GB2121118A

GB2121118A - Cooled plain bearing

Info

Publication number: GB2121118A
Application number: GB08306038A
Authority: GB
Inventors: Hans Grosskurth
Original assignee: GLYCO METALL WERKE
Current assignee: GLYCO METALL WERKE
Priority date: 1982-05-12
Filing date: 1983-03-04
Publication date: 1983-12-14
Also published as: DE3217892A1; GB8306038D0

Abstract

A plain bearing with coolant channels (11) provided in the bearing shell (10), positive guidance of the any coolant through the bearing is ensured due to the fact that the coolant channels are combined into at least one self-contained coolant passage which is sealed off within the bearing from a lubrication system of the bearing (lubricant enters via bore (12)), and which leads from a coolant inlet (14) to a coolant outlet (15). <IMAGE>

Description

SPECIFICATION Cooled plain bearing The invention relates to plain bearings with additional channels in the shell, through which liquid or gaseous coolant is guided.

In a plain bearing of this type, known from US Patent Specification 2,576,141, the bush-shaped shell is made with axially extending channels, through which liquid lubricant is guided, in order to make the cooling of the bearing by the lubricant more effective. For this purpose, the liquid lubricant is first supplied to the bearing running surface in a middle region of the axial length of the bearing. The liquid lubricant flowing out from the bearing running surface at the axial ends thereof is then introduced into the axially extending channels in the shell or bush, and is drawn off again from these approximately in the axial centre of the bearing. In this way, only limited additional cooling can be achieved in plain bearings, but this is in no way sufficient for plain bearings which are to be operated at high speed.

In a plain bearing, known from German Offenlegungsschrift 3,023,317 especially made of compression-moulded plastics and intended for the mounting of roller journals, there is in the centre of the pressure zone of the bearing a cooling-water bore which opens into grooves in the running surface of the bearing. Furthermore, for lubrication of the bearing, there are to be, in the lateral pressure zones of the bearing, two lubricating-grease bores which open into lubricating grooves in the bearing running surface.

As a result, the cooling water and the lubricating grease are both introduced into the bearing running surface and mixed with one another. However, such plain bearings are suitable only for special uses, such as the mounting of roller journals in hot-rolling mills, whereas known plain bearings of this type not suitable for the mounting of shafts and journals in high-performance machines or of shafts or journals running at high speed.

Finally, a water-cooled loose-ring bearing is known from Vogelpohl, Betriebssichere Gleitlager (Reliable plain bearings), Springer-Verlag 1967, page 204, and in this cooling water is guided onto the bearing shell in the interior of the bearing housing. However, in this known loose-ring bearing also, there is no complete separation between the cooling-water circuit and the lubricant system. Moreover, such a known loosering bearing can only be used for the mounting of shafts running at a relatively low speed.

By contrast, the aim of the invention is to provide a positively cooled plain bearing for highperformance machines for the mounting of shafts or journals running at very high peripheral speeds.

This object is achieved, according to the invention, as a result of positive guidance of the coolant through at least one coolant passage which is formed by means of additional coolant channels and is self-contained and which is sealed off within the bearing from the lubrication system and leads from a coolant inlet to a coolant outlet.

The invention provides a self-contained coolant passage which is completely separated within the plain bearing from the lubrication system and which leaves free the choice of cooling medium, the flow rate of the cooling medium and the pressure generated in the cooling medium to meet the need for cooling capacity as closely as possible. Liquid and gaseous media, for example water, oil, air or gas, may be used as a cooling medium.

Advantageously, here, the coolant inlet and coolant outlet can likewise be provided, separately from the lubrication system of the bearing, on or in the bearing holder.

If it is desired or if it is possible to carry out the cooling of the plain bearing by means of the liquid lubricant used and the pressure within the lubrication system is sufficiently high, the coolant passage can be connected, for example in the manner of a by-pass, to the lubrication system or can be made selectively connectable (for example, controlled by means of a valve). However, this connection of the coolant passage to the lubrication system then takes place outside the plain bearing and does not impair the selfcontained positive guidance of the coolant through the coolant passage of the plain bearing.

Even then, the cooling of the bearing remains specific and highly effective and, if desired, controllable.

