A method and special fixture for milling a planetary gear spherical eccentric ring-shaped oil groove

Abstract

The application discloses a kind of planetary gear spherical eccentric ring-like oil groove milling method and special fixture, belong to mechanical processing technical field. Including base, shaft, adjusting screw, flange assembly, tooth mould, pressing plate, tool bit, cutter head and the special fixture of tool bar, wherein the outer spherical surface of flange assembly is built into the inner spherical surface of base to form spherical surface cooperation;Rotary adjusting screw adjusts the included angle of flange assembly and base to the eccentric angle of workpiece;Through hydraulic expansion mechanism oil cavity, oil channel, oil cylinder, spring, piston, adjusting bolt, flange assembly is rigidly locked with base;After clamping workpiece, workpiece is relatively rotated with tool bit and simultaneously axial feed is completed milling.The application can be applied to lathe or drilling machine and the like general equipment, has the advantages of more than doubling efficiency, strong universality without special equipment, quick change time is one half of original, low cost single piece reduction and the like.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, specifically relating to a method for milling eccentric annular oil grooves on the spherical surface of planetary gears and a special fixture. Background Technology

[0002] Planetary gears are a core component of differentials, transmitting and distributing torque during operation, resulting in complex working conditions. Insufficient lubrication often leads to sintering or annealing of planetary gears, causing functional failure. To address this issue, existing technology adds an eccentric annular oil groove to the spherical surface of the planetary gear. This allows for smoother replenishment and exchange of lubricating oil. One side of the annular groove intersects with the chamfer of the inner bore and communicates with it, while the other side slightly extends beyond the diameter of the spherical crown, forming an oil passage. This allows lubricating oil to flow through, carrying away heat between the planetary gear and the spherical gasket, and also facilitates the formation of an oil film between the spherical surface and the gasket, reducing friction and lowering the risk of gear failure.

[0003] Currently, there are two main methods for processing this eccentric annular oil groove:

[0004] The first method involves machining with a machining center, programming the eccentric shape and position, and then machining with a vertical milling cutter. This process can perfectly machine eccentric annular oil grooves with high precision, but it suffers from drawbacks such as low efficiency, high cost, and high tool wear, making it unsuitable for large-scale production.

[0005] The second method involves machining on a CNC lathe, using an eccentric gear mold fixture. The planetary gear is installed into the fixture and fixed, and the oil groove is machined out using a cutting tool. This method is more efficient than the first method and is currently the most commonly used method. However, it requires a CNC lathe and matching CNC cutting tools, resulting in higher equipment and tool costs, which cannot meet the current market demand for low-cost solutions.

[0006] Therefore, there is an urgent need to develop a universal, low-cost, and highly efficient method for milling spherical eccentric annular oil grooves in planetary gears. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method and special fixture for milling eccentric annular oil grooves on the spherical surface of planetary gears, which has the advantages of high versatility, low cost, high efficiency and fast changeover.

[0008] To achieve the above objectives, the present invention provides a method for milling eccentric annular oil grooves on a planetary gear spherical surface, comprising the following steps: providing a special fixture, the special fixture comprising a base, a shaft, an adjusting screw, a flange assembly, a gear mold, a pressure plate, a cutter head, a cutter disc, and a cutter shank; rotating the adjusting screw to adjust the included angle between the flange assembly and the base, so that the included angle is consistent with the eccentric included angle of the oil groove on the workpiece; connecting the gear mold to the flange assembly, clamping the workpiece in the gear mold and fixing it with the pressure plate; adjusting the center line of the cutter to be coaxial with the center line of the fixture; controlling the axial feed of the cutter head to a preset depth while rotating the workpiece relative to the cutter head; and releasing the pressure plate after retracting the cutter to remove the workpiece and complete the machining.

[0009] Furthermore, the outer spherical surface of the flange assembly is built into the inner spherical surface of the base to form a spherical mating structure. The shaft passes through the hole in the base and the flange assembly, and the flange assembly rotates around the shaft. The thread on one side of the flange assembly engages with the adjusting screw for transmission. The included angle between the flange assembly and the base can be precisely adjusted by rotating the adjusting screw.

