Causes and diagnosis of braking deviation and delay of crane brake[]

Causes and diagnosis of braking deviation and delay of crane brake12 ton country five crane price how much, 16 tons of truck suspension price, four wheel cross-country crane price, crane manufacturer, which brand of crane is good, 12 tons Fukuda crane, 12 tons Tang Jun crane 998The main deviation of the brake is that the left and right tracks of the left and right wheels or the track chassis of the same axle have different braking effects, so that the vehicle braking is offset to one side. The main reason is generally about the brake shoe and the brake hub and the brake block and the brake wheel gap adjustment is not consistent, or due to individual shoe oil, hardening, exposed rivets and brake drum wear loss round so that the two brake is not consistent. During the test run, it is not difficult to find out the brake failure tires (tracks) when the wheel is braked from the wheel of the vehicle, the direction of the deviation and the traces of the tyre are printed, and the specific reasons can be found out through further examination, so that the trouble can be eliminated.When the brake stops, the brake shoe (brake block or belt) bites the brake hub (wheel), which makes it difficult to start again. This is called braking delay. In this case, the vehicle or the work device is not easy to speed up, and the brake hub (wheel) will be seriously heated. The use of pneumatic brake wheel chassis, if all the wheels are biting, the failure of more than the brake valve failure, such as valve springs broken. The valve closed, the brake release after high pressure air can not be discharged, the brake can not lift.Generally, the hydraulic brake is the brake pedal, the free stroke is too small or the oil return hole is blocked, so that the brake fluid can not be released when the brake pedal is released. When you check, you can open the main pump storage chamber cover, step down the brake pedal, slowly lift, observe the oil return, if not back to the oil, that is too small free stroke or oil back plug. For electromagnetic brake, the relay malfunction should not be ruled out.

Maintenance of main parts of crane brake[]

1. brake hub maintenanceWhen the brake hub is out of roundness of 0.25 mm or has a deep and wide groove on the working face, and when the shaft is larger than 0.1 mm, the brake hub shall be bored. The boring work after the surface roughness should reach Ra less than 1.6um, loss of roundness and different axes is not greater than 0.05mm.After the boring of the brake hub, due to the increase in the size of the internal diameter, will cause the reduction of strength, so it should not exceed 4-6 mm to enlarge the size limit. The friction brake hub of large brake (clutch) of track crane is made of wear-resistant casting alloy, and the maximum allowable repair amount of friction surface is 10%-20% of wall thickness. Generally, the maximum allowable amount of the inner friction surface is less than the outer friction surface, and the allowable amount of repair is small. When the wall thickness approaches the limit size, the surface size of the friction surface is allowed to be repaired by automatic surfacing. For the internal diameter of more than 2mm of the brake hub, with the brake friction should be corresponding thickening.2. repair of brake shoes (belts)When the brake shoe (belt) on the rivet head riveted brake buried in depth is reduced to below 0.5Mm and the surface oil brake too far, burning me***orphic, the friction coefficient is reduced, in order to ensure safe and reliable braking, should be replaced with new or bonded repair by riveting. Brake belts are broken. It is better to replace the brake belt for reliability and safety. If the fracture is not serious, the welding joint can be repaired and polished after welding.

Common faults of main clutch in crane operation[]

Here will mainly describe the mechanical friction type main clutch and the overhead winch system friction clutch fault and maintenance. Engineering machinery used in the main clutch are mechanical friction type, medium and small machinery horsepower mostly monolithic or double clutch, large horsepower powder metallurgy materials engineering machinery commonly used with high friction coefficient, large tablet is the multi disc wet clutch. The friction clutch is divided into two types: regular joint type and non regular type, according to different pressure conditions. The former is used for medium and small horsepower mobile engineering cranes, and the latter is used for larger crawler chassis cranes.1. clutch skid, when the vehicle resistance increases, the speed decreased significantly, while the engine speed has declined little, that is, the clutch slip.The 2. clutch shaking when the clutch according to the normal operation smoothly engage, the vehicle is not gradually and smoothly increase speed, and make the vehicle even intermittent start, jitter, until the clutch is completely combined with the site known as the clutch. The clutch shake causes the driver uncomfortable, and will cause the transmission system parts to accelerate wear because of the impact load.3., clutch separation is not complete, clutch separation is not complete, refers to the clutch lever or pedal in the separation position, the active disk and the driven disk is not completely separated, there is still some power transmission.Clutch separation is not complete, will make the transmission gear difficult, produce tooth impact, damage tooth end; also accelerate the pressure plate and friction plate surface wear, cause clutch heating.4. clutch abnormal sound clutch, abnormal sound occurs in clutch engagement or separation process, and the speed changes. Because the noise is caused by abnormal friction or collision between the parts, it is generally clearer. Such as clutch just when combined, sometimes there will be "sand", "sand" sound, combined with, or separation, or sudden change in speed, there will be "grams", "grams" of the sound, etc..

Common problems of crane hydraulic oil[]

1, why does the temperature of oil rise?The main reasons are insufficient oil or oil pollution. Insufficient oil content is caused by equipment design defects or oil spills. Oil pollution, especially oil oxidation pollutants, can easily cause blockage of cooling system and filter, resulting in an increase in oil temperature2, what is the relationship between oil spills and pollution?When the oil temperature increases due to the above reasons, the viscosity of the oil will decrease, and the low viscosity oil will be easier to seep out of the connecting parts. Keeping low temperatures and cleaning oil is a common way to avoid oil spills.3. How do bubbles come into being?Causes of bubbles: when the filter or plug or air passes through loose fittings, the anti foaming additives in the oil do not work and produce bubbles4. Why does oxidation increase the viscosity of oil?The viscosity of oils used for a long time will not change, except when the oil is particularly oxidized. The general engineer's experience suggests that the viscosity of the oil will decrease when used for a long time, but that is generally judged by the working state of the machine at 50-70 degrees centigrade, while the viscosity test is at 40 degrees centigrade. In fact, as the degree of oxidation increases, the viscosity increases slightly!5, the color of the oil?Long term use of oil increases color because of pigment formation, which is normal. Because pigments dissolve in oil without affecting the quality of the oil, it is incorrect to judge the quality of the oil only by its color.6, what is the deterioration of oil?The accumulation of oxides of oil and the adsorption of particles on the oxide, resulting in a "sand paper" effect, is the adverse consequence of oil deterioration. The deterioration of oil causes wear and tear of the machine. In fact, the deterioration of oil is essentially the oxidation of oil!7. What size of pollutants is harmful to the hydraulic system?Greater than 1um particles on the hydraulic system can cause filter clogging or pump failure. The particles around 1um are close to the thickness of the oil film and are attached to the oil oxidation pollutants to adsorb the pipeline valve parts in the gaps of pipes and valves.8, why measure acid value?The amount of acid value is closely related to the oxidation of oil. It is an important index to check the degree of oxidation of oil. Generally, if the acid value of the oil exceeds the standard, the oil acid value can be reduced by removing the oil oxide.9, the role of water in lubricating oil?Water can cause rust in the circulation system, which can cause valve and system problems and accelerate the oxidation of oil. An oil-water separator can remove water from the lubricant.10, the service life of oilThe oil is affected by air, heat, impurities, and water. However, the oil is completely purified and under 60 degrees of oil changes are very small and can be used for long periods of time. The additives consumed can be replenished by a small amount of new oil.