Press fitting tool and method for bearing assembly of main speed reducer of automobile drive axle

Abstract

The invention provides a press fitting tool and method for a bearing assembly of an automobile drive axle main speed reducer, relates to the technical field of bearing press fitting, and is mainly used for press fitting of the bearing assembly of the automobile drive axle main speed reducer. The bearing assembly press-fitting tool comprises a first workbench, a first press-fitting device, a first press-fitting tool body and a second press-fitting tool body, wherein the first workbench is provided with a positioning base used for fixing a speed reducer shell, the first press-fitting device is located above the positioning base, the first press-fitting tool body is used for press-fitting a bearing inner ring on an intermediate shaft, and the second press-fitting tool body is used for press-fitting a bearing outer ring on the outer side of the bearing inner ring. The bearing assembly press-fitting method comprises the steps that a to-be-press-fitted workpiece is placed on the positioning base, and the first press-fitting tool and the second press-fitting tool are used for press-fitting of a second bearing inner ring, press-fitting of a second bearing outer ring, press-fitting of a first bearing inner ring and press-fitting of a first bearing outer ring correspondingly; by means of the bearing assembly press-fitting tool and method, the coaxiality precision and the assembling stability in the speed reducer bearing assembling process can be further improved through the arranged special tool.

Description

Technical Field

[0001] This invention belongs to the field of bearing press-fitting technology, and specifically relates to a bearing assembly press-fitting fixture and method for an automotive drive axle main reducer. Background Technology

[0002] The main reducer of the drive axle is a mechanism within the drive axle that can change torque and speed. Existing electric drive axle main reducers typically employ a two-stage spur gear or a two-stage helical gear reduction structure. However, spur gears have limited load-bearing capacity, and helical gear transmissions have an axial force component, thus often presenting the following problems:

[0003] (1) The load-bearing capacity of straight teeth on the same size platform is weaker than that of helical teeth, and the space for increasing power density is limited;

[0004] (2) When assembling a single pair of spur gears, the centering problem needs to be considered, and the load may be uneven. When assembling a single pair of helical gears, there is a problem of unilateral axial force. When assembling multiple pairs of gears, the gear helix arrangement needs to be considered to balance the axial force.

[0005] (3) The overlap ratio of spur gears is relatively small. The overlap ratio of helical gears on the same platform is slightly larger than that of spur gears. However, gear knocking is likely to occur during spur or helical gear transmission, which will cause vibration and noise in the system.

[0006] To address the aforementioned issues, Chinese patent application CN111828583A discloses an "Automotive Drive Axle Main Reducer," specifically comprising a reducer housing 1, an input shaft and an intermediate shaft rotatably mounted within the reducer housing 1, and a differential assembly rotatably mounted on the reducer housing 1. The intermediate shaft has a first-stage driven gear and a second-stage driving gear; the input shaft has a first-stage driving gear meshing with the first-stage driven gear; and the differential assembly has a second-stage driven gear meshing with the second-stage driving gear. All three gears—first-stage driving gear, first-stage driven gear, second-stage driving gear, and second-stage driven gear—are circular arc toothed cylindrical gears. This use of circular arc toothed cylindrical gears for transmission enhances the load-bearing capacity of the main reducer on the same platform and eliminates axial force. Furthermore, it allows for automatic alignment during installation and gear meshing, eliminating axial movement of the gears.

[0007] To address the problems of low strength, complex manufacturing process, high cost, and high after-sales failure rate at the parting surface in existing split-design, assembled reducer housings, the aforementioned automotive drive axle main reducer is designed as follows: Figure 1 The integrally formed irregular frame structure shown improves the overall strength of the reducer housing 1.

[0008] However, after designing the reducer housing 1 as a one-piece structure, the first-stage driven gear cannot be directly installed through the opening in the side wall of the reducer housing 1. Instead, it is placed into the designated position in the reducer housing 1 through the connection hole between the gear and the reducer cavity. Then, the intermediate shaft and the second-stage driving gear are placed inside the reducer housing 1, and the first bearing 11 and the second bearing 12 at both ends of the intermediate shaft are installed. Specifically, when installing the intermediate shaft in the aforementioned one-piece reducer housing 1, due to the irregular dimensions of the reducer housing 1, the first-stage driven gear must first be installed in the connection hole inside the reducer housing 1, and then the intermediate shaft and the second-stage driving gear are placed together. The reducer housing 1 is interference-fitted with the first-stage driven gear. Then, the first bearing 11 and the second bearing 12 at both ends of the intermediate shaft are press-fitted between the intermediate shaft and the reducer housing 1. Both the first bearing 11 and the second bearing 12 are tapered roller bearings. High installation accuracy is required for the inner and outer rings of the bearings during the press-fitting process. However, in traditional manual bearing assembly, especially for the assembly of the first bearing 11 and the second bearing 12 at both ends of the intermediate shaft with the first-stage driven gear located within the reducer housing 1, manual press-fitting makes it difficult to ensure the concentricity of the bearings and gear shafts, easily leading to bearing misalignment, uneven clearance, and affecting transmission accuracy and bearing life. Therefore, it is necessary to set up a corresponding bearing assembly press-fitting fixture and method. Summary of the Invention

[0009] This invention provides a tooling and method for pressing bearing assemblies of automotive drive axle main reducers. It is mainly used for pressing bearing assemblies of automotive drive axle main reducers. By setting up a dedicated tooling, the coaxiality accuracy and assembly stability of the reducer bearings during the assembly process are further improved.

[0010] The present invention discloses a bearing assembly press-fitting fixture for a main reducer of an automotive drive axle, comprising a first worktable, a positioning base for fixing the reducer housing on the first worktable, and a first press-fitting device located above the positioning base on the first worktable.

[0011] It also includes a first press-fitting fixture for press-fitting the inner ring of the bearing onto the intermediate shaft and a second press-fitting fixture for press-fitting the outer ring of the bearing onto the outer side of the inner ring of the bearing.

[0012] The first pressing fixture includes a first positioning shaft that abuts against and is coaxially arranged with the intermediate shaft. The lower end of the first positioning shaft is provided with a first centering shaft that is adapted to the intermediate hole of the intermediate shaft. The lower end of the first centering shaft is provided with a top tip with a gradually decreasing cross-sectional diameter. An inner ring pressing sleeve with a first cavity inside is slidably connected to the outer side of the first positioning shaft. A first support housing that is connected to the reducer housing is slidably connected to the outer side of the inner ring pressing sleeve. The top of the inner ring pressing sleeve is provided with a first pressing table that is connected to the first pressing equipment. A limiting post located in the first cavity is fixed to the lower surface of the first pressing table. The lower end of the inner ring pressing sleeve is provided with an inner ring pressing head that abuts against the inner ring of the bearing. There is a first space between the outer side of the inner ring pressing head and the inner side of the first support housing for the inner ring of the bearing to pass through. A slider that is slidably connected to the inner side of the first support housing is provided above the inner ring pressing head.

[0013] The second press-fitting fixture includes a second positioning shaft coaxially arranged with the inner ring of the bearing. The top of the second positioning shaft is provided with a second press-fitting table connected to the first press-fitting equipment. An outer ring press sleeve is fixedly provided at the lower end of the second positioning shaft. The inner side of the outer ring press sleeve is provided with a second space for the inner ring of the bearing to pass through. The inner side of the outer ring press sleeve is also provided with a third space connected to the second space and for the intermediate shaft to pass through. The lower end of the outer ring press sleeve is provided with an outer ring press head connected to the outer ring of the bearing. A second support housing connected to the reducer housing is slidably connected to the outer side of the outer ring press sleeve. The diameter of the second support housing is adapted to the diameter of the outer ring of the bearing to place the outer ring of the bearing inside the second support housing and connect it with the outer ring press head.

[0014] Furthermore, a spring is sleeved on the outer side of the limiting post, with one end of the spring abutting against the lower bottom surface of the first pressing table and the other end abutting against the upper top surface of the first positioning shaft.

[0015] Furthermore, a first limiting boss is horizontally provided above the first support housing. The first limiting boss extends toward the first press-fit workpiece, and the bottom surface of the first limiting boss abuts against the top surface of the vertical guide mechanism.

[0016] The top of the first positioning shaft is provided with a second limiting boss, which extends toward the inner ring pressure head and the bottom surface of the second limiting boss abuts against the top surface of the inner ring pressure head.

[0017] Furthermore, a limiting platform is provided above the second support housing, which is coaxially arranged with the second positioning shaft. The second positioning shaft is slidably disposed within the limiting platform. The diameter of the limiting platform is smaller than the diameter of the second support housing. The upper top surface of the limiting platform abuts against the lower bottom surface of the second pressing platform.

[0018] Furthermore, the lower end of the first positioning shaft is provided with a first stop that is adapted to the intermediate shaft, and the lower end of the outer ring pressure head is provided with a top spring that is adapted to the outer ring of the bearing.

[0019] Furthermore, it also includes a limiting plate; the limiting plate has a through groove for the intermediate shaft to pass through, and the circumference of the through groove is also provided with a groove for placing the first-stage driven gear, and the limiting plate is also provided with a hand-held part.