[0010] Furthermore, the flange assembly is also equipped with a hydraulic tightening mechanism, including an oil chamber, oil passage, oil cylinder, spring, piston, and adjusting bolt. By screwing in or out the adjusting bolt, the position of the piston within the oil cylinder can be controlled, thereby increasing or decreasing the volume of the oil chamber through the flow of hydraulic oil, achieving a tight fit or loose separation between the outer spherical surface of the flange assembly and the inner spherical surface of the base. This mechanism ensures sufficient rigid support for the fixture during milling and also enables rapid form changeover.

[0011] Furthermore, the method can be applied to a lathe: the base is fixed to the lathe spindle, the cutter head is fixed to the lathe tool post by the tool holder, the workpiece rotates with the spindle, and the cutter head feeds axially to complete the milling.

[0012] Furthermore, the method can also be applied to a drilling machine: the base is fixed on the drilling machine worktable, the cutter head is fixed on the drilling machine spindle by the cutter bar, and the cutter head rotates with the spindle and feeds axially to complete the milling.

[0013] Furthermore, four oil chambers are provided on the secondary surface of the outer spherical surface of the flange assembly, and the four oil chambers are evenly distributed along the circumference to ensure that the flange assembly and the base are fully fitted and evenly stressed.

[0014] Furthermore, the flange assembly has an angle mark on its outer spherical surface, and a viewing hole is provided at the corresponding position on the base. The scale value of the angle mark can be directly observed through the viewing hole, making it easy to understand the actual eccentric angle being adjusted in a timely manner.

[0015] This invention also provides a dedicated fixture for implementing the above-described method, comprising a base, a shaft, an adjusting screw, a flange assembly, a toothed mold, a pressure plate, a cutter head, a cutter disc, and a cutter bar. The outer spherical surface of the flange assembly is embedded within the inner spherical surface of the base to form a spherical mating deflection mechanism; the adjusting screw drives the flange assembly to rotate around the shaft via thread engagement to adjust the included angle; the flange assembly also integrates a hydraulic tightening mechanism to achieve rigid locking and rapid shape change.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] First, it is highly efficient. The processing efficiency of this invention is more than twice that of the original process, which can significantly increase production capacity.

[0018] Secondly, it has high versatility. This method does not require specialized equipment; it can be used with only machine tools capable of relative rotation and feed motion, such as ordinary lathes, drilling machines, and other general-purpose equipment. Furthermore, the tooling angle is adjustable, making it suitable for various eccentric oil groove products.

[0019] Third, the changeover speed is fast. Utilizing the rapid release / locking function of the hydraulic tensioning mechanism, the changeover time is reduced to half of the original changeover time.

[0020] Fourth, it has low cost. Compared with existing machining centers and CNC lathes, the cost per unit is reduced by more than 40%, resulting in good economic benefits. Attached Figure Description

[0021] Figure 1 This is a cross-sectional and three-dimensional structural schematic diagram of the finished product of the present invention;

[0022] Figure 2 This is a vertical cross-section of the fixture and cutting tool of the present invention, a front view structural schematic diagram;

[0023] Figure 3 These are front and side vertical sectional structural diagrams of the flange assembly of the present invention;

[0024] Figure 4 This is a schematic diagram of the scale value structure on the flange assembly from the perspective of the observation hole of the present invention.

[0025] The attached diagram lists the components represented by each number as follows:

[0026] 1. Base; 101. Centerline (clamp); 102. Observation hole; 2. Shaft; 3. Adjusting screw; 4. Flange assembly; 401. Thread; 402. Hole; 403. Oil chamber; 404. Oil passage; 405. Oil cylinder; 5. Gear mold; 6. Pressure plate; 7. Cutter head; 8. Cutter disc; 9. Tool holder; 10. Workpiece; 11. Spring; 12. Piston; 13. Adjusting bolt; 20. Eccentric annular oil groove; 501. Eccentric angle; 901. Centerline (tool). Detailed Implementation

[0027] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0028] [Overall Structure]

[0029] like Figure 2 As shown, the special fixture used in the milling method for eccentric annular oil grooves on the spherical surface of planetary gears provided by the present invention mainly includes: a base 1, a shaft 2, an adjusting screw 3, a flange assembly 4, a gear mold 5, a pressure plate 6, a cutter head 7, a cutter disc 8, and a cutter bar 9.

