A piston rod structure
Patent Information
- Application Number
- CN202522328815.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-03
- Publication Date
- 2026-09-08
- Estimated Expiration
- 2035-11-03
AI Technical Summary
[0002]活塞杆作为泥浆泵的核心部件，其工作环境极端恶劣，长期承受高浓度磨蚀性颗粒的冲刷、腐蚀性介质的侵蚀以及交变冲击载荷，现有技术中的泥浆泵活塞杆多采用整体式结构，其光杆表面大多经过镀硬铬等传统处理，在强磨蚀工况下也极易被快速拉伤，形成难以修复的沟槽，导致与之配合的密封件急速失效，引发泥浆泄漏，不仅污染环境更影响生产安全，一旦杆体损伤，传统解决方案是停机后拆卸泵头、活塞等大量部件，对活塞杆进行整体修复或更换，此过程费时费力，维护成本高昂，且严重制约设备作业率
1、本实用新型维护成本降低的同时效率得到提升，将易损的外表面功能与核心承力结构分离，当与泥浆直接摩擦的外套管磨损或拉伤时，无需如传统方式般拆卸活塞和整个杆体进行整体更换或复杂修复，仅需松开连接螺栓，即可将受损外套管卸下更换新件，将原本耗时数小时的维护工作缩短至几十分钟，极大减少了设备停机时间，维护成本显著降低；
Smart Images
Figure CN224729741U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of mud pumps, and in particular relates to a piston rod structure. Background Technology
[0002] As the core component of a mud pump, the piston rod operates in an extremely harsh environment, enduring long-term scouring by high concentrations of abrasive particles, erosion by corrosive media, and alternating impact loads. Existing mud pump piston rods mostly employ an integral structure, with their smooth surfaces often treated with traditional methods such as hard chrome plating. Under intense abrasive conditions, these rods are easily and rapidly scratched, forming grooves that are difficult to repair. This leads to the rapid failure of the mating seals, causing mud leaks that not only pollute the environment but also affect production safety. Once the rod is damaged, the traditional solution is to shut down the pump and disassemble numerous components such as the pump head and piston for overall repair or replacement. This process is time-consuming, labor-intensive, and costly, severely limiting equipment operating rates. Utility Model Content
[0003] The purpose of this invention is to provide a piston rod structure to solve the problems existing in the prior art.
[0004] To achieve the above objectives, the present invention adopts a piston rod structure, including an inner central column, one end of which is connected to a piston. A reinforcing locking part is provided between the inner central column and the piston. An outer clamping tube is provided above the reinforcing locking part. An inner clamping tube is provided on the inner circumference of the outer clamping tube. A concave hexagon is provided at the end of the inner central column away from the piston. A detachable outer sleeve is provided above the inner central column. An insertion tube is provided at one end of the outer sleeve. Through holes are provided on the insertion tube, the outer clamping tube, the inner clamping tube, and the inner central column. A screw passes through the through hole and a bolt is installed on the screw for fixation. A convex hexagon is provided on the inner side of the end of the outer sleeve away from the insertion tube. The convex hexagon fits into the concave hexagon. An external thread for connecting a load is provided on the outer circumference of the end of the outer sleeve away from the insertion tube.
[0005] Preferably, the reinforcing locking part includes an inner groove, an inner shell tube, a first mounting hole, an outer cover tube, a second mounting hole, and a protruding tube. The inner groove is formed on the piston and has threads on its circumference. The inner shell tube is located on the circumference above the inner groove, and its diameter is larger than that of the inner groove. The first mounting hole is formed through the circumference of the inner shell tube. The outer cover tube is located on the end of the inner central column away from the concave hexagon, and its diameter is larger than that of the inner shell tube. The second mounting hole is formed on the circumference of the outer cover tube. The protruding tube is located below the outer cover tube and has threads on its outer circumference. The protruding tube is adapted to and connected to the inner groove. The outer cover tube covers the outer circumference of the inner shell tube. Bolts pass through the first mounting hole and the second mounting hole for locking and fixing.
