Wear-resistant polymer-based bearing bush and production process thereof

Abstract

The invention discloses a wear-resistant polymer-based bearing bush which comprises a metal layer, a middle layer and a sliding layer, the middle layer is of a porous structure, the sliding layer is made of a polymer composite material, and the polymer composite material is formed on the middle layer through injection molding. The method has the advantages of good wear resistance, simple process, high operation efficiency and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing bushes, and in particular to a wear-resistant polymer-based bearing bush and a production process. Background Art

[0002] Polymer-based bearings are an important component mainly used in hydro-turbine generators or wind turbine gearboxes. In the existing technology, most bearings adopt a metal + polymer structure. First, a porous structure is sintered on a metal substrate or a connecting structure is processed on a metal substrate. Its wear resistance is poor, and the polymer material powder is combined with the metal substrate through a sintering and pressing process. The preparation process is relatively complicated, and the sintering and pressing of polymer powder will cause problems such as uneven powder mixing, poor sintering plasticization, and the presence of pores, which affect product performance and make it difficult to achieve efficient production.

[0003] For example, in the Chinese patent with publication number CN20050803A: Water-lubricated metal plastic bearing and production method, it is necessary to first prepare a metal wire pad from the metal wire, then mold and sinter the mixture powder of polytetrafluoroethylene, fiber, lead powder, etc. with the metal wire pad to obtain a blank, and finally braze the blank on the metal base. It also has the above-mentioned problems. Summary of the Invention

[0004] In order to overcome the above-mentioned deficiencies of polymer-based bearings in the prior art, the present invention provides a wear-resistant polymer-based bearing having the advantages of good wear resistance, simple process, high operating efficiency, etc.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A wear-resistant polymer-based bearing bush comprises a metal layer, an intermediate layer and a sliding layer. The intermediate layer is a porous structure, and the sliding layer is made of a polymer composite material. The polymer composite material is formed on the intermediate layer by injection molding.

[0006] Preferably, the porosity of the intermediate layer is 30%-80%.

[0007] Preferably, the porosity of the intermediate layer is more preferably 45%-60%.

[0008] Preferably, the metal layer is made of an alloy consisting of one or more of low carbon steel, stainless steel, aluminum and copper.

[0009] Preferably, the sliding layer includes one or more of molybdenum disulfide, polytetrafluoroethylene, carbon fiber powder, aramid powder, and silicon carbide.

[0010] Preferably, the melt viscosity of the polymer composite material is 5-100 g / 10 min.

[0011] Preferably, the melt viscosity of the polymer composite is more preferably 20 - 50 g / 10 min.

[0012] The present invention also discloses a production process of a wear-resistant polymer-based bearing bush, comprising the following steps: 1) Sinter a porous structure on a metal substrate to obtain a metal substrate with a porous structure; 2) Mix polymer materials and then put them into melting and mixing to obtain a polymer composite; 3) Put the polymer composite in step 2) into an injection molding device, put the metal substrate with a porous structure in step 1) into an injection mold, and injection mold on the surface of the metal substrate with a porous structure to obtain a bearing bush blank.

[0013] Preferably, the injection mold includes a front mold and a rear mold; a front mold positioning boss is provided on one side of the front mold, and a rear mold positioning groove adapted to the front mold positioning boss is provided on one side of the rear mold. In traditional molds, the bearing bush metal substrate is fixed by a mechanical fixing device. During the injection molding process, it is necessary to repeatedly open and release the fixing device to move the metal substrate between the upper and lower molds, and the operation is cumbersome, which affects the production efficiency. After the injection molding of the present invention, adsorption is cancelled, the operation is simple, and the mechanical device for fixing is cancelled.

[0014] Preferably, a magnetic adsorption plate is provided on the bottom surface of the rear mold.

[0015] Preferably, an injection port is provided on the front end face of the front mold.