[0020] As a preferred embodiment, the handheld part is a through hole formed on the limiting plate.

[0021] Furthermore, the lower end of the positioning base is fixed to the first workbench, and the top of the positioning base is provided with a first limiting ring and a second limiting ring. The first limiting ring has a second cavity for the intermediate shaft to pass through. The second limiting ring is arranged around the outside of the first limiting ring and is coaxial with the first limiting ring. There is a gap between the second limiting ring and the first limiting ring for positioning the reducer housing, and the height of the second limiting ring is lower than that of the first limiting ring.

[0022] Furthermore, it also includes a second worktable for pre-pressing the second bearing onto the intermediate shaft, the second worktable being provided with a fixed base, and the second worktable also being provided with a second pressing device located above the fixed base; a third pressing fixture for pressing the second bearing onto the intermediate shaft is fixedly connected below the second pressing device.

[0023] A positioning sleeve is detachably installed on the fixed base. The fixed base is provided with a positioning boss, and a positioning groove for fixing the intermediate shaft is opened in the center of the positioning boss. The bottom of the positioning sleeve is provided with an insertion cavity that matches the positioning boss. Above the insertion cavity is a limiting cavity located inside the positioning sleeve for placing and fixing the second bearing on the intermediate shaft. The inner diameter of the limiting cavity is larger than the diameter of the stage II drive gear.

[0024] The third pressing fixture includes a mounting base fixedly connected to the bottom surface of the second pressing equipment. A pressing rod extending downward is fixedly provided below the mounting base. The bottom end of the pressing rod is provided with a pressing surface for pressing the second bearing. The bottom end of the pressing rod is provided with a second centering shaft extending downward and connected to the centering of the intermediate shaft. The end of the second centering shaft facing the intermediate shaft is provided with a tip with a gradually decreasing cross-sectional diameter. The diameter of the second centering shaft is smaller than the diameter of the pressing rod.

[0025] As a preferred embodiment, the side of the positioning sleeve has at least two slots that communicate with the limiting cavity.

[0026] This invention also discloses a method for press-fitting a bearing assembly of an automotive drive axle final reducer, comprising using the aforementioned press-fitting fixture for the bearing assembly of an automotive drive axle final reducer, and including the following steps:

[0027] Step 1: Place the reducer housing on the positioning base, and place the stage I driven gear, stage II driving gear, and intermediate shaft into the reducer housing;

[0028] The reducer housing is positioned on the positioning base. The reducer housing has a positioning pin that matches the positioning base on the outer side of the end near the first stage driven gear. The first stage driven gear is placed inside the reducer housing. Then, the intermediate shaft with the second stage driving gear is placed inside the reducer housing. The other end of the intermediate shaft passes through the first stage driven gear and abuts against the positioning base.

[0029] Step 2: Press-fit the inner ring of the second bearing;

[0030] The second bearing inner ring is placed on the intermediate shaft and aligned. Then, the first pressing fixture is placed on the reducer housing. The first positioning shaft of the first pressing fixture is centered and connected to the intermediate shaft. The first pressing device presses down on the first pressing fixture, driving the inner ring pressing head of the first pressing fixture to press down on the second bearing inner ring, pressing the second bearing inner ring onto the intermediate shaft. The tip of the first centering shaft presses down synchronously with the first positioning shaft. Under the action of gravity, the tip guides the intermediate shaft and presses it onto the stage I driven gear. After the second bearing inner ring is pressed down, the first pressing fixture is removed.

[0031] Step 3: Press-fit the outer ring of the second bearing;

[0032] The outer ring of the second bearing is placed inside the second support housing of the second press-fitting fixture and connected to the outer ring press head of the second press-fitting fixture. The second press-fitting fixture is then placed on the reducer housing and positioned above the already press-fitted inner ring of the second bearing and coaxial with the intermediate shaft. The first press-fitting device presses down on the second press-fitting fixture, driving the outer ring press head of the second press-fitting fixture to press down on the outer ring of the second bearing, thus pressing the outer ring of the second bearing onto the inner ring of the second bearing. After the outer ring of the second bearing is press-fitted, the second press-fitting fixture is removed.

[0033] Step 4: Flip the reducer housing;

[0034] After pressing in the inner ring and outer ring of the second bearing, flip the reducer housing so that the side of the reducer housing closest to the first stage driven gear faces the first pressing device.

[0035] Step 5: Press-fit the inner ring of the first bearing;

[0036] The inner ring of the first bearing is placed on the intermediate shaft and aligned. Then, the first pressing fixture is placed on the reducer housing. The first positioning shaft of the first pressing fixture is centered and connected to the intermediate shaft. The first pressing equipment presses down on the first pressing fixture, driving the inner ring pressing head of the first pressing fixture to press down on the inner ring of the first bearing and press it onto the intermediate shaft. At the same time, the limiting post under the first pressing table of the first pressing fixture presses down and abuts against the first positioning shaft. After the inner ring of the first bearing is pressed down, the first pressing fixture is removed.

[0037] Step Six: Press-fit the outer ring of the first bearing;

[0038] The outer ring of the first bearing is placed inside the second support housing of the second press-fitting fixture and connected to the outer ring press head of the second press-fitting fixture. The second press-fitting fixture is then placed on the reducer housing and positioned above the already press-fitted inner ring of the first bearing and coaxial with the intermediate shaft. The first press-fitting device presses down on the second press-fitting fixture, driving the outer ring press head of the second press-fitting fixture to press down on the outer ring of the first bearing, thus pressing the outer ring of the first bearing onto the inner ring of the first bearing. After the outer ring of the first bearing is press-fitted, the first press-fitting fixture is removed.

[0039] Complete the press-fitting of the bearing assembly of the main reducer of the automotive drive axle.

[0040] Furthermore, the bearing assembly press-fitting fixture of the automotive drive axle main reducer also includes a second worktable, on which a fixed base is provided, and a second press-fitting device located above the fixed base is also provided on the second worktable; a third press-fitting fixture for press-fitting the second bearing onto the intermediate shaft is fixedly connected below the second press-fitting device.

[0041] Before step one, the second bearing is pre-pressed. The intermediate shaft, which is integrally set with the stage II drive gear, is placed in the positioning sleeve of the fixed base on the second workbench. The lower end of the intermediate shaft is inserted into the positioning groove. The second pressing device presses down, driving the pressing rod of the third pressing tool to press down. The centering shaft of the pressing rod is connected to the centering of the intermediate shaft. The pressing surface of the pressing rod presses the second bearing onto the intermediate shaft.

[0042] Furthermore, the bearing assembly press-fitting fixture of the automotive drive axle main reducer also includes a limiting plate; the limiting plate has a through groove for the intermediate shaft to pass through, and the through groove is also provided with a groove for the stage driven gear to be placed in the circumferential direction; the limiting plate is also provided with a hand-held part; before step two, the limiting plate is placed; the through groove of the limiting plate passes through the intermediate shaft set in the reducer housing, and the limiting plate is placed between the stage I driven gear and the reducer housing.

[0043] The beneficial effects of the present invention are as follows: The present invention provides a bearing assembly press-fitting fixture for an automotive drive axle main reducer. By setting corresponding first press-fitting fixtures for pressing the inner ring of the bearing and second press-fitting fixtures for pressing the outer ring of the bearing, the coaxiality accuracy and assembly stability of the reducer bearing during the assembly process are further improved, ensuring the transmission accuracy and bearing life during use.

[0044] The present invention provides a method for press-fitting bearing assemblies of automotive drive axle main reducers. Based on the above-mentioned bearing assembly press-fitting fixture, it enables fast and accurate press-fitting of reducer bearings, improves the coaxiality accuracy and assembly stability of the reducer bearings during the assembly process, and ensures transmission accuracy and bearing life during use. Attached Figure Description

[0045] Figure 1 This is a cross-sectional schematic diagram of the speed reducer according to an embodiment of the present invention;

[0046] Figure 2 A cross-sectional view of the first pressing fixture provided in an embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the bearing inner ring press-fitting process provided in an embodiment of the present invention;

[0048] Figure 4 A cross-sectional view of the second pressing fixture provided in an embodiment of the present invention;

[0049] Figure 5 This is a schematic diagram of the bearing outer ring press-fitting process provided in an embodiment of the present invention;

[0050] Figure 6 This is a schematic diagram of the second workbench and the third pressing tool used in the pressing process according to an embodiment of the present invention.

