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Method of Reducing Noise of INA Imported Bearing in High Speed Operation
Nov 28, 2018

Most high-speed bearings are angular contact ball bearings, which are mainly used in high-speed rotating occasions with light load. It requires INA imported bearings to have high precision, high speed, low temperature vibration and a certain service life. So how to install high-speed bearings?

1. Bearing installation should be carried out in a clean and dustless room. Bearing should be carefully selected and matched. Bearing diaphragms should be grinded. On the premise of keeping the diaphragms of inner and outer rings as high as possible, the parallelism of diaphragms should be controlled below 1um.

2. The bearing should be cleaned before installation. When cleaning, the inner ring slope is upward, the hand is flexible and there is no sense of stagnation. After drying, a specified amount of grease should be put in. If it belongs to oil mist lubrication, a small amount of oil mist should be put in.

3. Special tools should be used for bearing installation, with uniform force and no knocking.

Main technical indicators:

1. Bearing accuracy index: exceeding GB/307.1-94 P4 accuracy

2. High-speed performance index: dmN value 1.3-1.8x 106/min

3. Service life (average): > 1500 H

Installation kit includes 36 impact rings, 3 sleeves and a rebound-free hammer, all of which are packed in a portable toolbox.

It is often used as supporting parts of high-speed motorized spindle in pairs. It is the key supporting parts of high-speed motorized spindle of internal surface grinder. Unknown how to install high-speed bearings or improper installation, or even brutal installation, in the early failure of bearings accounted for 16%. SKF bearing installation tool TMFT 36 is designed to install INA imported bearings quickly and accurately, while minimizing the risk of bearing damage during installation. The reasonable combination of impact ring and sleeve can effectively transfer the installation force through the interference fit bearing ring, so as to minimize the risk of damage to the bearing raceway and rolling element.

The use of vibration absorption or isolation devices to reduce the noise of bearings or isolate the noise of bearings can achieve good results, but this often costs a lot economically. Sometimes, the mechanism becomes larger, the heat dissipation conditions become worse, or it is easy to rust. When using, it should be considered comprehensively. Only in other measures can it be taken. This method will not be used until the target of low noise is reached. The simplest example is the centripetal ball bearing which bears thrust instead of thrust bearing at high speed. The outer ring of the centripetal ball bearing can be lined with a plastic coat filled with rust-proof lubricant. The thrust bearing with a cover or general thrust bearing can be lined with the same plastic sleeve in its inner hole or outer circle, if permitted, but it can not be phased in rotation control. Friction or interference occurs between adjacent parts. This method has a certain effect of silencing noise. Another example is to add a middle sleeve between the bearing and the seat hole, which can attenuate the vibration force transmitted from the rotating system to the bearing seat, but this requires proper allocation, otherwise the opposite effect may occur.

Another example is the use of a sound absorption and insulation cover to completely seal or as close as possible the bearing system in which noise occurs. The interior of the noise reduction cover is made of glass fiber or polyurethane foam plastics. The steel plate with 0.6-lmm thickness on the inner surface is uniformly distributed with small through holes of 1.2-1.5mm. The total area of the holes is about 25%-30% of the whole interior surface, and the steel plate with 2 mm thickness on the outer surface. Here fiberglass or foam is used to eliminate higher frequency noise, the inner surface with small holes is used to eliminate lower frequency noise, and the thick steel plate on the outer surface is used to isolate the noise from the outside.

The noise of INA imported bearing is not very sensitive to load, but very sensitive to speed. When conditions permit, the same purpose can be achieved by reducing speed and increasing torque, but the noise can be reduced. [Example] In order to reduce the noise of the oil pump system, the noise of the oil pump itself, the oil pump bearings and the oil pump motor bearings has been significantly reduced by replacing the oil pump with a motor with a speed of 1430 r/min and a flow rate of 10 L/min with a speed of 710 r/min and matching with a larger size oil pump to obtain the same flow rate, but the noise of the oil pump itself, the oil pump bearings and the oil pump motor bearings has been significantly reduced. The space occupied by the set of institutions has been expanded, and the cost has also increased.