Simulation experiment device for frictional wear behavior of surface of artificial hip joint sample

Abstract

The simulation experiment device for the frictional wear behavior of the surface of the artificial hip joint sample comprises a rack, a hydraulic loading mechanism, a hip joint simulation opposite-grinding pair mechanism, a composite motion mechanism, a lubricating liquid adding mechanism and an abrasive dust adding mechanism, and the simplification of the opposite-grinding pair structure and the simulation of an opposite-grinding track are both considered; a lubricating liquid adding mechanism and an abrasive dust adding mechanism are introduced in combination with actual conditions, artificial hip joint friction wear simulation under different lubricating conditions and abrasive dust forming conditions can be better simulated, and the artificial hip joint friction wear simulation device is more suitable for artificial joint material performance evaluation and selection under laboratory conditions.

Description

Technical Field

[0001] The present invention belongs to artificial joint testing equipment, and particularly relates to a simulation experimental device for the surface friction and wear behavior of artificial hip joint specimens. Background Art

[0002] Inside the human body, the joints connecting bones are the core parts of human movement and play an important role in movements such as moving, rotating, flexing, extending, adducting, and abducting. In recent years, with people's pursuit of a higher quality of life, artificial joint replacement surgery has gradually become a common surgical operation.

[0003] For artificial hip joints, it includes artificial femoral replacement and total hip replacement. Total hip replacement is to implant an artificial hip joint including an acetabular cup, a liner, a ball head, and a femoral stem into the human body to replace the diseased human hip joint. However, a large number of experimental accumulations and verifications are required before applying artificial joints in the human body. Therefore, studying the friction and wear experiments of artificial hip joints has become an aspect of scientific research. In the friction of the hip joint, irregular sliding will occur between the contact surfaces, and the form of the friction pair is surface-to-surface contact. A large number of wear particles, i.e., wear debris, will inevitably be generated during the friction and wear process, gradually leading to bone deterioration and even implant failure. It can be seen that it is very necessary and important to study the friction and wear laws of artificial hip joints and the influence of factors such as friction pair materials, lubricating fluids, and wear debris during the friction and wear process, which puts corresponding requirements on the corresponding experimental simulation devices.

[0004] However, the current research experimental devices in the laboratory have two trends. On the one hand, the focus of the experimental device is mainly on fully simulating the working conditions of actual joints, which requires custom processing of artificial hip joint specimens with specific joint shapes. For the processing and forming of specimens with different materials or surface modifications, as well as the subsequent wear surface analysis, the difficulty and cost are very high. On the other hand, existing standard friction and wear testing machines are directly used for experiments. Currently, the commonly used friction and wear testing machines in the laboratory are friction and wear testing machines mainly based on sliding contact. Ball specimens, plate specimens, and cylindrical specimens are all more easily processed and obtained, which is conducive to the development and analysis of experiments. However, their friction and wear trajectories are relatively simple, the lubrication is quite different from the actual working conditions of joints in the human body, and the influence of wear debris is rarely considered. Therefore, a suitable experimental device for artificial joint materials and research under laboratory conditions is still lacking.

[0005] Based on the influence of the actual body fluid lubrication and wear debris working conditions of joints, developing a simulation experimental device for the surface friction and wear behavior of artificial hip joint specimens with simple specimen processing, which can better simulate the joint movement trajectory and can simulate the body fluid lubrication and wear debris working conditions, has very important social value and significance. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a simulation experimental device for the surface friction and wear behavior of artificial hip joint specimens. The structure of the counter specimen is relatively simple, which can complete the simulation of the friction and wear of artificial joints, and can realize the addition of lubricating fluid, the addition of external wear debris and the collection of generated wear debris.

[0007] To achieve the above object, the main technical solution adopted by the simulation experimental device for the surface friction and wear behavior of artificial hip joint specimens of the present invention is as follows: It includes a frame, a hydraulic loading mechanism, a hip joint simulation counter pair mechanism, a compound motion mechanism, a lubricating fluid addition mechanism, and a wear debris addition mechanism. The upper surface of the frame is loaded with the hydraulic loading mechanism; the compound motion mechanism is connected below the hydraulic loading mechanism; a hip joint simulation counter pair mechanism for conducting counter grinding experiments is provided between the hydraulic loading mechanism and the compound motion mechanism; the lubricating fluid addition mechanism and the wear debris addition mechanism are respectively connected to the side wall of the frame; the hip joint simulation counter pair mechanism includes a ball head simulation specimen and an acetabulum simulation specimen.