In an embodiment of the invention, the coolant passage formed by the coolant channels has a passage cross-section of substantially the same size over its entire length. In this embodiment, a substantially uniform pressure gradient prevails over the length of the coolant passage, so that substantially uniform conditions become established over the entire length of the coolant passage.

The coolant channels can be made to meet the particular need for cooling capacity as closely as possible, for example by means of a helical tangential, axial and meander-shaped path. The cross-sectional area of the coolant channels can also be selected to meet the particular need for cooling capacity. Trapezoidal, rectangular or semicircular cross-sectional shapes for the coolant channels may be used.

In the case of a split bearing design, the cooling channels of each part-shell will preferably form their own self-contained coolant passage.

In a preferred embodiment of the invention, the coolant channels are cut as grooves into the outer peripheral surface of the bearing shell or part shell.

If the coolant to be used causes no corrosion, these groove-shaped coolant channels can be covered by the inner face of the bearing holder.

However, a shell element which covers sealingly the coolant channels designed as grooves and which has passages for the coolant inlet and the coolant outlet will preferably be provided on the outer side of the bearing shell or part shell. This shell element protects the bearing holder against corrosion and therefore makes it possible also to use those coolants which would cause corrosion on the bearing holder. When the bearing shell is designed in the form of a bush, the shell element covering the coolant channels sealingly can be a thin-walled corrosionprotection tube shrunk onto the outer side of the bearing bush. In the case of a split design of the bearing shell, the shell element covering the coolant channels sealingly can be a relatively thin corrosion-protection plate attached to the outer surface of the part shell and curved according to the outer surface of the part shell.When the bearing is installed in the bearing holder, this corrosion-protection plate is then pressed firmly and sealingly against the outer surface of the bearing shell. It is therefore often sufficient to attach the corrosion-protection plate to the part shell by riveting or spot-welding.

Embodiments of the invention will now be explained, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 shows diagrammatically, in a radial section along line I-I in Figure 2, a cooled plain bearing with a bush-shaped shell; Figure 2 shows the bearing bush of a plain bearing according to Figure 1 in a side view indicated by the arrow II in Figure 1; Figure 3 shows the corrosion-protection bush of a plain bearing according to Figure 1 in side view indicated by the arrow II in Figure 1; Figure 4 shows diagrammatically, in a radial section along line IV--IV in Figure 5, a cooled plain bearing composed of half-shells; Figure 5 shows a developed view of the outer surface of the half-shell designed with an oil admission bore; and Figure 6 shows an outer developed view of the outer surface of the half-shell without an oil admission bore, in a somewhat modified design.

In the example shown in Figures 1 to 3, there is a bearing bush 10 which has on its outer surface, according to the load on the bearing running surface and the requisite elimination of heat from the bearing, helically arranged coolant channels or grooves 11 which have an approximately rectangular cross-section in the example illustrated. These coolant grooves 11 are deflected at 13, in the region of the lubricating-oil inlet bore 12, in the way shown in Figure 2. There is nevertheless an uninterrupted passage from the coolant inlet 14, indicated by an arrow, to the coolant inlet 1 5.

A thin-walled corrosion-protection tube 1 6 is shrunk over the bearing bush 10, in order to protect the valuable receiving bore of the bearing holder 17, for example the bearing block illustrated by the parts 18 and 19 in Figure 1, against corrosive attack. As shown in Figure 3, the corrosion-protection tube 1 6 has a coolant inflow bore 14' and a collant outflow bore 15' as well as a lubricating-oil inlet bore 12'. Provided correspondingly in one part 1 8 of the bearing block are a feed channel 12" for the lubricating oil, a feed channel 14" for the coolant and a discharge channel 1 5" for the coolant.

The cooled plain bearing shown in Figures 1 to 3 is suitable, for example in a heavy-duty gear, for the mounting of a shaft with a diameter of 80 mm, which runs at a rotational frequency of up to 1 3000 rev/min. This corresponds to a peripheral speed of nearly 55 m/s, while the water cooling of a loose-ring bearing known from Vogelpohl permits a peripheral speed of the shaft of only 8.8 m/s. In general, tests have shown that the known cooled plain bearings cannot be used when the bearing sliding surface is exposed to peripheral speeds which reach 1 8 m/s or more.

