The four wheels in"four wheels and one belt"refer to the driving wheels,guide wheels,supporting wheels,and supporting wheels of the small excavator.The"one belt"refers to the tracks of the small excavator.The tracks are divided into steel tracks and rubber tracks.They are directly related to the working performance and walking performance of the excavator,and their weight and manufacturing cost account for about one-tenth of the excavator manufacturing cost.
1.Tracks
Classification:There are two types:integral type and combined type.
The integral track has meshing teeth on the track plate,which tend to mesh with the driving wheels,and the track plate itself becomes the rolling track of wheels such as rollers.Generally,most mini excavators use rubber tracks,and some small excavators use steel tracks.The material of track shoes is mostly rolled plates that are light in weight,high in strength,simple in structure and cheap in price.There are several types such as single ribs,double ribs,and three ribs.Today's excavators mostly use three ribs.
Features:Easy to manufacture,but wears out quickly.
2.Driving wheel
The power of a small excavator is transmitted to the track through the traveling motor and drive wheel.It is required that the drive wheel meshes correctly with the track chain of the track,the transmission is smooth,and the track can still mesh well when the track is elongated due to wear of the pin sleeve.The drive wheels are usually located at the rear of the excavator's running gear.
According to the structure,it can be divided into:integral type and split type;according to the pitch,it can be divided into:equal pitch and unequal pitch.
3.Support roller
The function of the track wheels is to transfer the weight of the small excavator to the ground.Because the track wheels will be impacted by the ground when the excavator drives on uneven roads,the load on the track wheels is large,the working conditions are harsh,and they are often exposed to dust.in,and sometimes soaked in muddy water,so good sealing and wear resistance are required.
Features:Most use sliding bearing support.And use floating oil seal to prevent dust.
4.Guide wheel
The guide wheels are used to guide the crawler track to rotate correctly to prevent it from wandering and derailing.Most small excavators also function as rollers.This can increase the contact area of the track to the ground and reduce the ground specific pressure.The wheel surface of the guide wheel is made of smooth surface,with an arm ring in the middle as a guide,and the ring surfaces on both sides support the rail chain.The smaller the distance between the guide wheel and the nearest roller,the better the guiding performance.
5.Tugboat
Its function is to hold the track upward so that the track has a certain degree of tension.
6.Precautions for use in the four-wheel area
The tension of the crawler track is adjusted by adding butter to the oil filling nozzle of the tensioning cylinder or discharging butter from the oil drain nozzle,and adjusts with reference to the standard clearance of each machine model.When the track section pitch is elongated to the point where a set of track sections needs to be removed,the meshing surface of the drive wheel tooth surface and the pin bushing will also be subject to abnormal wear.At this time,appropriate treatment should be carried out before the meshing condition deteriorates,such as replacing the pin with the pin.Turn over the sleeve,replace excessively worn pins and pin sleeves,replace the track section assembly,etc.
The lubrication of the four-wheel area is very important.Many roller bearings are"burned out"and lead to billing because of oil leakage that is not discovered in time.It is generally believed that oil leakage may occur in the following 5 places:due to poor or damaged O-ring between the back-up ring and the shaft,oil leakage from the outside of the back-up ring and the shaft;due to poor contact of the floating seal ring or defective O-ring,oil leakage from the back-up ring There is oil leakage between the outside of the ring and the supporting wheel(supporting wheel,guide wheel,driving wheel);due to the poor O-ring between the supporting wheel(supporting wheel,guide wheel,driving wheel)and the bushing,there is oil leakage from the bushing to the bushing.Oil leaks between the rollers;oil leaks at the oil fill plug due to looseness of the oil filler plug or damage to the seat hole of the tapered plug seal;oil leaks between the baffle cover and the roller due to a bad O-ring.Therefore,you should pay attention to checking the above parts at ordinary times,and add and replace them regularly according to the lubrication cycle of each part.