Differential mechanism and manufacturing method thereof

Abstract

The invention provides a differential mechanism and a manufacturing method thereof. The differential mechanism comprises an input gear, a limiting mechanism and a bevel gear set which are assembled together. The inner circumferential surface of the input gear forms a cylindrical surface, and the limiting mechanism is fixed to the inner circumferential surface and limits two paired mounting grooves. Mounting parts formed at the two ends of a gear shaft of the bevel gear are mounted in the two mounting grooves respectively, and therefore the gear shaft and the input gear can rotate together through the limiting mechanism. In addition, the two bevel gears of the first bevel gear pair are installed on the gear shaft in a spaced mode and can independently rotate around the gear shaft, and each bevel gear of the two bevel gears of the second bevel gear pair is always meshed with the two bevel gears of the first bevel gear pair. Therefore, the inner circumferential surface of the input gear can form a cylindrical surface without a mounting groove, so that the machining difficulty of the input gear is greatly reduced, and the machining cost of the input gear is reduced.

Description

Technical Field

[0001] The present application relates to the field of vehicle differentials, and in particular to a differential and a method for manufacturing the differential. Background Art

[0002] In the prior art, a differential is usually used in a transmission mechanism of a vehicle to transmit torque from a transmission of the vehicle to wheels and enable different wheels to rotate at different speeds when the vehicle turns.

[0003] In a typical differential, it includes an input gear, a housing and a bevel gear set. The input gear can also be called the final drive gear, which is used to receive torque from the transmission. The input gear and the housing surround a mounting space, and the bevel gear set is located in the mounting space. The bevel gear set includes a gear shaft (usually a pin shaft) and two bevel gear pairs assembled together, and the two ends of the gear shaft are installed in the mounting groove formed on the inner circumference of the input gear. One bevel gear pair is installed on the gear shaft, and the other gear pair is always in a tooth meshing state with the bevel gear pair installed on the gear shaft. As a result, the torque received by the input gear can be transmitted sequentially through the input gear, the gear shaft, the above-mentioned one bevel gear pair and the above-mentioned other bevel gear pair.

[0004] However, in the above differential, if Figure 1 As shown, since the inner circumference 10s of the input gear 10 matches the spherical outer circumference of the bevel gear of the first bevel gear pair, the inner circumference 10s of the input gear 10 needs to be formed into a spherical surface. Further, in order to install the gear shaft, two mounting grooves 10c are formed on the inner circumference 10s of the input gear 10, and the two ends of the gear shaft can be inserted and installed in the mounting grooves 10c, so that the gear shaft can rotate with the input gear 10. In this way, the inner circumference 10s of the input gear 10 needs to be processed into a spherical surface while the mounting grooves 10c need to be processed, which results in the inner circumference 10s of the input gear 10 having a complex structure, thereby increasing the difficulty of processing. In addition, step structures 10m are formed on both sides of the inner circumference 10s of the input gear 10 for welding with the housing. However, since the input gear 10 needs to be carburized, the carburized layer of the step structure 10m needs to be removed in order to be welded with the housing, which makes the processing allowance of the inner circumference 10s of the input gear 10 and the surface of the step structure 10m different, thereby increasing the difficulty of processing. Summary of the invention

[0005] This application is made based on the defects of the above-mentioned prior art. One purpose of this application is to provide a new type of differential, which can greatly reduce the processing difficulty of the input gear of the differential, thereby reducing the processing cost of the input gear. Another purpose of this application is to provide a manufacturing method of the above-mentioned differential.

[0006] In order to achieve the above-mentioned purpose, the present application may adopt the following technical solutions.

[0007] The present application provides a differential as follows, comprising:

[0008] An input gear, the inner peripheral surface of which is formed as a cylindrical surface;

[0009] a limiting mechanism, which is fixed to the inner circumferential surface of the input gear and defines two mounting grooves; and

[0010] A bevel gear set, comprising a gear shaft, a first bevel gear pair and a second bevel gear pair, wherein the gear shaft extends along a radial direction of the input gear, and the mounting parts of the gear shaft at both ends are respectively mounted in the two mounting grooves, and the gear shaft and the input gear are relatively fixed in the circumferential direction of the input gear by means of the limiting mechanism, so that the gear shaft can rotate with the input gear, the two bevel gears of the first bevel gear pair are installed on the gear shaft at intervals and can rotate around the gear shaft, and each of the two bevel gears of the second bevel gear pair is always meshed with the two bevel gears of the first bevel gear pair.