[0008] The simulation experimental device for the surface friction and wear behavior of artificial hip joint specimens provided by the present invention also adopts the following subsidiary technical solutions: The hydraulic loading mechanism includes a hydraulic cylinder body, a piston, a piston rod, a guide sleeve, and an elongation support. The hydraulic cylinder body is vertically arranged, one end of the piston rod is connected to the piston, and the other end passes through the lower cover of the hydraulic cylinder and is connected to the elongation support through the guide sleeve.

[0009] The compound motion mechanism includes a four-bar mechanism and a power rotation mechanism. The four-bar mechanism includes a crank-rocker mechanism, a driving motor, and a connecting rod base. The driving motor is connected to the connecting rod base, and the crank-rocker mechanism is installed on the connecting rod base; the power rotation mechanism includes a rotation driving motor, a main transmission shaft, a motor connecting sleeve, and a coupling. The rotation driving motor is fixed on the frame assembly through the motor connecting sleeve, the rotation driving motor is connected to the main transmission shaft through the coupling, and the main transmission shaft is connected to the connecting rod base; the driving motor is used to drive the movement of the crank-rocker mechanism; the power rotation mechanism can drive the connecting rod base to rotate, thereby driving the crank-rocker mechanism to rotate on the horizontal plane, and the crank-rocker mechanism realizes the compound of the reciprocating rotation in the vertical plane and the rotational movement in the horizontal plane.

[0010] The hip joint simulation counter pair mechanism includes an upper counter grinding mechanism and a lower counter grinding mechanism. The upper counter grinding mechanism includes a ball head simulation specimen and a specimen connecting stud; the lower counter grinding mechanism includes an acetabulum simulation specimen, a specimen fixture, a specimen connecting bolt, and a fixing pin.

[0011] The ball head simulation specimen is a spherical specimen; when the hip joint simulation counter pair mechanism is installed, the ball head simulation specimen is fixedly connected to the bottom of the elongation support of the hydraulic loading mechanism through the specimen connecting stud.

[0012] The acetabulum simulation specimen is a square flat specimen with bolt holes at four corners for bolt connection between the acetabulum simulation specimen and the specimen fixture; the acetabulum simulation specimen is bolt-connected to the specimen fixture through specimen connection bolts, and the specimen fixture is installed on the rocker of the crank-rocker mechanism through fixing pins.

[0013] The joint head simulation specimen is located above the acetabulum simulation specimen. Since the acetabulum simulation specimen is a square flat specimen, it can effectively hold up the lubricating fluid, prevent the rapid loss of the lubricating fluid, and make the lubricating fluid evenly applied.

[0014] After the composite motion mechanism is started, it can drive the specimen fixture to achieve irregular spatial motion; the joint head simulation specimen is pressed on the upper plane of the acetabulum simulation specimen through the loading of the hydraulic device, and the composite motion mechanism drives the acetabulum simulation specimen to perform friction along an irregular path on the joint head simulation specimen.

[0015] The lubricating fluid adding mechanism includes a lubricating fluid storage chamber, guide balls, guide grooves, and an inlet spray head; the inlet spray head is located at the front end of the lubricating fluid adding mechanism. After the lubricating fluid is added to the lubricating fluid storage chamber, the guide balls guide the lubricating fluid into the guide grooves.

[0016] The lubricating fluid drips onto the surfaces of the joint head simulation specimen and the acetabulum simulation specimen after flowing out of the inlet spray head; The wear debris adding mechanism includes a wear debris generation chamber, a wear debris grading and processing chamber, a wear debris storage chamber, and a wear debris delivery head; the wear debris generation chamber, the wear debris grading and processing chamber, the wear debris storage chamber, and the wear debris delivery head are connected in sequence; the wear debris generation chamber includes a friction execution component and multiple groups of friction pairs, and the materials of the friction pairs are the same as those of the counter-grinding pairs in the hip joint simulation counter-grinding pair mechanism; the wear debris grading and processing chamber includes a wear debris collection pool, an air drying device, and multiple-stage grading sieves. The wear debris collection pool collects wear debris using anhydrous ethanol, the air drying device dries the wear debris using non-oxidizing gas, and the multiple-stage grading sieves use mechanical vibration to achieve wear debris grading and then store the wear debris in the wear debris storage chamber; the wear debris is transported from the wear debris delivery head to the surfaces of the joint head simulation specimen and the acetabulum simulation specimen through a pipeline.