[0051] Figure 7 A schematic diagram of the positioning sleeve provided in an embodiment of the present invention;

[0052] Figure 8 This is a schematic diagram of the placement of the limiting disk provided in an embodiment of the present invention;

[0053] Figure 9 This is a schematic diagram of the limiting disk structure provided in an embodiment of the present invention;

[0054] Reference numerals: 1-Reducer housing; 11-First bearing; 111-Inner ring of first bearing; 112-Outer ring of first bearing; 12-Second bearing; 121-Inner ring of second bearing; 122-Outer ring of second bearing; 13-Intermediate shaft; 131-Stage I driven gear; 132-Stage II driving gear; 2-First worktable; 21-Positioning base; 211-First limiting ring; 212-Second limiting ring; 213-Second cavity; 22-First press fitting Equipment; 3-First pressing fixture; 31-First positioning shaft; 311-Second limiting boss; 312-First stop; 313-First centering shaft; 32-Inner ring pressure sleeve; 321-First cavity; 322-First pressing table; 323-Limiting post; 324-Spring; 33-Inner ring pressure head; 331-First space; 34-Slider; 35-First support housing; 351-First limiting boss; 4-Second pressing fixture; 41-Second positioning shaft; 42-Second pressing table; 43-Outer ring pressing sleeve; 431-Second space; 432-Third space; 44-Outer ring pressing head; 441-Top spring; 45-Second support housing; 451-Limiting platform; 5-Limiting plate; 51-Through groove; 52-Groove; 53-Handheld part; 531-Through hole; 6-Second worktable; 61-Fixed base; 611-Positioning block; 612-Positioning boss; 6121-Contact surface; 613-Positioning groove; 614-Bearing ring plate; 615-Handheld section; 62-Positioning sleeve; 621-Insertion cavity; 622-Limiting cavity; 624-Groove; 625-Positioning groove; 626-Notch; 63-Second pressing equipment; 7-Third pressing fixture; 71-Mounting seat; 72-Pressing rod; 721-Pressing surface; 73-Second centering shaft. Detailed Implementation

[0055] The present invention will be further described below.

[0056] like Figures 1-9As shown, this invention provides a bearing assembly press-fitting fixture for a vehicle drive axle main reducer, mainly used for press-fitting bearing assemblies of a vehicle drive axle main reducer. It includes a first worktable 2, on which a positioning base 21 for fixing the reducer housing 1 is provided. The first worktable 2 also includes a first press-fitting device 22 located above the positioning base 21. It further includes a first press-fitting fixture 3 for press-fitting the inner ring of the bearing onto an intermediate shaft 13 and a second press-fitting fixture 4 for press-fitting the outer ring of the bearing onto the outer side of the inner ring. The first press-fitting fixture 3 includes a first positioning shaft 31 that abuts against and is coaxially arranged with the intermediate shaft 13. A first centering shaft 313 is provided at the lower end of a positioning shaft 31 to fit the intermediate hole of the intermediate shaft 13. The lower end of the first centering shaft 313 is provided with a top tip with a gradually decreasing cross-sectional diameter. An inner ring sleeve 32 with a first cavity 321 is slidably connected to the outer side of the first positioning shaft 31. A first support housing 35 connected to the reducer housing 1 is slidably connected to the outer side of the inner ring sleeve 32. A first pressing platform 322 connected to the first pressing device 22 is provided at the top of the inner ring sleeve 32. A limiting post 323 located in the first cavity 321 is fixedly connected to the lower surface of the first pressing platform 322. The limiting post 323 is located below... The distance between the end of the inner ring and the bottom of the first positioning shaft 31 is greater than the pressing stroke of the inner ring press head 33 pressing the inner ring 111 of the first bearing; the lower end of the inner ring press sleeve 32 is provided with an inner ring press head 33 that abuts against the inner ring of the bearing, and there is a first space 331 between the outer side of the inner ring press head 33 and the inner side of the first support housing 35 for the inner ring of the bearing to pass through; a slider 34 that is slidably connected to the inner side of the first support housing 35 is provided above the inner ring press head 33; the second pressing fixture 4 includes a second positioning shaft 41 coaxially arranged with the inner ring of the bearing, and the top of the second positioning shaft 41 is provided with a second pressing table 42 that is connected to the first pressing device 22. The lower end of the second positioning shaft 41 is fixedly provided with an outer ring pressure sleeve 43. The inner side of the outer ring pressure sleeve 43 is provided with a second space 431 for the inner ring of the bearing to pass through. The second positioning shaft 41 is provided with a third space 432 that communicates with the second space 431 and is used for the intermediate shaft 13 to pass through. The lower end of the outer ring pressure sleeve 43 is provided with an outer ring pressure head 44 that abuts against the outer ring of the bearing. The outer side of the outer ring pressure sleeve 43 is slidably connected with a second support housing 45 that is connected to the reducer housing 1. The diameter of the second support housing 45 is adapted to the diameter of the outer ring of the bearing to place the outer ring of the bearing inside the second support housing 45 and connect with the outer ring pressure head 44.

[0057] like Figure 2 , Figure 3As shown, the bearing assembly press-fitting fixture for the main reducer of the automotive drive axle includes a first worktable 2, on which the first bearing 11 and the second bearing 12 are press-fitted. Specifically, the reducer housing 1 is placed on the positioning base 21, and the first-stage driven gear 131 is placed inside the reducer housing 1. The intermediate shaft 13 with the second-stage driving gear 132 is placed inside the reducer housing 1, and the other end of the intermediate shaft 13 passes through the first-stage driven gear 131 and abuts against the positioning base 21. The first press-fitting device 22, located above the positioning base 21, presses down the first press-fitting fixture 3 to press the inner rings of the first bearing 11 and the second bearing 12 onto the intermediate shaft 13. The first press-fitting device 22 then presses down the second press-fitting fixture 4 to press the outer rings of the first bearing 11 and the second bearing 12 onto the corresponding inner rings. During the pressing process, the tip of the first centering shaft 313 first enters the middle hole of the intermediate shaft 13 to guide and position the first positioning shaft 31, so that the first positioning shaft 31 of the first pressing fixture 3 abuts against the intermediate shaft 13, thereby ensuring the concentricity of the bearing and the intermediate shaft 13 when the inner ring pressing sleeve 32 is pressing the bearing inner ring. The outer side of the first positioning shaft 31 is slidably connected to the inner ring pressing sleeve 32, which has a first cavity 321 inside. The lower end of the inner ring pressing sleeve 32 is provided with an inner ring pressing head 33 for pressing the bearing inner ring. The first cavity 321 provided in the inner ring pressing sleeve 32 is located above the first positioning shaft 31, so as to set a limiting post 323, so as to effectively avoid the problem that the first positioning shaft 31 completely slides into the inner ring pressing sleeve 32 and cannot be removed during the pressing process. At the same time, the distance between the lower end of the limiting post 323 and the bottom of the first positioning shaft 31 is greater than that between the inner ring pressing head 33 and the bearing inner ring. The pressing stroke of the bearing inner ring is designed to ensure that there is always a certain distance between the bottom of the limiting post 323 and the first positioning shaft 31, so as to use the servo displacement curve and pressure value set in the first pressing device 22 to control the pressing of the bearing inner ring and avoid the risk of the bearing inner ring not being pressed in place due to the abutment of the limiting post 323 and the first positioning shaft 31. The sliding connection between the inner ring pressing sleeve 32 and the first support housing 35 is realized by the slider 34 set above the inner ring pressing head 33, so as to use the first pressing device 22 to press the bearing inner ring. To ensure that the bearing inner ring is always subjected to uniform force during the pressing process, a first pressing table 322 connected to the first pressing device 22 is provided on the top of the inner ring pressing sleeve 32. In order to facilitate the pressing of the inner ring pressing sleeve 32 onto the intermediate shaft 13, the outer side of the inner ring pressing head 33 and the inner side of the first support housing 35 have a first space 331 for the bearing inner ring to pass through.Specifically, the operator first places the first pressing fixture 3 on the bearing inner ring and intermediate shaft 13 to be pressed. Under the guidance of the first centering shaft 313, the first positioning shaft 31 connects with the upper surface of the intermediate shaft 13. The outer circle of the first positioning shaft 31 and the bearing inner ring are positioned. The first pressing device 22 starts pressing down. The tip of the first centering shaft 313 and the first positioning shaft 31 press down. Under the action of gravity, the tip guides the intermediate shaft 13. At this time, the inner ring pressing head 33 continues to press down and connects with the bearing inner ring for pressing. At this time, the first positioning shaft exits the pressing, and the intermediate shaft 13 is positioned only by the lower surface of the first centering shaft 313 and the first positioning shaft 31 until the bearing inner ring is pressed into place.

[0058] like Figure 4 , Figure 5 As shown, the second positioning shaft 41 of the second pressing fixture 4 is coaxially arranged with the inner ring of the bearing. To ensure that the outer ring of the bearing is always subjected to uniform force during the pressing process, a second pressing table 42 connected to the first pressing device 22 is provided at the top of the second positioning shaft 41. An outer ring pressing sleeve 43 is fixed at the lower end of the second positioning shaft 41 for pressing the outer ring of the bearing. Specifically, to ensure that the inner ring of the bearing and the intermediate shaft 13 are not affected during the pressing of the outer ring of the bearing, and to ensure the pressing accuracy, a second space 431 for the inner ring of the bearing to pass through is provided inside the outer ring pressing sleeve 43 for the intermediate shaft. 13 passes through the third space 432; to ensure the stability of the second pressing fixture 4 in the reducer housing 1 during the pressing process, a second support housing 45 is slidably provided on the outer side of the outer ring pressing sleeve 43 and connected to the reducer housing 1; to ensure the pressing accuracy of the bearing outer ring, an outer ring pressing head 44 is provided at the lower end of the outer ring pressing sleeve 43 and abuts against the bearing outer ring; to facilitate the placement of the bearing outer ring in the second pressing fixture 4 for pressing, the diameter of the second support housing 45 is adapted to the diameter of the bearing outer ring so that the bearing outer ring can be placed in the second support housing 45 and connected to the outer ring pressing head 44.