[0011] In an optional solution, the limiting mechanism includes a plurality of arc-shaped limiting portions.

[0012] The plurality of arc-shaped limiting portions are arranged at intervals in the circumferential direction, and the mounting groove is defined between adjacent arc-shaped limiting portions.

[0013] Each of the arc-shaped limiting portions extends along the circumferential direction, and the outer circumferential surface of each arc-shaped limiting portion is fixed to the inner circumferential surface of the input gear by welding.

[0014] In another optional solution, the outer circumference of the arc-shaped limiting portion is formed as a cylindrical surface to match the inner circumference of the input gear, and the inner circumference of the arc-shaped limiting portion is formed as a spherical surface to match the outer circumference of the bevel gear of the first bevel gear pair.

[0015] In another optional solution, the limiting mechanism includes an annular limiting portion, which extends continuously along the circumference around the entire circumference, the mounting groove is formed in the annular limiting portion, and the outer circumference of the annular limiting portion is fixed to the inner circumference of the input gear by welding.

[0016] In another optional scheme, the outer circumferential surface of the annular limiting portion extends continuously along the circumferential direction over the entire circumference, and matches the shape of the inner circumferential surface of the input gear, and the inner circumferential surface of the annular limiting portion is formed as a spherical surface to match the shape of the outer circumferential surface of the bevel gear of the first bevel gear pair, wherein the mounting groove is formed in the form of a notch on the inner circumferential surface of the annular limiting portion.

[0017] In another optional solution, the differential further includes a first split portion and a second split portion as a housing,

[0018] The input gear has a first joint surface and a second joint surface, the first joint surface is located on one axial side of the inner circumference of the input gear, and the second joint surface is located on the other axial side of the inner circumference of the input gear, the first split portion is fixed to the first joint surface by welding, and the second split portion is fixed to the second joint surface by welding, so that an installation space is formed by surrounding the input gear, the first split portion and the second split portion, and the bevel gear set is located in the installation space.

[0019] In another optional solution, the limiting mechanism is fixed to the inner circumferential surface of the input gear, and the first split portion and the second split portion are used to axially limit the mounting portion of the gear shaft.

[0020] The present application also provides a method for manufacturing the differential as described above, comprising:

[0021] providing an input gear whose inner peripheral surface is formed as a cylindrical surface;

[0022] Providing a plurality of arc-shaped limiting portions; and

[0023] A gear shaft is provided, and the gear shaft is positioned on the inner side of the input gear along a radial direction of the input gear. When the gear shaft is positioned, the outer circumferential surfaces of the plurality of arc-shaped limiting portions are welded to the inner circumferential surface of the input gear, so that the mounting grooves defined by adjacent arc-shaped limiting portions match the mounting portions of the gear shaft at both ends thereof.

[0024] In an optional solution, the above manufacturing method includes:

[0025] Providing an annular intermediate body extending continuously along the circumference over the entire circumference, dividing the annular intermediate body into a plurality of the arc-shaped limiting portions, wherein one annular intermediate body is divided into N arc-shaped limiting portions, wherein N is an even number and N≥8;

[0026] In the step of welding the outer circumferential surfaces of the plurality of arc-shaped limiting portions to the inner circumferential surface of the input gear, four arc-shaped limiting portions among the N arc-shaped limiting portions are welded to one input gear.

[0027] The present application also provides another method for manufacturing the differential as described above, comprising:

[0028] providing an input gear whose inner peripheral surface is formed as a cylindrical surface;

[0029] Providing an annular intermediate body extending continuously along the circumference over the entire circumference, and processing a mounting groove in the annular intermediate body to form an annular limiting portion;

[0030] providing a gear shaft, and installing the gear shaft into the installation groove; and

[0031] The outer circumferential surface of the annular limiting portion is welded to the inner circumferential surface of the input gear.

[0032] By adopting the above technical solution, the present application provides a differential and a manufacturing method thereof. In the differential, an input gear, a limiting mechanism and a bevel gear set are assembled together. The inner circumferential surface of the input gear is formed as a cylindrical surface, and the limiting mechanism is fixed to the inner circumferential surface and defines two paired mounting grooves. Further, the bevel gear set includes a gear shaft, a first bevel gear pair and a second bevel gear pair assembled together. The gear shaft extends along a radial direction of the input gear, and the mounting portions formed at both ends thereof are respectively mounted in the two mounting grooves, thereby using the limiting mechanism to relatively fix the gear shaft and the input gear in the circumferential direction of the input gear, so that the gear shaft can rotate with the input gear. In addition, the two bevel gears of the first bevel gear pair are installed on the gear shaft at intervals and can rotate independently around the gear shaft, and each of the two bevel gears of the second bevel gear pair is respectively engaged with the two bevel gears of the first bevel gear pair.