[0017] The wear debris adding mechanism can be controlled to work or not. According to the experimental conditions, when external wear debris needs to be introduced in the experiment, the wear debris adding mechanism works, and when external wear debris does not need to be introduced in the experiment, the wear debris adding mechanism does not work.

[0018] The friction execution component and multiple groups of friction pairs can generate wear debris consistent with that generated in the hip joint simulation counter-grinding pair mechanism, and the speed of wear debris generation in the friction execution component and multiple groups of friction pairs is faster than that in the hip joint simulation counter-grinding pair mechanism to achieve the purpose of artificially adding wear debris.

[0019] The simulation experimental device for the surface friction and wear behavior of the artificial hip joint sample also includes a wear debris collection and separation pool, which is used to collect the wear debris and lubricating fluid after the grinding experiment and separate the mixture of the wear debris and lubricating fluid.

[0020] The experimental device for simulating friction and wear behavior of the surface of an artificial hip joint specimen provided by the present invention has the following advantages compared with the prior art: First, the present invention combines simplified grinding pair structure with simulated grinding trajectory, making it more suitable for evaluating and selecting artificial joint material properties under laboratory conditions. By incorporating structural designs such as a crank-rocker mechanism and a mechanical gripper, it enables simplified specimen processing, better simulation of the artificial joint grinding trajectory, and the simultaneous or separate addition of lubricant and wear debris during grinding pair testing. This makes the simulation of artificial joint working conditions closer to actual conditions, while significantly reducing the difficulty and cost of processing and subsequent analysis.

[0021] Secondly, the present invention enriches the contact forms of the grinding pair through the design of the motion structure. The crank rocker mechanism and the rotation mechanism are introduced to realize compound motion. When the acetabulum simulation specimen is a ball specimen and a plate specimen, the grinding pair is not only in single point-to-surface contact, but also realizes random point-to-surface contact at different times through compound motion, indirectly realizing surface-to-surface contact. This can make the lower hemisphere of the ball specimen and the flat plate specimen produce better friction. The purpose is to achieve the simulated joint pair grinding experiment as close as possible to the friction and wear form of the human hip joint when the appearance shape of the grinding material is limited.

[0022] Third, the present invention utilizes a lubricating mechanism to control different lubrication conditions during the friction process. The lubricant addition mechanism, combined with a guide mechanism and a controllable nozzle design, simulates the human body fluid environment. When the grinding experiment requires a different body fluid environment, different lubricants can be used to conduct the experiment under different conditions. Furthermore, when the lubrication condition changes from full lubrication to boundary lubrication or even dry friction, real-time control can be achieved.

[0023] Fourth, the present invention achieves simultaneous generation and on-demand addition of wear debris through the design of a wear debris addition mechanism. This mechanism allows for the direct, pre- or simultaneous introduction of external wear debris made of the same material as the artificial joint during the grinding of the artificial joint against the grinding pair. This graded design, which introduces wear debris of varying sizes and types, better simulates the effects of wear debris on human joints under varying conditions, providing a direct reference for the design and selection of artificial joints. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention Figure 2 It is a structural schematic diagram of a four-bar mechanism Figure 3 It is a structural schematic diagram of the hip joint counter-grinding pair mechanism Figure 4 It is a structural schematic diagram of the specimen fixture Figure 5 It is a structural schematic diagram of the lubricating fluid adding mechanism Figure 6 It is a structural schematic diagram of the wear debris adding mechanism Figure 7 It is a structural schematic diagram of the wear debris generation chamber Figure 8 It is a structural schematic diagram of the wear debris grading and treatment chamber Figure 9 It is a structural schematic diagram of the wear debris conveying device Specific implementation manners

[0025] Refer to Figure 1 , a simulation experiment device for the surface friction and wear behavior of an artificial hip joint specimen, including a frame, a hydraulic loading mechanism 1, a compound motion mechanism 2, a hip joint simulation counter-grinding pair mechanism 3, a lubricating fluid adding mechanism 4, and a wear debris adding mechanism 5. The upper surface of the frame is loaded with the hydraulic loading mechanism 1; the compound motion mechanism 2 is connected below the hydraulic loading mechanism 1; a hip joint simulation counter-grinding pair mechanism 3 for carrying out a counter-grinding experiment is provided between the hydraulic loading mechanism 1 and the compound motion mechanism 2; the lubricating fluid adding mechanism 4 and the wear debris adding mechanism 5 are respectively connected to the side wall of the frame; the hip joint simulation counter-grinding pair mechanism 3 includes a joint head simulation specimen and an acetabulum simulation specimen

