Self-lubricating sliding block and preparation method and application thereof

Abstract

The application discloses a self-lubricating sliding block and a preparation method and application thereof. The preparation raw material of the self-lubricating sliding block comprises 40-70 parts by weight of polyethylene resin and 40-60 parts by weight of lubricating oil; the weight average molecular weight of the polyethylene resin is 6-9*10 6 g / mol; and the particle size is 200-300 meshes. The self-lubricating sliding block formed by the specific polyethylene resin and the lubricating oil has good lubricating effect and long service life. The application further provides the preparation method and application of the self-lubricating sliding block.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and specifically relates to a self-lubricating slider, its preparation method, and its application. Background Technology

[0002] As a key functional component of CNC machine tools, rolling linear guide pairs mainly consist of guide rails, sliders, and rolling elements, playing a role in bearing and guiding moving parts in mechanical transmission. Due to their advantages such as high positioning and motion accuracy, low friction, smooth movement, and improved machine tool and machinery efficiency, rolling linear guide pairs have become one of the key basic components of precision CNC equipment. The accuracy retention of rolling linear guide pairs mainly depends on wear resistance, preload, and dimensional stability, which to some extent reflects their lifespan. Wear resistance is related to factors such as material matching, stress, machining accuracy, lubrication method, and installation method. Furthermore, the service life of rolling linear guide pairs directly affects the lifespan of machine tools and the cost of finished product processing.

[0003] To extend the service life of rolling linear guide pairs, lubrication is typically required in the industry to reduce friction. Currently, the two most common lubrication methods for rolling linear guide pairs are grease lubrication and oil lubrication. Both methods require the machine tool lubrication system or manual intervention to add grease or lubricating oil periodically and in measured quantities. While these methods provide lubrication, they increase costs and can lead to waste due to over-supply. Furthermore, the discharge of lubricating grease or oil causes environmental pollution.

[0004] To further optimize the lubrication effect, self-lubricating sliders have been attempted in traditional techniques; however, the lubrication effect of self-lubricating sliders used in traditional techniques is poor, and the manufacturing efficiency is low. Summary of the Invention

[0005] This invention aims to at least solve the problems of poor lubrication effect, frequent lubrication requirements, and low manufacturing efficiency of self-lubricating sliders in the prior art. Therefore, this invention provides a self-lubricating slider.

[0006] The present invention also provides a method for preparing the above-mentioned self-lubricating slider.

[0007] The present invention also provides applications of the above-mentioned self-lubricating slider.

[0008] The first aspect of the present invention provides a self-lubricating slider, wherein the raw materials for preparing the self-lubricating slider include 40-70 parts by weight of polyethylene resin and 40-60 parts by weight of lubricating oil; The weight-average molecular weight of the polyethylene resin is 6~9×10. 6 g / mol; particle size is 200~300 mesh.

[0009] The technical solution of the self-lubricating slider of the present invention has at least the following beneficial effects: This invention has discovered that a self-lubricating slider made solely from polyethylene resin and lubricating oil has excellent lifespan and lubrication performance, comparable to or even better than traditional self-lubricating sliders.

[0010] In existing technologies, the weight-average molecular weight of ultra-high molecular weight polyethylene resin refers to polyethylene resin with a molecular weight greater than 1 million. This does not fully meet the lifespan and lubrication performance requirements for self-lubricating sliders used in CNC machine tools. Therefore, this invention selects a weight-average molecular weight of 6~9×10⁻⁶. 6 A polyethylene resin in the range of g / mol was used, and lubricating oil was added to the polyethylene resin to improve its service life and lubrication performance.

[0011] This invention has found that the particle size of polyethylene resin has a significant impact on the microstructure and macroscopic properties of the resulting self-lubricating slider. Within the above range, a self-lubricating slider with high density can be obtained, and the raw material cost and preparation process cost are controllable. Specifically, the larger the particle size, the greater the porosity of the resulting self-lubricating slider, while the smaller the particle size, the easier it is to agglomerate during the preparation process, and the higher the cost.

[0012] According to some embodiments of the present invention, the weight-average molecular weight of the polyethylene resin is 6.5~8.5×10⁻⁶. 6 g / mol. For example, it could be 6.5 × 10⁻⁶. 6 g / mol, 7×10 6 g / mol, 7.5×10 6 g / mol, 8×10 6 g / mol, 8.5×10 6 g / mol; or a range of values ​​consisting of any two of the above points. Within the above range, the self-lubricating slider exhibits superior lifespan and lubrication performance.

