A centrifugal casting device and method for bimetallic bushings based on a lathe

Abstract

A lathe-based bimetallic bushing centrifugal casting device and method, comprising a lathe bed, one end of the lathe bed is provided with a main shaft driving assembly, the other end is provided with an axial hollow tailstock assembly, the main shaft driving assembly and the tailstock assembly are connected in series with a hydraulic tensioning rotary tool assembly at the tail, the hydraulic tensioning rotary tool assembly rotates and seals the whole circle pipe formed by the mutual embracing of two semicircular bushings, the hydraulic tensioning rotary tool assembly is connected with the main shaft driving assembly and the tailstock assembly, the axial hollow structure of the tailstock assembly is matched with a movable casting device, the casting trolley of the movable casting device sends molten copper alloy into the inner wall of the whole circle pipe, the whole circle pipe rotates under the driving of the main shaft driving assembly, the copper alloy liquid is centrifugally cast on the inner wall of the heated whole circle pipe, and after cooling, the two semicircular bushings are separated, and the centrifugal casting of the bimetallic bushing is completed. The present application improves the metallurgical engagement ability of the bimetallic bushing by centrifugal casting of copper alloy under high temperature.

Description

Technical Field

[0001] This application relates to the field of bimetallic bearing manufacturing technology, and more specifically, to a lathe-based centrifugal casting apparatus and method for bimetallic bearings. Background Technology

[0002] Bimetallic bearings, as core components in heavy-duty transmission systems such as internal combustion engines, gearboxes, and hydraulic machinery, typically employ iron or steel as the base material to provide necessary strength and rigidity. Simultaneously, a wear-resistant layer of copper alloy or Babbitt alloy is formed on the inner surface of the base material through a composite process to leverage its advantages in friction reduction, wear resistance, and thermal conductivity. This bimetallic structure, through the complementary properties of materials, significantly improves the service life and operational stability of the bearing under high load and high temperature conditions, leading to its widespread application in industries such as automotive manufacturing, construction machinery, and shipbuilding. However, because the geometry of bimetallic bearings is not a complete cylinder but a non-circular structure composed of two semi-circular bearings, it presents a fundamental challenge to the manufacturing process. Currently, the industry mainly relies on 3D stacking technology for bimetallic fabrication, but this technology suffers from high manufacturing costs. Furthermore, during the stacking process, the molten metallographic composite ability of the copper wires is weak, easily generating microscopic defects such as bubbles and micropores at the connection interface. These defects can easily lead to cracking of the connection surface or detachment of the wear-resistant layer during subsequent use, seriously affecting product reliability and safety. Furthermore, traditional sintering composite processes, static casting processes, and conventional centrifugal casting processes are all ineffective in adapting to this non-circular structure. Centrifugal casting, in particular, while offering the advantage of uniform molten metal distribution in the manufacture of circular workpieces, suffers from uneven centrifugal force distribution due to the non-circular shape of the bimetallic bearing. This makes it impossible to achieve stable adhesion and uniform fusion of the copper alloy liquid, hindering existing processes from meeting the demands for high-performance, rapid, and low-cost production. Therefore, overcoming shape limitations and developing a highly efficient bimetallic bearing fabrication scheme for non-circular structures has become a critical problem urgently needing to be solved by those skilled in the art. Summary of the Invention

[0003] The purpose of this application is to provide a centrifugal casting device and method for bimetallic bearings based on a lathe, which has the advantages of breaking through the technical bottleneck of centrifugal casting of non-circular structures, avoiding the overflow of molten copper alloy, achieving uniform adhesion and fusion of copper alloy layers, improving product quality and reliability, and reducing production costs.

[0004] This application provides a lathe-based centrifugal casting device for bimetallic bearing bushes, comprising a lathe bed, a spindle drive assembly at one end of the lathe bed, and an axially hollow tailstock assembly at the other end. A hydraulic tensioning rotary fixture assembly is connected end-to-end between the spindle drive assembly and the tailstock assembly. The hydraulic tensioning rotary fixture assembly rotates and seals a circular tube formed by two semi-circular bearing bushes interlocking. The hydraulic tensioning rotary fixture assembly connects the spindle drive assembly and the tailstock assembly. The axially hollow structure of the tailstock assembly is used in conjunction with a movable casting device. The casting carriage of the movable casting device feeds molten copper alloy into the inner wall of the circular tube. A heating coil of an induction heating device is connected to the outer wall of the circular tube. The circular tube rotates under the drive of the spindle drive assembly, centrifugally casting the molten copper alloy onto the heated inner wall of the circular tube. After the circular tube cools, the two semi-circular bearing bushes separate, thus completing the centrifugal casting of the bimetallic bearing bushes. This invention improves the metallographic meshing ability of bimetallic bearing bushes by centrifugally casting copper alloy at high temperatures.

[0005] The lathe bed and the spindle drive assembly are connected by a drive bracket. The drive bracket is equipped with a first drive rod, which drives the spindle drive assembly to move along the slide of the lathe bed. The spindle drive assembly includes a spindle drive motor, which is connected to a drive pulley. The drive pulley is connected to a driven pulley via a belt. The center of the driven pulley is connected to the drive shaft via a pin. The outer circumference of the drive shaft is connected to a cooling water tank via two ball bearings. The cooling water tank is connected to cooling water via a pipe.

[0006] Both ends of the drive shaft extend out of the cooling water tank. One end is connected to the first flange, and the other end is connected to the hydraulic oil pump. The hydraulic oil pump drives the hydraulic tie rod to move back and forth. The drive shaft has a through hollow structure in the axial direction. The hydraulic tie rod passes through the hollow structure and passes through the first flange to connect to the hydraulic tensioning rotary tooling assembly.

[0007] The hydraulic tensioning rotary tooling assembly includes a connecting column, with an expanded second flange and a third flange at each end of the connecting column. The second flange connects to the first flange, and the third flange connects to the first circular tensioning ring. The first circular tensioning ring connects to one end of the full-circle tube, and the other end of the full-circle tube connects to the second circular tensioning ring, which connects to the tailstock assembly. Both the first and second circular tensioning rings have tensioning ramps at their connection ends with the full-circle tube. The two tensioning ramps are arranged in opposite directions relative to the full-circle tube. When the full-circle tube is subjected to axial force, the two tensioning ramps radially press the two semi-circular bearings together to prevent molten copper alloy from overflowing.

[0008] The hydraulic tie rod is sequentially connected to the drive shaft, the first axial inner hole of the connecting column, and the second inner hole at the center of the first circular tensioning ring on its outer periphery. The outer end of the hydraulic tie rod is fastened to the second inner hole.

[0009] The tailstock assembly includes a tailstock housing, which is provided with a fourth flange that connects to a second circular tensioning ring. The fourth flange is integrally formed and connected to a bushing. The inner hole of the bushing is connected to the center hole of the second circular tensioning ring. The outer circumference of the bushing is fitted with a second ball bearing installed inside the tailstock housing. A second cooling water pipe is provided on the side of the tailstock housing, and the second cooling water pipe outputs cooling water to cool the second ball bearing and the bushing.

[0010] The outer circumference of the circular tube is fitted with a cooling water nozzle, which is connected to a cold water control pipe.

[0011] The mobile casting device includes a guide rail connected to the lathe bed, a sliding trolley connected to the guide rail, and a casting trolley movably connected to the sliding trolley.

[0012] The hydraulic tensioning rotary tooling assembly is provided with a protective cover on its outer periphery, and the protective cover is connected to a second drive rod.

[0013] A centrifugal casting method for bimetallic bearings based on a lathe includes the following steps:

[0014] Step 1: Connect one end of the two semi-circular bearing bushes that interlock to form a complete circular tube to the second circular tensioning ring;

[0015] Step 2: Fit the heating coil of the induction heating device onto the outer circumference of the round tube;

[0016] Step 3: The first drive rod drives the main shaft drive assembly to move axially along the drive shaft and approach the whole circular tube until the whole circular tube abuts against the first circular tensioning ring.

[0017] Step 4: Drive the hydraulic tensioning rotary tooling assembly. The hydraulic tie rod drives the first circular tensioning ring to move axially, so that the first circular tensioning ring and the second circular tensioning ring use two tensioning ramps to tension the whole circular tube in opposite directions.

