An assembly method of cone interference fit is described. The conical end of the contained part is inserted into the conical hole of the containing part to form an interference fit. The conical end of the included part is installed into the conical hole of the containing part, and the vertical distance h between the bottom surface of the included part and the bottom surface of the conical hole is measured; the included part is taken out, and the bottom of the containing part is placed on the working surface of a supporting beam The adjustment block used to support the contained parts is set on the working face of the beam, and the vertical height between the upper end face of the adjusting block and the working face of the supporting beam is H-P; after freezing and heating the contained parts, after assembly, when the containing parts and the contained parts reach the same temperature, the support beam is removed to complete the interference assembly. The assembly method of the invention is to change the temperature difference between the contained part and the containing part, so as to produce the required assembly gap between the containing part and the contained part, and realize the cone interference fit assembly of the included part and the containing part through the positioning of the supporting beam.
With the rapid development of mechanical manufacturing technology, there are more and more products that transfer torque and axial force by friction produced by cone interference fit. In order to get a larger transmission torque, it is necessary to have a larger interference. With the development of industry, mechanical equipment is developing towards large-scale, the basic size of mechanical equipment parts is becoming larger and larger, and the interference amount of interference connection increases with the increase of basic size.
Interference assembly process includes press fit, hot fit and cold fit. In addition, the larger the pressure press and pressure machine parts are required to be assembled, the greater the resistance is required for the assembly of large-scale hydraulic press parts.
(2) Hot charging is to increase the size of the enclosure by heating medium such as oil and air, and create a fit gap with the contained part. When the normal temperature is restored, the enclosed part can be held tightly, so as to realize the smooth assembly. Because of the small thermal expansion coefficient of metal, even if the temperature rises to about 200 ° C, the expansion of pore size is very limited. If the clearance is too small and the sleeve and shaft are not assembled in place, the hole diameter of the sleeve will shrink, which is easy to lock up and be in a dilemma. The heating temperature of the enclosure will be very high, which may cause the thermal stress deformation of the enclosure and affect the quality accuracy of other finishing surfaces of the enclosure.
(3) However, if only using the cold assembly technology, the cooling temperature requirement of the contained parts will be very low. The internal and external defects of the parts, especially the cracks and corner holes, will expand during the cooling process and cause hidden dangers or directly lead to the parts cracking failure When the temperature is lower than the brittle transition temperature of the material, the stress of the contained part will appear in the assembly process, and the serious stress may lead to the fracture of the part. Moreover, it is difficult for the current cooling equipment to reach the cooling temperature required for cold charging. For example, the connection form of the main shaft and the frame of the crusher is cone interference fit, and the hot assembly technology of only heating the housing of the containing part or cooling the main shaft of the contained part can not meet the assembly clearance requirements.
It can meet the assembly clearance requirements of cone interference fit, and provide an assembly method of cold fitting and hot fitting.
The invention relates to an assembly method of conical surface interference fit, in which the conical end of the contained part is inserted into the conical hole of the containing part to form an interference fit, which comprises the following steps:
- Step 1, the conical end of the contained part is installed into the conical hole of the containing part, when the peripheral surface of the conical end and the conical hole are inside When the contact rate of the peripheral surface is not less than 80%, take a depth micrometer to measure the vertical distance h between the bottom surface of the contained part and the bottom surface of the conical hole;
- step 2: take out the contained part, and place the bottom of the containing part on the working face of a supporting beam, and work on the supporting beam An adjusting block for supporting the contained part is arranged on the surface, and the vertical height between the upper end face of the adjusting block and the working face of the supporting beam is h = H-P, where p is the target movement amount of the relative movement of the contained part and the containing part along the axial direction of the conical hole during interference assembly;
- Step 3: put the contained parts taken out in step 2 into an industrial freezer for freezing, and the freezing temperature in the freezer can be automatically adjusted.