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

The valve bag made by the bottom paste machine has the characteristics of good moisture resistance, reasonable cost and high production efficiency. It is suitable for the packaging of various powdery colloidal products. effect.

Application scope of valve bag

1. Industrial aspects

It is a powder product packaging for building materials powder, chemical raw materials, pharmaceutical additives, cement, quartz sand, cellulose, polyvinyl alcohol, dispersible latex powder and other materials. Due to the particularity of the product, the packaging bag must meet the requirements of moisture-proof, moisture-proof, dust-proof, easy to stack, not easy to slip, not easy to damage, impact resistance and so on!

2. Agricultural products

The valve bag is an ideal packaging container for powder, granular, flake, flocculent and thick materials such as fertilizers and pesticides used in agricultural production. It is widely used in industrial and agricultural packaging. The valve bag can realize high-speed filling, flexible valve port, neat stacking, strong firmness, no dust leakage, packaging, moisture-proof and moisture-proof. It is a packaging that is particularly popular and widely used by businesses. The use of the packaging bag saves production time and reduces labor costs for enterprises.

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Details can be accessed by clicking here:https://www.lyhuatianm.com/products-information/application-range-of-valve-bag.html

Linear vibrating screen structure and functional description of each part, linear vibrating screen is mainly composed of screen box, screen frame, screen mesh, vibrating motor, motor base, vibration damping spring, bracket, etc. The following vibrating screen manufacturers will introduce each linear vibrating screen in detail Parts composition, installation, use and maintenance work.

Structural composition of linear vibrating screen

1. Screen box: It is welded by several steel plates of different thicknesses. It has certain strength and rigidity and is the main part of the screening machine.

2. Screen frame: made of pine or wood with small deformation, it is mainly used to keep the screen flat and achieve normal screening.

3. Screen: There are several kinds of screens such as low carbon steel, brass, bronze, stainless steel wire.

4. Vibration motor (please refer to the vibration motor operation manual for operation and maintenance methods).

5. Motor base: install the vibration motor. Before use, the connecting screw must be tightened, especially three days before the trial of the new mesh screen machine, it must be tightened repeatedly to avoid accidents caused by loosening.

6. Damping spring: prevent vibration from being transmitted to the ground and support the overall weight of the screen box. When installed, the spring must be perpendicular to the ground.

7. Support: It consists of four columns and two channel steels to support the screen box. When installing, the columns must be perpendicular to the ground, and the channels under the two columns should be parallel to each other.

Preparations for installing linear vibrating screen

1. Check whether the motor logo meets the requirements.

2. Measure the insulation resistance with a 500-volt megger, and dry the stator winding at a temperature not exceeding 120.

3. Check the motor fasteners and beware of loosening.

4. Check whether the motor surface is damaged or deformed.

5. Check whether the rotation is flexible. If there is any abnormality, it should be excluded.

6. Check whether the power supply is out of phase, and run for 5 minutes with no load.

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Details can be accessed by clicking here:https://www.hsd-industry.com/news/linear-vibrating-screen-installation/