[0013] According to some embodiments of the present invention, the polyethylene resin has a particle size of 250 mesh.

[0014] The particle size representation in this invention corresponds to the mesh size of a sieve. For example, 250 mesh means that the D50 particle size of the polyethylene resin is 61 μm.

[0015] According to some embodiments of the present invention, the lubricating oil is an industrial grease.

[0016] According to some embodiments of the present invention, the lubricating oil is a semi-fluid guide rail grease.

[0017] According to some embodiments of the present invention, the mass ratio of the polyethylene resin to the lubricating oil is 50~60:45~55.

[0018] According to some embodiments of the present invention, the mass ratio of the polyethylene resin to the lubricating oil is 1:0.7 to 1.25. Specifically, it can be 1:0.7, 1:0.75, 1:0.8, 1:0.82, 1:0.85, 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1, 1:1.15, 1:2, 1:1.22, 1:1.25; or a range of values ​​consisting of any two of the above points.

[0019] According to some embodiments of the present invention, the lifespan of the self-lubricating slider is ≥20,000 kilometers. For example, it can be 21,000 kilometers, 21,500 kilometers, 22,000 kilometers, 22,500 kilometers, 23,000 kilometers, 23,500 kilometers, or 24,000 kilometers; or a range of values ​​consisting of any two of the above points.

[0020] According to some embodiments of the present invention, no problems of burning or oil shedding occurred during the service life of the self-lubricating slider.

[0021] A second aspect of the present invention provides a method for preparing the self-lubricating slider described in the first aspect of the present invention, the method comprising the following steps: The polyethylene resin is heat-treated to sinter and mold it, and the resulting heat-treated product is then impregnated with lubricating oil under negative pressure.

[0022] The preparation method described in this invention has the following beneficial effects: This invention immerses heat-treated ultra-high molecular weight polyethylene resin powder in lubricating oil under negative pressure, which facilitates the full wetting of the lubricating oil by the heat-treated product, improves the uniformity of the distribution of the lubricating oil in the polyethylene resin after molding, and greatly shortens the wetting time between the heat-treated product and the lubricating oil; it solves the problems of poor lubrication effect and low preparation efficiency of self-lubricating sliders in traditional technology.

[0023] According to some embodiments of the present invention, the temperature of the heat treatment is 250~270°C. For example, it can specifically be 250°C, 255°C, 260°C, 265°C, 270°C; or a range of values ​​consisting of any two of the above points.

[0024] According to some embodiments of the present invention, the heat treatment holding time is 18 to 25 minutes. For example, it can be 18 minutes, 20 minutes, 22 minutes, 24 minutes, or 25 minutes; or a range of values ​​composed of any two of the above points.

[0025] According to some embodiments of the present invention, the pressure of the oil-absorbing impregnation is -90 to -100 kPa. For example, it can be -95 kPa. This pressure value is calculated with standard atmospheric pressure as zero.

[0026] According to some embodiments of the present invention, the oil absorption and soaking time is 20-30 minutes. For example, it can be 25 minutes.

[0027] The third aspect of the present invention provides the application of the self-lubricating slider described in the first aspect of the present invention on a CNC machine tool.

[0028] The present invention has the following beneficial effects regarding the aforementioned application: The application of the self-lubricating slider provided by the present invention on CNC machine tools can ensure continuous lubrication of the rolling linear guide pair, extend its service life, eliminate the need for periodic addition of lubricating grease (or reduce the frequency), reduce the labor, material and time costs of daily maintenance, and at the same time, there is virtually no oil emission, which can reduce environmental pollution.

[0029] According to some embodiments of the present invention, the CNC machine tool includes a rolling linear guide pair.

[0030] The rolling linear guide pair includes a guide rail, a slider, and rolling elements; The slider includes the self-lubricating slider described in the first aspect of the present invention.

[0031] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below, but the implementation of the present invention is not limited thereto.

