Metal-backed plain bearing

Abstract

A bearing comprises a resin matrix filled with fluoropolymer, graphite, and other discrete particles of an additive material that is attached to a backing material. A method for manufacturing a bearing comprises depositing to a backing material a fluid polymer bearing material comprised of a resin matrix filled with fluoropolymer, various fillers, and discrete particles of an additive to form a continuous consolidated bearing material, and curing the lining material to bond the lining material onto the backing material.

Claims

1. A method for forming a plain bearing, comprising: providing a single layer metal substrate; leveling the single layer metal substrate to form a backing material; preparing a bearing lining material comprising a mixture of approximately 70 to 90% by volume of an epoxide thermoset resin, approximately 5 to 20% by volume of at least one fluoropolymer, and approximately 1 to 8% by volume of at least one other filler; depositing the bearing lining material directly onto the single layer metal substrate; and drying the bearing lining material to bond the bearing lining material directly onto the single layer metal substrate and to form a bearing lining material layer having a constant thickness; wherein the bearing lining material deposited directly onto the single layer metal substrate is free of solvent.

2. The method of claim 1, wherein the single layer metal substrate is a metal sheet in coil form, and wherein leveling comprises leveling by a straightening machine to form the backing material.

3. The method of claim 1, wherein the fluoropolymer comprises approximately 12% by volume of PTFE.

4. The method of claim 1, wherein the at least one other filler comprises approximately 2% by volume of graphite.

5. The method of claim 1, wherein the at least one fluoropolymer comprises PTFE.

6. The method of claim 1, wherein the at least one other filler comprises graphite.

7. The method claim 1, wherein the single layer metal substrate is placed on a vacuum table after being leveled and prior to depositing bearing lining material thereon.

8. The method of claim 1, wherein the method further comprises: leveling the bearing lining material after depositing the bearing lining material on the single layer metal substrate and prior to drying the bearing lining material.

9. The method of claim 1, wherein depositing the bearing lining material directly onto the single layer metal substrate comprises depositing the bearing lining material in an amount such that multiple layers of the at least one fluoropolymer and the at least one other filler are provided within the bearing lining material.

10. A method for forming a plain bearing, comprising: preparing a bearing lining material comprising a mixture of approximately 70 to 90% by volume of an epoxide thermoset resin, approximately 5 to 20% by volume of at least one fluoropolymer, and approximately 1 to 8% by volume of at least one other filler; depositing the bearing lining material directly onto a single layer metal substrate; and drying the bearing lining material to bond the bearing lining material directly onto the single layer metal substrate and to form a bearing lining material layer having a constant thickness; wherein the bearing lining material deposited directly onto the single layer metal substrate is free of solvent.

11. The method of claim 10, wherein the fluoropolymer comprises approximately 12% by volume of PTFE.

12. The method of claim 10, wherein the at least one other filler comprises approximately 2% by volume of graphite.

13. The method of claim 10, wherein the at least one fluoropolymer comprises PTFE.

14. The method of claim 10, wherein the at least one other filler comprises graphite.

15. The method claim 10, wherein the single layer metal substrate is placed on a vacuum table prior to depositing bearing lining material thereon.

16. The method of claim 10, wherein the method further comprises: leveling the bearing lining material after depositing the bearing lining material on the single layer metal substrate and prior to drying the bearing lining material.

17. The method of claim 10, wherein depositing the bearing lining material directly onto the single layer metal substrate comprises depositing the bearing lining material in an amount such that multiple layers of the at least one fluoropolymer and the at least one other filler are provided within the bearing lining material.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The present invention will be more clearly understood from a reading of the following description in conjunction with the accompanying exemplary figures wherein:

(2) FIG. 1A shows a cross-section of a bearing made using a prior art method;

(3) FIG. 1B shows a bearing manufacturing process according to an exemplary embodiment of a prior art method;

(4) FIG. 2 shows a plain bearing according to an exemplary embodiment of the present invention;

(5) FIGS. 3A and 3B show a bearing manufacturing process according to an exemplary embodiment of the present invention; and

(6) FIG. 4 shows a cross-section of a plain bearing according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION

(7) Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the accompanying attachments. Each example is provided by way of explanation of the invention, not as a limitation of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment of the invention can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations that come within the scope of the invention.

(8) FIG. 2 shows a plain bearing 200 having a metal backing layer 210 and a bearing material layer 220. The bearing material layer 220 can be a continuous consolidated structure comprising a curable resin mixed with a combination of fillers and discrete particles of additive materials.

