A hub bearing outer ring is ground by a vehicle grinding device and a method for processing the same

Abstract

The present application relates to the technical field of hub bearing machining, particularly to a lathe machining equipment and method for hub bearing outer ring, comprising a lathe main body, characterized in that: the lathe main body comprises a lathe shell, an operation panel is connected to one side of the outer wall of the lathe shell, a lathe hatch is arranged on the outer wall of the lathe shell, a lathe bed is arranged in the lathe shell, a large apron and a lead screw driving unit for driving the large apron to move along the bed rail in the axial direction are arranged on the lathe bed; a tool holder base is arranged on one side of the top of the large apron, a turret tool holder is connected to one side of the tool holder base, a cutting fluid spray pipe is connected to one side of the tool holder base, the present application integrates double-spindle driving and a composite clamp system, solves the problems of poor cutting rigidity of thin-walled parts and difficult clamping deformation: double-spindle synchronous transmission + limiting ring constraint, inhibits chatter, ensures roundness and coaxiality; integrated chain-type chip removal + magnetic separation closed-loop cooling, automatically separates and circulates chips and cutting fluid, reduces cleaning intensity.

Description

Technical Field

[0001] This invention relates to the field of wheel hub bearing processing equipment technology, and in particular to a wheel hub bearing outer ring machining equipment and processing method that uses turning instead of grinding. Background Technology

[0002] With the rapid development of the automotive industry and high-end equipment manufacturing, wheel hub bearing units, as core safety components of vehicle driving systems, face stringent requirements regarding the dimensional accuracy, geometric tolerances, and surface micro-quality of their inner and outer raceways. Traditional manufacturing processes typically employ a multi-step process of "rough turning—finish turning—grinding" to ensure final precision. However, grinding itself has inherent drawbacks, including low processing efficiency, rapid wheel wear, and the risk of coolant deterioration and foul odor, resulting in significant environmental pollution. Furthermore, the multi-step process increases the risk of workpiece damage and overall manufacturing costs, making it difficult to adapt to the current trends of green manufacturing and cost reduction / efficiency improvement. Although the industry has long proposed the concept of "replacing grinding with turning," attempting to directly replace the fine grinding process with ultra-high precision hard turning, in actual production, due to the fact that the outer ring of the wheel hub bearing is a typical large thin-walled annular part, existing general-purpose CNC lathes generally suffer from key technical bottlenecks such as insufficient machine tool rigidity leading to obvious cutting vibration marks, easy elastic deformation or out-of-roundness of the workpiece during clamping, poor dual-spindle synchronous drive and thermal deformation control capabilities, and low efficiency of automated cleaning of heavy steel chips and cutting fluid mixtures. As a result, the machined products are difficult to consistently achieve the surface roughness and geometric tolerances of grinding, which seriously restricts the promotion and application of this technology.

[0003] Chinese patent discloses a turning and milling machine for wheel hub bearings (publication number: CN 202742034 U), which includes a worktable with a transverse sliding guide fixed on it. A transverse slide plate is inserted into the transverse sliding guide, and a transverse nut is fixed to the lower part of the transverse slide plate. A transverse lead screw is fixed to the shaft of a transverse servo motor and screwed onto the transverse nut. A longitudinal sliding guide is fixed on the transverse slide plate, and a longitudinal slide plate is inserted into the longitudinal sliding guide. However, this type of processing equipment uses traditional multi-process flow, which is not only inefficient and causes rapid wear of grinding wheels and environmental pollution, but also fails to meet the requirements of cost reduction and efficiency improvement. In addition, conventional chucks are prone to deformation when clamping thin-walled parts, insufficient rigidity of single spindle drive causes cutting chatter, and there are structural defects such as low degree of chip removal automation, which make it impossible for the product to consistently achieve grinding-grade precision. Therefore, there is a need for a turning machine for wheel hub bearing outer rings instead of grinding and its processing method. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of traditional processes that use a multi-step "turning-grinding" process, which is not only inefficient and causes rapid wear of grinding wheels and environmental pollution, but also fails to meet the requirements of cost reduction and efficiency improvement. Furthermore, existing general-purpose lathes, when "turning instead of grinding", are limited by structural defects such as the conventional chuck causing deformation of thin-walled parts, insufficient rigidity of the single spindle drive leading to cutting chatter, and low degree of chip removal automation. As a result, the products can never consistently achieve grinding-grade precision, which seriously restricts the application of the technology. Therefore, this invention proposes a turning-instead-of-grinding processing equipment and method for wheel hub bearing outer rings.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: A lathe body for machining the outer ring of a wheel hub bearing using turning instead of grinding, comprising a lathe body, characterized in that: the lathe body includes a machine tool housing; an operation panel is connected to one side of the outer wall of the machine tool housing; a machine tool door is provided on the outer wall of the machine tool housing; a machine tool bed is provided inside the machine tool housing; a large slide and a lead screw drive unit for driving the large slide to move axially along the bed guide rail are provided on the machine tool bed; a tool post base is provided on one side of the top of the large slide; a turret tool post is connected to one side of the tool post base; a cutting fluid spray pipe is connected to one side of the tool post base; a power spindle drive assembly is provided on one side of the tool post base, and an auxiliary spindle drive assembly is provided on the other side; a drive chuck unit is provided between the power spindle drive assembly and the auxiliary spindle drive assembly; a discharge port is provided on one side of the machine tool housing, and an external water tank is provided on the other side; a magnetic separator is provided at one end of the discharge port, and a chain-plate chip conveyor is connected to one end of the magnetic separator. This solution constructs a highly integrated and automated closed-loop machining system. Through integrated design, the turning, workpiece positioning, coolant supply, and chip handling modules are organically combined, eliminating the gaps between the functional units and significantly improving the overall structural rigidity and stability of the machine. This layout not only ensures vibration suppression during processing but also achieves self-cleaning of the processing environment through the built-in chip removal and filtration system. It provides a basic platform for the high-precision and high-stability machining required for "turning instead of grinding," while simplifying the equipment footprint and operation process.

