Slewing bearings, also known as slewing rings, are crucial mechanical components used to support axial, radial, and tilting moment loads in various heavy-duty machines, such as cranes, excavators, wind turbines, and rotating platforms. One of the most critical and common failures in slewing bearings is broken or damaged teeth on the gear ring.

Broken teeth on a slewing bearing can lead to serious operational issues, including abnormal noise, vibration, reduced load capacity, and eventually, total equipment failure. This kind of damage is often a result of improper installation, overloading, poor lubrication, or misalignment during operation.

Causes of Broken Teeth in Slewing Bearings

Overloading:

Static Overload: Applying a load greater than the bearing’s rated static capacity, even momentarily, can fracture teeth.

Dynamic Overload/Shock Loads: Sudden impacts, jerky movements, or unexpected high loads during operation (e.g., a crane hitting an obstruction) can exceed the tooth strength.

Uneven Load Distribution: If the mounting structure is not flat or rigid enough, or if bolts are unevenly torqued, the load can concentrate on a few teeth, leading to overload and fracture.

Poor Lubrication:

Insufficient Lubrication: Lack of lubricant increases friction and heat, leading to accelerated wear (pitting, scuffing) which weakens the teeth and can eventually cause them to break.

Incorrect Lubricant: Using a lubricant with the wrong viscosity, insufficient extreme pressure (EP) additives, or incompatibility with operating conditions can fail to protect the gear teeth.

Contaminated Lubricant: Dirt, debris, water, or metal particles in the lubricant act as abrasives, grinding away tooth material and creating stress risers.

Misalignment:

Improper Installation: If the slewing bearing is not mounted perfectly parallel and concentric with the driving pinion, the load will not be distributed evenly across the face width of the teeth. This leads to edge loading and high stress concentrations, causing tooth breakage.

Structural Deformation: Flexing or deformation of the supporting structures under load can also cause misalignment.

Fatigue Failure:

Repeated cyclic loading, even below the ultimate strength of the material, can lead to the initiation and propagation of cracks, eventually resulting in tooth fracture.

…

More detailed information about the causes and prevention of tooth breakage of slewing bearings can be found by clicking visit: https://www.mcslewingbearings.com/a/news/causes-of-broken-teeth-of-slewing-bearing.html

Repairing a slewing bearing is a complex task that should ideally be performed by experienced professionals or the original manufacturer. However, understanding the general processes involved can be helpful.Repairing slewing bearings involves a careful and methodical process to restore their performance and extend their service life. Here’s a step-by-step guide on how to repair slewing bearings.

Slewing Bearing Repair

1. Initial Inspection and Assessment:

Visual Inspection: The bearing is thoroughly examined for visible damage such as cracks, dents, corrosion, and seal damage.

Performance Check: Turning torque, noise levels, and any signs of stiffness or uneven rotation are assessed.

Clearance Measurement: The internal clearance of the bearing is measured to determine the extent of wear. A dial indicator is often used to measure tilting or rocking of the connected structures.

Lubricant Analysis: If possible, samples of the existing grease are taken and analyzed for the presence of metal particles or other contaminants, which can indicate internal wear.

2. Disassembly and Cleaning:

The slewing bearing is carefully disassembled. This process needs to be done methodically, keeping track of the orientation and position of all components.

All parts (raceways, rolling elements, spacers/cages, seals) are cleaned with appropriate solvents to remove old grease, contaminants, and debris.

3. Non-Destructive Testing (NDT):

The raceways are typically inspected using methods like magnetic particle inspection or visual testing under magnification to detect surface cracks or defects that may not be visible to the naked eye.

Hardness testing may be performed on the raceways to check for any loss of material hardness.

4. Repairability Assessment:

Based on the inspection and NDT results, a qualified engineer determines if the bearing can be repaired. Factors considered include the severity and location of the damage, the overall wear, and the cost-effectiveness of repair versus replacement.

If the damage is extensive (e.g., significant cracking, severe wear on raceways), replacement is usually the recommended course of action.

5. Repair Procedures (Depending on the Damage):

Minor Damage (Cracks, Small Dents): Welding and subsequent machining to restore the original dimensions might be possible. This requires specialized expertise and equipment to ensure proper material properties and dimensional accuracy.

…

For more detailed information on how to repair slewing bearings click to visit: https://www.mcslewingbearings.com/a/news/slewing-bearing-repair.html

Welding column and booms (also known as welding manipulators) are versatile pieces of equipment used to automate and improve the efficiency and quality of welding, especially for long, circumferential, or repetitive welds on large workpieces. They primarily differ based on their mobility, size/capacity, and sometimes the degree of articulation or control.

Welding Column Booms Types

Fixed Type (Stationary):

Description: The base of the column is bolted directly to the workshop floor or a heavy foundation.

Use Case: Ideal for dedicated welding stations where the workpiece is brought to the manipulator. Often used for repetitive tasks on similar-sized components.

Pros: Very stable, takes up a defined footprint.

Cons: Lacks mobility; workpiece positioning is critical.

Movable Type (Free-Standing / Portable):

Description: The column is mounted on a heavy base equipped with casters or wheels, allowing it to be moved around the workshop. It might be moved manually or have a simple motorized drive for positioning.

Use Case: Offers flexibility to move the manipulator to different workpieces or work areas within a bay.

Pros: More versatile than fixed types for varied job locations.

Cons: May require leveling or outriggers for stability during operation, especially for larger models.