[0006] Preferably, a sealing ring is provided between the outer cover tube and the inner shell tube.
[0007] Preferably, the outer sleeve is made of wear-resistant alloy steel, and its outer surface is subjected to nitriding or hard chrome plating to form a surface hardening layer.
[0008] Preferably, both the inner and outer clamping tubes are made of corrosion-resistant stainless steel.
[0009] Preferably, the inner walls of the through holes are precision reamed, with a surface roughness Ra value of less than 1.6 μm, and there is a transition fit between the through holes and the screw.
[0010] Compared with the prior art, the advantages and positive effects of this utility model are as follows: 1. This utility model reduces maintenance costs while improving efficiency. It separates the vulnerable outer surface function from the core load-bearing structure. When the outer sleeve, which rubs directly against the mud, is worn or scratched, it is not necessary to disassemble the piston and the entire rod for overall replacement or complex repair as in the traditional way. Simply loosen the connecting bolts to remove the damaged outer sleeve and replace it with a new one. This reduces the maintenance work that originally took several hours to tens of minutes, greatly reducing equipment downtime and significantly reducing maintenance costs. 2. The design adopts multiple reliable connection mechanisms. The insertion tube and clamp tube near the piston end are tightly fixed to the inner central column through the through screw to form a stable locking support. The concave hexagonal and convex hexagonal interlocking structure at the other end ensures the effective transmission of working torque and prevents relative rotation. This design not only ensures the rigidity of the overall structure, but also achieves precise alignment and reliable connection between modules. 3. The inner central column of this structure can focus on ensuring strength and toughness, while the outer sleeve, which is a sacrificial component, can be independently selected from wear-resistant alloy steel materials that are more wear-resistant and corrosion-resistant. The intact sleeve can be quickly replaced according to the damage situation, which improves the adaptability and economy of the product. Attached Figure Description
[0011] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0012] Figure 1 This is a schematic diagram of the overall structure of a piston rod; Figure 2 This is a schematic diagram of the installation structure between the outer sleeve and the inner central column; Figure 3 This is a schematic diagram of the structure of the inner central column; Figure 4 This is a schematic diagram of the outer casing. Figure 5 This is a bottom view of the outer tube.
[0013] In the above figures, 1. Piston, 2. Inner groove, 3. Inner shell tube, 4. Mounting hole one, 5. Outer cover tube, 6. Mounting hole two, 7. Sealing ring, 8. Convex tube, 9. Outer sleeve tube, 10. External thread, 11. Inner center post, 12. Concave hexagon, 13. Outer clamp tube, 14. Inner clamp tube, 15. Through hole, 16. Convex hexagon, 17. Insert tube, 18. Screw, 19. Reinforcing locking part. Detailed Implementation
[0014] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.
[0015] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.
[0016] Example 1, such as Figure 1-5 As shown, the specific design of the aforementioned key components is described below: A piston rod structure includes an inner central column 11, one end of which is connected to a piston 1. A reinforcing locking part 19 is provided between the inner central column 11 and the piston 1. An outer clamping tube 13 is provided above the reinforcing locking part 19. An inner clamping tube 14 is provided on the inner circumference of the outer clamping tube 13. A concave hexagonal shape 12 is provided at the end of the inner central column 11 away from the piston 1. A detachable outer sleeve 9 is provided above the inner central column 11. One end of the sleeve 9 is provided with an insertion tube 17. The insertion tube 17, the outer clamp tube 13, the inner clamp tube 14, and the inner central column 11 are all provided with through holes 15. A screw 18 passes through the through hole 15 and a bolt is installed on the screw 18 for fixing. The inner side of the outer sleeve 9 away from the insertion tube 17 is provided with an outwardly convex hexagon 16, which fits into the inwardly concave hexagon 12. The outer periphery of the outer sleeve 9 away from the insertion tube 17 is provided with an external thread 10 for connecting the load.