[0016] The beneficial effects of the present invention are as follows: (1) A sliding layer is added in the present invention, so that the wear resistance is better; and the sliding layer is made of a polymer composite, and the polymer composite is formed on the intermediate layer by injection molding, which simplifies the production process and improves the operation efficiency; (2) The polymer materials are melted and mixed in the present invention, and a polymer composite (plastic particles) with uniform dispersion and excellent performance can be obtained, avoiding the problems of uneven mixing and poor plasticization of traditional powder materials during sintering. Further, the composite material is compounded on the metal substrate by an injection molding process. On the one hand, the injection molding process is fast and efficient, and batch production can be realized. On the other hand, the dimensional stability of the sliding layer can be ensured. The high pressure of injection molding can avoid the generation of pores in the sliding layer. At the same time, by controlling the melt viscosity of the material, it can be ensured that during the injection molding process, the melt fills the entire mold cavity under the action of the injection pressure, further ensuring the dimensional stability of the sliding layer and avoiding the generation of pores; (3) Positioning grooves and positioning bosses are distributed on the parting surface of the front and rear molds, which ensures the positioning of the front and rear molds and can also play an exhaust role during the injection molding process to reduce the generation of injection molding defects. (4) During the injection molding, the magnetic adsorption plate is used to maintain a strong adsorption and fixing effect on the metal substrate, and the adsorption is cancelled after the injection molding, and the operation is simple. Description of the Drawings

[0017] Figure 1 It is a schematic cross-sectional structure diagram of a wear-resistant polymer-based bearing bush of the present invention;

[0018] Figure 2 It is a schematic assembly diagram of an injection molding machine and an injection mold of the present invention;

[0019] Figure 3 It is a schematic cross-sectional structure diagram of the injection mold of the present invention;

[0020] Figure 4 It is a microscopic view of the product of the traditional sintering process of the present invention;

[0021] Figure 5 It is a microscopic view of the product of the injection molding process of Example 4 of the present invention.

[0022] In the figure: 1 is the sliding layer, 2 is the intermediate layer, 3 is the metal layer, 4 is the injection molding machine, 41 is the injection feeding bin, 42 is the injection barrel, 43 is the injection nozzle, 5 is the injection mold, 6 is the metal substrate with a porous structure; 5 is the injection mold, 51 is the front mold, 52 is the rear mold, 53 is the injection port, 54 is the magnetic attraction plate, 55 is the positioning boss, 56 is the positioning groove. Detailed implementation manners

[0023] The following further describes the present invention in conjunction with the accompanying drawings and specific embodiments.

[0024] In the present invention, polymers are conventionally referred to as compounds with a relative molecular mass as high as one thousand to several million in the art.

[0025] Example 1: As Figure 1 shown, a wear-resistant polymer-based bearing bush includes a metal layer 3, an intermediate layer 2, and a sliding layer 1. The intermediate layer has a porous structure. The sliding layer is made of a polymer composite material, and the polymer composite material is formed on the intermediate layer by injection molding. The porosity of the intermediate layer is 30%. The melt viscosity of the polymer composite material is 5 g / 10 min. The metal layer is made of low-carbon steel. The sliding layer includes polytetrafluoroethylene. In this embodiment, it can be sintered on the metal substrate in the form of metal powder, wire or mesh structure.

[0026] Example 2: A wear-resistant polymer-based bearing bush includes a metal layer, an intermediate layer, and a sliding layer. The intermediate layer has a porous structure. The sliding layer is made of a polymer composite material, and the polymer composite material is formed on the intermediate layer by injection molding. The porosity of the intermediate layer is 80%. The melt viscosity of the polymer composite material is 100 g / 10 min. The metal layer is made of stainless steel. The sliding layer includes molybdenum disulfide.

[0027] Example 3: A wear-resistant polymer-based bearing bush, comprising a metal layer, an intermediate layer and a sliding layer. The intermediate layer is a porous structure, and the sliding layer is made of a polymer composite material, which is formed on the intermediate layer by injection molding. The porosity of the intermediate layer is 45%. The melt viscosity of the polymer composite material is 20 g / 10 min. The metal layer is made of an aluminum alloy. The sliding layer includes carbon fiber powder.

[0028] Example 4: A wear-resistant polymer-based bearing bush, comprising a metal layer, an intermediate layer and a sliding layer. The intermediate layer is a porous structure, and the sliding layer is made of a polymer composite material, which is formed on the intermediate layer by injection molding. The porosity of the intermediate layer is 60%. The melt viscosity of the polymer composite material is 50 g / 10 min. The metal layer is made of an alloy of low-carbon steel and copper. The sliding layer includes aramid powder. Silicon carbide can also be used in this example.