[0033] Thus, unlike the differential described in the background art, in the differential of the present application, the installation groove is defined by a limiting mechanism that is independently manufactured and fixedly installed on the inner circumference of the input gear, and the inner circumference of the limiting mechanism can replace the inner circumference of the input gear to cooperate with the outer circumference of the bevel gear. As a result, it is not necessary to machine the installation groove on the inner circumference of the input gear and it is not necessary to machine the inner circumference of the input gear into a spherical surface, so the inner circumference of the input gear can be formed into a cylindrical surface without the installation groove. In this way, the processing difficulty of the input gear is greatly reduced, and the processing cost of the input gear is reduced.

[0034] In a manufacturing method of the above differential, the following steps are included: providing an input gear whose inner circumference is formed as a cylindrical surface; providing a plurality of arc-shaped limit portions; installing the gear shaft to the inner side of the input gear in a manner that its extension direction is along a radial direction of the input gear, and welding the outer circumferences of the plurality of arc-shaped limit portions to the inner circumference of the input gear while maintaining the above state, so that the mounting grooves defined by the adjacent arc-shaped limit portions match the mounting portion formed at the end of the gear shaft.

[0035] In this way, since the arc-shaped limit portion is welded to the input gear when the gear shaft is installed in place, the processing accuracy of the mounting portion of the gear shaft that cooperates with the mounting groove can be reduced compared to the gear shaft of the existing differential, thereby reducing the processing cost of the gear shaft.

[0036] Another manufacturing method of the differential includes the following steps: providing an input gear whose inner circumference is formed as a cylindrical surface; providing an annular intermediate body extending continuously along the entire circumference, and forming an annular stopper by machining a mounting groove in the annular intermediate body; installing the mounting portion of the gear shaft into the mounting groove; and welding the outer circumference of the annular stopper to the inner circumference of the input gear.

[0037] In this way, since the annular stopper portion extends continuously over the entire circumference, it is possible to ensure the strength of the stopper mechanism itself and to improve the engagement strength between the stopper mechanism and the input gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The figure is a three-dimensional schematic diagram showing an input gear of a conventional differential.

[0039] Figure 2A 1 is a schematic cross-sectional view showing a differential according to a first embodiment of the present application, wherein the schematic cross-sectional view is taken along the axial direction of an input gear.

[0040] Figure 2B It shows Figure 2A Another schematic cross-sectional view of the differential in FIG. 1 , wherein the schematic cross-sectional view is taken along a direction perpendicular to the axial direction of the input gear.

[0041] Figure 2C It shows Figure 2A A three-dimensional schematic diagram of the assembly of the input gear and the limiting mechanism of the differential.

[0042] Figure 2D to Figure 2G It is used to illustrate Figure 2A An explanatory diagram of a method for manufacturing a differential in FIG.

[0043] Figure 3A 1 is a perspective schematic diagram showing an assembly of an input gear and a limiting mechanism of a differential according to a second embodiment of the present application.

[0044] FIG. 3B to FIG. 3F It is used to illustrate Figure 3A An explanatory diagram of a method for manufacturing a differential in FIG.

[0045] Description of Reference Numerals

[0046] 10 input gear; 10s inner circumference; 10c mounting groove; 10m step structure;

[0047] 1 input gear; 1s1 inner peripheral surface; 1s2 first joint surface; 1s3 second joint surface;

[0048] 2 limiting mechanism; 2c mounting groove; 21 arc-shaped limiting portion; 22 annular limiting portion;

[0049] 3 bevel gear set; 31 gear shaft; 31p mounting portion; 32a first bevel gear; 32b second bevel gear; 33a third bevel gear; 33b fourth bevel gear;

[0050] 41 first split portion; 411 first tapered portion; 411h first weight-reducing hole; 412 first bearing seat;

[0051] 42 second split portion; 421 second tapered portion; 421h second weight-reducing hole; 422 second bearing seat;

[0052] B annular intermediate body; S installation space; A axial direction; R radial direction; C circumferential direction. DETAILED DESCRIPTION

[0053] The specific embodiments of the present application will be described in detail below in conjunction with the drawings of the specification. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all feasible methods of the present application, nor to limit the scope of the present application.

[0054] In the present application, "drive connection" refers to a connection between two components that can transmit torque, including direct connection and indirect connection.

