In traditional jaw crushers, the frame accounts for a significant proportion of the total machine weight (approximately 50% for cast frames and around 30% for welded frames). Moreover, its manufacturing cost constitutes 50% of the overall production expenses, substantially influencing the equipment's price. This article compares the differences between integral and modular frames in terms of weight, material consumption, cost, transportation, installation, and maintenance. Let's explore these aspects together!

　1. Structural Types of Jaw Crusher Frames  

Jaw crusher frames can be categorized by structure into integral frames and combined frames, and by manufacturing process into cast frames and welded frames.

　　1.1 Overall Frame

　Traditional integral frames are produced entirely through casting or welding. Due to difficulties in manufacturing, installation, and transportation, they are unsuitable for large jaw crushers and are primarily used for small and medium-sized jaw crushers.

　　1.2 Modular Rack

　　The modular rack adopts a weldedfree frame structure with a modular design. It consists of two side plates securely bolted to the front and rear wall panels (cast steel components) via precisionmachined fastening bolts. The crushing force is borne by embedded pins on the sidewalls of these panels. The left and right bearing housings feature an integrated design and are also tightly connected to the side plates using bolts.

　　2. Comparison of Processability Between Modular Racks and Integrated Racks

　　2.1 The modular rack is lighter in weight and consumes less material compared to the integrated rack.

　　The modular frame does not require welding, allowing the use of highstrength alloy steel plates with higher carbon content and greater tensile strength (e.g., Q345), which enables appropriate reduction in plate thickness.Under the premise of ensuring comparable strength and stiffness of the frame, a comparative experimental analysis was conducted on the weight of integral frames and modular frames for three models of crushers, as shown in the table below:

　　Source: Development & Innovation of Machinery & Electrical Products

　　The comparison in the table above shows that the modular rack can reduce material consumption (weight) by 17% to 24% compared to the welded rack.

　　2.2 The combined rack system requires relatively lower investment costs for plant construction and processing equipment.

　　The modular frame can be divided into major components such as the front wall panel, rear wall panel, and side panels for separate processing. Each individual part is lightweight, requiring lower crane capacity, whereas an integral welded frame demands significantly higher crane capacity (nearly four times greater). Taking the PE1200X1500 as an example: the modular frame and integral welded frame require crane capacities of approximately 10 tons (single hook) and 50 tons (double hook) respectively, with costs around ¥240,000 and ¥480,000. This alone can save approximately ¥240,000 in expenses.

　　The entire welded frame must undergo annealing and sandblasting after welding, which requires the construction of annealing furnaces and sandblasting roomsa significant investment. In contrast, modular frames do not necessitate such expenditures.   Secondly, modular frames entail lower facility investment costs compared to monolithic frames. This is because they require lower crane tonnage and impose less stringent demands on factory columns, support beams, foundations, and building height, as long as the design and operational requirements are met.

　　2.3 Short production cycle and low manufacturing costs.

　　The individual components of the modular rack can be processed simultaneously on different equipment without being affected by the progress of preceding operations. Assembly can commence once all parts are machined. In contrast, for an integrated rack, all components must first be completed before alignment and welding can begin.

　　For example, the bevels on the three mating surfaces of the rib plate require machining, and the inner bore of the bearing housing along with its three mating surfaces must undergo rough machining before assembly. After the entire frame is welded, it must undergo annealing treatment before precision machining (such as bearing bore machining) can proceed. This process involves more steps than a modular frame assembly, resulting in longer machining time. The larger and heavier the frame's external dimensions, the more time the process will require.

　　Taking the labor costs (based on actual working hours) and material consumption for each process of the integral frame and combined frame of the PE750X11060 crusher as an example, the calculations are shown in the table below:

　　Source: *Development and Innovation of Mechanical and Electrical Products*   The data indicates that compared to a monolithic frame, a modular frame can reduce machining time by approximately 30% and lower manufacturing costs by 13% to 20%.

　　2.4 Reduce transportation costs.

　　Transportation costs are calculated based on tonnage. The modular rack is approximately 17% to 24% lighter than the integrated rack, correspondingly saving about 17% to 24% in transportation costs compared to welded racks.

　　2.5 Facilitates underground installation.

　　Each major component of the modular rack can be transported separately to the underground mine site, where the final assembly of the crusher is completed. This feature significantly reduces construction time and saves costs. Underground installation only requires standard lifting equipment and can be completed in a relatively short period.

　　2.6 Easy to repair with low maintenance costs.

　　Since the combined frame is assembled from four components, when a part of the crusher frame is damaged, it can be repaired or replaced based on the extent of the damage without needing to replace the entire frame.

In contrast, for a onepiece frame, apart from the reinforcing ribs which can be repaired, issues such as torn front or rear wall panels, side plates, or deformed bearing housings are generally irreparable. This is because torn side plates inevitably cause displacement of the bearing housing, leading to misalignment of the bearing bores. In such cases, welding cannot restore the bearing housing to its original positional accuracy, and the only solution is to replace the entire frame.

　　SummaryThe frame of a jaw crusher is subjected to significant impact loads during operation, necessitating the following technical requirements:

① sufficient rigidity and strength;

② lightweight and easy to manufacture;

③ convenient installation and transportation.  

Through analysis and comparison of the manufacturability of the two frame types, it is evident that the composite frame offers advantages over the integral frame in terms of both material consumption and production costs. Given the inherently low profit margins in the crusher industry, failure to optimize material usage and manufacturing processes would make it difficult to compete with international counterparts. Therefore, improving frame manufacturing techniques is not only essential but also a practical approach to enhancing competitiveness.