[0059] The bearing assembly press-fitting fixture for the automotive drive axle main reducer uses a first press-fitting fixture 3 for pressing the inner bearing ring and a second press-fitting fixture 4 for pressing the outer bearing ring. A first positioning shaft 31, abutting against the intermediate shaft 13, ensures the concentricity of the inner bearing ring and the intermediate shaft 13 during press-fitting. At this time, the lower bottom surface of the first positioning shaft 31 contacts the top surface of the intermediate shaft 13, and the outer circle of the first positioning shaft 31 forms a positioning relationship with the inner bearing ring, thus guaranteeing the concentricity of the inner bearing ring and the central shaft 13. A second positioning shaft 41, coaxially arranged with the inner ring of the bearing, ensures the concentricity of the outer ring of the bearing, the inner ring of the bearing, and the intermediate shaft 13 during the press-fitting of the outer ring of the bearing. Corresponding second spaces 431 and third spaces 432 are provided for the inner ring of the bearing and the intermediate shaft 13 to pass through, so as to avoid the misalignment of the press-fitted inner ring of the bearing and the intermediate shaft 13, thereby further ensuring the press-fitting accuracy of the outer ring of the bearing. This further improves the coaxiality accuracy and assembly stability of the reducer bearing during the assembly process, and ensures the transmission accuracy and bearing life during use.

[0060] To ensure that the first pressing fixture 3 can spring back automatically after pressing for future use, such as... Figure 2 As shown, a spring 324 is sleeved on the outer side of the limiting post 323. One end of the spring 324 abuts against the lower bottom surface of the first pressing table 322, and the other end abuts against the upper top surface of the first positioning shaft 31. Specifically, the operator first places the first pressing fixture 3 on the bearing inner ring and intermediate shaft 13 to be pressed. Under the guidance of the first centering shaft 313, the first positioning shaft 31 connects with the upper surface of the intermediate shaft 13, and the outer circle of the first positioning shaft 31 forms a positioning with the bearing inner ring. The first pressing device 22 starts pressing down, and the tip of the first centering shaft 313 presses down with the first positioning shaft. Under the action of gravity, the tip guides the intermediate shaft 13. At this time, the inner ring pressing head 33 continues to press down and connects with the bearing inner ring for pressing. When the first positioning shaft 31 is removed from the press-fitting process, the intermediate shaft 13 is positioned solely by the first centering shaft 313 and the lower surface of the first positioning shaft 31 until the bearing inner ring is press-fitted into place. During the pressing process, the spring 324 sleeved on the outside of the limiting post 323 is compressed. After the bearing inner ring is press-fitted, the first press-fitting device 22 is lifted upward. At this time, the spring 324 is no longer compressed and rebounds to its original shape, thereby pushing the first press-fitting table 322 to move upward. The first press-fitting table 322 drives the inner ring pressing sleeve 32 to return to its original shape for the next use. Moreover, the setting of the limiting post 323 can ensure that the spring 324 can extend and retract vertically during the press-fitting process, avoiding plastic deformation caused by repeated compression of the spring 324 in the later stage, which would fail to meet the usage requirements.

[0061] To prevent the slider 34 from sliding out of the first support housing 35 during upward sliding, the inner ring pressure head 33 is disengaged from the first positioning shaft 31; such as Figure 2As shown, a first limiting boss 351 is horizontally provided above the first support housing 35. The first limiting boss 351 extends toward the first pressing fixture 3, and the lower bottom surface of the first limiting boss 351 abuts against the upper top surface of the slider 34. A second limiting boss 311 is horizontally provided at the top of the first positioning shaft 31. The second limiting boss 311 extends toward the inner ring pressing head 33, and the lower bottom surface of the second limiting boss 311 abuts against the upper top surface of the inner ring pressing head 33. By setting the first limiting boss 351 to limit the upward sliding distance of the slider 34, and the second limiting boss 311 to limit the relative sliding distance between the inner ring pressing head 33 and the first positioning shaft 31, it is ensured that the slider 34 will not slide out of the first support housing 35, and the first limiting post 323 will not slide out of the inner ring pressing head 33, thus ensuring stable use.

[0062] To limit the downward pressing distance of the second positioning shaft 41 and ensure that the outer ring of the bearing is pressed into the proper position, such as... Figure 4 As shown, a limiting platform 451 is provided above the second support housing 45, which is coaxially arranged with the second positioning shaft 41. The second positioning shaft 41 is slidably disposed in the limiting platform 451. The diameter of the limiting platform 451 is smaller than the diameter of the second support housing 45. The upper top surface of the limiting platform 451 abuts against the lower bottom surface of the second pressing platform 42. By setting the limiting platform 451 to abut against the second pressing platform 42 during the pressing process, the pressing distance of the second positioning shaft 41 is limited, so as to avoid excessive pressing or incomplete pressing.

[0063] To facilitate the press-fitting process, the first positioning shaft 31 of the first press-fitting fixture 3 can be quickly and accurately aligned with the intermediate shaft 13 without misalignment, ensuring the concentricity of the bearing inner ring with the intermediate shaft 13 during press-fitting. Figure 2 As shown, the lower end of the first positioning shaft 31 is provided with a first stop 312 adapted to the intermediate shaft 13; the cross-section of the first stop 312 is tapered, and the first stop 312 can quickly insert the tooling into the bearing, avoiding damage to the bearing or tooling due to incomplete initial insertion, resulting in poor cleanliness. To ensure that the bearing outer ring is placed between the second support housing 45 and the outer ring press head 44 during the pressing of the second press tool 4 on the reducer housing 1, the bearing outer ring will not fall off. Figure 4 As shown, the lower end of the outer ring pressure head 44 is provided with a top spring 441 that is adapted to the outer ring of the bearing. The top spring 441 is used to press and engage the outer ring of the bearing to ensure that the outer ring of the bearing will not fall off.

[0064] To avoid contact wear between the driven gear 131 of stage I and the inner wall of the reducer housing 1 during the pressing process, such as Figure 8 , Figure 9As shown, the bearing assembly press-fitting fixture for the main reducer of the automotive drive axle also includes a limiting plate 5; the limiting plate 5 has a through groove 51 for the intermediate shaft 13 to pass through, and the through groove 51 also has a groove 52 for the placement of the first-stage driven gear 131 in the circumferential direction; the limiting plate 5 also has a hand-held part 53; before pressing down the inner ring 111 of the first bearing, the limiting plate 5 is first inserted into the reducer housing 1 and placed below the first-stage driven gear 131, with the intermediate shaft 13 passing through the through groove 51 and the first-stage driven gear 131 placed in the groove 52, ensuring that the first-stage driven gear 131 will not be damaged due to contact with the limiting plate 5 during the press-fitting process. As a preferred method, to reduce the processing difficulty, such as Figure 9 As shown, the handheld part 53 is a through hole 531 opened on the limiting plate 5; the operator only needs to hold the through hole 531 to pick up and take the limiting plate 5, which is convenient for operation.

[0065] To facilitate the positioning of the reducer housing 1 on the first worktable 2, a positioning base 21 is provided on the first worktable 2. This base is designed to fit the reducer housing 1. Figure 3 , Figure 5 As shown, the lower end of the positioning base 21 is fixed on the first workbench 2. The top of the positioning base 21 is provided with a first limiting ring 211 and a second limiting ring 212. The first limiting ring 211 has a second cavity 213 for the intermediate shaft 13 to pass through. The second limiting ring 212 is arranged around the outside of the first limiting ring 211 and is coaxial with the first limiting ring 211. There is a gap between the second limiting ring 212 and the first limiting ring 211 for positioning the reducer housing 1, and the height of the second limiting ring 212 is lower than that of the first limiting ring 211. Ring 211; By providing a first limiting ring 211 and a second limiting ring 212 on the positioning base 21, and the first limiting ring 211 being adapted to the intermediate shaft 13, the intermediate shaft 13 can penetrate the reducer housing 1 and be inserted into the second cavity 213 in the first limiting ring 211 after being pressed down, so as to limit the position of the intermediate shaft 13 and achieve the purpose of positioning; and the reducer housing is provided with a positioning surface that is clearance-fitted with the second limiting ring 212 to fix the position of the reducer housing 1, so that the intermediate shaft 13 can be lowered into the second cavity 213 of the first limiting ring 211 during the pressing process.

