GB2191824A - A bearing housing assembly - Google Patents

Abstract

A bearing housing assembly comprises a housing having an upstanding wall 11 and a bore 12 opening into the wall. A bearing 13 is supported in the housing. A shaft 14 is supported in rotation by the bearing and extends along the bore. In use of the assembly, lubricant flows down the wall 11 towards the shaft 14. Lubricant is intended to fall onto the shaft 14 before working its way towards the bearing 13. In some circumstances, the lubricant flows round the periphery of the bore 12 and not onto the shaft. The assembly includes means 15 causing, in use of the assembly, some of the lubricant flowing down the wall 11 towards the shaft 14 to fall from the means towards the shaft. The means may include recesses 15 in the bore 12 or a plate fixed to the wall (Fig. 7, not shown). <IMAGE>

Description

SPECIFICATION A bearing housing assembly The invention concerns a bearing housing assembly comprising: a housing which includes an upstanding wall and a bore which opens into the wall; a bearing which is supported in the housing, and a shaft which is supported in rotation by the bearing and extends along the bore; the upstanding wall extending cross-wise of the shaft and the plane of the wall intersecting the shaft, and all such that, in use of the assembly, lubricant flows down the upstanding wall towards the shaft.

In this specification the term "bore" not only includes those with a circular cross-section but also chose with a non-circular cross-section and also includes a recess which is part circular in cross-section.

Such an assembly can be found in a gear box. A splash lubrication system is known which supplies lubricant to the bearing by means of a rotating body, usually a gear. This system works well when the lubricant is supplied directly to the bearing. However, problems arise when the lubricant is splashed onto the wall and the lubricant is allowed to flow down the wall in order for it to fall on to the shaft and find its way to the bearing. When the rate of flow of the lubricant down the wall is substantial then this system is statisfactory given that the lubricant requirement of the bearing is not normally high. However when the flow rate is low, due normally to low speed or adverse geometry, there is a major problem in that the edge of the housing bore forms a path for the lubricant around the bore. To counter this, some assemblies include weir plates or a circulating pump assembly.A weir plate assembly has the disadvantage in that lubricant has little chance of being renewed and in that if forms a trap for dirt. Weir plates are also difficult, if not impossible, to instal in some circumstances. A circulating pump assembly can be costly to provide and instal.

According to the invention, the assembly includes means causing, in use of the assembly, some of the lubricant falling down the upstanding wall towards the shaft to fall from the means towards the shaft.

In one aspect, the means may include one or more longitudinally extending recesses in the bore, the or each recess being positioned above the shaft and opening into the upstanding wall.

Such a recess or recesses may be provided when producing the housing, for example, by being cast in place or may be provided afterwards in a post assembly procedure. The or each recess will break the path of the luricant around the bore and will form, in effect, a drip channel.

Preferably the means includes two recesses which are positioned on opposite sides of a vertical plane in which lies the longitudinal axis of the shaft, each recess having a mouth which opens into the bore and each mouth having lips which extend longitudinally, the distance of the nearer lip of each mouth to the vertical plane being no greater than the radius of the shaft measured at the place where the plane of the wall intersects the shaft.

The width of the path of lubricant flowing down the wall towards the shaft which is caused to fall onto the shaft extends from the uppermost point of one recess cross-wise of the shaft to the uppermost point of the other recess.

Preferably the bore is circular in cross-section, and the or each recess is part circular in crosssection.

In another aspect, the means may include a plate which is fixed to the upstanding wall above the shaft and extends inside the periphery of the bore.

The plate can have a variety of shapes and configurations all intended to break the path of the lubricant around the bore. For example, grooves or channels may be provided on the plate to direct the lubricant.

Preferably, an plate has one or more vertically depending fingers extending inside the periphery of the bore, the or each finger lying directly above the shaft.

Some of the lubricant flowing down the upstanding wall will flow over the plate and down the or each finger to fall onto the shaft.

Preferably, the upper surface of the plate is shaped to gather lubricant and a lower surface of the plate is shaped to direct lubricant to the or each finger.

The shape may be a simple concave depression. The width of the plate is a determining factor in how much lubricant will fall onto the shaft. The plate can be as wide as the diameter of the shaft or may, for example, have cross-wise extending wings wider than the bore.

The invention also provides a method of causing some of the lubricant when flowing down the upstanding wall towards the shaft to fall towards the shaft, the method comprising forming one or more longitudinally extending recesses in the bore, the or each recess being positioned above the shaft and opening into the upstanding wall.

Such a method is applicable to an assembly already installed.

The recesses may be formed by drilling into the upstanding wall and preferably each recess is formed by first drilling a pilot hole at a location on the upstanding wall which is spaced from the periphery of the bore and then drilling a larger diameter hole, the circumference of which intersects the periphery of the bore.

In another aspect, the invention provides a hand-held jig for use in a method in which the or each recess is formed by first drilling a pilot hole at a location on the upstanding wall which is spaced from the periphery of the bore and then drilling a larger diameter hole, the circumference of which intersects the periphery of the bore for locating the centre of the hole to be drilled, the jig comprising a support, an L-shaped plate and a ball and socket joint connected to one limb of the L-shaped plate and the support, the other limb of the L-shaped plate having a bore.

