2025-09-01 06:37:09PRS Bearings
Crossed roller bearings are precision components widely used in industrial machinery, robotics, machine tools, and rotating equipment where high rigidity and accuracy are required. Due to their unique design, consisting of cylindrical rollers arranged orthogonally between inner and outer rings, these bearings can simultaneously support radial, axial, and moment loads with exceptional stability.
However, unlike standard rolling bearings, cross roller bearings demand careful handling during disassembly. Incorrect procedures may lead to deformation,contamination,roller misalignment, or even irreversible damage to raceways and rolling elements.Therefore, understanding the correct disassembly method is essential not only for ensuring smooth maintenance but also for extending the service life of the bearing and the equipment it supports.
Before you start, make sure you have a clean workspace and the necessary tools. The correct approach is to use specialized bearing pullers and presses to apply force evenly. Never use a hammer or chisel directly on the bearing, as this can cause irreversible damage.
Mechanical Pullers: These are the most common tools, with two or three jaws that grip the bearing's inner or outer ring. They apply even pressure to pull the bearing off the shaft or out of the housing.
Hydraulic Pullers and Presses: For larger bearings or those with a very tight fit, a hydraulic tool provides greater, more controlled force.
Heating and Cooling: If the bearing has a tight interference fit, using a bearing induction heater to expand the inner ring or cooling the shaft with liquid nitrogen can make removal much easier. Heating the bearing to about 100°C (212°F) is a common method.
Specialized Tools: Some cross roller bearings, particularly smaller ones, may require specific tools designed by the manufacturer for disassembly.
Preparation:
Safety First: Disconnect any power to the machinery and use a lock-out/tag-out procedure to prevent accidental startups. Wear personal protective equipment (PPE), including safety glasses and gloves.
Cleanliness: Thoroughly clean the area around the bearing to prevent dirt or debris from contaminating the bearing or the machinery.
Assess the Bearing: Determine if the bearing is mounted with a tight fit, a slip fit, or secured with fasteners. Check for any locking nuts, snap rings, or other components that need to be removed first.
Removal:
Apply Force Evenly: Place the jaws of the bearing puller on the ring that is being removed (the inner ring if it's on a shaft, or the outer ring if it's in a housing). The force should never be applied through the rolling elements (rollers).
Use Heat if Needed: If the bearing is stuck, apply heat to the ring using a specialized heater. The expansion from the heat will help loosen the fit.
Gentle Tapping (with caution): In some cases, a gentle tap with a plastic or rubber mallet might help loosen a bearing, but this should be a last resort and should be done with extreme care to avoid damage.
Post-Disassembly:
Inspection: Once the bearing is removed, inspect it for any signs of wear, cracks, or damage to the raceways or rollers. This helps determine if the bearing needs to be replaced or if it can be reused.
Clean and Lubricate: If the bearing is to be reinstalled, clean it thoroughly with a suitable solvent, dry it completely, and apply new, appropriate lubricant before reassembly.
Storage: Store the bearing in a clean, dry place to prevent corrosion and contamination.
Because of their precision structure, improper handling during disassembly can lead to damage, reduced accuracy, or premature wear. Correct disassembly is essential not only to ensure the longevity and performance of the bearing itself but also to maintain the reliability of the machinery in which it is installed. By following a careful step-by-step process and using appropriate tools, technicians can safely remove cross roller bearings without compromising their functionality or structural integrity.
