Coaxial differential mechanism with three planetary gears

Abstract

The utility model relates to the technical field of differential mechanisms, in particular to a coaxial differential mechanism with three planetary gears. The differential mechanism comprises a differential mechanism shell and a differential gear assembly arranged in the differential mechanism shell, the differential gear assembly comprises three planetary gears distributed on the same circumference, the included angle between every two adjacent planetary gears is 120 degrees, and the three planetary gears are rotatably connected to a planetary gear supporting structure. A first half axle gear and a second half axle gear are arranged on the front portions and the rear portions of the three planetary gears respectively, each of the three planetary gears is connected with the first half axle gear and the second half axle gear in a meshed mode, and the first half axle gear and the second half axle gear can rotate around the rotation axis. The structure that the three planetary gears are distributed at the included angle of 120 degrees and the structure that the thicknesses of the two ends of the planetary gear shaft are different are adopted, the axial space and the radial space in the differential mechanism can be effectively compressed, and the requirement of a small-size gear set on the internal space is met.

Description

TECHNICAL FIELD

[0001] The utility model relates to differential mechanism technical field especially a coaxial differential mechanism of three planetary gears. BACKGROUND

[0002] Differential mechanisms are usually used in vehicles in order to distribute drive torque to two output shafts. By means of a compensation gear, the differential mechanism allows the two output shafts to be able to rotate relative to one another in order to be able to compensate for different angular velocities in the manner described above when the vehicle is driving around a curve, for example.

[0003] Most of the automobile reduction boxes in the current market are arranged on different shafts, that is, in the case of realizing multi-gear reduction, the centers of the input shaft gear, the intermediate shaft gear and the output shaft differential mechanism assembly are not on the same axis, the radial and axial dimensions of the reduction box are large, which is not conducive to the optimization of the vehicle space layout. And the size of the input shaft gear, the intermediate shaft gear and the output shaft differential mechanism assembly under the arrangement of different shafts is large, and the weight is relatively heavy, which is not conducive to the lightweight of the whole vehicle. SUMMARY

[0004] The present application aims at the shortcomings of the above-mentioned existing production technology, and provides a coaxial differential mechanism of three planetary gears, which adopts the mode of staggered arrangement of planetary disc gears and planetary gears, greatly reduces the axial space and radial space of the differential mechanism under the condition that the power input and output of the whole vehicle are on the same axis, and reduces the weight. At the same time, the structure that three planetary gears are distributed at an angle of 120° and the structure that the thicknesses of the two ends of the planetary gear shaft are different can effectively compress the axial and radial spaces in the differential mechanism, and meet the requirements of small size gears on the internal space.

[0005] The technical scheme adopted by the utility model is as follows:

[0006] A coaxial differential mechanism of three planetary gears, comprising a differential mechanism shell and a differential gear assembly arranged in the differential mechanism shell, the differential gear assembly comprising three planetary gears distributed on the same circumference, the included angle between two adjacent planetary gears being 120°, the three planetary gears being rotatably connected to a planetary gear support structure, first and second half shaft gears being arranged at the front and back of the three planetary gears respectively, each of the three planetary gears being meshingly connected with the first and second half shaft gears, the first and second half shaft gears being able to rotate around an axis of rotation.

[0007] Further, the differential mechanism shell comprises a shell and an end cover, the shell having a mounting opening on one side, the end cover being arranged on the side of the mounting opening, the end cover being connected to the end face of the mounting opening side of the shell, and the end cover being able to seal and close the mounting opening of the shell.

[0008] Further, the planetary gear support structure comprises three planetary gear shafts, each of which is sleeved with a rotatable planetary gear, a support ring is arranged at the central position of the three planetary gear shafts, the support ring is provided with ring body support holes on the end face facing the three planetary gear shafts, three radially through shell support holes are arranged on the shell in the circumferential direction, one end of each of the three planetary gear shafts extends into the three ring body support holes of the support ring, and the other end of each of the three planetary gear shafts extends into the three shell support holes of the shell.