(9) The type of resin used can comprise any curable resin suitable for mixing with the fillers and additives. The resin used can be curable by use of air, heat, chemical reaction, or radiation. In one exemplary embodiment, the resin is an epoxide thermoset resin.

(10) The fillers used can include fluoropolymers, such as polytetrafluoroethylene (PTFE), mono fluoro alkoxy, and fluorinated ethylene propylene; themoplastics, such as polyetheretherketone, polyphenylenesulphide, and polyamide; graphites or carbons, diamond powder, irregular carbon black, and fullerenes; strengthening fillers, such as calcium fluoride, barium sulfate, micro glass spheres, and ceramic powder; lubricating minerals, such as molybdenum disulphide and tungsten disulphide; lubricating fluids, such as silicone oils; fibers, such as carbon, glass, polymer, and PTFE; and fabrics or meshes, such as carbon, glass, polymer, and PTFE. In one embodiment, any amount or number of fillers can be included in the bearing material layer 220 so long as enough resin is present to form a continuous, consolidated bearing material layer 220.

(11) The additive material can comprise any material suitable for incorporation into the filled resin such that the resulting bearing material layer 220 is disposed upon the backing material and operable to withstand the processing temperatures used to consolidate the bearing material layer and the mechanical loadings of the application. The additive material can include amine-based curing agents, such as, but not limited to, amines, anhydrides, acrylic copolymers (e-g., Disperbyk 2070) and boric acid esters (e.g., Byk W909). In a preferred embodiment, any amount of additive material can be included in the bearing material layer 220 so long as enough resin is present to form a continuous consolidated layer.

(12) The metal backing layer 210 can comprise any material operable to support the bearing material layer 220 and withstand the processes of sintering the bearing material layer 220. In an embodiment, the metal backing layer 210 of the bearing can comprise a metal strip, e.g. low carbon steel strip. As yet another alternative, the metal backing layer 210 can comprise a metal strip being nickel or copper plated or covered with bronze sintered powder thereon to enhance adhesion of the bearing material layer 220, or a metallic mesh.

(13) FIGS. 3A and 3B show an exemplary method for manufacturing plain bearings. First, a metal substrate 300, such as a steel sheet in coil form, is leveled by a straightening machine 302 to form the backing material 304.

(14) An exemplary viscous bearing lining 310 can be prepared with a mixture of approximately 70 to 90% by volume of an epoxide thermoset resin, approximately 5 to 20% by volume of at least one fluoropolymer (e.g. approximately 12% by volume of PTFE), and approximately 1 to 8% of at least one other filler (e.g. 2% by volume of graphite), together with above-mentioned processing additive materials. The properties of the resulting bearing material layer can be tailored to suit different operating conditions by changing the amounts and types of fillers, as known to one of ordinary skill in the art.

(15) The leveled metal substrate 304 can be kept flat by placing it on a vacuum table 350. In this position, the bearing material 310 is deposited onto the metal substrate 304 by gravity and is spread using a doctor knife 350, which is accurately positioned to give a constant thickness. The leveled metal substrate 304, which is now coated by the bearing material layer 310, is carried by a conveyor belt 330 through an oven 320 in order to dry and cross-link the bearing material layer 310 and ensure a sufficient bonding of the layer onto the metal substrate 304. The bearing material layer 310 can be optimized by adjusting thickness and/or temperature during curing to achieve desired properties.

(16) FIG. 4 shows a cross-sectional view of a plain bearing. According to the exemplary process above, a viscous bearing layer 420 can be formed by mixing an epoxide thermoset resin 400 with a bearing material 410 that includes appropriate fillers, and additive materials. The bearing layer 420 can be cured to the metal backing layer 430, to form a plain bearing.

(17) The embodiments described above are intended to be exemplary. One skilled in the art recognizes that numerous alternative components and embodiments that may be substituted for the particular examples described herein and still fall within the scope of the invention.

(18) For the purposes of this specification, unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification are to be understood as being modified in all instances by the term about. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification are approximations that can vary depending upon the desired properties sought by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

(19) Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting h r n the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein, and every number between the end points. For example, a stated range of 1 to 10 should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, e.g., 1 to 8.3, and ending with a maximum value of 10 or less, e.g., 5.5 to 10, as well as all ranges beginning and ending within the end points, e-g., 2 to 9, 3 to 8, 3 to 9, 4 to 7, and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 contained within the range. Additionally, any reference referred to as being incorporated herein is to be understood as being incorporated in its entirety.

(20) It is further noted that, as used in this specification, the singular forms a an, and the include plural referents unless expressly and unequivocally limited to one referent.