[0055] In this application, unless otherwise specified, "axial", "radial" and "circumferential" refer to the axial, radial and circumferential directions of the input gear, respectively, and "axial side" refers to the Figure 2A The left side of the axis refers to Figure 2A Further, the inner peripheral surface of the input gear refers to the surface of the input gear located radially innermost and extending along the circumferential direction.

[0056] The differential of the first embodiment of the present application is described below in conjunction with the accompanying drawings.

[0057] (Differential gear and manufacturing method thereof according to the first embodiment of the present application)

[0058] like FIG. 2A to FIG. 2C As shown, the differential according to the first embodiment of the present application includes an input gear 1, a limit mechanism 2, a bevel gear set 3 and a housing (a first split part 41 and a second split part 42) assembled together. Figure 2A As shown, there is a symmetry plane perpendicular to the axial direction A (e.g. Figure 2B The differential as a whole may have a symmetrical structure relative to the symmetry plane. Here, symmetry means that the overall structure layout of the differential is roughly symmetrical, but not necessarily completely accurate symmetry. For example, in this embodiment, the external teeth of the input gear 1 may have an asymmetric shape relative to the symmetry plane, and the input gear 1 may be a helical gear.

[0059] In this embodiment, the input gear 1 can be drivingly coupled to the output gear of the output shaft of the vehicle's transmission, so that the torque from the outside of the differential can be transmitted to the input gear 1. FIG. 2A to FIG. 2C As shown, the input gear 1 has a circular ring shape and is coaxially arranged with the housing and the third bevel gear 33a and the fourth bevel gear 33b of the second bevel gear pair of the bevel gear set 3. In order to improve the strength of the input gear 1, the input gear 1 may be carburized.

[0060] like FIG. 2A to FIG. 2C As shown, the input gear 1 has an inner circumferential surface 1s1, a first joint surface 1s2 and a second joint surface 1s3. The inner circumferential surface 1s1 is formed as a cylindrical surface. The first joint surface 1s2 is located on one axial side of the inner circumferential surface 1s1, and the second joint surface 1s3 is located on the other axial side of the inner circumferential surface 1s1, that is, the inner circumferential surface 1s1 is located between the first joint surface 1s2 and the second joint surface 1s3. The limiting mechanism 2 is fixed to the inner circumferential surface 1s1, the first split portion 41 of the shell is fixed to the first joint surface 1s2, and the second split portion 42 of the shell is fixed to the second joint surface 1s3. The first joint surface 1s2 and the second joint surface 1s3 can be slightly recessed toward the radial outside relative to the inner circumferential surface 1s1 to form a shoulder or a step structure.

[0061] In this embodiment, the limiting mechanism 2 is made of metal and is not subjected to carburizing or other hardening treatments. FIG. 2A to FIG. 2C As shown, the limiting mechanism 2 is fixed to the inner circumferential surface 1s1 and defines two pairs of mounting grooves 2c. The limiting mechanism 2 includes four arc-shaped limiting portions 21, which are arranged at intervals in the circumferential direction C. The four arc-shaped limiting portions 21 can be divided into two pairs. One pair is located at Figure 2B and Figure 2C The arc-shaped limiting portion 21 on the upper middle side includes two adjacent arc-shaped limiting portions 21, and a mounting groove 2c is defined between them. Figure 2B and Figure 2C The arc-shaped limiting portion 21 at the middle and lower side includes two adjacent arc-shaped limiting portions 21, and another mounting groove 2c is defined between them. The two mounting grooves 2c are separated by a central angle of 180 degrees and have the same shape. Figure 2B and Figure 2C As shown, each mounting groove 2c is a U-shaped groove, and the cross section has a square shape corresponding to the mounting portion 31p formed at the end of the gear shaft 31. The circumferential side wall surface of the mounting groove 2c is formed as a plane parallel to each other, and is used to abut against the mounting portion 31p of the gear shaft 31.

[0062] Further, the outer circumference of the arc-shaped limiting portion 21 is formed as a cylindrical surface (a part of the cylindrical surface) to match the shape of the inner circumference 1s1 of the input gear 1, and the outer circumference of each arc-shaped limiting portion 21 is fixed to the inner circumference 1s1 by welding. The axial width of each arc-shaped limiting portion 21 is the same as the axial width of the inner circumference 1s1, and each arc-shaped limiting portion 21 extends a certain length along the circumferential direction C. In addition, the inner circumference of the arc-shaped limiting portion 21 is formed as a spherical surface (a part of the spherical surface) to match the spherical outer circumference of the first bevel gear 32a and the second bevel gear 32b of the first bevel gear pair, thereby avoiding interference with the limiting mechanism 2 during the rotation of the first bevel gear 32a and the second bevel gear 32b.

