The crane slewing bearing is an important “joint” of the crane, so its maintenance is very important. So how to maintain the crane slewing bearing?

When carrying out maintenance work, pay attention to the danger of being dragged into the rotary pinion, crushing and shearing. When performing the following tasks, the relevant personnel shall ensure that when starting the engine to perform the necessary slewing and luffing operations, any maintenance personnel are not in the danger zone between the main boom, the loading vehicle and the roller, or between the vehicle and the roller. Danger zone between crane operators (in the driver’s cab).

Check the bolts of the slewing bearing

1. Visually inspect the bolts on the slewing bearing before each crane operation or at least once a week;

2. After the slewing bearing has worked for 100 working hours, check whether the bolts are loose, and check again after 300 working hours; after that, check every 500 working hours; in severe working conditions, shorten the inspection interval. If the bolts are found to be loose during the inspection, please stop the construction operation, and immediately contact the local after-sales service department, and the factory or industrial technicians will check and decide whether to disassemble and inspect immediately;

3. The slewing bearing should be filled with lithium-based grease before installation;

4. When replacing the bolts, wipe the bolts clean, apply thread tightening glue, and then tighten them; use the crane according to the requirements of the operation manual and the lifting performance table, or check the tightening bolts regularly as required, so as to avoid the fatigue damage of the bolts.

Routine inspection of slewing bearings

1. Regularly check the flexibility of the rotation; if noise or impact is found, it should be stopped immediately for inspection, troubleshooting, and dismantling and inspection if necessary;

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Details can be accessed by clicking here:https://www.excavatorbearing.com/a/bearing-knowledge/truck-crane-slewing-bearing-maintenance.html

In the operating cost of concrete enterprises, the proportion of fuel consumption of concrete mixer trucks is as high as 53%. How to reduce fuel consumption has become an urgent problem for enterprise managers to improve. In this regard, the tank car sales manufacturers have made a detailed introduction to the important factors affecting fuel consumption, hoping to help you better.

Factors affecting the fuel consumption of concrete mixer trucks:

The fuel economy factor of the mixer truck 1: The use of the mixer truck 

The main factors affecting the fuel economy in terms of use are to keep the technical condition of the concrete mixer truck in good condition and the correct driving operation. Mainly as follows:

a. Correct technical maintenance and adjustment

The adjustment and maintenance of the mixer truck will affect the performance of the engine and the driving resistance of the mixer truck, and have a considerable impact on the fuel consumption per 100 kilometers. Therefore, the correct technical maintenance and adjustment will have a great impact on the fuel economy of the mixer truck.

First of all, keep the engine in good technical condition. Maintain and inspect the oil supply system, air intake system and lubrication system to prevent oil leakage, and timely check the precipitation and impurities in the filter. When the air filter is not smooth, the fuel consumption will increase by about 3%. “Three filters” for maintenance to maintain the correct temperature of the engine cooling system.

In terms of chassis, it is necessary to strengthen the maintenance and adjustment of each assembly to maintain proper sliding ability and reduce fuel consumption. The sliding ability of the cement tanker is often evaluated by the sliding distance, and the sliding distance can be used to check the technical condition of the chassis.

The positioning of the front wheel of the mixer truck, the adjustment of the gap of the brake, the tire pressure, the tightness of each bearing, the clearance of the moving friction part and the lubrication quality will have a great impact on the movement resistance of the mixer truck, and must be adjusted and maintained according to regulations.

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Details can be accessed by clicking here:https://www.ly-cimc-linyu.com/a/news/factors-affecting-the-fuel-consumption-of-concrete-mixer-trucks.html

The role of storage shelves in the logistics warehouse is very important, which not only affects the production efficiency of the enterprise, but also affects the management efficiency of the warehouse. The premise of how to effectively use storage shelves is to choose a racking system that suits you, so how do we choose a suitable storage rack?

First, we need to understand the principles of warehouse shelf design

1. Design principles of warehouse shelves

1. Increase the storage space and maximize the use of space. Every enterprise warehouse has its fixed cost. How to maximize its economic benefits in this space is an important principle of warehouse shelf design.