[0066] Furthermore, because both the second bearing 12 and the first bearing 11 are press-fitted inside the reducer housing 1, it is necessary to repeatedly change and retrieve the corresponding bearing parts and suitable press-fitting tooling. This results in a large number of tooling and changeover movements during the press-fitting process, leading to low press-fitting efficiency. To improve press-fitting efficiency, an additional tooling is added to separate the process from a separate press, ensuring workstation balance and increasing the production cycle time of a single process. Figure 6 , Figure 7As shown, the bearing assembly press-fitting fixture for the automotive drive axle main reducer also includes a second worktable 6 for pre-pressing the second bearing 12 onto the intermediate shaft 13. The second worktable 6 has a fixed base 61 and a second press-fitting device 63 located above the fixed base 61. A third press-fitting fixture 7 for press-fitting the second bearing 12 onto the intermediate shaft 13 is fixedly connected below the second press-fitting device 63. A positioning sleeve 62 is detachably mounted on the fixed base 61, and the fixed base 61 has a positioning boss 612. The positioning boss 612 has a positioning groove 613 at its center for fixing the intermediate shaft 13. The bottom of the positioning sleeve 62 has an insertion cavity 621 adapted to the positioning boss 612. Above 621, there is a limiting cavity 622 located inside the positioning sleeve 62, used to fix the second bearing 12 on the intermediate shaft 13. The inner diameter of the limiting cavity 622 is larger than the diameter of the stage II drive gear 132. The third pressing fixture 7 includes a mounting base 71 fixedly connected to the bottom surface of the second pressing device 63. A pressing rod 72 extending downward is fixedly provided below the mounting base 71. The bottom end of the pressing rod 72 is provided with a pressing surface 721 for pressing the second bearing 12. The bottom end of the pressing rod 72 is provided with a second centering shaft 73 extending downward and centeredly connected to the intermediate shaft 13. The end of the second centering shaft 73 facing the intermediate shaft 13 is provided with a tip with a gradually decreasing cross-sectional diameter. The diameter of the second centering shaft 73 is smaller than the diameter of the pressing rod 72.

[0067] After repeated pressing, the pressure surface 6121 of the central shaft 13 and the positioning boss 612 wears, affecting the pressing accuracy. To save costs and replace the positioning boss 612 with a suitable one, such as... Figure 6The structure shown includes a fixed base 61 comprising a positioning boss 612 and a handle section 615. The positioning boss 612 has a positioning groove 613 for fixing the intermediate shaft 13. Two positioning bosses 612 are respectively located at both ends of the handle section 615. The diameter of the handle section 615 is smaller than the diameter of the positioning boss 612. A load-bearing ring plate 614 for placing a positioning sleeve 62 is provided at the connection point between each positioning boss 612 and the handle section 615. The diameter of the load-bearing ring plate 614 is larger than the diameter of the positioning boss 612. The second worktable 6 has an insertion slot adapted to the positioning boss 612. One of the positioning bosses 612 of the fixed base 61 is inserted into the insertion slot of the second worktable 6. Another positioning boss 612, vertically upward, is inserted into the insertion cavity 621 within the positioning sleeve 62, thereby fixing the positioning sleeve 62 onto the second worktable 6 via the fixed base 61. By providing two positioning bosses 612 and inserting them into the second worktable 6, when the pressure surface 6121 of one positioning boss 612 is severely worn, the operator can directly hold the holding section 615, flip the fixed base 61, and flip the other positioning boss 612, which is inserted into the second worktable 6, upward for insertion into the positioning sleeve 62, saving time in replacing the positioning boss 612. Simultaneously, one fixed base 61 can have two positioning bosses 612 for use, saving manufacturing costs. Of course, the positioning groove 613 can be respectively set in the two positioning bosses 612, or... Figure 6 As shown, it is directly installed inside the positioning boss and the hand-held section, which can reduce weight and facilitate processing.

[0068] By designing a second workbench 6, the second bearing 12 is pre-pressed onto the intermediate shaft 13 located within the positioning sleeve 62 using a third pressing fixture 7 and a second pressing device 63. Specifically, after the positioning sleeve 62 is detachably connected to the positioning boss 612 on the fixed base 61 via the insertion cavity 621, the limiting cavity 622 of the positioning sleeve 62 is connected to the positioning groove 613. During operation, the intermediate shaft with the assembled stage II drive gear 132 is first placed in the positioning sleeve 62, and the intermediate shaft 13 is fixed through the positioning groove 613, while simultaneously bearing the downward pressure applied by the third pressing fixture 7 to avoid damaging the positioning sleeve 62. Above the insertion cavity 621, there is a limiting cavity 622 located within the positioning sleeve 62 for fixing the second bearing 12 onto the intermediate shaft 13. The inner diameter of the limiting cavity 622 is greater than that of stage II drive gear 132. The diameter of the stage drive gear 132 is such that the intermediate shaft 13 and the stage II drive gear 132 are not damaged or misaligned during the pressing process; the third pressing fixture 7 includes a mounting base 71 fixedly connected to the bottom surface of the second pressing device 63. Below the mounting base 71 is a pressing rod 72 for pressing the second bearing 12. The pressing rod 72 has a second centering shaft 73 connected to the intermediate shaft 13. The end of the second centering shaft 73 facing the intermediate shaft 13 has a tip with a gradually decreasing cross-sectional diameter. During the pressing process, the tip first enters the intermediate shaft 13 to achieve guiding positioning, guiding the precise positioning and pressing of the second centering shaft 73 and the intermediate shaft 13. The pressing rod 72 moves downward with the second pressing device 63, and after the pressing surface 721 at the lower end of the pressing rod 72 contacts the second bearing 12, it presses down synchronously to prevent the second bearing 12 from shifting during the pressing process; and as Figure 6 As shown, the pressing surface 721 has a chamfer in the circumferential direction to avoid interference between the bearing cage and the tooling, which would affect the pressing process. The internal structure of the pressing rod 72 can be as follows: Figure 2 The connection structure between the first positioning shaft 31 and the inner ring pressure sleeve 32 shown is designed to achieve automatic springback after pressing. A separate second worktable 6 for pre-pressing the second bearing 12 onto the intermediate shaft 13 separates the process of pressing the second bearing 12 onto the intermediate shaft 13, reducing setup and changeover activities and shortening assembly cycle time. It also effectively reduces non-value-adding "empty cuts" and machine movement, reducing motor and data input work; ensuring workstation balance and improving single-process production cycle time. The positioning sleeve 62 and the fixed base 61 can also be detachably connected by a positioning groove 625 and a positioning block 611. Specifically, the positioning block 611 is located on the load-bearing ring plate 614 and can also be connected by tenon and mortise joints, allowing for the replacement of different positioning sleeves 62 to accommodate pressing of intermediate shafts 13 of different sizes.

[0069] To facilitate the insertion of the intermediate shaft 13 equipped with the stage II drive gear 132 into the positioning sleeve 62 and the removal of the positioning sleeve 62 after the intermediate shaft 13 has been press-fitted with the second bearing 12, as follows: Figure 7 As shown, the positioning sleeve 62 has at least two slots 624 on its side that communicate with the limiting cavity; these slots 624 not only facilitate the placement and removal of the intermediate shaft 13, but also allow for real-time observation of whether the second bearing 12 has shifted during the press-fitting process, enabling timely adjustments. To facilitate the handling of the bearing assembly after press-fitting, as... Figure 7 As shown, the top of the positioning sleeve 62 is also provided with a notch 626 for easy access by the operator.

[0070] This invention provides a method for press-fitting bearing assemblies of automotive drive axle final reducers, mainly used for press-fitting bearing assemblies of automotive drive axle final reducers. It employs the aforementioned press-fitting fixture for automotive drive axle final reducers and includes the following steps:

[0071] Step 1: Place the reducer housing 1 on the positioning base 21, and place the first-stage driven gear 131, the second-stage driving gear 132, and the intermediate shaft 13 into the reducer housing 1; Position the reducer housing 1 on the positioning base 21. The outer side of the reducer housing 1 near the first-stage driven gear 131 has a positioning surface adapted to the positioning base 21. Place the first-stage driven gear 131 inside the reducer housing 1, and then place the intermediate shaft 13, which houses the second-stage driving gear 132, inside the reducer housing 1. The other end of the intermediate shaft 13 passes through the first-stage driven gear... Gear 131 abuts against positioning base 21; specifically, to prevent reducer housing 1 from being on positioning base 21, a first limiting ring 211 and a second limiting ring 212 can be provided on the top of positioning base 21. Reducer housing 1 is in clearance fit with the second limiting ring 212 through positioning surface, and the second limiting ring 212 and the end face of reducer housing 1 form an axial positioning surface; the second cavity 213 in the first limiting ring 211 is used for the intermediate shaft 13 to pass through to ensure that the axis of intermediate shaft 13 is coaxial with the pressing equipment to achieve the dual requirements of quick clamping and high-precision positioning of housing.