[0063] In this embodiment, if Figure 2A As shown, the bevel gear set 3 is received and installed in the installation space S formed by the first split part 41 and the second split part 42. The bevel gear set 3 includes a gear shaft 31, a first bevel gear pair (first bevel gear 32a and second bevel gear 32b) and a second bevel gear pair (third bevel gear 33a and fourth bevel gear 33b).

[0064] like Figure 2A and Figure 2B As shown, the gear shaft 31 extends along a radial direction R of the input gear 1 and is transmission-connected with the input gear 1. Specifically, the mounting portions 31p of the gear shaft 31 located at both ends thereof are inserted into the mounting groove 2c defined by the multiple arc-shaped limiting portions 21 of the limiting mechanism 2 in a detachable manner. The first bevel gear 32a and the second bevel gear 32b of the first bevel gear pair are installed on the gear shaft 31 at intervals, so that the first bevel gear 32a and the second bevel gear 32b can rotate together with the gear shaft 31 as a whole, and the first bevel gear 32a and the second bevel gear 32b can also rotate independently around the gear shaft 31. Further, the mounting portions 31p formed at both ends of the gear shaft 31 can be formed with abutment portions that are shaped in conjunction with the two circumferential side walls of the mounting groove 2c and contact each other, and the two circumferential side walls cooperate with the abutment portions to realize the transmission connection between the input gear 1 and the gear shaft 31. In order to make the gear shaft 31 rotate with the input gear 1 but not produce relative rotation with respect to the input gear 1 after the mounting portion 31p is matched with the mounting groove 2c, the cross section of the mounting portion 31p can be formed into a square shape. By using the mounting groove 2c and the mounting portion 31p to match each other, on the one hand, the contact area between the gear shaft 31 and the limiting mechanism 2 is large enough, which is conducive to transmitting a large torque; on the other hand, it can prevent the gear shaft 31 and the limiting mechanism 2 from producing relative rotation.

[0065] Furthermore, if Figure 2A and Figure 2BAs shown, the first bevel gear 32a and the second bevel gear 32b in the first bevel gear pair are mounted on the gear shaft 31 and can rotate around the gear shaft 31. The third bevel gear 33a in the second bevel gear pair is meshed with both the first bevel gear 32a and the second bevel gear 32b, and the fourth bevel gear 33b in the second bevel gear pair is meshed with both the first bevel gear 32a and the second bevel gear 32b. The third bevel gear 33a and the fourth bevel gear 33b are both formed with internal splines, for example, for mating with external splines of a half shaft of a vehicle, so that the differential can output torque to the half shaft via the bevel gear set 3.

[0066] In this embodiment, the housing is a rotating body having a central axis, and the cross-sectional shape of the rotating body at any axial position is annular, and the housing as a whole can rotate around the central axis. Figure 2A and Figure 2B As shown, the housing has a first split portion 41 and a second split portion 42 of the same structure, the first split portion 41 and the second split portion 42 are coaxially arranged with the input gear 1 and symmetrically arranged relative to the above-mentioned symmetry plane, and the first split portion 41 and the second split portion 42 are installed together with the input gear 1 by welding. Specifically, the first split portion 41 is welded and fixed to the first joint surface 1s2, and the second split portion 42 is welded and fixed to the second joint surface 1s3, so that the input gear 1, the first split portion 41 and the second split portion 42 are surrounded to form an installation space S, and the bevel gear set 3 is located in the installation space S.

[0067] like Figure 2A and Figure 2BAs shown, the first split portion 41 includes a first tapered portion 411 and a first bearing seat 412 formed as one body. The large diameter end of the first tapered portion 411 is welded and fixed to the first joint surface 1s2, and the small diameter end of the first tapered portion 411 is connected to the first bearing seat 412. The second split portion 42 includes a second tapered portion 421 and a second bearing seat 422 formed as one body. The large diameter end of the second tapered portion 421 is welded and fixed to the second joint surface 1s3, and the small diameter end of the second tapered portion 421 is connected to the second bearing seat 422. In addition, in order to reduce the weight of the shell, the first tapered portion 411 is formed with a plurality of first weight-reducing holes 411h distributed at intervals in the circumferential direction C, and the second tapered portion 421 is formed with a plurality of second weight-reducing holes 421h distributed at intervals in the circumferential direction C. Since the first split part 41 and the second split part 42 have the same structure, the first split part 41 and the second split part 42 can be formed by precision blanking using the same set of precision blanking equipment, and it is not necessary to perform additional precision processing on the first split part 41 and the second split part 42 to obtain a housing with sufficiently high precision and enable the housing to have dynamic balance during the operation of the differential. Moreover, since the limiting mechanism 2 is fixed to the inner circumferential surface 1s1 of the input gear 1, the first split part 41 and the second split part 42 can axially limit the mounting portion 31p of the gear shaft 31 installed in the mounting groove 2c defined by the limiting mechanism 2.

