EN
The water pump bearings are subjected to extreme demands: round-the-clock rotation, exposure to coolant, temperature changes and moisture. Leakage of grease and ingress of contaminants are the two most common failure causes. Awareness of the causes of these problems can help in their prevention to help prolong bearing service life and minimize maintenance expenses. We know that material quality and design are key factors for long-term reliability in high quality bearing steel tubes, deep groove ball bearings and bearing sleeves manufacturing.
1. Choose the Right Sealing Design
The first protection against leakage and contamination is the seal. A seal of this type will prevent grease from leaking out and will keep water and dirt out of the bearing cavity.
In the case of water pump applications, especially double-lip seal structures are effective. The first lip is inside the bearing space to trap grease and the second lip is pointing outwards to prevent the entry of moisture and particles. This is a two-layer solution and thus solves both halves of the problem at once.
A double lip seal, however, can fail to serve as a seal in extreme application if dirt and debris get between the inside lip and its surface. Advanced sealing solutions involve adding extra protective features, such as clamping ring seals and/or compound sealing with water-throwing rings, to minimize direct contact of contaminants with the seal lip, thus minimizing wear rates.
For water pump uses, you might want to choose bearings that have built-in sealing mechanisms – these include the sealing unit within the bearing itself. This integration will reduce tolerance "stack up" and assure accurate surface to surface sealing, essential for good sealing throughout the bearing's life.
2. Select Corrosion-Resistant Materials
Moisture ingress is very damaging as it causes corrosion of rolling elements and raceways. Bearing steel is not a corrosion-proof material, the chromium content of GCr15 bearing steel is only about 1.5%, which is much lower than the chromium content of about 13% that is necessary for a material to have reasonable corrosion resistance. The main function of the chromium in bearing steel is to improve mechanical properties and not corrosion resistance.
The corrosion process starts immediately moisture enters the seal, causing damage to the surface quality, friction, heat and subsequently progressive deterioration of bearings and seals. It is because of this that sealing integrity is so important.
If high moisture exposure conditions are required, stainless steel bearing applications are available. Stainless bearings are harder than normal bearing steel, but have a lower hardness; they also are more expensive, but are preferred for use in corrosive environments. Instead, concentrate on design solutions which will keep moisture away from the bearing by using better sealing and housing solutions.
Our high-carbon chromium bearing steel grades such as: GCr15, SAE52100, 100Cr6, SUJ2 and EN31 are used to produce our deep groove ball bearings and bearing sleeves, which have outstanding wear resistance and fatigue strength. With an appropriate heat treatment, the raceway hardness is normally in the range of 60-64 HRC, thereby increasing the durability against wear and surface damage.
3. Use High-Quality, Waterproof Lubricants
The type of lubricant used will affect both leakage and the life of the bearings. Wear and leakage will occur more rapidly with the use of incompatible grease. These waterproof greases work well in moist conditions, and do not need to be applied in large quantities.
The type of lubricant to be used should consider the speed rating of the bearings and the operating temperature range. Synthetic oils have excellent temperature resistance and can be manufactured to give the best sealing and lubricating properties. For more sophisticated sealing, porous lubricant reservoirs can be filled with water-insoluble lubricants, providing lubrication continuously during the bearing's working life, even if the coolant enters the bearing.
Lubrication maintenance is also important. Apply small amounts of grease at regular intervals, not forcing it into the bearing at long intervals which may result in pressure being built up and damage to the seal. This method is used to ensure adequate lubrication without detriment to seal conditions.
4. Ensure Precision Manufacturing and Proper Installation
The poor manufacturing tolerances and improper installation cannot be overcome by the best possible sealing design and materials. The accuracy of the raceways, the quality of the sealing surface and the integrity of the fit of parts are directly related to bearing life.
Precision manufacturing ensures:
Smooth motion of the rolling elements in the raceways.
The proper interference fits seals in to keep them in place.
Precise surface finishes to minimise friction/wear.
Appropriate material hardness for wear resistance.The installation practices are also important. Seals can be damaged during installation if improper handling, alignment or force is used, resulting in stress concentration areas that cause seal failure. Raceway brinelling can result due to improper handling, misalignment or excessive force during installation, which can create stress concentration areas that cause raceway failure. Never deviate from recommended installation procedures, use proper tools and examine parts prior to assembly for damage.
The lifespan of water pump bearings is influenced by the overall strategy of using an effective seal that resists corrosion, using quality lubrication, and precision manufacturing. Using bearings that have excellent sealing systems, selecting the right materials and lubricants for the operating environment, and installing them correctly can help keep bearings from leaking and help extend their service life.
CIXI HOTO METALLIC PRODUCT CO., LTD is a professional manufacturer, which has established ISO9001, ISO14001, OHSAS18001 management system, and will provide water pump-related bearing steel tubes, bearing sleeves and deep groove ball bearings to meet the needs of water pump applications. Located in the China High-tech Industrial Area, backed by convenient access to Shanghai and Ningbo ports, we can make timely delivery to our customers around the world.