GB2051971A - Lubricating Bearings - Google Patents

Abstract

The invention provides apparatus having a rolling bearing and means for lubricating the bearing. A first flinger (35) picks up oil from a reservoir (33) and throws it through a first aperture (36) into a first chamber (29). Oil falls by gravity down the chamber to a second aperture (37) and through the aperture to bearings (13 and 14). Oil passes through the bearings to second and third fingers (38 and 39) which throw the oil through third and fifth apertures (40 and 42) and into a second chamber (30). Oil falls by gravity down second chamber (30) to a fourth aperture (41) and passes through the fourth aperture back to the reservoir. The invention has particular application to mounting industrial fans. <IMAGE>

Description

SPECIFICATION Apparatus Having a Rolling Bearing and Means br Lubricating the Bearing This invention concerns apparatus having a rolling bearing and means for lubricating the bearing.

In one aspect the invention provides apparatus having a rolling bearing and means for lubricating the bearing, the apparatus comprising a housing, a shaft extending substantially horizontally within the housing and through opposite axial end walls of the housing, a rolling bearing fixed to and within the housing and supporting the shaft for rotation about its longitudinally extending axis, a casing located outside of the housing and forming with the housing two chambers sealed from the atmosphere and separated from each other at the top of the housing, the chambers extending from the top of the housing one down each side of the housing, a barrier fixed to the housing and extending radially inwardly towards the shaft, an oil reservoir formed in the housing below the shaft and on the opposite axial end of the barrier to the bearing, the barrier providing a wall of the reservoir, the oil reservoir and the bearing being located between seals which seal between the shaft and the housing, a first flinger mounted on the shaft and extending into the oil reservoir, a first aperture in the housing above the oil reservoir, which first aperture lies on a radius from the first flinger and opens into a first one of the chambers, a second aperture in the housing below the first aperture which second aperture opens into the first chamber and is located at one axial end of the bearing, a second flinger mounted on the shaft and at the other axial end of the bearing to the second aperture, the second aperture and second flinger being located on the bearing axial end of the barrier, a third aperture in the housing above the oil reservoir, which third aperture lies on a radius from the second flinger and opens into the second one of the chambers, and a fourth aperture in the housing below the third aperture which fourth aperture opens into the second chamber and is located on the oil reservoir axial end of the barrier, all such that with oil in the reservoir, the first flinger extending into the oil and the shaft rotating about its longitudinal axis, oil is thrown radially outwardly by the first linger and through the first aperture into the first chamber, the oil then falls down in the first chamber to the second aperture and then passes through the second aperture to the bearing, the oil then passes through the bearing to the second flinger and is thrown radially outwardly by the second flinger through the third aperture and into the second chamber, the oil then falls down in the second chamber to the fourth aperture and then passes through the fourth aperture and into the oil reservoir.

The bearing may be such that when the shaft is rotating and oil is circulating, the bearing has a pumping action and pumps oil towards the second flinger.

The housing may have a circular internal section perpendicular to the shaft axis, and each aperture lying as a radius from a flinger may be a circumferentially extending slot.

A valve may be provided at the second aperture to enable the flow rate of oil to the bearing to be controlled.

The bearing may be an angular contact ball bearing arranged adjacent to and back-to-back with a second angular contact ball bearing, the second aperture may be located axially between the two bearings, the second fiinger may be mounted axially between the barrier and the first bearing, a third flinger may be mounted on the shaft on the axial end of the second bearing facing away from the first bearing, and a fifth aperture may be provided in the housing above the fourth aperture, which fifth aperture may lie as a radius from the third flinger and open into the second chamber.

A sixth aperture may be provided in the housing above the first aperture, which sixth aperture may open into the first chamber and lie at the said one axial end of the first bearing to allow oil mist to pass from the first chamber to the first bearing, and a seventh aperture may be provided in the housing above the third aperture, which seventh aperture may open into the second chamber and lie on the oil reservoir end of the barrier to allow oil mist to pass from the second chamber to the oil reservoir.