Such a jig provides a simple and easy to use tool for determining the centre of the hole to be drilled. A different position of the bore in the other limb of the L-shaped plate would be used for differing ranges of housing bore size.

Preferably the jig also includes a spirit-level and a second L-shaped plate connected to the support by a second ball and socket joint, the two L-shaped plates being movable towards or away from each other along the support.

With the appropriate markings and position of the bore in the other limb of each of the Lshaped plates, the desired spacing of two holes from each side of a vertical plane in which lies the longitudinal axis of the shaft can be swiftly determined.

Preferably, the L-shaped plates are detachable from the support so that the L-shaped plate having the correct position of the bore in the other limb can be connected to the support for the housing bore size in question.

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, of which: Figure 1 is an end view showing part of an upstanding wall of a housing, a bore and a shaft supported in the bore for rotation by a bearing, with arrows indicating the direction of flow of lubricant; Figure 2 is a partly section side view on ll-ll of Fig. 1; Figure 3 is an end view similar to Fig. 1 but the bore having two longitudinally extending recesses; Figure 4 is a partly sectional side view on IV-IV of Fig. 3; Figure 5 is an enlarged view of part of Fig. 3 including the left hand recess; Figure 6 is a section on VI-VI of Fig. 5; Figure 7 is an end view similar to Fig. 1 but including a plate, which is fixed to the upstanding end wall and above the shaft;; Figure 8 is a view of a hand-held jig for use in locating the centre of a hole to be drilled in the upstanding wall; and Figure 9 shows how the jig would be used.

Figs. 1 and 2 show part of a gear box with a housing 10 having an upstanding wall 11 of the gear box casing and a circular bore 12 which opens into the wall. A spherical roller bearing 13 is supported in the bore 12 and supports in rotation a shaft 14 which extends along the bore 12. The upstanding wall 11 extends cross-wise of the shaft 14 and the plane of the wall intersect the shaft. Lubrication of the bearing 13 is effected by rotating gear splashing lubricant onto the wall 11 so that it flows down the wall towards the shaft 14. With a substantial flow rate, the lubricant will fall onto the shaft 14 and will work its way to the bearing 13. However, with a low flow rate, the lubricant will run around the edge of the bore 12 as shown in Fig. 1 by the arrows and will not fall on the shaft 14.

Referring now to Figs. 3 and 4, one way of overcoming this is to provide two longitudinally extending part-circular recesses 15 in the bore 12, each recess being positioned above the shaft and opening into the wall 11. Each recess 15 is positioned on an opposite side of a vertical plane 16 in which lies the longitudinal axis of the shaft 14. Each recess 15 has a mouth 17 which opens into the bore 12, each mouth 17 having two longitudinally extending lips 18. The distance A of the nearer lip 18 of each mouth 17 to the vertical plane 16 is no greater than the radius of the shaft 14 measured at the place where the plane of the wall 11 intersects the shaft.

Lubricant now flowing down the upstanding wall 10 will be as shown by the arrows with some of it, in a path the width of which extends cross-wise of the bore 12 from the highest parts of the recesses 15, being directed to and falling from the inner lips 18 onto the shaft 14.

The recesses 15 may be formed when casting or machined before final assembly. However, in situations where the gear box is in place and in use, the recesses 15 can be provided by drilling into the upstanding wall 11. In the example shown in Figs. 5 and 6, the housing bore 12 has a diameter of 750 mm and a 3 mm diameter pilot hole 19 is drilled into the upstanding wall 11 on an axis parallel to that of the bore at a distance of approximately 5.3 mm from the periphery of the bore. Then a 12 mm diameter hole 20 is drilled following the pilot hole 19, the larger hole breaking into the periphery of the housing bore 12 to form a gap 21 of approximately 6 mm which extends for about 6 mm into the wall. The centres of the holes 19 and 20 are spaced a distance 22 which is 0.3 times the diameter of the shaft 14 from the vertical plane 16 (see Fig. 3).

Referring now to Fig. 7, instead of breaking the path of the lubricant around the periphery of the housing bore 12 with recesses, a plate 23 is fixed by screws to the upstanding wall 10 above the shaft 14. The plate 23 has two vertically depending figures 24 which extend inside the periphery of the housing bore 12 and lie directly above the shaft 14. The plate 23 has an upper surface 25 which is concave or dished so as to gather lubricant and a lower surface 26 which is concave or dished in a reverse manner to the surface 25 so as to direct lubricant to the fingers 24. Some of the lubricant flowing down the upstanding wall 10 will follow the path indicated by the arrows, flowing down to the lowest part of the curved surface 25, then over the edge of the plate, around the curved surface 26 towards the fingers 24 and falling from the tips of the fingers and onto the shaft 14.The distance A of the tips of the fingers 24 to the vertical plane 16 is no greater than the radius of the shaft 14 measured at the place where the plane of the plate 23 intersects the shaft.

Fig. 8 shows a hand-held jig for use in locating the centre of the hole 20 to be drilled in Figs.

