CN110939710A

CN110939710A - Shaft hole sealing structure of differential half shaft gear and machining process

Info

Publication number: CN110939710A
Application number: CN201911399291.5A
Authority: CN
Inventors: 王东; 张婧
Original assignee: SICHUAN ZHONGYOU MACHINERY CO Ltd
Current assignee: SICHUAN ZHONGYOU MACHINERY CO Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-03-31

Abstract

A shaft hole sealing structure of a differential half shaft gear and a processing technology are provided to improve the processing precision and the processing efficiency of the half shaft gear with a closed end. The shaft hole sealing structure of the differential half shaft gear comprises a gear body and a plurality of gear teeth uniformly distributed at one end of the gear body, and a shaft hole is formed along the axis of the gear body; the shaft hole through gear body the shaft hole is located the teeth of a cogwheel one end and is equipped with coaxial pressure equipment hole, and pressure equipment hole aperture is greater than the shaft hole aperture, be equipped with the oil blanket lid in the pressure equipment hole, both constitute the tight fit, oil blanket lid outward flange and pressure equipment hole pore wall constitute laser welding and are connected. According to the sealing process for press fitting by using the gear and the oil seal cover component and welding on the surface of the component, all machining before press fitting of the gear can be completed according to a conventional process, so that the production efficiency is greatly improved, and the machining difficulty and the production cost are reduced.

Description

Shaft hole sealing structure of differential half shaft gear and machining process

Technical Field

The invention relates to a sealing structure of a shaft hole or shaft hole of a semi-shaft gear for a differential mechanism and a processing technology.

Background

With the progress and development of automobile manufacturing, the requirements of automatic transmissions are higher and higher, the structures of the automatic transmissions are more and more complex, and the internal parts are updated. Self-sealing differential mechanisms have been increasingly developed and widely used in recent years. The self-sealing structure differential mechanism requires the shaft hole end face of the gear tooth end axle center of the differential mechanism half axle gear to be sealed, so that no impurities exist in the differential mechanism shell, lubricating oil in the differential mechanism shell can be recycled, and the lubricating effect is good.

In the prior art, a sealing mode of a rubber plug is usually adopted for processing or obtaining a differential half-shaft gear with a sealed gear tooth end face, but the rubber plug has a falling risk under high impact, and is easy to deform and has an oil leakage risk under a high-temperature environment. The manufacturing process of the blind hole type structure comprises the following steps: when machining, the shaft hole in the end face of the half axle gear is not turned through, and the sealing performance of the gear is ensured by adopting a mode that the spline is extruded by the blind hole. However, the process has the disadvantages of extremely high processing difficulty, extremely high cost and low yield, and cannot meet the increasing requirements of the automobile industry.

Disclosure of Invention

The invention aims to provide a shaft hole sealing structure of a differential side gear and a machining process, so as to improve the machining precision and the machining efficiency of the side gear with a closed end.

The technical scheme adopted by the invention is as follows: a shaft hole sealing structure of a differential half shaft gear comprises a gear body and a plurality of gear teeth uniformly distributed at one end of the gear body, wherein a shaft hole is formed along the axis of the gear body; the shaft hole through gear body the shaft hole is located the teeth of a cogwheel one end and is equipped with coaxial pressure equipment hole, and pressure equipment hole aperture is greater than the shaft hole aperture, be equipped with the oil blanket lid in the pressure equipment hole, both constitute the tight fit, oil blanket lid outward flange and pressure equipment hole pore wall constitute laser welding and are connected.

Correspondingly, the machining process of the shaft hole sealing structure of the differential side gear comprises the following steps:

1) machining: machining the half axle gear, wherein the machining comprises machining a through shaft hole, a press-fitting inner hole is formed in the end of a gear tooth of the shaft hole, and then surface treatment is carried out to obtain a finished half axle gear; selecting a material which is the same as the half axle gear, and machining an oil seal cover; in the machining, the oil seal cover and the press-fitting inner hole form close fit for machining;

2) removing the carburized layer: turning off a carburized layer on the inner wall of a press-fitting inner hole of the half-shaft gear;

3) press fitting: after thorough cleaning, press-fitting the oil seal cover into the press-fitting inner hole;

4) laser welding: and (5) performing laser welding on the workpiece which is qualified in press mounting by using a special laser welding device.

