Planetary carrier machining method and finishing device

Abstract

The present application relates to a kind of planet carrier processing method and finish machining device, the processing method includes blank turning, drilling and tapping locking end plate mounting hole, boring and milling planet axle and planet gear lubricating oil hole, drilling planet gear bearing lubricating oil hole, leaving abrasive amount hobbing, chamfering, cleaning, heat treatment carburizing quenching, shot blasting, tempering, hot post-finishing, hot post-finishing boring and milling planet axle, gear grinding and flaw detection;The finish machining device includes self-centering expansion sleeve tension mechanism, auxiliary alignment mechanism, support mechanism.The present application solves the difficulty that carburizing quenching planet carrier exists in the production process, and machining deformation is big, high hardness, high machining precision, when finish machining, planet carrier is simply and conveniently operated by dress clamping, satisfy the high-precision positioning required when planet carrier is finish machining, auxiliary alignment, the machining demand that workpiece dress clamping is conveniently up and down, ensure that the final size precision of planet carrier machining meets the quality requirement.

Description

Technical Field

[0001] This invention relates to a method for machining planetary carriers for gearboxes and a finishing apparatus, belonging to the field of gear machining technology. Background Technology

[0002] With the gradual development of the construction machinery and automotive industries, various unique demands have led to increasingly complex and diversified transmission structures within gearboxes, and the precision requirements for manufacturing various transmission components have also gradually increased, making processing increasingly difficult. For example... Figure 1 The image shows a planetary carrier for an engineering machinery gearbox. Its structure is similar to that of a traditional planetary carrier, but unlike traditional planetary carriers which are mostly made of 42CrMo quenched and tempered material, this one is made of 20CrMnTi material and requires carburizing and quenching heat treatment. Therefore, it has the challenges of large deformation, high hardness and high precision after heat treatment. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a planetary carrier machining method to solve the difficulties of large deformation, high hardness, and high precision in the production of 20CrMnTi planetary carriers. At the same time, it also provides a planetary carrier finishing device to meet the machining requirements of high-precision positioning, auxiliary alignment, and convenient workpiece clamping during the finishing of planetary carriers. The machining operation is simple and ensures the consistency of workpiece machining accuracy, large-scale repeated machining of workpieces, and automated clamping status.

[0004] The objective of this invention is achieved as follows: A method for machining a planetary carrier includes the following machining steps: A. Turning of the blank: A1. Using a turning center, a three-jaw chuck is used to hold the three evenly distributed planetary shafts of the planetary carrier. The planetary carrier's inner hole, outer circle, and end face are turned with the planetary carrier's open side facing the flat end face. A2. When turning the second face of the planetary carrier, the soft jaws support the positioning datum position after heat treatment and finishing; turn the first face at the corresponding position, leaving a machining allowance for finishing after heat treatment. B. Drilling and tapping the locking end plate mounting holes: Machining the planetary carrier end face mounting holes and drilling angled oil holes; C. Drilling, boring, and milling the lubrication holes of the planetary shaft and planetary gears; D. Drill the lubrication oil hole for the planetary gear bearing; E. Leave a grinding allowance when hobbing gears; F. Chamfering: Processed using a special gear chamfering machine; G. Cleaning: Thoroughly clean to remove cutting fluid and oil from the outer diameter and root end face of the planetary shaft; prevent defects caused by the anti-seepage coating treatment at the corresponding heat treatment locations. H. Heat treatment: carburizing and quenching: the outer circle and root end face of the planetary shaft are required to be coated with an anti-seepage coating for anti-seepage treatment. I. Shot blasting: Removes impurities from the surface of the workpiece; J. Tempering: Low-temperature tempering eliminates heat treatment stress in parts and reduces deformation caused by stress release during post-heat finishing. K. Finishing after heating: K1. The calibration datum for hard turning of the planetary carrier is to use a hard turning center, hard turning the first face of the planetary carrier and using a hook-head turning tool to machine the second face, and then fine boring and milling of the planetary shaft and grinding after hot turning. K2, the positioning method is the same as that of turning the second side of the A2 blank, and the corresponding finishing position is hard-turned; L. Precision boring and milling of planetary shafts after hot machining: The planetary carrier, after being precision turned in process K, is positioned, calibrated, and clamped using a precision machining device before precision boring and milling of the planetary shafts. M. Gear grinding: The planetary carrier is corrected and clamped using a precision machining device, and then gear grinding is performed. N. Flaw detection: Flaw detection shall be performed on the surface and near-surface of the parts, and there shall be no defects in finishing processes such as heat treatment and grinding.

