The connection dimensions of boom and platform and boom and stick are exactly the same as the corresponding dimensions of the whole boom, so as to ensure that the two types of boom can be interchanged. The piston rod end hinge shaft of this kind of boom cylinder is similar. It adopts double support short shaft structure, but there is no spherical plain bearing, and the spherical plain bearing is also simplified as bearing bush. The form and position tolerance of each axis is mainly ensured by processing technology. Precautions are as follows:
1. The connection dimension between the lower boom and the rotary platform must be the same as that of the integral boom.
2. The connection dimension between the upper boom and the stick must be the same as that of the integral boom.
3. The size of boom cylinder and stick cylinder must be the same as that of integral arm.
4. The locking force of combined arm cylinder must meet the requirements of bucket digging force.
5. The connecting support seat and side plate of lower boom and boom cylinder must have enough strength.
6. In order to prevent the bucket from touching the cab when the upper boom retracts, the length of the upper boom should be increased appropriately.
