GB1585998A

GB1585998A - Bearings for carrying high loads

Info

Publication number: GB1585998A
Application number: GB16443/78A
Authority: GB
Original assignee: Gutehoffnungshutte Sterkrade AG
Current assignee: Gutehoffnungshutte Sterkrade AG
Priority date: 1977-04-27
Filing date: 1978-04-26
Publication date: 1981-03-11
Also published as: IT1094730B; CH624740A5; FR2396204A1; IT7822727A0; YU92178A; FR2396204B3

Abstract

The device comprises a thin high-pressure tube (1) made of metal or plastic and is recessed into a groove (15), open towards the lower sliding surface, in an elastomer plate (4). One end of the lubricant feed device (1) opens into a lubricant distributor (2) which is arranged approximately in the centre of the elastomer plate. It comprises a short piece of tube, open at both ends, through which the lubricant reaches the level of the two sliding surfaces and with a sufficiently high pressure, spreads out from there across the two sliding surfaces as a thin film (10). The other end of the tube (1) passes through the pot wall (6) in a corresponding bore or in the outwardly continuous groove (15) and, at the outer side of the pot wall or of the bottom, is firmly connected to the latter and to the connection piece (3) for a lubricant injector or screw plug. <IMAGE>

Description

(54) IMPROVEMENTS IN OR RELATING TO BEARINGS FOR CARRYING HIGH LOADS (71) We, GUTEHOFFNUNGSHUT TE STERKRADE AKTIENGESELL SCHAFT, a German Body Corporate, of Bahnhofstr. 66, 42 Oberhausen 11, Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to bearings for carrying high loads, for example for use in bridge construction.

More particularly the invention relates to the lubrication of high load bearings, such as, for example rubber barrel rocking type bearings and plastics bearings, wherein one bearing member consists of plastics material, preferably of PTFE, and the other of metal.

Rubber barrel rocking bearings using a pasty lubricant to reduce the friction between the bearing surfaces have proved to be reasonably satisfactory. After a protracted period of operation however, it has been observed that the lunbricating action of the paste diminishes as the fluid component of the pasty lubricant penetrates over a period into the elastomer under the high prevailing pressure and is thus, effectively, lost. Moreover, leakage of the lubricant at a seal between the barrel wall and cover cannot be entirely prevented over a long period.

For plastics bearings, it has been proposed to impress depressions into the surface of the plastics plate for storing the lubricant.

However, a progressive loss of lubricant occurs during prolonged periods of operation, with resulting deterioration in the lubricating action.

According to the present invention, there is provided a bearing for high loads, comprising a bearing base, a plastics plate supported on the base and a system for feeding lubricant to a surface of the bearing, said system comprising at least one groove extending inwardly from the outside of the bearing, said groove receiving a feed pipe for feeding lubricant to the bearing surface, and said groove being formed in the surface of the bearing base facing towards the inside of the bearing and/or in the plastics plate.

Further according to the present invention, there is provided a bearing for high loads, said bearing comprising a barrel wall, surrounding a barrel base, an elastomeric plate supported by the base and confined by the wall, and a system for feeding lubricant to the surfaces of the bearing, said system comprising at least one groove extending from the barrel wall to the central area of the elastomeric plate and open towards the bearing surface between the elastomeric plate and the barrel base, said groove being formed in the elastomeric plate or in the barrel base, or partially in the elastomeric plate and partially in the barrel base, and feed pipe of metal or plastics material incorporated in the groove and connected to the barrel wall said pipe leading into a pressure-tight pipe section of metal or plastics material acting as a lubricant distributor and which is situated within the elastomeric plate, said pipe section being open towards both surfaces of the bearing, and being displaceable in a plane parallel to the planes of the bearing surfaces.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a vertical cross-section through the centre of a rubber barrel rocking type bearing having a lubrication system in accordance with the invention, the section being taken on line I-I of Figure 2; Figure 2 is a cross-section taken on line II-II of Figure 1; Figure 3, 5a and 5b are vertical crosssections showing different modes of incor porating a feed pipe in the bearing; Figures 4 and 6 are vertical cross-sections showing different forms of lubricant distributor; Figure 7 is a vertical cross-section through a plastics bearing incorporating a lubrication system in accordance with the present invention, the section being taken on line VII-VII of Figure i826ntal action taken 8;; Figure 8 is a horizontal section taken on line VIII-VIII of Figure 7; and Figures 9 to 11 are cross-sections showing various forms of lubricant feed pipe incorporated in the bearing of Figure 7.