[0005] Furthermore, during the blank turning process A1, the external tooth tip is turned together with the positioning datum and correction datum of the A2 turning process to ensure that the end face runout is no greater than 0.02mm and the coaxiality of the outer circle and inner hole is no greater than 0.02mm.

[0006] Furthermore, in process A2, the machining allowance for the first surface after heat treatment shall not be less than 0.2 mm; the correction datum for the turning process of A2 shall not be greater than 0.03 mm.

[0007] Furthermore, the mounting holes and inclined oil holes in process B are machined using a special drilling jig and an optional angled radial drilling table. The drilling jig guides the machining of the mounting holes. After rotating the angle, the inclined oil holes are drilled according to the inclined hole guide on the drilling jig, ensuring that the inclined oil holes completely penetrate the oil groove when the blank is turned on the first surface.

[0008] Furthermore, in process C, the positioning datum for boring and milling the planetary shaft is consistent with the second surface of the blank being turned, requiring the alignment of the tooth tip circle to be hobbed to within 0.01mm; for drilling, boring, and milling the lubricating oil holes of the planetary shaft and planetary gears, the inner hole of the calibration datum should not exceed 0.03mm, and the end face should not exceed 0.03mm.

[0009] Furthermore, in process D, the lubricating oil hole of the planetary gear bearing is a long inclined hole, which is drilled after the planetary shaft is corrected using a five-axis vertical machining center. The positional deviation of the corrected planetary shaft is no more than 0.05mm, and it is required to completely penetrate the oil groove machined on the second surface of the blank.

[0010] Furthermore, in process E, the positioning datum for the hobbing gear with the allowance of the planetary carrier is consistent with the second surface of the blank being turned, requiring the alignment of the tooth tip circle to be hobbed to within 0.01mm, and the allowance for the common normal to be hobbed to be 0.25mm on each side.

[0011] Furthermore, the controlled anti-seepage location in process H must not have a carburized layer with a depth exceeding 0.2 mm, and the hardness of the controlled anti-seepage location after carburizing and quenching should be lower than 45 HRC.

[0012] Furthermore, the tempering process in step J ensures that the hardness of the planetary carrier at the finishing boring and milling position after hot machining does not exceed 45 HRC.

[0013] Furthermore, in the process K, the positioning method of the first surface after hot finishing is the same as that of the first surface of the A1 blank, and the positioning method of the second surface is the same as that of the first surface of the A2 blank. The corresponding finishing positions are hard-machined to ensure that the end face runout is no more than 0.01mm and the coaxiality of the inner hole and outer circle is no more than 0.01mm.

[0014] Furthermore, process L employs a planetary carrier-specific precision machining device, utilizing the inner hole after precision machining for positioning, and a self-centering expansion sleeve for tightening, ensuring that the calibration datum is consistent with the second surface after heat machining; the outer diameter runout is corrected to be no greater than 0.015mm; the end face runout is corrected to be no greater than 0.015mm.

[0015] Furthermore, the gear grinding process M uses a planetary carrier-specific precision machining device, and the calibration benchmark is consistent with the second surface after hot turning and the planetary shaft after hot boring and milling; the outer circle runout is calibrated to be no more than 0.015mm; the end face runout is calibrated to be no more than 0.015mm.

[0016] A planetary carrier finishing device is applied to any of the above-mentioned planetary carrier machining methods to realize the positioning, calibration and clamping of the workpiece during planetary carrier machining, including a self-centering expansion sleeve tensioning mechanism, an auxiliary alignment mechanism and a support mechanism. The support mechanism includes a base plate, an end-face support positioning ring fixed to the front of the base plate, a positioning mandrel installed on the bottom surface of the base plate, and a clamping mechanism. The end-face support positioning ring provides support for the bottom surface of the planetary carrier. The positioning mandrel cooperates with the pin hole on the machine tool worktable to determine the center of the overall tooling of the finishing device, ensuring repeatability and positioning accuracy. The clamping mechanism presses down on the top surface of the planetary carrier and cooperates with the end-face support positioning ring to clamp and limit the axial movement of the planetary carrier. The self-centering expansion sleeve tensioning mechanism includes a self-centering expansion sleeve fixed on the base plate, a movable mandrel that is movably and vertically disposed within the central hole of the expansion sleeve, an elastic element disposed between the movable mandrel and the base plate, a clamping bolt disposed within the central hole of the movable mandrel for controlling the amount of compression of the movable mandrel, and an adjusting stroke positioning ring that is locked from the back of the base plate to the bottom of the clamping bolt by an adjusting bolt. The outer circumference of the movable mandrel is provided with an inclined surface that mates with the inner hole of the expansion sleeve. The vertical displacement of the movable mandrel controls the expansion amount of the expansion sleeve. The vertical displacement of the movable mandrel is achieved by rotating the adjusting bolt to control the vertical stroke of the clamping bolt, thereby controlling the vertical displacement of the movable mandrel and thus controlling the expansion amount of the expansion sleeve, thereby achieving the positioning and radial tensioning of the planetary carrier. The auxiliary alignment mechanism consists of an angular positioning seat fixed to the base plate, an angular slider horizontally slidable on the angular positioning seat, an angular V-block installed at the left end of the angular slider, a pull rod installed at the right end of the angular slider, and a horizontal compression spring fitted on the angular slider between the angular positioning seat and the pull rod. A hinge mechanism is installed between the angular positioning seat and the pull rod to control the angular slider to move horizontally axially. The angular V-block extends horizontally and contacts one of the planetary shafts of the planetary carrier to achieve angular positioning.