[0009] Further, the other end of each of the three planetary gear shafts is provided with a radially through pin hole, a gear pin is arranged in the pin hole, the two ends of the gear pin extend into the shell pin holes arranged on the shell, a planetary gear gasket is sleeved on the planetary gear shaft, and the planetary gear gasket is located between the planetary gear and the inner wall of the differential housing.

[0010] Further, the diameter of the planetary gear shaft decreases from one end to the other end, and the diameter of the end of the planetary gear shaft connected to the ring body support hole is smaller than the diameter of the end of the planetary gear shaft connected to the shell support hole.

[0011] Further, a protruding first gear shaft part is arranged at the central position of the side end face of the first half shaft gear away from the second half shaft gear, a first half shaft gear gasket is sleeved on the first gear shaft part, and the first half shaft gear gasket is located between the first half shaft gear and the inner wall of the shell, a protruding second gear shaft part is arranged at the central position of the side end face of the second half shaft gear away from the first half shaft gear, a second half shaft gear gasket is sleeved on the second gear shaft part, and the second half shaft gear gasket is located between the second half shaft gear and the inner wall of the end cover.

[0012] Further, a front and rear through half shaft gear shaft hole is arranged at the central position of the second half shaft gear, a sealing plug is arranged on the end of the first half shaft gear facing the half shaft gear shaft hole, the sealing plug and the inner wall of the half shaft gear shaft hole are in interference fit, a circular arc structure stop end face is arranged in the half shaft gear shaft hole, the cross-sectional size of the small diameter end of the stop end face is smaller than the cross-sectional size of the sealing plug, and the stop end face can limit the axial position of the sealing plug.

[0013] Further, the sealing plug comprises a skeleton part and an elastic sealing part, a through hole is arranged at the central position of the skeleton part, a T-shaped buckle structure is arranged at the central position of the elastic sealing part, the buckle structure passes through the through hole of the skeleton part and is clamped on the skeleton part, the elastic sealing part is tightly attached to the front end face of the skeleton part, a protruding sealing ring is arranged on the outer circumference of the elastic sealing part, and the sealing ring and the inner wall of the half shaft gear shaft hole are in interference fit.

[0014] Further, three planetary disc gear installation cavities are arranged on the outer circumference of the shell, each of which can be provided with a planetary disc gear, the three planetary disc gears are distributed at an angle of 120° and are staggered with the three planetary gears in the circumferential direction.

[0015] Further, a lubricating mounting interface is arranged on the outer circumference of the shell, and an oil inlet window is arranged on the outer circumference of the shell.

[0016] The beneficial effects of the utility model are as follows:

[0017] The utility model discloses three planetary gears are arranged at 120 degree angle and the structure that the thickness of planetary gear axle is different at two ends, can effectively compress the axial and radial space in differential mechanism, satisfy the requirement of small size specification gear group on internal space, the utility model discloses the setting of sealing plug cover can guarantee that differential mechanism has good self -sealing function, the setting of stop end surface can limit the axial position of sealing plug cover, avoid sealing plug cover from the half shaft gear axle hole and come off, the setting of sealing ring can effectively improve sealing performance, the second gear axle part surface of the second half shaft gear of the utility model adopts split type processing and secondary grinding process, effectively guarantee the different cooperation accuracy requirement of second gear axle part and shell, reduction gearbox sealing ring, and smaller high low difference, guarantee the strength of second gear axle part, the utility model discloses the installation structure of planetary disc gear of reduction gearbox on shell, through the mode of misplacement arrangement of planetary disc gear and planetary gear, satisfy the condition that the power input and output of whole car are in the same axle center, greatly reduce axial space and radial space, save weight, the utility model discloses the oil inlet window on shell is reserved, and the active lubrication is provided auxiliary. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the perspective view of the utility model.

[0019] Figure 2 It is the half cutaway view of the utility model.

[0020] Figure 3 It is the differential gear assembly structure diagram of the utility model.

[0021] Figure 4 It is the planetary gear arrangement structure diagram of the utility model.

