A bearing cage reciprocating phosphating process and production line

Abstract

A bearing cage reciprocating phosphating process and production line, comprising a main frame, a tool loading unit, a phosphating tank unit, a liquid storage tank unit and an automatic transfer assembly. The production line performs the following steps: loading the workpiece; placing the workpiece in the degreasing liquid, uniformly mixing the degreasing liquid by gas bubbling; first pure water cleaning; pickling treatment; second pure water cleaning; immersing the workpiece in the surface conditioning liquid, uniformly mixing the surface conditioning liquid by gas bubbling; immersing the workpiece in the phosphating liquid, and driving the workpiece to rotate around the central axis thereof; third pure water cleaning; air cutting off water and applying rust-proof oil; unloading the workpiece. The present application realizes automatic transfer of the workpiece between processes by a gantry mechanical arm, gas bubbling devices are arranged in the degreasing tank and the surface conditioning tank, and a rotating driving mechanism is arranged in the phosphating tank, effectively improving the automation degree of the phosphating process and the uniformity of the phosphating film, and ensuring the consistency and stability of the product quality.

Description

Technical Field

[0001] This invention relates to the field of metal surface treatment technology, specifically to a reciprocating phosphating process and production line for bearing cages. Background Technology

[0002] As a key component of rolling bearings, the bearing cage's function is to evenly separate the rolling elements and guide them to roll smoothly between the inner and outer rings of the bearing. The surface quality of the bearing cage directly affects the bearing's assembly accuracy, rotational flexibility, vibration and noise levels, and service life. Phosphating is one of the most widely used metal surface treatment technologies in industry. By forming a phosphate chemical conversion film with a microporous structure on the metal surface, it can significantly improve the surface hardness, wear resistance, corrosion resistance, and coating adhesion of the workpiece. Simultaneously, the porous structure of the phosphate film also has excellent oil retention properties, effectively improving lubrication conditions during bearing operation.

[0003] Currently, the phosphating treatment of bearing cages in the industry still widely adopts the traditional process route. The basic flow is: manual loading → degreasing → water washing → pickling → water washing → surface conditioning → phosphating → water washing → drying → oil immersion → manual unloading. The processing tanks for each step are arranged sequentially, and the workpieces are transferred between tanks manually by operators or with the aid of simple overhead cranes. Although a few companies have introduced semi-automated overhead crane systems to achieve mechanical transfer of workpieces, their overall process control methods remain relatively rudimentary, specifically manifested in the following aspects: 1. Slow production cycle, making it difficult to meet the demands of large-scale production. In existing processes, the loading, unloading, and transfer of workpieces between processing steps heavily rely on manual operation. Each batch has a long processing cycle, and operators must frequently perform repetitive physical labor such as handling and lifting, severely limiting production efficiency and capacity. With the increasing demand for bearing cages in the bearing industry, traditional manual or semi-automatic operation modes are no longer suitable for the requirements of large-volume, high-efficiency continuous production.

[0004] 2. Insufficient precision in process parameter control leads to poor product quality consistency. The quality of phosphating treatment is highly dependent on process parameters such as processing time, bath temperature, workpiece immersion posture, and bath uniformity. Under current technological conditions, the control of these parameters suffers from the following specific deficiencies: (1) Processing time relies on manual experience and lacks precise timing and automatic control. Operators rely on experience to judge the start and end times of each process. There are significant differences in processing time between different batches and even between different workpieces in the same batch, resulting in large fluctuations in the thickness of the phosphating film and making it difficult to ensure product consistency.

[0005] (2) Unstable temperature control of the bath solution. Key processes such as degreasing, surface conditioning and phosphating have specific temperature requirements (such as phosphating temperature, which is usually between 80℃ and 95℃). However, existing equipment mostly adopts simple heating methods and lacks precise constant temperature control. Temperature fluctuations directly affect the chemical reaction rate and the crystal morphology of the phosphating film.

[0006] (3) The workpiece remains stationary in the treatment tank, resulting in poor surface treatment of complex surfaces. The bearing cage has a conical main structure and multiple windows distributed on the conical surface, making its geometry relatively complex. During the phosphating process, when the workpiece is stationary and immersed in the phosphating solution, air bubbles are easily trapped on the inner conical surface, the edges of the windows, and inside the pores, forming localized shielding. This makes it difficult to completely cover these areas with phosphating film or results in insufficient film thickness, seriously affecting the overall corrosion resistance and lubrication performance of the bearing cage.