[0033] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0034] Polyethylene resin A, with a weight-average molecular weight of 6 × 10⁻⁶ 6 g / mol, particle size 200 mesh; Polyethylene resin B has a weight-average molecular weight of 7 × 10⁻⁶. 6 g / mol, particle size 200 mesh; Polyethylene resin C, with a weight-average molecular weight of 8 × 10⁻⁶. 6 g / mol, particle size 200 mesh; Polyethylene resin D, with a weight-average molecular weight of 9 × 10⁻⁶. 6 g / mol, particle size 200 mesh; Polyethylene resin E, with a weight-average molecular weight of 8 × 10⁻⁶. 6 g / mol, particle size 300 mesh; Polyethylene resin F, with a weight-average molecular weight of 5 × 10⁻⁶.6 g / mol, particle size 200 mesh; Polyethylene resin G, with a weight-average molecular weight of 8 × 10⁻⁶. 6 g / mol, particle size 100 mesh; All of the above-mentioned polyethylene resins are commercially available; as long as they meet the requirements of GB / T 11115-2009 for first-class or superior grade injection-molded polyethylene resins, comparable technical effects can be obtained.

[0035] Example 1 Example 1 provides a self-lubricating slider, the raw materials for which the self-lubricating slider is prepared are as follows: Polyethylene resin C is 50 parts by weight; lubricating oil is 50 parts by weight; the lubricating oil is a semi-fluid guide rail grease (Sinopec Lubricating Oil Co., Ltd., No. 000).

[0036] In this example, the self-lubricating slider is prepared as follows: Polyethylene resin was heat-treated at 260℃ for 20 minutes. The resulting heat-treated product was then impregnated with lubricating oil under negative pressure. The impregnation pressure was -90~-100kPa (equivalent technical effects can be obtained within this range; in this example, the initial pressure was -95kPa), and the impregnation time was 20~30 minutes (equivalent technical effects can be obtained within this range; in this example, 25 minutes was selected).

[0037] Examples 2-8 Examples 2-8 each provide a self-lubricating slider, prepared using the same method as in Example 1, and the formulations are shown in Table 1.

[0038] Table 1. Amounts (parts by weight) of raw materials used in Examples 1-8 project Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Polyethylene resin C 50 40 60 70 50 50 50 50 Lubricating oil (same as in Example 1) 50 50 50 50 40 45 55 60 Examples 9-13 Examples 9-13 each provide a self-lubricating slider, prepared in the same way as in Example 1, and the formula is shown in Table 2.

[0039] Table 2. Amounts (parts by weight) of raw materials used in Examples 1, 9-13 project Example 1 Example 9 Example 10 Example 11 Example 12 Polyethylene resin A - 50 — — — Polyethylene resin B - — 50 — — Polyethylene resin C 50 Polyethylene resin D - — — 50 — Polyethylene resin E - — — — 50 Polyethylene resin F - — — — — Lubricating oil (same as in Example 1) 50 50 50 50 50 Comparative Example 1 Comparative Example 1 provides a self-lubricating slider, which differs from Example 1 in that: In this example, the amount of polyethylene resin used is 30 parts; the amount of lubricating oil (same as in Example 1) is 50 parts.

[0040] Comparative Example 2 Comparative Example 2 provides a self-lubricating slider, which differs from Example 1 in that: The polyethylene resin used is polyethylene resin F.

[0041] Comparative Example 3 Comparative Example 3 provides a self-lubricating slider, which differs from Example 1 in that: The polyethylene resin used is polyethylene resin G.

[0042] Performance testing The self-lubricating slider prepared according to the specific embodiments was subjected to performance testing. The test method was as follows: under room temperature conditions, the slider was preloaded with 3~5% of the rated dynamic load (ball bearing type, about 15kN), the linear running speed was 1.5m / s, the running stroke was 2m, and the slider was continuously run back and forth. There was no other lubricating grease on the guide rail raceway surface, and the lubrication was provided only by the self-lubricating slider of the present invention.

[0043] Lubrication performance: Under the above test conditions, observe whether the self-lubricating slider is burned (burned and blackened) or de-oiled during the test.

[0044] Lifespan: Under the above test conditions, with no other lubricating grease on the guide rail raceway surface and only lubrication provided by the self-lubricating slider of this invention, the running-in mileage can exceed 20,000 kilometers, and there is no peeling or damage on the guide rail raceway surface (the criterion for judging lifespan).

