Procedure of bearing products handling at the customers warehouses and lines
Certain skills and accuracy are required for failure-free bearings operation during its handling. Bearings are precision parts that require care in their acceptance, installation, and other manipulations.
The information presented in this chapter is general in nature and is intended to identify the basic requirements for procedure of bearing products handling.
BEARINGS STORAGE AT WAREHOUSES
Bearings manufactured under the brand name BBC and packed n corrugated boxes are delivered to the customers’ warehouses, where they are removed from the trays (pallets) and put into the transport crates, and then placed on the racks in not more than three layers. Premises for bearings storage should be enclosed, heated, dry, equipped with ventilation and protected from penetration of aggressive gasses. Ambient air temperature and relative humidity at the bearing products warehouses should be 20 ± 5 ºC and ≤ 60 %, respectively. It is not allowed to remove dust from corrugated boxes and rackswith a wet cloth.
In case of recent packing damage, immediate usage of bearings for production (assembling into a unit) is allowed.
Bearings shelf life at warehouses shall not exceed the shelf life specified in the accompanying document, from the date of manufacture including the period of storage at the manufacturer, the period of delivery, transportation, etc.
DEPRESERVATION OF BEARINGS
Bearings lubricated with liquid preservation oil can be mounted in production units without depreservation, provided that similar lubricants are used in the unit. However, if it is assumed that the bearing will operate at very low or very high temperatures, it should be washed and dried thoroughly. For bearings flushing it is recommended to use lacquer petroleum or kerosene.
Capped bearings prefilled with lubricantion, should not be washed before using.
In case of necessity, this type of bearings shall be wiped with a dry or wetted in lacquer petroleum and squeezed cotton cloth. Only mounting interface rings and outside surface of a shield and casings shall be wiped.
In case the capped bearings are delivered without excess lubricants on the surfaces preventing their installation, they shall not be wiped.
PROCEDURE OF BEARINGS HANDLING BEFORE INSPECTION/INSTALLATION
While handling the bearings, both in and without packing, it is necessary to be careful to avoid bumps and jerks. It is prohibited to rotate bearings without an oil film on running surfaces.
During procedure of bearings handling supplied in corrugated boxes or other crates, it is necessary to observe the following sequence:
- take the crate with bearings to the place of inspection/installation;
- open the corrugated box cover (correct – pic. 3.1, incorrect – pic. 3.2), take out the accompanying documents, unwrap the protecting cover of polymer film, remove the seals;
pic. 3.1 pic. 3.2
- take one roll or board with bearings out of the corrugated box;
- carefully unfold the roll with bearings on the table, avoiding paper rupture, or take out of the board, avoiding the bearings scattering;
- operations shall be done with hands in rubber or other gloves leaving no contamination, hairs, threads
(correct – pic. 3.3, incorrect – pic. 3.4);
pic. 3.3 pic.3.4
- take the required number of bearings out of the roll or board, wrap the unused bearings back into the same packing material. Prior to inspection, all bearings taken for preservation grease removal are wiped with a dry cloth of napless material or, if necessary, rinsed with clean diesel fuel.
Before the installation,ensure that bearing face has no wastes and check the accuracy of the sizes of all components.
Measuring tools and mounting surfaces must have the same temperature as bearings, It is especially important dealing with big bearings.
After completion of the shift task, the bearings not used for assembling shall be preserved: enclosed bearings shall be wrapped into inhibited and paraffin paper, open-type bearings shall be emerged into industrial oil, with the excess oil bled down, also wrapped into paraffin paper and packed into corrugated boxes.
During displacement of containers with corrugated boxes by technological transport exlude its’ failing.
In case of corrugated boxes failure products must be isolated. Comsumer’s technological containers must ensure bearing safety and absence of damages and wastes prior filling them to the assembly.
During the bearings handling, it is not allowed:
- to stack the bearings unwrapped or in bulk (correct – pic. 3.5, incorrect – pic. 3.6).
pic. 3.5 pic.3.6
- to stack and store unpacked bearings for more than two hours;
- rough handling of bearings – dropping, falling, etc.
In case of falling, bearing is a subject ti disposal.
- getting of wastes, foreign matter, etc. inside the bearing.
In case of foreign matter getting inside the bearing, the bearing shall be rinsed with clean diesel fuel.
Failure to observe the rules above shall result in mechanical damage of bearings, occurrence of corrosion, scratches, nicks and other defects.
Bearings with identified defects caused by improper handling are subjects to disposal.
BEARINGS HANDLING DURING INSTALLATION
During bearings preparation for installation, the identification marking on packing and on the bearings themselves is checked for compliance with the technical documentation requirements.
Before the bearings installation, the bearing-mating surfaces of shafts and casings shall be thoroughly flushed, wiped, dried and covered with a thin layer of grease.
Lubrication channels shall be purged and cleaned from chips, and other metallic and non-metallic particles.
The shafts shall be checked for straightness (absence of bending), the casings shall be checked for misalignment as per the standards set forth in the technical documentation for the unit.
Open-type bearings shall undergo visual examination for presence of a complete set of rolling elements, absence of signs of contamination, corrosion, retainer damage.
Enclosed bearings shall be checked for availability of seals and absence of damage.
Bearing-mating installation surfaces of casings (bores and end faces) and shafts (mounting surfaces and ends) shall have no nicks, scratches, deep notches as a result of poor grinding, corrosion, burrs. During bearings installation into units, it is strictly prohibited to immediately hit the bearings and their parts.
Assembling and dismantling of bearings shall be performed using presses and special tools providing for smooth (nonimpact) rings assembling. During the bearings assembly, it is allowed to use only attested installation tools. The tools used for operations with bearings should be clean and free from burrs.
It is strictly prohibited to transfer the installation force via the rolling elements, retainer and bearing protection elements. The method of assembling safe for the bearing should be indicated in the technical documentation for units assembling. During the bearings installation onto the shaft, the pressing force shall be transferred via the inner ring (pic. 3.7 - correct, pic.3.8 - incorrect).During the bearings installation into the casing, the pressing force shall be transferred through the outer ring (pic. 3.9 - correct, pic.3.10 - incorrect).
pic 3.7pic. 3.8
Manufacturer will not accept claims for bearings damaged in consequence of mishandling.