The invention has the beneficial effects that: the process adopts the sealing process of press-mounting the gear and the oil seal cover component and welding the surface of the component, and the machining before the press-mounting of the gear can be finished according to the conventional process, thereby greatly improving the production efficiency and reducing the machining difficulty and the production cost. The effective welding depth of the process can reach 1.2-1.5 mm, the gear assembly can bear the air pressure of more than 10Bar, the air leakage and the loosening can be avoided, the pressure is maintained for more than 25s under the pressure of 90 +/-3 KPa, the leakage amount is lower than 22.4Pa, and the sealing effect of the gear assembly in a gearbox is ensured.

Drawings

FIG. 1 is a schematic view of the shaft hole sealing structure of the present invention;

FIG. 2 is a schematic view of the oil seal cover of the present invention;

fig. 3 is a schematic view of a press-fitting apparatus of the present invention;

FIG. 4 is a schematic view of the construction of the laser welding apparatus of the present invention;

FIG. 5 is a schematic diagram of a preferred embodiment of a special fixture of the laser welding device;

FIG. 6 is a schematic view of FIG. 5 with parts broken away;

FIG. 7 is a schematic view of the nozzle ring of FIG. 5 being moved laterally by a first cylinder.

Detailed Description

The technical solution of the patent is further explained by the following examples in conjunction with the attached drawings. So that the technical solution and concept of the present invention will be more apparent to those skilled in the art.

Structure of the invention

The shaft hole sealing structure of the differential half shaft gear comprises a gear body 1, wherein the gear body 1 comprises a gear end and a gear shaft end, a plurality of gear teeth 2 are uniformly distributed at the gear end, a shaft hole 3 is formed in the gear body 1 along the axis, and spline grooves or spline teeth are arranged in the shaft hole 3 and used for being connected with a rotating shaft. The shaft hole 3 penetrates through the gear body 1, and a coaxial press-fitting inner hole 4 is formed in one end, located on the gear teeth 2, of the shaft hole 3. Further, the shaft hole 3 is sequentially provided with a press-fitting inner hole 4, a large pipe diameter part 6, spline teeth 7 and a stepped hole part from one end of the gear tooth 2 to the other end, and the diameter of the stepped hole part is sequentially increased in the direction far away from the press-fitting inner hole 4. And annular grooves 8 are respectively formed at the positions of the spline teeth 7 close to the press-fitting inner holes 4 and the positions of the stepped hole parts closest to the end parts. The specific hole diameter of the stepped hole part and the length and shape of each part are determined according to the rotating shaft connected inside.

During the assembly of automobile assembly, be close to the interior installation jump ring of ring channel 8 of pressure equipment hole 4 department, the effect is the axial removal of fixed integral key shaft, and the integral key shaft inserts into the jump ring and fixes the spline, can't advance again, and need just can pull out with energetically and take off. The annular groove 8 close to the end part of the stepped hole, namely the lower end of the figure 1 is internally provided with a sealing ring, so that the lubricating effect of the rotating shaft and the inside of the gear is ensured, and the abrasion of the spline shaft is reduced. The lubricating oil of the part comes from a through hole on the wall of the shaft hole 3 of the gear body 1 or a hole of the rotating shaft along the axial center and the circumferential direction, and is specifically designed according to the integral structure of the differential. The large diameter portion 6 may be used to buffer a portion of the lubricant; and the sealing of the oil seal cover 5 is buffered as an independent sealing chamber, so that the sealing of the oil seal cover 5 is more reliable.