The method of attaching the corrosionprotection tube 1 6 on the bearing bush 10 is relatively simple. For this purpose, the bearing bush 10 can be supercooled and if necessary, the corrosion-protection tube 1 6 can be heated up and drawn onto the bearing bush 10. When the temperatures are equalised, a firm leak-proof fit of the corrosion-protection tube 1 6 on the bearing bush 10 is obtained and a correspondingly leakproof closing-off of the cooling grooves 11 from outside and from the lubricant inlet bore 12, 1 2'.

Modifications are possible in relation to the example shown in Figures 1 to 3: For example, the corrosion-protection tube 1 6 is not needed if coolant which is not expected to cause corrosion of the bearing holders 1 7 is used, for example when oil, air or non-corrosive gases are used as the coolant. The cross-sectional shape of the cooling grooves 11 can be modified to correspond to the particular use. Trapezoidal, triangular, semi-circular and suchlike crosssectional shapes may be used for the cooling channels 11. Instead of the helical guidance shown in Figure 2, the coolant channels 11 can also extend tangentially, axially or in the form of meanders.

In the second embodiment illustrated in Figurres 4 to 6, the positively cooed plain bearing is composed of two semi-cylindrical haif-shells 21 and 22. Each of these two half-shells 21 and 22 has its own coolant passage 23 and 24 respectively, with its own coolant inlet 25 and 26 respectively, and its own coolant outlet 27 and 28 respectively, the corresponding feed and discharge channels also being provided in the parts 29 and 30 of the bearing block. Moreover, one half-shell 21 is also provided with the lubricant inlet bore 32 which is connected to a corresponding lubricant feed channel 33 in the part 29 of the bearing block. As shown in Figure 5, the coolant channels or coolant grooves 34, which extend axially in the form of meanders, are arranged in such a way that they are sealed off from the lubricant inlet bore 32 and are connected only to the coolant inlet 25 and the coolant outlet 27.

As in the example of Figures 1 to 3, to protect the valuable bearing holder 31 against corrosion, each half-shell 21 and 22 can be provided with a semi-cylindrically curved corrosion-protection plate 35 and 36 respectively. In principle, these corrosion-protection plates 35, 36 could be separate from the half-shells 21 and 22 and only inserted into the bearing holder 31. However, this would make it more difficult to assemble the bearing, and it is therefore recommended to attach the corrosion-protection plates 35 and 36 to the respective half-shells 21,22 by riveting or spot-welding. The corrosion-protection plates 35 and 36 are pressed sealingly against the particular half-shells 21 and 22 respectively, by pressing together the parts 29 and 30 of the bearing block.

The corrosion-protection plate 36 has the appropriate connecting bores for the coolant inlet 26 and the coolant outlet 28 respectively, to and from the coolant channels 34 of the bearing halfshell 22. In addition, the corrosion-protection plate 35 also has a through-bore to the lubricant inlet bore 32.

As shown in Figure 6, variations as regards the arrangement of the coolant channels 34 are possible even in this exemplary embodiment, and thus, in the example of Figure 6, the coolant channels 34 are arranged in the form of meanders in the peripheral direction of the half-shell 22. The position of the coolant inlet 25 and 26 respectively, and the coolant outlet 27 and 28 respectively, is to be arranged to accord with the particular circumstances and is indicated only diagrammatically in Figures 4 to 6.

In both embodiments, the coolant passage formed by means of the coolant channels 11 and 34 respectively, can be connected outside the bearing to the lubrication system. However, in this case, the lubrication system must operate with liquid or gaseous lubricant and must contain a lubricant pump which generates a lubricant pressure sufficient for cooling purposes and which has sufficient delivery capacity. In such a case, the cooling system can be connected in parallel to the lubrication system outside the bearing, that is to say upstream of the coolant inlet 14 and 25, 26 respectively and downstream of the coolant outlet 1 5 and 27, 28 respectively. There can be inserted, if appropriate, into this parallel connection a valve which makes it possible to switch the cooling system on and off and possibly also makes it controllable in terms of the quantity of coolant flowing through.

