The bucket wheel sand washer is a high-efficiency sand washing equipment used with the sand making machine. It can remove impurities covering the surface of sand and gravel. At the same time, destroy the water vapor layer covering the sand to play a role in cleaning. It is more common in mine washing operations. The motor drives the impeller to continue to rotate after being decelerated by the V-belt, reducer, and gears. Due to its huge daily workload and often high-load operation, some failures can occur during work, such as gear damage, stator, rotor core malfunction, etc.
Fault Analysis and Treatment of Wheel Bucket Sand Washing Machine
Gear Damage
The gear is one of the main parts of the wheel bucket sand washing machine, and there are three types of wear:
- Adhesive wear
Caused by metal-to-metal contact, where surfaces bond together and then tear apart, possibly due to insufficient lubricant or gears not meshing properly. - Abrasive wear
Caused by foreign particles such as dust and sand. - Corrosive wear
The chemical attack on gear surfaces by contaminated lubricating oil or additives.
If the gear is damaged, it will seriously affect the working condition of the sand washing machine and the working efficiency of the entire production line.
The following four reasons generally cause gear damage
1. The material selection of the gear needs to meet the requirements. The strength of the gear itself needs to be more, and the load it receives is too large, which leads to its damage.
2. The precision of gear machining and the hardness of the tooth root after heat treatment did not meet the requirements.
3. During the long-term operation of the sand washing machine, the gears lack oil and are not lubricated in time, and dry wear with the machine’s internal parts damages the gears of the sand washing machine.
4. The maintenance of the wheel bucket sand washing machine shaft and the reducer’s low-speed shaft has yet to reach the balance specified in the instruction manual, resulting in damage to the machine’s gears. In severe cases, it may also cause damage to the bearings.
Stator and Rotor Core Failure
The stator and rotor are made of silicon steel sheets insulated from each other and are the magnetic circuit part of the motor. Once the iron core fails, the eddy current will increase, and the iron core will be partially overheated, which will affect the regular operation of the motor.
The following aspects mainly cause stator and rotor core failures
1. Excessive wear or poor assembly of bearings will cause the stator and rotor to rub against each other, resulting in damage to the surface of the iron core, which in turn will generate a short circuit between the silicon steel sheets, increase the iron loss of the motor, and cause the temperature rise of the motor to be too high.
Solution: Use a fine file and other tools to remove the stabs, eliminate the short-circuit of the silicon steel sheet, clean it, apply insulating paint, and heat and dry.
2. Excessive force is used when removing the old winding, making the teeth crooked and open outwards and damaging the iron core.
Solution: When the alveolar is crooked, it can trim with tools such as needle-nose pliers and wooden hammers to reset the tooth cavity, and add hard insulating materials such as green shell paper and bakelite board between the silicon steel sheets that are not easy to reset; And when the tooth end of the iron core opens axially outward, and the pressure rings on both sides are not tight, open a hole in the center of the disc (the outer diameter of which is slightly smaller than the inner diameter of the end of the stator winding) made of two steel plates, and a Tighten the stud bolts, clamp both ends of the iron core, and then tighten the stud bolts to restore the iron core to its original shape.
3. Corrosion of the surface of the iron core due to dampness and other reasons.
Solution: At this time, polish it with sandpaper and then coat it with insulating paint.
4. The grounding around the group generates high heat and burns the iron core or teeth.
Solution: If the iron core groove or teeth are burnt, use tools such as chisels or scrapers to remove the deposits, apply insulating paint and dry them, and if it affects the firmness of the winding, you can use epoxy resin to repair the burnt parts of the iron core.
5. The connection between the iron core and the frame is loose.
Solution: Tight the original positioning screw. If the positioning screw fails, re-drill the positioning hole, tap on the machine base and tighten the positioning screw.
6. Due to the short circuit or grounding of the stator winding, the arc burns the iron core and damages the insulation between the silicon steel sheets, resulting in a short circuit.
Solution:
- When the burn is not serious, clean the iron core first to remove dust and oil, and file the burnt and melted local silicon steel sheet off with a small file, polish and smooth, and eliminate the defect of sheet-to-sheet fusion.
- Take out the ventilation slot of the stator core near the fault point so that the silicon steel sheet has a certain room for loosening during repair, and then use the steel sheet to peel off the silicon steel sheet at the fault point and remove the carbides on the burned silicon steel sheet.
- Coat it with silicon steel sheet insulating varnish.
7. The iron core is loose due to poor fastening and motor vibration.
Solution: Insert a thin layer of mica, and finally, drive the ventilation slots in to keep the iron core tight.
8. Accidentally damaged by mechanical force during overhaul.
Solution: Pay attention to protection during maintenance.
Because of the above reasons, we should select the sand washing machine made by a large factory. Regardless of the quality of the fuselage body or the accessories, it will be guaranteed. For maintenance work, refuel the sand washer regularly, and check whether the bearing is damaged and the degree of wear of the sealing ring in time. If there is wear, check the lubricating oil of the parts immediately to ensure that the oil is on the volume line and clean and pollution-free. Furthermore, when installing the sand washing machine, pay attention to the installation standard and distance, and the shaft of the sand washing machine and the low-speed shaft of the reducer should be adjusted to better parallelism to ensure the stability of the equipment and prolong the service life of the sand washing machine.