[0030] The base 1 is the basic mounting component of the entire fixture and has an inner spherical structure. The base 1 is used to connect and fix to a machine tool (such as a lathe spindle or a drilling machine table). The base 1 is also provided with a viewing hole 102 for observing the angle marks on the flange assembly 4.

[0031] Shaft 2 is the rotation center shaft for angle adjustment. Shaft 2 passes through the hole 402 between the base 1 and the flange assembly 4, which can rotate around shaft 2, thereby changing the angle relative to the base 1.

[0032] The adjusting screw 3 is the driving component for angle adjustment. The adjusting screw 3 is embedded in the base 1 with its axis parallel to the axis of the base 1. The adjusting screw 3 can only rotate relative to its own axis (it cannot move axially). The adjusting screw 3 engages with the thread 401 on one side of the flange assembly 4, forming a worm gear transmission mechanism. When the adjusting screw 3 is rotated, the engagement of the thread 401 drives the flange assembly 4 to rotate around the shaft 2, thereby precisely adjusting the angle between the flange assembly 4 and the base 1. This angle coincides with the eccentric angle 501 of the oil groove in the workpiece 10 to be processed.

[0033] Flange assembly 4 is the core functional component of the entire fixture. The outer spherical surface of flange assembly 4 is embedded within the inner spherical surface of base 1, forming a spherical fit. Flange assembly 4 achieves precise setting of the eccentric angle through the aforementioned spherical fit and screw adjustment mechanism, and integrates a hydraulic tightening mechanism (see below) to achieve rigid locking and quick changeover. The main body of flange assembly 4 is provided with threads 401, holes 402, and the various components of the hydraulic tightening mechanism.

[0034] The gear mold 5 is a workpiece positioning component. The gear mold 5 is connected to the flange assembly 4 by bolts and moves together with the flange assembly 4. The gear mold 5 has a gear mold structure that meshes with the teeth of the workpiece 10 to be processed, ensuring that the workpiece 10 can be accurately and stably positioned within the gear mold 5. When different specifications of planetary gears need to be processed, the corresponding gear mold 5 can be replaced.

[0035] The pressure plate 6 is a workpiece clamping component. After the toothed mold 5 is placed into the toothed portion of the workpiece 10, the pressure plate 6 is used to press the back of the teeth of the workpiece 10, thus firmly fixing the workpiece 10 to the toothed mold 5. The pressure plate 6 can be installed and removed via threaded connection or other quick-release methods.

[0036] The cutter head 7 is the cutting tool used for milling. The cutter head 7 is selected based on the cross-sectional shape and size of the oil groove, and can be a standard tool such as a vertical milling cutter or a disc milling cutter. The cutter head 7 is fixedly mounted on the cutter head 8, which is fixedly connected to the tool holder 9, which is used to connect with the moving parts of the machine tool.

[0037] Hydraulic tensioning mechanism

[0038] like Figure 3 As shown, the hydraulic expansion mechanism integrated on flange assembly 4 is key to achieving rigid support and rapid changeover. This mechanism mainly includes: oil chamber 403, oil passage 404, oil cylinder 405, spring 11, piston 12, and adjusting bolt 13.

[0039] The flange assembly 4 has a sliding fit with the shaft 2, ensuring that the flange assembly 4 can rotate smoothly around the shaft 2. The thread 401 engages with the external thread of the adjusting screw 3 to transmit the adjusting motion.

