suction and quantity of oil to be aerosolized.

It is well known that the distribution of tengential velocities of the gas flow over the radius of gas vortex is nonuniform and has a maximum. From the theory of liquid particle aerosolization, the liquid can be aerosolized into finely divided particles provided that the liquid is supplied into the rotating flow of gas having the highest velocities.

It has been experimentally shown that the suction area created within the chamber 1 8 is shaped like a paraboloid of revolution, the rotating flow of gas reaching the maximum tangential velocities on the outer periphery thereof. As a result, the generated oil mist possesses a high degree of dispersity when the oil is caused to be aspirated into the peripheral zone of the suction area through the use of the core 34 tightly mounted within the outlet portion 33 of the oil delivery duct (FIG. 5) and provided with spiral grooves 35. Spirai arrangement of the passageways grooved in the core 34 enables the length of said passageways to be considerably increased over the same length of the core, thus offering a significant resistance to the oil flow and preventing an excessive amount of oil to be supplied into the rotating flow of gas without an unduly decrease in the cross-sectional area of said passageways, which decrease can lead to the passageway choking with solid particles contained in the contaminated oil.

Moreover, the direction of the generatrices of the spiral grooves 35 coincides with that of the rotating flow of gas. This enables the oil to be directed tangentially with respect to the direction in which the rotating flow of gas moves, increases the effect of aspiration of the oil into the rotating flow of gas, and decreases the size of oil particles.

The core 36 (FIG. 6) having spiral groove 37 (FIG. 8) is rotatably mounted within the outlet portion 33 ops the oil delivery duct. When the rotating flow of gas impacts against the blades of an impeller 38 which is rigidly secured to the core 36, the latter is caused to be rotated at a high rate in a direction generally coinciding with the direction of gas revolution.

The axial direction of the generatrices of the spiral grooves 37 of the core 36 being opposite to the axial direction of the gas flow, the reactive forces arising from the core rotating contribute to an excessive amount of suction and to an increased differential in pressure which causes the oil to be aspirated from the oil storage chamber 1 (FIG. 3) into the rotating flow of gas.

Among other things, said reactive forces will aid in drawing off solid particles contained in this contaminated oil from the grooves 37 (FIG. 6), thus preventing the groove choking. Since the impeller 38 is caused to be rotated by the rotating flow of gas, it mechanically acts on the oil particles which are additionally sheared by the impeller blades with the result that the oil mist is further particalized to a higher degree of dispersity.

Although the present invention is herein disclosed with reference to the oil used as a liquid to be aerosolized, it will be apparent to those skilled in the art that any other liquid may be aerosolized without departure from the essence of the invention.

Claims (6)

1. A vortext-type oil mist generator comprising an oil storage chamber, a funnel-shaped chamber defined by two end surfaces and by a side surface of revolution and provided with inlet openings adapted to create flow of gas passing therethrough under pressure and with outlet opening made in the lesser end surface of the chamber, and a duct having its inlet portion' being in communication with the oil storage chamber and its outlet portion adapted to supply the oil into the rotating flow of gas, the duct outlet portion being arranged within the funnel-shaped chamber and extending between the inlet openings for pressurized gas and the outlet opening.

2. A generator according to Claim 1, wherein the duct outlet portion is adjustable toward and away from the outlet opening of the funnelshaped chamber.

3. A generator according to Claims 1 and 2, wherein the outlet portion of the duct is provided with a core mounted therein and having passageways shaped like spiral grooves being in communication with the interior of the duct.

4. A generator according to Claim 3, wherein the direction of the generatrices of the spiral grooves coincides with the direction of the gas vortex rotation.

5. A generator according to Claim 3, wherein the core is rotatably mounted with respect to the outlet portion of the duct and is fitted with an impeller coaxially arranged with the core and rigidly secured thereto, the direction of the generatrices of the spiral grooves being opposite to the direction of the gas vortex rotation.

6. A generator as hereinbefore described with reference to the accompanying drawings.