Graphite copper bearings, also known as self-lubricating bearings, are widely used in motor and pump applications in power plants due to their unique properties and advantages. Here’s an overview of these bearings and their use in power plant equipment:Graphite Copper BearingsGraphite copper bearings consist of a high-strength copper alloy matrix with embedded solid lubricant particles, typically graphite. 

Material & Application:

• Test Item: Oil-less (Graphite Embedded Bronze Bush)
• Base Material: Non-ferrous, Copper-based Alloys (e.g., AB-2C, HTB-3, PB-2C, etc.)
• Temperature Range: Suitable for use between -40°C to +250°C
• Applicable For: Can be used in sea-water applications
• Lubricant: Graphite as a non-liquid lubricant, 20-25% share

Composition & Metal Properties:

These bearings offer several advantages:

1. Self-lubrication: The graphite particles provide continuous lubrication, reducing the need for external lubrication.
2. High load capacity: They can withstand heavy loads, making them suitable for demanding power plant applications.
3. Temperature resistance: These bearings perform well in high-temperature environments.
4. Low friction: The graphite lubricant reduces friction between moving parts.
5. Longevity: In low-speed and heavy-duty applications, graphite copper sleeves can last twice as long as ordinary copper sleeves.

Applications in Motors and PumpsIn power plants, graphite copper bearings are commonly used in motors and pumps for several reasons:

1. Motors: These bearings can handle the high loads and temperatures associated with electric motors in power generation equipment.
2. Pumps: Graphite copper bearings are well-suited for pump applications, especially in environments where regular lubrication is difficult or impossible.
3. Turbines: While not specifically graphite copper, bearings play a crucial role in gas, steam, and water turbines, typically using hydrodynamic bearings.

Bushing Halves in Power Plant EquipmentBushings are essential components in power plant machinery, supporting and aligning rotating shafts or axles. In the context of pumps and motors:

1. Shaft guide bearings: In pumps, shaft guide bearing assemblies often contain two fluted cutless rubber bearing bushings separated by lantern ring halves for flushing.
2. Split designs: Some bearings and bushings are designed as split halves for easier installation and maintenance. For example, the Craft Split Roller block allows for rapid replacement, reducing downtime and costs in power generation applications.
3. Material selection: While graphite copper is popular, other materials like rubber are also used for bushings in specific applications, such as propeller pumps in water discharge systems.

Considerations for Power Plant ApplicationsWhen selecting graphite copper bearings and bushings for power plant motors and pumps, consider the following:

1. Load capacity: Ensure the bearings can handle the expected loads in the specific application.
2. Operating conditions: Consider factors such as speed, temperature, and potential exposure to contaminants.
3. Maintenance requirements: Self-lubricating properties can reduce maintenance needs, but regular inspections are still important.
4. Precision: Some applications may require bearings with tight internal clearances and specific precision classes.
5. Replacement ease: Consider designs that allow for quick and easy replacement to minimize downtime.

In conclusion, graphite copper bearings and bushings offer significant advantages for motor and pump applications in power plants due to their self-lubricating properties, high load capacity, and durability. Their use can lead to improved equipment performance and reduced maintenance requirements in the demanding environments of power generation facilities.