The hole diameter of the press-fitting inner hole 4 is larger than that of the shaft hole 3, the oil seal cover 5 is arranged in the press-fitting inner hole 4, the press-fitting inner hole and the oil seal cover form tight fit, the tight fit is transition fit or tiny clearance fit, and the tight fit cannot fall out only by the dead weight of the oil seal cover 5 under the action of no external force. The outer edge of the oil seal cover 5 is connected with the hole wall of the press-fitting inner hole 4 in a laser welding mode. The effective welding depth in the structure of the invention can reach 1.2-1.5 mm, the gear assembly can bear the air pressure of more than 10Bar without air leakage and release, the pressure is maintained for more than 25s under the pressure of 90 +/-3 KPa, the leakage amount is lower than 22.4Pa, and the sealing effect in the gearbox is ensured.

Preferably, the edge of the lower end face of the oil seal cover 5 and the edge of the upper end of the press-fitting inner hole 4 are provided with a rounding or chamfer. Therefore, the oil seal cover 5 is convenient to mount and position, the tip part is avoided, the local stress concentration is avoided, and the service life of the product is prolonged. The distance L between the root of the gear tooth 2 and the hole wall of the press-fitting inner hole 4 is 5-8mm as shown in figure 1. Avoid factors such as welding heat to influence teeth of a cogwheel 2 structure and performance, also let the semi-axis gear base member that sets up teeth of a cogwheel 2 thicker, avoid teeth of a cogwheel root stress concentration. The tooth spaces 6 between the roots of the adjacent gear teeth 2 are ship-shaped grooves with two high ends and a low middle part. The ship-shaped groove can enable the root bases at two ends of the gear teeth 2 to be deeper, and the ship-shaped or arc-shaped profile of the root bottom of the gear teeth 2 also avoids stress concentration caused by linear intersection of two surfaces; and the ship-shaped part can contain more lubricating grease, so that the lubricating effect is improved, and the gear wear is reduced.

The processing technology of the structure comprises the following steps:

1. press mounting of gear and oil seal cover

To process the diameter

The side gear with the inner hole 4 pressed with the depth of 4.2 +/-0.1 is taken as an example.

① choice of material

The materials of the side gear and the oil seal cover 5 are required to be consistent, and when two different materials are welded, because the contents of elements such as carbon, sulfur, phosphorus and the like are different, the respective melting points are different, the solidification speeds are different, and the probability of generating cracks is very high.

② machining

Machining the half axle gear, wherein a through hole is machined to serve as a shaft hole 3, a press-fitting inner hole 4 is formed in the end, at the end of the gear tooth 2, of the shaft hole 3, and then surface treatment is carried out to obtain a finished half axle gear;

before press fitting, a press fitting inner hole 4 connected with the oil seal cover 5 needs to be turned to remove a carburized layer, and the depth of the carburized layer is 0.8-1.2mm on a single side generally. By the final finished size of the inner bore

For example, the machining dimension before carburizing should be φ 31. + -. 0.03.

The carburized layer in the area is removed, so that carbon elements and impurities are removed, the cracking phenomenon in the welding process is reduced, and the fusion of the gear and the oil seal cover is facilitated.

③ size fit of press-fitting inner hole and oil seal cover 5

The final finished product size of the press-fitting inner hole 4 is

For example, the hole depth is 4.2 + -0.1, the outer diameter of the oil seal cover 5 should be the same as that of the oil seal cover

Height

(as shown in fig. 2), the clearance between the press-fitting inner hole 4 and the oil seal cover 5 is not too large, and is properly controlled to be 0.05-0.09 mm.

④ cleaning gear and oil seal

Before the side gear and the oil seal cover 5 are pressed, the side gear and the oil seal cover must be cleaned, the cleanliness standard is implemented according to Q/JLPB140517B-2016, and the ratio of the side gear: 0.5 mg/piece, the specification of a filter screen is 41 mu m; maximum size requirement for individual contaminants: metal 600 μm, non-metal: 1200 μm.

And (5) oil seal cover: less than or equal to 1.2 mg/piece, and the size of the filter screen is 41 mu m. After the welding head is cleaned, other substances such as rust-proof oil and the like cannot be smeared, otherwise, during welding, due to high temperature, surface substances are vaporized to drive fusion substances to burst and generate welding defects such as bubbles and pits.

