What is the speed of precision crossed roller bearings and what are the factors affecting the speed?

Rodamientos de rodillos cruzados de precisión are designed for high rigidity, precisión, and load-carrying capacity in a compact space, not for high speed. Their speed capability is generally considered low to moderate compared to other bearing types like deep groove or angular contact ball bearings.

A typical speed for a medium-sized (p.ej., 100-200mm bore) crossed roller bearing under standard grease lubrication might be in the range of 500 a 2,000 Rpm. Sin embargo, this is a very rough estimate, and the actual permissible speed can be significantly higher or lower depending on numerous factors.

The most accurate way to define bearing speed is with a speed factor (dn or ndm value), which combines the bearing size and its rotational speed. For crossed roller bearings, this value is often limited to a range of 100,000 a 300,000, whereas high-speed ball bearings can exceed 1,000,000.

Precision Crossed Roller Bearings Speed

Instead of a simple RPM value, engineers use a speed factor to create a more universal metric that accounts for bearing size.

Speed Factor (dn Value)

n: Rotational Speed (in RPM)

d: Bearing Bore Diameter (in mm)

Sometimes dm (mean diameter) is used, which is (bore + diámetro exterior) / 2.

dn Value = d x n

Why is this used? For a given RPM, a larger bearing has rollers that travel at a much higher surface speed, generating more friction, calor, and centrifugal force. The dn value represents this peripheral velocity and is a better indicator of the bearing’s physical speed limit than RPM alone.

Typical dn Values for Crossed Roller Bearings:

Lubricación en grasa: 70,000 a 150,000

Lubricación de aceite (Oil Bath/Mist): 150,000 a 300,000+

α——El contenido del tamaño de partícula más pequeño que el tamaño del tamiz en la materia prima:

A crossed roller bearing with a 100mm bore (d=100) is lubricated with grease.

Its maximum dn value from the catalog is 130,000.

Maximum allowable speed (n) = dn / d = 130,000 / 100 = 1,300 Rpm.

If the same bearing were lubricated with circulating oil and had a dn limit of 250,000:

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More detailed information about precision crossed roller bearing speed can be found at:https://www.lynicebearings.com/a/blog/precision-crossed-roller-bearing-speed.html