GB1559369A - Method of removing particles of abraded material from a plain bearing - Google Patents

Description

(54) A METHOD OF REMOVING PARTICLES OF ABRADED MATERIAL FROM A PLAIN BEARING (71) We, DORNIER SYSTEM G.m.b.H., a German limited liability company, of Postfach 1360, 7990 Friedrichshafen 1, Federal Republic of 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: This invention relates to a method of removing particles of abraded material from an oil-lubricated plain bearing by means of a magnet disposed at a location in the oil-flow path. The invention also relates to a bearing.

In the assembly and installation of heavy duty and high speed bearings, it is inevitable that component parts should come into mutual contact so that particles of metal are abraded. This is particularly the case when components are connected together or when fixing elements, for example screws. are screwed into place. This abraded metal can be neither blown out nor removed in anv other way. On the other hand. it is possible during assembly to ensure a degree of cleanliness such that no non-metallic dirt particles are present in the bearing.

During the starting up phase of a bearing, particles of abraded material are produced which pass into the lubricating oil. by which they are carried back into the bearing. The particles occasioned both during assembly and also by abrasion in the starting phase, enter the lubricating oil and when the bearing is operating they act abrasively and erode the bearing. Eroded bearings frequently do not have the effective life calculated for and required of them.

It is known to eliminate particles of abraded material from an oil lubricated bearing by sedimentation. For sedimentation of the particles in oil. there must be non-moving zones past which the particles are carried and into which they can enter. In this way, it is possible for particles of any granulation to be separated. In the case of small particles (for example smaller than 10 Rm), quite a long sedimentation time must be expected. But it is not always possible structurally to provide special sedimentation zones in a bearing system.

It is also known, by the provision of gap filters in the oil flow path. to eliminate metallic and non-metallic particles from flow. This applies only to relatively large particles (granules larger than 20 rum), since better filters are not available and would onlv result in flow losses.

It is also known to eliminate the magnetic particles from the oil by means of a magnet.

This principle has found application particu larly in a magnetic oil drain screw in engine construction.

The invention is based on the problem of removing particles of abraded material from a plain bearing, the components of which are at least partially of non-magnetic materials for example aluminium and copper.

According to this invention there is provided a method of removing particles of abraded material from an oil-lubricated plain bearing by means of a magnet disposed at a location in the oil flow path adjacent the bearing, wherein non-magnetic components of the bearing are completely coated with a magnetic coating before assembly of the bearing. Coatings of nickel or chrome have proved successful.

The invention can be applied to various bearings. For example. multiple area plain bearings and spirally grooved ball and socket bearings comprising a cup and a ball, may be mentioned.

The invention will now be described by way of example with reference to the drawings, in which: Figure 1 is a diagrammatic section through a spirally grooved ball and socket hearing; and Figure 2 is a diagrammatic section through a radial bearing.

Figure 1 shows the bearing of a spindle of an open-end spinning rotor, a housing 2 being of aluminium, a cooler 4 of copper, a ball 6 and the spindle 8 of steel. a cup 10 of a copper-beryllium alloy, and a screwthreaded fixing member 12 of brass. Thus the bearing has some components which are magnetic and some which are non-magnetic.

Figure 2 shows a radial bearing which has an aluminium housing 14, a seal 16 of brass, a steel shaft 18, and a bearing shell 20 of copper-beryllium. Thus both magnetic and non-magnetic materials are present.

When a bearing is assembled, for example the fixing member 12 is screwed in or the bearing shell 20 is pressed into the housing 14, both magnetic and non-magnetic particles are created. In operation, on starting up the bearing, magnetic and non-magnetic abrasion occurs between the bearing faces.

and the abraded material finds its way into the lubricating oil circuit 22, 24. As the oil flows around, the particles move through the bearing and lead to erosion of its sliding surfaces.

If a magnet 26 or 28 is located in the bearing, then magnetic particles of metal can be extracted from the flow of oil.

However, this onlv inconsiderably reduces the erosion of the sliding surfaces. since for example aluminium and copper particles remain in the flow of oil.

If however, all the components of the bearings are coated with a laver of for example nickel, then abraded material will be removed from the flow of oil before erosion can occur.

Such coating may be pure nickel or a hardenable nickel alloy (for example that known under the Trade mark "Kanigen").

Normally the hardenable nickel alloy is non-magnetic, and is nickel with a high percentage of phosphorus. The nickel alloy is subjected to a heat treatment at approx mately 290"C. during which nickel phosphite forms. The alloy acquires a hardness of about 1000 Vickers. At the same time there is a reduction in the proportion of phosphorus so that the nickel is able to release its magnetic effect. In the coating of bearing components such as bearing shells.

the heat treatment results in considerable hardness and resistance to abrasion. so that the use of "Kanigen" is advantageous for bearing shells, while for the other component parts a coating of pure nickel may be adequate.