[0017] Furthermore, the clamping mechanism comprises three sets, evenly distributed around the circumference of the planetary carrier, including a support column and a double-ended stud respectively fixed to the base plate, a pressure plate movably fitted onto the double-ended stud in the middle, and a vertical compression spring fitted onto the double-ended stud and pressing against the bottom of the pressure plate; the left end of the pressure plate is mounted on the top of the support column, and the bottom of the right end is fitted with a pressure head that contacts the planetary carrier; a hexagonal flange nut is screwed onto the threaded top of the double-ended stud for adjusting the vertical position of the pressure plate.

[0018] Furthermore, the elastic element is a butterfly spring; a limit bolt is horizontally screwed onto the side of the expansion sleeve to limit the axial displacement of the movable spindle.

[0019] Furthermore, the hinge mechanism includes a hinge seat mounted on an angular positioning seat and a lever arm hinged to a pull rod in the middle via a pin; one end of the hinge seat and the lever arm are movably connected to a hinge plate via a pin.

[0020] Compared with the prior art, the beneficial effects of the present invention are: This invention discloses a planetary carrier machining method. Addressing the challenges of large deformation, high hardness, and high precision during the production of planetary carriers made of 20CrMnTi material, the method employs a 14-step machining process: A) blank turning; B) drilling and tapping locking end plate mounting holes; C) drilling, boring, and milling planetary shafts and planetary gear lubrication holes; D) drilling planetary gear bearing lubrication holes; E) gear hobbing with allowance; F) chamfering; G) cleaning; H) heat treatment carburizing and quenching; I) shot blasting; J) tempering; K) post-heat finishing turning; L) post-heat finishing boring and milling of planetary shafts; M) gear grinding; and N) flaw detection. The processes are designed to be mutually coordinated and rationally integrated. The method specifies the machining precision and corresponding requirements for each step, ensuring that the final dimensional accuracy of the planetary carrier meets quality requirements. This invention discloses a planetary carrier precision machining device. By setting up a self-centering expansion sleeve tensioning mechanism, an auxiliary alignment mechanism, and a support mechanism, it realizes the positioning, calibration, and clamping of the workpiece during precision machining. The planetary carrier clamping operation is simple and convenient. During the clamping process, calibration and positioning are automatically achieved, meeting the high-precision positioning, auxiliary alignment, and convenient workpiece clamping requirements of planetary carriers during precision machining. The machining operation is simple, ensuring the workpiece machining accuracy, the consistency of workpiece batch repetitive machining, and the automated clamping state. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the planetary carrier structure involved in the present invention.

[0022] Figure 2 This invention relates to a process flow diagram of a planetary carrier machining method.

[0023] Figure 3 This is a front cross-sectional structural diagram of a planetary carrier finishing device according to the present invention.

[0024] Figure 4 This is a top view schematic diagram of a planetary carrier finishing apparatus according to the present invention.

[0025] Figure 5 This is a schematic diagram of a partial cross-sectional structure of a planetary carrier finishing device according to the present invention.

[0026] Figure 6 This is a schematic diagram of a partial cross-sectional structure of a planetary carrier finishing device according to the present invention.

[0027] Figure 7 This is a schematic diagram of the expansion sleeve structure of a planetary carrier precision machining device according to the present invention.

[0028] Figure 8 This is a schematic diagram of the base plate structure of a planetary carrier precision machining device according to the present invention.

[0029] Figure 9 This is a schematic diagram of the lever arm structure of a planetary carrier finishing device according to the present invention.