[0018] Step 5: Start the spindle drive motor to make the drive shaft rotate the whole round tube, and at the same time heat the whole round tube to the set temperature through the heating coil;

[0019] Step Six: Add the molten copper alloy liquid to the casting carriage. The casting carriage is driven by the sliding carriage through the guide rail to feed the molten copper alloy liquid into the inner wall of the round tube through the inner hole of the bushing of the tailstock assembly. The rotating inner wall of the round tube uses centrifugal force to attach and fuse the copper alloy liquid to the inner wall of the round tube. According to the input copper alloy liquid volume, the set fusion thickness is reached. After cooling by the cooling water output from the cooling water nozzle, the two semi-circular bearings are cut and separated to obtain the bimetallic bearing.

[0020] As described above, the centrifugal casting device for bimetallic bearing bushes based on a lathe provided in this application includes a lathe bed. One end of the lathe bed is equipped with a spindle drive assembly, and the other end is equipped with an axially hollow tailstock assembly. A hydraulic tensioning rotary tooling assembly is connected end-to-end between the spindle drive assembly and the tailstock assembly. The hydraulic tensioning rotary tooling assembly includes a tooling device for rotating and sealing a complete circular tube formed by the mutual engagement of two semi-circular bearing bushes. The hydraulic tensioning rotary tooling assembly connects the spindle drive assembly and the tailstock assembly. The axially hollow structure of the tailstock assembly cooperates with a mobile casting device. The casting carriage of the mobile casting device feeds molten copper alloy into the complete circular tube. The outer wall of the round tube is fitted with a heating coil of an induction heating device. Driven by the main shaft drive assembly, the round tube rotates and centrifugally pours copper alloy liquid onto the heated inner wall of the round tube. After the round tube cools, the two semi-circular bearings are separated to complete the centrifugal casting of the bimetallic bearing. The dynamic sealing and rotation of the non-round structure are achieved by the hydraulic tensioning rotating tooling assembly. The combination of centrifugal force and induction heating effectively solves the problem of uneven casting caused by the non-round structure of the bimetallic bearing, as well as the problem of metal bonding density caused by temperature difference. It has significant advantages in breaking through shape limitations, avoiding micro-defects, improving product performance and production efficiency. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings:

[0022] Figure 1 This is a schematic diagram of the main structure of a centrifugal casting device for bimetallic bearings based on a lathe according to the present invention;

[0023] Figure 2 This is a schematic diagram of the main spindle drive assembly structure in this invention.

[0024] Figure 3 This is a schematic diagram of the hydraulic tensioning rotary tooling assembly in this invention;

[0025] Figure 4 This is a schematic diagram of the exploded installation structure of the hydraulic tensioning rotary tooling assembly in this invention;

[0026] Figure 5 This is a schematic diagram of the heating coil structure of the heating device in the present invention under operating conditions;

[0027] Figure 6 This is a side view of the tailstock assembly in this invention.

[0028] Figure 7 This is a cross-sectional view of the tailstock assembly in this invention. Detailed Implementation

[0029] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0030] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] Traditional bimetallic bearing manufacturing processes, due to their non-circular shape, primarily rely on 3D stacking technology. This results in high manufacturing costs, weak metallographic composite ability of the molten copper wires during stacking, and a tendency for bubbles or micropores to form at the joint surface, leading to breakage and detachment. Furthermore, mainstream sintering composite processes, static casting processes, and traditional centrifugal casting processes are not effectively adapted to the non-circular shape of the bearings, making it difficult to achieve high-performance, rapid, and low-cost bimetallic bearing manufacturing.

[0032] In response, this application proposes a centrifugal casting device for bimetallic bearing bushes based on a lathe, including a lathe bed. One end of the lathe bed is equipped with a spindle drive assembly, and the other end is equipped with an axially hollow tailstock assembly. The spindle drive assembly and the tailstock assembly are connected end-to-end to a hydraulic tensioning rotary tooling assembly. The hydraulic tensioning rotary tooling assembly rotates and seals the whole circular tube formed by the mutual clamping of two semi-circular bearing bushes 11. The hydraulic tensioning rotary tooling assembly is connected to the spindle drive assembly and the tailstock assembly. The axially hollow structure of the tailstock assembly is used in conjunction with a mobile casting device. The casting carriage 7 of the mobile casting device feeds molten copper alloy into the inner wall of the whole circular tube. The outer wall of the whole circular tube is equipped with the heating coil 22 of the induction heating device 21. The whole circular tube rotates under the drive of the spindle drive assembly, centrifugally casting the molten copper alloy onto the heated inner wall of the whole circular tube. After the whole circular tube is cooled, the two semi-circular bearing bushes 11 are separated to complete the centrifugal casting of the bimetallic bearing bushes.

[0033] For ease of understanding, the following explains some key terms in this embodiment:

[0034] Lathe bed: As the basic support structure of the entire device, it is used to install and fix the spindle drive assembly, tailstock assembly and other related components, and provides motion guides.

[0035] Spindle drive assembly: responsible for providing rotational power to drive the tooling device and the whole round tube to rotate at high speed to realize the centrifugal casting process.

[0036] Tailstock assembly: Located at the other end of the lathe bed, opposite to the spindle drive assembly, it supports the other end of the tooling device and has an axially hollow structure to facilitate the introduction of casting material.

[0037] The hydraulic tensioning rotary tooling assembly is the core component for achieving the engagement, rotation, and sealing of the semi-circular bearing bushes. Its internal structure can tightly engage two semi-circular bearing bushes 11 to form a complete circular tube and ensure that the seal is maintained during high-speed rotation and high-temperature casting.

[0038] Semi-circular bearing 11: This is the base part that constitutes the bimetallic bearing. It is usually made of steel or iron and is bound together in this device to form a complete circular tube as a casting mold.

[0039] The complete circular tube is formed by two semi-circular bearing bushes 11 that interlock, serving as the inner mold for centrifugal casting. Its inner wall will be bonded with molten copper alloy to form a wear-resistant layer.

[0040] Mobile casting device: used to precisely and stably deliver molten copper alloy liquid into the inner wall of a rotating circular tube.

[0041] Casting trolley 7: This is part of the mobile casting device, which carries and transports molten copper alloy liquid.

[0042] Induction heating device 21: Heats the entire circular tube through the principle of electromagnetic induction to ensure that the copper alloy liquid can be well fused with the inner wall of the entire circular tube.

[0043] Heating coil 22: It is the core component of induction heating device 21. It generates an alternating magnetic field, which causes eddy currents in the entire circular tube to generate heat.

[0044] Centrifugal casting: a casting method that uses centrifugal force to spread and solidify molten metal evenly on the inner wall of a rotating mold, which helps to form a dense, defect-free composite layer.

[0045] This embodiment provides a lathe-based centrifugal casting device for bimetallic bearings. The device includes a lathe bed, which serves as the base for the entire device and can be made of cast iron or welded steel, providing a stable support platform. A spindle drive assembly is located at one end of the lathe bed, and an axially hollow tailstock assembly is located at the other end. The spindle drive assembly can be directly driven by an electric motor via a gearbox or belt drive mechanism to rotate the spindle, providing the required rotational speed for the entire circular tube. The tailstock assembly can be a fixed or movable support base with a through-hole for introducing subsequent casting material.

[0046] A hydraulic tensioning rotary tooling assembly connects the main spindle drive assembly and the tailstock assembly. This hydraulic tensioning rotary tooling assembly is the core component of this device, and its function is to rotate and seal the two semi-circular bearing shells 11 that interlock to form a complete circular tube. Specifically, the tooling device can consist of a set of mechanical clamps that tightly clamp the two semi-circular bearing shells 11 into a complete circular tubular structure using bolts or wedges, ensuring that there is no loosening or leakage during rotation. This tooling device is connected to the main spindle drive assembly and the tailstock assembly via a coupling or flange to transmit rotational power and maintain axial alignment.

[0047] The axially hollow structure of the tailstock assembly mates with a movable casting device. The hollow structure of the tailstock assembly can be a simple cylindrical channel allowing casting material to pass through. The movable casting device can be a simple trolley with a hopper and outlet, moved along the lathe bed by manual pushing or a simple guiding mechanism. The casting trolley 7 of this movable casting device feeds molten copper alloy into the inner wall of the circular tube. The casting trolley 7 can be a crucible with a tilting mechanism, pouring the molten copper alloy liquid into the interior of the circular tube by gravity.