⑤ press fitting

The press-fitting equipment is selected as a 10T oil press, and a press-fitting tool for the oil seal cover 5 is reasonably designed, as shown in figure 3: the second pressure head 22 is fixed on the pressure head 23 of the original factory by using the hexagon socket head cap screw 25, the nut 26 and the gasket 24, the cushion block 20 is placed on the working platform of the oil press, the centering is carried out and the fixing is carried out by using the pressure plate, the positioning device 21 is placed in the central groove of the cushion block 20, and the inner hole of the side gear is placed and fixed along the positioning shaft 27 of the positioning device 21. The positioner 21 is in an inverted T shape, the positioner 21 comprises a bottom and a positioning shaft 27 fixed in the center of the bottom, and the gear tooth end of the shaft hole 3 faces upwards; the press-fitting inner hole 4 is also positioned at the upper end of the shaft hole 3; spline tooth 7 path and location axle 27 clearance fit in the shaft hole 3, location axle 27 can just pass through spline tooth 7 path, fix gear body 1.

The chamfered surface of the oil seal cover 5 faces downwards and is horizontally placed at the hole inlet of the press-fitting inner hole 4 of the side gear. In operation, the second ram 22 slides downward and the end face of the second ram 22 contacts the oil cap 5, pressing the oil cap 5 into the side gear. The end surface of the positioning shaft 27 of the positioner 21 is just flush with the bottom of the press-fitting inner hole 4 of the side gear, so that the consistency of the positions of all the oil seal covers 5 in the workpiece in the press-fitting process is ensured. The arrangement of the cushion block 20 and the second pressure head 22 can reduce deformation and abrasion of the original factory pressure head 23 and the working platform, and is convenient for long-term use of equipment.

Two rubber rings 15 can be selectively installed in the press mounting of the two annular grooves 8, and the rubber rings 15 can position and fix the positioning shaft 27 in the press mounting process, so that the diameter of the positioning shaft 27 can be smaller, the interference with a spline is avoided, and the spline cannot be deformed and damaged even if the press mounting is unqualified; meanwhile, the positioning device can be stably connected with the half axle gear, and a better positioning effect is achieved.

After press mounting is finished, a steel ruler is used for leaning against the end face, the gradient of the oil seal cover 5 on the press mounting end face is observed, and the oil seal cover needs to be pulled out and pressed again when the workpiece is obviously inclined. And detecting whether the pressed workpiece is air-leaked by using air-tightness detection equipment, and removing the oil seal cover 5 after air leakage and pressing again.

2. Welding of

During laser welding, the laser welding device shown in the figures 4-7 is utilized, wherein a special clamp clamps one end of a gear shaft of the half-gear and flatly places the gear shaft on a workbench, a laser head 61 of a laser welding machine is utilized to adjust a laser focusing point to a joint gap between the oil seal cover 5 and the gear body 1, so that a focusing effect is achieved, if defocusing occurs, the influence on the welding depth is great, and the more defocusing, the shallower welding depth is. During the laser welding, the laser beam is output and simultaneously the inert gas is sprayed to the welding seam 70; and an annular inert gas injection zone is provided around the weld 70 to cover the weld 70.

The preheating power is set to be 0.8kW and the welding power is set to be 1.85kW, 11 circles of light spots are arranged along a welding line 70 of an oil seal cover 5, the surface temperature of the gear and the oil seal cover is preheated to 80-100 ℃, 2 circles of light spots are arranged with the welding power, and finally 1 circle of light spots is arranged with the preheating power of 1.0kW, so that the surface appearance during welding is improved. Setting laser edgeThe linear velocity of the weld joint 70 is 15-25mm/s, for example, the diameter of the oil seal cover 5 of the invention is

The time per turn was set to 5.5 seconds. Argon gas is blown out from the gas nozzle 373 from the beginning of preheating during welding, the argon gas is inert gas, gear oxidation during welding is prevented, and the welding appearance of a welded product is good. The argon line is about 3-6cm from the gear surface. This distance is best for the discharge of impurities and the welding of the gears. Argon was turned on during preheating until welding was complete.