In particular all non-magnetic components of the bearing are covered with a magnetic coating. Although this makes manufacture of the bearing as a whole more expensive. nevertheless in the case of a heavy duty bearing it does lead to an increase in effective life which is to be preferred to lower production cost.

WHAT WE CLAIM IS: 1. A method of removing particles of abraded material from an oil-lubricated plain bearing by means of a magnet disposed at a location in the oil flow path adjacent to the bearing, wherein nonmagnetic components of the bearing are completely coated with a magnetic coating before assembly of the bearing.

2. A method according to claim 1 wherein the magnetic coating is a layer of nickel or chromium or a hardened nickelphosphorus alloy.

3. A method according to claim 1 or claim 2 wherein a non-magnetic component is a bearing shell, or a bearing housing or housing part, or a mounting or fixing part, or other bearing part contacted by the lubricant oil.

4. An oil-lubricated plain bearing structure including a housing and bearing parts so disposed as to provide for an oil flow path, and a magnet disposed at a location in the flow path adjacent the bearing, wherein non-magnetic components of the structure are completely coated with a magnetic coating.

5. An oil-lubricating plain bearing structure constructed and arranged substantially as herein described and shown in the accompanying drawing.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. Figure 2 is a diagrammatic section through a radial bearing. Figure 1 shows the bearing of a spindle of an open-end spinning rotor, a housing 2 being of aluminium, a cooler 4 of copper, a ball 6 and the spindle 8 of steel. a cup 10 of a copper-beryllium alloy, and a screwthreaded fixing member 12 of brass. Thus the bearing has some components which are magnetic and some which are non-magnetic. Figure 2 shows a radial bearing which has an aluminium housing 14, a seal 16 of brass, a steel shaft 18, and a bearing shell 20 of copper-beryllium. Thus both magnetic and non-magnetic materials are present. When a bearing is assembled, for example the fixing member 12 is screwed in or the bearing shell 20 is pressed into the housing 14, both magnetic and non-magnetic particles are created. In operation, on starting up the bearing, magnetic and non-magnetic abrasion occurs between the bearing faces. and the abraded material finds its way into the lubricating oil circuit 22, 24. As the oil flows around, the particles move through the bearing and lead to erosion of its sliding surfaces. If a magnet 26 or 28 is located in the bearing, then magnetic particles of metal can be extracted from the flow of oil. However, this onlv inconsiderably reduces the erosion of the sliding surfaces. since for example aluminium and copper particles remain in the flow of oil. If however, all the components of the bearings are coated with a laver of for example nickel, then abraded material will be removed from the flow of oil before erosion can occur. Such coating may be pure nickel or a hardenable nickel alloy (for example that known under the Trade mark "Kanigen"). Normally the hardenable nickel alloy is non-magnetic, and is nickel with a high percentage of phosphorus. The nickel alloy is subjected to a heat treatment at approx mately 290"C. during which nickel phosphite forms. The alloy acquires a hardness of about 1000 Vickers. At the same time there is a reduction in the proportion of phosphorus so that the nickel is able to release its magnetic effect. In the coating of bearing components such as bearing shells. the heat treatment results in considerable hardness and resistance to abrasion. so that the use of "Kanigen" is advantageous for bearing shells, while for the other component parts a coating of pure nickel may be adequate. In particular all non-magnetic components of the bearing are covered with a magnetic coating. Although this makes manufacture of the bearing as a whole more expensive. nevertheless in the case of a heavy duty bearing it does lead to an increase in effective life which is to be preferred to lower production cost. WHAT WE CLAIM IS:

1. A method of removing particles of abraded material from an oil-lubricated plain bearing by means of a magnet disposed at a location in the oil flow path adjacent to the bearing, wherein nonmagnetic components of the bearing are completely coated with a magnetic coating before assembly of the bearing.

2. A method according to claim 1 wherein the magnetic coating is a layer of nickel or chromium or a hardened nickelphosphorus alloy.

3. A method according to claim 1 or claim 2 wherein a non-magnetic component is a bearing shell, or a bearing housing or housing part, or a mounting or fixing part, or other bearing part contacted by the lubricant oil.

4. An oil-lubricated plain bearing structure including a housing and bearing parts so disposed as to provide for an oil flow path, and a magnet disposed at a location in the flow path adjacent the bearing, wherein non-magnetic components of the structure are completely coated with a magnetic coating.

5. An oil-lubricating plain bearing structure constructed and arranged substantially as herein described and shown in the accompanying drawing.