In another aspect the invention provides in combination, a shaft rotationally mounted in a housing by a rolling bearing and extending through the housing walls with seals at each end between the housing and the shaft, a first flinger on the shaft to rotate therewith, a barrier extending from the housing wall to between a portion of the periphery of the first flinger and the bearding, E first duct which extends from an inlet opening radially aligned with the first flinger out through the wall of the housing and then back through the wall of the housing to an outlet opening adjacent to and to one axial side of the bearing and on the bearing axial side of the barrier, a second Fiinger on the shaft to rotate therewith and located on the same axial side of the barrier as the bearing and on the opposite axial side of the bearing to the outlet opening ai the first duct, and a second duct which extends from en inlet opening radially aligned with the second flinger out through the wall of the housing and then back through the wall oi the housing to an outlet opening on the axial side of the barrier remote from the bearing, such that in normal use, the shaft extends substantially horizontally, the in let openings and the outlet openings of the ducts are so located relative to one another that the inlet opening of one duct is above the outlet opening of the same duct, the barrier is at the bottom of the housing and provides one wall of an oil reservoir into which the first flings dips and picks up oil which it then flings off, some of the oil flung off by the first flinger enters the inlet opening of the first duct whence it flows by gravity in the first duct until oil passes out of the outlet opening of the first duct and through the bearing, oil which has passed through the bearing is flung by the second flinger into the inlet opening of the second duct whence it flows by gravity in the second duct until oil passes out of the outlet opening of the second duct to replenish the oil in the reservoir.

An embodiment of the invention will now be described by way of example, reference being made to the accompanying drawings, of which: Figure 1 is an axial section through apparatus according to the invention; Figure 2A is half of a section on A-A of the apparatus shown in Figure 1; Figure 2B is half of a section on B-B of the apparatus shown in Figure 1; and Figure 3 is a plan of the apparatus shown in Figure 1 and Figures 2A and 2B with the top removed.

The apparatus shown comprises a housing 10, a shaft 11 extending substantially horizontally within the housing and through opposite end walls of the housing, of which only one, 12, is shown, and two single row angular contact ball bearings 13 and 14 fixed to and within the housing and supporting the shaft for rotation about its longitudinally extending axis.

Each bearing 13, 14 comprises an inner race ring 1 5, 16 secured to the shaft 11, an outer race ring 1 7, 18 secured in the housing 10, a row of balls 19, 20 and a cage 21,22 locating the balls.

The bearings 13 and 14 are arranged adjacent to each other and back-to-back, a ring 23 mounted on the shaft 11 spaces the inner race rings 15 and 16 apart and a ring 24 secured in the housing 10 spaces the outer race rings 1 7 and 18 apart.

The housing 10 has a circular internal section perpendicular to the axis of the shaft 11. A casing 25 is located outside of the housing 10 and has longitudinally extending upstanding walls 26 and 27 formed integrally with the housing and one on each side of the housing and integrally formed end walls. A separately formed plate 28 is fixed to form the top of the casing 25. The casing 25 forms with the housing 10 a first chamber 29 and a second chamber 30 sealed from the atmosphere and separated from each other at the top of the housing by a radially and longitudinally extending projection 31 integral with the housing.

The chambers 29 and 30 extend from the top of the housing 10 one down each side of the housing.

An annular barrier 32 is fixed to the housing 10 and extends radially inwardly towards the shaft 11.

An oil reservoir 33 is formed in the housing 10 below the shaft 11 and on the opposite axial end of the barrier 32 to the bearings 13 and 14, the barrier forming a wall of the reservoir.

