quality Shock Absorber Parts & Shock Absorber Piston factory

The piston rod is the transmission and guiding rod of the shock absorber. When we drive on a bumpy road, the wheels are impacted and the force is first transmitted to the piston of the shock absorber. One end of the piston rod is connected to the piston and the other end to the vehicle body. There is a top rubber on the shock absorber, and the piston rod is connected to the top rubber. Below the top rubber is a spring, and the top rubber is directly connected to the vehicle body, which can smoothly transmit the impact force and guide the piston to move back and forth in the shock absorber cylinder without deviation. When the piston moves, the hydraulic oil in the shock absorber flows through the small holes on the piston to generate damping force to counteract the vibration. The sealing performance of the piston rod directly affects the leakage of the hydraulic oil. If the sealing at the connection between the piston rod and the shock absorber system is not good and the hydraulic oil leaks, there will be no damping force, and the shock absorber will become an empty shell. Driving will feel extremely bumpy and the vehicle body will shake significantly. Therefore, sealing performance is also a key factor for the piston rod. In addition, the piston rod has the functions of load-bearing and fatigue resistance. Part of the vehicle's weight is transmitted to the lower end of the shock absorber through the piston rod, and during vehicle operation, the piston rod repeatedly withstands tensile and compressive forces. Over time, the forces it experiences are complex. If the strength of the piston rod is insufficient, it is prone to bending, deformation, or even fracture, which could lead to serious consequences such as vehicle body loss of control.  From the perspective of actual driving experience, how does the quality of the piston rod directly affect the driving experience?The most obvious aspects are comfort and handling. A piston rod with high precision and a smooth surface ensures smooth movement of the piston and stable damping force. When driving over speed bumps or uneven roads, the shock can be smoothly absorbed. Conversely, if the piston rod is severely worn and has scratches on its surface, causing unstable damping force, the vehicle may experience bouncing and unstable steering when driving, and even the body may deviate when braking, affecting safety. Therefore, the piston rod not only affects comfort but also driving safety. Many people only focus on the piston seal when repairing shock absorbers, but they overlook the piston rod. In fact, the wear and deformation of the piston rod are the root cause of many shock absorber failures. For example, if there are scratches on the surface of the piston rod, it will wear out the seal during reciprocating motion, leading to oil leakage.  How to determine if the piston rod is normal? We can regularly inspect the piston rod of the shock absorber. If there is oil, rust on the surface or a distinct scratchy and uneven feeling when touched by hand, it indicates that there might be a problem. Additionally, if while driving, you notice a significant deterioration in the shock absorber's performance and increased body jolts, you should also check the piston rod for any bending or deformation.  The performance of shock absorbers largely depends on the quality of the piston rod. We hope everyone can pay more attention to the key components inside the shock absorbers. By being more observant during daily driving, we can make the shock absorption system more durable and drive with greater peace of mind.  The following introduces some requirements for the selection of materials and technical processing of piston rods:Generally, 45# steel is chosen. For some welded ones, 35# steel is selected. According to technical requirements, more than ten different processes are involved in the production process, and each process has strict technical and process requirements. For instance, quenching and tempering, and electroplating are included. The electroplating is hard chromium plating. Additionally, the dimensional tolerance requirements are extremely high because it needs to closely cooperate with oil seals, shock absorber oil, valve systems, etc. The straightness, ellipticity, roughness, and other aspects of the electroplating layer on the surface of the piston rod have extremely high requirements.

Cause A: The roughness of inner tube Ra is too high, or there are tiny welding slag and scratches on the inner wall, which wear down the PTFE layer like a "file".  Solution: If the cylinder wall roughness Ra is too high or contains weld spatters, it acts like a file. Ensure Ra ≤0.2 and implement strict cleaning protocols.   Cause B: Insufficient banding strength. It is a hot-press banding process, the cleanliness of the sinter piston surface or the failure of embedded PTFE material will cause the bands to separate from the powder metallurgy substrate.  Solution: Optimize parameter of heating temperature and time, clean the surface of sinter piston, redesign the grooves on the sinter piston.   Cause C: High-frequency operation raises oil temperature, causing PTFE bands fall down if the gap design between piston and working tube is not reasonable.  Solution: Verify the linear expansion coefficient and adjust tolerance fits to ensure clearance at 150℃.   Cause D: Additives in the shock oil may react with the band material, causing swelling or softening.  Solution: Conduct soaking tests to ensure full compatibility.

