Product Introduction of Positioning Disk
The positioning disc is a positioning metal accessory in the related assembly structure of drilling mud pumps. It mainly performs radial positioning, axial limit or installation position correction on adjacent parts through structures such as center holes, positioning outer circles, steps, end faces or installation holes, keeping the relevant components in the specified center position and assembly relationship.
During the operation of the mud pump, there are continuous reciprocating loads, pressure pulsations and mechanical vibrations. If the relevant parts are not accurately positioned, it may cause assembly eccentricity, local eccentric loading, abnormal wear or uneven force distribution at the connection position. The positioning disc, through the positioning reference formed by its processing, provides a stable installation foundation for the matching parts.
The "positioning plates" referred to by different series of mud pumps may vary in installation position and structural form. Some are coaxially positioned through a center hole and an outer circle, while others achieve axial limit through steps or stop mouths. They may also be equipped with installation holes or other mating structures simultaneously. Therefore, the specific dimensions and installation positions cannot be determined merely by the name of the "positioning plate". When purchasing, the model of the mud pump, the original part number and the technical drawings should be checked for verification.
The main function of the positioning disk
1. Radial positioning: Through the center hole, positioning outer circle or stop mouth, it forms a fit with the matching parts to restrict the radial movement of adjacent components and maintain the specified center position.
2. Axial limit: The end face, steps or positioning shoulder of the positioning disc can be used as the axial assembly reference to restrict unnecessary displacement of related parts in the axial direction.
3. Maintain assembly relationship: When multiple parts are combined and installed, the positioning plate can help maintain the center distance, coaxial relationship and end face position between adjacent parts, providing the correct assembly basis for subsequent pressing, locking or sealing structures.
4. Transfer local support loads: In some structures, the positioning discs also bear certain end face support or assembly loads. The specific bearing method should be determined according to the corresponding pump type structure.
The working principle of positioning
The positioning disc usually forms a specified dimensional fit with adjacent parts by using a precisely machined center hole, outer circle, stop mouth, positioning step and end face. After assembly is completed, these positioning surfaces restrict the free movement of the parts in the radial or axial direction, thereby establishing a stable assembly reference.
The positioning effect mainly depends on the positioning diameter, fit clearance, step height, end face condition and the machining accuracy of related components. If the positioning holes or the outer circle of the positioning is worn, even if the fasteners can still be installed normally, it may no longer be possible to ensure the original designed center position.
Therefore, the positioning plate cannot be simply understood as an ordinary pad. For installation positions that need to maintain a coaxial relationship, the dimensions of the center hole, stop mouth and end face are usually more worthy of careful verification than those of ordinary connectors.
Center hole and positioning stop mouth
The center hole is one of the common key structures of positioning discs and may form a fit with shaft, sleeve or other cylindrical positioning parts. When purchasing, it is necessary to confirm the diameter of the center hole and whether there are step holes of different diameters inside.
For structures that use stop positioning, the diameter, height and fit position of the positioning stop should also be confirmed. Even if the outer diameters and thicknesses of two positioning discs are the same, they may not be installed correctly as long as the sizes of the center holes or stop mouths are different.
If the positioning parts are required to maintain a coaxial relationship, the positional accuracy between the center hole, the outer circle and the relevant end faces should also be controlled in accordance with the original drawing requirements. It is not allowed to only check the individual diameter dimensions.
Installation holes and direction requirements
Some positioning discs are provided with bolt holes, screw holes, positioning pin holes or other installation holes. For such structures, in addition to the hole diameter, it is also necessary to confirm the number of holes, hole spacing, distribution circle and hole position direction.
If the positioning disk adopts asymmetric hole positions, offset holes or special step structures, there may be clear direction requirements during installation. It cannot be replaced by expanding the installation holes or forcibly misaligning the installation, otherwise the original positioning relationship may be disrupted.
The difference from wear-resistant discs
Positioning plate: Its main function is to establish an installation reference, perform radial positioning, axial limit or maintain coaxial relationship for the matching parts.
Wear-resistant plate: In the installation system of the mud pump cylinder liner, it usually mainly undertakes the protection and support of the installation surface as well as the coordination of the cylinder liner sealing related structures. It is a part with clear wear-resistant and protective functions.
Both may adopt disc-shaped metal structures, but it cannot be assumed that their functions are the same just because of their similar appearances. When selecting the model, it should be confirmed respectively according to the installation position, center hole, step, sealing cavity and matching parts.
The difference from sealing rings and gland covers
Positioning discs are usually rigid metal positioning components and do not form sealing rings by elastic deformation themselves. If O-rings or other seals are set near the positioning disk, the actual sealing function is mainly accomplished by the corresponding seals.
The positioning disk is also different from the press cover. The main task of the gland is usually to generate or maintain axial clamping force, while the positioning plate places more emphasis on establishing the correct installation position and geometric reference. In some structures, the two may work together, but the functions should not be mixed into one.
Common wear and tear and inspection
When inspecting the positioning disk, special attention should be paid to checking the center hole, positioning outer circle, stop mouth, step, support end face and installation hole.
Common abnormalities include expanded wear of positioning holes, wear of the positioning outer circle, step indentations, end face eccentric wear, wear of installation holes, corrosion, deformation and local cracks.
If the relevant components of the equipment repeatedly wear out, the center position is abnormal after assembly, or there is still a significant radial clearance after fastening, the positioning disc and the positioning surfaces that cooperate with it should be inspected instead of merely increasing the fastening force.
Key points for selection
When purchasing positioning discs for drilling mud pumps, it is recommended to focus on confirming the following information:
1. Brand, series and specific model of mud pump;
2. Specific installation location of the positioning disk and its matching assemblies;
3. Original part number;
4. Outer diameter of the positioning disk;
5. Diameter of the center hole and dimensions of the internal steps;
6. Total thickness;
7. Position the diameter and height of the stop mouth;
8. Axial positioning step size;
9. Number and diameter of installation holes;
10. Center distance of installation holes or distribution circle;
11. Whether positioning pin holes or special hole positions are set;
12. Fit relationship with adjacent parts;
13. Materials, heat treatment and surface requirements;
14. Physical samples or technical drawings.
Installation and Maintenance
Before installation, the center hole of the positioning disk, the positioning outer circle, the stop mouth, the steps and the support end face should be cleaned. Mud, rust, metal shavings and burrs should be removed to avoid foreign objects affecting the positioning accuracy.
When assembling, it should be confirmed that the positioning plate can correctly enter the corresponding stop mouth or positioning position. Do not install parts with mismatched dimensions by knocking, enlarging the installation holes or forcibly tightening.
For positioning discs with installation directions, the front and back sides and the direction of the hole positions should be confirmed according to the original assembly relationship. After installation is completed, it is necessary to check whether adjacent components are correctly fitted. There should be no obvious lifting, skewing or abnormal gaps.
If a sealing ring is installed near the positioning disk at the same time, it is also necessary to check whether the sealing part is correctly inserted into the sealing groove to prevent the sealing part from being pinched or crushed during the assembly of the positioning disk.
Procurement Instructions
Juli Petroleum Drilling and Production Equipment Co., Ltd. provides positioning discs and structural components for drilling mud pumps. The positioning disc is mainly used for radial positioning, axial limit and assembly reference holding of related components. Due to the fact that the specific installation position and structure of the positioning plate may vary among different models of mud pumps, it is recommended to provide the model of the mud pump, installation assembly, outer diameter of the positioning plate, center hole, thickness, positioning stop mouth, installation hole position, original part number, physical samples or technical drawings for matching confirmation when purchasing.