[0022] Figure 5 It is the second half shaft gear half cutaway structure diagram of the utility model.

[0023] Figure 6 It is the sealing end cap structure diagram of the utility model.

[0024] Wherein: 1, the shell; 2, the first half shaft gear gasket;3, the first half shaft gear;4, planetary gear;5, planetary gear gasket;6, planetary gear shaft;7, gear pin;8, the second half shaft gear;9, end cover;10, bolt;11, support ring;12, sealing plug;13, the second half shaft gear gasket;14, rotation axis;15, ring body support hole;16, shell support hole;17, stop end face;18, skeleton part;19, elastic sealing part;20, sealing ring;21, buckle structure;22, planetary disc gear installation cavity;23, oil inlet window;24, lubrication installation interface;25, first planetary disc gear shaft hole;26, second planetary disc gear shaft hole;27, installation pin hole. DETAILED DESCRIPTION

[0025] The specific implementation of the present application will be described below in conjunction with the accompanying drawings.

[0026] As shown in Figure 1 and Figure 2 , a coaxial differential of three planetary gears includes a differential housing and a differential gear assembly arranged in the differential housing, the differential housing includes a shell 1 and an end cover 9, the shell 1 has a mounting opening on one side, and the differential gear assembly can be assembled into the shell 1 through the mounting opening. The end cover 9 is arranged on the mounting opening side of the shell 1, the end cover 9 is connected to the mounting opening side end face of the shell 1 by a plurality of bolts 10, and the end cover 9 can seal and close the mounting opening of the shell 1.

[0027] In another alternative embodiment, the end cover 9 can also be welded to the mounting opening side end face of the shell 1.

[0028] As shown in Figure 3 and Figure 4 , the differential gear assembly includes three planetary gears 4 distributed on the same circumference, the planetary gears 4 are bevel gears, and the included angle between adjacent two planetary gears 4 is 120°. The three planetary gears 4 are rotatably connected to a planetary gear support structure, the front and rear of the three planetary gears 4 are respectively provided with a first half shaft gear 3 and a second half shaft gear 8, each of the three planetary gears 4 is meshingly connected with the first half shaft gear 3 and the second half shaft gear 8, and the first half shaft gear 3 and the second half shaft gear 8 can rotate around the rotation axis 14.

[0029] As shown in Figure 3 and Figure 4As shown, the planetary gear support structure comprises three planetary gear shafts 6, each of which is sleeved with a rotatable planetary gear 4, the central positions of the three planetary gear shafts 6 are provided with a support ring 11, and the support ring 11 is provided with ring body support holes 15 facing the end faces of the three planetary gear shafts 6. The shell 1 is provided with three radially-through shell support holes 16 in the circumferential direction, and the three shell support holes 16 are uniformly distributed along the circumferential direction. One end of each of the three planetary gear shafts 6 extends into the three ring body support holes 15 of the support ring 11, and the other end of each of the three planetary gear shafts 6 extends into the three shell support holes 16 of the shell 1.

[0030] Compared with the conventional differential, the number of planetary gears 4 is three, and the number of teeth of the corresponding gears on each planetary gear 4 is adjusted to adapt to the meshing rotation of the three planetary gears 4. The three planetary gears 4 are distributed at an angle of 120° and are connected in series on the differential lower shell through the planetary gear shafts 6, and the three planetary gear shafts 6 are finally inserted into the corresponding ring body support holes 15 of the support ring 11 and are fixed to each other to realize the supporting effect of the gear set on the planetary gears 4 during rotation of the gear set, thereby preventing the gear set from being disengaged. At the same time, when the torque is transmitted, the torque is evenly distributed among the three planetary gears 4 to reduce the torque load borne by each planetary gear 4.

[0031] The diameter of the planetary gear shaft 6 gradually decreases from one end to the other end, and the diameter of the end of the planetary gear shaft 6 connected to the ring body support hole 15 is smaller than the diameter of the end of the planetary gear shaft 6 connected to the shell support hole 16. The planetary gear shaft 6 has different diameters at the two ends, which can effectively reduce the size and thickness of the support ring 11 and meet the requirements of small-sized gear sets in the internal space.