[0026] The hydraulic loading mechanism 1 includes a hydraulic cylinder body 11, a piston 12, a piston rod 13, a guide sleeve 14, and an extension support 15. The hydraulic cylinder body 11 is vertically arranged. One end of the piston rod 13 is connected to the piston 12, and the other end passes through the lower cover of the hydraulic cylinder and is connected to the extension support 15 through the guide sleeve 14. The extension support 15 is connected to the joint head specimen in the hip joint simulation counter-grinding pair mechanism 3. The piston 12 and the piston rod 13 can adjust the length that the extension support 15 needs to extend. The hydraulic loading mechanism 1 can provide the pressure required in the friction and wear experiment, and the required pressure size is controlled by controlling the hydraulic loading mechanism 1

[0027] Refer to Figure 2, the composite motion mechanism 2 includes a four-bar mechanism 21 and a power rotation mechanism 22. The four-bar mechanism 21 includes a crank-rocker mechanism 211, a driving motor 212, and a connecting rod base 213. The driving motor 212 is connected to the connecting rod base 213, and the crank-rocker mechanism 211 is installed on the connecting rod base 213. The power rotation mechanism 22 includes a rotation driving motor 221, a main transmission shaft 222, a motor connection sleeve 223, and a coupling 224. The rotation driving motor 221 is fixed to the frame through the motor connection sleeve 223. The rotation driving motor 221 is connected to the main transmission shaft 222 through the coupling 224, and the main transmission shaft 222 is connected to the connecting rod base 213. The driving motor 212 is used to drive the motion of the crank-rocker mechanism 211, and the motion realized by the crank-rocker mechanism 211 is a reciprocating rotary motion in the vertical plane. The power rotation mechanism 22 can drive the connecting rod base 213 to rotate, thereby driving the crank-rocker mechanism 211 to rotate in the horizontal plane. The crank-rocker mechanism 211 realizes the compound of the reciprocating rotary motion in the vertical plane and the rotary motion in the horizontal plane.

[0028] See Figure 3 , the hip joint simulation counter-grinding pair mechanism 3 includes an upper counter-grinding mechanism 31 and a lower counter-grinding mechanism 32. The upper counter-grinding mechanism 31 includes a joint head simulation specimen 311 and a specimen connecting stud 312. The lower counter-grinding mechanism 32 includes an acetabulum simulation specimen 321, a specimen clamp 322, a specimen connecting bolt 323, and a fixing pin 324.

[0029] The joint head simulation specimen 311 is a spherical specimen. When the hip joint simulation counter-grinding pair mechanism 3 is installed, the joint head simulation specimen 311 is fixedly connected to the bottom of the extension support 15 of the hydraulic loading mechanism 1 through the specimen connecting stud 312. The acetabulum simulation specimen 321 is a square flat specimen, and there are bolt holes at four corners for bolt connection between the acetabulum simulation specimen 321 and the specimen clamp 322. The acetabulum simulation specimen 321 is tightly bolted to the specimen clamp 322 through the specimen connecting bolt 323. When a large clamping force is required, the force of tightening the bolt can be adjusted. The specimen clamp 322 is installed on the rocker of the crank-rocker mechanism 211 through the fixing pin 324. The composite motion mechanism 2 can drive the lower counter-grinding mechanism 32 to perform a composite motion with a random path, so that the acetabulum simulation specimen 321 and the joint head simulation specimen 311 are rubbed against each other.

[0030] The joint head simulation specimen 311 is located above the acetabulum simulation specimen 321. Since the acetabulum simulation specimen 321 is a square flat specimen, the lubricating liquid can be effectively lifted to prevent the lubricating liquid from being lost too quickly, and the lubricating liquid can be evenly applied. The acetabulum simulation specimen 321 always has a certain angle with the joint head simulation specimen 311 during the movement, which can ensure that the lubricating liquid and wear chips fall in time without accumulation, thereby reducing the interference of wear chip accumulation factors during the surface friction and wear experiment of the artificial hip joint specimen.