[0006] Preferably, the power spindle drive assembly includes a power spindle servo motor, one end of which is connected to a master-driven pulley. A secondary driven pulley is located above the top of the master-driven pulley, and a synchronous belt connects the master-driven pulley and the secondary driven pulley. One end of the secondary driven pulley is connected to the spindle box. This solution introduces a synchronous belt drive mechanism, utilizing its inherent damping characteristics to effectively block and absorb the torsional vibrations and high-frequency harmonics generated during servo motor operation. This flexible transmission method makes the rotational motion of the spindle box smoother and less impactful, greatly improving the rotational accuracy and dynamic stability of the spindle system. This is crucial for achieving mirror-level surface roughness in "turning instead of grinding" processes, preventing tool mark replication caused by spindle vibration.

[0007] Preferably, the auxiliary spindle drive assembly includes a machine tool tailstock, on which a secondary spindle servo motor is mounted. The secondary spindle servo motor has a protective cover on its outer wall, and one end of the secondary spindle servo motor is connected to a tailstock chuck. This solution overcomes the limitation of traditional tailstocks only providing passive support, giving the tailstock active driving capability. Through the dual-spindle synchronous drive mode, a force state is formed on the outer ring of the wheel hub bearing, where both ends are clamped and driven together, completely changing the problem of insufficient rigidity caused by the long overhang of the workpiece in single-end drive. This significantly enhances the workpiece's resistance to bending and torsion under high-speed cutting, effectively suppresses chatter in workpieces with a large length-to-diameter ratio, and ensures consistent machining accuracy throughout the entire stroke.

[0008] Preferably, the drive chuck unit includes a chuck body, an annular mounting platform, a telescopic hydraulic cylinder, a radial slider, a limiting ring, a three-jaw chuck, grippers, and the outer ring of the wheel hub bearing to be processed, which are sequentially coupled. The chuck body is a cylindrical shell structure with an annular mounting platform on its front end face. The grippers are at least three in number and are evenly distributed on the radial groove surface of the radial slider. The limiting ring is an annular structure that is coaxially fitted onto the outer side of the outer circle of the wheel hub bearing to be processed and engages with the inner side of the grippers. A positioning rod assembly is provided on one side of the outer wall of the limiting ring. This solution addresses the thin-walled and easily deformable characteristics of the outer ring of the wheel hub bearing by adopting a combined clamping strategy of "outer circle limiting + inner support / outer clamping". The limiting ring forms a wrapping constraint on the outer circle of the workpiece, evenly distributing the clamping force and fundamentally avoiding elliptical deformation caused by local stress concentration in thin-walled parts. Meanwhile, the cooperation between the positioning rod assembly and the limit ring enables the workpiece to be quickly centered and axially positioned, ensuring the repeatability of positioning accuracy during batch processing and solving the functional problems of easy loosening and deviation when the traditional fixture clamps the outer ring of the wheel hub.

[0009] Preferably, one end of the tailstock chuck is provided with a tailstock ejector pin, and one end of the tailstock ejector pin is provided with a flexible ejector pin. The flexible ejector pin is coaxially disposed at the front end of the tailstock body and mates with the outer ring end face of the wheel hub bearing to be processed. This solution introduces an adaptive compensation mechanism. When contacting the workpiece end face, the flexible ejector pin can automatically adapt to the micro-unevenness or heat treatment warping present on the end face, ensuring that the ejector pin and the workpiece end face achieve surface or line contact, rather than single-point hard contact. This effectively prevents positioning eccentricity or axial movement caused by defects in the workpiece end face, while protecting the workpiece end face from being scratched by the hard ejector pin, improving the reliability of workpiece clamping and the quality integrity of the final product.

[0010] Preferably, the positioning rod assembly includes a positioning rod, which is a rod-shaped structure with a positioning bolt at its front end that mates with the end face of the outer ring of the wheel hub bearing. This solution provides a precise axial positioning reference. By engaging with a preset feature on the end face of the outer ring of the wheel hub bearing, the axial degree of freedom of the workpiece can be quickly eliminated, achieving precise positioning with "one face, one hole". This avoids the cumulative error caused by relying on the chuck clamping length for positioning, significantly improves the angular positioning accuracy of the workpiece in the circumferential direction, and ensures the positional accuracy of features such as oil holes and grooves relative to the reference surface.