Track/Rail Mounted Type (Travel Car Type):

Description: The column and boom assembly is mounted on a motorized carriage that runs on precisely laid rails or tracks on the floor.

Use Case: Essential for welding very long longitudinal seams on items like large pipes, tanks, beams, or ship hulls. The manipulator travels along the length of the workpiece.

Pros: Accurate linear movement over long distances, high productivity for long welds.

Cons: Requires dedicated track installation, less flexible for non-linear work.

Size/Capacity Based Classifications (often overlaps with the above):

Light-Duty:

Shorter boom reach (e.g., up to 2-3 meters).

Lower payload capacity (for lighter welding heads and accessories).

…

For more detailed information on the welding column booms types click to visit: https://www.bota-weld.com/en/a/news/welding-column-booms-types.html

Gantry welding machines are specialized automated welding systems designed for high-precision, large-scale welding applications, particularly in industries such as shipbuilding, structural steel fabrication, and heavy machinery manufacturing. A gantry welding machine operates on a principle of automated movement and precise control of the welding head over a workpiece.

Gantry welding machine working principle and how to achieve 0.1mm welding precision

Gantry Welding Machines Working Principle

Gantry Structure: The machine features an overhead bridge-like structure (the gantry) that spans the welding area. This gantry provides a stable and rigid framework for the welding process.

Multi-Axis Movement: A carriage or trolley carrying the welding head moves along the gantry (typically the X-axis). The gantry itself can also move along rails (the Y-axis), and the welding head often has vertical movement (the Z-axis). This multi-axis movement allows the welding head to reach any point within the machine’s working envelope.

Automated Control System: The movement of the gantry and the welding head is controlled by a sophisticated numerical control (CNC) system or a programmable logic controller (PLC). This system directs servo motors that drive the movement along each axis with high precision.

Welding Process Integration: The gantry system is integrated with various welding power sources and equipment (e.g., Submerged Arc Welding (SAW), Metal Inert Gas (MIG), Metal Active Gas (MAG)). The control system also manages the welding parameters such as voltage, current, wire feed speed, and travel speed.

Seam Tracking (Optional but crucial for precision): Advanced gantry welding machines often incorporate seam tracking systems. These systems use sensors (e.g., mechanical, laser, vision) to detect the actual weld joint in real-time and automatically adjust the welding head position to follow the seam accurately, even if the workpiece has slight variations or distortions.

Material Handling: While not directly part of the welding principle, gantry machines are often integrated with material handling systems (e.g., conveyors, positioners) to move and orient the workpiece efficiently.

Achieving 0.1mm Welding Precision

Achieving such high welding precision (0.1mm) requires a combination of advanced technologies and meticulous engineering:

High-Precision Motion Control System:

High-Resolution Encoders: Servo motors on each axis must be equipped with high-resolution encoders to provide precise feedback on the welding head’s position.

This allows the control system to make minute adjustments to ensure accuracy.

…

More detailed information about the working principle of the gantry welding machine can be clicked to visit: https://www.bota-weld.com/en/a/news/gantry-welding-machine-working-principle.html

Hammer crushers are widely used in mining, cement, metallurgy, and aggregate industries for crushing medium-hard materials such as limestone, coal, and gypsum. However, abnormal vibration during operation is a common issue that can severely impact machine performance and lifespan.Large vibrations in a hammer crusher are a common problem and can lead to premature wear, component failure, reduced efficiency, and safety hazards.

Reasons for Large Vibration of Hammer Crusher

Rotor Imbalance (Most Common Cause):

Uneven Hammer Wear: Hammers wear down at different rates depending on their position and the feed material. If not managed, this creates a significant weight imbalance.

Incorrect Hammer Replacement: Replacing hammers with ones of different weights, or replacing only some hammers without balancing, will cause imbalance.

Hammers should always be replaced in sets (opposite pairs or full sets) and be weight-matched.

Broken or Missing Hammers/Pins: A broken hammer or a lost hammer pin will immediately create a severe imbalance.

Material Buildup: Sticky or wet material can build up unevenly on the rotor, hammers, or inside the rotor discs, adding weight to one side.

Bent Rotor Shaft: A bent shaft will cause the entire rotor assembly to wobble.

Rotor Disc Deformation: If the discs holding the hammers are bent or damaged.

Bearing Issues:

Worn or Damaged Bearings: Worn bearings develop excessive clearance (play), allowing the shaft to move erratically, leading to vibration. Damaged races or rolling elements also cause rough running.

Incorrect Bearing Lubrication: Too little, too much, or the wrong type of lubricant can cause bearings to overheat and fail.

Misaligned Bearing Housings: If the bearing housings are not perfectly aligned, they put undue stress on the bearings and shaft.

Loose Components:

Loose Foundation Bolts: If the crusher is not securely anchored to its foundation, it will vibrate excessively.

Loose Rotor Mounting Bolts: Bolts connecting the rotor to the shaft or bearing assemblies.

Loose Hammer Pins/Bolts: If hammer pins are loose, hammers can shift, contributing to imbalance and impact forces.

Loose Liner Plates or Grate Bars: Can vibrate independently or cause material to jam.

Operational Issues:

Overfeeding: Feeding too much material at once can choke the crusher, leading to uneven loads and vibration.

Feeding Uncrushable Material: Introducing tramp metal or excessively hard material can cause sudden shocks and damage, leading to vibrations.

…

More detailed information about the causes of high vibration of hammer crusher can be clicked to visit: https://www.zymining.com/en/a/news/reasons-for-large-vibration-of-hammer-crusher.html