[0032] As shown in Figure 2 and Figure 3 The other end of the three planetary gear shafts 6 is provided with a radially-through pin hole, and a gear pin 7 is arranged in the pin hole. The gear pin 7 extends into the shell pin hole arranged on the shell 1, and the planetary gear shaft 6 is positioned and installed in the differential housing through the gear pin 7.

[0033] As shown in Figure 2 and Figure 3 The planetary gear shaft 6 is sleeved with a planetary gear gasket 5, and the planetary gear gasket 5 is located between the planetary gear 4 and the inner wall of the differential housing.

[0034] As shown in Figure 2 and Figure 3As shown, the first half shaft gear 3 is provided with a protruding first gear shaft part at the center of the end face opposite to the second half shaft gear 8, the first gear shaft part is sleeved with the first half shaft gear gasket 2, and the first half shaft gear gasket 2 is located between the first half shaft gear 3 and the inner wall of the housing 1. The second half shaft gear 8 is provided with a protruding second gear shaft part at the center of the end face opposite to the first half shaft gear 3, the second gear shaft part is sleeved with the second half shaft gear gasket 13, and the second half shaft gear gasket 13 is located between the second half shaft gear 8 and the inner wall of the end cover 9.

[0035] The surface of the second gear shaft part of the second half shaft gear 8 is processed in a split manner, that is, the cooperation section with the inner hole of the end cover 9 and the section exceeding the inner hole are processed through a secondary grinding process, so as to ensure the size and low roughness of the section exceeding the inner hole, to meet the good cooperation with the sealing ring, and to ensure a relatively small height difference after the secondary grinding, thereby effectively ensuring the strength of the second gear shaft part of the second half shaft gear 8.

[0036] As shown in Figure 5 , the second half shaft gear 8 is provided with a half shaft gear shaft hole penetrating through the front and back at the center position, the half shaft gear shaft hole is provided with a sealing plug 12 at one end facing the first half shaft gear 3, and the sealing plug 12 is in interference fit with the inner wall of the half shaft gear shaft hole.

[0037] As shown in Figure 5 , the half shaft gear shaft hole is provided with an arc-shaped stop end face 17, the small-diameter end of the stop end face 17 has a cross-sectional size smaller than that of the sealing plug 12, and the stop end face 17 can limit the axial position of the sealing plug 12 to prevent the sealing plug 12 from being pulled out of the half shaft gear shaft hole.

[0038] As shown in Figure 5 and Figure 6 , the sealing plug 12 includes a skeleton part 18 and an elastic sealing part 19, the skeleton part 18 is made of a metal material such as iron, and has strong rigidity, and the elastic sealing part 19 is made of a rubber material and can be elastically deformed to realize sealing. The skeleton part 18 is provided with a through hole at the center position, the elastic sealing part 19 is provided with a T-shaped buckle structure 21 at the center position, the buckle structure 21 passes through the through hole of the skeleton part 18 and is clamped on the skeleton part 18, and the elastic sealing part 19 is tightly attached to the front end face of the skeleton part 18. The elastic sealing part 19 is provided with a protruding sealing ring 20 on the outer circumference, and the sealing ring 20 is in interference fit with the inner wall of the half shaft gear shaft hole of the second half shaft gear 8.

[0039] The sealing cover 12 can guarantee the differential to have good self-sealing function, the stop end face 17 can limit the axial position of the sealing cover 12, the sealing cover 12 cannot be taken out from the half shaft gear shaft hole, and the sealing cooperation between the sealing cover 12 and the second half shaft gear 8 can be effectively guaranteed.

