1、 Purpose

Suitable for quality control of gearbox assembly during the assembly process.

2、 Content

To ensure the quality of gearbox assembly, a fixed assembly site and platform should be provided, and professional assembly personnel should be responsible for assembly.

（1） Preparation work before assembly

Firstly, clean up the assembly site and platform, and collect all processed and standard parts according to the detailed assembly drawing. And it should be classified and placed on the workstation equipment. When the surface roughness is above, soft materials should be padded, and the position of the support point should be considered for the placement of easily deformed parts.

1. Cleaning

1) Remove all burrs and burrs from all parts before assembly;

2). Before assembly, all parts should be cleaned with kerosene at least three times until they are completely clean;

3) Bearings can be cleaned with gasoline. If the rust proof grease is thick, clean oil can be heated (with an oil temperature not exceeding 100 ° C) for cleaning. After the rust proof grease dissolves, it can be removed and cooled before cleaning;

4) Remove all debris from the box and apply two layers of paint on the inner wall that are not corroded by engine oil; The oil holes, screw holes, air holes, and all machined surfaces on the box must be cleaned thoroughly. The oil holes and air holes should be sealed with adhesive tape or plastic to prevent dirt from entering;

5) All gear meshing, bearing fitting, shaft pin and hole fitting must be coated with clean lubricating oil on their surfaces during assembly;

6) Various sealing felt gaskets should be soaked in oil before assembly. Soft steel cardboard should be softened by soaking in hot oil. The copper pad should be annealed (heated to 600 ° -650 ° C and then cooled in water).

2. Check

1) Recheck the fitting dimensional tolerances of all parts, select suitable parts according to the assembly interference tolerance required by the drawing, and mark them in groups.

2) Check that the chamfers and arcs on the matching holes and shafts match. To avoid interference during assembly and the formation of unavoidable assembly gaps.

3) Check the fit dimensions of the journal, housing, and bearings, and ensure that the bearing model is consistent with the drawing.

4) Check that the specifications and models of the seals are consistent with the drawings and are not damaged.

3. Assembly

1). The box is assembled on the platform and aligned with the horizontal section of the box. If shims are needed, they should be placed in the position of the anchor bolt holes.

2) The assembly of gears and shafts adopts hot or press fitting. When using hot fitting, attention should be paid to eliminating assembly gaps during the cooling process of the workpiece. The reference surface of the assembled gear should be close to the shaft shoulder, and the feeler gauge should not be inserted at the end face of the shaft shoulder. The axial position of gear meshing can be adjusted through the positioning sleeve on the outer end of the bearing. The umbrella gear assembly is aligned with a small head.

3) When assembling rolling bearings using hot installation, the heating temperature should be between 80-100 ° C. The inner ring of the bearing should be tightly fitted, and the plug gauge should not be inserted into the shoulder end face of the shaft.

4) Apply liquid sealant to the partition surface and shaft end cover of the box according to relevant regulations.

5) The bolts for the split surface of the box should be tightened with a torque wrench according to the standard pre tightening force. When pre tightening bolts, attention should be paid to uniformity and symmetry. Apply 40% of the pre tightening force for the first time, 70% for the second time, and 100% for the third time.