[0048] The outer wall of the circular tube is fitted with a heating coil 22 of an induction heating device 21. The heating coil 22 can be a copper coil that surrounds the outside of the circular tube. It generates induction heat through high-frequency current to preheat the circular tube to above the melting point of the copper alloy. The circular tube rotates under the drive of the spindle drive assembly, which drives the tooling device and the circular tube to rotate at a preset speed through its internal transmission mechanism.

[0049] After the circular tube rotates and is heated to a set temperature, molten copper alloy is fed into the inner wall of the tube through a casting carriage 7. Under centrifugal force, the molten copper alloy spreads evenly and adheres tightly to the heated inner wall of the circular tube, forming a dense composite layer. After casting, the circular tube can be cooled naturally or by external air cooling. Once cooled, the two semi-circular bearing shells 11 are removed from the tooling device and separated by mechanical cutting or separation methods to obtain the bimetallic bearing shell.

[0050] The lathe-based centrifugal casting apparatus for bimetallic bearings proposed in this embodiment effectively solves the problems of high cost, weak metallographic composite capability, and susceptibility to defects associated with traditional 3D stacking techniques by combining semi-circular bearing shells with a fully circular tube and utilizing the rotational function of the lathe with centrifugal casting technology. This apparatus enables tight fusion of the copper alloy liquid with the bearing shell substrate, forming a dense and bubble-free composite layer, thereby improving the bonding strength and performance of the bimetallic bearing. Furthermore, this method is adaptable to non-circular bearing shapes, providing a high-performance, rapid, and low-cost route for manufacturing bimetallic bearings.

[0051] In some embodiments described above in this application, the spindle drive assembly is responsible for driving the rotation of the full-circular tube, and its working accuracy and stability are crucial to the casting quality. However, if the connection and driving method between the spindle drive assembly and the lathe bed are not precise enough, or if the heat dissipation problem of its internal components is not effectively solved, the spindle drive assembly may experience displacement or overheating during operation, thereby affecting the rotation accuracy of the full-circular tube and the service life of the equipment, and ultimately affecting the casting quality of the bimetallic bearing.

[0052] In response, this application further proposes a centrifugal casting device for bimetallic bearings based on a lathe. The lathe bed and the spindle drive assembly are connected via a drive bracket 4. The drive bracket 4 is equipped with a first drive rod 2, which drives the spindle drive assembly to move along a slider 25 on the lathe bed. The spindle drive assembly includes a spindle drive motor 1, which is connected to a drive pulley 16. The drive pulley 16 is connected to a driven pulley 161 via a belt 162. The center of the driven pulley 161 is connected to a drive shaft 36 via a pin. The outer circumference of the drive shaft 36 is connected to a cooling water tank 12 via two ball bearings 17. The cooling water tank 12 is connected to cooling water via pipes.

[0053] Specifically, the drive bracket 4, acting as a structural bridge between the lathe bed and the spindle drive assembly, primarily provides stable support and connection, ensuring the spindle drive assembly is securely mounted on the lathe bed and can withstand various forces and torques generated during operation. The drive bracket 4 is typically manufactured from high-strength cast iron or welded steel structural components to guarantee sufficient rigidity and stability. Its connection to the lathe bed and spindle drive assembly can be achieved through bolt fastening, pin positioning, or other methods, ensuring reliable and removable connections.

[0054] The first drive rod 2 is a key actuator that enables the spindle drive assembly to move axially along the lathe bed. It transmits external driving force to the spindle drive assembly, allowing it to perform precise positioning and adjustment. The first drive rod 2 can be a lead screw, rack and pinion, or piston rod of a hydraulic cylinder. For example, when a lead screw is used, one end of the lead screw is fixedly connected to the drive bracket 4, and the other end is connected to the spindle drive assembly via a nut. Rotating the lead screw achieves axial movement of the spindle drive assembly.

[0055] The slider 25 is a guide component on the lathe bed used to guide the spindle drive assembly in linear motion. It cooperates with the guide rails on the lathe bed to ensure that the spindle drive assembly maintains a precise linear trajectory during movement, avoiding skewing or jamming, thus guaranteeing alignment accuracy during centrifugal casting. The slider 25 is typically part of a high-precision linear guide system, including the guide rail and the slider. The guide rail is fixed to the lathe bed, while the slider is mounted on the bottom of the spindle drive assembly or its drive bracket 4. The slider 25 typically contains balls or rollers to reduce frictional resistance and improve the smoothness and accuracy of the movement.

[0056] The spindle drive motor 1 is the core component that provides rotational power for the entire centrifugal casting process. It converts electrical energy into mechanical energy, drives the subsequent transmission mechanism, and ultimately makes the entire circular tube rotate at high speed to achieve centrifugal casting of copper alloy liquid. The spindle drive motor 1 is usually an AC servo motor or a frequency converter motor to achieve a wide range of speed adjustment and precise speed control.

[0057] The drive pulley 16 is the first transmission component that outputs power from the spindle drive motor 1. It transmits the high-speed rotational motion of the motor to the belt 162, thereby starting the entire belt drive system. The drive pulley 16 is usually fixed to the output shaft of the spindle drive motor 1 by a key connection or an expansion sleeve connection.

[0058] The belt 162 and the driven pulley 161 constitute a belt drive system for transmitting power from the main shaft drive motor 1 to the drive shaft 36, and potentially enabling speed changes. The belt 162 is typically a V-belt, synchronous belt, or multi-ribbed belt, selected based on the required transmission power, speed ratio, and space constraints. The driven pulley 161 is fixed to the drive shaft 36 via a key connection or an expansion sleeve connection.

[0059] The pin here serves to ensure a reliable connection between the driven pulley 161 and the drive shaft 36, guaranteeing that the rotational motion of the driven pulley 161 can be accurately transmitted to the drive shaft 36. The pin is typically a cylindrical pin or a tapered pin, and is connected to the drive pulley 161 and the drive shaft 36 through an interference fit or clearance fit, supplemented by fasteners.

[0060] The drive shaft 36 is the core of the entire rotating system, directly driving the rotation of the hydraulic tensioning rotating tooling assembly and the entire circular tube. The ball bearing 17 supports the drive shaft 36, enabling it to rotate smoothly and with low friction, and withstand radial and axial loads. The cooling water tank 12 connects to the ball bearing 17, designed to effectively dissipate heat generated by the bearing and drive shaft during high-speed rotation, preventing overheating and thus ensuring bearing life and rotational accuracy. The ball bearing 17 is typically a deep groove ball bearing or an angular contact ball bearing, offering high rotational accuracy and load-bearing capacity. The cooling water tank 12 can be an annular cavity surrounding the outer ring or bearing housing of the ball bearing 17, filled with cooling water.

[0061] The cooling water tank 12 is connected to an external cooling water system via pipes, forming a closed or open cooling loop. This continuously provides low-temperature cooling water to the cooling water tank 12 and discharges or returns the high-temperature water that has absorbed heat to the cooling tower for further cooling. The pipes are typically made of corrosion-resistant and pressure-resistant metal pipes or high-pressure rubber hoses.

[0062] Through the above technical solution, the drive bracket 4 provides a stable connection foundation for the lathe bed and the spindle drive assembly, ensuring the structural stability of the spindle drive assembly. The cooperation between the first drive rod 2 and the slider 25 enables the spindle drive assembly to move precisely and smoothly along the lathe bed, thereby facilitating the installation and adjustment of the hydraulic tensioning rotary tooling assembly and its alignment with the tailstock assembly, ensuring the coaxiality of the round tube during centrifugal casting. The spindle drive motor 1 smoothly transmits power to the drive shaft 36 through a belt transmission system (drive pulley 16, belt 162, driven pulley 161), realizing the reliable rotation of the round tube. More importantly, the drive shaft 36 is supported by two ball bearings 17 and connected to the cooling water tank 12, which is connected to cooling water through pipes, forming an effective cooling circuit. This design allows the heat generated by the ball bearing 17 and the drive shaft 36 to be dissipated in a timely manner during high-speed, long-term operation of the spindle drive assembly. This effectively prevents overheating of the bearings, which could lead to decreased precision, accelerated wear, or even damage. Consequently, it ensures the long-term stable operation and rotational accuracy of the spindle drive assembly, thereby improving the casting quality of the bimetallic bearing bush and the service life of the equipment. This structural design not only enhances the operational reliability of the device but also facilitates subsequent maintenance and adjustments.