[0011] Preferably, the chain-plate chip conveyor includes an inclined conveyor frame, inside which a chain-plate conveying unit is installed. One end of the chain-plate conveying unit is connected to a chain-plate servo motor. One end of the conveyor frame has a feed hopper, and the other end has a discharge hopper. One end of the discharge hopper has a tilting chip collection cart. The bottom of the conveyor frame has at least two support legs. Transparent splash guards are provided on both sides of the discharge hopper. This solution constructs a highly efficient heavy-duty chip conveying channel. The inclined design and chain-plate conveying ensure that high-temperature, heavy steel chips can be quickly removed from the processing area, preventing chip accumulation that could lead to secondary cutting by the tool or equipment damage. The transparent splash guards, while allowing operators to observe the chip removal process, also create a physical barrier to prevent cutting fluid and debris from splashing and contaminating the workshop environment, thus improving the cleanliness and safety of equipment operation.

[0012] Preferably, the tilting chip collection vehicle includes a bin for receiving chips conveyed by a chain-type chip conveyor; the bottom of the bin is equipped with at least three braked swivel casters and a mounting frame, the braked swivel casters are mounted on the bottom of the mounting frame, and lifting and tilting mechanisms are provided on both sides of the bin. Each lifting and tilting mechanism includes a cross-link hydraulic unit, one end of which is connected to an operating control lever. This solution achieves mechanized handling and unloading of chip collection. Through the hydraulic lifting and tilting mechanism, operators only need to operate the control lever to complete the tilting operation of a heavy-duty material cart fully loaded with chips, completely eliminating the labor intensity and safety hazards caused by manually tilting heavy-duty material carts. The braked swivel casters ensure the stability and flexibility of the collection vehicle during movement and tilting, optimizing the ergonomic design of factory logistics management.

[0013] Preferably, the magnetic separator includes a mounting frame with a magnetic roller unit mounted on it. One end of the magnetic roller unit is connected to a roller servo motor. A water tank is located on one side of the magnetic roller unit, and a chip separation tank is located on the other side. A filter and a cooling water tank are connected to the outlet of the water tank at the bottom of the water tank, and one end of the cooling water tank is connected to an external water tank. This solution establishes a highly efficient solid-liquid separation defense line. The magnetic roller unit automatically adsorbs fine ferromagnetic particles flowing through the cutting fluid, achieving real-time purification and regeneration of the coolant. This effectively prevents tiny metal particles from flowing back into the machining area with the coolant, causing abnormal tool wear or workpiece surface scratches. Maintaining the long-term cleanliness of the coolant not only extends the service life of the cutting fluid but also provides a crucial guarantee for the ultra-clean machining environment required for "turning instead of grinding."

[0014] Preferred: Step 1: Pre-clamping preparation and establishment of positioning reference After the operator sets the processing parameters through the control panel, they open the machine tool door and place the wheel hub bearing outer ring blank to be processed on the limit ring of the drive chuck unit. At this time, the jaws are in a retracted state (leaving a clamping gap of about 1 mm) to ensure that the workpiece can be loaded smoothly. At the same time, the telescopic hydraulic cylinder drives the radial slider to slide along the radial groove, driving at least three jaws to pre-position the inner wall of the workpiece, preparing for subsequent clamping. Step 2: Workpiece clamping and axial positioning The robot grips the workpiece and loads it into the fixture. Then, the chuck opens, creating a gap of approximately 0.02 to 0.03 mm between the gripper and the limiting ring (coaxially fitted on the outer side of the workpiece's outer diameter) (this gap represents the allowable runout range of the workpiece). Next, the tailstock ejector moves forward, pressing the workpiece end face with a flexible ejector (installed at the front end of the tailstock body), achieving precise axial positioning of the workpiece. Simultaneously, the positioning bolt at the front end of the positioning rod assembly engages with a pre-drilled hole on the workpiece end face, restricting axial sliding of the workpiece and completing omnidirectional positioning of the workpiece. Step 3: Dual-spindle synchronous drive and rigidity reinforcement After machining starts, the power spindle servo motor of the power spindle drive assembly starts, and the power is transmitted to the auxiliary driven pulley through the main driven pulley and synchronous belt, ultimately driving the spindle box to rotate; at the same time, the auxiliary spindle servo motor of the auxiliary spindle drive assembly (externally protected by a motor protective cover) starts, and drives the tailstock chuck to rotate synchronously, so that the outer ring of the wheel hub bearing to be processed forms a high-rigidity, non-overhanging rotary motion under the drive of both ends; Step 4: Precision turning The lead screw drive unit drives the large slide to feed axially along the guide rail of the machine tool bed. The turret tool post on the tool post base automatically changes tools according to the machining program to perform hard turning on the outer raceway of the rotating workpiece. During the machining process, the cutting fluid spray nozzle continuously sprays coolant to achieve cooling, lubrication and chip removal functions, ensuring that the machined surface quality meets the precision requirements of "turning instead of grinding". Step 5: Separation and recovery of chips and coolant The mixture of chips and cutting fluid generated during processing is flushed to the discharge port and first enters the magnetic separator: the mixture flows through the lower water tank to the magnetic roller unit, the roller servo motor drives the magnetic roller unit to run, the magnetic roller attracts ferromagnetic chips and conveys them to the chip separation tank; the separated chips fall into the chain plate chip conveyor below, while the filtered cutting fluid flows back to the cooling water tank (connected to the external water tank) through the filter, realizing the recycling of the coolant; Step Six: Chip Conveying and Centralized Collection The chain conveyor unit inside the chain plate chip conveyor is driven by a chain plate servo motor, which conveys the chips upward along the inclined conveyor frame (supported by at least two support legs at the bottom). The chips enter the discharge hopper through the feed hopper and finally fall into the bin of the tilting chip collection vehicle. The transparent splash guards on both sides of the discharge hopper prevent the cutting fluid from splashing. The bottom of the tilting chip collection vehicle is equipped with braked swivel casters for easy movement. Its lifting and tilting mechanism (including a cross-link hydraulic unit and operating control lever) can realize the tilting unloading of the bin. Step 7: Processing Completion and Unloading After processing, the chuck body tightens again, firmly clamping the limit ring; the tailstock ejector pin retracts, releasing the axial clamping on the workpiece; the robot grabs the workpiece again and removes the finished product from the drive chuck unit, thus completing one complete processing cycle.