[0030] in: 1. Base plate; 2. Ventilation bolt; 3. End face support positioning ring; 4. Expansion sleeve; 5. Movable spindle; 6. Elastic element; 7. Limit bolt; 8. Clamping bolt; 9. Adjusting stroke positioning ring; 10. Adjusting bolt; 11. Sealing ring; 12. Angular slider; 13. Angular V-block; 14. Angular positioning seat; 15. Positioning spindle; 16. Hinge seat; 27. Hinge plate; 28. Lever arm; 29. ​​Pull rod; 20. Horizontal compression spring; 21. Pressure plate; 22. Pressure head; 33. Support column; 34. Double-ended stud; 35. Hexagonal flange nut; 36. Vertical compression spring. Implementation

[0031] See Figures 1-2 The present invention relates to a method for machining a planetary carrier, comprising the following machining steps: A. Turning of the blank: A1. Using a turning center, a three-jaw chuck holds the three evenly distributed planetary shafts of the planetary carrier. The end faces of the three planetary shafts are aligned with the center. The first face of the planetary carrier, including the end face of the open-side outer circle and inner hole, as well as the open-side inner hole and outer circle, are turned. When turning the blank in A1, it is necessary to ensure that the tooth tip of the outer tooth is turned together with the positioning datum and correction datum of the A2 turning process. At the same time, it should be ensured that the end face runout is not greater than 0.02mm and the coaxiality of the outer circle and inner hole is not greater than 0.02mm. A2. When turning the second face of the planetary carrier, i.e. the end face of the planetary shaft, the soft jaws are used to support the positioning datum position after heat treatment and finishing. The corresponding position is turned on the first face, leaving a machining allowance of not less than 0.2mm after heat treatment and finishing. The correction datum for the A2 turning process is not greater than 0.03mm. B. Drilling and tapping the mounting holes of the locking end plate: Machining the mounting holes and inclined oil holes on the end face of the planetary carrier; the inclined oil hole is machined using a special drilling jig and an optional angled radial drilling table. The drilling jig guides the machining of the bottom hole of the threaded hole, i.e., the mounting hole; after the radial drilling rotates to the desired angle, the inclined oil hole is drilled according to the inclined hole guide on the drilling jig, ensuring that the inclined oil hole and the oil groove are completely connected when the blank is turned on the first surface. C. Drill, bore, and mill the lubricating oil holes of the planetary shaft and planetary gears; the positioning datum for boring and milling the planetary shaft is consistent with the second surface of the blank being turned, and the alignment of the addendum circle of the gear to be hobbed is required to be within 0.01mm; for drilling, boring, and milling the lubricating oil holes of the planetary shaft and planetary gears, the inner hole of the datum should be no greater than 0.03mm, and the end face should be no greater than 0.03mm. D. Drill the lubricating oil hole of the planetary gear bearing; the lubricating oil hole of the planetary gear bearing is a long inclined hole. After the planetary shaft is corrected by a five-axis vertical machining center, it is drilled. It is required to completely penetrate the oil groove machined on the second surface of the blank. The positional deviation of the corrected planetary shaft is not greater than 0.05mm. E. Gear hobbing with grinding allowance; The positioning datum for gear hobbing with grinding allowance of planetary carrier is consistent with the second surface of blank turning. It is required to align the tooth tip circle to be hobbed within 0.01mm, and the grinding allowance of the common normal is 0.25mm on one side. F. Chamfering: Processed using a special gear chamfering machine; G. Cleaning: Thoroughly clean to remove cutting fluid and oil from the outer diameter and root end face of the planetary shaft; prevent defects caused by the anti-seepage coating treatment at the corresponding heat treatment locations. H. Heat treatment: carburizing and quenching: the outer diameter and root end face of the planetary shaft must be coated with anti-seepage paint; the depth of the carburized layer at the anti-seepage location must not exceed 0.2mm, and the hardness at the anti-seepage location after carburizing and quenching should be lower than 45HRC; ensure that the anti-seepage treatment at the boring and milling location of the planetary carrier after hot finishing is not greater than 0.2mm. I. Shot blasting: Removes impurities from the surface of the workpiece; after shot blasting, no impurities are left on the surface of the parts. J. Tempering: Low-temperature tempering eliminates heat treatment stress in parts and reduces deformation caused by stress release during post-heat finishing; tempering treatment ensures that the hardness of the planetary carrier at the boring and milling position after post-heat finishing is not greater than 45HRC; K. Finishing after heating: K1. Use a hard turning center, with the positioning method the same as the first face of the A1 blank. Hard turn the corresponding finishing position and use a hook-head cutting tool to machine the second face of the hard turn, and then perform a correction datum for the planetary shaft and gear grinding process after hot finishing. K2, the positioning method is the same as that of turning the second side of the A2 blank, and the corresponding finishing position is hard turned; after hot finishing, it is required to ensure that the end face runout is not greater than 0.01mm; the coaxiality of the inner hole and outer circle is not greater than 0.01mm; L. Post-heat finish precision boring and milling of planetary shafts: After the planetary carrier has been precision turned in process K, it is positioned, calibrated, and clamped using a precision machining device. The planetary shaft is then precision-milled using the precision-turned inner hole. The self-centering expansion sleeve is tightened, and the calibration datum is kept consistent with the second surface after heat finish turning. The outer diameter runout is corrected to be no more than 0.015mm. The end face runout is corrected to be no more than 0.015mm. M. Gear Grinding: The planetary carrier is aligned and clamped using a precision machining device, and then gear grinding is performed. A dedicated precision machining device for the planetary carrier is used, and the alignment datum is kept consistent with the second face after hot turning and the planetary shaft after hot boring and milling. The external cylindrical runout is corrected to be no greater than 0.015mm; the end face runout is corrected to be no greater than 0.015mm. N. Flaw detection: Using ultrasonic testing, magnetic particle testing or eddy current testing methods, flaw detection is performed on the surface and near-surface of the parts. There must be no defects in the finishing process such as heat treatment and grinding.