2. Cargo-oriented, in line with the principle of storing goods

In the final analysis, warehouse shelves are shelves for storing goods. Naturally, warehouse shelves suitable for storing goods should be designed. Therefore, it is necessary to have a comprehensive understanding of the cargo itself, including data such as shape, size, and weight. The data can be provided by the warehouse or measured on-site by the shelf supplier.

3. Fully understand the warehouse environment and related equipment principles

(1) Warehouse structure: including warehouse area, warehouse type, warehouse channels, warehouse effective total height, warehouse column position, warehouse floor, warehouse fire-fighting facilities, etc.;

(2) Related equipment: forklifts, stackers, elevators, etc. It should be noted that the forklift needs to know the required aisle, turn length, etc.

4. The principle of effective circulation of goods and effective management

(1) The management method of goods: carefully listen to the purchasing enterprise’s management method of goods, and formulate a plan for the reasonable arrangement of warehouse shelves;

(2) Mode of goods circulation: including manual or mechanical handling of goods, aisle position, first-in, first-out, whole-in, whole-out, etc.

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Details can be accessed by clicking here:https://www.etegreen.com/blog/storage-shelf-choose/

Hydraulic excavators generally use single-row four-point contact ball-type internal gear slewing bearings. During the excavator operation, the excavator slewing bearing bears complex loads such as axial force, radial force and tipping moment, and its reasonable maintenance is very important. The maintenance of the excavator slewing bearing mainly includes the lubrication and cleaning of the raceway and the inner gear ring, the maintenance of the inner and outer oil seals, and the maintenance of the fastening bolts. Now from these seven aspects will be described in detail.

1. Lubrication of raceways

Slewing bearing rolling elements and raceways are easy to damage and fail, and their failure rate is high. During the use of the excavator, adding grease to the raceway can reduce the friction and wear among the rolling elements, the raceway and the spacer. The space of the raceway cavity is small, and the resistance to filling grease is large, so manual filling with a manual grease gun is required. The lubricating oil nozzles of the slewing bearing raceway are generally distributed at the position of the outer wall of the slewing bearing.

The raceway cavity is generally lubricated with 2# file-based grease, and the grease filling cycle is generally 100h. Under special working conditions such as high dust, high temperature, and continuous operation, the filling cycle should be appropriately shortened. When adding grease, it is necessary to rotate the slewing bearing, and add it about once every 15°~25°. When filling, pay attention to observe the outer sealing ring of the slewing bearing. When you see grease seeping out from the outer sealing ring, stop filling.

When the raceway cavity is filled with grease, bad filling methods such as “refueling in static state” and “single-point oiling” should be avoided, because the above-mentioned bad filling methods will cause local oil leakage of the slewing bearing, and even cause the oil seal of the slewing bearing to become permanent. Damaged, resulting in grease loss, impurity intrusion, and accelerated raceway wear. Be careful not to mix different types of grease to avoid premature failure.

When replacing the seriously deteriorated grease in the raceway of the slewing bearing, the slewing bearing should be rotated slowly and uniformly while filling, so that the grease can be filled evenly in the raceway. This process can not be rushed, it needs to be done step by step to complete the metabolism of grease.

2. Maintenance of the gear meshing area

Open the metal cover on the base of the slewing platform to observe the lubrication and wear of the ring gear of the slewing bearing and the pinion of the slewing motor reducer. A rubber pad should be placed under the metal cover and fastened with bolts. If the bolts are loose or the rubber gasket fails, water will seep from the metal cover into the lubricating cavity (oil collecting pan) of the rotating inner gear ring, causing premature failure of the grease, reduced lubrication effect, and increased gear wear and corrosion.