[0015] The advantages of this invention are: This invention fundamentally overcomes the challenges of rigidity deficiency and clamping deformation in thin-walled annular parts under heavy cutting conditions by constructing an integrated dual-spindle drive architecture and a dedicated composite clamping system. The power spindle and auxiliary spindle achieve coordinated torque output through synchronous belt drive, combined with a limit ring for full-circumferential constraint positioning of the workpiece's outer diameter. This significantly suppresses cutting chatter caused by excessive length-to-diameter ratio and structurally ensures the roundness and coaxiality of the workpiece under clamping conditions. Simultaneously, the equipment integrates a chain-type chip removal and magnetic separation closed-loop cooling system, utilizing a magnetic roller unit to cool the chips. High-efficiency adsorption and filtration filters remove impurities from the cutting fluid, enabling automatic separation and recycling of chips and coolant. This maintains the cleanliness of the machining area while significantly reducing the cleaning intensity and frequency of human intervention for operators. Furthermore, the cross-link hydraulic unit and flexible ejector pin of the tilting chip collection cart further optimize ergonomics and positioning adaptability. The tilting chip collection cart, with its braked swivel casters and lifting tilting mechanism, facilitates convenient chip transfer. The flexible ejector pin's adaptive clamping of the workpiece end face enhances the clamping stability of thin-walled parts. Ultimately, the entire machine achieves high-precision, high-efficiency, low-cost, and green machining of wheel hub bearing outer rings without relying on subsequent grinding processes, fundamentally eliminating the quality risks and cost losses associated with the traditional multi-process "turning-grinding" workflow. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the main structure of the lathe of the present invention.

[0019] Figure 3 This is a schematic diagram of the internal structure of the lathe body of the present invention.

[0020] Figure 4 This is a schematic diagram of the magnetic separator structure of the present invention.

[0021] Figure 5 This is a schematic diagram of the chain plate type chip conveyor of the present invention.

[0022] Figure 6 This is a schematic diagram of the drive chuck unit structure of the present invention.

[0023] In the diagram: 1. Lathe body; 2. Control panel; 3. External water tank; 4. Discharge port; 5. Magnetic separator; 6. Chain-type chip conveyor; 7. Machine tool housing; 8. Machine tool door; 9. Power spindle servo motor; 10. Synchronous belt; 11. Spindle box; 12. Drive chuck unit; 13. Turret tool post; 14. Cutting fluid nozzle; 15. Tool post base; 16. Large slide; 17. Tailstock chuck; 18. Sub-spindle servo motor; 19. Machine tool tailstock; 20. Lead screw drive unit; 22. Machine tool bed; 23. Chip removal groove; 24. 25. Magnetic roller unit; 26. Water tank; 27. Roller servo motor; 28. Mounting frame; 29. ​​Cooling water tank; 30. Feed hopper; 31. Conveyor frame; 32. Chain plate servo motor; 33. Transparent splash guard; 34. Discharge hopper; 35. Bin body; 36. Universal caster with brake; 37. Cross-link hydraulic unit; 38. Chuck body; 39. Annular mounting platform; 40. Radial slider; 41. Gripper; 42. Limit ring; 43. Positioning rod; 44. Outer ring of the wheel hub bearing to be processed; 45. Flexible ejector pin; 46. Tailstock ejector pin. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0025] Please see Figures 1-6As shown, a lathe-based machining equipment for the outer ring of a wheel hub bearing, comprising a lathe body 1, characterized in that: the lathe body 1 includes a machine tool housing 7, an operation panel 2 connected to one side of the outer wall of the machine tool housing 7, a machine tool door 8 provided on the outer wall of the machine tool housing 7, a machine tool bed 22 provided inside the machine tool housing 7, a large slide 16 and a lead screw drive unit 20 for driving the large slide 16 to move axially along the bed guide rail on the machine tool bed 22; a tool post base 15 is provided on one side of the top of the large slide 16. A turret tool post 13 is connected to one side of the tool post base 15, and a cutting fluid spray pipe 14 is connected to the other side. A power spindle drive assembly is located on one side of the tool post base 15, and an auxiliary spindle drive assembly is located on the other side. A drive chuck unit 12 is shared between the power spindle drive assembly and the auxiliary spindle drive assembly. A discharge port 4 is located on one side of the machine tool housing 7, and an external water tank 3 is located on the other side. A magnetic separator 5 is located at one end of the discharge port 4, and a chain-plate chip conveyor 6 is connected to one end of the magnetic separator. This solution constructs a highly integrated and automated closed-loop machining system. Through integrated design, turning, workpiece positioning, coolant supply, and chip handling functional modules are organically integrated, eliminating the cooperation gaps between functional units and significantly improving the structural rigidity and stability of the entire machine. This layout not only ensures vibration suppression during processing, but also achieves self-cleaning of the processing environment through the built-in chip removal and filtration system. It provides a basic platform for the high-precision and high-stability processing required for "replacing grinding with turning", while simplifying the equipment footprint and operation process.