[0007] (4) Poor uniformity of the bath solution and obvious local concentration gradient. The degreasing solution and surface conditioning solution lack effective circulation and stirring methods during the treatment process, and the bath solution is prone to concentration stratification and temperature stratification. The reaction environment of different areas of the workpiece or different parts of the same workpiece is inconsistent, resulting in incomplete degreasing and uneven surface conditioning, which in turn affects the fineness of the subsequent phosphating film crystals and adhesion.

[0008] 3. Severe cross-contamination between processes makes it difficult to maintain process stability. When workpieces are transferred between processing tanks, their surfaces inevitably carry over solutions from the previous process into the next. Especially in the absence of effective spray rinsing, degreasing solution entering the pickling tank neutralizes the effective components of the acid, and pickling solution carried into the phosphating tank disrupts the acid-base balance of the phosphating solution, leading to shortened solution life, decreased process stability, and the need for frequent solution replacement, increasing production costs and downtime.

[0009] 4. Low level of automation, unable to achieve closed-loop control of the entire process. In existing production lines, there is a lack of a unified automated scheduling system between processing units. Operations such as workpiece transfer, process start and stop, and process parameter adjustment all require manual intervention, making it difficult to achieve full-process automation, informatization, and intelligent management. The traceability and controllability of the production process are insufficient.

[0010] In addition, the existing production lines lack systematic waste gas collection and treatment devices, and harmful gases such as acid mist and alkali mist are directly emitted into the workshop environment, which not only endangers the health of operators, but also causes corrosion damage to workshop equipment and building structures, which does not meet the requirements of modern industry for green and environmentally friendly production.

[0011] In summary, existing bearing cage phosphating technologies have significant shortcomings in terms of production efficiency, quality control, automation level, and operating environment. With the downstream bearing industry's increasing demands for product quality and increasingly stringent environmental regulations, there is an urgent need to develop a highly automated, precisely controlled, stable, reliable, and environmentally friendly bearing cage phosphating process and production line to solve the aforementioned long-standing technical problems. Summary of the Invention

[0012] The purpose of this invention is to provide a reciprocating phosphating process and production line for bearing cages, in order to solve the problems of low processing efficiency, unstable quality, low degree of automation and poor working environment in the existing technology.

[0013] To achieve the above objectives, the present invention provides the following technical solution: A reciprocating phosphating process and production line for bearing cages includes a main frame, a tooling loading unit, an isolation group, a phosphating tank unit, a liquid storage tank unit, and an automatic transfer assembly. The main frame serves as the load-bearing skeleton of the production line, and the functional units are sequentially arranged on the main frame. This production line is used to perform an automated phosphating process.

[0014] The automated phosphating treatment method includes the following steps: S101: Tooling Loading. The bearing cage workpieces to be processed are loaded into the tooling by the tooling loading unit. The tooling is configured to fix multiple bearing cage workpieces and maintain the stability of the workpieces' posture during transfer and processing.

[0015] S102: Degreasing treatment. An automatic transfer assembly immerses the workpiece in a degreasing solution to remove contaminants such as rust-preventive oil, lubricating oil, dust, and machining residue from the workpiece surface. During degreasing, gas is introduced into the degreasing tank via a gas bubbling device. The agitation of the bubbles evenly mixes the degreasing solution, ensuring sufficient contact between the solution and the workpiece surface, thus improving degreasing efficiency and effectiveness. Preferably, the degreasing tank is equipped with a first heating device to heat and maintain the degreasing solution at 60°C.

[0016] S103: First water wash. Immerse the degreased workpiece in a pure water bath for the first wash to remove residual degreaser and detached oil from the workpiece surface.

[0017] S104: Pickling treatment. The workpiece after the first cleaning is immersed in pickling solution for pickling treatment to remove oxide scale and rust from the workpiece surface, activate the metal surface, and provide a clean substrate surface for subsequent phosphating treatment.

[0018] S105: Second water wash. The pickled workpiece is immersed in pure water for a second wash to remove residual pickling solution and reaction products from the workpiece surface. Preferably, the pure water tank used to perform this step is configured to allow the tooling to move and switch flow directions within it to optimize the cleaning effect and production line layout.