The oil reservoir 33 and bearings 13 and 14 are located between seals which seal between the shaft 11 and the housing 10. Referring to Figure 1 , the end wall 12 extends radially inwardly to shaft 11 to form a sealing gap therewith. Also inwardly of the housing 10 are two lock nuts 34 screwed onto the shaft 11 the outer of which forms with the end wall 12 a further seal. Additional seals may be provided externally of the housing 10.

A first flinger 35 is mounted on the shaft 11 on the axial end of the barrier 32 opposite to the bearings 13 and 14 so that the flinger extends into the oil reservoir 33. A first aperture 36 is provided in the housing 10 above the oil reservoir 33, lies on a radius from (i.e. is radially aligned with) the first flinger 35 and opens into the first chamber 29. The first aperture 36 is formed as a circumferentially extending slot. A second aperture 37 is provided in the housing 10 below the first aperture 36, opens into the first chamber 29 and is located axially between the two bearings 1 3 and 14, that is, located at one end of each bearing 1 3, 14 and on the bearing end of the barrier 32.

A second flinger 38 is mounted on the shaft 11 axially between the bearing 13 and the barrier 32 and a third flinger 39 is mounted on the shaft 11 on the axial end of the bearing 14 facing away from the bearing 13, the two flingers 38 and 39 thus being located on the bearing axial end of the barrier 32.

A third aperture 40 is provided in the housing 10 above the oil reservoir 33 which aperture is radially aligned with the second flinger 38 and opens into second chamber 30. A fourth aperture 41 is provided in the housing 10 below the third aperture 40, which fourth aperture 41 opens into the second chamber 30 and is located on the oil reservoir axial end of the barrier 32. A fifth aperture 42 is provided in the housing 10 above the oil reservoir 33 and above fourth aperture 41, which fifth aperture is radially aligned with the third flinger 39 and opens into the second chamber 30. Both third and fifth apertures 40 and 42 are formed as circumferentially extending slots.

Apertures 40, 41 and 42 are shown in Figure 1 to give their relative position. They are however formed in that part of the housing 10 removed to give the section.

In use of the apparatus there is oil in the reservoir 33 into which oil the first flinger 35 extends or dips and the shaft 11 rotates about its longitudinal axis carrying the flingers 35, 38 and 39 with it. Oil picked up by the first flinger 35 is thrown or flung radially outwardly. Some of this oil passes through first aperture 36 and into first chamber 29. Oil in first chamber 29 falls down under gravity to second aperture 37. Oil then flows through second aperture 37 to the bearings 13 and 14. To enable the flow of oil to the bearings to be controlled a valve 43, for example a needle valve, is provided at the second aperture 37.

Angular contact ball bearings in common with other bearings such as taper roller bearings have a pumping action in use. The two bearings 13 and 14 have a pumping action which pumps oil from between the two bearings out towards flingers 38 and 39 respectively. Flingers 38 and 39 throw a fling oil which has passed through bearings 13 and 14 radially outwardly through third and fifth apertures 40 and 42 respectively and into second chamber 30. Oil then falls by gravity down in the second chamber 30 and passes out through aperture 41 and into the oil reservoir 33 to replenish the oil.

By continuously circulating oil through the bearings and in the direction of their pumping action, the bearings are efficiently cooled and iubricated and thus the shaft can be run at high speeds. Churning of the oil is prevented because no substantial amounts of oil will collect at the bottom of the bearings. Oil discharged into chambers 29 and 30 is cooled upon contacting the surfaces of the casing walls. Also by returning the oil to the reservoir, the oil has a further chance to cool before reaching the bearings again. By keeping the oil temperature down and by avoiding churning breakdown of the oil is kept to a minimum thus prolonging its life.

In practice, the first flinger 35 will be made overefficient, that is more oil will be thrown through first aperture 36 than is allowed to flow through aperture 37. Thus a constant head of oil is maintained in first chamber 29 with the excess oil falling back through aperture 36 into the reservoir 33. This enables a constant flow of oil to be achieved through the bearings 13 and 14.