[0032] The planetary carrier machining method of this invention addresses the challenges of large deformation, high hardness, and high precision during the production of planetary carriers made of 20CrMnTi material. It designs a machining process comprising fourteen steps: A. blank turning; B. drilling and tapping locking end plate mounting holes; C. drilling, boring, and milling planetary shafts and planetary gear lubrication holes; D. drilling planetary gear bearing lubrication holes; E. hobbing with grinding allowance; F. chamfering; G. cleaning; H. heat treatment carburizing and quenching; I. shot blasting; J. tempering; K. post-heat finishing turning; L. post-heat finishing boring and milling of planetary shafts; M. gear grinding; and N. flaw detection. The steps are designed to be mutually coordinated and have reasonable specifications. The machining precision and corresponding requirements for each step are specified to ensure that the final dimensional accuracy of the planetary carrier meets the quality requirements.

[0033] On the other hand, see Figures 3-9 The present invention relates to a planetary carrier finishing device, which is applied in the above-mentioned planetary carrier machining method to realize the positioning, calibration and clamping of the workpiece during finishing, and further ensure the finishing accuracy. It includes a self-centering expansion sleeve tensioning mechanism, an auxiliary alignment mechanism and a support mechanism. The support mechanism includes a base plate 1, an end-face support positioning ring 3 fixed to the front of the base plate 1, a positioning mandrel 20 installed on the bottom surface of the base plate 1, and a clamping mechanism. The end-face support positioning ring 3 provides support for the bottom surface of the planetary carrier. A sealing ring 13 is installed on the end-face support positioning ring 3 for dust prevention. The positioning mandrel 20 cooperates with the pin hole on the machine tool worktable to determine the center of the overall tooling of the finishing device, ensuring repeatability and positioning accuracy. There are three sets of clamping mechanisms, evenly distributed around the circumference of the planetary carrier, pressing down on the top surface of the planetary carrier and cooperating with the end-face support positioning ring 3 to axially support the planetary carrier. Clamping and limiting; the clamping mechanism includes a support column 31 and a double-ended stud 32 respectively fixed on the base plate 1, a pressure plate 29 movably fitted on the double-ended stud 32 in the middle, and a vertical compression spring 35 fitted on the double-ended stud 32 and pressing against the bottom of the pressure plate 29; the left end of the pressure plate 29 is mounted on the top of the support column 31, and the bottom of the right end is equipped with a pressure head 30 that contacts the planetary carrier; a hexagonal flange nut 34 is screwed onto the thread on the top of the double-ended stud 32 for adjusting the up and down position of the pressure plate 29. Rotating the hexagonal flange nut 34 will press the pressure plate 29 down so that the pressure head 30 can press against the planetary carrier; The self-centering expansion sleeve tensioning mechanism includes a self-centering expansion sleeve 5 fixed on the base plate 1, a movable spindle 7 movably disposed in the center hole of the expansion sleeve 5, an elastic element 8 disposed between the movable spindle 7 and the base plate 1, a clamping bolt 10 disposed in the center hole of the movable spindle 7 for controlling the amount of compression of the movable spindle 7, and an adjusting stroke positioning ring 11 locked from the back of the base plate 1 to the bottom of the clamping bolt 10 by adjusting bolt 12; the elastic element 8 is a butterfly spring, which lifts the movable spindle 7 upward to a normally open state, and the clamping bolt 10 and the butterfly spring cooperate to axially lock the movable spindle 7, and the vertical displacement of the movable spindle 7 can be achieved by controlling the axial displacement of the clamping bolt 10; the expansion sleeve 5 is horizontally rotated on the side. A limiting bolt 9 is provided, the end of which is engaged in a limiting groove on the movable spindle 7 to limit the axial displacement range of the movable spindle 7. The bottom of the movable spindle 7 is connected to the atmosphere through a pipe and a vent bolt 2 set inside the base plate 1 to eliminate the air pressure obstruction caused by the vertical displacement of the movable spindle 7. The vent bolt 2 serves to allow air to pass through and prevent dust. The outer circumference of the movable spindle 7 is provided with an inclined surface that mates with the inner hole of the expansion sleeve 5. The vertical displacement of the movable spindle 7 can control the expansion amount of the expansion sleeve 5. The vertical displacement of the movable spindle 7 can be controlled by rotating the adjusting bolt 12 to control the vertical stroke of the clamping bolt 10, thereby realizing the vertical displacement of the movable spindle 7 and controlling the expansion amount of the expansion sleeve 5, thus realizing the positioning and radial tightening of the planetary carrier. The auxiliary alignment mechanism consists of an angular positioning seat 17 fixed on the base plate 1, an angular slider 14 horizontally slidably mounted on the angular positioning seat 17, an angular V-block 15 mounted on the left end of the angular slider 14, a pull rod 26 mounted on the right end of the angular slider 14, and a horizontal compression spring 28 fitted on the angular slider 14 between the angular positioning seat 17 and the pull rod 26. A hinge mechanism is installed between the angular positioning seat 17 and the pull rod 26 to control the angular slider 14 to move horizontally axially. The angular V-block 15 extends horizontally and contacts one planetary shaft of the planetary carrier to achieve angular positioning. The hinge mechanism includes a hinge seat 22 mounted on the angular positioning seat 17 and a lever arm 25 hinged to the pull rod 26 in the middle by a pin. One end of the hinge seat 22 and the lever arm 25 are movably connected to the hinge plate 24 by a pin.