[0026] In this embodiment, the power spindle drive assembly includes a power spindle servo motor 9, model SGD7S-550A, which is a commercially available product. One end of the power spindle servo motor 9 is connected to a master-slave pulley, and a slave pulley is located above the top of the master-slave pulley. A synchronous belt 10 is provided between the master-slave pulley and the slave pulley, and one end of the slave pulley is connected to a spindle box 11. This solution introduces a synchronous belt drive mechanism, utilizing its inherent damping characteristics to effectively block and absorb the torsional vibration and high-frequency harmonics generated during servo motor operation. This flexible transmission method makes the rotational movement of the spindle box 11 smoother and less impactful, greatly improving the rotational accuracy and dynamic stability of the spindle system. This is crucial for achieving mirror-level surface roughness in the "turning instead of grinding" process, preventing tool mark replication caused by spindle vibration.

[0027] In this embodiment, the auxiliary spindle drive assembly includes a machine tool tailstock 19, on which a secondary spindle servo motor 18 is mounted. The secondary spindle servo motor 18 is model HG-SR352B, a commercially available product. A motor protective cover is provided on the outer wall of the secondary spindle servo motor 18, and one end of the secondary spindle servo motor 18 is connected to a tailstock chuck 17. This solution overcomes the limitation of traditional tailstocks only providing passive support, giving the tailstock active driving capability. Through the dual-spindle synchronous drive mode, a force state is formed on the outer ring of the wheel hub bearing, clamping and driving it from both ends, completely changing the problem of insufficient rigidity caused by the long overhang of the workpiece in single-end drive. This significantly enhances the workpiece's resistance to bending and torsion under high-speed cutting, effectively suppresses chatter in workpieces with a large length-to-diameter ratio, and ensures consistent machining accuracy throughout the entire stroke.

[0028] In this embodiment, the drive chuck unit 12 includes a chuck body 37, an annular mounting platform 38, a telescopic hydraulic cylinder, a radial slider 39, a limiting ring 41, a three-jaw chuck, grippers 40, and the outer ring 43 of the wheel hub bearing to be processed, which are sequentially coupled. The chuck body 37 is a cylindrical shell structure with an annular mounting platform 38 on its front end face. The grippers 40 are at least three in number and are evenly distributed on the radial groove surface of the radial slider 39. The limiting ring 41 is an annular structure that is coaxially sleeved on the outer side of the outer circle of the outer ring 43 of the wheel hub bearing to be processed and engages with the inner side of the grippers 40. A positioning rod 42 assembly is provided on one side of the outer wall of the limiting ring 41. This solution addresses the characteristics of the thin-walled and easily deformable outer ring of the wheel hub bearing by adopting a combined clamping strategy of "outer circle limiting + inner support / outer clamping". The limiting ring 41 forms a wrapping constraint on the outer circle of the workpiece, evenly distributing the clamping force and fundamentally avoiding elliptical deformation caused by local stress concentration in thin-walled parts. Meanwhile, the cooperation between the positioning rod 42 assembly and the limiting ring 41 enables the workpiece to be quickly centered and axially positioned, ensuring the repeatability of positioning accuracy during batch processing and solving the functional problems of easy loosening and deviation when the traditional fixture clamps the outer ring of the wheel hub.

[0029] In this embodiment, the tailstock chuck 17 has a tailstock ejector pin 45 at one end, and a flexible ejector pin 44 at the other end. The flexible ejector pin 44 is coaxially disposed at the front end of the tailstock body and mates with the end face of the outer ring 43 of the wheel hub bearing to be processed. This solution introduces an adaptive compensation mechanism. When contacting the end face of the workpiece, the flexible ejector pin 44 can automatically adapt to the micro-unevenness or heat treatment warping of the end face, ensuring that the ejector pin and the end face of the workpiece achieve surface contact or line contact, rather than single-point hard contact. This effectively prevents positioning eccentricity or axial movement caused by defects in the end face of the workpiece, while protecting the end face of the workpiece from being scratched by the hard ejector pin, improving the reliability of workpiece clamping and the quality integrity of the final product.

[0030] In this embodiment, the positioning rod 42 assembly includes a positioning rod 42, which is a rod-shaped structure with a positioning bolt at its front end that mates with the end face of the outer ring of the wheel hub bearing. This solution provides a precise axial positioning reference. By engaging with a preset feature on the end face of the outer ring of the wheel hub bearing, the axial degree of freedom of the workpiece can be quickly eliminated, achieving precise positioning with "one face, one hole". This avoids the cumulative error caused by relying on the chuck clamping length for positioning, significantly improves the angular positioning accuracy of the workpiece in the circumferential direction, and ensures the positional accuracy of features such as oil holes and slots relative to the reference surface.