[0068] The following describes a method for manufacturing a differential according to a first embodiment of the present application. Specifically, Figure 2D to Figure 2G As shown, the manufacturing method includes the following steps.

[0069] like Figure 2D As shown, an input gear 1 is provided, the inner peripheral surface 1s1 of the input gear 1 is formed into a cylindrical surface, and a first joint surface 1s2 and a second joint surface 1s3 are processed on both axial sides of the inner peripheral surface 1s1.

[0070] like Figure 2E As shown, an annular intermediate body B is provided which extends continuously along the circumferential direction C over the entire circumference. Figure 2F As shown, the annular intermediate body B is divided into a plurality of arc-shaped limiting portions 21. In the step of dividing the annular intermediate body B into a plurality of arc-shaped limiting portions 21, one annular intermediate body B can be divided into N arc-shaped limiting portions 21, where N ≥ 8. In this embodiment, one annular intermediate body B is evenly divided into eight arc-shaped limiting portions 21. Of course, the formation method of the arc-shaped limiting portion 21 is not limited to this, and an independently manufactured arc-shaped limiting portion 21 can be provided instead of dividing the arc-shaped limiting portion 21 from the annular intermediate body B.

[0071] Provide a bevel gear set 3. Figure 2GAs shown, the gear shaft 31 on which the first bevel gear 32a and the second bevel gear 32b have been installed is installed to the inner side of the input gear 1 in a manner that its extension direction is along a radial direction R of the input gear 1. While maintaining this state, the outer peripheral surfaces of the plurality of arc-shaped limit portions 21 are welded to the inner peripheral surface 1s1 of the input gear 1, so that the mounting grooves 2c defined by the adjacent arc-shaped limit portions 21 match the mounting portion 31p formed at the end of the gear shaft 31. In the step of welding the outer peripheral surfaces of the plurality of arc-shaped limit portions 21 to the inner peripheral surface 1s1 of the input gear 1, four of the eight arc-shaped limit portions 21 can be welded to one input gear 1. In this way, the manufacturing requirements of two differentials can be met by one annular intermediate body B, thereby saving installation costs. It can be understood that, while meeting the strength requirements, the more arc-shaped limit portions 21 are divided into one annular intermediate body B, the more manufacturing requirements of differentials can be met.

[0072] After that, the first split part 41 and the second split part 42 are provided. The third bevel gear 33a and the fourth bevel gear 33b are meshed with the first bevel gear 32a and the second bevel gear 32b, and then the first split part 41 and the second split part 42 are respectively welded to the first joint surface 1s2 and the second joint surface 1s3 of the input gear 1. Thus, the assembled differential is obtained.

[0073] The differential of the second embodiment of the present application is described below in conjunction with the accompanying drawings.

[0074] (Differential gear and manufacturing method thereof according to the second embodiment of the present application)

[0075] The structure of the differential according to the second embodiment of the present application is substantially the same as the structure of the differential according to the first embodiment of the present application, and the differences between the two are mainly described below.

[0076] In this embodiment, if Figure 3A As shown, the limiting mechanism 2 includes an annular limiting portion 22, which extends continuously along the circumferential direction C over the entire circumference. Two mounting grooves 2c are formed in the annular limiting portion 22, and the outer circumferential surface of the annular limiting portion 22 is fixed to the inner circumferential surface 1s1 by welding. Here, the mounting groove 2c may not penetrate the annular limiting portion 22 in the radial direction R, so that the annular limiting portion 22 will not be cut off by the mounting groove 2c. Further, the outer circumferential surface of the annular limiting portion 22 is formed as a cylindrical surface to match the shape of the inner circumferential surface 1s1 of the input gear 1, and the inner circumferential surface of the annular limiting portion 22 is formed as a spherical surface (a part of the spherical surface) to match the outer circumferential surface shape of the first bevel gear 32a and the second bevel gear 32b of the first bevel gear pair. Since the annular limiting portion 22 extends continuously along the circumferential direction C over the entire circumference, the annular limiting portion 22 itself has greater strength, and can also improve the engagement strength with the input gear 1.

