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The rotary system of drilling equipment enables the drill string and the drill bit to rotate, thereby penetrating the earth's strata and drilling a wellbore. It is mainly composed of the rotary table, top drive device, drill string, drill bit, and related control systems. The following is a detailed introduction for you: Ⅰ. Main Components Power Source: It provides power for the rotary system. Commonly used ones are diesel engines and electric motors. Large-scale drilling platforms may use multiple diesel engines or electric motors working jointly to meet the power demands of different drilling conditions. Transmission Device: It includes gear transmission, chain transmission, hydraulic transmission and other devices. Its function is to transmit the power of the power source to the drill string, so that the drill string drives the drill bit to rotate. For example, in the rotary table rotary system, the power is transmitted from the power source to the rotary table through gear transmission, and then the rotary table drives the kelly to rotate; in the top drive system, the power is directly transmitted to the top drive device at the top of the drill string through hydraulic or electrical transmission devices. Drill String: It is composed of drill pipes, drill collars, etc., and is an important component connecting the drill bit and surface equipment. It transmits the rotational power from the surface to the drill bit at the bottom of the well. At the same time, during the drilling process, it also plays the roles of conveying the drilling fluid and supporting the drill bit. Drill Bit: It is a tool that directly acts on the rock. According to different geological conditions and drilling requirements, there are various types, such as roller cone bits, PDC (Polycrystalline Diamond Compact) bits, etc. The drill bit, through various cutting structures, rotates and cuts the rock under the drive of the drill string to form a wellbore. Ⅱ. Rotary Table Structure: It is mainly composed of a driving device, a turntable, a main bearing, a sprocket, a braking device, etc. The driving device generally uses an electric motor or a hydraulic motor, and transmits the power to the turntable through the sprocket and chain. The main bearing supports the turntable to enable it to rotate smoothly. The braking device is used to stop the rotation of the turntable when necessary. Working Principle: The driving device provides power, drives the turntable to rotate through the sprocket and chain. There are square bushings on the turntable, and the kelly is inserted into the square bushings. As the turntable rotates, the kelly drives the drill string and the drill bit to rotate together, thus achieving the purpose of breaking the rock. Application Scenarios: It is widely used in various types of onshore and offshore drilling platforms. It is a commonly used rotary component in traditional drilling equipment, especially showing good applicability in the drilling operations of some shallow and medium-deep wells. Ⅲ. Top Drive Device Structure: It is usually composed of a drilling rotary swivel, an electric motor, a gearbox, a main shaft, a balance system, etc. The swivel provides a passage for high-pressure drilling fluid for the drill string. The electric motor serves as the power source, and transmits the power to the main shaft through the gearbox, and the main shaft drives the drill string to rotate. The balance system is used to balance the weight of the top drive device and reduce the load on the derrick. Working Principle: The electric motor drives the gearbox, and the output shaft of the gearbox is connected to the main shaft, driving the main shaft to rotate, and then driving the drill string and the drill bit connected below the main shaft to rotate. At the same time, the drilling fluid enters the inside of the drill string through the swivel and is ejected from the drill bit, realizing the circulation and cuttings-carrying functions of the drilling fluid. Application Scenarios: It is widely used in the drilling operations of deep wells, ultra-deep wells and complex formations. It can improve the drilling efficiency and reduce the time for making up drill pipes. It is especially suitable for situations where frequent tripping of the drill string and control of complex wellbore trajectories are required. Ⅳ. Drill String Structure: It is mainly composed of drill pipes, drill collars, heavy-weight drill pipes, etc. The drill pipe is the main component of the drill string, usually made of high-strength steel pipes, and is used to connect the drill bit and the wellhead equipment, transmitting torque and drilling fluid. The drill collar is located at the lower part of the drill string, close to the drill bit. It has a relatively large weight and is used to apply the drilling pressure to the drill bit to ensure that the drill bit can effectively break the rock. The heavy-weight drill pipe is used between the drill pipe and the drill collar to adjust the weight and stiffness of the drill string.  