[0072] Step 2: Press-fit the inner ring 121 of the second bearing; place the inner ring 121 of the second bearing on the intermediate shaft 13 and align it, then place the first pressing fixture 3 on the reducer housing 1. The first positioning shaft 31 of the first pressing fixture 3 is guided and centeredly connected to the intermediate shaft 13 through the guide positioning of the first centering shaft 31. The tip of the first centering shaft 313 is pressed down synchronously with the first positioning shaft 31. Under the action of gravity, the tip 3 guides the intermediate shaft 13 and presses the intermediate shaft 13 onto the stage I driven gear 131. After the inner ring 121 of the second bearing is pressed, remove the first pressing fixture 3. In actual operation, after the first positioning shaft 31 of the first pressing fixture 3 is centered and connected to the intermediate shaft 13 through the first centering shaft 313, the lower end of the first support housing 35 is in contact with the upper surface of the reducer housing 1. During the pressing process, the first support housing 35 is always in contact with the reducer housing 1 to ensure the stability of the inner ring sleeve 32 sliding up and down in the first pressing fixture 3. The first positioning shaft 31, which is slidably set in the inner ring sleeve 32, is centered and connected to the intermediate shaft 13 to ensure the position of the intermediate shaft 13 and the stability when pressing the inner ring 121 of the second bearing, and to avoid pressing offset. The lower end of the first positioning shaft 31 is provided with a first stop 312, which is precisely centered and connected to the intermediate shaft 13 to quickly put the fixture into the bearing, avoiding damage to the bearing or fixture due to the first incomplete placement, resulting in poor cleanliness. The top surface of the first pressing table 322 is pressed down by the first pressing equipment 22, and the bottom surface of the first positioning shaft 31 is in contact with the upper surface of the intermediate shaft 13, and the outer circle of the first positioning shaft 31 is also in contact with the upper surface of the intermediate shaft 13. Positioned with the inner ring 121 of the second bearing, the first pressing device 22 presses down the first pressing fixture 3. At this time, the tip of the first centering shaft 313 presses down synchronously with the first positioning shaft 31. Under the action of gravity, the tip guides the intermediate shaft 13 and presses it onto the stage I driven gear 131. Continuing to press down, the inner ring pressing head 33 continues to press down and engages with the inner ring 121 of the second bearing for pressing. At this time, the first positioning shaft 31 exits the pressing process, and only the first centering shaft 313 and the first positioning head 31 remain in contact. The lower surface of the positioning shaft 31 positions the intermediate shaft 13 until the second bearing inner ring 121 is pressed onto the corresponding position on the intermediate shaft 13. During the pressing process, the spring 324 sleeved on the outside of the limiting post 323 is compressed. After the bearing inner ring is pressed, the first pressing device 22 lifts upward. At this time, the spring 324 is no longer compressed and returns to its original state, thereby pushing the first pressing table 322 to move upward. The first pressing table 322 drives the inner ring pressing sleeve 32 to return to its original state for the next use. It should be noted that the distance between the lower end of the limiting post 323 and the bottom of the first positioning shaft 31 is greater than the pressing stroke of the inner ring pressing head 33 pressing the bearing inner ring. This setting ensures that there is always a certain distance between the limiting post 323 and the bottom of the first positioning shaft 31, so that the pressing of the bearing inner ring can be controlled by the servo displacement curve and pressure value set in the first pressing device 22, avoiding the risk of the bearing inner ring not being pressed into place due to the limiting post 323 abutting against the first positioning shaft 31.

[0073] Step 3: Press-fit the second bearing outer ring 122; Place the second bearing outer ring 122 inside the second support housing 45 of the second pressing fixture 4 and connect it with the outer ring pressing head 44 of the second pressing fixture 4. Then place the second pressing fixture 4 on the reducer housing 1 and place it above the already pressed-fit second bearing inner ring 121 and coaxially with the intermediate shaft 13. The first pressing device 22 presses down the second pressing fixture 4, driving the outer ring pressing head 44 of the second pressing fixture 4 to press down the second bearing outer ring 122 and press the second bearing outer ring 122 onto the second bearing inner ring 121. After the second bearing outer ring 122 is pressed, remove the second pressing fixture 4. In actual operation, after the operator presses in the inner ring 121 of the second bearing, the first pressing fixture 3 is removed, and the outer ring 122 of the second bearing is placed inside the second support housing 45 of the second pressing fixture 4 and connected to the outer ring pressing head 44. Then, the second pressing fixture 4 with the outer ring 122 placed is placed on the reducer housing 1, and the second support housing 45 is connected to the reducer housing 1. At this time, the first pressing device 22 presses down and connects with the second pressing table 42, and the second positioning shaft 41 is coaxial with the inner ring 121 of the second bearing. The second positioning shaft 41 is pressed down together with the second pressing table 42. At this time, the pressed-up second bearing inner ring 121 enters the second space 431 set in the outer ring pressing sleeve 43, and the intermediate shaft 13 enters the third space 432 set in the outer ring pressing sleeve 43. This avoids the already pressed-up second bearing inner ring 121 and intermediate shaft 13 from shifting, and at the same time plays a positioning pressing role, ensuring that the second bearing outer ring 122 is accurately pressed on the outside of the second bearing inner ring 121. After pressing is completed, the second pressing fixture 4 is removed.

[0074] Step 4: Flip the reducer housing 1; after pressing the second bearing inner ring 121 and the second bearing outer ring 122, flip the reducer housing 1 so that the side of the reducer housing 1 closest to the first stage driven gear 131 faces the first pressing device 22; after flipping the reducer housing 1, the end of the intermediate shaft 13 passing through the reducer housing 1 needs to be inserted into the second cavity 213 of the first limiting ring 211 on the positioning base 21 to achieve positioning installation, so as to ensure concentricity when pressing the first bearing inner ring 111 later.

[0075] Step 5: Press-fit the first bearing inner ring 111; Place the first bearing inner ring 111 on the intermediate shaft 13 and align it. Then place the first pressing fixture 3 on the reducer housing 1. The first positioning shaft 31 of the first pressing fixture 3 is centeredly connected to the intermediate shaft 13. The first pressing device 22 presses down the first pressing fixture 3, driving the inner ring pressing head 33 of the first pressing fixture 3 to press down the first bearing inner ring 111, pressing the first bearing inner ring 111 onto the intermediate shaft 13. At the same time, the limiting post 323 below the first pressing table 322 of the first pressing fixture 3 presses down and engages with the first positioning shaft 3. 1. After the first bearing inner ring 111 is press-fitted, the first press-fit fixture 3 is removed. After the first positioning shaft 31 of the first press-fit fixture 3 is centered and connected to the intermediate shaft 13, the lower end of the first support housing 35 is in contact with the upper surface of the reducer housing 1. During the press-fitting process, the first support housing 35 is always in contact with the reducer housing 1 to ensure the stability of the inner ring sleeve 32 sliding up and down in the first press-fit fixture 3. The first positioning shaft 31, which is slidably set in the inner ring sleeve 32, is centered and connected to the intermediate shaft 13 by the guide positioning of the top end of the first centering shaft 313. To ensure the position of the intermediate shaft 13 and the stability during the press-fitting of the inner ring 111 of the first bearing, and to prevent press-fitting misalignment, the lower end of the first positioning shaft 31 is provided with a first stop 312 and a first centering shaft 313 with a tip, so as to quickly and accurately center and connect with the intermediate shaft 13 to ensure stability. The top surface of the first pressing table 322 is pressed down by the first pressing equipment 22, and the limiting post 323 set on the lower surface of the first pressing table 322 abuts against the first positioning shaft 31 to prevent the first positioning shaft 31 from misaligning, and the first pressing table 322 drives the inner ring pressing sleeve 32 to slide. When pressed down, the inner ring pressure head 33 at the lower end of the inner ring pressure sleeve 32 abuts against the inner ring 111 of the first bearing, stably pressing the inner ring 111 of the first bearing onto the intermediate shaft 13 without any displacement. During the pressing process, the spring 324 sleeved on the outside of the limiting post 323 is compressed. After the inner ring 111 of the first bearing is pressed, the first pressing device 22 is lifted upward. At this time, the spring 324 is no longer compressed and rebounds to its original state, thereby pushing the first pressing table 322 to move upward. The first pressing table 322 drives the inner ring pressure sleeve 32 to return to its original state for the next use.

[0076] Step Six: Press-fit the first bearing outer ring 112; Place the first bearing outer ring 112 inside the second support housing 45 of the second pressing fixture 4 and connect it with the outer ring pressing head 44 of the second pressing fixture 4. Then place the second pressing fixture 4 on the reducer housing 1 and position it above the already pressed-fitted first bearing inner ring 111 and coaxial with the intermediate shaft 13; The first pressing device 22 presses down the second pressing fixture 4, driving the outer ring pressing head 44 of the second pressing fixture 4 to press down the first bearing outer ring 112, pressing the first bearing outer ring 112 onto the first bearing inner ring 111; After the first bearing outer ring 112 is pressed, remove the first pressing fixture 3; In actual operation, after pressing the first bearing inner ring 111, the operator removes the first pressing fixture 3 and places the first bearing outer ring 112 on the second support housing 45 of the second pressing fixture 4. The inner ring is connected to the outer ring pressure head 44, and the second pressing fixture 4, in which the first bearing outer ring 112 is placed, is placed on the reducer housing 1. The second support housing 45 is connected to the reducer housing 1. At this time, the first pressing device 22 presses down and connects with the second pressing table 42. The second positioning shaft 41 is coaxially set with the first bearing inner ring 111. The second positioning shaft 41 is pressed down together with the second pressing table 42. At this time, the pressed first bearing inner ring 111 enters the second space 431 set in the outer ring pressure sleeve 43, and the intermediate shaft 13 enters the third space 432 set in the outer ring pressure sleeve 43. This avoids the first bearing inner ring 111 and the intermediate shaft 13 that have been pressed down and causing them to shift. At the same time, it plays a positioning pressing role to ensure that the first bearing outer ring 112 is accurately pressed on the outside of the first bearing inner ring 111. After pressing is completed, the second pressing fixture 4 is removed.

