Tips and Tricks

Knowledge Of Double Row Tapered Roller Bearings

Tapered Roller Bearings

The specific installation steps and related knowledge of double row tapered roller bearings

Bearings are precision components that are contaminated with bearings and grease and will not operate. In addition, all of the bearings that were already maintenance-free with grease seals, at least 14% of the contamination was only significantly caused by the use of double-row tapered roller bearings in a small percentage of all bearings that failed early. Bearings have excellent manufacturing and design capabilities to provide a variety of harsh working conditions sealing solutions.

The specific installation steps of double row tapered roller bearing:

  1. Before installing the bearing on the shaft, you must first unplug the fixing pin of the fag bearing housing, and at the same time smooth and clean the surface of the journal, and coat the journal with oil to prevent rust and lubricate (allow the bearing to rotate slightly on the shaft).
  2. Apply lubricating oil to the mating surface of the bearing seat and the bearing, and install the double row tapered roller bearing into the bearing seat. Then put the assembled bearing on the shaft together with the bearing seat. Push to the desired location for installation.
  3. Do not tighten the bolts that fix the bearing seat first, so that the bearing shell can rotate in the bearing seat. Also install the bearing and seat on the other end of the same shaft, turn the shaft a few times, and let the fag bearing itself find the correct position automatically. Re-tighten the bearing housing bolts.
  4. Install eccentric sleeves. First put the eccentric sleeve on the eccentric step of the inner sleeve of the bearing, and tighten it by hand along the rotation direction of the shaft. Then insert the small iron rod into or against the countersunk hole on the eccentric sleeve. Hit the small iron rod with a hammer in the direction of rotation of the shaft. Make the eccentric sleeve firmly installed, and finally lock the hexagon socket head screw on the eccentric sleeve

By heating the bearing or bearing seat, the tight fit is transformed into a loose fit by thermal expansion. It is a common and labor-saving installation method. This method is suitable for the installation of fag bearings with large interference.

Before hot-loading, put the bearing or the ferrule of the separable bearing into the oil tank and evenly heat it at 80-100 ℃, then take it out of the oil and install it on the shaft as soon as possible. In order to prevent the inner ring end face and the shaft shoulder from not fitting tightly after cooling, the bearing can be axially tightened after cooling.

When the outer ring of the double row tapered roller bearing is tightly fitted with the bearing seat made of light metal, the method of heating the bearing seat is adopted to prevent the mating surface from being scratched. When heating the bearing with the oil tank, there should be a mesh grid at a certain distance from the bottom of the box, or hang the bearing with a hook.

The bearing should not be placed on the bottom of the box to prevent heavy impurities from entering the bearing or uneven heating. There must be a thermometer in the oil tank. Strictly control the oil temperature not to exceed 100 ℃ to prevent the tempering effect and reduce the hardness of the ferrule.

A. Press fit

When the inner ring of the fag bearing is tightly fitted with the shaft, and the outer ring is loosely fitted with the bearing seat hole, the double row tapered roller bearing can be pressed on the shaft by a press first, and then the shaft together with the bearing is installed into the bearing seat hole Inside. When press-fitting, on the end face of the bearing inner ring, pad a soft metal material assembly sleeve “copper or mild steel”.

The inner diameter of the assembly sleeve should be slightly larger than the journal diameter, and the outer diameter should be slightly smaller than the bearing inner ring rib to avoid pressing on the cage.

Double row tapered roller bearings have a tight fit between the outer ring and the bearing seat hole. When the inner ring and the shaft are loosely fitted, the bearing can be pressed into the bearing seat hole first. At this time, the outer diameter of the assembly sleeve should be slightly smaller than the seat hole. diameter.

If the bearing ring is tightly fitted with the shaft and the seat hole, the inner ring and the outer ring should be pressed into the shaft and the seat hole at the same time during installation, and the structure of the assembly sleeve should be able to press the end faces of the inner ring and the outer ring of the bearing at the same time.

B. Heating with

By heating the fag bearing or bearing seat, the thermal expansion is used to convert the tight fit into a loose fit installation method. It is a common and labor-saving installation method. This method is suitable for the installation of bearings with large interference.

Before hot-loading, put the double row tapered roller bearing or separable bearing ring into the oil tank to heat evenly at 80~100℃, then take it out of the oil and install it on the shaft as soon as possible. In order to prevent the end face of the inner ring and the shaft shoulder from cooling, The fit is not tight, and the bearing can be axially tightened after cooling.

When the outer ring of the bearing is tightly fitted with the light metal bearing, the hot-fitting method of heating the bearing seat can be used to avoid the mating surface from being scratched.

Or hang the fag bearing with a hook. The double row tapered roller bearing cannot be placed on the bottom of the box to prevent precipitated impurities from entering the bearing or uneven heating. There must be a thermometer in the oil tank, and the oil temperature must not exceed 100 ℃ to prevent The back effect occurs, which reduces the hardness of the ferrule.

Tapered Roller: Common Knowledge about Continuous Casting Bearings

Continuous casting bearings are a type of steel bearings. Continuous casting bearings are often used in iron and steel machinery, and it is a commonly used bearing. It belongs to an imported brand and is an imported tapered roller bearing that can be self-aligning developed by Japan Seiko. This bearing is mainly used in the Guide Roll of steel continuous casting equipment.

The finite element method is used for strength planning, and the development is completed with continuous casting simulation equipment. The durability life is 3 to 4 times that of the general self-aligning tapered roller imported bearing (used at the fixed end of the guide roller).

Continuous casting bearings reduce maintenance costs. Because the steel continuous casting equipment is difficult to form oil film, heavy negative, low speed, high temperature, high humidity, and debris is generated during casting, the working environment is extremely harsh. In this state, due to the heavy load of the continuous casting bearing, it is easy to cause severe bending and deformation of the guide roller.

In order to deal with the above problems, it is necessary to set a spherical race on the outside of the external gear as an aligning device so that it does not bend. Therefore, more imported brands such as SKF, TIMKEN and NSK have correspondingly developed bearings with higher configuration and higher precision.

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