The bearing shown in Figures 1 to 6 is of the type described in detail in German Patent No. 1,160,873. The lubricant is fed intermittently or continuously to the surfaces of the bearing by means of a thin high-pressure pipe 1 of metal or plastics material which is of high compressive strength inset into a groove 15 open towards the lower bearing surface of an elastomeric plate 4 of the bearing. Alternatively, the groove may be situated directly in the lower surface of the plate 4 (Figure 3) or in a base plate 7 of the bearing (Figure 5a) or partially in the elastomeric plate 4 and partially in the base plate 7 (Figure 5b).

Depending on the vertical positioning of the lubricant feed pipe 1, the groove space above and/or below the pipe 1 may be filled according to Figures 3 and 5a with a rubber-like or solid filling composition 14.

The pipe 1 may be encased in a sheathing pipe of metal or plastics material.

The lubricant feed pipe 1 leads to a lubricant distributor 2 which is situated approximately at the centre of the elastomeric plate 4. It comprises a short length of pipe open at each end and through which the lubricant reaches the level of the two bearing surfaces and spreads out from the same under appropriately high pressures to form a thin film 10 on the two bearing surface. The pipe 2 may consist of metal or plastics material and may be equipped at both of its ends with an annular sealing lip 11. The lip prevents the elastomeric plate 4 which is under high pressure from penetrating into the pipe. but allows the egress of the lubricant onto the two bearing surfaces.

In the arrangement according to Figures 3 and Sb, the feed pipe passes through the wall of the lubricant distributor without being physically connected to the same and is preferablv installed at right angles to the principal rocking axis of the bearing. the direction of rocking indicated by arrow 12.

During sliding displacement of the central area of the elastomeric plate 4 with respect to the cover and base of the bearing as a consequence of a rocking displacement. the lubricant distributor 2 is correspondingly displaced only in the axial direction of the lubricant feed. The projection of the lubricant feed 1 through the inner wall of the lubricant distributor 2 is selected in accordance with the magnitude of this displacement.

In the arrangement according to Figure Sa, the pipe 1 passes through a groove 15 in the base plate 7 with the inner end of the pipe 1 lying below the lubricant distributor 2.

Different forms of lubricant distributor are illustrated in Figures 4 and 6. In Figure 4 the lubricant distributor 2 may also comprise two components which are pushed one into another telescopically at the centre, and in Figure 6 the distributor has separate annular sealing lips 11.

The pipe 1 passes to the outside through a bore in the lateral wall or rim 6 of the bearing or through the groove 15 in the base, and is firmly connected at the outer side of the wall or of the base, to the same and to a connector element 3 for a lubricant press or a screwed union.

In the case of rubber barrel bearings for very high vertical loads, the bearing will have a large diameter and several lubricant distributors arranged at different positions within the plate 4. The distributors are supplied with lubricant via separate or interconnected lubricant feed pipes 1.

In the arrangement according to Figure 3 the diameter of the pipe 1 is small as compared to the thickness of the elastomeric plate 4, so that its elastic properties are substantially unimpaired in the proximity of the pipe 1. The groove 15 in the elastomeric plate 4 for receiving the pipe 1 may thereby also be small, and the rubber-like filling composition 14 may be omitted in many cases. If an annular gap exists at the point where the pipe 1 passes through the lateral wall 6 the gap may be closed by a sealing ring 13 located at the side of the wall 6 adjacent the elastomeric plate 4.

In the arrangement of Figure 5a, it is merely necessary to cut a groove 15 into the plate 7, into which the pipe 1 is inset and tightly welded to the wall 6. prior to assembly of the bearing. The need for a movable connection between the lubricant distributor 2 and the pipe 1 is thereby avoided. These advantages are somewhat offset by the reduction in the cross-sectional area of the base plate 1 which is stressed under tension in the plane of the plate.

Depending on the stress conditions, the size of the rocking angle. and the deformation of the elastomeric plate 4. the most favourable arrangement according to Figures 3. 5a and 5b will be chosen.

In the embodiment of Figures 7 to 11 a groove extending generally radially from the rim of the bearing base plate. and having an arcuate cross-section is milled into the sur face of the base plate. A thin feed pipe is inset into this groove. The depth of the groove may be equal to or less than the external diameter of the feed pipe. If the depth is less than the pipe diameter, a corresponding groove is also incorporated in the lower surface of a plastics plate supported on the base plate, so that the combined depth of the two grooves is equal to the external diameter of the feed pipe. At its outer end, the feed pipe is joined by welding to the rim of the bearing base plate, and the inner end portion of the pipe is bent upwardly to terminate at the base of a recess in the plastics plate a short distance beneath a bearing surface of the plastics plate.The lubricant forced into the feed pipe from the plate rim by means of a hydraulic press emerges under pressure at the upwardly bent pipe end portion and is distributed over the bearing surface via shallow depressions radiating from same. The return of the lubricant during the return stroke of the press is prevented by a non-return valve incorporated in the upwardly bent pipe end portion.

