In this article, we will focus on the mounting of bearings and learn about the different methods of mounting bearings
Mounting is the installation of a ball bearing into a shaft and housing.
Did you know? About 16% of all premature bearing failures are caused by a damaged fit. This is usually because maintenance technicians are not trained in the correct method or are unable to use the correct tools. Mounting methods can significantly affect bearing performance. Therefore, the process needs to be applied carefully to ensure they perform to their maximum potential.
1. Cold mounting
Machine's
Drive method
Oil injection method
2. Thermal inlay
Induction heater
Heating cabinets and electric heating plates
Before we delve into the bearing mounting process, it is important to understand a few basic terms.
interference fit: a fit in which the minimum diameter of the shaft should always be larger than the maximum size of the hole.
Bearing internal clearance: (radial and axial internal clearance) the distance that one bearing collar can move relative to another.
We recommend that you do some preparatory work before you start the mounting process. Here are the 2 steps you need to perform to make your job easier.
1. Before installation
Check the size and shape accuracy of the relevant components
Record the values in the report
2. Prepare the relevant components
Assemble all components needed for the installation
For a tight fit, apply a thin layer of light oil to the seat
For a loose fit, apply an anti-micro-movement agent to the bearing seats
Now that we have covered the groundwork, let's delve into two mounting methods: 1.
1. Cold mounting
Cold mounting is a method of mounting bearings without heat. This technique uses both mechanical and hydraulic methods.
As mentioned above, there are 3 types of cold mounting methods, each used for a different application.
I. Mechanical method
First, here are some basic tools for mechanically mounting bearings.
wrench
Socket
Assembly tool (TMFT)
Dead Hammer
This is a useful technique when driving small bearings with cylindrical bores onto shafts or into housings.
ii. Drive method
The thrust method is a hydraulic technique. Some of the important tools used in this technique are
Lock nut wrench
Hook wrenches
Hydraulic nuts and pumps
The hydraulic method is much more powerful compared to the mechanical method. If used improperly, hydraulic tools may remove radial clearance from bearings.
Applications
This is the preferred technique for driving medium to large bearings with tapered bores onto tapered seats. The method uses hydraulic tools.
III. Oil Injection Method
This oil forms a film between the two surfaces, thus reducing friction and making mounting easier. Note, however, that for this procedure, both the pipe and the recess should already be in place as part of the shaft design. If not, the grooves, feed channels and threaded connections must be machined into the shaft or sleeve before performing the oil filling.
Applications
This method also uses hydraulic tools to facilitate the mounting of medium and large size bearings with a tapered bore by a film of oil injected between the inner ring bore and its seat.
2. Thermal mounting
Hot mounting uses heat to expand the bearing, reducing the interference fit and allowing the bearing to slide easily onto its mating parts.
Let us look at the different methods of using heat to mount bearings.
Ise. Induction heater
Induction heaters are the most effective way to heat bearings for thermal mounting. The induction method requires the preparation of several tools.
Induction heater (of course!)
Heat-resistant gloves
Yoke
1. An electric current flows in the heater's coils, creating a magnetic field in the core.
2. This creates eddy currents in the bearings.
3. The bearing heats up due to the resistance of the bearing material to the eddy currents.
4. To eliminate the typical interference fit, the temperature difference between the bearing and the ambient temperature is approximately 90°C.
ii. Electric heating plates and heating cabinets
These devices are fairly easy to use. Before using the equipment to heat the bearing, set the preset temperature accordingly.
While ovens and hot plates can be used for batch heating of small bearings, they are usually inefficient and time consuming for heating larger bearings.
The precise tools and procedures required to mount bearings vary by type, size, speed, application, and industry. Our team of experienced engineers are on hand to provide expert consultation and advice to help you install them properly to extend the efficient operation of your equipment.