[0019] S106: Surface Conditioning Treatment. The workpiece after the second cleaning is immersed in a surface conditioning solution for surface conditioning treatment to eliminate the problem of coarse phosphating film crystals caused by pickling or strong alkali degreasing, and to accelerate the formation of a fine and dense phosphating film. During the surface conditioning process, gas is introduced into the surface conditioning tank through a gas bubbling device, and the surface conditioning solution is uniformly mixed by the agitation of the bubbles, ensuring that the surface conditioning solution is in full and uniform contact with the workpiece surface. Preferably, the surface conditioning tank is equipped with a second heating device to heat and maintain the surface conditioning solution in the tank at 50°C.

[0020] S107: Phosphating Treatment. The surface-conditioned workpiece is immersed in a phosphating solution for phosphating treatment, and the workpiece is controlled to rotate around its central axis. A rotary drive mechanism drives the workpiece to rotate slowly at a preset speed, ensuring that the phosphating solution evenly covers all surfaces of the workpiece, especially the inner holes of the bearing cage and complex geometric areas, ensuring a uniform phosphating film thickness and fine crystals. Preferably, the rotary drive mechanism is configured to drive the workpiece to rotate at a speed of 1 revolution per 5 minutes. Preferably, the phosphating tank is equipped with a third heating device for heating and maintaining the phosphating solution in the tank at 90°C.

[0021] S108: Third wash.

[0022] S109: Air removal and rust prevention treatment. After phosphating, the workpiece is subjected to air removal and rust prevention oil is applied to remove residual moisture from the workpiece surface and form a rust-preventive protective layer.

[0023] S110: Workpiece unloading. The workpiece that has undergone rust prevention treatment is unloaded from the tooling, completing the entire phosphating process.

[0024] Preferably, the automatic transfer component is a gantry robotic arm system, used to realize the automatic transfer of workpieces between various processing units on the main frame. The gantry robotic arm system includes a traveling mechanism, a lifting mechanism, a rotating mechanism, and a gripping mechanism. The traveling mechanism can move along the length of the main frame, the lifting mechanism can extend and retract vertically, the rotating mechanism is used for rotating the tooling, and the gripping mechanism is used for gripping and releasing the tooling. The PLC control system drives the gantry robotic arm to sequentially transfer the tooling to each processing unit according to a preset process sequence and time.

[0025] Preferably, the production line further includes a liquid storage tank unit, which includes a degreasing tank and a surface conditioning tank. Both the degreasing tank and the surface conditioning tank are equipped with gas bubbling devices to perform the gas bubbling and mixing operations in steps S102 and S106.

[0026] Preferably, the degreasing tank is equipped with a first heating device for heating the degreasing liquid in the tank and maintaining it at 60°C to perform step S102.

[0027] Preferably, the surface conditioning tank is equipped with a second heating device for heating and maintaining the surface conditioning liquid in the tank at 50°C to perform step S106.

[0028] Preferably, the production line further includes a phosphating tank unit, which includes a phosphating tank and a rotary drive mechanism disposed in the phosphating tank. The rotary drive mechanism is used to drive the workpiece to rotate around its central axis in step S107.

[0029] Preferably, the rotary drive mechanism is configured to drive the workpiece to rotate at a speed of 1 revolution every 5 minutes.

[0030] Preferably, the phosphating tank is equipped with a third heating device for heating the phosphating solution in the tank and maintaining it at 90°C to perform step S107.

[0031] Preferably, the production line is further equipped with a spraying device for spraying and cleaning the workpiece when it exits the tank in steps S102, S106, and S107. Spraying and cleaning can promptly remove the tank liquid adhering to the surface of the workpiece when it exits the tank, avoid cross-contamination between tank liquids, and improve the independence of each process.

[0032] Preferably, the pure water tank used to perform step S105 is configured to allow the tooling to be moved and the flow direction to be switched therein, so as to optimize cleaning dead corners, improve cleaning efficiency and adapt to the compact layout of the production line.

