The phenomenon and impact of Final Drive Hydraulic Oil Leak

Final drive leaking hydraulic oil is a common equipment failure phenomenon. When this happens, hydraulic oil will seep out from a specific part, which may appear as a slow drip or a more obvious flow.

Hydraulic oil leakage will not only cause a waste of resources, because hydraulic oil is an important working medium, and its leakage means that new hydraulic oil needs to be constantly replenished, increasing the cost of use. It may also affect the normal operation of the equipment, such as reducing the working efficiency of the equipment. Since the hydraulic system relies on hydraulic oil to transmit power and control actions, leakage will cause pressure to drop, making the equipment’s actions slow and inaccurate, or even unable to complete specific work tasks.

In addition, hydraulic oil leakage may also cause safety hazards. Leaking hydraulic oil may contaminate the working environment, make the ground slippery, and increase the risk of workers slipping and getting injured. In some specific work scenarios, such as where there is a fire source, leaking hydraulic oil may also cause a fire.

From a professional terminology perspective, hydraulic maintenance English is “Hydraulic maintenance”. Hydraulic system leakage refers to the phenomenon that a small amount of fluid flowing or temporarily stored in the cavity of hydraulic components and systems flows across the cavity boundary and flows out from the high-pressure side to the low-pressure side due to pressure, clearance, and other problems. This leakage is usually divided into two categories: internal leakage and external leakage. Internal leakage refers to the leakage of the working medium from the high cavity to the low cavity, such as the leakage of oil from the high-pressure cavity to the low-pressure cavity in the hydraulic transmission, and the leakage from the pressure channel in the reversing valve to the return oil channel; external leakage refers to the leakage of the working medium from the working cavity to the outside of the component and system, such as the cross-sectional leakage of the gear pump and the penetration of the hydraulic oil pipe. The leakage form can be divided into gap leakage, porous leakage, adhesion leakage, and power leakage.

Hydraulic system oil leakage can bring many hazards. First, the equipment efficiency decreases significantly and the energy loss gradually increases. With the leakage of hydraulic oil, the system pressure cannot be kept stable, resulting in the equipment consuming more energy to complete the same task when working. Secondly, the reliability of the equipment operation decreases. Leakage may cause unstable operation of the equipment, affecting the continuity of production and product quality. Furthermore, for some specific industries, such as light textiles and food, leaked hydraulic oil may pollute the products and also cause certain pollution to the environment. Finally, due to poor sealing, external pollutants are more likely to invade, resulting in a vicious cycle, causing early wear of the main engine or components, and in severe cases, the entire machine will be paralyzed.

Causes of Final Drive Hydraulic Oil Leak

1. Damage to hydraulic pipes

The main reason is that the hydraulic pipes are damaged, resulting in hydraulic oil leakage. Hydraulic pipes may be damaged due to various reasons during the operation of the equipment. For example, long-term use may cause the hydraulic pipes to age and wear, resulting in cracks or breakage. In addition, external physical impact may also cause damage to the hydraulic pipes. When the hydraulic pipe is damaged, hydraulic oil will leak out from the damaged part. Youdao Dictionary mentions “Not leak in the hydraulic oil, may also reduce the pressure. In the case of no leakage of hydraulic oil, the pressure may also be reduced.” This also explains the relationship between hydraulic pipe damage and hydraulic oil leakage and pressure changes.

2. Hydraulic oil pipe joints are not tightly sealed

Poor sealing at the joints is also one of the common causes of hydraulic oil leakage. The threads of the pipe joints on the fastening nuts and joints must be properly matched. Too loose or too tight may cause oil leakage; pay attention to alignment when installing the joints; the wrapping direction of the sealing tape must follow the direction of the thread rotation, generally 1 to 2 turns. The more layers are wrapped, the easier it is to loosen during the working stage, and in severe cases, it will cause leakage. If liquid nylon sealant is used as a filler between the thread and the buckle, the temperature must not exceed 60℃, otherwise it will melt and cause the hydraulic oil to overflow from the buckle; use flared thin pipe joints, first anneal the copper tube, and then process it into a round and smooth bell mouth; the connection between the welded pipe joints and the pipeline also needs to pay attention to the operating specifications to avoid leakage. There are various forms of hydraulic system leakage. Poor joint sealing is a type of external leakage, such as cross-section leakage of gear pumps and penetration of hydraulic oil pipes. Gran’s article also mentioned leakage caused by improper installation (assembly), among which the installation problem of pipe joints accounts for a large proportion of leakage accidents.

Solutions to Final Drive Hydraulic Oil Leak

1. Replace or repair damaged hydraulic pipes in time

Once the hydraulic pipe is found to be damaged, it should be replaced or repaired immediately to prevent oil leakage. Damage to the hydraulic pipe is one of the common causes of final drive leaking hydraulic oil. When the hydraulic pipe is damaged, the hydraulic oil will leak out from the damaged part, which not only wastes resources, but also may affect the normal operation of the equipment and even cause safety hazards. Therefore, it is very important to find and deal with the damage of the hydraulic pipe in time. You can judge whether the hydraulic pipe is damaged by regularly checking the appearance of the hydraulic pipe, observing whether there are signs of cracks, wear, etc., and checking whether the pressure of the hydraulic system is normal. If the hydraulic pipe is found to be damaged, it should be replaced with a new one immediately, or the damaged part should be repaired. When replacing or repairing the hydraulic pipe, make sure to use a hydraulic pipe of reliable quality and install it in strict accordance with the operating procedures to ensure the sealing and stability of the hydraulic system.

2. Ensure that the hydraulic oil pipe joints are well-sealed

Handle the joints that are not tightly sealed to ensure their sealing and prevent hydraulic oil leakage. Poor sealing of hydraulic oil pipe joints is also one of the common reasons for final drive leaking hydraulic oil. Poorly sealed joints can cause hydraulic oil to leak from the joints, affecting the normal operation of the equipment. To ensure that the hydraulic oil pipe joints are well sealed, attention should be paid to centering when installing the joints to avoid poor sealing caused by skewed joints. At the same time, it is necessary to select suitable sealing materials, such as sealing tape, liquid nylon sealant, etc., and install them strictly by the instructions. The winding direction of the sealing tape must follow the direction of the thread rotation, generally 1 to 2 turns. The more layers of winding, the easier it is to loosen during the working stage, and in severe cases, it will cause leakage. If liquid nylon sealant is used as a filler between the thread and the buckle, the temperature should not exceed 60℃, otherwise, it will melt and cause the hydraulic oil to overflow from the buckle. For flared thin pipe joints, the copper tube should be annealed first and then processed into a round and smooth bell mouth. The connection between the welded pipe joint and the pipeline also needs to pay attention to the operating specifications to avoid leakage. In addition, the sealing of the hydraulic oil pipe joints can be checked regularly, and problems can be dealt with in time to ensure the normal operation of the hydraulic system.