Can Graphite Bushings Be Lubricated with Oil?

In the field of industrial machinery, graphite bushings are an essential self-lubricating component that has long attracted the attention of technicians, particularly regarding their lubrication methods. A common question that arises is whether graphite bushings can be lubricated with oil, and there are some misconceptions surrounding this topic.

First and foremost, it is important to clarify that graphite bushings can indeed be lubricated with both oil and grease. Some mistakenly believe that applying grease to graphite bushings will disrupt the solid lubricating film that forms during operation, leading to lubrication failure or a decline in performance. However, this is not the case. When lubricating grease is applied, it works in conjunction with the solid lubricating film made of graphite to enhance the performance of the bushings significantly.

Graphite Bushings

Zhejiang Mingxu has conducted detailed bench tests, providing compelling evidence for this point. The test results show that the friction coefficient of graphite bushings under dry friction conditions is 0.14, while under lubricated conditions, it drops significantly to 0.03. In terms of the maximum PV value (N/mm²·m/s), it increases from 1.65 under dry friction to 3.25 under lubricated conditions. Regarding the maximum linear speed, it is 0.5 m/s under dry friction but can reach 1 m/s under lubricated conditions.

These empirical data clearly demonstrate that lubricating graphite bushings with oil does not compromise their original performance; instead, it significantly improves it. The result is a lower friction coefficient, higher load-bearing capacity, faster sliding speed, and a longer service life.

Addressing concerns about lubricating grease potentially destroying the solid lubricating film, it is true that the original solid lubricating film may not maintain its full integrity after oil lubrication. However, it is important to note that the combination of lubricating grease and the solid graphite lubricant forms a new composite lubricating film that performs even better than the original single solid lubricating film. Furthermore, even if the lubricating grease is depleted, the graphite bushing can quickly regenerate a new solid lubricating film, ensuring continued effective lubrication.

Graphite Plates

Zhejiang Mingxu Machinery Manufacturing Co., Ltd., a leader in the field of copper alloy components and self-lubricating bearings, has over a decade of research and development experience in production. We are dedicated to providing customers with high-quality products and expert technical support. If you have any questions about our products or technologies, please feel free to contact us at [email protected].