[0033] Preferably, the production line is further equipped with a suction system, which includes a waste gas treatment device, a main suction duct, and multiple suction points. The main suction duct is located at the top of the main frame, with one end connected to and communicating with each suction point, and the other end connected to and communicating with the waste gas treatment device. The suction system promptly removes acid mist, alkaline mist, and hot steam generated in each treatment tank, improving the working environment.

[0034] Preferably, the production line is further equipped with an electrical control system, which is signal-connected to the automatic transfer components, various heating devices, gas bubbling devices, rotary drive mechanisms, spraying devices, and suction systems. The electrical control system is configured to automatically control the operation of each actuator according to preset process parameters.

[0035] Compared with the prior art, the present invention has the following beneficial effects: 1. High degree of automation and significantly improved production efficiency. Automatic transfer components such as gantry robotic arms enable the automatic flow of workpieces between processes, while a PLC control system precisely executes each technological step, replacing traditional manual operation. The entire process can achieve continuous and batch operations, greatly improving production efficiency and capacity.

[0036] 2. Stable and reliable processing quality with excellent product consistency. By precisely controlling the temperature (60℃ for degreasing, 50℃ for surface conditioning, and 90℃ for phosphating) and processing time in key steps such as degreasing, surface conditioning, and phosphating, a high degree of repeatability of process conditions is ensured. In particular, the slow rotation of the workpiece around its central axis during phosphating (one revolution every 5 minutes) guarantees uniform coverage of the phosphating film in the inner holes of the bearing cage and complex surface areas, avoiding the uneven film layer problems caused by air bubble retention or solution concentration gradients in traditional static phosphating methods.

[0037] 3. The solutions are mixed evenly, ensuring a thorough chemical reaction. Gas bubbling devices are installed in the degreasing and surface conditioning tanks. The agitation of the bubbles ensures uniform concentration and temperature distribution of the solutions, guaranteeing a complete chemical reaction during degreasing and surface conditioning, thus improving treatment effectiveness and efficiency.

[0038] 4. The process is rationally connected to avoid cross-contamination. Pure water rinsing effectively isolates each process, preventing cross-contamination of the tank solutions; the spray system provides immediate cleaning of the workpieces upon removal from the tank, further reducing tank solution entrainment; the treatment tanks are arranged in an orderly manner, ensuring a smooth process flow and guaranteeing the independence and effectiveness of each processing step. Attached Figure Description

[0039] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the production line of the present invention; Figure 2 This is a process flow diagram of the present invention.

[0040] In the diagram: 1. Main frame; 2. Tooling loading unit; 3. Isolation group; 4. Phosphating tank unit; 5. Liquid storage tank unit; 6. Automatic transfer assembly. Detailed Implementation

[0041] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0042] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0043] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0044] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0046] Example 1 like Figure 1-2 As shown, this embodiment uses a standard bearing cage (outer diameter approximately 200 mm, height approximately 50 mm) as the processing object to describe in detail the phosphating process using the production line of this invention.

[0047] After the bearing cage workpieces pass the incoming material inspection, the operators sequentially mount them onto the special hangers in the tooling loading unit. Each hanger is designed with a multi-layer structure, with 6 workpieces hanging side by side on each layer, for a total of 4 layers, and a single batch loading capacity of 24 workpieces. After the tooling loading is completed, the automatic operation program of the production line is started.

[0048] The gantry robotic arm system operates automatically according to a preset process sequence under PLC control. First, the gantry robotic arm grips the fixture loaded with workpieces and transfers it to the degreasing tank. The degreasing tank contains a pre-prepared 5% concentration of a special degreasing agent aqueous solution. The first heating device heats the degreasing solution to 60°C and maintains a constant temperature. After the workpiece is immersed in the degreasing solution, a gas bubbling device at the bottom of the tank continuously introduces compressed air into the tank, generating a uniform bubble flow to thoroughly stir and mix the degreasing solution. The degreasing treatment time is 8 minutes. During this time, the agitation of the bubbles ensures full contact between the degreasing solution and the workpiece surface, effectively removing rust-preventive oil, lubricating oil, and residual machining oil from the workpiece surface.

[0049] After degreasing is completed, the gantry robotic arm removes the fixture from the degreasing tank. As the workpiece exits the tank, the spraying device automatically starts, spraying pure water onto the workpiece surface to remove the degreasing solution adhering to the surface. Subsequently, the robotic arm transfers the fixture to the first pure water tank for immersion cleaning, which takes 3 minutes.

