Hydraulic excavators generally adopt single row four point contact spherical internal gear slewing support. In the work of excavator, the slewing support bears the complicated loads such as axial force, radial force and overturning moment, so its reasonable maintenance is very important. The maintenance of slewing support mainly includes lubrication and cleaning of raceway and inner gear ring, maintenance of inner and outer oil seals and maintenance of fastening bolts.
1. Race lubrication
The rolling body and raceway of the slewing support are easy to damage and fail, and the failure rate is high. During the use of the excavator, adding grease to the raceway can reduce the friction and wear between the rolling body, raceway and isolation block. Due to the narrow space of raceway cavity and high grease resistance, manual grease gun is needed. The lube nozzles of the raceway of the slewing bearings are generally distributed on the outer wall of the slewing bearings. The cavity is generally lubricated with 2# lithium grease, and the lubrication cycle is generally 100h. Under special working conditions such as dust, high temperature and continuous operation, the filling cycle should be appropriately shortened. When adding grease, it is necessary to rotate the slewing support, turning about 15°~25° each time. When filling, pay attention to the outer seal ring of the slewing ring. Stop filling when the grease is seen to seep out of the outer sealing ring for one week. When filling the raceway cavity with grease, undesirable filling methods such as "static refueling" and "single refueling" should be avoided. This is because the above poor oil filling method will cause local oil leakage of the rotary support, or even cause permanent damage to the rotary support oil seal, leading to grease loss, foreign body invasion, raceway accelerated 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 rotary support, the rotary support should be slowly and evenly turned during the filling process to make the grease in the raceway evenly filled. This process can not be rushed, need to complete the metabolism of oil step by step.
2. The method to replace the grease in the lubrication chamber of the inner ring gear is as follows: first, the working device is used to support the excavator. The operator enters the crawler frame of the excavator and opens the metal cover. Next, put the excavator down to the ground and start the excavator, making it rotate about 10 times to expel the faulty grease. 2# lithium grease is also filled in the lubrication chamber of the inner gear ring of the rotary bearing. The replacement period is generally 2000h. The amount of filling shall be determined according to the type of excavator.
3. Maintenance of internal and external oil seals The inner and outer oil seals of the slewing bearings are made of rubber seals with low pressure. The outer oil seal is located on the lower surface of the inner ring of the slewing ring, which is used to prevent the outer sand particles from entering the raceway and causing the rolling body and raceway to wear. The grease in the oil chamber enters the raceway chamber.
4. Maintenance of fastening bolts Some operators believe that the greater the strength of the slewing support bolt, the better the force. In fact, when the tensile force of the bolt exceeds the tensile strength of the bolt itself, the pre-tightening force cannot be formed. In order to ensure the reliability of the bolts, they should be tightened according to the bolt regulations
5. Gear clearance adjustment When assembling the slewing support gear and the output gear of slewing motor reducer, the tooth gap should be adjusted by using the highest point of the radial runout of the slewing support section. Select meshing clearance according to the size of gear modulus. Under normal conditions, the meshing clearance increases with the number of teeth. The maximum point of radial runout of the inner tooth distance of the excavator slewing support, the clearance Sh value of gear tooth side of the slewing motor reducer is ≥0.03m (m is the gear modulus) Tightening torque of this model. Bolts with a strength of 10.9 should be selected. Flat washers of steel 45#, quenched and tempered, tempered and hardness HRC39 shall be used. Do not use spring washers.
6. Do not flush the slewing support with water
Do not use water for non-washing of sleuth bearings http://www.andybly.com, so as not to flush water, impurities, dust into the sleuth bearings raceway, causing raceway corrosion, rust, so that the grease dilution, damage the lubrication state, grease deterioration and failure; Avoid any solvent contact with the rotary support oil seal to prevent corrosion. In short, after the excavator is used for a period of time, its slewing support is easy to produce noise, impact and other faults. Operators should pay attention to observation, timely inspection, troubleshooting. Only the correct and reasonable maintenance of the slewing support can ensure its normal operation, give full play to its performance and extend its service life. Jiangsu warm intelligent equipment co., LTD. Cover mechanical processing, slewing bearing, jiangsu changzhou slewing bearing, etc., is a professional engaged in rotary bearing technology development and production manufacturers, the company production, processing 30 tons - 3000 tons of gold, silver, iron, lead and zinc and other non-ferrous metal ore dressing equipment, production of various series of slewing bearing, wheel bearing, rotary gear reducer, rotation drive, a diameter of 200 to 3000 mm, with high precision, good operation, safe and reliable quality, etc. This article by jiangsu warm intelligent equipment co., LTD compiled and released, if reprinted, please indicate the source: http://www.andybly.com