[0017] The piston rod achieves reliable force transmission and a stable, sealed structure through multiple mechanical connections and fittings. In terms of connection, the thrust at the piston 1 end integrates the inner central column 11, inner clamp tube 14, and outer clamp tube 13 into one unit through the reinforcing locking part 19, and applies pre-tightening force using the threaded rod 18 and bolts that pass through the three, forming the first rigid connection node. At the same time, the insertion tube 17 at one end of the outer sleeve tube 9 is inserted into this combined structure and locked together by the threaded rod 18, forming the second connection node. The convex hexagon 16 at its other end and the concave hexagon 12 of the inner central column 11 are precisely fitted together, forming a key anti-torsion connection, ensuring effective torque transmission. The reinforcing locking part 19 itself achieves anti-loosening and sealing of the connection between the piston 1 and the rod body through a threaded connection. The tight fitting and pressing of the inner shell tube 3 and the outer cover tube 5 further enhances the overall rigidity and improves the consistency of the sealing interface from a structural perspective. This design greatly enhances the connection reliability and fatigue resistance of the structure under complex alternating loads, effectively preventing loosening. Moreover, the modular design allows the outer sleeve 9, which is a vulnerable part, to be replaced independently and quickly, solving the problem of traditional integral rods being scrapped due to local wear. Maintenance costs and downtime are significantly reduced. The design of the reinforced locking part 19 and the continuous contact interface formed by the precise cooperation of various components together construct an effective sealing barrier, significantly improving the sealing performance and service life between the piston rod and piston 1.
[0018] The reinforcing locking part 19 includes an inner groove 2, an inner shell tube 3, a first mounting hole 4, an outer cover tube 5, a second mounting hole 6, and a protruding tube 8. The inner groove 2 is formed on the piston 1 and has threads on its circumference. The inner shell tube 3 is located on the circumference above the inner groove 2, and its diameter is larger than that of the inner groove 2. The first mounting hole 4 is formed through the circumference of the inner shell tube 3. The outer cover tube 5 is located on the end of the inner central column 11 away from the concave hexagon 12, and its diameter is larger than that of the inner shell tube 3. The second mounting hole 6 is formed on the circumference of the outer cover tube 5. The protruding tube 8 is located below the outer cover tube 5 and has threads on its outer circumference. The protruding tube 8 is adapted to and connected to the inner groove 2. The outer cover tube 5 covers the outer circumference of the inner shell tube 3. Bolts pass through the first mounting hole 4 and the second mounting hole 6 for locking and fixing.
[0019] The reinforced locking part 19 achieves a reliable connection and seal between the piston 1 and the inner central column 11 through the triple action of threaded connection, inner shell tube 3, outer cover tube 5, and bolt locking. First, the axial connection and initial tightening of the foundation are completed by screwing the threads of the convex tube 8 and the inner groove 2, forming the first line of defense for the connection. Subsequently, the outer cover tube 5, with its larger diameter, fits around the outer circumference of the inner shell tube 3, forming precise radial positioning and containment, enhancing the centering and bending resistance of the structure. Finally, the bolt passes through mounting hole 1 4 and mounting hole 2 6 and is tightened, locking and pressing the outer cover tube 5 and the inner shell tube 3 into one unit. This not only eliminates the potential gap of the threaded connection but also applies a strong radial preload, thereby achieving the final reinforcement and sealing of the connection. This design greatly enhances the vibration and impact resistance of the connection point, effectively preventing the risk of the piston 1 and the rod body loosening under alternating loads, and structurally achieves a seal on the metal end face, ensuring the long-term reliability of the seal.
[0020] A sealing ring 7 is provided between the outer cover tube 5 and the inner shell tube 3. The outer sleeve tube 9 is made of wear-resistant alloy steel, and its outer surface is nitrided or hard chrome plated to form a surface hardening layer. The inner clamp tube 14 and the outer clamp tube 13 are both made of corrosion-resistant stainless steel. The inner wall of the through hole 15 is precision reamed, and its surface roughness Ra value is less than 1.6μm. It is also transitionally fitted with the screw 18.