[0063] In some embodiments described above, a method is proposed to drive the entire circular tube to rotate via a spindle drive assembly and to cool the drive shaft 36 using a cooling water tank 12 to achieve centrifugal casting. However, in actual operation, how to effectively integrate the hydraulic tensioning rotary tooling assembly with the rotating drive shaft 36, and ensure that the hydraulic tensioning mechanism can reliably drive the tensioning action while maintaining the normal rotation and cooling of the drive shaft 36, is a technical problem that needs to be solved. Especially in scenarios where axial tensioning of the entire circular tube is required to prevent molten copper alloy from overflowing, traditional external drive methods may struggle to achieve precise and stable tensioning force transmission.

[0064] In this regard, this application further proposes that both ends of the aforementioned drive shaft 36 extend out of the cooling water tank 12, with one end connected to the first flange 15 and the other end connected to the hydraulic oil pump 13. The hydraulic oil pump 13 drives the hydraulic tie rod 18 to move back and forth. The aforementioned drive shaft 36 has an axial through-hole structure, with the hydraulic tie rod 18 passing through the hollow structure. The hydraulic tie rod 18 also passes through the first flange 15 and connects to the hydraulic tensioning rotary tooling assembly.

[0065] Specifically, the drive shaft 36, as the core component for transmitting rotational power, extends out of the cooling water tank 12 at both ends, designed to provide the necessary space interfaces for subsequent mechanical connections and functional expansion. This design ensures that the drive shaft 36 is adequately cooled inside the cooling water tank 12, while its ends can still be used to connect other key components, thereby achieving more complex functional integration. The length of the drive shaft 36 and the size of the cooling water tank 12 must be precisely matched to ensure that the length of the extended portion is sufficient to install components such as flanges and hydraulic pumps, without affecting the cooling effect.

[0066] The first flange 15 serves as the mechanical connection interface between the drive shaft 36 and the hydraulic tensioning rotary tooling assembly. It provides a robust and precise mounting base for transmitting rotational power and axial tensioning force from the drive shaft 36 to the hydraulic tensioning rotary tooling assembly. The flange connection offers excellent concentricity and rigidity, ensuring stability during rotation and effective transmission of tensioning force. The first flange 15 can be securely fixed to one end of the drive shaft 36 via key connections, bolt connections, or interference fits, ensuring no relative slippage or loosening occurs during high-speed rotation and axial loading.

[0067] The hydraulic pump 13 is the core component providing hydraulic power. It is connected to the other end of the drive shaft 36 and is designed to provide driving force for the hydraulic tensioning rotary tooling assembly. Through the hydraulic pump 13, mechanical energy is converted into hydraulic energy, which in turn drives the hydraulic tie rod 18 to perform precise axial movement, achieving the tensioning operation of the entire circular tube. This integrated approach allows the hydraulic tensioning system to rotate synchronously with the drive shaft 36, simplifying the power transmission path.

[0068] The hydraulic tie rod 18 is the actuator in the hydraulic tensioning rotary tooling assembly. Its back-and-forth movement directly achieves the tensioning and loosening of the entire circular tube. The hydraulic pressure generated by the hydraulic pump 13 acts on the hydraulic tie rod 18 through the hydraulic pipeline, causing it to perform precise reciprocating motion within the axial hollow structure of the drive shaft 36. This hydraulic drive method can provide a large tensioning force and achieve precise control of the tensioning force. The hydraulic tie rod 18 is usually driven by a hydraulic cylinder, and the piston rod of the hydraulic cylinder is the hydraulic tie rod 18. The hydraulic pump 13 supplies or discharges oil to the hydraulic cylinder through a control valve, thereby controlling the extension and retraction of the hydraulic tie rod 18.

[0069] The drive shaft 36 employs an axially through-hole hollow structure, a key design feature for realizing the internal hydraulic tensioning mechanism. This hollow design provides an internal channel for the hydraulic tie rod 18, allowing it to pass through the drive shaft 36 and transmit the driving force of the hydraulic pump 13 to the distal hydraulic tensioning rotary tooling assembly. The hollow structure, while ensuring sufficient strength for the drive shaft 36, integrates internal functional components, avoiding complex external transmission mechanisms. The drive shaft 36 can be formed into a through-hole hollow structure through drilling, casting, or forging followed by machining. The inner diameter of the hollow portion should be slightly larger than the outer diameter of the hydraulic tie rod 18 to ensure smooth passage and axial movement of the hydraulic tie rod 18, while allowing necessary clearance.

[0070] The hydraulic tie rod 18 passes through the hollow structure of the drive shaft 36, allowing the hydraulic tensioning mechanism to be arranged coaxially with the drive shaft 36. This coaxial design not only saves space and simplifies the structure, but more importantly, it ensures that the hydraulic tie rod 18 maintains stable axial movement when the drive shaft 36 rotates at high speed, avoiding vibration problems caused by eccentricity or imbalance. As the hydraulic tie rod 18 passes through the hollow structure of the drive shaft 36, it can be supported and guided by guide sleeves or bearings to reduce friction and ensure smooth and precise movement.

[0071] After passing through the hollow structure of the drive shaft 36, the hydraulic tie rod 18 further passes through the first flange 15 and finally connects to the hydraulic tensioning rotary tooling assembly. This connection method allows the axial movement of the hydraulic tie rod 18 to directly act on the hydraulic tensioning rotary tooling assembly, thereby realizing the tensioning operation of the entire circular tube. The transition through the first flange 15 ensures a reliable connection and force transmission between the hydraulic tie rod 18 and the hydraulic tensioning rotary tooling assembly. The end of the hydraulic tie rod 18 can be fixedly connected to the corresponding component of the hydraulic tensioning rotary tooling assembly by means of threaded connection, pin connection, or snap-fit ​​connection, ensuring effective force transmission during the tensioning process.

[0072] Through the above technical solution, the hydraulic oil pump 13 is directly connected to one end of the drive shaft 36, and the hydraulic tie rod 18 passes through the through-hole structure of the drive shaft 36 before connecting to the hydraulic tensioning rotary tooling assembly. This effectively solves the technical problem of how to stably and accurately drive the hydraulic tensioning mechanism during the rotation and cooling process of the drive shaft 36. This design enables the hydraulic tensioning system to be coaxially integrated with the drive shaft 36, avoiding the complex transmission chain and the resulting transmission errors and stability problems that may exist in traditional external drive methods. The hydraulic oil pump 13 directly drives the hydraulic tie rod 18, which can provide a stable and controllable axial tensioning force, ensuring that the whole round tube is reliably compressed and sealed during centrifugal casting, thereby effectively preventing the overflow of molten copper alloy and improving casting quality and production efficiency. At the same time, the design of the hollow drive shaft 36 provides an internal channel for the hydraulic tie rod 18 without affecting its rotation and cooling functions, making the entire device structure more compact and easier to operate.

[0073] In some of the embodiments described above in this application, a hydraulic tensioning rotary tooling assembly is proposed to rotate and seal the whole circular tube. However, in the process of its implementation, how to ensure that the whole circular tube can be reliably bound and sealed under the action of high-speed rotation and centrifugal force of molten copper alloy, and effectively prevent the molten copper alloy from overflowing from the gap between the semi-circular bearings 11 or the connection with the tooling, is a technical problem that needs to be solved.

[0074] In this regard, this application further proposes that the hydraulic tensioning rotary tooling assembly includes a connecting column 20, with an enlarged second flange 26 and a third flange 27 respectively at both ends of the connecting column 20. The second flange 26 is connected to the first flange 15, and the third flange 27 is connected to the first circular tensioning ring 28. The first circular tensioning ring 28 is connected to one end of the whole circular tube, and the other end of the whole circular tube is connected to the second circular tensioning ring 23. The second circular tensioning ring 23 is connected to the tailstock assembly. The first circular tensioning ring 28 and the second circular tensioning ring 23 are both provided with tensioning inclined surfaces at the connection ends with the whole circular tube. The two tensioning inclined surfaces are set in opposite directions relative to the whole circular tube. When the whole circular tube is subjected to axial force, the two semi-circular bearings 11 are radially pressed by the two tensioning inclined surfaces to prevent molten copper alloy from overflowing.