[0031] Reference Figure 4 The sample clamp 322 is a clamp hand with adjustable clamping width. The sample clamp 322 includes a slide bar 3221, a sleeve 3222, a rotating nut 3223, a chuck 3224, and a fixing frame 3225. The sleeve 3222 and the slide bar 3221 are connected by an axial hole clearance fit, and relative sliding can occur between the two. The chuck 3224 and the fixing frame 3225 are connected by loose bolts. The distance between the three chucks 3224 can be adjusted by rotating the nut 3223, so that the clamp can clamp the acetabulum simulation sample 321 within a certain range.

[0032] Reference Figure 5 The lubricating liquid adding mechanism 4 includes a lubricating liquid storage chamber 41, a guide ball 42, a guide groove 43, and an introduction nozzle 44; the introduction nozzle 44 is located at the front end of the lubricating liquid adding mechanism 4. After the lubricating liquid is added to the lubricating liquid storage chamber 41, the guide ball 42 guides the lubricating liquid into the guide nozzle 44 through the guide groove 43. The lubricating liquid storage chamber 41 includes a dust cap and a filter. The filter filters the lubricating liquid before it is discharged. The dust cap can prevent impurities in the air from mixing into the lubricating liquid during the experiment, ensuring a high degree of cleanliness of the lubricating liquid. The guide ball 42 can ensure that when the concentration of the lubricating liquid used is high, the lubricating liquid can be quickly guided from the guide groove 43 to the introduction nozzle 44. The introduction nozzle 44 is a nozzle with a valve that can control the dripping and stopping of the lubricating liquid.

[0033] Reference Figure 6 The wear-chip adding mechanism 5 includes a wear-chip generating chamber 51, a wear-chip grading processing chamber 52, a wear-chip storage chamber 53, and a wear-chip conveying device 54; the wear-chip generating chamber 51, the wear-chip grading processing chamber 52, the wear-chip storage chamber 53, and the wear-chip conveying device 54 are connected in sequence. The wear-chip adding mechanism 5 can realize operation and interruption. When the experiment requires the introduction of external wear chips, the wear-chip adding mechanism 5 is turned on, and the wear chips are rapidly generated simultaneously and directly conveyed to the surface of the grinding pair sample. This process uses a grinding pair of the same material to realize on-site generation of wear chips and quickly realizes classification and screening, which can better simulate the actual working conditions affected by different wear chips. When the experiment does not need to introduce external wear chips, the wear-chip adding mechanism 5 stops working.

[0034] ReferenceFigure 7 The chip generation chamber 51 includes a friction execution component 511 and multiple sets of friction pairs 512. The friction execution component 511 can drive the multiple sets of friction pairs 512 to perform friction. No lubricant is added during the friction of the multiple sets of friction pairs 512. Severe wear occurs during the friction process, generating a large amount of chips. The materials of the multiple sets of friction pairs 512 are the same as those of the counter friction pairs in the hip joint simulation counter friction pair mechanism 3. After the chips are generated, they fall into the chip grading and processing chamber 52 for separation.

[0035] Refer to Figure 8 The chip grading and processing chamber 52 includes a chip collection pool 521, an air drying device 522, and a multi-stage grading screen 523. The chip collection pool 521 collects chips using anhydrous ethanol, and the anhydrous ethanol is a liquid for cleaning the chips. The air drying device 522 dries the chips using a non-oxidizing gas. The multi-stage grading screen 523 uses mechanical vibration to achieve chip grading and then enters the chip storage chamber 53 for storage.

[0036] Refer to Figure 9 The chip conveying device 54 includes a conveying pipeline 541, a conical fan blade 542, a small motor 543, and a chip outlet 544. The inside of the conveying pipeline 541 is a conical fan blade 542. The small motor 543 can drive the conical fan blade 542 to rotate, and the chips are transported to the chip outlet 544 through rotation. The rotation of the conical fan blade 542 drives the chips to be transported layer by layer, which can effectively prevent the blocking of the conveying pipeline 541 caused by excessive chips transported at one time. The chip outlet 544 is circular to ensure the smooth discharge of the chips.