[0040] The oil chamber 403 is the core working chamber for hydraulic expansion and is located on the secondary surface of the outer spherical surface of the flange assembly 4. The oil chamber 403 is connected to the oil cylinder 405 through the oil passage 404, forming a closed hydraulic circuit. To ensure a full fit between the flange assembly 4 and the base 1 and achieve sufficient rigidity for milling, four oil chambers 403 are provided on the secondary surface of the outer spherical surface of the flange assembly 4, and the four oil chambers 403 are evenly distributed along the circumference.

[0041] The hydraulic cylinder 405 is a hydraulically driven chamber containing a spring 11 and a piston 12. The two ends of the spring 11 rest against the bottom surface of the hydraulic cylinder 405 and the inner end face of the piston 12, respectively, and the spring 11 constantly applies an outward pushing force to the piston 12. The outer end face of the piston 12 contacts the end face of the adjusting bolt 13, which can be rotated to achieve axial movement.

[0042] The working principle of the hydraulic tensioning mechanism is as follows:

[0043] When the clamping fixture needs to be locked (normal machining state): Screw in the adjusting bolt 13, and the piston 12 is pressed into the oil cylinder 405 along with the adjusting bolt 13, compressing the spring 11. After being pressurized, the hydraulic oil in the oil cylinder 405 is forced into the oil chamber 403 through the oil passage 404, which increases the volume of the oil chamber 403 (the hydraulic oil fills the spherical fit gap and expands outward), tightly fitting the outer spherical surface of the flange assembly 4 against the inner spherical surface of the base 1, fixing the flange assembly 4 and the base 1 as one unit, providing sufficient rigidity for milling.

[0044] When the clamp needs to be released (change of configuration): unscrew the adjusting bolt 13. The piston 12 is pushed outward by the restoring force of the spring 11 and the reaction force of the oil pressure in the oil chamber 403. The hydraulic oil in the oil chamber 403 flows back to the oil cylinder 405 through the oil passage 404. The volume of the oil chamber 403 decreases, and the outer spherical surface of the flange assembly 4 contracts inward, loosening its contact with the inner spherical surface of the base 1. At this time, the angle between the flange assembly 4 and the base 1 can be freely adjusted by adjusting the adjusting screw 3.

[0045] [Angle Observation]

[0046] like Figure 4 As shown, to ensure timely understanding of the actual eccentric angle value during adjustment, scale markings (angle markings) are made on the outer spherical surface of flange assembly 4 opposite to the thread 401. Simultaneously, a viewing hole 102 is provided at the corresponding position on base 1. Operators can directly view the scale values ​​on flange assembly 4 through the viewing hole 102, thereby precisely controlling the size of the eccentric angle 501.

[0047] [Working Principle]

[0048] The core principle of this invention lies in establishing an eccentric relationship using a spherical mating deflection mechanism and achieving rigid locking through a hydraulic tightening mechanism. Specifically:

[0049] First, the outer spherical surface of the flange assembly 4 and the inner spherical surface of the base 1 form a spherical fit, allowing the flange assembly 4 to swing at an angle within a certain range relative to the base 1.

[0050] Second, the adjusting screw 3 engages with the flange assembly 4 via threads 401, forming a precision angle adjustment mechanism. Rotating the adjusting screw 3 allows for precise control of the swing angle of the flange assembly 4.

[0051] Third, when the flange assembly 4 is adjusted to the preset angle (equal to the eccentric angle 501 of the workpiece 10), the flange assembly 4 and the base 1 are locked together by the hydraulic tightening mechanism. At this time, there is an eccentricity between the rotation axis formed by the toothed mold 5 on the flange assembly 4 and the workpiece 10 and the tool axis. This eccentricity is determined by the preset angle.

[0052] Fourth, during the machining process, when the workpiece 10 and the cutter head 7 rotate relative to each other, the cutting trajectory of the cutter head 7 on the spherical surface of the workpiece 10 is an eccentric circular trajectory, thereby machining the required eccentric annular oil groove 20.