[0031] In this embodiment, the chain-plate chip conveyor 6 includes an inclined conveyor frame 30, inside which a chain-plate conveying unit is installed. One end of the chain-plate conveying unit is connected to a chain-plate servo motor 31. The chain-plate servo motor 31 is an RV40, a common product available for immediate purchase. One end of the conveyor frame 30 has a feed hopper 29, and the other end has a discharge hopper 33. One end of the discharge hopper 33 has a tilting chip collection cart. The bottom of the conveyor frame 30 has at least two support legs. Transparent splash guards 32 are provided on both sides of the discharge hopper 33. This solution constructs a highly efficient heavy-duty chip conveying channel. The inclined design and chain-plate conveying ensure that high-temperature, heavy steel chips can be quickly removed from the processing area, preventing chip accumulation that could lead to secondary cutting by the tool or equipment damage. The transparent splash guards 32, while allowing operators to observe the chip removal process, also create a physical barrier to prevent cutting fluid and debris from splashing and contaminating the workshop environment, thus improving the cleanliness and safety of equipment operation.

[0032] In this embodiment, the tilting chip collection vehicle includes a hopper 34 for accommodating chips conveyed by a chain-plate chip conveyor 6. The bottom of the hopper 34 is equipped with at least three braked swivel casters 35 and a mounting frame 27. The braked swivel casters 35 are mounted on the bottom of the mounting frame 27. Lifting and tilting mechanisms are provided on both sides of the hopper 34. Each lifting and tilting mechanism includes a cross-link hydraulic unit 36, one end of which is connected to an operating control lever. This solution achieves mechanized handling and unloading of chip collection. Through the hydraulic lifting and tilting mechanism, operators only need to operate the control lever to complete the tilting operation of a heavy-duty car loaded with chips, completely eliminating the labor intensity and safety hazards associated with manually tilting heavy-duty cars. The braked swivel casters 35 ensure the stability and flexibility of the collection vehicle during movement and tilting, optimizing the ergonomic design of factory logistics management.

[0033] In this embodiment, the magnetic separator 5 includes a mounting frame 27, on which a magnetic roller unit 24 is mounted. One end of the magnetic roller unit 24 is connected to a roller servo motor 26. The roller servo motor 26 is a YN90-120 model, a commercially available product. One side of the magnetic roller unit 24 has a water tank 25, and the other side has a chip separation tank 23. The bottom of the water tank 25 has a filter and a cooling water tank 28 connected to its outlet. One end of the cooling water tank 28 is connected to an external water tank 3. This solution establishes a highly efficient solid-liquid separation defense line. The magnetic roller unit 24 automatically adsorbs ferromagnetic fine particles flowing through the cutting fluid, achieving real-time purification and regeneration of the coolant. This effectively prevents tiny metal particles from flowing back into the machining area with the coolant, causing abnormal tool wear or workpiece surface scratches. Maintaining the long-term cleanliness of the coolant not only extends the service life of the cutting fluid but also provides a crucial guarantee for the ultra-clean machining environment required for "turning instead of grinding."

[0034] In this embodiment: Step 1: Pre-clamping preparation and establishment of positioning reference After the operator sets the processing parameters through the operation panel 2, he opens the machine tool door 8 and places the wheel hub bearing outer ring blank to be processed on the limiting ring 41 of the drive chuck unit 12. At this time, the jaws 40 are in a retracted state (leaving a clamping gap of about 1 mm) to ensure that the workpiece can be loaded smoothly. At the same time, the telescopic hydraulic cylinder drives the radial slider 39 to slide along the radial groove, driving at least three jaws 40 to pre-position the inner wall of the workpiece, preparing for subsequent clamping. Step 2: Workpiece clamping and axial positioning The robot grips the workpiece and loads it into the fixture. Then, the chuck body 37 opens, creating a gap of approximately 0.02 to 0.03 mm between the gripper 40 and the limiting ring 41 (coaxially sleeved on the outer side of the workpiece's outer circle) (this gap is within the allowable runout range of the workpiece). Next, the tailstock ejector pin 45 moves forward, pressing the workpiece end face with the flexible ejector pin 44 (installed at the front end of the tailstock body), achieving precise axial positioning of the workpiece. Simultaneously, the positioning bolt at the front end of the positioning rod 42 assembly engages with the preset hole on the workpiece end face, restricting axial sliding of the workpiece and completing omnidirectional positioning of the workpiece. Step 3: Dual-spindle synchronous drive and rigidity reinforcement After the machining is started, the power spindle servo motor 9 of the power spindle drive assembly starts, and the power is transmitted to the auxiliary driven pulley through the main driven pulley and the synchronous belt 10, which ultimately drives the spindle box 11 to rotate. At the same time, the auxiliary spindle servo motor 18 of the auxiliary spindle drive assembly (externally protected by a motor protective cover) starts, and drives the tailstock pin 45 to rotate synchronously through the tailstock chuck 17, so that the outer ring 43 of the wheel hub bearing to be processed forms a high-rigidity, non-overhanging rotary motion under the drive of both ends. Step 4: Precision turning The lead screw drive unit 20 drives the large slide 16 to feed along the guide rail axis of the machine tool bed 22. The turret tool post 13 on the tool post base 15 automatically changes tools according to the machining program and performs hard turning on the outer raceway of the rotating workpiece. During the machining process, the cutting fluid spray pipe 14 continuously sprays coolant to achieve cooling, lubrication and chip removal functions, ensuring that the surface quality of the machined part meets the precision requirements of "turning instead of grinding". Step 5: Separation and recovery of chips and coolant The mixture of chips and cutting fluid generated during processing is flushed to the discharge port 4 and first enters the magnetic separator 5. The mixture flows through the lower water tank 25 to the magnetic roller unit 24. The roller servo motor 26 drives the magnetic roller unit 24 to run. The magnetic roller attracts ferromagnetic chips and transports them to the chip separation tank 23. The separated chips fall into the chain plate chip conveyor 6 below, while the filtered cutting fluid flows back to the cooling water tank 28 (connected to the external water tank 3) through the filter, realizing the recycling of the coolant. Step Six: Chip Conveying and Centralized Collection The chain conveyor unit inside the chain plate type chip conveyor 6 is driven by the chain plate servo motor 31, which conveys the chips upward along the inclined conveyor frame 30 (supported by at least two support feet at the bottom); the chips enter the discharge hopper 33 through the feed hopper 29, and finally fall into the bin 34 of the tilting chip collection vehicle; the transparent splash guards 32 on both sides of the discharge hopper 33 prevent the cutting fluid from splashing, and the universal casters 35 with brakes at the bottom of the tilting chip collection vehicle facilitate movement. Its lifting and tilting mechanism (including the cross-link hydraulic unit 36 ​​and the operating control lever) can realize the tilting unloading of the bin 34; Step 7: Processing Completion and Unloading After processing, the chuck body 37 tightens again, firmly clamping the limit ring 41; the tailstock ejector pin 45 retracts, releasing the axial clamping on the workpiece; the robot grabs the workpiece again and removes the finished product from the drive chuck unit 12, thus completing one complete processing cycle.

