Expert in precision bearings for machine tools

What is a high-speed bearing? Does it belong to high-speed bearings that rotate quickly? This is probably the idea of most people, and it can be imagined that this is wrong. Therefore, today we will talk about the relevant introduction of high-speed shafts and what is the difference from ordinary bearings.

1、 Introduction to high-speed bearings

The high, medium, and low speeds of bearings are not determined by rotational speed, but by linear speed. Generally, high-speed bearings refer to bearings with speeds exceeding 60m/s. Some small bearings can easily reach tens of thousands of revolutions per minute, but they are not high-speed bearings. Generally, high-speed bearings are sliding bearings, such as liquid static pressure bearings, liquid dynamic pressure bearings, gas static pressure bearings, and gas dynamic pressure bearings, which are all suitable for high-speed rotation. However, general rolling bearings are suitable for low to medium speed rotation, and special requirements are required for high-speed rotation using rolling bearings.

Moreover, high-speed grease is a better choice for lubrication of high-speed bearings, as it generates heat due to friction during high-speed operation. If the temperature is too high, ordinary grease will evaporate and dry, losing its lubrication effect and causing damage to the bearings.

2、 The difference between high-speed bearings and ordinary bearings

1. Different functions

(1) High speed bearings

In order to ensure that the deformation of the raceway of the bearing after installation is small, the interference fit of the angular contact ball bearing cannot be too large, and the centrifugal force at high speed and thermal expansion at high temperature can either offset the normal pressure on the mating surface or cause the mating surface to relax.

(2) Ordinary bearings

Ordinary bearings are an important component in contemporary mechanical equipment, whose main function is to support the rotating body of the machinery, reduce the friction coefficient during its movement, and ensure its rotational accuracy.

2. Different characteristics

(1) High speed bearings

Rolling bearings with a Dmn value exceeding 1.0x106mm.r/min, where Dm is the average diameter of the rolling bearing and n is the speed of the inner ring. In practical applications, the Dmn value of high-speed imported bearings has reached 3.0x106mm.r/min.

(2) Ordinary bearings

Hardness is one of the important standards for bearing quality, which has an indirect impact on contact fatigue strength, wear resistance, and elastic limit. The hardness of bearing steel under operating conditions should reach HRC61~65, which enables the bearing to achieve high contact fatigue strength and wear resistance.