[0045] The test results of specific embodiments of the present invention are shown in Table 3: Table 3 Test data for specific implementation methods project Lubrication performance life Example 1 No burns, no degreasing 23,720 kilometers Example 2 No burns, no degreasing 21,030 kilometers Example 3 No burns, no degreasing 22,380 kilometers Example 4 No burns, no degreasing 21,420 kilometers Example 5 No burns, no degreasing 21,790 kilometers Example 6 No burns, no degreasing 23,040 kilometers Example 7 No burns, no degreasing 23,370 kilometers Example 8 No burns, no degreasing 21,560 kilometers Example 9 No burns, no degreasing 21,870 kilometers Example 10 No burns, no degreasing 23,110 kilometers Example 11 No burns, no degreasing 21,100 kilometers Example 12 No burns, no degreasing 23,780 kilometers Comparative Example 1 Severe burns, degreasing 19,350 kilometers Comparative Example 2 Severe burns, degreasing 19,270 kilometers Comparative Example 3 Severe burns, degreasing 19,090 kilometers Comparing Examples 1-4, it can be seen that, keeping the amount of lubricating oil constant, the service life of the resulting self-lubricating slider shows a trend of first increasing and then decreasing as the amount of polyethylene resin increases.

[0046] Comparative Examples 5-8 show that, with the amount of polyethylene resin remaining constant, the lifespan of the self-lubricating slider first increases and then decreases as the amount of lubricating oil increases.

[0047] As can be seen from Examples 1 to 8, when the mass ratio of polyethylene resin to lubricating oil is around 1:0.9 to 1.1, the lifespan of the resulting self-lubricating slider is significantly better.

[0048] As can be seen from Example 1 and Comparative Example 1, when the ultra-high molecular weight resin is 50-60 parts and the lubricating oil is 45-55 parts, the effect is better than that outside this range.

[0049] Comparing the results of Examples 1, 9-11, and Comparative Example 2, it can be seen that when other conditions remain unchanged, the lifespan of the self-lubricating slider first increases and then decreases with the increase of the weight-average molecular weight of polyethylene resin; and in the range of 7-8 × 10⁻⁶... 6Peak values ​​appear in or near the g / mol range; however, if the range exceeds the requirements of this invention, a significant drop in performance will occur.

[0050] Comparing the results of Example 1, Example 12 and Comparative Example 3, it can be seen that within the scope of the present invention, increasing the particle size of polyethylene resin slightly improves the lifespan of the self-lubricating slider, but it exceeds the scope required by the present invention, and its lifespan drops drastically, and it is prone to failure problems such as burning and oil depletion.

[0051] In summary, within the scope provided by this invention, the resulting self-lubricating slider has high safety, lubricity, and service life, and is expected to be widely used in CNC machine tools.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A self-lubricating slider, characterized in that, The raw materials for preparing the self-lubricating slider include 40-70 parts by weight of polyethylene resin and 40-60 parts by weight of lubricating oil. The weight-average molecular weight of the polyethylene resin is 6~9×10. 6 g / mol; particle size is 200~300 mesh.

2. The self-lubricating slider according to claim 1, characterized in that, The mass ratio of the polyethylene resin to the lubricating oil is 50~60:45~55.

3. The self-lubricating slider according to claim 1, characterized in that, The mass ratio of the polyethylene resin to the lubricating oil is 1:0.7~1.

25.

4. The self-lubricating slider according to claim 1, characterized in that, The weight-average molecular weight of the polyethylene resin is 6.5~8.5×10⁻⁶. 6 g / mol.

5. The self-lubricating slider according to claim 1, characterized in that, The lubricating oil is an industrial lubricating grease; Preferably, the lubricating oil is a semi-fluid guide rail grease.

6. A method for preparing a self-lubricating slider as described in any one of claims 1 to 5, characterized in that, The preparation method includes the following steps: The polyethylene resin is heat-treated to sinter and mold it, and the resulting heat-treated product is then impregnated with the lubricating oil under negative pressure.

7. The preparation method according to claim 6, characterized in that, The heat treatment temperature is 250~270℃; And / or, the heat treatment holding time is 18~25 min.

8. The preparation method according to claim 6, characterized in that, The pressure of the oil-absorbing and impregnating gas is -90~-100kPa.

9. The preparation method according to claim 6, characterized in that, The oil absorption and wetting time is 20-30 minutes.

10. The application of a self-lubricating slider as described in any one of claims 1 to 5 in a CNC machine tool.