[0034] When machining the planetary carrier, first, the base plate 1 of the support mechanism is aligned with the pin hole on the machine tool table via the positioning mandrel 20 to determine the center of the overall tooling of the finishing device in this embodiment of the invention, ensuring repeatability and positioning accuracy. The planetary carrier is fitted onto the expansion sleeve 5 with the planetary shaft side facing upwards and the open side facing upwards. The adjusting bolt 12 is rotated to retract the expansion sleeve 5, ensuring the planetary carrier falls smoothly and contacts the end face support positioning ring 3 of the support mechanism. The pressure head 30 of the clamping mechanism is initially pressed against the top surface of the planetary carrier. The lever arm 25 is pushed to extend the angular V-block 15 horizontally to contact one of the planetary shafts of the planetary carrier, causing the planetary carrier to rotate and achieve angular positioning. The adjusting bolt 12 is rotated to open the expansion sleeve 5, utilizing the alignment of the expansion sleeve 5's axis with the tooling center to achieve positioning and radial clamping of the planetary carrier. The clamping mechanism is then used to clamp the planetary carrier, completing the clamping process. After finishing, the workpiece can be quickly removed by reversing the operation.

[0035] The planetary carrier finishing device of the present invention is simple and convenient for planetary carrier clamping operation. It automatically realizes calibration and positioning during the clamping process, which meets the high-precision positioning, auxiliary alignment and convenient workpiece clamping required for planetary carrier finishing. The processing operation is simple, ensuring the workpiece processing accuracy, the consistency of workpiece batch repetitive processing and automated clamping status.

[0036] Additionally, it should be noted that the above-described specific implementation is merely an optimized solution of this patent, and any modifications or improvements made by those skilled in the art based on the above concept are within the scope of protection of this patent.