Working Principle: In the rotary system, the drill string rotates with the rotation of the rotary table or the top drive, transmitting the torque from the wellhead to the drill bit, enabling the drill bit to cut the rock. At the same time, the inside of the drill string is the passage for the drilling fluid. The drilling fluid flows downward from the inside of the drill string under the action of the pump, and after being ejected from the drill bit, it carries the cuttings back to the wellhead. Application Scenarios: It is applicable to various drilling operation environments. Drill strings are indispensable for drilling operations from shallow wells to deep wells, and from onshore to offshore drilling platforms. Different well depths, formation conditions and drilling process requirements will require the selection of drill strings of different specifications and materials. Ⅴ. Drill Bit Structure: The structure varies according to different types. A common roller cone bit is composed of cones, legs, bearings, etc. There are teeth on the cones, and the rock is cut through the rolling of the cones and the breaking action of the teeth. The PDC bit uses diamond compact slices as cutting elements, which are fixed on the bit body. Working Principle: During the rotation of the roller cone bit, the cones roll and come into contact with the rock surface, and the teeth produce impact and extrusion effects on the rock, causing the rock to break. The PDC bit relies on the high hardness and wear resistance of the diamond compact slices to break the rock by cutting, and has a relatively high drilling efficiency. Application Scenarios: The roller cone bit is suitable for various hardness formations, especially performing well in hard formations and abrasive formations. The PDC bit has obvious advantages in soft to medium-hard formations and can achieve rapid drilling. Ⅵ. Control System of the Rotary System Structure: It includes an operation control console, sensors, a controller, etc. The operation control console is the interface for operators to control the rotary system. It is equipped with various buttons, knobs and a display screen, which are used to set parameters such as the rotation speed and torque. Sensors are distributed in various key parts of the rotary system, such as the electric motor, gearbox, drill string, etc., and are used to monitor the running status of the system in real time, such as the rotation speed, torque, temperature, etc. The controller precisely controls each component of the rotary system according to the settings of the operator and the information fed back by the sensors. Working Principle: The operator sets the working parameters of the rotary system through the operation control console. The controller, according to these set values and the actual operation data fed back by the sensors, adjusts the rotation speed of the electric motor, controls the start and stop of the braking device, etc., so that the rotary system operates in the set working state. For example, when the sensor detects that the torque of the drill string is too large, the controller will automatically reduce the rotation speed of the electric motor to prevent the drill string from being damaged due to overload. Application Scenarios: In various drilling operations, the control system plays a vital role. It can ensure the safe and efficient operation of the rotary system and adapt to different drilling process requirements and changes in formation conditions. Ⅶ. Common Faults and Solutions of the Rotary System of Drilling Equipment are as follows: Faults of the Rotary Table The rotary table rotates inflexibly or there is a jamming phenomenon Reasons: The main bearing of the rotary table is worn or damaged, resulting in an increase in the rotation resistance; the chain is too tight or the sprocket is worn, affecting the power transmission; there is foreign matter stuck between the turntable and the base; the clearance between the square bushing and the kelly is too small or the wear is uneven. Solutions: Check the main bearing, and replace it in time if it is worn or damaged; adjust the tightness of the chain, check the wear condition of the sprocket, and replace the sprocket if necessary; clean up the foreign matter between the turntable and the base; check the matching condition of the square bushing and the kelly, adjust the clearance or replace the worn parts. The rotary table leaks oil Reasons: The seals are aged or damaged, resulting in the leakage of lubricating oil; the oil pool level is too high, and the lubricating oil overflows from the seals; the oil pipe joint is loose or damaged, causing oil leakage. Solutions: Replace the aged or damaged seals; check the oil pool level and adjust it to an appropriate height; tighten the oil pipe joint, and replace the joint in time if it is damaged. Faults of the Top Drive Device Faults of the top drive motor Reasons: The motor is overloaded or overheated, resulting in the burnout of the motor winding; the motor bearing is damaged, causing the vibration and noise of the motor; there are faults in the electrical control system, such as contactor faults, line short circuits, etc., affecting the normal operation of the motor. Solutions: Check the load condition of the motor, avoid overload operation, and improve the heat dissipation conditions of the motor; replace the damaged motor bearing; check the electrical control system, and repair or replace the faulty contactors, lines and other components. The top drive swivel leaks water Reasons: The seals of the swivel are worn or aged, resulting in the leakage of the drilling fluid; the wash pipe is worn, affecting the sealing effect; the connection part between the central pipe and the gooseneck pipe is loose or the seal is damaged. Solutions: Replace the seals of the swivel; check the wear condition of the wash pipe and replace the wash pipe in time; tighten the connection part between the central pipe and the gooseneck pipe, and replace the seal if it is damaged. Faults of the Drill String Drill pipe fracture Reasons: The drill