Aperture 41 is larger than aperture 37 so that there is no obstruction to the flow of oil from second chamber 30 to the reservoir 33.

The second and third oil flingers 38 and 39 will also be over efficient to evacuate oil outboard of the bearings 13 and 14 to maintain a minimum and constant oil level in the bearings for effective operation, the amount of oil flow being determined completely by metering means, that is, the needle valve 43.

An oil mist may be generated by the action of the flingers 35, 38 and 39 and by the bearings 13 and 14 with a head of oil being maintained in chamber 29 oil mist in the chamber will not be able to reach the bearings 13 and 14. A sixth aperture 44 is thus provided in housing 10 above first aperture 36, which sixth aperture opens into the first chamber 29 and lies between the two bearings 1 3 and 14 to allow oil mist to pass from chamber 29 to the bearings. To allow oil mist in chamber 30 to pass to the reservoir 33, a seventh aperture 45 is provided in the housing 10 above the third and fifth apertures 40 and 42 respectively, which seventh aperture opens into the second chamber 30 and lies on the oil reservoir end of the bearings 13 and 14 to allow oil mist to pass from chamber 30 to the reservoir.

The inlet apertures 36, 40 and 42 to the chambers 29 and 30, the outlet apertures 37 and 41 from the chambers and the chambers themselves can be considered as ducts having inlet and outlet openings and extending out and back through the walls of the housing.

In use of the apparatus according to the invention, the pressure inside the housing 10 may be slightly greater than atmospheric so that there might be a slight leakage of oil out from the housing 10 but no contaminants will enter. Also circulation of any oil mist may be assisted by the pumping action of the bearings.

The casing 25 need not be formed having upstanding walls cast integrally with the housing 10. Instead a sheet metal casing may be prefabricated and bolted or otherwise fixed to the housing 10.

Although the embodiment described and illustrated has two bearings, the invention is equally applicable to more than two bearings.

Also bearings other than angular contact ball bearings can be used, for example taper roller bearings which also have a pumping action, deep groove ball bearings, cylindrical and needle roller bearings and spherical roller bearings.

When for example deep groove ball bearings are used, the second and third flingers will fling oil away from the outboard sides of the bearings. The flow of oil to between the bearings will produce a head and will feed oil through the bearings no pumping action will therefore be required by the bearings to produce a flow of oil.

It is feasible that the invention could be applied to a single bearing. For example, single bearings could be spaced apart one at each end of the tubular housing.

The invention has particular application to industrial fans which are often mounted in places which make servicing difficult. The invention allows a fan to be mounted on the shaft 11, the shaft to be run and valve 43 adjusted for the right oil flow for the bearings running at a particular speed. The fan can then be left, There is no pump required for circulating the oil and which might break down so servicing is at a minimum.

Claims (8)

Claims

1. Apparatus having a rolling bearing and means for lubricating the bearing, the apparatus comprising a housing, a shaft extending substantially horizontally within the housing and through opposite axial end walls of the housing, a rolling bearing fixed to and within the housing and supporting the shaft for rotation about its longitudinally extending axis, a casing located outside of the housing and forming with the housing two chambers sealed from the atmosphere and separated from each other at the top of the housing, the chambers extending from the top of the housing one down each side of the housing, a barrier fixed to the housing and extending radially inwardly towards the shaft, an oil reservoir formed in the housing below the shaft and on the opposite axial end of the barrier to the bearing, the barrier providing a wall of the reservoir, the oil reservoir and the bearing being located between seals which seal between the shaft and the housing a first flinger mounted on the shaft and extending into the oil reservoir, a first aperture in the housing above the oil reservoir, which first aperture lies on a radius from the first flinger and opens into a first one of the chambers, a second aperture in the housing below the first aperture, which second aperture opens into the first chamber and is located at one axial end of the bearing, a second flinger mounted on the shaft and at the other axial end of the bearing, to the second aperture, the second aperture and second flinger being located on the bearing axial end of the barrier, a third aperture in the housing above the oil reservoir, which third aperture lies on a radius from the second flinger and opens into the second one of the chambers, and a fourth aperture in the housing below the third aperture, which fourth aperture opens into the second chamber and is located on the oil reservoir axial end of the barrier, all such that with oil in the reservoir, the first flinger extending into the oil and the shaft rotating about its longitudinal axis, oil is thrown radially outwardly by the first flinger and through the first aperture into the first chamber, the oil then falls down in the first chamber to the second aperture and then passes through the second aperture to the bearing, the oil then passes through the bearing to the second flinger and is thrown radially outwardly by the second flinger through the third aperture and into the second chamber, the oil then falls down in the second chamber to the fourth aperture and then passes through the fourth aperture and into the oil reservoir.