[0037] The specific experimental process of the simulation experimental device for the surface friction and wear behavior of an artificial hip joint specimen is as follows. First, connect the articular head specimen 311 in the hip joint simulation counter-grinding pair mechanism 3 to the elongation support 15 in the hydraulic loading mechanism 1 by using the specimen connection stud 312. Adjust the specimen clamp 322 in the lower counter-grinding mechanism 32 so that the specimen clamp 322 can clamp the acetabulum simulation specimen 321. Use the specimen connection bolt 323 to bolt-connect the acetabulum simulation specimen 321 to the specimen clamp 322. Install the connected specimen clamp 322 on the rocker of the crank-rocker mechanism 211 by using the fixing pin 324. Adjust the piston 12 and the piston rod 13. When the articular head specimen 311 contacts the acetabulum simulation specimen 321, the elongation support 15 reaches the required elongation length. After the articular head specimen 311 and the acetabulum simulation specimen 321 are installed, close the valve of the introduction nozzle 44 in the lubricant addition mechanism 4. Add three-quarters of the lubricant to the lubricant storage chamber 41, and let it stand for 5 minutes to filter the lubricant through the filter screen. Start the driving motor 212 and the rotary driving motor 221. Driven by the four-bar mechanism 21 and the power rotary mechanism 22, the acetabulum simulation specimen 321 clamped by the specimen clamp 322 starts to friction with the articular head specimen 311 in the upper counter-grinding mechanism 31. At this time, open the valve of the introduction nozzle 44 to let the lubricant drip onto the surfaces of the articular head simulation specimen and the acetabulum simulation specimen, and bring it into the counter-grinding contact surface of the friction pair during the friction and wear process.

[0038] When external wear debris needs to be introduced in this experiment, the wear debris addition mechanism 5 needs to work. First, install multiple groups of friction pairs 512 and the friction execution component 511. Start the friction execution component 511 in the wear debris generation chamber 51 to make the multiple groups of friction pairs 512 friction to generate the required wear debris. The wear debris falls into the wear debris collection pool 521 in the wear debris classification and treatment chamber 52. After the wear debris is mixed and cleaned with anhydrous ethanol, the air-drying device 522 uses non-oxidizing gas to dry the wear debris and then blows the wear debris onto the multi-stage grading sieve 523. Use mechanical vibration to grade the wear debris. Based on different simulated working conditions, the grading of nano-scale wear debris, 1-10 micron wear debris, 10-50 micron wear debris, and 50-100 micron wear debris is realized. The wear debris that can pass through the multi-stage grading sieve 523 falls into the wear debris storage chamber 53 for storage. When the wear debris working condition needs to be simulated in the experiment, after determining the corresponding wear debris particle size, start the small motor 543 in the wear debris conveying device 54. Driven by the rotation of the conical fan blade 542, the generated wear debris is transported step by step to the debris outlet 544. The wear debris falls from the debris outlet 544 onto the surfaces of the articular head simulation specimen and the acetabulum simulation specimen of the hip joint simulation counter-grinding pair mechanism 3, and is brought into the counter-grinding contact surface of the friction pair during the friction and wear process.

[0039] Under the conditions where the above lubrication conditions and wear debris conditions exist alone or simultaneously, the artificial joint counterpair undergoes a friction and wear simulation experiment under parameters such as a set load and speed for a corresponding period of time. After the entire counterpair experiment, the mixture of wear debris and lubricant will fall into the wear debris collection and separation tank, and the lubricant and wear debris are further separated. The separated wear debris can be used for the next analysis and comparison.

[0040] A simulation experimental device for the surface friction and wear behavior of an artificial hip joint sample of the present invention takes into account the simplification of the counterpair structure and the simulation of the counterpair trajectory. Through the design of the motion mechanism, the diversification of the contact form of the counterpair is realized. By introducing a lubricant addition mechanism and a wear debris addition mechanism in combination with the actual situation, it can better simulate the friction and wear of the artificial hip joint under different lubrication conditions and wear debris formation conditions, and is more suitable for the evaluation and selection of the performance of artificial joint materials under laboratory conditions.