[0050] After the first cleaning, the tooling is transferred to the pickling tank. The pickling solution is an 8% hydrochloric acid solution, and the workpiece is immersed for 5 minutes at room temperature to remove oxide scale and rust from the surface and activate the metal surface.

[0051] After pickling, the tooling is sequentially rinsed by an exit spray and then immersed in a second pure water tank (rinsing time 3 minutes) to thoroughly remove residual acid. Subsequently, the tooling is transferred to a surface conditioning tank. The surface conditioning tank contains a pre-prepared 0.15% aqueous solution of a special surface conditioning agent, and a second heating device heats the solution to 50°C and maintains a constant temperature. After the workpiece is immersed in the surface conditioning solution, a gas bubbling device is activated, using bubbles to agitate and uniformly mix the solution. The surface conditioning treatment lasts for 2 minutes, forming a uniform, refined crystal nucleus layer on the workpiece surface, providing a good crystallization basis for subsequent phosphating.

[0052] After surface conditioning, the fixture is transferred to the phosphating tank. The phosphating tank contains a zinc-based phosphating solution, with total acidity controlled at 20-25 points, free acidity controlled at 0.8-1.2 points, and accelerator concentration controlled at 2-3 points. A third heating device heats the phosphating solution to 90℃ and maintains a constant temperature. After the workpiece is immersed in the phosphating solution, the rotary drive mechanism is activated, driving the fixture to slowly rotate around its central axis at a speed of 1 revolution every 5 minutes. The phosphating treatment time is 12 minutes. During rotation, the phosphating solution evenly covers all surfaces of the workpiece, including complex geometric areas such as the inner holes and window holes of the bearing cage, ensuring a uniform phosphating film thickness and fine crystals. After the phosphating treatment is completed, the spraying device is activated again for spray cleaning when the workpiece is removed from the tank.

[0053] After phosphating, a third cleaning is performed. Following cleaning, the fixture is moved to the air-cutting water removal station, where a high-pressure air knife blows away any residual moisture from the workpiece surface. Next, the fixture enters the rust-preventive oil coating station, where rust-preventive oil is applied by spraying for 3 minutes. Finally, the gantry robot arm moves the fixture to the unloading station, where operators unload the processed workpieces from the hanger, completing the batch processing. The total processing time for a single batch is approximately 45 minutes, with the phosphating film thickness controlled within the range of 8-15 μm. The film layer is uniform and fine, without any exposed substrate or mottling.

[0054] Example 2 This embodiment uses a large bearing cage (outer diameter approximately 400mm, height approximately 80mm) as the processing object to illustrate the adaptability of the production line of the present invention when processing large-sized workpieces.

[0055] Due to the large size of the workpieces, each hanger can only hold 2 workpieces per layer, with a total of 3 layers. The loading capacity for a single batch is 6 workpieces. After loading is complete, the production line's automatic operation program is started.

[0056] Degreasing treatment: A 5% concentration of special degreasing agent aqueous solution is heated to 60°C and kept at a constant temperature. Gas bubbling is turned on throughout the process. The treatment time is 10 minutes (2 minutes longer than in Example 1, to accommodate large workpieces with a lot of oil on their surface).

[0057] After degreasing, the workpiece is sprayed out of the tank and rinsed with pure water for the first time (4 minutes), followed by pickling. The pickling solution is a 10% hydrochloric acid solution, and the workpiece is immersed at room temperature for 7 minutes (2 minutes longer than in Example 1 to ensure complete removal of oxide scale from the surface of large workpieces).

[0058] After pickling, the workpiece is sprayed after exiting the tank and rinsed a second time with pure water (rinsing time 4 minutes), followed by surface conditioning treatment. The surface conditioning solution is a 0.15% aqueous solution of a special surface conditioning agent, heated to 50°C and kept at a constant temperature, with gas bubbling running throughout the process, and the treatment time is 3 minutes (1 minute longer than in Example 1, to ensure that the surface of large workpieces is completely covered with the surface conditioning layer).