[0077] Complete the press-fitting of the bearing assembly of the main reducer of the automotive drive axle.

[0078] This invention provides a method for press-fitting bearing assemblies in a vehicle drive axle main reducer. Based on the aforementioned bearing assembly press-fitting fixture, it achieves rapid and precise press-fitting of the reducer bearing, improving the coaxiality accuracy and assembly stability of the reducer bearing during assembly, and ensuring transmission accuracy and bearing life during use. Specifically, by setting corresponding first press-fitting fixture 3 for press-fitting the inner ring of the bearing and second press-fitting fixture 4 for press-fitting the outer ring of the bearing, and by using a first positioning shaft 31 that abuts against the intermediate shaft 13, the concentricity of the inner ring of the bearing and the intermediate shaft 13 is ensured during the press-fitting of the inner ring of the bearing. After the limiting post 323 in the cavity 321 abuts against the first positioning shaft 31, it can press the intermediate shaft 13 down to the corresponding position, realize the synchronous pressing of the intermediate shaft 13 and the bearing inner ring, and ensure concentricity. The second positioning shaft 41, which abuts against the bearing inner ring and is coaxially arranged, ensures the concentricity of the bearing outer ring, the bearing inner ring, and the intermediate shaft 13 when pressing the bearing outer ring. The second space 431 and the third space 432 are provided for the bearing inner ring and the intermediate shaft 13 to pass through to avoid the bearing inner ring and the intermediate shaft 13 from shifting after pressing, and further ensure the pressing accuracy of the bearing outer ring.

[0079] Furthermore, since both the second bearing 12 and the first bearing 11 are press-fitted inside the reducer housing 1, it is necessary to repeatedly change and retrieve the corresponding bearing parts and suitable press-fitting fixtures. This results in a large number of fixtures and frequent changeovers during the press-fitting process, leading to low press-fitting efficiency. To improve press-fitting efficiency, an additional fixture is added to separate the process from a separate press, ensuring workstation balance and increasing the production cycle time of a single process. The bearing assembly press-fitting fixture for the automotive drive axle main reducer also includes a second worktable 6, on which a fixed base 61 is provided. The second worktable 6 also has a second press-fitting fixture located above the fixed base 61. The device 63; a third pressing fixture 7 for pressing the second bearing 12 onto the intermediate shaft 13 is fixedly connected below the second pressing device 63; before the first step, the second bearing 12 is pre-pressed, and the intermediate shaft 13, which is integrally formed with the stage II drive gear 132, is placed in the positioning sleeve 62 of the fixed base 61 on the second worktable 6. The second pressing device 63 presses down, driving the pressing rod 72 of the third pressing fixture 7 to press down. The centering shaft 73 of the pressing rod 72 is centered and connected to the intermediate shaft 13 through the guide positioning of the tip. The pressing surface 721 of the pressing rod 72 presses the second bearing 12 onto the intermediate shaft 13.

[0080] During the pre-pressing process of the second bearing 12, the positioning sleeve 62 is detachably connected to the positioning boss 612 on the fixed base 61 through the insertion cavity 621. The limiting cavity 622 of the positioning sleeve 62 then communicates with the positioning groove 613. During operation, the intermediate shaft 13, with the second-stage drive gear 132 already assembled, is first placed in the positioning sleeve 62. The lower end of the intermediate shaft 13 is inserted into the positioning groove 613 on the positioning boss 612 to fix the intermediate shaft 13. The diameter of the second-stage drive gear 132 is smaller than the inner diameter of the limiting cavity 622 in the positioning sleeve 62, so the second-stage drive gear 132 can be placed in the positioning sleeve 62 along with the central shaft 13. Then, the second bearing 12 is placed on the upper end of the intermediate shaft 13, with its lower end connected to the limiting cavity 622, ensuring the concentricity of the second bearing 12 with the intermediate shaft 13 during the press-fitting process and preventing any misalignment. At this point, the operator... The second pressing device 63 drives the third pressing fixture 7 to press down. The pressing rod 72 of the third pressing fixture 7 presses down, and the centering shaft 73 of the pressing rod 72 is centered and connected to the intermediate shaft 13. The pressing surface 721 of the pressing rod 72 presses the second bearing 12 onto the intermediate shaft 13. Furthermore, through the separately set second worktable 6 for pre-pressing the second bearing 12 onto the intermediate shaft 13, the process of pressing the second bearing 12 onto the intermediate shaft 13 is separated, reducing the actions during setup and changeover activities, and shortening the assembly cycle time. It can also effectively reduce non-value-adding "empty cuts" and machine movements, reduce motor and data input work, ensure the workstation balance rate, and improve the production cycle time of a single process.

[0081] To prevent contact wear between the first-stage driven gear 131 and the inner wall of the reducer housing 1 during the pressing process, the bearing assembly press-fitting fixture of the automotive drive axle main reducer also includes a limiting plate 5; the limiting plate 5 has a through groove 51 for the intermediate shaft 13 to pass through, and the through groove 51 also has a groove 52 for placing the first-stage driven gear in the circumferential direction, and the limiting plate 5 also has a hand-held part 53; before step two, the limiting plate 5 is placed; the through groove 51 of the limiting plate 5 passes through the intermediate shaft 13 set in the reducer housing 1, and the limiting plate 5 is placed between the first-stage driven gear 131 and the reducer housing 1.

Claims

1. A press-fitting fixture for a bearing assembly of a main reducer in an automotive drive axle, characterized in that: Includes a first workbench (2), on which a positioning base (21) for fixing the reducer housing (1) is provided, and on which a first pressing device (22) is located above the positioning base (21) is also provided. It also includes a first press-fitting fixture (3) for press-fitting the inner ring of the bearing onto the intermediate shaft (13) and a second press-fitting fixture (4) for press-fitting the outer ring of the bearing onto the outer side of the inner ring of the bearing. The first press-fitting fixture (3) includes a first positioning shaft (31) that abuts against and is coaxially arranged with the intermediate shaft (13). The lower end of the first positioning shaft (31) is provided with a first centering shaft (313) that is adapted to the intermediate hole of the intermediate shaft (13). The lower end of the first centering shaft (313) is provided with a top part with a gradually decreasing cross-sectional diameter. An inner ring press sleeve (32) with a first cavity (321) is slidably connected to the outer side of the first positioning shaft (31). The outer side of the inner ring press sleeve (32) is slidably connected to a first support housing (35) that is connected to the reducer housing (1). The top of the sleeve (32) is provided with a first pressing table (322) that is connected to the first pressing device (22). The lower surface of the first pressing table (322) is fixed with a limiting post (323) located in the first cavity (321). The lower end of the inner ring pressing sleeve (32) is provided with an inner ring pressing head (33) that abuts against the inner ring of the bearing. There is a first space (331) between the outer side of the inner ring pressing head (33) and the inner side of the first support housing (35) for the inner ring of the bearing to pass through. Above the inner ring pressing head (33) is a slider (34) that is slidably connected to the inner side of the first support housing (35). The second press-fitting fixture (4) includes a second positioning shaft (41) coaxially arranged with the inner ring of the bearing. The top of the second positioning shaft (41) is provided with a second press-fitting table (42) connected to the first press-fitting equipment (22). The lower end of the second positioning shaft (41) is fixedly provided with an outer ring press sleeve (43). The inner side of the outer ring press sleeve (43) is provided with a second space (431) for the inner ring of the bearing to pass through. The outer ring press sleeve (43) is also provided with a third space (432) connected to the second space (431) and for the intermediate shaft (13) to pass through. The lower end of the outer ring press sleeve (43) is provided with an outer ring press head (44) connected to the outer ring of the bearing. The outer side of the outer ring press sleeve (43) is slidably connected with a second support housing (45) connected to the reducer housing (1). The diameter of the second support housing (45) is adapted to the diameter of the outer ring of the bearing to place the outer ring of the bearing in the second support housing (45) and connect with the outer ring press head (44).

2. The bearing assembly press-fitting fixture for an automotive drive axle main reducer as described in claim 1, characterized in that: A spring (324) is sleeved on the outside of the limiting post (323). One end of the spring (324) abuts against the bottom surface of the first pressing table (322), and the other end abuts against the top surface of the first positioning shaft (31).

3. The bearing assembly press-fitting fixture for an automotive drive axle main reducer as described in claim 1, characterized in that: A first limiting boss (351) is provided horizontally above the first support housing (35). The first limiting boss (351) extends toward the first press-fit workpiece and the bottom surface of the first limiting boss (351) abuts against the top surface of the vertical guide mechanism. The top of the first positioning shaft (31) is provided with a second limiting boss (311), which extends toward the inner ring pressure head (33) and the bottom surface of the second limiting boss (311) abuts against the top surface of the inner ring pressure head (33).