[0075] Specifically, the connecting column 20, as a structural connector within the hydraulic tensioning rotary tooling assembly, primarily functions to transmit axial force and connect different tensioning components. The connecting column 20 is typically cylindrical or a rod-like structure with a specific cross-section, and its ends are designed with interfaces or mounting surfaces for connection to the second flange 26 and the third flange 27. Its material must possess sufficient strength and rigidity to withstand the axial load during tensioning and the centrifugal force during rotation.

[0076] The second flange 26 and the third flange 27 are enlarged disc-shaped structures used to connect the connecting post 20 to external components, providing a larger contact area or installation space. The second flange 26 connects to the first flange 15, and the third flange 27 connects to the first circular tension ring 28. They are typically secured to the connecting post 20 by bolts, welding, or other fastening methods. The enlarged diameter design helps to distribute stress and provides stable support and a connection interface for the subsequent tension ring.

[0077] The first circular tensioning ring 28 and the second circular tensioning ring 23 are annular components used to directly connect to both ends of the circular tube, achieving radial tensioning and sealing of the circular tube. The first circular tensioning ring 28 connects to one end of the circular tube, and the second circular tensioning ring 23 connects to the other end of the circular tube. They are typically made of high-strength materials, with an inner diameter matching the outer diameter of the circular tube, and are designed with tensioning ramps.

[0078] The tensioning ramps are inclined structures located at the connection ends of the first circular tensioning ring 28 and the second circular tensioning ring 23 with the full-circular tube. They are used to radially compress the full-circular tube under axial force. The two tensioning ramps are arranged in opposite directions relative to the full-circular tube. When the hydraulic rod 18 applies axial force, the axial force is converted into radial clamping force through these ramps, thereby tightly clamping the two semi-circular bearings 11 together and forming a seal with the tensioning rings. The angle design of the ramps is critical, ensuring that sufficient radial clamping force is provided while avoiding excessive stress concentration or slippage.

[0079] When the entire circular tube is subjected to axial force, the two semi-circular bearing shells 11 are radially pressed together by two tensioning ramps to prevent molten copper alloy from overflowing. This is the core function of the entire tensioning mechanism. When the hydraulic rod 18 drives the first circular tensioning ring 28 to move axially, due to the opposing arrangement of the two tensioning ramps, they work together to press the entire circular tube (i.e., the two semi-circular bearing shells 11 wrapped together) from axial to radial. This radial pressing force not only ensures a tight fit between the semi-circular bearing shells 11 but also forms a reliable seal between them and the tensioning ring.

[0080] Through the above technical solution, the hydraulic tensioning rotary tooling assembly, through the synergistic action of the connecting column 20, the second flange 26, the third flange 27, the first circular tensioning ring 28, and the second circular tensioning ring 23, constructs a highly efficient tensioning structure. In particular, the tensioning ramps provided on the first circular tensioning ring 28 and the second circular tensioning ring 23 can effectively convert axial force into radial clamping force when the entire circular tube is subjected to axial force. This radial clamping force ensures that the two semi-circular bearing bushes 11 are tightly bound together, not only ensuring the structural stability of the entire circular tube, but more importantly, effectively preventing molten copper alloy from overflowing from the joint gaps between the semi-circular bearing bushes 11 and the connection with the tooling during centrifugal casting, thereby guaranteeing casting quality and production safety.

[0081] In some embodiments described above in this application, a hydraulic tensioning rotary tooling assembly driven by a hydraulic tie rod is proposed to tension a full-circular tube. However, in actual operation, during the transmission of axial force, the hydraulic tie rod needs to ensure precise alignment and stable connection with each connecting component to avoid problems such as misalignment, wear, or reduced force transmission efficiency under high-speed rotation and stress conditions. This is crucial for ensuring the uniformity of the tensioning effect and the long-term reliable operation of the device.

[0082] In this regard, this application further proposes that the outer periphery of the hydraulic tie rod 18 is sequentially connected to the drive shaft 36, the axial first inner hole 29 of the connecting column 20, and the second inner hole 30 at the center of the first circular tensioning ring 28, and the outer end of the hydraulic tie rod 18 is fastened to the second inner hole 30.

[0083] This connection method ensures good guidance and support for the hydraulic tie rod 18 throughout the transmission path. Specifically, after being led out from the hydraulic pump 13, the hydraulic tie rod 18 first passes through the axial hollow structure of the drive shaft 36. As a rotating component, the drive shaft 36's hollow structure provides the initial axial channel and support for the hydraulic tie rod 18. Subsequently, the hydraulic tie rod 18 continues to pass through the axial first inner hole 29 of the connecting post 20. The connecting post 20, as an intermediate component connecting the drive shaft 36 and the first circular tensioning ring 28, further guides and positions the hydraulic tie rod 18 through its first inner hole 29. Finally, the hydraulic tie rod 18 reaches the first circular tensioning ring 28 and passes through its central second inner hole 30. This sequential passing and connecting structural design ensures that the hydraulic tie rod 18 maintains good coaxiality within the entire hydraulic tensioning rotary tooling assembly, effectively reducing friction and energy loss that may be caused by eccentricity or wobbling, thereby ensuring the smoothness of the axial movement of the hydraulic tie rod 18.

[0084] The outer end of the hydraulic tie rod 18 is fastened to the second inner hole 30 at the center of the first circular tensioning ring 28. This fastening connection is crucial for accurately transmitting the axial movement of the hydraulic tie rod 18 to the first circular tensioning ring 28. The fastening connection can be achieved in various ways. For example, the outer end of the hydraulic tie rod 18 can be designed with external threads to engage with the internal threads inside the second inner hole 30, and then secured with a lock nut or thread-locking adhesive to prevent loosening. Alternatively, the outer end of the hydraulic tie rod 18 can be connected to the second inner hole 30 via a keyway and key, and secured with an axial clamping nut or retaining ring. Furthermore, a tapered fit with bolts can also be used for fastening. Regardless of the fastening method used, the goal is to ensure that the axial push-pull force of the hydraulic tie rod 18 is transmitted to the first circular tensioning ring 28 without damage or gaps, allowing it to move accurately along the axial direction, thereby achieving reliable tensioning of the entire circular tube.

[0085] Through the above technical solution, a continuous and tight connection path is formed between the hydraulic tie rod 18, the drive shaft 36, the connecting column 20, and the first circular tensioning ring 28. This structural design ensures the precise centering and stable support of the hydraulic tie rod 18 within the entire hydraulic tensioning rotary tooling assembly, effectively preventing any possible skewing or vibration of the hydraulic tie rod 18 during high-speed rotation and axial stress of the drive shaft 36. In particular, the tight connection between the outer end of the hydraulic tie rod 18 and the second inner hole 30 of the first circular tensioning ring 28 establishes a robust and gapless mechanical coupling, enabling the axial push-pull force generated by the hydraulic pump 13 to be efficiently and accurately transmitted to the first circular tensioning ring 28. This not only ensures that the first circular tensioning ring 28 can move axially precisely, thereby achieving uniform and reliable tensioning of the entire circular tube, but also significantly improves the stability and reliability of the entire hydraulic tensioning rotary tooling assembly under dynamic operating conditions, effectively extending the service life of components and ensuring product quality during the centrifugal casting process of the bimetallic bearing.

[0086] In some of the embodiments described above in this application, a centrifugal casting device for bimetallic bearings based on a lathe is proposed. The tailstock assembly is a key component for supporting and guiding molten copper alloy. Its internal rotating parts are prone to overheating due to friction and heat accumulation under long-term high-speed operation and high-temperature environment, which in turn affects the operational stability and service life of the device, and may even cause equipment failure.