Claims

1. A method for machining a planetary carrier, characterized in that: It includes the following processing steps: A. Turning of the blank: A1. Using a turning center, a three-jaw chuck is used to hold the three evenly distributed planetary shafts of the planetary carrier. The planetary carrier's inner hole, outer circle, and end face are turned with the planetary carrier's open side facing the flat end face. A2. When turning the second face of the planetary carrier, the soft jaws support the positioning datum position after heat treatment and finishing; turn the first face at the corresponding position, leaving a machining allowance for finishing after heat treatment. B. Drilling and tapping the locking end plate mounting holes: Machining the planetary carrier end face mounting holes and drilling angled oil holes; C. Drilling, boring, and milling the lubrication holes of the planetary shaft and planetary gears; D. Drill the lubrication oil hole for the planetary gear bearing; E. Leave a grinding allowance when hobbing gears; F. Chamfering: Processed using a special gear chamfering machine; G. Cleaning: Thoroughly clean to remove cutting fluid and oil from the outer diameter and root end face of the planetary shaft; prevent defects caused by the anti-seepage coating treatment at the corresponding heat treatment locations. H. Heat treatment: carburizing and quenching: the outer circle and root end face of the planetary shaft are required to be coated with an anti-seepage coating for anti-seepage treatment. I. Shot blasting: Removes impurities from the surface of the workpiece; J. Tempering: Low-temperature tempering eliminates heat treatment stress in parts and reduces deformation caused by stress release during post-heat finishing. K. Finishing after heating: K1. The calibration datum for hard turning of the planetary carrier is to use a hard turning center, hard turning the first face of the planetary carrier and using a hook-head turning tool to machine the second face, and then fine boring and milling of the planetary shaft and grinding after hot turning. K2, the positioning method is the same as that of turning the second side of the A2 blank, and the corresponding finishing position is hard-turned; L. Precision boring and milling of planetary shafts after hot machining: The planetary carrier, after being precision turned in process K, is positioned, calibrated, and clamped using a precision machining device before precision boring and milling of the planetary shafts. M. Gear grinding: The planetary carrier is corrected and clamped using a precision machining device, and then gear grinding is performed. N. Flaw detection: Flaw detection shall be performed on the surface and near-surface of the parts, and there shall be no defects in heat treatment and finishing.

2. The planetary carrier machining method according to claim 1, characterized in that: During the blank turning process A1, ensure that the tip of the external tooth is turned together with the positioning datum and correction datum of the turning process A2, and ensure that the end face runout is no more than 0.02mm and the coaxiality of the outer circle and inner hole is no more than 0.02mm.

3. The planetary carrier machining method according to claim 1, characterized in that: In process A2, the machining allowance for the first surface after heat treatment shall not be less than 0.2 mm; the correction datum for the turning process of A2 shall not be greater than 0.03 mm.

4. The planetary carrier machining method according to claim 1, characterized in that: The mounting holes and inclined oil holes in process B are machined using a special drilling jig and an angled radial drilling table. The drilling jig guides the machining of the mounting holes. After rotating the angle, the inclined oil holes are drilled according to the guide of the inclined holes on the drilling jig, ensuring that the inclined oil holes completely penetrate the oil groove when the blank is turned on the first surface.

5. The planetary carrier machining method according to claim 1, characterized in that: In process C, the positioning datum for boring and milling the planetary shaft is consistent with the second surface of the blank being turned, requiring the alignment of the addendum circle of the gear to be hobbed to be within 0.01mm; for drilling, boring, and milling the lubricating oil holes of the planetary shaft and planetary gears, the inner hole of the datum should be no greater than 0.03mm, and the end face should be no greater than 0.03mm.

6. The planetary carrier machining method according to claim 1, characterized in that: In process D, the lubricating oil hole of the planetary gear bearing is a long inclined hole. After the planetary shaft is corrected by a five-axis vertical machining center, it is drilled. The positional deviation of the corrected planetary shaft is no more than 0.05mm. It is required to completely penetrate the oil groove machined on the second surface of the blank.

7. The planetary carrier machining method according to claim 1, characterized in that: In process E, the grinding allowance of the planetary carrier and the positioning datum for gear hobbing are consistent with the second surface of the blank being turned. It is required that the tooth tip circle to be hobbed be aligned within 0.01mm, and the grinding allowance on the common normal is 0.25mm on each side.

8. The planetary carrier machining method according to claim 1, characterized in that: In process H, the controlled anti-seepage location must not have a carburized layer with a depth exceeding 0.2 mm, and the hardness of the controlled anti-seepage location should be lower than 45 HRC after carburizing and quenching.

9. The planetary carrier machining method according to claim 1, characterized in that: The tempering process J ensures that the hardness of the planetary carrier at the finishing boring and milling position after hot machining does not exceed 45 HRC.

10. The planetary carrier machining method according to claim 1, characterized in that: The positioning method for the first surface of the hot-turned finish machining process K is the same as that for the first surface of the A1 blank, and the positioning method for the second surface is the same as that for the first surface of the A2 blank. The corresponding finishing positions are then hard-turned to ensure that the end face runout is no greater than 0.01mm and the coaxiality of the inner hole and outer circle is no greater than 0.01mm.