4. The bearing assembly press-fitting fixture for an automotive drive axle main reducer as described in claim 1, characterized in that: The second support housing (45) is provided with a limiting platform (451) coaxially arranged with the second positioning shaft (41) on the upper part. The second positioning shaft (41) is slidably arranged in the limiting platform (451). The diameter of the limiting platform (451) is smaller than the diameter of the second support housing (45). The upper top surface of the limiting platform (451) abuts against the lower bottom surface of the second pressing platform (42).

5. The bearing assembly press-fitting fixture for an automotive drive axle main reducer as described in claim 1, characterized in that: It also includes a limiting plate (5); the limiting plate (5) has a through groove (51) for the intermediate shaft (13) to pass through, and the through groove (51) is also provided with a groove (52) for the placement of the first stage driven gear (131) in the circumferential direction. The limiting plate (5) is also provided with a hand-held part (53); the hand-held part (53) is a through hole (531) opened on the limiting plate (5).

6. The bearing assembly press-fitting fixture for an automotive drive axle main reducer as described in claim 1, characterized in that: The lower end of the positioning base (21) is fixed on the first workbench (2). The top of the positioning base (21) is provided with a first limiting ring (211) and a second limiting ring (212). The first limiting ring (211) is provided with a second cavity (213) for the intermediate shaft (13) to pass through. The second limiting ring (212) is arranged around the outside of the first limiting ring (211) and is coaxial with the first limiting ring (211). There is a gap between the second limiting ring (212) and the first limiting ring (211) for positioning the reducer housing (1), and the height of the second limiting ring (212) is lower than that of the first limiting ring (211).

7. A bearing assembly press-fitting fixture for an automotive drive axle main reducer as described in any one of claims 1-6, characterized in that: It also includes a second worktable (6) for pre-pressing the second bearing (12) onto the intermediate shaft (13), the second worktable (6) is provided with a fixed base (61), and the second worktable (6) is also provided with a second pressing device (63) located above the fixed base (61); a third pressing fixture (7) for pressing the second bearing (12) onto the intermediate shaft (13) is fixedly connected below the second pressing device (63); A positioning sleeve (62) is detachably installed on the fixed base (61). The fixed base (61) is provided with a positioning boss (612). The positioning boss (612) has a positioning groove (613) for fixing the intermediate shaft (13) in the center. The bottom of the positioning sleeve (62) is provided with an insertion cavity (621) that matches the positioning boss (612). Above the insertion cavity (621) is a limiting cavity (622) located inside the positioning sleeve (62) for fixing the second bearing (12) on the intermediate shaft (13). The inner diameter of the limiting cavity (622) is larger than the diameter of the stage II drive gear (132). The third pressing fixture (7) includes a mounting base (71) fixedly connected to the bottom surface of the second pressing device (63). A pressing rod (72) extending downward is fixedly provided below the mounting base (71). The bottom end of the pressing rod (72) is provided with a pressing surface (721) for pressing the second bearing (12). The bottom end of the pressing rod (72) is provided with a second centering shaft (73) extending downward and centering connected to the intermediate shaft (13). The end of the second centering shaft (73) facing the intermediate shaft (13) is provided with a tip with a gradually decreasing cross-sectional diameter. The diameter of the second centering shaft (73) is smaller than the diameter of the pressing rod (72).

8. A method for press-fitting a bearing assembly of a vehicle drive axle final reducer, characterized in that: The bearing assembly press-fitting fixture for the automotive drive axle final reducer as described in any one of claims 1-7 includes the following steps: Step 1: Place the reducer housing (1) on the positioning base (21), and place the first stage driven gear (131), the second stage driving gear (132), and the intermediate shaft (13) into the reducer housing (1); The reducer housing (1) is positioned on the positioning base (21). The reducer housing (1) has a positioning surface that is compatible with the positioning base (21) on the outer side of the end near the first stage driven gear (131). The first stage driven gear (131) is placed inside the reducer housing (1). Then, the intermediate shaft (13) with the second stage driving gear (132) is placed inside the reducer housing (1). The other end of the intermediate shaft (13) passes through the first stage driven gear (131) and abuts against the positioning base (21). Step 2: Press-fit the inner ring of the second bearing (121); The second bearing inner ring (121) is placed on the intermediate shaft (13) and aligned. Then, the first pressing fixture (3) is placed on the reducer housing (1). The first positioning shaft (31) of the first pressing fixture (3) is centered and connected to the intermediate shaft (13). The first pressing device (22) presses down the first pressing fixture (3) and drives the inner ring pressing head (33) of the first pressing fixture (3) to press down the second bearing inner ring (121) and press the second bearing inner ring (121) onto the intermediate shaft (13). The tip of the first centering shaft (313) presses down synchronously with the first positioning shaft (31). Under the action of gravity, the tip guides the intermediate shaft (13) and presses the intermediate shaft (13) onto the first stage driven gear (131). After the second bearing inner ring (121) is pressed down, the first pressing fixture (3) is removed. Step 3: Press-fit the outer ring of the second bearing (122); Place the outer ring (122) of the second bearing inside the second support housing (45) of the second press-fitting fixture (4) and connect it with the outer ring press head (44) of the second press-fitting fixture (4). Then place the second press-fitting fixture (4) on the reducer housing (1) and place it above the already press-fitted inner ring (121) of the second bearing and coaxial with the intermediate shaft (13). The first press-fitting device (22) presses down the second press-fitting fixture (4) and drives the outer ring press head (44) of the second press-fitting fixture (4) to press down the outer ring (122) of the second bearing and press the outer ring (122) onto the inner ring (121) of the second bearing. After the outer ring (122) of the second bearing is press-fitted, remove the second press-fitting fixture (4). Step 4: Flip the reducer housing (1); After pressing the inner ring (121) and outer ring (122) of the second bearing, flip the reducer housing (1) so that the side of the reducer housing (1) closest to the first stage driven gear (131) faces the first pressing device (22). Step 5: Press-fit the inner ring of the first bearing (111); Place the inner ring (111) of the first bearing on the intermediate shaft (13) and align it. Then place the first press-fit fixture (3) on the reducer housing (1). The first positioning shaft (31) of the first press-fit fixture (3) is centered and connected to the intermediate shaft (13). The first press-fitting device (22) presses down the first press-fitting fixture (3) and drives the inner ring press head (33) of the first press-fitting fixture (3) to press down the inner ring (111) of the first bearing and press the inner ring (111) onto the intermediate shaft (13). At the same time, the limiting post (323) under the first press-fitting table (322) of the first press-fitting fixture (3) presses down and abuts against the first positioning shaft (31). After the inner ring (111) of the first bearing is press-fitted, the first press-fitting fixture (3) is removed. Step 6: Press-fit the outer ring of the first bearing (112); Place the outer ring (112) of the first bearing inside the second support housing (45) of the second press-fitting fixture (4) and connect it with the outer ring press head (44) of the second press-fitting fixture (4). Then place the second press-fitting fixture (4) on the reducer housing (1) and place it above the already press-fitted inner ring (111) of the first bearing and coaxial with the intermediate shaft (13). The first press-fitting device (22) presses down the second press-fitting fixture (4) and drives the outer ring press head (44) of the second press-fitting fixture (4) to press down the outer ring (112) of the first bearing and press the outer ring (112) onto the inner ring (111) of the first bearing. After the outer ring (112) of the first bearing is press-fitted, remove the first press-fitting fixture (3). Complete the press-fitting of the bearing assembly of the main reducer of the automotive drive axle.

9. A method for press-fitting a bearing assembly of a vehicle drive axle main reducer as described in claim 8, characterized in that: The bearing assembly press-fitting fixture of the main reducer of the automobile drive axle also includes a second worktable (6), a fixed base (61) is provided on the second worktable (6), and a second press-fitting device (63) located above the fixed base (61) is also provided on the second worktable (6); a third press-fitting fixture (7) for press-fitting the second bearing onto the intermediate shaft (13) is fixedly connected below the second press-fitting device (63). Before step one, a second bearing pre-pressing is also included. The intermediate shaft (13) integrated with the stage II drive gear (132) is placed in the positioning sleeve (62) of the fixed base (61) on the second worktable (6). The lower end of the intermediate shaft (13) is inserted into the positioning groove (613). The second pressing device (63) presses down and drives the pressing rod (72) of the third pressing tool (7) to press down. The second centering shaft (73) of the pressing rod (72) is centered and connected to the intermediate shaft (13). The pressing surface (721) of the pressing rod (72) presses the second bearing (12) onto the intermediate shaft (13).

10. A method for press-fitting a bearing assembly of a vehicle drive axle main reducer as described in claim 8, characterized in that: The bearing assembly press-fitting fixture of the main reducer of the automobile drive axle also includes a limiting plate (5); the limiting plate (5) is provided with a through groove (51) for the intermediate shaft (13) to pass through, and the through groove (51) is also provided with a groove (52) for the placement of the driven gear in the circumferential direction, and the limiting plate (5) is also provided with a hand-held part (53). Before step two, a limiting plate (5) is placed; the through groove (51) of the limiting plate (5) passes through the intermediate shaft (13) set in the reducer housing (1) and places the limiting plate (5) between the first stage driven gear (131) and the reducer housing (1).

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