[0087] In this regard, this application further proposes a specific structure for the tailstock assembly, which includes a tailstock housing 6. The tailstock housing 6 is provided with a fourth flange 14 that connects to the second circular tension ring 23. The fourth flange 14 is integrally formed and connected to a bushing 35. The inner hole 33 of the bushing 35 communicates with the central hole 31 of the second circular tension ring 23. The outer circumference of the bushing 35 is fitted with a second ball bearing 32 installed inside the tailstock housing 6. A second cooling water pipe 34 is provided on the side of the tailstock housing 6. The second cooling water pipe 34 outputs cooling water to cool the second ball bearing 32 and the bushing 35.

[0088] Specifically, the tailstock housing 6 is the external support structure of the tailstock assembly, typically made of high-strength materials (such as cast iron or steel). It houses and protects the internal mechanical components and provides a connection interface with the lathe bed. Its design must possess sufficient rigidity and stability to withstand the forces and vibrations generated during centrifugal casting. The fourth flange 14 is a connecting component on the tailstock housing 6, providing a secure interface for connecting the second circular tensioning ring 23 in the hydraulic tensioning rotating tooling assembly. This flange is typically fixed to the tailstock housing 6 by bolts or other fastening methods, ensuring that the second circular tensioning ring 23 reliably remains coaxial and stable with the tailstock assembly during tensioning and rotation. The bushing 35 is a hollow cylindrical component integrally formed with the fourth flange 14, meaning that the two are manufactured as a single structure, thereby improving the rigidity and concentricity of the connection and reducing assembly errors. The main function of the bushing 35 is to provide a channel for the transport of molten copper alloy and to serve as support and guide for rotating components. The one-piece molding design helps ensure that the molten copper alloy does not leak during passage and can withstand the stress caused by rotation. The inner hole 33 of the bushing 35 is the channel for the molten copper alloy to enter the circular tube, and its design dimensions and surface finish must ensure smooth flow of the copper alloy. This inner hole 33 communicates with the center hole 31 of the second circular tensioning ring 23, forming a continuous channel, allowing the molten copper alloy transported by the casting carriage 7 to accurately enter the inner wall of the circular tube for centrifugal casting. This continuous design ensures the continuity and effectiveness of the casting process. The second ball bearing 32 is a rotating support component installed inside the tailstock housing 6. Its outer ring is fixed to the tailstock housing 6, and its inner ring is fitted to the outer circumference of the bushing 35. The function of the ball bearing is to support the rotation of the bushing 35 and reduce frictional resistance during rotation, ensuring that the bushing 35 can rotate smoothly and efficiently with the circular tube. Choosing a ball bearing helps to provide a lower coefficient of friction and higher rotational accuracy. The second cooling water pipe 34 is a conduit for transporting cooling water. It is located on the side of the tailstock housing 6 for easy introduction and discharge of cooling water. This cooling water pipe 34 is part of the cooling system and is designed to provide a cooling medium for critical components inside the tailstock assembly. The second cooling water pipe 34 delivers cooling water to the vicinity of the second ball bearing 32 and the bushing 35, removing the heat generated by these components under high-speed rotation and high-temperature conditions through heat exchange.

[0089] Through the above technical solution, the bushing 35 inside the tailstock assembly is integrally formed with the fourth flange 14, enhancing structural rigidity and concentricity, and ensuring the stability and sealing of the molten copper alloy conveying channel. The bushing 35 rotates smoothly within the tailstock housing 6 via the second ball bearing 32, effectively reducing frictional resistance. More importantly, the second cooling water pipe 34 located on the side of the tailstock housing 6 can directly supply cooling water to the second ball bearing 32 and the bushing 35, efficiently removing the heat generated by high-speed rotation and heat conduction from the molten copper alloy. This localized and precise cooling mechanism effectively solves the problem of overheating of key rotating components in the tailstock assembly, significantly extending the service life of the second ball bearing 32 and the bushing 35, maintaining the rotational accuracy and operational stability of the device, thereby ensuring the continuity of the bimetallic bearing centrifugal casting process and product quality.

[0090] In some of the above embodiments, after centrifugal casting, the entire round tube needs to be cooled to solidify the molten copper alloy and facilitate the subsequent separation of the semi-circular bearing. However, if the cooling process lacks effective control, it may result in slow cooling rate and uneven cooling, thereby affecting production efficiency and the final quality of the bimetallic bearing.

[0091] In this regard, this application further proposes that a cooling water nozzle 24 is fitted around the outer circumference of the circular tube. The cooling water nozzle 24 is a device for spraying cooling medium onto the outer surface of the circular tube, its main function being to provide external forced cooling to accelerate the cooling process. The cooling water nozzle 24 can be designed in various forms according to actual needs. For example, it can be a ring nozzle to achieve uniform coverage of the circumference of the circular tube, or an array of multiple independent nozzles arranged along the axial or helical direction of the circular tube to ensure that the cooling water can act comprehensively and uniformly on the outer circumferential surface of the circular tube. Its installation position is carefully designed to ensure that the circular tube can be cooled quickly and effectively after the centrifugal casting process, thereby optimizing the cooling effect.

[0092] Simultaneously, the cooling water nozzle 24 is connected to the cold water control pipe 10. The cold water control pipe 10 is a piping system used to transport cooling water and precisely control its flow rate and pressure. This pipe is typically connected to a stable cooling water source, such as an industrial cooling water circulation system or a pump station with constant pressure water supply capability. To achieve refined management of the cooling process, various control components, such as solenoid valves, proportional regulating valves, and flow meters, can be integrated into the cold water control pipe 10. These components work together to precisely adjust the supply and spray intensity of cooling water according to preset process parameters or real-time temperature feedback data, thereby ensuring the stability and controllability of the cooling process.

[0093] Through the above technical solution, after the bimetallic bearing is centrifugally cast, the cooling water nozzle 24 can quickly and evenly spray cooling water onto the outer circumference of the entire circular tube. This cooling water is precisely delivered and controlled by the cold water control pipe 10. This external forced cooling method can efficiently remove heat from the surface of the entire circular tube, significantly accelerating the solidification process of the molten copper alloy, thus effectively solving the problems of low cooling efficiency and uneven cooling that may exist in traditional cooling methods. Rapid and uniform cooling can not only significantly shorten the production cycle and improve overall production efficiency, but also help avoid problems such as stress concentration and deformation within the entire circular tube and defects at the interface between the copper alloy and the bearing caused by uneven cooling, thereby ensuring the bonding quality and dimensional accuracy of the bimetallic bearing. In addition, through the precise control of the cooling water flow and temperature by the cold water control pipe 10, this device can flexibly adjust the cooling parameters according to different material properties and bearing dimensions, realizing the flexibility and optimization of the process, and further improving the product qualification rate and stability.

[0094] In some embodiments described above, a mobile casting device is proposed to centrifugally cast molten copper alloy into the inner wall of a circular tube. However, in its implementation, ensuring that the mobile casting device can move stably and accurately along a predetermined path under high-temperature conditions, and accurately deliver the molten metal into the high-speed rotating circular tube, is a key issue affecting casting quality and production efficiency. Inaccurate or unstable movement may lead to uneven casting, overflow, or even equipment damage.

[0095] In this regard, this application further proposes that the mobile casting device includes a guide rail 8 connected to the lathe bed, the guide rail 8 is connected to a sliding trolley 9, and the sliding trolley 9 is movably connected to a casting trolley 7.

[0096] Specifically, the guide rail 8 is securely mounted and fixed to the lathe bed. This guide rail 8 can take various forms, such as linear guides, dovetail guides, or roller guides, and its main function is to provide a precise and stable linear motion trajectory for the moving casting device. The material and precision of the guide rail 8 should be able to withstand the thermal stress and mechanical loads during the casting process to ensure long-term stability.

[0097] The sliding carriage 9 is connected to the guide rail 8 and serves as a carrier for linear movement along the guide rail 8. The sliding carriage 9 typically includes a slider or roller mechanism that matches the guide rail 8 to achieve smooth, low-friction, and high-precision movement. The movement of the sliding carriage 9 can be precisely controlled by an external drive mechanism (such as a lead screw and nut mechanism, a rack and pinion mechanism, or a hydraulic / pneumatic push rod), thereby achieving the positioning and feeding of the casting carriage 7.