The laser welding device is specifically shown in fig. 4-7, and comprises a special fixture 30 and a laser head 61, wherein the laser head 61 is provided by a special laser welding machine or the whole welding is an integrated laser head 61, and emits welding laser. The special fixture 30 includes a supporting base plate 31, a first cylinder 32 is fixed on the supporting base plate 31 through a cylinder fixing base on the right side edge of the supporting base plate 31, and a connecting block 321 connects a push rod of the first cylinder 32 with a sliding track 34 and an L-shaped connecting plate 35. The first cylinder 32 is, for example, an alder cylinder. L type connecting plate 35 is connected with air cock fixed plate 36, and air cock fixed plate 36 welds with air cock ring 37, and air cock ring 37 includes upper air cock ring 371, and upper air cock ring 371 is fixed with lower air cock ring 372 that is located its below, and upper air cock ring 371 and lower air cock ring 372 are coaxial to be arranged. Air pipes 374 are fixed around the two parts, and the air pipes 374 are connected with air nozzles 373 facing the workpiece. Tee 46 is connected to air tube 374 on lower nozzle ring 372. The tee 46 is vented by blowing argon or similar inert gas through the gas nozzle 373 against the workpiece to prevent oxidation during welding of the workpiece.

The structure of the air nozzle ring 37 formed by fixedly connecting the lower air nozzle ring 372 and the upper air nozzle ring 371 can ensure that the lower air nozzle ring 372 which is often close to a high-temperature workpiece is replaced after the service life is reached, and the size, the precision and the air injection effect of the whole air nozzle ring 37 are ensured. The gas pipe 374 surrounds the sidewall of the nozzle ring 37, and the connected gas nozzles 373 are uniformly arranged along the nozzle ring 37, and the gas nozzles 373 have a certain opening angle, so that the gas sprayed from several gas nozzles 373 can cover the whole weld joint 70. The air nozzle 373 is typically spaced from the weld 70 by a distance of 3-6 cm. The air inlet pipe for air injection is fixed on the outer shell of the sliding track 34 to prevent the air inlet pipe from being burnt by contacting with the surface of the workpiece which is just welded. The injection zones of the plurality of gas nozzles 373 on the lower nozzle ring 372 cover the annular inert gas injection zone that constitutes the surrounding weld 70.

The proximity switch 38 is installed in the hole of the fixed base 39, and the proximity switch 38 and the fixed base 39 are fixedly connected by a mounting plate 381 for detecting whether a workpiece exists in the fixture body 40. A clamp body 40 is respectively fixed on the fixed base 39 and the movable base 41, the clamp body 40 is made of copper or similar materials which do not damage the workpiece, and the two clamp bodies 40 are combined to form a clamping state which is matched with the appearance of the workpiece. The fixed base 39 is fixed to the support base plate 31, and the moving base 41 movable toward the fixed base 39 is slidably engaged with the support base plate 31. The fixed base 39 is connected to the cylinder fixing plate 45 by two connecting rods 44, and the connecting rods 44 pass through holes on the movable base 41, so that the movable base 41 can slide along the connecting rods 44 in the horizontal direction and is aligned with the fixed base 39. The rear part of the movable base 41 is fixedly connected with a connecting plate 42, and the middle part of the connecting plate 42 is connected with a push rod of a second air cylinder 43. Elastic compression rods can be arranged between the fixed base 39 and the cylinder fixing plate 45 and on two sides of the push rod. The second cylinder 43 is a thin cylinder, so that the volume of the device is reduced; the cylinder is provided with a cylinder pull rod extending sensor and a cylinder pull rod retracting sensor respectively, so that the working state of the cylinder can be conveniently detected. And the second cylinder 43 is fixed by a cylinder fixing plate 45 fixed on the edge of the support base plate 31. The second cylinder 43 can move the movable base 41 by the extension and contraction of the push rod. The elastically compressible rod is, for example, a sleeve with a spring inside, and has an overall length capable of elastically expanding and contracting within a certain range under an external force. Through the arrangement of the connecting plate 42 and the elastic compression rod, the second cylinder 43 can push the movable base 41 more stably, and uneven stress caused by point contact pushing of the cylinder push rod and the movable base 41 is avoided.

