Abstract] This paper introduces a on-site repair process for bearing wear of Spencer high-speed multi-stage centrifugal fan with rotating speed of 2900 r/min, and analyzes the causes of fan wear, and puts forward a process for on-site repair using Fujitsu Blue < polymer composite materials with special tooling, which will last after repair. The tracking effect is good.
[Key words] fan shaft wear; fan; bearing bit wear; Shi bin Sha
1, equipment introduction
The multi-stage centrifugal fan is a multi-stage, single-suction, double-support structure composed of rotor, casing, air inlet, air outlet, bearing seat, sealing group, muffler, motor, control system, etc. (see Fig. 1); the motor and blower are mounted on the base and pass between them.
2. Field repair of multi stage centrifugal fan shaft wear
2.1 wear condition of multistage centrifugal fan shaft
The vibration value of an imported Spencer multistage centrifugal fan in a chemical enterprise was too large and the rotating speed was 2900 r/min. After disassembly, the shaft wear problem was found on the thrust side of the fan. The wear location was the installation surface of angular contact bearing and ball bearing, the wear amount was about 0.25 mm on one side, and the shaft diameter was about 65mm. The number is: 7313WN/T313KS; deep groove ball bearing is 7313WN/P313KS.
2.2 equipment problem analysis
There are many reasons for shaft wear, but the most important reason is the metal characteristics used to manufacture shaft, although the metal hardness is high, but poor concession (after deformation can not be restored), poor impact resistance, poor fatigue resistance, so easy to cause adhesion wear, abrasive wear, fatigue wear, fretting Wear, most of the shaft wear problems are not easy to detect, only in the case of high temperature, jumping amplitude, abnormal sound, most of the shaft has been worn seriously, resulting in machine shutdown.
2.3 field repair technology for wear of multi stage centrifugal fan shaft
2.3.1 The traditional way to deal with the wear of shafts and inner holes is to transport the shafts to the machine repair plant for repairing and welding. The repairing welding machine itself is easy to cause local thermal stress on the surface of the shafts, resulting in the hidden danger of shaft breakage. The demolition, transportation and installation of the utility model have a long repair time and high comprehensive repair cost.
2.3.2 Fuxing blue polymer composite repair process. In order to improve the repairing precision, the repairing die was redesigned to ensure the repairing effect and precision, and the repairing precision was guaranteed to the maximum extent.
2.4 field repair of shaft wear of multistage centrifugal fan
2.4.1 Surface treatment: Firstly, the abrasion position is baked to remove the grease infiltrated into the metal micropores.
2.4.2 pitting: 4-6 pitting on the circumference of the shaft to increase the adhesive force of the material.
2.4.3 grinding: use sandpaper to grind the worn position and clean it with alcohol or acetone.
2.4.4 Hollow test mold: assemble the mold to the repairing part, observe the clamping condition of the mold, and then brush and paint the stripping agent after disassembly.
2.4.4 blend material: mix 2211F material proportionally and stir until no color difference.
2.4.5 coating material: 2211F material is used to fill the worn position and slightly larger than the amount of wear.
2.4.5 assemble the mold and wait for the material to solidify.
After the 2.4.5 material is solidified, the mold is removed and the material is applied again to assemble the bearing.
2.5 field repair of shaft wear of multistage centrifugal fan
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