pipe is used for a long time, and the fatigue damage accumulates; the drill pipe is subjected to excessive torque, tension or bending force during the drilling process; there are defects in the drill pipe material or problems in the processing quality. Solutions: Regularly perform flaw detection on the drill pipe, and timely find and replace the drill pipes with fatigue damage; optimize the drilling parameters to avoid the drill pipe from bearing excessive loads; strictly control the purchase quality of the drill pipe and select high-quality drill pipes. Drill string sticking Reasons: The performance of the drilling fluid is not good, the filtration loss is large, and a thick mud cake is formed on the wellbore wall, resulting in an increase in the friction between the drill string and the mud cake; the wellbore trajectory is irregular, and there are places with a large dogleg severity, causing local stress concentration of the drill string; the drill string remains stationary for a long time, and adhesion occurs between the drill string and the wellbore wall. Solutions: Adjust the performance of the drilling fluid, reduce the filtration loss, and improve the quality of the mud cake; optimize the wellbore trajectory and reduce the dogleg severity; regularly move the drill string to avoid long-term stationary. Faults of the Drill Bit The drill bit wears too quickly Reasons: The drill bit is not properly selected and is not suitable for the current formation conditions; the drilling parameters are not reasonable, such as excessive drilling pressure and too high rotation speed; the performance of the drilling fluid is not good, and the lubrication and cooling effects on the drill bit are poor. Solutions: Select the appropriate drill bit type according to the formation lithology; optimize the drilling parameters and reasonably adjust the drilling pressure and rotation speed; improve the performance of the drilling fluid and enhance its lubrication and cooling effects. Drill bit balling Reasons: The viscosity and yield point of the drilling fluid are too high, the cuttings are not easy to be discharged, and they adhere to the drill bit; the water holes of the drill bit are blocked, the displacement of the drilling fluid is insufficient, and the drill bit cannot be effectively cleaned; the formation lithology is prone to water absorption and swelling, and a mud cake is formed and adheres to the drill bit. Solutions: Adjust the viscosity and yield point of the drilling fluid to improve its cuttings-carrying capacity; check the water holes of the drill bit, clean up the blockages, and ensure the normal displacement of the drilling fluid; for formations prone to water absorption and swelling, add anti-swelling agents and other treatment agents to improve the formation conditions.

The hoisting system in oil drilling is a crucial component of oil drilling equipment, mainly used for tripping drill strings and casings, as well as suspending drill strings during drilling operations. The following are some of the main equipment in this system: Ⅰ. DerrickStructural Features: The derrick is a large-scale steel structure, usually including types such as the tower-shaped derrick, A-shaped derrick, and mast derrick. The tower-shaped derrick has an overall tower-like structure, with high stability and load-bearing capacity, capable of withstanding large loads. However, it is large in size, heavy in weight, and relatively complex in disassembly, assembly, and transportation. The A-shaped derrick is composed of two inclined brackets and a top crossbeam, resembling the letter "A" in shape. It has a compact structure, is convenient for disassembly and assembly, and is widely applied. The mast derrick is relatively low and has a small footprint, suitable for places with limited space.Function: The derrick provides support and fixation for the entire hoisting system. Through its steel structure framework, it bears the weights of equipment such as the crown block, traveling block, and drill string, as well as various tensile forces and pressures generated during the hoisting process. It enables the drill string to be raised and lowered vertically, and provides installation positions for hoisting equipment and tools such as the crown block, traveling block, rotary swivel, (top drive) power tongs, and elevator. It also ensures that operators have sufficient space for drilling operations. Ⅱ. Crown Block Structural Composition: Installed at the top of the derrick, it is a fixed sheave block composed of multiple sheaves.The crown block sheaves are usually made of high-quality steel, with high wear resistance and strength to withstand the huge tensile forces generated by frequent hoisting and lowering operations.Function: It changes the direction of the wire rope, transmits the pulling force of the drawworks to the traveling block, and realizes the hoisting and lowering of the drill string. Through the combination of multiple sheaves, it can effectively distribute the pulling force, reduce the load borne by a single sheave, and improve the reliability and safety of the system. Ⅲ. Traveling BlockStructural Features: Connected to the crown block by a wire rope, it is a movable sheave block, usually composed of multiple sheaves, which cooperates with the sheave block of the crown block through the wire rope to form a labor-saving hoisting system. The number and size of the sheaves are determined according to the load-bearing capacity of the traveling block and the requirements of the drilling operation. The lower part of the traveling block is connected