More particularly according to Figure 7, a steel bearing plate 106 which is provided at its underside with a non-rusting burnished coating 107, slides in known manner on a plastics plate 104. This plastics plate 104 is mset into the surface of a base plate 109, in such manner that its free rim is encircled by the base plate 109 over approximately half the depth of the plate 104. Lubrication pockets and/or lubrication grooves 105 are incorporated in the plastics plate 104, in known manner. A groove 103 extending approximately radially and, into which a feed pipe 101 is inset, is cut into the surface of the base plate 109. The pipe is bent upwardly at its inner end portion 102 and passes through the plastics plate 104 so as to terminate in a shallow recess a short distance below the surface of the plastics plate 104.In this case, the recess is formed by the overlapping ends of several lubrication grooves. At its outer end portion, the feed pipe 101 is joined to the base plate 109 by a welded or bonded joint 113. A connector 108 is provided to connect the pipe to a lubricant press as the outlet of the pipe 101 from the base plate 109. Any groove space remaining after the insertion and fastening of the pipe 101 into the base plate 109, in particular at the outer portion thereof - is filled with a fast-setting plastics filler or the like.

Depending on the size and position of the areas of the bearing surface which are to be supplied primarily with lubricant, several lubricant feeds formed by pipes of high compressive strength inset into grooves may be provided. A feed supplying only an edge portion of the bearing plate with lubricant is illustrated at the right, in Figures 7 and 8.

Figure 9 shows a cross-section through the groove 103 with an inset feed pipe 101. The groove space 111 above the pipe is filled with a hard setting filler composition.

Figure 10 shows a cross-section through the pipe 101 with the groove 103 being formed partially in the base plate 109, and in the plastics plate 104. In this case, the groove depth in the base plate 109 is no more than approximately half the pipe diameter, a corresponding groove being cut into the plastics plate 104.

When the thickness of the plastics plate 104 is greater than the diameter of the pipe 101, the groove may be formed wholly in this plate which leads to reduced production costs.

The upwardly bent end portion of the pipe 101 may be widened to form a funnel shape 102a as shown in Figure 11. The funnel is continued in an upwards direction by a recess in the plastics plate 104 and from which the lubrication grooves start to extend. A check valve 114 incorporated in the widened end portion 102a permits flow of lubricant in an upwards direction only.

In both the embodiments described, the lubrication system can be incorporated relatively easily into the bearing, without causing difficulties in production. The system can be used to feed lubricant continuously or intermittently.

WHAT WE CLAIM IS: 1. A bearing for high loads, comprising a bearing base, a plastics plate supported on the base and a system for feeding lubricant to a surface of the bearing, said system comprising at least one groove extending inwardly from the outside of the bearing, said groove receiving a feed pipe for feeding lubricant to the bearing surface, and said groove being formed in the surface of the bearing base facing towards the inside of the bearing and/or in the plastics plate.

2. A bearing for high loads, said bearing comprising a barrel wall, surrounding a barrel base, an elastomeric plate supported by the base and confined by the wall, and a system for feeding lubricant to the surfaces of the bearing, said system comprising at least one groove extending from the barrel wall to the central area of the elastomeric plate and open towards the bearing surface between the elastomeric plate or in the barrel base, or partially in the elastomeric plate and partially in the barrel base, and a feed pipe of metal or plastics material incorporated in the groove and connected to the barrel wall, said pipe leading into a pressure-tight pipe section of metal or plastics material acting as a lubricant distributor and which is situated within the elastomeric plate, said pipe section being open towards both surfaces of the bearing and being