11. The planetary carrier machining method according to claim 1, characterized in that: The process L uses a planetary carrier-specific precision machining device, which uses the inner hole after precision machining for positioning, and a self-centering expansion sleeve for tightening. The calibration datum is consistent with the second surface after heat machining; the outer circle runout is corrected to be no more than 0.015mm; the end face runout is corrected to be no more than 0.015mm.

12. The planetary carrier machining method according to claim 1, characterized in that: The gear grinding process M uses a planetary carrier-specific precision machining device. The calibration benchmark is consistent with the second surface after hot turning and the planetary shaft after hot boring and milling. The outer circle runout is calibrated to be no more than 0.015mm. The end face runout is calibrated to be no more than 0.015mm.

13. A planetary carrier finishing apparatus, applied in any one of the planetary carrier machining methods according to claims 1 to 12, for positioning, calibrating, and clamping the workpiece during planetary carrier machining, characterized in that: It includes a self-aligning tightening mechanism, an auxiliary alignment mechanism, and a support mechanism; The support mechanism includes a base plate (1), an end face support positioning ring (3) fixed on the front of the base plate (1), a positioning mandrel (20) installed on the bottom surface of the base plate (1), and a clamping mechanism; the end face support positioning ring (3) is used to provide support for the bottom surface of the planetary carrier; the positioning mandrel (20) cooperates with the pin hole on the machine tool worktable to determine the center of the overall tooling of the finishing device, ensuring repeatability positioning accuracy; the clamping mechanism presses down on the top surface of the planetary carrier, and cooperates with the end face support positioning ring (3) to clamp and limit the axial movement of the planetary carrier. The self-centering expansion sleeve tensioning mechanism includes a self-centering expansion sleeve (5) fixed on the base plate (1), a movable spindle (7) movably disposed in the center hole of the expansion sleeve (5), an elastic element (8) disposed between the movable spindle (7) and the base plate (1), a clamping bolt (10) disposed in the center hole of the movable spindle (7) for controlling the amount of compression of the movable spindle (7), and an adjustment stroke positioning ring (11) locked from the back of the base plate (1) to the bottom of the clamping bolt (10) by an adjusting bolt (12); the outer circumference of the movable spindle (7) is provided with an inclined surface that matches the inner hole of the expansion sleeve (5), and the up and down displacement of the movable spindle (7) can control the amount of expansion of the expansion sleeve (5); by rotating the adjusting bolt (12) to control the up and down stroke of the clamping bolt (10), the up and down displacement of the movable spindle (7) is realized, thereby controlling the amount of expansion of the expansion sleeve (5), thereby realizing the positioning and radial tensioning of the planetary carrier; The auxiliary alignment mechanism is fixed on the base plate (1) with an angular positioning seat (17), an angular slider (14) horizontally slidably disposed on the angular positioning seat (17), an angular V-block (15) installed on the left end of the angular slider (14), a pull rod (26) installed on the right end of the angular slider (14), and a horizontal compression spring (28) fitted on the angular slider (14) between the angular positioning seat (17) and the pull rod (26); a hinge mechanism is installed between the angular positioning seat (17) and the pull rod (26) to control the angular slider (14) to move horizontally in the axial direction, and the angular V-block (15) extends horizontally to contact one of the planetary shafts of the planetary carrier to achieve angular positioning.

14. The planetary carrier finishing apparatus according to claim 13, characterized in that: The clamping mechanism consists of three sets, evenly distributed around the circumference of the planetary carrier. Each set includes a support column (31) and a double-ended stud (32) fixed on the base plate (1), a pressure plate (29) movably mounted on the double-ended stud (32) in the middle, and a vertical compression spring (35) mounted on the double-ended stud (32) and pressing against the bottom of the pressure plate (29). The left end of the pressure plate (29) is mounted on the top of the support column (31), and the bottom of the right end is fitted with a pressure head (30) that contacts the planetary carrier. A hexagonal flange nut (34) is screwed onto the threaded top of the double-ended stud (32) to adjust the vertical position of the pressure plate (29).

15. The planetary carrier finishing apparatus according to claim 13, characterized in that: The elastic element (8) is a butterfly spring; a limit bolt (9) is horizontally screwed on the side of the expansion sleeve (5) to limit the axial displacement of the movable spindle (7).

16. The planetary carrier finishing apparatus according to claim 13, characterized in that: The hinge mechanism includes a hinge seat (22) mounted on an angular positioning seat (17) and a lever arm (25) hinged in the middle to a pull rod (26) via a pin; one end of the hinge seat (22) and the lever arm (25) are movably connected to a hinge plate (24) via a pin.

Images