to the drill string through the traveling block hook. Under the action of the hoisting system, it drives the drill string to move up and down. The structural design of the traveling block should ensure its flexibility and stability during movement, and it should be able to withstand the weight of the drill string and the impact force during the hoisting process.Function: Driven by the drawworks, it moves the drill string up and down through the pulling of the wire rope. Since the traveling block is a movable sheave block, according to the principle of labor-saving of the sheave block, it can amplify the pulling force of the drawworks, enabling the hoisting of heavier drill strings. Ⅳ. HookStructural Composition: The hook is connected below the traveling block, suspending the drill string through the hook body, and forms a hoisting system together with the traveling block, crown block, and drawworks. The hook has a rotatable hook body and a safety locking device.Function: Its working principle is relatively simple. It mainly uses its own structural features and connection devices to transmit the pulling force of the traveling block to the drill string, facilitating the connection and separation with the joint of the drill string, and preventing the drill string from accidentally falling off during the hoisting process. The rotating function of the hook body allows the drill string to rotate as needed during the hoisting and lowering process. For example, when connecting or disassembling drill pipes, it enables the threads of the drill pipes to be accurately aligned. The safety locking device of the hook prevents the hook body from accidentally opening after the drill string is suspended, ensuring that the drill string will not fall off and guaranteeing the safety of the operation. The load-bearing capacity of the hook varies according to the depth of the well and the weight of the drill string, generally ranging from several dozen tons to several hundred tons. Ⅴ. DrawworksThe drilling drawworks is not only the main equipment of the hoisting system but also the core part of the entire drilling and workover rig, and it is one of the three major working units of the drilling and workover rig. A classic three-axis electric-driven drilling rig.Structural Features: As the power equipment of the hoisting system and the power source, it is usually driven by an electric motor or a diesel engine. The drawworks contains components such as a transmission device, a drum, and a braking system.Function: It controls the lifting speed and position of the traveling block and the drill string by winding and unwinding the wire rope. The transmission device can transmit power to the drum at different rotation speeds and torques according to different operation requirements. When the drill string needs to be hoisted, the drum rotates forward and winds the wire rope, thus pulling the traveling block and the connected drill string upward; when lowering the drill string, the drum rotates in reverse and releases the wire rope, and the drill string slowly descends under its own gravity. The braking system uses components such as brake pads or brake discs to quickly stop the rotation of the drum when necessary, making the drill string stop at the specified position and achieving the hovering function, ensuring the safety and precise control of the operation. Ⅵ. Wire RopeStructural Features: Made of high-strength and corrosion-resistant steel, it has high breaking tensile force and good flexibility. Generally, it is twisted by multiple strands of steel wires, and the outer layer may also have a protective layer to improve its wear resistance and corrosion resistance. In order to ensure the service life and safety of the wire rope, it is necessary to regularly inspect, lubricate, and replace it. When selecting a wire rope, an appropriate one should be determined according to factors such as the depth of the well and the load.Function: It connects the crown block, traveling block, and drawworks, transmits the pulling force, and suspends the drill string. During the drilling process, the wire rope needs to bear a huge pulling force, so its quality and performance directly affect the safety and reliability of the hoisting system. The wire rope bypasses multiple sheaves of the crown block and traveling block to form a multi-strand rope system. According to the principle of labor-saving of the sheave block, in this way, the drawworks only needs to provide a pulling force smaller than the gravity of the drill string to achieve the hoisting of the drill string. For example, a crown block and traveling block system composed of multiple sheaves can amplify the pulling force of the drawworks several times, enabling the hoisting of drill strings weighing dozens of tons or even hundreds of tons. At the same time, the sheave block can also change the direction of the force, allowing the drawworks to be operated in a more convenient position while the drill string can be raised and lowered vertically. In addition, the oil drilling hoisting system may also include some auxiliary equipment, such as the anti-collision device for preventing the traveling block from rising too high and colliding with the crown block, and the dead rope anchor for fixing one end of the wire rope. These devices work together to ensure that the oil drilling hoisting system can operate safely and efficiently, and complete the operations such as tripping drill strings and casings during the oil drilling process.

