Industrial reducer plays the role of matching speed and transferring torque between prime mover and actuator. It is a kind of deceleration transmission device, which is widely used in mechanical equipment. This article shares the installation points of industrial reducer, the common faults in the process of reducer use, and the maintenance and assembly precautions of reducer.

1. Installation points of reducer

The installation of reducer is a delicate and complex work with high technical requirements. In operation, it is necessary to strictly abide by the operating procedures and design data. The general installation sequence is: equipment leveling and alignment, cleaning and assembly, adjustment and commissioning.

(1) Before installation and use, the mounting shaft of the reducer shall be cleaned, and the mounting shaft shall be checked to see if there are bumps and dirt. When the reducer is installed obliquely, it should be ensured that the bearing of the highest gear shaft is lubricated by the gear oil in the box, and the gas in the box can be discharged from the highest position of the box.

(2) When the industrial reducer is assembled with the actuator and prime mover, the connecting flange shall be cleaned and polished to ensure the flatness of the straight joint of the connecting flange, and all bolts around the flange shall be matched and tightened.

(3) The assembled transmission elements (coupling, sprocket) should be kept in rotation balance, so as to avoid the disallowed radial force or axial force. Generally, assembly fixture and internal thread of shaft end are used to press the transmission parts with bolts, otherwise the internal parts of reducer may be damaged.

(4) Reducer installation must be rigidly fixed on a solid horizontal foundation or vertical frame, and be leveled. The coaxiality of prime mover, coupling, reducer and actuator must be consistent, so as to avoid damage caused by additional stress on input and output shafts and bearings caused by running deflection.

The coaxiality of two connected shafts should be controlled within φ Within the range of 0.1 mm, there should be 2-8 mm clearance between the two shaft extension end faces. The clearance value depends on the specific situation of the equipment connected with the reducer. It should not only ensure sufficient load transfer capacity, but also ensure that the reducer bearing will not be subjected to additional axial force.

In order to avoid the deflection of the main shaft of the working machine and the additional force on the bearing of the reducer, the distance between the reducer and the working machine should be as small as possible without affecting the normal operation, and its value is 5-10mm.

(5) Add gear oil: the grade of oil should be the recommended value of reducer, or the oil completely equivalent to the recommended oil should be used. And the oil quantity should be correct, and each reducer should be attached with a label indicating the level and quantity of recommended oil. The oil mirror is the oil level display mirror of the reducer. On one side of the reducer, when filling oil, the oil level should reach the upper and lower position of the middle of the oil mirror.

The importance of correct oil filling: in the splash lubrication reducer, when the load is close to the thermal power, the correct oil filling is particularly important. In some cases, the operating temperature may rise to 15-20 ℃ above the normal temperature only due to the addition of 15% more oil, which will reduce the lubricating capacity of the oil and cause serious damage to the reducer. When the oil level is lower than the oil level indicated by the mark, the gear can not get oil, which makes splash lubrication impossible.

2. Common fault analysis

Due to the bad operating environment of industrial reducer, there are often wear, leakage and other faults, which are shown in the following aspects:

(1) The bearing chamber of reducer is worn.

It also includes the wear of the housing bearing box, the bearing chamber of the inner hole of the housing and the bearing chamber of the gearbox. This kind of situation is mainly due to the improper adjustment of parallelism and coaxiality of each shaft when installing the shaft and bearing, the deflection force (radial or axial) or abnormal vibration of the box during long-time operation, resulting in certain wear of the bearing chamber caused by the bearing force of the shaft and bearing.

(2) The gear shaft diameter of reducer is worn.

The main wear parts are shaft head and keyway. This kind of fault is caused by frequent overload start-up during operation and material problems of some parts.

(3) The bearing position of the transmission shaft of the reducer is worn or the bearing is faulty.

Incorrect assembly will not only accelerate the wear of bearing, but also cause fracture and high temperature seizure. Especially for the bearings that can not be self-aligning, when the machining accuracy of the journal or bearing seat hole is poor or the installation is improper, and the deflection of the shaft is too large, the inner and outer rings of the bearing will tilt each other, so that the working load distribution of the bearing is uneven, and the pressure concentration will be damaged prematurely.

(4) There is leakage on the joint surface of reducer.

The oil leakage at the joint surface of the gearbox body and the bearing end cover is mainly due to the mistakes in the application process of the sealing gasket or sealant on the joint surface; Improper maintenance process. During equipment maintenance, oil leakage will be caused due to incomplete removal of dirt on the joint surface, improper selection of sealant, reverse installation of seals, and untimely replacement of seals, which can be avoided after strengthening the requirements of assembly process.

(5) Gear tooth failure of reducer.

The common failure forms of gear teeth are: broken gear teeth and tooth surface damage. Tooth fracture usually occurs at the root of the tooth, because the bending stress at the root of the tooth is the largest and there is stress concentration. The damage of tooth surface can be divided into fatigue pitting, abrasive wear, gluing and plastic deformation.

The measures to prevent the failure of gear teeth are as follows: improving the requirements of tooth surface hardness and surface roughness; Choose the lubricant with high viscosity; Supply enough lubricating oil and keep it clean; Avoid frequent starting and serious overload and impact; Improve assembly quality and strengthen maintenance management.

3. Maintenance and assembly precautions

Whether the gear meshing of industrial reducer meets the requirements, whether the contact surface is good, and whether the assembly clearance of various parts of bearing is good are the signs of the assembly and repair quality of reducer gear.

(1) When checking the gear, if the tooth surface is found to be worn unevenly, with traces or partial spalling, the center distance of the gear, the unevenness of each shaft, the gear meshing clearance, the levelness, coaxiality and contact of each bearing, the quality of lubricating oil, whether other metal or non-metal objects fall into the gearbox, and whether the gear key and nut are loose shall be checked immediately. The problems found in the inspection must be dealt with in time, and must not be forced to operate.

(2) During the inspection, if a tooth surface spalling is found, its area does not exceed 30% of the effective joint area of the gear. When other parts are normal, it can continue to be used, but it is necessary to focus on regular inspection for changes. When the tooth surface spalling is increasing and the running condition is deteriorating, it should be replaced immediately.

(3) When it is found that the wear degree of the two gears is very different, they can not continue to be used together. It is only temporary to replace the pinion, so they should be replaced in pairs as far as possible. In addition to the repair or replacement of the reducer, shaft and gear, the worn or damaged rolling bearing or sliding bearing bush shall be replaced, the clearance shall be checked, the box and the parts installed in the box shall be cleaned, and the lubricating oil shall be replaced.

(4) After cleaning the reducer, be sure to tighten the screw plug of oil drain hole, and add enough lubricating oil according to the required lubricating oil brand. When repairing the reducer, it is necessary to prevent foreign matters from falling into the box.

(5) The sealing quality of the joint surface between the upper and lower boxes of the reducer is the key to prevent oil leakage. Generally, the connection between reducer box and box cover or flange can be sealed with gasket or glue. Gasket materials are cardboard, copper, lead, oil resistant rubber, etc.

When the contact area to be sealed is large and the joint surface is rough, the thickness of the gasket should be increased. When installing the gasket, it must be pressed tightly. If it is found that the gasket has lost its elasticity or damaged, it must be replaced.