How to Calculate Limiting Speed of Bearing

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Last Updated on September 16, 2022

If you have questions about a particular bearing or its limitations, you can use the Limiting Speed Calculator. It utilizes engineering data and 20 years of experience to give you an accurate calculation of its Limiting Speed and Service Life. Please note, however, that this calculator is only a guide and other factors may affect its results. If you have special requirements, you should consult with a bearing expert for further guidance.


Stiffness is the ratio of the force and displacement for a bearing. However, it can be difficult to describe the bearing’s stiffness when there are six displacements. Instead, we can consider three loads and three moments on each race, and friction moments on the axis of rotation. This equation can determine the limiting speed of a bearing based on its stiffness. This equation can help design a bearing with the appropriate stiffness.

The basic dynamic load rating of a bearing can be found in the specification table. From this, the service life can be calculated using equation (5-2). The F factor is multiplied by the basic dynamic load rating. This results in a stiffness matrix. A good bearing specification table has the basic dynamic load rating of the bearing, which is a prerequisite for calculating its limiting speed.


how to calculate limiting speed of bearing

The limiting speed of a bearing is the maximum rotational speed that can be achieved without overheating the component parts. The limiting speed of a bearing depends on its stiffness, its dimensions, and how accurate it is. In some cases, the limiting speed may not be the same for two different bearings. This is because the limiting speed is also affected by the type of lubricant, cage type, and the loading conditions.

In the same way, the foundation and bearing housing have different stiffness levels. Similarly, the bearing’s stiffness is less than the stator’s elasticity. Using these stiffness levels, the bearing is stable at a certain speed. Hence, the boundary condition is acceptable up to a certain level. The limiting speed can be influenced by the damping levels of the foundation and bearing housing.

Load capacity

The calculation of the limiting speed of a bearing is based on the information provided about the application and the bearing, along with engineering data and 20 years of experience. But other factors can affect the calculation, affecting the Limiting Speed and Service Life. Hence, the results from the calculation tool should be used for guidance only, and not as gospel. Therefore, it is imperative to perform application-specific tests before using the calculation.

A thermally safe operating speed nth is determined from the heat balance in the bearing. This is the equilibrium of frictional energy and heat dissipation as a function of speed. In addition to this, the permissible operating temperature t is also determined. To calculate the limiting speed, certain conditions must be observed, including correct mounting, normal operating clearance and constant operating conditions. The calculations can be made by solving equations with critical minimum and maximum loads.

In addition to the critical speed, the maximum operating speed should be within a range of 500 fpm. For instance, if the bearing must work at a speed of 4200 rpm in a wheeled vehicle, then it must be designed with a radial and axial component. In a lift, the load is entered using the radial and axial components of the load. Similarly, a sling for a drum requires a non-variable load. The auxiliary calculation is available under the theoretical section of the help.

To calculate the limiting speed of a bearing, first select the design and operating parameters of both the types of bearings. The programme will show you first the recommended design for the bearing and will then carry out an automatic search. It will then display the basic life of both the bearings and then, if necessary, the calculation of the adjusted bearing using the known operational parameters will be performed. It is essential to note that there is no single calculation method that guarantees a bearing will be free of wear and tear.

Contact seals

The limiting speed of a ball bearing using contact seals is a function of its thermal and kinematical permissible speeds. The kinematically permissible speed nzul is a calculation of the kinematically permissible speed. It is calculated by considering the different torque effects in the system. It should be noted, however, that limiting speeds are not always the same.

Non-contact metal shields are a good option for bearings with high internal friction. Metal shields also retain grease and reduce torsional torque against the inner ring land surface. The NICE(r) RS1P seal is a standard seal on 1600, 3000, and 6900 series bearings. This multi-part assembly consists of a nylon seal insert held in place by a metal shield. The DL and Super Ag seals are special high-efficiency contact seals.

The amount of oil required for a satisfactory film is very small. The minimum quantity is a few microinches thick. Any make-up required is limited to reclaiming the losses from atomization, vaporization, and seepage. Therefore, it is important to choose a type of oil that best fits the application. A well-lubricated bearing will last for many years. You can even use a grease-based lubricant if it’s not too high-speed.

Kinematically permissible speed

The maximum operating speed of a bearing is limited by kinematic and mechanical criteria. The speed limit may be increased or decreased based on the tolerance of the bearings, special lubrication methods, bearing materials and designs, and other factors. Characteristical values of the bearing’s speed are based on reference conditions derived from real-world experience. They can be exceeded in certain cases, however.

The kinematically permissible speed of a bearing is defined based on the bearing’s load and the lubricant’s viscosity. The value is calculated using diagrams and takes into account the different torque effects. This speed limits are also based on the temperature of the bearing and its lubricant. The higher the temperature, the lower the kinematically permissible speed of a bearing.

The radial load-free speed curve shows that the high-speed is close to the ORC. It is important to note that the radial load-free speed curve is uniform around the bearing’s circumference. This indicates that the high-speed range is closer to the ORC than the measured speed. Further, the maximum permissible speed is a function of the bearing’s size, lubricant’s temperature, and the design of the cage.

The radial force of a bearing is also important. If the radial force of the bearing is greater than 2,500 N, the orbital velocity of the balls will be smoother. This is because higher radial forces increase the ORC. At a speed of 30,000 rpm, BaBr is high and the cage load is high. The value decreases at a certain radial force.

Load parameter KP

To calculate the limiting speed of a bearing, you must know its geometry. In fluid hydraulic lubrication theory, there are two geometric parameters that must be known: the eccentricity and the length of the bearing. The eccentricity of the bearing must be known, as well as its maximum pressure. The eccentricity must be known for different external vertical loads and rotating speeds. Generally, the eccentricity of a bearing should be smaller than its length and angle of rotation.

The journal bearing has a journal bearing that has a finite length and clearance. Using a twofold secant method, you can quickly compute the equilibrium position and pressure distribution of a bearing. The twofold secant method is more accurate than the dichotomy method, as it requires fewer iterative steps. The twofold secant method calculates the equilibrium position and pressure distribution in a journal bearing. The angle of attitude has a linear relationship with eccentricity, which affects the load-carrying capacity of a bearing.

Once you know the limiting speed of a bearing, the next step is to know how high you can run it. The maximum rotational speed of a bearing depends on its load parameter (Ndm) and the type of lubrication employed. For example, if the Ndm value of the bearing is greater than 100,000 hours, then its limiting speed is 82%.

Besides bearing dimensions, bearing service life is calculated by calculating the axial component force. The basic dynamic load rating of a bearing can be found in the bearing specification table. By multiplying the basic dynamic load rating by the F factor, you can calculate the bearing service life. This formula can also be applied to a limiting speed of a roller bearing. The calculation can be complicated, but it is still very useful.

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