The laser head 61 faces downward vertically and is provided with a traveling mechanism for horizontally moving the laser head 61 along a set track. Laser head 61 is the nib form, is provided with the laser beam passageway along the axle center, and laser head 61 upper portion is provided with focusing lens 62 through lens support 65, sets up laser entry 63 directly over focusing lens 62, is provided with inlet port 64 on the laser head 61 lateral wall of focusing lens 62 downside, and the inert gas is passed through the hose connection in the inlet port 64 outer end. Thus, the laser from the laser welding machine is converged into a laser beam by the focusing lens 62 to generate a high temperature required for welding, and the inert gas enters through the gas inlet 64 and is then ejected out of the lower end opening of the laser head 61 in the laser irradiation direction. The generated heat of the laser can be carried away to keep the focusing lens 62 clean and low temperature. Meanwhile, inert gas is blown to the welding line at any time to play a role in protecting the high-temperature welding line from being oxidized.

The reason that the plurality of gas nozzles 373 and the larger coverage area of the ejected inert gas are needed to increase the inert gas by arranging the gas nozzle ring 37 under the condition that the laser head 61 has the inert gas is that the laser head 61 can avoid the phenomenon that the negative pressure generated by the gas flow sucks the air when the inert gas is ejected by the laser head 61, so that the air and the inert gas mixed gas is actually ejected onto the welding line, and the welding line is still oxidized. And the temperature of the place where the laser head 61 passes is still high, it is also necessary that the nozzle ring 37 and the gas nozzle 373 continue to be protected with inert gas.

When the welding device is used, after a differential gear workpiece is placed between the two clamp bodies 40 between the fixed base 39 and the movable base 41, the proximity switch 38 senses that the workpiece is in place and feeds back signals to the system, the system sends signals to work through the first air cylinder 32, and the first air cylinder 32 transversely moves the lower air nozzle ring 372 and the upper air nozzle ring 371 to the position right above the workpiece under the combined action of the connecting block 321, the sliding crawler 34 and the L-shaped connecting plate 35. The in-place sensor on the first air cylinder 32 senses and receives signals and feeds back workpiece in-place signals to the system, the system sends signals to the second air cylinder 43, and the second air cylinder 43 works to push the movable base 41 to move through the push rod so as to clamp the workpiece. After the workpiece is clamped, the push rod of the second air cylinder 43 extends out of the sensor, when the push rod is sensed to push the clamp body 40 to be clamped in place, a signal is fed back to the system to start welding, and meanwhile, the tee joint 46 connected with the air pipe 374 on the lower nozzle ring 372 is ventilated to start blowing inert gas to protect a welding seam.

After the welding of the workpiece is completed, the system sends a signal to the second air cylinder 43 to start working, and the push rod of the second air cylinder 43 pulls the moving base 41 to move so as to release the workpiece. After the workpiece is loosened, the push rod of the second air cylinder 43 is pulled back to the proper position, and the sensor senses that the workpiece is loosened to the proper position and then feeds back a signal of loosening to the proper position to the system. The system sends a working signal to the first air cylinder 32 after receiving the signal, the first air cylinder 32 starts to work, the air nozzle ring 37 is transversely moved to the initial position through the combined action of the connecting block 321, the sliding crawler 34 and the L-shaped connecting plate 35, the workpiece is taken down, and the welding is completed.

Claims

1. A shaft hole sealing structure of a differential half shaft gear comprises a gear body (1) and a plurality of gear teeth (2) uniformly distributed at one end of the gear body (1), wherein a shaft hole (3) is formed along the axis of the gear body (1); the method is characterized in that: shaft hole (3) through gear body (1) shaft hole (3) are located teeth of a cogwheel (2) one end and are equipped with coaxial pressure equipment hole (4), and pressure equipment hole (4) aperture is greater than shaft hole (3) aperture, be equipped with oil seal lid (5) in pressure equipment hole (4), both constitute the tight fit, oil seal lid (5) outward flange and pressure equipment hole (4) pore wall constitute the laser welding and are connected.