The method of replacing the grease in the lubricating cavity of the ring gear is as follows: first, use the working device to support the excavator, and the operator goes under the crawler frame of the excavator and opens the metal cover; secondly, drop the excavator to the ground and start the excavator Do the rotating action for about 10 laps, and the failed grease can be exhausted. The lubricating cavity of the ring gear of the slewing bearing is also filled with 2# file base grease. The replacement cycle is generally 2000h, and the filling amount should be determined according to the model of the excavator.

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Details can be accessed by clicking here:https://www.excavatorbearing.com/a/bearing-knowledge/maintenance-of-excavator-slewing-bearing.html

The overhaul of the tractor is inseparable from the overhaul of the clutch components. In order to improve the maintenance quality of the tractor, the overhaul methods and standards of the main components of the tractor clutch are introduced in detail.

The tractor clutch is composed of four parts: the active part, the driven part, the pressing mechanism and the operating mechanism. The main component of the active part is the driving disc; the main component of the driven part refers to the driven disc with friction linings riveted on both sides; the main components of the pressing mechanism are the pressing spring, pressing lever, and pressing rod bracket; The main components are separation lever, separation bearing, etc. The following tractor clutch manufacturers talk about the maintenance of the main components of the tractor clutch based on actual experience.

Overhaul of drive and driven discs

The main damage of the active disk is wear, scratches, burns and cracks on the friction surface; warpage and deformation of the friction surface. When the thickness of the active disc is 18±0.1 mm, the surface groove depth exceeds 0.50 mm, the arch deformation exceeds 0.30 mm, and the flatness tolerance exceeds 0.12 mm, it should be ground or flat. However, after polishing, its thickness is not less than 16±0.40 mm. If the active disk is cracked or too thin, it should be replaced with a new one.

The driven disc is the most vulnerable part of the clutch. The main damage is wear, hardening, burns, cracks on the surface of the friction plate, oil stains on the surface (dry type), loose friction plate, warping and deformation of the driven disc, fracture of the steel plate, loose riveting between the steel plate and the disc, spline holes wear, etc. It can be determined by measuring the depth of the rivet head with a vernier caliper. The burial depth of the rivet head shall not be less than 0.3 mm, otherwise, use a new friction plate. If the friction plate is seriously worn or there are more than two cracks and fall off, and the burnt surface is large and deep, the new plate should be riveted again. If there is a slight oil stain on the friction plate, it can be burned off with the flame of a blowtorch, or cleaned with gasoline, and the slight burnt surface can be polished with sandpaper.

When replacing the new piece to remove the old piece, use a drill bit 0.40-0.50 mm smaller than the diameter of the old rivet to drill out the rivet head, and then gently punch out the old rivet and remove the old piece. Use a wire brush to remove dust and rust from the driven disc, and check other parts of the driven disc. The warpage of the driven disc steel plate will cause the clutch to vibrate and wear unevenly when starting, so its warpage should be checked. The warpage of the driven disc steel sheet is also called circular runout or yaw. It can be installed on the inspection frame and measured at the outermost edge of the driven disc with a dial indicator. The circular runout limit is 0.80 mm. If it exceeds the limit, it can be calibrated by cold pressing with a special clamp;

Repair of elastic push rods

The main damage of the elastic push rod is the weakening of the elastic force, the reduction of the hole center distance, the wear of the support hole, and the breakage of the elastic push rod. After the elastic force of the elastic push rod is reduced, it is heated to 780 ~ 810 ° C, quenched in oil, and then heated to 450 ~ 475 ° C for tempering.

When the center-to-center distance of the elastic push rod becomes smaller, the original center-to-center distance can be restored by thermal deformation method. between the mouth. Increase the center distance of the holes, and then perform quenching and tempering according to the above method. When the center distance of the pin holes is enlarged, care should be taken to make the center lines of the two pin holes parallel. When the fitting clearance of the pin hole of the elastic push rod is greater than 0.50 mm, it can be repaired by the maintenance dimension method. The maintenance size can be increased by 1 mm, and the fitting clearance between the pin and the hole is 0.12 mm.

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Details can be accessed by clicking here：https://www.syclutch.com/news/overhaul-of-the-main-parts-of-the-clutch.html