[0035] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," 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 the invention. In this specification, 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 may be combined in any suitable manner in one or more embodiments or examples.

[0036] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A turning-based machining equipment for the outer ring of a wheel hub bearing, comprising a lathe body (1), characterized in that... The lathe body (1) includes a machine tool housing (7), an operation panel (2) is connected to one side of the outer wall of the machine tool housing (7), a machine tool door (8) is provided on the outer wall of the machine tool housing (7), a machine tool bed (22) is provided inside the machine tool housing (7), a large slide (16) and a lead screw drive unit (20) for driving the large slide (16) to move axially along the bed guide rail are provided on the machine tool bed (22); a tool post base (15) is provided on one side of the top of the large slide (16), and a rotary tool is connected to one side of the tool post base (15). The tool holder (13) has a cutting fluid spray pipe (14) connected to one side of the tool holder base (15). The tool holder base (15) has a power spindle drive assembly on one side and an auxiliary spindle drive assembly on the other side. The power spindle drive assembly and the auxiliary spindle drive assembly are connected together by a drive chuck unit (12). The machine tool housing (7) has a discharge port (4) on one side and an external water tank (3) on the other side. A magnetic separator (5) is provided at one end of the discharge port (4). A chain plate chip conveyor (6) is connected to one end of the magnetic separator.

2. The wheel hub bearing outer ring machining equipment according to claim 1, characterized in that: The power spindle drive assembly includes a power spindle servo motor (9), one end of which is connected to a main driven wheel, and a secondary driven wheel is provided above the top of the main driven wheel. A synchronous belt (10) is provided between the main driven wheel and the secondary driven wheel, and one end of the secondary driven wheel is connected to a spindle box (11).

3. The wheel hub bearing outer ring machining equipment according to claim 1, characterized in that: The auxiliary spindle drive assembly includes a machine tool tailstock (19), on which a secondary spindle servo motor (18) is mounted. The outer wall of the secondary spindle servo motor (18) is provided with a motor protective cover, and one end of the secondary spindle servo motor (18) is connected to a tailstock chuck (17).

4. The wheel hub bearing outer ring machining equipment according to claim 1, characterized in that: The drive chuck unit (12) includes a chuck body (37), an annular mounting platform (38), a telescopic hydraulic cylinder, a radial slider (39), a limiting ring (41), a three-jaw chuck, grippers (40), and the outer ring (43) of the wheel hub bearing to be processed, which are sequentially connected. The chuck body (37) is a cylindrical shell structure with an annular mounting platform (38) on its front end face. The number of grippers (40) is at least three and they are evenly distributed on the radial groove surface of the radial slider (39). The limiting ring (41) is an annular structure, which is coaxially sleeved on the outer circle of the outer ring (43) of the wheel hub bearing to be processed and cooperates with the inner side of the grippers (40). A positioning rod (42) assembly is provided on one side of the outer wall of the limiting ring (41).

5. The wheel hub bearing outer ring machining equipment according to claim 4, characterized in that: The tailstock chuck (17) has a tailstock pin (45) at one end and a flexible pin (44) at the other end. The flexible pin (44) is coaxially located at the front end of the tailstock body and cooperates with the end face of the outer ring (43) of the wheel hub bearing to be processed.

6. The wheel hub bearing outer ring machining equipment according to claim 4, characterized in that: The positioning rod (42) assembly includes a positioning rod (42), which is a rod-shaped structure with a positioning bolt at its front end that mates with the end face of the outer ring of the wheel hub bearing.

7. The wheel hub bearing outer ring machining equipment according to claim 1, characterized in that: The chain plate chip conveyor (6) includes an inclined conveyor frame (30), inside which a chain plate conveying unit is installed, and one end of the chain plate conveying unit is connected to a chain plate servo motor (31); one end of the conveyor frame (30) is provided with a feed hopper (29), and the other end is provided with a discharge hopper (33); one end of the discharge hopper (33) is provided with a tiltable chip collection cart; the bottom of the conveyor frame (30) is provided with at least two support feet; and transparent splash guards (32) are provided on both sides of the discharge hopper (33).