The oil drilling rotary swivel is a key piece of equipment in oil, gas and other drilling operations. Today, let's learn about the rotary swivel together. Ⅰ.Working Principle During the drilling process, the swivel is suspended on the traveling block and connected to it through the bail. The winch pulls the traveling block through the wire rope, thus driving the swivel to move up and down. The power equipment (such as the rotary table or top-drive) drives the drill string to rotate, and the central tube of the swivel rotates accordingly, enabling the drill string to carry out rotary drilling. At the same time, the drilling fluid is pumped out from the surface mud pump, enters the central tube through the gooseneck tube, and then flows to the bit through the inside of the drill string, cooling and lubricating the bit and carrying the cuttings to the surface. Ⅱ.Main Functions Torque Transmission: In cooperation with the rotary table or top-drive, it transmits power to the drill string, allowing the bit to rotate and break the rock. Load-Bearing: It suspends the rotating drill string, bears most or even all of the weight of the drill string, provides upper bearing support for it, and at the same time bears various axial and radial loads generated during the drilling process to ensure the stability of the drilling operation. Drilling Fluid Conveyance: As a passage for the drilling fluid, it introduces high-pressure drilling fluid into the rotating drill string, conveys the drilling fluid prepared on the surface to the wellbore, and plays roles such as cooling the bit, carrying cuttings, and stabilizing the wellbore. Ⅲ.Requirements for the Swivel Strength and Rigidity of Load-Bearing Parts: All load-bearing parts need to have sufficient strength and rigidity to bear the entire weight of the drill string and various axial and radial loads generated during the drilling process. For example, for a well several kilometers deep, the weight of the drill string can reach hundreds of tons. The load-bearing components of the swivel, such as the bail and main bearings, need to be reasonably designed and made of excellent materials to meet the load-bearing requirements. Reliable Sealing System: The high-pressure drilling fluid sealing system must work reliably, have a long service life, and be quickly and conveniently replaced to prevent the leakage of drilling fluid and the entry of external impurities. Good Rotation Performance: It should ensure that the drill string can rotate flexibly and stably, with a low friction coefficient and high rotation accuracy. High-quality bearings and a reasonable structural design are the keys to achieving good rotation performance. Good Oil Sealing: The oil seal should be in good condition and be able to automatically compensate for the wear of the sealing elements during the working process. Ⅳ.Composition and Structural Features The swivel generally consists of the following three parts: Load - Bearing SystemIt includes the central tube and its joints, the housing, the trunnions, the lifting bail, and the main bearings, etc. 1.Central Tube: As a passage for the drilling fluid, its internal space allows the drilling fluid to flow smoothly from the surface to the bit. The central tube needs to have good wear - resistance and corrosion - resistance to withstand the long - term scouring and erosion of the drilling fluid. 2.Lifting Bail: It is used to suspend the swivel. By connecting with the traveling block, the swivel can move up and down with the traveling block, thus realizing the tripping operation of the drill string. The bail needs to have sufficient strength to bear the weight of the drill string and various loads generated during the drilling process. 3.Main Bearings: They support the rotation of the central tube, enabling the drill string to rotate flexibly. The main bearings need to have characteristics such as high load-bearing capacity, low friction coefficient, and long service life to ensure stable operation during long-term drilling operations.The weight of the drill string is transmitted to the hook through the kelly, the central tube, the main bearings, the housing, the trunnions, and the bail. Drilling Fluid SystemIt includes the gooseneck tube and the drilling fluid washpipe assembly. 1.Gooseneck Tube: It connects the surface drilling fluid circulation system and the central tube. Its shape is usually gooseneck-like, which is convenient for the introduction of the drilling fluid and, to a certain extent, alleviates the impact force when the drilling fluid flows. 2.Washpipe Assembly: It is installed outside the central tube and plays a sealing role to prevent the drilling fluid from leaking from the gap between the central tube and the swivel housing. The washpipe assembly usually consists of a washpipe, sealing elements, etc. The performance of the sealing elements directly affects the sealing effect of the swivel.High-pressure drilling fluid flows into the rotating central tube through the gooseneck tube and the washpipe and reaches the inside of the drill string. Drilling fluid sealing devices are installed at the upper and lower parts of the washpipe to prevent the leakage of high-pressure drilling fluid. Auxiliary SystemIt includes the centralizing bearings, anti-jump bearings, and oil seal devices.The inner cavity of the housing forms an oil sump to lubricate the main bearings, centralizing bearings, and anti-jump bearings.The upper and lower oil seal boxes are mainly used to prevent the drilling fluid, oil, and water from leaking into the oil sump and the leakage of oil, to ensure the normal operation of each bearing.The upper and lower centralizing bearings radially position the central tube to ensure its stable operation with small swing, to improve the working conditions of the drilling fluid and oil seals and extend their service life.The anti-jump bearings are used to bear the impact and vibration transmitted by the drill string during the drilling process and prevent the axial movement of the central tube. Ⅴ.Maintenance and Upkeep of the Drilling Swivel Daily Inspection 1.Appearance Inspection: Check the appearance of the swivel daily to see if there are obvious signs of wear, cracks, deformation, or leakage. Pay special attention to key parts such as the gooseneck tube, central tube, and bail, as well as the sealing conditions of all connection parts. 