[0077] The following describes a method for manufacturing a differential according to a second embodiment of the present application. Specifically, FIG. 3B to FIG. 3F As shown, the manufacturing method includes the following steps.

[0078] like Figure 3B As shown, an input gear 1 is provided, the inner peripheral surface 1s1 of the input gear 1 is formed into a cylindrical surface, and a first joint surface 1s2 and a second joint surface 1s3 are processed on both axial sides of the inner peripheral surface 1s1.

[0079] like Figure 3C and Figure 3D As shown, an annular intermediate body B is provided which continuously extends along the circumferential direction C over the entire circumference, and a mounting groove 2 c is processed in the annular intermediate body B to form an annular limiting portion 22 .

[0080] Provide a bevel gear set 3. Figure 3E As shown, the gear shaft 31 on which the first bevel gear 32a and the second bevel gear 32b have been mounted is mounted to the mounting groove 2c.

[0081] like Figure 3F As shown, the outer peripheral surface of the annular limiting portion 22 is welded to the inner peripheral surface 1s1 of the input gear 1.

[0082] Here, the annular stopper 22 can be interference fit with the input gear 1 to a certain extent. Before the annular stopper 22 is installed on the input gear 1, the gear shaft 31 can be easily installed on the installation groove 2c. After the annular stopper 22 is installed on the input gear 1, the annular stopper 22 can be slightly compressed, so that the two ends of the gear shaft 31 can be pressed in the installation groove 2c, so that the position of the gear shaft 31 is stable, the operation of the differential is stable, and the noise is small.

[0083] Of course, the present application is not limited thereto. In other possible ways, after the annular limiting portion 22 is welded to the input gear 1 , the gear shaft 31 on which the first bevel gear 32 a and the second bevel gear 32 b are mounted can be mounted to the mounting groove 2 c.

[0084] After that, the first split part 41 and the second split part 42 are provided. The third bevel gear 33a and the fourth bevel gear 33b are meshed with the first bevel gear 32a and the second bevel gear 32b, and then the first split part 41 and the second split part 42 are respectively welded to the first joint surface 1s2 and the second joint surface 1s3 of the input gear 1. Thus, the assembled differential is obtained.

[0085] The specific technical solution of the present application is described in detail above, but the present application is not limited to the above technical solution, and supplementary explanation is given below.

[0086] i. The split housing has a relatively simple structure and can be manufactured not only by fine blanking but also by precision forging, thereby improving the processing accuracy of the housing and the strength of the components. Since the first split portion 41 and the second split portion 42 have the same structure and are symmetrically arranged, the housing composed of the first split portion 41 and the second split portion 42 can achieve dynamic balance during the operation of the transmission even without additional processing.

[0087] ii. It can be understood that in the differential of the present application, after the input gear 1 is carburized, the carburized layers on the inner peripheral surface 1s1, the first joint surface 1s2 and the second joint surface 1s3 can be removed by the same allowable amount, thereby further simplifying the processing difficulty of the input gear 1.

[0088] iii. In the differential of the present application, the inner peripheral surface 1s1 of the input gear 1 does not have a complex structure, which not only reduces the difficulty of processing the input gear 1, but also simplifies the use of the matching processing tools, and reduces the cost of the entire processing process by more than 20%. Furthermore, using the processing method of the first embodiment, the processing accuracy of the gear shaft 31 (end) can also be reduced, thereby reducing the processing cost. In addition, the technical solution of the present application also improves the utilization rate of welding equipment.

[0089] iv. The differential of the present application may be integrated into a transmission of a vehicle power system, and the transmission may include the differential described in the above specific embodiments. The power source of the vehicle may transmit torque to the wheels via the differential.

Claims

1. A differential, characterized in that: include: An input gear (1) whose inner peripheral surface (1s1) is formed as a cylindrical surface; A limiting mechanism (2), which is fixed to the inner circumferential surface (1s1) of the input gear (1) and defines two mounting grooves (2c); as well as A bevel gear set (3) comprises a gear shaft (31), a first bevel gear pair and a second bevel gear pair, wherein the gear shaft (31) extends along a radial direction (R) of the input gear (1), mounting portions (31p) located at both ends of the gear shaft (31) are respectively mounted in the two mounting grooves (2c), the gear shaft (31) and the input gear (1) are relatively fixed in the circumferential direction (C) of the input gear (1) by means of the limiting mechanism (2), so that the gear shaft (31) can rotate together with the input gear (1), the two bevel gears (32a, 32b) of the first bevel gear pair are installed on the gear shaft (31) at intervals and can rotate around the gear shaft (31), and each of the two bevel gears (33a, 33b) of the second bevel gear pair is always in tooth mesh with the two bevel gears (32a, 32b) of the first bevel gear pair.