5 and 6. The jig comprises a support handle 27, an L-shaped plate 28 having two limbs 29 and 30 and a ball and socket joint 31 connected to one limb 29 of the L-shaped plate. The other limb 30 has a bore 32. The perpendicular distance B of the centre of this bore 32 to the nearest surface of the limb 29 is chosen according to the diameter of the housing bore 12.

Three sizes are used to cover housing bore diameters in the range of from 80 to 1000 mm as shown in the table.

HOUSING BORE PERPENDICULAR DIAMETER mm DISTANCE B mm 80 to 150 5.86 151 to 400 5.45 401 to 1000 5.30 The hand-held jig can be made more complex and sophisticated to enable the optimum spacing of the centres of the holes from the vertical plane 16 to be found easily and swiftly. For example, the jig may include an elongate support in place of the handle 27, a horizontal spirit level and a second L-shaped plate connected to the support by a second ball and socket joint.

The two L-shaped plates and joints would be movable along the support towards or away from each other by, for example, being screw threaded onto an elongate screw threaded rod, the two plates and joints having opposite hand threads. The L-shaped plates are detachable so that the appropriate ones could be chosen for the size of housing bore.

The spirit level would ensure that the holes drilled would be level with each other and on a line perpendicular to the vertical plane. The elongate support enables the two centres to be marked without having to move the jig each time. And, preferably, the elongate support has marks indicating the relative spacing of the plates from each other according to the diameter of the shaft.

Claims (16)

1. A bearing housing assembly comprsing: a housing which includes an upstanding wall and a bore which opens into the wall; a bearing which is supported in the housing, and a shaft which is supported in rotation by the bearing and extends along the bore; the upstanding wall extending cross-wise of the shaft and the plane of the wall intersecting the shaft, and all such that, in use of the assembly, lubricant flows down the upstanding wall towards the shaft, wherein the assembly includes means causing, in use of the assembly, some of the lubricant flowing down the upstanding wall towards the shaft to fall from the means towards the shaft.

2. An assembly as claimed in Claim 1, wherein the means includes one or more longitudinally extending recesses in the bore, the or each recess being positioned above the shaft and opening into the upstanding wall.

3. An assembly as claimed in Claim 2, wherein the means includes two recesses which are positioned an opposite sides of a vertical plane in which lies the longitudinal axis of the shaft, each recess having a mouth which opens into the bore and each mouth having lips which extend longitudinally, the distance of the nearer lip of each mouth to the vertical plane being no greater than the radius of the shaft measured at the place where the plane of the wall intersects the shaft.

4. An assembly as claimed in Claim 2 or 3, wherein the bore is circular in cross-section, and the or each recess is part circular in cross-section.

5. An assembly as claimed in Claim 1, wherein the means includes a plate which is fixed to the upstanding wail above the shaft and extends inside the periphery of the bore.

6. An assembly as claimed in Claim 5, wherein the plate has one or more vertically depend ing fingers extending inside the periphery of the bore, the or each finger lying directly above the shaft.

7. An assembly as claimed in Claim 6, wherein an upper surface of the plate is shaped to gather lubricant and a lower surface of the plate is shaped to direct lubricant to the or each finger.

8. A bearing housing assembly substantially as herein described with reference to and as shown in Figs. 3 to 7 of the accompanying drawings.

9. For a bearing housing assembly comprising: a housing which includes an upstanding wall and a bore which opens into the wall; a bearing which is supported in the housing, and a shaft which is supported in rotation by the bearing and extends along the bore; the upstanding wall extending cross-wise of the shaft and the plane of the wall intersecting the shaft, all such that, in use of the assembly, lubricant flows down the upstanding wall towards the shaft, a method of causing some of the lubricant when flowing down the upstanding wall towards the shaft to towards the shaft, the method comprising forming one or more longitudinally extending recesses in the bore, the or each recess being positioned above the shaft and opening into the upstanding wall.

10. A method as claimed in Claim 9, wherein the or each recess is formed by drillling into the upstanding wall.

11. A method as claimed in Claim 10, wherein the or each recess is formed by first drilling a pilot hole at a location on the upstanding wall which is spaced from the periphery of the bore and then drilling a larger diameter hole, the circumference of which intersects the periphery of the bore.

12. A method substantially as herein described with reference to and as shown in Figs. 3 to 6 of the accompanying drawings.

13. A hand-held jig for use in a method as claimed in Claim 11 for locating the centre of the hole to be drilled, the jig comprising: a support, an L-shaped plate and a ball and socket joint connected to one limb of the L-shaped plate and the support, the other limb of the L-shaped plate having a bore.

14. A hand-held jig as claimed in Claim 13, wherein the jig also includes a spirit-level and a second L-shaped plate connected to the support by a second ball and socket joint, the two Lshaped plates being movable towards or away from each other along the support.

15. A hand-held jig as claimed in Claim 14, wherein the L-shaped plates are detachable from the support.

16. A hand-held jig substantially as herein described with reference to and as shown in Figs.

8 and 9 of the accompanying drawings.