[0053]

Processing Flow

[0054] The complete processing flow is as follows:

[0055] Step 1: Fixture Assembly and Machine Tool Installation. Fix base 1 to the corresponding position on the selected machine tool (lathe spindle or drilling machine table). Fix the cutter head 8 to another moving part of the machine tool (lathe tool post or drilling machine spindle) via the tool holder 9. Assemble the flange assembly 4, shaft 2, adjusting screw 3, gear mold 5, and other components onto base 1.

[0056] Step 2: Angle Adjustment. Rotate the adjusting screw 3, which drives the flange assembly 4 to rotate around the shaft 2 through the engagement of the screw thread 401. Observe the scale marks in the observation hole 102 until the included angle between the flange assembly 4 and the base 1 reaches the eccentric angle 501 required by the workpiece 10.

[0057] Step 3: Hydraulic locking. Screw in the adjusting bolt 13 to drive the hydraulic expansion mechanism, causing the oil chamber 403 to expand and tightly press the outer spherical surface of the flange assembly 4 against the inner spherical surface of the base 1, thus completing the rigid locking.

[0058] Step 4: Coaxial Adjustment. Adjust the machine tool position or fixture position to ensure that the center line 901 of the tool is coaxial with the center line 101 of the fixture, thus ensuring alignment accuracy.

[0059] Step 5: Workpiece clamping. Place the teeth of the workpiece 10 to be processed into the tooth mold 5, and achieve initial positioning through tooth meshing. Then, use the pressure plate 6 to press the back of the teeth of the workpiece 10, and firmly fix the workpiece 10 to the tooth mold 5.

[0060] Step Six: Milling. Start the machine tool to create a relative rotational motion between the workpiece 10 and the cutter head 7. While rotating, control the cutter head 7 to slowly approach the workpiece 10 along the axial direction to begin milling. Continue feeding until the milling depth reaches the preset oil groove depth.

[0061] Step 7: Unloading. After milling to the desired position, control the cutter head 7 to move axially away from the workpiece 10 and exit the cutting area. After stopping the machine, release the pressure plate 6 to release the clamping of the workpiece 10, and remove the workpiece 10 from the tooth mold 5, thus completing the oil groove machining of one workpiece.

[0062] Example 1: Lathe Machining Mode

[0063] The specific implementation method of applying the present invention to a lathe is as follows:

[0064] First, fix the base 1 to the lathe spindle (usually connected via a flange or three-jaw chuck), and fix the cutter head 8 to the lathe tool post via the tool holder 9. Assemble the flange assembly 4, shaft 2, adjusting screw 3, gear mold 5, and other components. Adjust the position of the lathe tailstock or tool post to align the spindle rotation centerline (i.e., the fixture centerline 101) with the cutter head centerline (i.e., the tool centerline 901) to a coaxial state.

[0065] Rotate the adjusting screw 3 to adjust the included angle between the flange assembly 4 and the base 1 to the required eccentric angle 501 of the workpiece 10. Confirm the angle value by observing the scale marks on the side of the flange assembly 4 through the observation hole 102 on the base 1.

[0066] Tighten the adjusting bolt 13 to activate the hydraulic tightening mechanism, so that the flange assembly 4 and the base 1 are rigidly locked together.

[0067] After starting the lathe, the spindle drives the base 1, flange assembly 4, gear mold 5, and workpiece 10 to rotate together. The rotation speed can be selected from 50 to 200 revolutions per minute depending on the workpiece material and size. At the same time, rotate the tool post handle or activate automatic feed to bring the tool head 7, tool disc 8, tool holder 9, and tool post together axially (in the Z-axis direction of the lathe) closer to the workpiece 10. After the tool head 7 contacts the spherical surface of the workpiece 10, milling cutting begins, and the feed continues until the preset oil groove depth is reached (generally determined according to the product design drawings, with a typical value of 0.5 to 2 mm).

[0068] After milling to the desired position, reverse the handle or activate the automatic tool retraction to move the cutter head 7 away from the workpiece 10 along the axial direction. After stopping the machine, release the pressure plate 6, remove the workpiece 10, and the machining is complete.

