Selection of oil-free self-lubricating bearings.

To overcome the lubrication challenges associated with mechanical equipment operating under high temperatures, low speeds, heavy loads, dust, water exposure, shock, and vibration, Mingxu Bearing offers a reliable solution—oil-free self-lubricating bearings.

Specifically designed for the foundry industry, these bearings feature strategically positioned perforations on the metal friction surface of the bearing base. Molybdenum disulfide, graphite, and other materials are embedded to create composite self-lubricating blocks within the metal. With a solid lubricant friction area ranging from 25-65%, these bearings effectively operate at temperatures up to 280°C. While the solid self-lubricating block may have limitations in mechanical strength and load-bearing capacity, embedding it within a metal hole addresses these concerns. This integration results in a dual-function component—a load-bearing metal part and a self-lubricating block.

The lubrication mechanism involves the transfer of molecules from the self-lubricating material to the metal surface during sliding friction between the shaft and the sleeve. This process fills microscopic irregularities, forming a stable solid lubricating film. Consequently, friction between the solid lubricating films prevents adhesive wear between the shaft and the bearing.

The unique amalgamation of copper alloy and non-metal anti-wear materials renders these bearings well-suited for use in environments devoid of oil, characterized by high temperatures, heavy loads, low speeds, resistance to fouling and corrosion, and exposure to strong radiation. Furthermore, these bearings demonstrate exceptional performance in specialized working conditions where traditional lubrication methods are impractical due to immersion in water or other solutions.

The occupied surface area of the self-lubricating block is influenced by operating speed and pressure-bearing strength. For instance, in applications with low operating speed and high pressure-bearing strength, a larger area is allocated to the self-lubricating bearing. The running wheel bearing of a spindle-grabbing trolley, for example, allocates approximately 25% coverage, while the rotating shaft bearing of a spindle-pulling mechanism, requiring full lubrication and having low pressure-bearing strength, allocates about 65% of the area to a white lubricating block.

Mingxu Bearing employs a high-performance copper alloy matrix for its self-lubricating bearings, ensuring high hardness that can undergo heat treatment, with a minimum hardness of HRC45.

Regarding the geometric shape and inlay requirements of self-lubricating blocks, they come in two shapes: cylindrical and rectangular. The shape is determined by the area they occupy, but regardless of shape, firm fixation is crucial to prevent detachment during operation.

Considering the matching clearance value between the bushing and the shaft, the self-lubricating block's linear expansion coefficient is approximately 10 times that of steel. To accommodate temperature changes, the gap between the shaft and the bushing is increased from the original four-level dynamic fit of metal parts (D4/DC4) 0.032~0.15MM to 0.45~0.5MM. The self-lubricating block protrudes 0..2~0.4MM from the bushing metal on one side of the friction pair. This will fully lubricate the bearing during the initial running-in period and reduce the consumption of power drag power.