Which is better, roller bearings or journal bearings for tricone roller rock drilling bits ?

We may not be able to know  the bearings of the drill bit from the surface of the drill bit, but the quality of the bearings is very important. Bearings are divided into ROLLER BEARING and JOURNAL BEARING.

The use of journal bearings and roller bearings in roller drill bits each has its own advantages and disadvantages, and the specific choice depends on the usage scenario and needs.‌

Advantages and disadvantages of journal bearings

‌Advantages

‌ 1)Strong carrying capacity -Journal bearings have a large pressure-bearing area and can withstand large loads, making them particularly suitable for heavy-load and low-speed working environments.

2)‌Highly adaptable- Under extreme working conditions, such as high temperature, high pressure or environments containing solid particles, sliding bearings show better adaptability。

‌ Disadvantages

1)High friction coefficient-The friction coefficient of the sliding bearing is large, the resistance is large during startup, and the friction coefficient is greatly affected by external factors.

2)Severe wear and tear-Under high speed or high load conditions, journal bearings are prone to wear and have a relatively short lifespan.

Advantages and disadvantages of roller bearings

Advantages
1)Low friction coefficient-The friction coefficient of rolling bearings is small and stable, suitable for high-speed and low-friction environments.
2)long drill bit life-Due to low friction, rolling bearings generally have a longer life and lower maintenance costs.
Disadvantage
1)Limited carrying capacity-Roller bearings have relatively low load carrying capacity and perform poorly especially under high loads and shock loads.
2)Limited scope of application-Roller bearings tend to generate noise at high speeds and are not suitable for heavy loads and high speed working environments.
Application scenario comparison
Since roller bits usually work under heavy load and low speed, sliding bearings are more suitable for this application scenario due to their strong load-bearing capacity and adaptability. In addition, sliding bearings in roller

The tricone rock drilling bits are often used to withstand large impact loads and solid particle environments, which further highlights their advantages.