[0069] In this mode, since the mature spindle rotation function and tool post feed function of the lathe are utilized, there is no need to equip an additional CNC system or special device, and the equipment investment cost is extremely low.

[0070] [Example 2: Drilling Machine Machining Mode]

[0071] The specific implementation method of applying the present invention to a drilling machine is as follows:

[0072] First, fix the base 1 to the worktable of the drilling machine (using a pressure plate or special fixture). Fix the cutter head 8 to the spindle of the drilling machine via the cutter shank 9 (usually connected via a drill chuck or Morse taper shank). Assemble the flange assembly 4 and other components. Adjust the position of the worktable or spindle so that the center line of the drilling machine spindle (i.e., the center line 901 of the cutter) and the center line of the gear mold 5 (i.e., a part of the center line 101 of the fixture) are aligned on the same axis.

[0073] Similarly, rotate the adjusting screw 3 to adjust the included angle to the eccentric included angle 501, and screw in the adjusting bolt 13 to complete the hydraulic locking.

[0074] After starting the drilling machine, the spindle drives the cutter head 7, cutter head 8, and cutter shank 9 to rotate together. The rotation speed can be selected within the range of 100 to 500 revolutions per minute according to the machining requirements. At the same time, operate the drilling machine feed handle (or activate automatic feed) to make the rotating cutter head 7 approach the workpiece 10 along the axial direction (vertically downward). After the cutter head 7 contacts the spherical surface of the workpiece 10, milling cutting begins, and the feed continues until the preset oil groove depth is reached.

[0075] After milling to the desired position, operate the retracting handle to move the cutter head 7 axially upward away from the workpiece 10. After stopping the machine, release the pressure plate 6, remove the workpiece 10, and the machining is complete.

[0076] In this mode, the high rotational accuracy and good axial rigidity of the drilling machine spindle are utilized, making it suitable for applications requiring high machining accuracy.

[0077] [Change of type operation]

[0078] When it is necessary to process planetary gears of different specifications (i.e., oil grooves with different eccentric angles), a hydraulic tightening mechanism can be used to achieve quick changeover. The specific steps are as follows:

[0079] Step 1: Unscrew the adjusting bolt 13. Under the reaction force of the spring 11 and the oil pressure, the piston 12 is pushed outward. The hydraulic oil in the oil chamber 403 flows back to the oil cylinder 405 through the oil passage 404. The outer spherical surface of the flange assembly 4 retracts inward, loosening its contact with the inner spherical surface of the base 1.

[0080] Step 2: Adjust the angle between the flange assembly 4 and the base 1 by adjusting screw 3 until it matches the eccentric angle of the replacement product. During this process, the hydraulic tensioning mechanism has been released, allowing the flange assembly 4 to rotate freely.

[0081] Step 3: Screw in the adjusting bolt 13. The piston 12 is pressed into the oil cylinder 405 along with the adjusting bolt 13. The hydraulic oil in the oil cylinder 405 is pressed into the oil chamber 403 through the oil passage 404, which increases the volume of the oil chamber 403. This tightly fits the outer spherical surface of the flange assembly 4 into the inner spherical surface of the base 1, and the flange assembly 4 and the base 1 are fixed together again.

[0082] Step 4: Replace the tooth mold 5 with a model that matches the specifications of the new workpiece, and at the same time replace the corresponding disc milling cutter (if necessary), thus completing the tooling change of the product.

[0083] The entire changeover process only requires half the original changeover time, significantly improving the efficiency of multi-variety, small-batch production.

[0084] [Verification of Beneficial Effects]

[0085] Through actual production verification, this invention has the following significant advantages over existing technologies:

[0086] In terms of processing efficiency, the single-piece processing cycle of this invention is less than half that of the original CNC lathe process, increasing efficiency by more than double. This is mainly because it eliminates CNC programming and tool setting time, simplifies clamping, and significantly reduces auxiliary time.