[0098] The casting carriage 7 is movably connected to the sliding carriage 9. The casting carriage 7 is the component that directly carries and transports the molten copper alloy. It typically has a crucible or hopper for holding the molten metal and a casting nozzle for controlling the flow rate. Through the movement of the sliding carriage 9, the casting carriage 7 can be precisely positioned at the inlet of the circular tube and move along the axial direction of the tube at a set speed to achieve uniform spreading of the molten copper alloy on the inner wall of the tube. The term "movably connected" here means that the casting carriage 7 can be reliably fixed to the sliding carriage 9 and moves with it. It may also have interfaces for fine-tuning or quick disassembly to accommodate different casting needs or maintenance operations.

[0099] Through the above technical solution, the movement trajectory of the mobile casting device is precisely defined by the guide rail 8, and the sliding trolley 9 runs smoothly on the guide rail 8, thereby driving the casting trolley 7 to achieve precise linear feed. This structure effectively solves the problems of inaccurate positioning and unstable movement of the mobile casting device during high-temperature casting. It ensures that the molten copper alloy can be uniformly injected into the inner wall of the rotating circular tube at a preset speed and position, avoiding bearing defects caused by uneven casting, such as uneven thickness, eccentricity, or local non-bonding. At the same time, precise motion control also improves operational safety and reduces the risk of manual intervention, thereby significantly improving the automation level, product quality stability, and production efficiency of bimetallic bearing centrifugal casting.

[0100] In the centrifugal casting process of bimetallic bearings based on lathes, the hydraulic tensioning rotary tooling assembly operates in an environment of high-speed rotation, high-temperature heating, and molten copper alloy casting. This poses safety hazards such as molten metal splashing, high-temperature radiation, and rotating parts, which may cause injury to operators and affect the stability of equipment operation.

[0101] In this regard, this application further proposes that the hydraulic tensioning rotary tooling assembly is provided with a protective cover 5 on its outer periphery, and the protective cover 5 is connected to a second drive rod 3.

[0102] Specifically, the protective cover 5 is a structure used to cover or surround the outer periphery of the hydraulic tensioning rotary tooling assembly, designed to provide physical isolation and safety protection. The protective cover 5 is primarily used to isolate potential hazards generated during the operation of the hydraulic tensioning rotary tooling assembly, such as high-speed rotating parts, high-temperature areas, and molten metal splashes. The protective cover 5 can be made of high-temperature and corrosion-resistant metal materials, such as stainless steel or alloy steel, or composite materials, and designed as a closed or semi-closed structure to effectively block splashes and heat radiation. The structural design of the protective cover 5 should ensure that it provides adequate protection without affecting the normal operation and maintenance of the equipment. For example, it can be designed with openable or removable doors, observation windows, etc., to facilitate the loading and unloading of workpieces and the monitoring of equipment status.

[0103] The second drive rod 3 is a mechanical component used to drive or control the movement of the protective cover 5. The function of the second drive rod 3 is to open, close, or position the protective cover 5 to facilitate the loading and unloading of workpieces, equipment debugging, or maintenance. The second drive rod 3 can be a pneumatic rod, a hydraulic rod, an electric actuator, or a manual operating lever. For example, when pneumatically or hydraulically driven, the second drive rod 3 is powered by a pneumatic or hydraulic system to achieve automatic or semi-automatic opening and closing of the protective cover 5, thereby improving operational efficiency and safety. When an electric actuator is used, precise position control of the protective cover 5 can be achieved through a motor-driven lead screw or gear mechanism. A manual operating lever is suitable for applications where automation requirements are low or where manual intervention is necessary.

[0104] By employing the aforementioned technical solution, a protective cover 5 is installed around the hydraulic tensioning rotary tooling assembly, effectively isolating high-speed rotating components, high-temperature areas, and molten copper alloy splashes. This significantly reduces the safety risks faced by operators during centrifugal casting. Simultaneously, the second drive rod 3 connected to the protective cover 5 makes opening and closing the cover 5 more convenient and controllable, ensuring safety during workpiece loading and unloading and equipment operation. It avoids direct human contact with hazardous areas, further enhancing the overall safety and ease of operation of the device and guaranteeing the stable operation of the production process.

[0105] In some of the embodiments described above in this application, a lathe-based bimetallic bearing centrifugal casting device is proposed, which has functions such as rotation, heating, hydraulic tensioning, and molten metal conveying. However, in actual operation, how to efficiently and accurately utilize these device components to ensure the stable clamping of the semi-circular bearing, the uniform casting of the molten copper alloy, and the quality of the final product still requires a systematic operating procedure to guide the process.

[0106] In response, this application further proposes a lathe-based centrifugal casting method for bimetallic bearing bushes, which includes the following steps:

[0107] First, the initial assembly and positioning of the workpiece are performed. Specifically, two semi-circular bearing bushes 11 are joined together to form a complete circular tube, and one end of this complete circular tube is connected to the second circular tensioning ring 23. This step aims to initially fix the semi-finished workpiece to be cast on the tooling, laying the foundation for subsequent tensioning and rotation operations. This connection method can adopt various forms such as tight fit, snap-fit, or threaded connection to ensure stable mechanical coupling between the complete circular tube and the second circular tensioning ring 23.

[0108] Next, prepare the heating device. Fit the heating coil 22 of the induction heating device 21 around the outer circumference of the circular tube. This step aims to precisely position the heating coil 22 outside the circular tube so that the tube can be efficiently and uniformly inducted in subsequent steps. The fitting of the heating coil 22 should ensure that an appropriate gap is maintained between it and the circular tube to optimize heating efficiency and uniformity.

[0109] Next, the spindle drive assembly is axially positioned. The first drive rod 2 drives the spindle drive assembly to move axially along the drive shaft 36 via the drive bracket 4, bringing it close to the complete circular tube until the complete circular tube abuts against the first circular tensioning ring 28. This step, by precisely controlling the axial position of the spindle drive assembly, ensures that the other end of the complete circular tube aligns with the first circular tensioning ring 28, thereby connecting both ends of the complete circular tube to the tooling on the spindle drive assembly side and the tailstock assembly side, respectively, preparing for subsequent overall tensioning and rotation.

[0110] Subsequently, the entire circular tube is hydraulically tightened and sealed. The hydraulic tightening rotating fixture assembly is driven, and the hydraulic tie rod 18 drives the first circular tightening ring 28 to move axially, causing the first circular tightening ring 28 and the second circular tightening ring 23 to tighten the entire circular tube in opposite directions using two tightening ramps. This step is crucial for ensuring casting quality. The axial thrust of the hydraulic tie rod 18, through the tightening ramps on the first and second circular tightening rings 28 and 23, radially compresses the entire circular tube. Because the two tightening ramps are set in opposite directions, when the hydraulic tie rod 18 applies axial force, a centripetal radial component force is generated, effectively tightly binding the two semi-circular bearings 11 and sealing both ends of the entire circular tube, preventing the molten copper alloy from overflowing during centrifugal casting.

[0111] After tensioning is completed, the spindle drive motor 1 is started, causing the drive shaft 36 to rotate the entire round tube. Simultaneously, the heating coil 22 heats the entire round tube to the set temperature. This step involves the rotation and heating of the entire round tube simultaneously. The spindle drive motor 1 provides rotational power, causing the entire round tube to rotate at a preset speed at high speed, providing the necessary centrifugal force for centrifugal casting. At the same time, the induction heating coil 22 heats the entire round tube, bringing its inner wall to a temperature at which the molten copper alloy can effectively wet and metallurgically bond, which is crucial for forming a strong bonding layer.

[0112] Finally, the molten copper alloy is cast, cooled, and the product is separated. Molten copper alloy is added to the casting carriage 7, which, via guide rails 8 and a sliding carriage 9, feeds the molten copper alloy through the inner hole 33 of the bushing 35 of the tailstock assembly into the inner wall of the circular tube. The rotating inner wall of the circular tube, through centrifugal force, adheres and fuses the molten copper alloy to the inner wall, achieving the set fusion thickness based on the input volume of molten copper alloy. After cooling by cooling water from the cooling water nozzle 24, the two semi-circular bearings 11 are cut and separated to obtain the bimetallic bearing. This step is the core of centrifugal casting. Under centrifugal force, the molten copper alloy spreads evenly and solidifies on the inner wall of the circular tube, forming a dense lining. Precise control of the lining thickness can be achieved by precisely controlling the moving speed of the casting carriage 7 and the flow rate of the molten copper alloy. After casting, the cooling water nozzle 24 sprays cooling water to accelerate the solidification of the copper alloy and ensure a uniform microstructure. Finally, by cutting and separating, a bimetallic bearing that meets the requirements can be obtained.

