Y bearings, also known as insert bearings, are a special type of rolling bearing, specifically designed for easy installation and reliable operation.
These bearings are based on sealed deep groove ball bearings, have a convex outer raceway surface and a wider inner ring, which facilitates mounting on the shaft.
Advantages of Y bearings
- Easy installation and replacement: the design of Y bearings allows quick and easy installation, reducing maintenance time and costs.
- Self-alignment: the spherical design of the outer ring of the bearing allows compensation for small angular misalignments between the shaft and the housing, ensuring smooth operation even when the shaft is not fully aligned with the housing.
- Integrated seals: integrated seals protect the bearing from dirt and moisture, increasing bearing life and reducing maintenance requirements.
Applications
Y bearings are widely used in industrial installations where easy mounting and reliability are of paramount importance. Common applications include agricultural machinery, conveyor belts, fans and other industrial machinery where bearings need to be resistant to contamination and varying loads.
Interesting statistics on the causes of bearing failures
According to the SKF industry study and other research, the main causes of rolling bearing failures are:
- 42% – Contamination ingress (e.g. dust, moisture, corrosion)
- 36% – Lack of lubrication or incorrect lubrication
- 12% – Incorrect fitting (e.g. over-tightening, misalignment)
- 10% – Material fatigue, other
The strength of Y bearings is focused on these areas: seals against contamination, factory pre-anchored design, self-adjusting design for easy installation. These features therefore contribute directly to preventing the most common failures.
Practical tips to increase the life of your Y bearing
- Do not overstretch!
When mounting a Y bearing with a caged screw, overtightening can deform the ring. Use a torque wrench – for smaller sizes 3-5 Nm, for larger sizes up to 10 Nm may be the factory specification. Check the manufacturer’s tables. - Clean shaft = longer life
Always clean the shaft before installing a new bearing! A fine layer of rust, dust or old grease will prevent a precise fit, causing radial runout and faster wear. - Choose a seal for the environment
Dusty workshop? Wet plant? Outdoor application? Choose a triple lip or labyrinth sealed Y bearing – it’s more resistant to environmental contaminants and will last longer without lubrication. For agricultural environments, NTN’s AGR seal will be the optimal choice. - Shrinkage recall: 500 hours
For Y bearings, if you have a grease button housing, it is recommended to re-grease every 500 operating hours. Don’t use too much: 1-2 pressures is enough – overfilling can cause damage just as much as underlubrication. - Check the bearing housing too!
Before replacing bearings, check the housing for cracks, over-wear, loose fitting. Even a good bearing will fail in a bad housing. If necessary, replace the complete unit (bearing + housing). - Do not mix brands
Eg: An NTN bearing may not work well in a housing from another manufacturer. Due to mismatch, the seal may not seal properly or the ring may slip. Use a complete NTN unit. - Correctly adjust the bearing in the housing
The outer ring of Y bearings is slightly spherical. After insertion, it is important that it is well seated in the housing. Tighten the retaining bolts evenly – if you tighten them at an angle, the bearing will not “set” and will wear faster. - Pay attention to the material and finish of the shaft
Y bearings will not tolerate an imprecise shaft. The surface must be smooth (Ra < 1.6 µm) and stainless. If the shaft is too soft (e.g. raw steel), it will quickly bite into the retaining screw and slip. - Check the bearing clearance during operation
Noisier operation? Getting hotter? If the inner ring of the Y bearing is loose on the shaft, axial play or slippage may occur. In this case, replace or select a closer-fitting type (e.g. a version with a clamping sleeve). - Use a protective cap in dusty environments
Plastic or metal protective caps are available for Y bearings. These protect the housing opening from solid contaminants – particularly useful for conveyor belts, sawdust, flour or earthy environments. - Size is not the only thing that matters!
There are Y bearings of the same size but different designs – e.g. long inner ring, short inner ring, double-sided mounting versions. Each behaves differently under load, axial movement and impact. Don’t just look at the size – look at the full part number! - Keep a spare bearing handy – but not just any bearing!
Always store the Y bearing lying flat in a dust-free, dry place, preferably in its original packaging. If it sits on the shelf for a long period of time, it’s a good idea to rotate it annually (moving the inner ring by hand) to prevent grease from stagnating.
Y bearings are easy to install, reliable and long-lasting. Their versatility and their various mounting and sealing solutions make them suitable for a wide range of industrial applications, ensuring smooth and efficient operation of equipment.
Search for Y bearings in our webshop or ask our expert colleagues for help in making your choice!