[0087] In terms of equipment versatility, this method does not require specialized equipment; only machine tools with relative rotation and feed motion are needed. Common general-purpose equipment such as ordinary lathes, drilling machines, horizontal boring machines, and even radial drilling machines can be used, allowing companies to choose flexibly according to their own equipment conditions. Furthermore, the tooling angle is adjustable, and one set of fixtures can be used to process different eccentric oil groove products, further improving equipment utilization.

[0088] In terms of changeover efficiency, the quick-release / locking function of the hydraulic tensioning mechanism reduces changeover time to half of the original time. This advantage is particularly evident in multi-variety, small-batch production models.

[0089] In terms of cost, since ordinary equipment can be used instead of expensive machining centers or CNC lathes, and standard milling cutters are used instead of special CNC cutting tools, the cost per unit is reduced by more than 40%, resulting in significant economic benefits.

[0090] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A method for milling eccentric annular oil grooves on the spherical surface of a planetary gear, characterized in that, Includes the following steps: S1: A special fixture is provided, the special fixture including a base (1), a shaft (2), an adjusting screw (3), a flange assembly (4), a toothed mold (5), a pressure plate (6), a cutter head (7), a cutter disc (8), and a cutter bar (9), wherein the outer spherical surface of the flange assembly (4) is built into the inner spherical surface of the base (1), the shaft (2) passes through the hole of the base (1) and the flange assembly (4), the flange assembly (4) rotates around the shaft (2), the thread on one side of the flange assembly (4) meshes with the adjusting screw (3), the adjusting screw (3) is embedded in the base (1) and its axis is parallel to the axis of the base (1); S2: Rotate the adjusting screw (3) to adjust the included angle between the flange assembly (4) and the base (1) so that the included angle is consistent with the eccentric included angle (501) of the oil groove of the workpiece (10). The adjusting screw (3) and the flange assembly (4) are connected by thread engagement and self-locking by thread engagement. S3: Connect the tooth mold (5) to the flange assembly (4) with bolts, place the tooth of the workpiece (10) inside the tooth mold (5), and use the pressure plate (6) to press the back of the tooth of the workpiece (10) to fix the workpiece (10) and the tooth mold (5). S4: Fix the cutting head (7) on the cutting disc (8), fix the cutting disc (8) and the cutting bar (9), and adjust so that the center line (901) of the cutting tool is coaxial with the center line (101) of the fixture; S5: While rotating the workpiece (10) relative to the cutter head (7), control the cutter head (7) to move closer to the workpiece (10) until milling reaches the oil groove depth, and then move the cutter head (7) away from the workpiece (10). S6: Release the pressure plate (6), remove the workpiece (10), and complete the processing of a workpiece oil groove.

2. The method for milling eccentric annular oil grooves on a planetary gear according to claim 1, characterized in that, In step S2, the angle is adjusted by the cooperation between the outer spherical surface of the flange assembly (4) and the inner spherical surface of the base (1). The adjusting screw (3) can only rotate relative to its own axis to drive the flange assembly (4) to rotate around the shaft (2).

3. The method for milling eccentric annular oil grooves on a planetary gear according to claim 1, characterized in that, The flange assembly (4) is provided with a hydraulic tightening mechanism, which includes an oil chamber (403), an oil passage (404), an oil cylinder (405), a spring (11), a piston (12), and an adjusting bolt (13). The oil chamber (403) is connected to the oil cylinder (405) through the oil passage (404). The oil cylinder (405) contains the spring (11) and the piston (12). The two ends of the spring (11) rest against the bottom surface of the oil cylinder (405) and the inner end face of the piston (12), respectively. The outer end face of the piston (12) contacts the end face of the adjusting bolt (13).

4. The method for milling eccentric annular oil grooves on a planetary gear according to claim 3, characterized in that, The hydraulic tightening mechanism works as follows: when the adjusting bolt (13) is screwed in, the piston (12) is pressed into the oil cylinder (405) along with the adjusting bolt (13). The hydraulic oil in the oil cylinder (405) is pressed into the oil chamber (403) through the oil passage (404), which increases the volume of the oil chamber (403) and tightly fits the outer spherical surface of the flange assembly (4) against the inner spherical surface of the base (1), so that the flange assembly (4) and the base (1) are fixed and stable.