[0113] Through the above technical solution, this application provides a systematic and operable centrifugal casting method for bimetallic bearing bushes. This method, through clearly defined steps, guides operators to efficiently complete the assembly of the semi-circular bearing bush, the precise tightening and sealing of the tooling, the preheating of the entire circular tube, and the centrifugal casting and cooling of the molten copper alloy. In particular, by driving the tightening inclined plane with hydraulic rod 18 to tighten the entire circular tube in the opposite direction, the problems of molten metal overflow and loose bearing bush fit are effectively solved, ensuring the stability of the casting process and product quality. Simultaneously, with rotation and heating occurring simultaneously, the molten copper alloy can uniformly adhere to and form a good metallurgical bond with the inner wall of the entire circular tube, avoiding segregation and defects. Finally, by precisely controlling the casting thickness and cooling process, bimetallic bearing bushes with excellent performance can be stably obtained, significantly improving production efficiency and product qualification rate.

[0114] The above description is merely an embodiment of this application and is not intended to limit the scope of protection 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 protection of this application.

Claims

1. A centrifugal casting device for bimetallic bearings based on a lathe, characterized in that: The lathe includes a lathe bed, with a spindle drive assembly at one end and an axially hollow tailstock assembly at the other end. The spindle drive assembly and the tailstock assembly are connected end-to-end by a hydraulic tensioning rotary tooling assembly. The hydraulic tensioning rotary tooling assembly rotates and seals the whole round tube formed by the two semi-circular bearings (11) that hug each other. The hydraulic tensioning rotary tooling assembly connects the spindle drive assembly and the tailstock assembly. The axially hollow structure of the tailstock assembly is used in conjunction with a mobile casting device. The casting carriage (7) of the mobile casting device sends molten copper alloy into the inner wall of the whole round tube. The outer wall of the whole round tube is used in conjunction with the heating coil (22) of the induction heating device (21). The whole round tube rotates under the drive of the spindle drive assembly, and the copper alloy liquid is centrifugally poured into the inner wall of the heated whole round tube. After the whole round tube is cooled, the two semi-circular bearings are separated to complete the centrifugal casting of the bimetallic bearing.

2. The centrifugal casting device for bimetallic bearings based on a lathe according to claim 1, characterized in that: The lathe bed and the spindle drive assembly are connected by a drive bracket (4). The drive bracket (4) is equipped with a first drive rod (2). The first drive rod (2) drives the spindle drive assembly to move along the slider (25) of the lathe bed. The spindle drive assembly includes a spindle drive motor (1). The spindle drive motor (1) is connected to the drive pulley (16). The drive pulley (16) is connected to the driven pulley (161) through a belt (162). The center of the driven pulley (161) is connected to the drive shaft (36) through a pin. The outer periphery of the drive shaft (36) is connected to the cooling water tank (12) through two ball bearings (17). The cooling water tank (12) is connected to the cooling water through a pipe.

3. The centrifugal casting device for bimetallic bearings based on a lathe according to claim 2, characterized in that: The drive shaft (36) has two ends that extend out of the cooling water tank (12). One end is connected to the first flange (15), and the other end is connected to the hydraulic oil pump (13). The hydraulic oil pump (13) drives the hydraulic tie rod (18) to move back and forth. The drive shaft (36) has an axial through-hole structure. The hydraulic tie rod (18) passes through the hollow structure. The hydraulic tie rod (18) passes through the first flange (15) and is connected to the hydraulic tensioning rotary tooling assembly.

4. The centrifugal casting device for bimetallic bearings based on a lathe according to claim 3, characterized in that: The hydraulic tensioning rotary tooling assembly includes a connecting column (20), with an enlarged second flange (26) and a third flange (27) at both ends of the connecting column (20). The second flange (26) is connected to the first flange (15), and the third flange (27) is connected to the first circular tensioning ring (28). The first circular tensioning ring (28) is connected to one end of the whole circular tube, and the other end of the whole circular tube is connected to the second circular tensioning ring (23). The second circular tensioning ring (23) is connected to the tailstock assembly. The first circular tensioning ring (28), the second circular tensioning ring (23), and the connection end of the whole circular tube are all provided with tensioning inclined surfaces. The two tensioning inclined surfaces are set in opposite directions relative to the whole circular tube. When the whole circular tube is subjected to axial force, the two semi-circular bearings (11) are radially pressed by the two tensioning inclined surfaces to prevent the molten copper alloy from overflowing.

5. The centrifugal casting device for bimetallic bearings based on a lathe according to claim 3, characterized in that: The hydraulic tie rod (18) is sequentially connected to the drive shaft (36), the first axial inner hole (29) of the connecting column (20), and the second inner hole (30) at the center of the first circular tensioning ring (28). The outer end of the hydraulic tie rod (18) is fastened to the second inner hole (30).

6. The centrifugal casting device for bimetallic bearings based on a lathe according to claim 1, characterized in that: The tailstock assembly includes a tailstock housing (6), which is provided with a fourth flange (14) that connects to a second circular tension ring (23). The fourth flange (14) is integrally formed and connected to a bushing (35). The inner hole (33) of the bushing (35) is connected to the center hole (31) of the second circular tension ring (23). The outer circumference of the bushing (35) is fitted with a second ball bearing (32) installed inside the tailstock housing (6). The tailstock housing (6) is provided with a second cooling water pipe (34) on its side. The second cooling water pipe (34) outputs cooling water to cool the second ball bearing (32) and the bushing (35).

7. The centrifugal casting device for bimetallic bearings based on a lathe according to claim 1, characterized in that: The outer circumference of the circular tube is fitted with a cooling water nozzle (24), which is connected to a cold water control pipe (10).

8. The centrifugal casting device for bimetallic bearings based on a lathe according to claim 1, characterized in that: The mobile casting device includes a guide rail (8) connected to the lathe bed, the guide rail (8) is connected to a sliding carriage (9), and the sliding carriage (9) is movably connected to a casting carriage (7).

9. The centrifugal casting device for bimetallic bearings based on a lathe according to claim 1, characterized in that: The hydraulic tensioning rotary tooling assembly is provided with a protective cover (5) on its outer periphery, and the protective cover (5) is connected to a second drive rod (3).

10. A lathe-based centrifugal casting method for bimetallic bearing bushes according to any one of claims 1 to 9, characterized in that: Includes the following steps: Step 1: Connect one end of the two semi-circular bearings (11) that are joined together to form a complete circular tube to the second circular tensioning ring (23). Step 2: Fit the heating coil (22) of the induction heating device (21) onto the outer circumference of the round tube; Step 3: The first drive rod (2) drives the main shaft drive assembly to move axially along the drive shaft (36) and approach the whole round tube until the whole round tube abuts against the first circular tensioning ring (28). Step 4: Drive the hydraulic tensioning rotary tooling assembly. The hydraulic tie rod (18) drives the first circular tensioning ring (28) to move axially, so that the first circular tensioning ring (28) and the second circular tensioning ring (23) use two tensioning inclined surfaces to tension the whole circular tube in opposite directions. Step 5: Start the main spindle drive motor (1) to make the drive shaft (36) drive the whole round tube to rotate, and at the same time heat the whole round tube to the set temperature through the heating coil (22); Step 6: Add the molten copper alloy liquid to the casting carriage (7). The casting carriage (7) is driven by the sliding carriage (9) through the guide rail (8) to input the molten copper alloy liquid into the inner wall of the round tube through the inner hole (33) of the bushing (35) of the tailstock assembly. The rotating inner wall of the round tube will attach and fuse the copper alloy liquid to the inner wall of the round tube by centrifugal force. According to the input copper alloy liquid volume, the set fusion thickness is reached. After cooling by the cooling water output by the cooling water nozzle (24), the two semi-circular bearings (11) are cut and separated to obtain the bimetallic bearing.

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