2. The differential according to claim 1, characterized in that: The limiting mechanism (2) comprises a plurality of arc-shaped limiting portions (21). The plurality of arc-shaped limiting portions (21) are arranged at intervals in the circumferential direction (C), and the mounting groove (2c) is defined between adjacent arc-shaped limiting portions (21). Each arc-shaped limiting portion (21) extends along the circumferential direction (C), and the outer circumferential surface of each arc-shaped limiting portion (21) is fixed to the inner circumferential surface (1s1) of the input gear (1) by welding.

3. The differential according to claim 2, characterized in that: The outer circumference of the arc-shaped limiting portion (21) is formed as a cylindrical surface to match the shape of the inner circumference (1s1) of the input gear (1), and the inner circumference of the arc-shaped limiting portion (21) is formed as a spherical surface to match the shape of the outer circumference of the bevel gears (33a, 33b) of the first bevel gear pair.

4. The differential according to claim 1, characterized in that: The limiting mechanism (2) comprises an annular limiting portion (22), the annular limiting portion (22) continuously extending along the circumferential direction (C) over the entire circumference, the mounting groove (2c) being formed in the annular limiting portion (22), and the outer circumferential surface of the annular limiting portion (22) being fixed to the inner circumferential surface (1s1) of the input gear (1) by welding.

5. The differential according to claim 4, characterized in that: The outer circumferential surface of the annular limiting portion (22) extends continuously along the circumferential direction over the entire circumference and matches the shape of the inner circumferential surface (1s1) of the input gear (1). The inner circumferential surface of the annular limiting portion (22) is formed as a spherical surface to match the shape of the outer circumferential surfaces of the bevel gears (33a, 33b) of the first bevel gear pair, wherein the mounting groove (2c) is formed in the form of a notch on the inner circumferential surface of the annular limiting portion (22).

6. The differential according to any one of claims 1 to 5, characterized in that: The differential also includes a first split part (41) and a second split part (42) as a housing. The input gear (1) has a first joint surface (1s2) and a second joint surface (1s3); the first joint surface (1s2) is located on one axial side of the inner circumferential surface (1s1) of the input gear (1); the second joint surface (1s3) is located on the other axial side of the inner circumferential surface (1s1) of the input gear (1); the first split portion (41) is fixed to the first joint surface (1s2) by welding; the second split portion (42) is fixed to the second joint surface (1s3) by welding, so that an installation space (S) is formed by the input gear (1), the first split portion (41) and the second split portion (42); the bevel gear set (3) is located in the installation space (S).

7. The differential according to claim 6, characterized in that: The limiting mechanism (2) is fixed to the inner circumferential surface (1s1) of the input gear (1), and the first split portion (41) and the second split portion (42) are used to axially limit the mounting portion (31p) of the gear shaft (31).

8. A method for manufacturing a differential according to claim 2 or 3, characterized in that: include: Providing an input gear (1) whose inner peripheral surface (1s1) is formed as a cylindrical surface; Providing a plurality of arc-shaped limiting portions (21); as well as A gear shaft (31) is provided, and the gear shaft (31) is positioned on the inner side of the input gear (1) along a radial direction (R) of the input gear (1). When the gear shaft (31) is positioned, the outer peripheral surfaces of the plurality of arc-shaped limiting portions (21) are welded to the inner peripheral surface (1s1) of the input gear (1), so that the mounting grooves (2c) defined by adjacent arc-shaped limiting portions (21) match the mounting portions (31p) of the gear shaft (31) located at both ends thereof.

9. A method for manufacturing a differential according to claim 4 or 5, characterized in that: include: Providing an input gear (1) whose inner peripheral surface (1s1) is formed as a cylindrical surface; Providing an annular intermediate body (B) extending continuously along the circumferential direction (C) over the entire circumference, and processing a mounting groove (2c) in the annular intermediate body (B) to form an annular limiting portion (22); Providing a gear shaft (31), and installing the gear shaft (31) into the installation groove (2c); and The outer peripheral surface of the annular limiting portion (22) is welded to the inner peripheral surface (1s1) of the input gear (1).

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