5. The method for milling an eccentric annular oil groove on a planetary gear according to claim 3, characterized in that, When changing models, the operation mode of the hydraulic expansion mechanism is as follows: unscrew the adjusting bolt (13), the piston (12) is pushed outward under the reaction force of the spring (11) and the oil pressure, the hydraulic oil in the oil chamber (403) flows back to the oil cylinder (405) through the oil passage (404), the outer spherical surface of the flange assembly (4) contracts inward, loosens the fit with the inner spherical surface of the base (1), and adjusts the angle between the flange assembly (4) and the base (1) by the adjusting screw (3) until the eccentric angle of the changing product is consistent, and then screws in the adjusting bolt (13) to lock it again.

6. The method for milling a spherical eccentric annular oil groove on a planetary gear according to claim 1, characterized in that, The method is applied to a lathe, specifically as follows: the base (1) is fixed on the spindle of the lathe, the cutter head (8) is fixed on the tool post of the lathe through the tool bar (9), and the center line of the spindle and the cutter head is adjusted to be coaxial; after the lathe is started, the workpiece (10) and the gear mold (5) rotate with the spindle, and the cutter head (7), the cutter head (8), the tool bar (9) and the tool post move axially toward the workpiece (10) until the milling reaches the oil groove depth, and the cutter head (7) moves away from the workpiece (10).

7. The method for milling a spherical eccentric annular oil groove on a planetary gear according to claim 1, characterized in that, The method is applied to a drilling machine, specifically: the base (1) is fixed on the worktable of the drilling machine, the cutter head (8) is fixed on the spindle of the drilling machine through the cutter bar (9), and the center line of the spindle of the drilling machine and the center line of the gear mold (5) are adjusted to the same axis; after the drilling machine is started, the cutter head (7), cutter head (8), and cutter bar (9) rotate with the spindle and move axially closer to the workpiece (10) until the milling reaches the oil groove depth, and the cutter head (7) moves away from the workpiece (10).

8. The method for milling a spherical eccentric annular oil groove on a planetary gear according to claim 1, characterized in that, The flange assembly (4) has four oil chambers (403) on its outer spherical subsurface, and the four oil chambers (403) are evenly distributed along the circumferential direction.

9. A special fixture for implementing the method according to any one of claims 1-8, characterized in that, include: The base (1) has an inner spherical structure; Shaft (2), the shaft (2) passes through the hole (402) of the base (1) and flange assembly (4); Adjusting screw (3), the adjusting screw (3) is embedded in the base (1) and its axis is parallel to the axis of the base (1); Flange assembly (4), the outer spherical surface of the flange assembly (4) is built into the inner spherical surface of the base (1), the flange assembly (4) rotates around the shaft (2), and one side of the flange assembly (4) has threads (401) that mesh with the adjusting screw (3); The tooth mold (5) is connected to the flange assembly (4) by bolts; Pressure plate (6), the pressure plate (6) is used to press the back of the teeth of the workpiece (10); A cutting head (7) is used to perform milling on the workpiece (10); The cutter head (7) is fixedly mounted on the cutter head (8); The cutter bar (9) is fixedly connected to the cutter disc (8).

10. The special fixture according to claim 9, characterized in that, The flange assembly (4) further includes a hydraulic tightening mechanism, which includes an oil chamber (403), an oil passage (404), an oil cylinder (405), a spring (11), a piston (12), and an adjusting bolt (13). The oil chamber (403) is connected to the oil cylinder (405) through the oil passage (404). The oil cylinder (405) contains the spring (11) and the piston (12). The two ends of the spring (11) rest against the bottom surface of the oil cylinder (405) and the inner end face of the piston (12), respectively. The outer end face of the piston (12) contacts the end face of the adjusting bolt (13). An angle mark is provided on the outer spherical surface of the flange assembly (4) opposite to the thread, and an observation hole (102) is provided at the corresponding position of the base (1). The scale value of the angle mark can be directly observed through the observation hole (102).

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