[0021] The sealing ring 7 forms an elastic compression at the interface between the outer cover tube 5 and the inner shell tube 3, constituting a flexible sealing barrier. The through hole 15, precision-reamed to Ra < 1.6 μm, and the screw 18 are fitted with a transition fit, eliminating microscopic gaps between the connecting pairs and achieving extremely high fitting accuracy and contact stiffness. Structurally, this forms a precise metal-to-metal seal and rigid connection. In terms of reinforcement and durability, the wear-resistant alloy steel outer shell tube 9, treated with nitriding or hard chrome plating, serves as the main wear-bearing surface. Its surface hardened layer directly resists abrasive wear. Simultaneously, the corrosion-resistant stainless steel inner clamp tube 14 and outer clamp tube 13 prevent dimensional changes or strength degradation due to corrosion from within the structure. The insertion tube 17 is precisely inserted between the outer clamp tube 13 and the inner clamp tube 14, forming a precision mechanical seal, ensuring the stability of the connection preload and structural integrity under long-term use. This design ensures reliable sealing of the connection points under vibration conditions, and each component can perform optimally under its core operating conditions, together ensuring the piston rod assembly has an ultra-long service life and extremely low maintenance requirements in harsh environments.
[0022] The contents not described in detail in this specification are existing technologies known to those skilled in the art.
[0023] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.
Claims
1. A piston rod structure, characterized in that, The device includes an inner central column, one end of which is connected to a piston. A reinforcing locking part is provided between the inner central column and the piston. An outer clamping tube is provided above the reinforcing locking part. An inner clamping tube is provided on the inner circumference of the outer clamping tube. The end of the inner central column away from the piston has a concave hexagon. A detachable outer sleeve is provided above the inner central column. An insertion tube is provided at one end of the outer sleeve. Through holes are provided on the insertion tube, the outer clamping tube, the inner clamping tube, and the inner central column. A screw passes through the through hole and a bolt is installed on the screw for fixation. A convex hexagon is provided on the inner side of the end of the outer sleeve away from the insertion tube. The convex hexagon fits into the concave hexagon. An external thread for connecting a load is provided on the outer circumference of the end of the outer sleeve away from the insertion tube.
2. The piston rod structure according to claim 1, characterized in that, The reinforcing locking part includes an inner groove, an inner shell tube, a first mounting hole, an outer cover tube, a second mounting hole, and a protruding tube. The inner groove is formed on the piston and has threads on its circumference. The inner shell tube is located on the upper circumference of the inner groove, and its diameter is larger than that of the inner groove. The first mounting hole is formed through the inner shell tube on its circumference. The outer cover tube is located on the end of the inner central column away from the concave hexagon, and its diameter is larger than that of the inner shell tube. The second mounting hole is formed on the circumference of the outer cover tube. The protruding tube is located below the outer cover tube and has threads on its outer circumference. The protruding tube is adapted to and connected to the inner groove. The outer cover tube covers the outer circumference of the inner shell tube. Bolts pass through the first mounting hole and the second mounting hole for locking and fixing.
3. The piston rod structure according to claim 2, characterized in that, A sealing ring is provided between the outer cover tube and the inner shell tube.
4. A piston rod structure according to claim 3, characterized in that, The outer sleeve is made of wear-resistant alloy steel, and its outer surface is nitrided or hard chrome plated to form a surface hardened layer.
5. A piston rod structure according to claim 4, characterized in that, Both the inner and outer clamps are made of corrosion-resistant stainless steel.
6. A piston rod structure according to claim 5, characterized in that, The inner walls of the through holes are all precision reamed, with a surface roughness Ra value of less than 1.6 μm, and there is a transition fit between them and the screw.