Claims

1. A plain bearing having a shell provided with channels through which liquid or gaseous coolant is guided, and providing positive guidance of the coolant through at least one coolant passage which is formed by the coolant channels, is selfcontained, is sealed off within the bearing from a lubrication system of the bearing and extends from a coolant intlet to a coolant outlet.

2. A bearing according to Claim 1, wherein the coolant inlet and the coolant outlet are likewise provided, separately from the lubrication system of the bearing, on or in a holder of the bearing.

3. A bearing according to Claim 1 or 2, wherein the coolant passage is connected to the lubrication system or is connectable thereto selectively.

4. A bearing according to Claim 3, wherein the coolant passage is connected to the lubrication system in the manner of a by-pass.

5. A bearing according to Claim 3, wherein the coolant passage is connectable to the lubrication selectively by means of a valve.

6. A bearing according to any one of Claims 1 to 5, wherein the coolant passage formed by the coolant channels has cross-sectional area of substantially the same size over its entire length.

7. A bearing according to any one. of Claims 1 to 6, wherein the coolant channels extend helically, tangentially, axially or in the form of meanders.

8. A bearing according to any one of Claims 1 to 7, wherein the coolant channels have trapezoidal, rectangular or semi-circular crosssection.

9. A plain bearing constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings.

1 0. A drive including a bearing according to any one of the preceding claims.

9. A bearing according to any one of Claims 1 to 8, wherein the shell is formed by part-shells, the coolant channels of each part-shell forming their own self-contained coolant passages.

10. A bearing according to any one of Claims 1 to 9, wherein the coolant channels are cut as grooves into the outer peripheral surface of the bearing shell or part-shell.

11. A bearing according to Claim 10, wherein attached to the outer side of the bearing shell or part-shell is a shell element which covers sealingly the coolant channels designed as grooves and which has passages for the coolant inlet and coolant outlet.

12. A bearing according to Claim 11, wherein the bearing shell is in the form of a bush, and the shell element covering the coolant channels sealingly is a thin-walled corrosion-protection tube shrunk onto the outer side of the bearing bush.

13. A bearing according to Claim 11, wherein the shell is formed by part-shells, and the shell element covering the coolant channels sealingly is a relatively thin corrosion-protection plate which is attached to the outer surface of each part-shell and which is curved according to the outer surface of the part shell.

14. A bearing according to Claim 13, wherein the corrosion-protection plate is attached to the part-shell by riveting or spot-welding.

1 5. A plain bearing constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings.

16. A drive including a bearing according to any one of the preceding claims.

New claims or amendments to claims filed on 3 Aug 1983.

Superseded claims all.

New or amended claims:

1. A plain bearing having a shell provided with channels through which liquid or gaseous coolant is guided, and providing positive guidance of the coolant through at least one coolant passage which is formed by the coolant channels, is selfcontained, is sealed off within the bearing from a lubrication system of the bearing and extends from a coolant inlet to a coolant outlet, the coolant channels extending helically, tangentially or axially.

2. A bearing according to Claim 1 ,wherein the coolant inlet and the coolant outlet are likewise provided, separately from the lubrication system of the bearing, on or in a holder of the bearing.

3. A bearing according to Claim 1 or 2, wherein the shell is formed by part-shells, the coolant channels of each part-shell forming their own selfcontained coolant passages.

4. A bearing according to any one of Claims 1 to 3, wherein the coolant channels are cut as grooves into the outer peripheral surface of the bearing shell or part-shell.

5. A bearing according to Claim 4, wherein attached to the outer side of the bearing shell or part-shell is a shell element which covers sealingly the coolant channels designed as grooves and which has passages for the coolant inlet and coolant outlet.

6. A bearing according to Claim 5, wherein the bearing shell is in the form of a bush, and the shell element covering the coolant channels sealingly is a thin-walled corrosion-protection tube shrunk onto the outer side of the bearing bush.

7. A bearing according to Claim 5, wherein the shell is formed by part-shells, and the shell element covering the coolant channels sealingly is a relatively thin corrosion-protection plate which is attached to the outer surface of each part-shell and which is curved according to the outer surface of the part shell.

8. A bearing according to Claim 7, wherein the corrosion-protection plate is attached to the partshell by riveting or spot-welding.