[0059] After surface conditioning, phosphating is performed. The phosphating solution parameters are the same as in Example 1, heated to 90°C and kept at a constant temperature. After the workpiece is immersed in the phosphating solution, the rotary drive mechanism drives the fixture to rotate slowly at a speed of 1 revolution every 5 minutes. Due to the large size of the workpiece, the phosphating treatment time is extended to 18 minutes to ensure that the phosphating solution fully penetrates all surface areas of the workpiece and forms a uniform and fine phosphating film.

[0060] After phosphating, the workpiece undergoes a third pure water rinse following a spray cleaning process. This is followed by air-cutting and water removal treatment, with the high-pressure air knife blowing time extended to 3 minutes (2 minutes in Example 1) to ensure complete removal of moisture from the surface of large workpieces. Finally, an anti-rust oil spray coating is applied for 3 minutes.

[0061] Testing revealed that the phosphate film thickness on the surface of the large bearing cage treated in this embodiment was 10-18 μm. The film was uniform, dense, and completely covered, without any exposed substrate, spots, or flow marks, meeting the phosphate quality requirements for large bearing cages. This embodiment verifies the good adaptability of the production line of this invention to bearing cages of different specifications.

[0062] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0063] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0064] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A reciprocating phosphating process and production line for bearing cages, characterized in that, This production line is used to perform an automated phosphating process, the process comprising the following steps: S101: Load the bearing cage workpiece to be processed into the tooling via the tooling loading unit; S102: The workpiece loading device is placed in a degreasing liquid for degreasing treatment by an automatic transfer component, and the degreasing liquid is uniformly mixed by gas bubbling; S103: Immerse the degreased workpiece in pure water for the first cleaning; S104: Immerse the workpiece after the first cleaning in the pickling solution for pickling treatment. S105: Immerse the pickled workpiece in pure water for a second cleaning; S106: The workpiece after the second cleaning is immersed in the surface conditioning solution for surface conditioning treatment, and the surface conditioning solution is uniformly mixed by gas bubbling. S107: Immerse the surface-conditioning treated workpiece in a phosphating solution for phosphating treatment, and control the workpiece to rotate around its central axis. S108: Immerse the phosphated workpiece in pure water for a third cleaning; S109: After phosphating, the workpiece is dewatered by air and coated with anti-rust oil; S110: Remove the workpiece that has undergone rust prevention treatment from the tooling.

2. The bearing cage reciprocating phosphating production line according to claim 1, characterized in that, The automatic transfer component is a gantry robotic arm system, used to realize the automatic transfer of workpieces between various processing units on the main frame.

3. The bearing cage reciprocating phosphating production line according to claim 1, characterized in that, The production line also includes a liquid storage tank unit, which includes a degreasing tank and a surface conditioning tank. Both the degreasing tank and the surface conditioning tank are equipped with gas bubbling devices to perform the gas bubbling and mixing operations in steps S102 and S106.

4. The bearing cage reciprocating phosphating production line according to claim 3, characterized in that, The degreasing tank is equipped with a first heating device for heating the degreasing liquid in the tank and maintaining it at 60°C to perform step S102.

5. The bearing cage reciprocating phosphating production line according to claim 3, characterized in that, The surface conditioning tank is equipped with a second heating device for heating and maintaining the surface conditioning liquid in the tank at 50°C to execute step S106.

6. The bearing cage reciprocating phosphating production line according to claim 1, characterized in that, The production line also includes a phosphating tank unit, which includes a phosphating tank and a rotary drive mechanism disposed in the phosphating tank. The rotary drive mechanism is used to drive the workpiece to rotate around its central axis in step S107.

7. The bearing cage reciprocating phosphating production line according to claim 6, characterized in that, The rotary drive mechanism is configured to drive the workpiece to rotate at a speed of 1 revolution every 5 minutes.

8. The bearing cage reciprocating phosphating production line according to claim 6, characterized in that, The phosphating tank is equipped with a third heating device for heating the phosphating solution in the tank and maintaining it at 90°C to execute step S107.

9. The bearing cage reciprocating phosphating production line according to claim 1, characterized in that, The production line is also equipped with a spraying device for preliminary spraying and cleaning of the workpiece when it leaves the tank in steps S102, S106 and S107.

10. The bearing cage reciprocating phosphating production line according to claim 1, characterized in that, The pure water tank used to perform step S105 is configured to allow the tooling to be moved and the flow direction to be switched therein.

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