2. The shaft hole sealing structure of a differential side gear according to claim 1, characterized in that: the shaft hole (3) is internally provided with a large-diameter part (6), spline teeth (7) and a stepped hole part from the press-fitting inner hole (4) to the inside in sequence, and the diameter of the stepped hole part is sequentially increased towards the direction far away from the press-fitting inner hole (4); and annular grooves (8) are respectively arranged at the spline teeth (7) and the end parts of the stepped hole parts, which are closest to the stepped hole parts.

3. The shaft hole sealing structure of a differential side gear according to claim 1, characterized in that: the distance between the root of the gear tooth (2) and the hole wall of the press-fitting inner hole (4) is 5-8 mm.

4. The shaft hole sealing structure of a differential side gear according to claim 1, characterized in that: the tooth grooves (9) between the roots of the adjacent gear teeth (2) are ship-shaped grooves with two high ends and a low middle part.

5. The shaft hole sealing structure of a differential side gear according to any one of claims 1 to 4, wherein: the edge of the lower end face of the oil seal cover (5) and the edge of the upper end of the press-fitting inner hole (4) are provided with a radius or a chamfer.

6. A process for manufacturing a shaft hole seal structure of a side gear of a differential gear according to any one of claims 1 to 5, comprising the steps of:

1) machining: machining the half axle gear, wherein the machining comprises machining a through shaft hole (3), arranging a press-fitting inner hole (4) at the end of the gear tooth (2) of the shaft hole (3), and then performing surface treatment to obtain a finished half axle gear; selecting a material which is the same as the material of the half axle gear to machine an oil seal cover (5); in the machining, the oil seal cover (5) and the press-fitting inner hole (4) form tight fit for machining;

2) removing the carburized layer: turning off a carburized layer on the inner wall of a press-fitting inner hole (4) of the semi-axis gear;

3) press fitting: after thorough cleaning, the oil seal cover (5) is pressed into the press-fitting inner hole (4);

7. The process of claim 6, wherein: the press fitting is that the cushion block (20) is placed on a hydraulic press working platform, is centered and is fixed by a pressing plate, and then the positioner (21) is placed in a central groove of the cushion block (20);

sleeving a semi-axis gear shaft hole (3) on a positioning shaft (27) of a positioner (21) and fixing, wherein the end of a gear tooth (2) of the shaft hole (3) faces upwards; the side, with the chamfer, of the oil seal cover (5) faces downwards and is horizontally placed at the hole inlet of the press-fitting inner hole (4);

when the hydraulic press works, a pressure head (23) of the hydraulic press slides downwards, the lower end face of the pressure head (23) gradually contacts the oil seal cover (5), and the oil seal cover (5) is pressed into the side gear;

the upper end face of a positioning shaft (27) of the positioner (21) is just flush with the bottom of a press-fitting inner hole (4) of the side gear, so that the consistency of the positions of all oil seal covers (5) in the workpiece in the press-fitting process is ensured.

8. The process of claim 6, wherein: during the laser welding, the laser beam is output and simultaneously the inert gas is sprayed to a welding seam; and an annular inert gas injection area is arranged around the weld seam to cover the weld seam.

9. The process of claim 8, wherein: the special welding jig of gear terminal surface include: during welding, a laser beam is used for firstly walking 11 circles at the welding seam of the press-fitting inner hole (4) and the oil seal cover (5) with 0.8KW power, and the surface temperature of the welding seam is preheated to 80-100 ℃; then, the welding power of 1.85kW is used for 2 turns, and finally the preheating power of 1.0kW is used for 1 turn of surface; setting the linear speed of laser to 15-25 mm/s.

10. The process of claim 9, wherein: the laser welding device comprises a laser head (61), wherein the laser beam output by the laser head (61) is simultaneously accompanied with the ejection of inert gas; the special fixture (30) comprises a supporting bottom plate (31), two separable fixture bodies (40) are arranged on the supporting bottom plate (31), and the two fixture bodies (40) are combined to form clamping with a workpiece; an air nozzle ring (37) is arranged above the clamp body (40), an air pipe (374) is connected to the air nozzle ring (37), an air nozzle (373) is connected to the air pipe (374), and the air blowing area of the air nozzle (373) covers the whole workpiece to be welded.