8. The wheel hub bearing outer ring machining equipment according to claim 1, characterized in that: The tilting chip collection vehicle includes a bin (34) for accommodating chips conveyed by a chain-plate chip conveyor (6); the bottom of the bin (34) is provided with at least three braked swivel casters (35) and a mounting frame (27), the braked swivel casters (35) are mounted on the bottom of the mounting frame (27), and the bin (34) is provided with lifting and tilting mechanisms on both sides, the lifting and tilting mechanisms including a cross-link hydraulic unit (36), one end of the cross-link hydraulic unit (36) is connected to an operating control lever.

9. The wheel hub bearing outer ring machining equipment according to claim 1, characterized in that: The magnetic separator (5) includes a mounting frame (27), on which a magnetic roller unit (24) is provided. One end of the magnetic roller unit (24) is connected to a roller servo motor (26). A water tank (25) is provided on one side of the magnetic roller unit (24), and a chip removal tank (23) is provided on the other side. A filter and a cooling water tank (28) are provided at the bottom of the water tank (25) and connected to the outlet of the water tank (25). One end of the cooling water tank (28) is associated with an external water tank (3).

10. A processing method for a wheel hub bearing outer ring using a turning-instead-of-grinding machining equipment as described in claim 1, characterized in that: Step 1: Pre-clamping preparation and establishment of positioning reference After the operator sets the processing parameters through the operation panel (2), he opens the machine tool door (8) and places the wheel hub bearing outer ring blank to be processed on the limit ring (41) of the drive chuck unit (12). At this time, the jaws (40) are in a tightened state to ensure that the workpiece can be loaded smoothly. At the same time, the telescopic hydraulic cylinder drives the radial slider (39) to slide along the radial groove, driving at least three jaws (40) to pre-position the inner wall of the workpiece to prepare for subsequent clamping. Step 2: Workpiece clamping and axial positioning The robot grips the workpiece and loads it into the fixture. Then, the chuck body (37) opens, creating a gap of about 0.02 to 0.03 mm between the gripper (40) and the limiting ring (41). Next, the tailstock ejector pin (45) moves forward and presses the workpiece end face with the flexible ejector pin (44) installed at the front end of the tailstock body, achieving precise axial positioning of the workpiece. At the same time, the positioning bolt at the front end of the positioning rod (42) assembly engages with the preset hole on the workpiece end face to restrict the axial sliding of the workpiece and complete the all-round positioning of the workpiece. Step 3: Dual-spindle synchronous drive and rigidity reinforcement After the machining is started, the power spindle servo motor (9) of the power spindle drive assembly starts, and the power is transmitted to the auxiliary driven wheel through the main driven wheel and the synchronous belt (10), which finally drives the spindle box (11) to rotate. At the same time, the auxiliary spindle servo motor (18) of the auxiliary spindle drive assembly starts, and drives the tailstock chuck (17) to rotate synchronously, so that the outer ring (43) of the wheel hub bearing to be processed forms a high-rigidity, non-overhanging rotary motion under the drive of both ends. Step 4: Precision turning The lead screw drive unit (20) drives the large slide (16) to feed along the guide rail axis of the machine tool bed (22). The turret tool post (13) on the tool post base (15) automatically changes tools according to the machining program and performs hard turning on the outer raceway of the rotating workpiece. During the machining process, the cutting fluid spray pipe (14) continuously sprays coolant to achieve cooling, lubrication and chip removal functions, ensuring that the machining surface quality meets the precision requirements of turning instead of grinding. Step 5: Separation and recovery of chips and coolant The mixture of chips and cutting fluid generated during processing is flushed to the discharge port (4) and first enters the magnetic separator (5): the mixture flows through the lower water tank (25) to the magnetic roller unit (24), the roller servo motor (26) drives the magnetic roller unit (24) to run, the magnetic roller adsorbs the ferromagnetic chips and transports them to the chip separation tank (23); the separated chips fall into the chain plate chip conveyor (6) below, while the filtered cutting fluid flows back to the cooling water tank (28) through the filter, realizing the recycling of the coolant; Step Six: Chip Conveying and Centralized Collection The chain conveyor unit inside the chain plate chip conveyor (6) is driven by the chain plate servo motor (31) and conveys the chips upward along the inclined conveyor frame (30); the chips enter the discharge hopper (33) through the feed hopper (29) and finally fall into the bin (34) of the tiltable chip collection vehicle; The transparent splash guards (32) on both sides of the discharge hopper (33) prevent the cutting fluid from splashing. The universal casters (35) with brakes at the bottom of the tiltable chip collection vehicle make it easy to move. Its lifting and tilting mechanism includes a cross-link hydraulic unit (36) and an operating control lever to realize the tilting and unloading of the hopper (34). Step 7: Processing Completion and Unloading After processing, the chuck body (37) tightens again, firmly clamping the limit ring (41); the tailstock ejector pin (45) retracts, releasing the axial clamping of the workpiece; the matching robot grabs the workpiece again and removes the finished product from the drive chuck unit (12), thus completing a complete processing cycle.

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