Claims

1. Simulation experimental device for surface friction and wear behavior of artificial hip joint specimens, characterized in that: It includes a frame, a hydraulic loading mechanism, a hip joint simulation counter-grinding pair mechanism, a compound motion mechanism, a lubricating fluid adding mechanism, and a wear debris adding mechanism. The upper surface of the frame is loaded with the hydraulic loading mechanism. The compound motion mechanism is connected below the hydraulic loading mechanism. A hip joint simulation counter-grinding pair mechanism for conducting counter-grinding experiments is provided between the hydraulic loading mechanism and the compound motion mechanism. The lubricating fluid adding mechanism and the wear debris adding mechanism are respectively connected to the side wall of the frame. The hip joint simulation counter-grinding pair mechanism includes a femoral head simulation specimen and an acetabulum simulation specimen. The lubricating fluid adding mechanism and the wear debris adding mechanism can respectively transport the lubricating fluid and the wear debris to the surfaces of the femoral head simulation specimen and the acetabulum simulation specimen to simulate the friction and wear under the corresponding working conditions.

2. The simulation experimental device for the surface friction and wear behavior of the artificial hip joint specimen according to claim 1, wherein: The wear debris adding mechanism includes a wear debris generation chamber, a wear debris grading and treatment chamber, a wear debris storage chamber, and a wear debris conveying device. The wear debris generation chamber, the wear debris grading and treatment chamber, the wear debris storage chamber, and the wear debris conveying device are connected in sequence.

3. The simulation experimental device for the surface friction and wear behavior of the artificial hip joint specimen according to claim 1, wherein: The compound motion mechanism includes a four-bar mechanism and a power rotation mechanism. A crank-rocker mechanism is used in the four-bar mechanism. The power rotation mechanism can make the crank-rocker mechanism perform horizontal rotation to realize the compound of the reciprocating motion in the vertical plane and the rotational motion in the horizontal plane of the crank-rocker mechanism.

4. The simulation experimental device for the surface friction and wear behavior of the artificial hip joint specimen according to claim 1, wherein: The hip joint simulation counter-grinding pair mechanism includes an upper counter-grinding mechanism and a lower counter-grinding mechanism. The upper counter-grinding mechanism includes a femoral head simulation specimen. The lower counter-grinding mechanism includes an acetabulum simulation specimen and a specimen fixture.

5. The simulation experimental device for the surface friction and wear behavior of the artificial hip joint specimen according to claim 4, characterized in that: The femoral head simulation specimen is a spherical specimen. When the hip joint simulation counter-grinding pair mechanism is installed, the femoral head simulation specimen is fixedly connected to the bottom of the extension support of the hydraulic loading mechanism through a specimen connection stud.

6. The simulation experimental device for the surface friction and wear behavior of the artificial hip joint specimen according to claim 4, wherein: The acetabulum simulation specimen is a square flat specimen. The acetabulum simulation specimen is bolted to the specimen fixture through a specimen connection bolt. The specimen fixture is installed on the rocker of the crank-rocker mechanism through a fixing pin.

7. The simulation experimental device for the surface friction and wear behavior of the artificial hip joint specimen according to claim 4, wherein: After the compound motion mechanism is started, it can drive the specimen fixture to realize irregular spatial motion. The femoral head simulation specimen is pressed on the upper plane of the acetabulum simulation specimen through the loading of the hydraulic device. The compound motion mechanism drives the acetabulum simulation specimen to conduct friction on the femoral head simulation specimen along an irregular path.

8. The simulation experiment device for the surface friction and wear behavior of an artificial hip joint specimen according to claim 1, characterized in that: The lubricating fluid adding mechanism includes a lubricating fluid storage chamber, a guiding ball, a guiding groove, and an introducing nozzle. The introducing nozzle is located at the front end of the lubricating fluid adding mechanism. After the lubricating fluid is added to the lubricating fluid storage chamber, the guiding ball guides the lubricating fluid through the guiding groove into the guiding nozzle.

9. The simulation experimental device for the surface friction and wear behavior of the artificial hip joint specimen according to claim 2, characterized in that: The wear debris generation chamber includes a friction execution component and multiple groups of friction pairs. The material of the friction pairs is the same as that of the counter-grinding pairs in the hip joint simulation counter-grinding pair mechanism.

10. The simulation experimental device for the surface friction and wear behavior of the artificial hip joint specimen according to claim 2, wherein: The wear debris grading and treatment chamber includes a wear debris collection pool, an air-drying device, and a multi-stage grading sieve. The wear debris collection pool collects the wear debris with absolute ethanol. The air-drying device dries the wear debris with non-oxidizing gas. The multi-stage grading sieve realizes the grading of the wear debris by mechanical vibration and then stores it in the wear debris storage chamber. The wear debris is transported to the surfaces of the femoral head simulation specimen and the acetabulum simulation specimen through the wear debris conveying device.

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