2. Apparatus as claimed in claim 1 , wherein the bearing is such that when the shaft is rotating and oil is circulating, the bearing has a pumping action and pumps oil towards the second flinger.

3. Apparatus as claimed in claim 1 or 2, wherein the housing has a circular internal section perpendicular to the shaft axis, and each aperture lying on a radius frnm a flinger is a circumferentially extending slot.

4. Apparatus as claimed in claim 1, 2 or 3, wherein a valve is provided at the second aperture to enable the flow rate of oil to the bearing to be controlled.

5. Apparatus as claimed in any preceding claim, wherein the bearing is an angular contact ball bearing arranged adjacent to and back-toback with a second angular contact ball bearing, the second aperture is located axially between the two bearings, the second flinger is mounted axially between the barrier and the first bearing, a third flinger is mounted on the shaft on the axial end of the second bearing facing away from the first bearing, and a fifth aperture is provided in the housing above the fourth aperture, which fifth aperture lies on a radius from the third flinger and opens into the second chamber.

6. Apparatus as claimed in any preceding claim, wherein a sixth aperture is provided in the housing above the first aperture, which sixth aperture opens into ihe first chamber and lies at the said one axial end of the first bearing to allow oil mist to pass from the first chamber to the firs: bearing, and a seventh aperture is provided in the housing above the third aperture which seventh aperture opens into the second chamber and lies on the oil reservoir end of the barrier to allow oil mist to pass from the second chamber to the oil reservoir.

7. Apparatus having a rolling bearing and means for lubricating the bearing substantially as herein described with reference to and as shown in the accompanying drawings.

8. In combination, a shaft rotationally mounted in a housing by a rolling bearing and extending through the housing walls with seals at each end between the housing and the shaft, a first flings on the shaft to rotate therewith, a barrier extending from the housing wall to between a portion of the periphenp G, the first flinger and the bearing, a first duct which extends from an inlet opening radially aligned with the first flinger out through the wall of the housing and then back through the wall of the housing to an outlet opening adjacent to and to one axial side of the bearing and on the bearing axial side of the barrier, a second flinger on the shaft to rotate herewith and located on the same axial side of the barrier as the bearing and on the opposite axial side of the bearing to the outlet opening of the first duct, and a second duct which extends from an inlet opening radially aligned with the second flinger out through the wall of the housing and then back through the wall of the housing to an outlet opening on the side of the barrier remote from the bearing, such that in normal use, the shaft extends substantially horizontally, the inlet openings and the outlet openings of the ducts are so located relative to one another that the inlet opening of one duct is above the outlet opening of the same duct, the barrier is at the bottom of the housing and provides one wall of an oil reservoir into which the first flinger dips and picks up oil which it then flings orff, some of the oil flung off by the first flinger enters the inlet opening of the first duct whence it flows by gravity in the first duct until oil passes out of the outlet opening of the first duct and through the bearing, oil which has passed through the bearing is flung by the second flinger into the inlet opening of the second duct whence it flows by gravity in the second duct until oil passes out a the outlet opening of the second duct to replenish the oil in the reservoir.