2.Connection Parts Inspection: Check whether all connection bolts and nuts are loose to ensure that the connection between the bail and the traveling block, the connection between the gooseneck tube and the drilling fluid manifold, and the connection between the central tube and the drill string are firm and reliable. Loose connections may lead to leakage or equipment failure. 3.Drilling Fluid Passage Inspection: Observe the flow of the drilling fluid to ensure that the drilling fluid passage is unobstructed. Check for any blockages or abnormal pressure fluctuations. If there are any abnormalities, clean or investigate the cause in a timely manner. Lubrication Maintenance 1.Bearing Lubrication: Regularly lubricate the rotating parts of the swivel, such as the main bearings and auxiliary bearings. Use the appropriate lubricant according to the recommendations of the equipment manufacturer and control the amount of lubricant. Over-lubrication may lead to seal failure, while insufficient lubrication will accelerate bearing wear. Generally, set a reasonable lubrication cycle according to the operating environment and usage frequency, such as lubricating after a certain number of working hours or after completing a certain amount of drilling footage. 2.Sealing Element Lubrication: For sealing elements, such as the washpipe seals, proper lubrication is also required to reduce friction and wear and improve the sealing performance. Use a special seal lubricant and apply it according to the specified method and frequency. Maintenance of Rotating Parts 1.Bearing Inspection and Maintenance: In addition to lubrication, regularly check the operating conditions of the bearings, such as whether there are abnormal noises, vibrations, or heat-generation phenomena. If problems are found with the bearings, repair or replace them in a timely manner. Tools such as vibration monitors and temperature sensors can be used to monitor the bearings to detect potential problems at an early stage. 2.Central Tube Rotation Inspection: Ensure that the central tube can rotate flexibly without jamming. Check whether the fit clearance between the central tube and other components is normal. If there are any abnormalities, adjust or repair them in a timely manner. Regular Maintenance and Repair 1.Maintenance Plan Formulation: Formulate a detailed maintenance plan according to the recommendations of the equipment manufacturer and the actual usage situation, including regular comprehensive inspections, maintenance, and repair work. Carry out maintenance according to the plan to ensure that the equipment is always in good operating condition. 2.Professional Repair: For complex faults or repair work, it should be operated by professional repair personnel. The repair personnel should have relevant knowledge and skills, be familiar with the structure and working principle of the swivel, and use appropriate tools and equipment for repair to ensure the repair quality. Ⅵ.Common Faults and Troubleshooting Methods of the Drilling Swivel Leakage of Mud at the Connection between the Gooseneck Tube and the Swivel Flange or the Union of the Water Hose Deterioration or Damage of the Short-shaped Rubber Gasket: Replace the short-shaped rubber gasket. Rust or Damage of the Sealing Surfaces: Clean, derust, or weld - repair each sealing surface. High Temperature and Short Service Life of the Washpipe Lower Packing Box Assembly during Operation Blockage of the Lubricating Oil Nozzle, Inability to Inject Lubricating Grease: Disassemble and clean the blockage of the oil nozzle or replace the parts. Too Tight Fit between the Packing Lip and the Washpipe Sealing Surface            Over-tightening of the Lower Packing Cap: Loosen it and then appropriately adjust the tightness of the lower cap.            Too Small Inner Diameter of the Packing Lip or Too Large Outer Diameter of the Washpipe: Select the appropriate washpipe and packing for assembly. Unsmooth Swing of the Bail or Loose Fit with the Pin Rust or Foreign Matter in the Pin and the Bail Hole: Clean, derust, remove the foreign matter, and then inject lubricating grease. Serious Wear of the Pin and the Hole due to Lack of Oil             Blockage of the Oil Nozzle: Clean the oil nozzle.             Wear of the Pin: Replace the pin. Overheating of the Swivel Housing, Temperature Exceeding 60℃ Lack of Lubricating Oil: Add oil to the oil level gauge scale. Excessive Oil Addition: Open the plug to drain the oil to the oil level gauge scale. Entry of Mud and Other Impurities into the Lubricating Oil: Disassemble the oil drain plug, drain all the oil, clean the housing, and add new oil to the oil level gauge scale. Serious Oil Leakage from the Lower Oil Packing Box during Operation, No Oil in the Housing:Disassemble and inspect to replace the worn-out oil seal sleeves, oil seals, packing and other sealing parts.