Although the oil seal is not big, it is crucial for the normal operation of the shock absorber and can be regarded as the sealing guardian of the shock absorber. So, what is the most crucial function of an oil seal? The primary function is to prevent leakage and seal. The hydraulic oil filled inside the shock absorber is the key medium for achieving the damping effect. The oil seal can closely adhere to the piston rod to prevent the leakage of hydraulic oil. Once it leaks, the damping force of the shock absorber will drop significantly, and the vehicle will experience obvious jolts, bouncing, and even the failure of the shock absorber during driving. Secondly, it is dust-proof and dirt-proof. Through the dual structure of the main lip and the dust-proof lip, it can effectively prevent external dust, sand and moisture from entering the interior of the shock absorber, avoiding wear and corrosion of internal precision components such as pistons and working cylinders, thereby extending the overall service life of the shock absorber. Apart from dust-proofing and leak-proofing. What other easily overlooked but very important functions do oil seals have? There are two key functions: One is to stabilize the damping performance. The oil seal can maintain the stability of the oil pressure and the cleanliness of the oil inside the shock absorber, ensuring that the damping force remains uniform under different working conditions such as high and low temperatures and high vibration frequencies, guaranteeing the smoothness and comfort of vehicle driving. The other is to reduce friction and noise. The oil seal lip and the piston rod form a thin layer of oil, which is the lubricating film. Reducing the friction during the reciprocating motion of the two can effectively lower the wear of components and also reduce abnormal noises. Additionally, the oil seal can adapt to high-pressure environments, prevent high-pressure gas from seeping in, and at the same time isolate moisture and ozone, slowing down the rate of its own aging. So, how to choose an proper oil seal? The core should be centered around four dimensions: compatibility, temperature and pressure resistance, material and craftsmanship, and brand reputation. Decisions should be made based on the type of shock absorber products, such as automotive hydraulic shock absorbers, motorcycle shock absorbers, and application scenarios like passenger cars, commercial vehicles, and construction machinery. This can be determined from two points. The first is to prioritize matching product specifications with working conditions and dimensional accuracy. The inner and outer diameters and thickness of the oil seal must be exactly matched with the piston rod and the working cylinder; otherwise, oil leakage or excessive wear will occur. When the shock absorber is in operation, it generates frictional high temperatures, and the hydraulic oil has a certain pressure. The recommended temperature range for the oil seal of the shock absorber in passenger vehicles is -40 ° C to +120 ° C. For commercial vehicles and functional machinery, higher temperature and pressure resistance, medium compatibility, and the material of the oil seal must be compatible with the oil used in the shock absorber to avoid swelling and hardening, which may lead to the failure of the shock absorber seal. Different types and specifications of oil seals should be matched according to sedans and off-road vehicles. For example, the reverse lock oil seal has an upper lip for dust prevention and a lower lip for oil sealing. There is a spring on each of the upper and lower lips, and an air sealing lip. When it is used in conjunction with the guide vane, it is in a state of oil and gas separation. This will improve the performance of the shock absorber and extend its service life. Before using the oil seal, it is advisable to apply special lubricating grease for better results. Some suggestions on oil seal selection and practical application:In addition to the material selection based on different working conditions mentioned above, attention should also be paid to dimensional accuracy. The thickness tolerance of the inner and outer diameters of the oil seal must be controlled within ± 0.10mm. The surface of the lip should be smooth without burrs; otherwise, it will affect the sealing effect and service life. During installation, it is essential to avoid scratching the lip with sharp tools. A dedicated oil seal sheath can be used for protection.

The answer is can. But it must never be driven normally, because there are no shock absorbers, the springs will keep bouncing repeatedly when encountering bumps, and the car body will sway up and down like a trampoline. Not only is the comfort very poor, but more terriably, the tires will frequently lift off the ground, the brakes and steering will fail, and the safety will be directly reduced. This situation is absolutely not allowed for our normal driving. Shock absorbers have two core functions. One is shock absorption, which is the buffering of shock absorption, quickly absorbing the vibrations caused by road bumps and preventing the vibrations from being directly transmitted to the vehicle body. The other is shock suppression, which is to prevent rebound and suppress the reciprocating bouncing of the springs, allowing the vehicle body to quickly return to stability. It is like the buffer and stabilizer of a vehicle, one end connected to the wheels and the other to the body, silently withstanding all the impacts from the road surface and providing a smooth and safe driving and riding experience.

The core components of a shock absorber are the coil spring and the damper. They are the soul partners of the shock absorber. The coil spring is responsible for supporting the weight of the vehicle body. Of course, the shock absorber also plays a certain supporting role. The spring is like the skeleton of the human body, firmly holding the vehicle body. The damper mainly responsible for suppressing the reciprocating motion of the spring. Without springs, the vehicle body would directly press against the wheels. Without shock absorbers, the springs would keep jumping non-stop. Both are indispensable. The second core component is the piston rod and the piston cylinder. The piston cylinder is also called the working cylinder. These two are the core of the shock absorber's movement. The piston rod is like a telescopic rod, with one end connected to the vehicle body and the other end connected to the piston. The piston moves repeatedly in the working cylinder because we have filled the working cylinder with shock absorber special oil, also known as hydraulic oil. There are many tiny valve holes on the piston. When the road surface is bumpy, the piston rod pushes the piston to move inside the cylinder. The hydraulic oil generates resistance through the valve port, which can convert the vibration energy into heat energy and consume it, achieving the effect of shock absorption. Here, it is important to emphasize the piston rod and the working cylinder. They have very high requirements for material precision. Even a millimeter-level error may lead to abnormal noise, oil leakage and the decline of shock absorber performance. The third core component is the special oil for shock absorbers, hydraulic oil, and the oil seal for sealing parts. Another one is the regulating valve. These are all relatively core auxiliary accessories. Don't underestimate these small accessories; they directly determine the lifespan and performance of the shock absorber. Especially the hydraulic oil and the oil seal, they will directly affect the lifespan of the shock absorber. Hydraulic oil is the medium for energy transmission and is responsible for transmitting pressure. Dissipating energy and deteriorating oil quality will directly affect the shock absorption effect. The oil seal, a protective guard for the sealing parts, mainly prevents the leakage of hydraulic oil and also stops dust, mud and other substances from the outside from entering the air reduction chamber, playing a protective role. Therefore, the aging of the sealing parts is one of the main reasons for the oil leakage of the shock absorber. What about the regulating valve? It's the piston and bottom valve inside the shock absorber. These valve systems mainly control the flow of hydraulic oil, thereby adjusting the hardness of the shock absorber. By adjusting the force value of the shock absorber, it can adapt to various road conditions because it can adjust the hardness and force value of the shock absorber.