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. face of the base plate. A thin feed pipe is inset into this groove. The depth of the groove may be equal to or less than the external diameter of the feed pipe. If the depth is less than the pipe diameter, a corresponding groove is also incorporated in the lower surface of a plastics plate supported on the base plate, so that the combined depth of the two grooves is equal to the external diameter of the feed pipe. At its outer end, the feed pipe is joined by welding to the rim of the bearing base plate, and the inner end portion of the pipe is bent upwardly to terminate at the base of a recess in the plastics plate a short distance beneath a bearing surface of the plastics plate.The lubricant forced into the feed pipe from the plate rim by means of a hydraulic press emerges under pressure at the upwardly bent pipe end portion and is distributed over the bearing surface via shallow depressions radiating from same. The return of the lubricant during the return stroke of the press is prevented by a non-return valve incorporated in the upwardly bent pipe end portion. More particularly according to Figure 7, a steel bearing plate 106 which is provided at its underside with a non-rusting burnished coating 107, slides in known manner on a plastics plate 104. This plastics plate 104 is mset into the surface of a base plate 109, in such manner that its free rim is encircled by the base plate 109 over approximately half the depth of the plate 104. Lubrication pockets and/or lubrication grooves 105 are incorporated in the plastics plate 104, in known manner. A groove 103 extending approximately radially and, into which a feed pipe 101 is inset, is cut into the surface of the base plate 109. The pipe is bent upwardly at its inner end portion 102 and passes through the plastics plate 104 so as to terminate in a shallow recess a short distance below the surface of the plastics plate 104.In this case, the recess is formed by the overlapping ends of several lubrication grooves. At its outer end portion, the feed pipe 101 is joined to the base plate 109 by a welded or bonded joint 113. A connector 108 is provided to connect the pipe to a lubricant press as the outlet of the pipe 101 from the base plate 109. Any groove space remaining after the insertion and fastening of the pipe 101 into the base plate 109, in particular at the outer portion thereof - is filled with a fast-setting plastics filler or the like. Depending on the size and position of the areas of the bearing surface which are to be supplied primarily with lubricant, several lubricant feeds formed by pipes of high compressive strength inset into grooves may be provided. A feed supplying only an edge portion of the bearing plate with lubricant is illustrated at the right, in Figures 7 and 8. Figure 9 shows a cross-section through the groove 103 with an inset feed pipe 101. The groove space 111 above the pipe is filled with a hard setting filler composition. Figure 10 shows a cross-section through the pipe 101 with the groove 103 being formed partially in the base plate 109, and in the plastics plate 104. In this case, the groove depth in the base plate 109 is no more than approximately half the pipe diameter, a corresponding groove being cut into the plastics plate 104. When the thickness of the plastics plate 104 is greater than the diameter of the pipe 101, the groove may be formed wholly in this plate which leads to reduced production costs. The upwardly bent end portion of the pipe 101 may be widened to form a funnel shape 102a as shown in Figure 11. The funnel is continued in an upwards direction by a recess in the plastics plate 104 and from which the lubrication grooves start to extend. A check valve 114 incorporated in the widened end portion 102a permits flow of lubricant in an upwards direction only. In both the embodiments described, the lubrication system can be incorporated relatively easily into the bearing, without causing difficulties in production. The system can be used to feed lubricant continuously or intermittently. WHAT WE CLAIM IS:

1. A bearing for high loads, comprising a bearing base, a plastics plate supported on the base and a system for feeding lubricant to a surface of the bearing, said system comprising at least one groove extending inwardly from the outside of the bearing, said groove receiving a feed pipe for feeding lubricant to the bearing surface, and said groove being formed in the surface of the bearing base facing towards the inside of the bearing and/or in the plastics plate.

displaceable in a plane parallel to the planes of the bearing surfaces.

3. A bearing according to claim 2, comprising a connector element at the outer side of the barrel wall or the bearing base for connecting the pipe to a lubricant supply.

4. A bearing according to claim 2 or claim 3, wherein the feed pipe is encased in a sheathing pipe within the elastomeric plate.

5. A bearing according to any one of claims 2 to 4, wherein the lubricant distributor consisting of a pressure-tight pipe section comprises two or more parts which are interconnected by butt joints.

6. A bearing according to any one of claims 2 to 5, wherein the pipe section has annular sealing lips in the area of contact with the two bearing surfaces.

7. A bearing according to any one of claims 2 to 6, wherein a gap between the pipe and barrel wall is internally bridged by a sealing ring.

8. A bearing according to claim 1, wherein the groove in the surface of the bearing base and/or the plastics plate is of circular cross-section, and the feed pipe is of metal or plastics material of corresponding diameter, the pipe being upwardly bent at its inner end portion to extend towards and to communicate with the upper surface of the plastics plate, the outer end portion of the pipe being connected to the rim of the bearing base by welding or bonding.

9. A bearing according to claim 8, wherein the upwardly bent end portion of the feed pipe is enlarged to form a funnel shape.

10. A bearing according to claim 8 or claim 9, wherein the upwardly bent end portion of the feed pipe terminates in a recess in the surface of the plastics plate.

11. A bearing according to any one of claims 8 to 10, wherein lubrication pockets or lubricating grooves in the plastics plate extend radially from the upwardly bent end portion of the feed pipe in the plastics plate.

12. A bearing according to any one of claims 8 to 11, wherein there are a plurality of said feed pipes each located in a respective said groove in the bearing base and/or in the plastics plate.

13. A bearing according to any one of claims 8 to 12, wherein a check valve is installed in the upwardly bent end portion of the or each feed pipe.

14. A bearing according to any one of claims 8 to 13, wherein the groove space not filled by the feed pipe is filled with a hardenable filler.

15. A bearing substantially as hereinbefore described with reference to Figures 1 to 6, or 7 to 11 of the accompanying drawings.

MATHISEN, MACARA & CO.,