[0029] This example also discloses a production process of a wear-resistant polymer-based bearing bush, comprising the following steps: 1) Sinter the porous structure on a metal substrate to obtain a metal substrate with a porous structure; 2) Mix the polymer materials evenly and then put them into melting and mixing to obtain a polymer composite material; 3) Put the polymer composite material in step 2) into an injection molding device, put the metal substrate with a porous structure in step 1) into an injection mold, and injection mold it on the surface of the metal substrate with a porous structure to obtain a bearing bush blank. In this example, by mixing the polymer materials evenly and then putting them into a twin-screw extruder, a polymer composite material (plastic particles) with uniform dispersion and excellent performance can be obtained, avoiding the problems of uneven mixing and poor plasticization of traditional powder mixing and sintering.

[0030] As Figure 2 and Figure 3 shown, the injection mold 5 includes a front mold 51 and a rear mold 52; a front mold positioning boss 55 is provided on one side of the front mold, and a rear mold positioning groove 56 adapted to the front mold positioning boss is provided on one side of the rear mold. A magnetic attraction plate 54 is provided on the bottom surface of the rear mold. An injection port 53 is provided on the front end surface of the front mold. The magnetic attraction plate is controlled by current, that is, it maintains a strong adsorption and fixing effect on the metal substrate during injection molding, and cancels the adsorption after injection molding. The operation is simple. The mechanical device for fixing is cancelled, and the upper and lower molds of the metal substrate can be controlled only by current, improving the operation efficiency.

[0031] Table 1 Example description

[0032] Combined with Figure 4 and Figure 5, It can be seen from the data that the friction and wear performance of the injection molding process in Example 4 is significantly better than that of the traditional process, and there are no pores.

[0033] The above are only the preferred embodiments of the present invention, and thus do not limit the patent protection scope of the present invention. Any equivalent transformation made by using the content of the specification and drawings of the present invention, directly or indirectly applied in other related technical fields, shall be included in the protection scope of the present invention by the same token.

Claims

1. A wear-resistant polymer-based bearing shell, characterized in that, It includes a metal layer, an intermediate layer and a sliding layer. The intermediate layer has a porous structure; the sliding layer is made of a polymer composite material, and the polymer composite material is formed on the intermediate layer by injection molding.

2. The wear-resistant polymer-based bearing shell according to claim 1, characterized in that, The porosity of the intermediate layer is 30%-80%.

3. The wear-resistant polymer-based bearing shell according to claim 1, characterized in that, The metal layer is composed of an alloy formed by one or more of low-carbon steel, stainless steel, aluminum, and copper.

4. A wear-resistant polymer-based bearing bush according to claim 1, characterized in that, The sliding layer includes one or more of molybdenum disulfide, polytetrafluoroethylene, carbon fiber powder, aramid powder, and silicon carbide.

5. The wear-resistant polymer-based bearing shell according to claim 1, wherein, The melt viscosity of the polymer composite material is 5-100 g / 10 min.

6. The wear-resistant polymer-based bearing shell according to claim 5, characterized in that, The melt viscosity of the polymer composite material is 20-50 g / 10 min.

7. A production process of a wear-resistant polymer-based bearing bush, characterized in that, It includes the following steps: 1) Sinter the porous structure on a metal substrate to obtain a metal substrate with a porous structure; 2) Mix the polymer materials and then put them into melting and mixing to obtain a polymer composite material; 3) Put the polymer composite material in step 2) into an injection molding device, put the metal substrate with a porous structure in step 1) into an injection mold, and injection mold it on the surface of the metal substrate with a porous structure to obtain a bushing blank.

8. The production process of a wear-resistant polymer-based bearing shell according to claim 7, characterized in that, The injection mold includes a front mold and a rear mold; a front mold positioning boss is provided on one side of the front mold, and a rear mold positioning groove adapted to the front mold positioning boss is provided on one side of the rear mold.

9. The production process of a wear-resistant polymer-based bearing shell according to claim 8, characterized in that, A magnetic attraction plate is provided on the bottom surface of the rear mold.

10. The production process of a wear-resistant polymer-based bearing shell according to claim 8, characterized in that, An injection port is provided on the front end face of the front mold.

Images