[0040] As shown in Figure 1 Three planetary disc gear installation cavities 22 are arranged on the outer circumference of the shell 1, the three planetary disc gear installation cavities 22 are equidistantly distributed along the circumferential direction, and the planetary disc gear installation cavity 22 is an installation window reserved for the planetary disc gear of the speed reducer. One planetary disc gear of the speed reducer can be arranged in each planetary disc gear installation cavity 22, and the three planetary disc gears are also distributed at an angle of 120° and are arranged in a staggered manner on the circumference with the three planetary gears 4 distributed at an angle of 120°, and the axial and radial positions are avoided to be arranged. The first planetary disc gear shaft hole 25 and the second planetary disc gear shaft hole 26 are correspondingly arranged on the front and rear side walls of the planetary disc gear installation cavity 22, the planetary disc gear is arranged on the planetary disc gear shaft, and the two ends of the planetary disc gear shaft extend into the first planetary disc gear shaft hole 25 and the second planetary disc gear shaft hole 26 respectively. The mounting pin hole 27 is radially arranged on the side wall of the first planetary disc gear shaft hole 25, the mounting pin is arranged in the mounting pin hole 27, the mounting pin radially penetrates the planetary disc gear shaft, and the fixing of the planetary disc gear shaft is realized. The mounting pin hole 27 can be extended from the outer side wall of the shell 1 to the first planetary disc gear shaft hole 25, or can be extended from the outer side wall of the shell 1 to the first planetary disc gear shaft hole 25 and then penetrate the side wall at the opposite position.

[0041] The utility model discloses the mounting structure of planetary disc gear of speed reducer is reserved on the shell 1, through the mode of staggered arrangement of planetary disc gear and planetary gear, satisfy the same axle of whole vehicle power input and output, greatly reduce axial space and radial space, save weight.

[0042] As shown in Figure 1 The lubrication installation interface 24 is arranged on the outer circumference of the shell 1, the lubrication installation interface 24 can be connected with the active oil injection lubricating device, the oil inlet window 23 is arranged on the outer circumference of the shell 1, and the connected lubricating oil can enter the inside of the shell 1 through the oil inlet window 23.

[0043] The above description is the explanation of the utility model, not the limitation of the utility model, the range defined by the utility model is referred to the claims, and any form of modification can be made within the protection scope of the utility model.

Claims

1. A coaxial differential for a three-pinion planetary gear, comprising a differential housing and a differential gear assembly disposed within the differential housing, characterized in that: The differential gear assembly comprises three planetary gears (4) distributed on the same circumference, the included angle between two adjacent planetary gears (4) is 120°, the three planetary gears (4) are rotatably connected to the planetary gear support structure, the front and back of the three planetary gears (4) are respectively provided with the first half shaft gear (3) and the second half shaft gear (8), each of the three planetary gears (4) is in meshing connection with the first half shaft gear (3) and the second half shaft gear (8), and the first half shaft gear (3) and the second half shaft gear (8) can rotate around the rotation axis (14).

2. A three planetary gear coaxial differential according to claim 1, characterized in that: The differential housing comprises a housing (1) and an end cover (9), one side of the housing (1) is provided with a mounting opening, the end cover (9) is arranged on the side of the mounting opening, and the end cover (9) is connected to the end face of the side of the mounting opening of the housing (1). The end cover (9) can seal and close the mounting opening of the housing (1).

3. A three planetary gear coaxial differential according to claim 2, characterized in that: The planetary gear support structure comprises three planetary gear shafts (6), one rotatable planetary gear (4) is sleeved on each planetary gear shaft (6), the central positions of the three planetary gear shafts (6) are provided with a support ring (11), the end faces of the support ring (11) facing the three planetary gear shafts (6) are provided with ring body support holes (15), and the housing (1) is provided with three radially-through housing support holes (16) in the circumferential direction. One end of each of the three planetary gear shafts (6) extends into the three ring body support holes (15) of the support ring (11), and the other end of each of the three planetary gear shafts (6) extends into the three housing support holes (16) of the housing (1).

4. A three planetary gear coaxial differential according to claim 3, characterized in that: The other end of each of the three planetary gear shafts (6) is provided with a radially-through pin hole, a gear pin (7) is arranged in the pin hole, both ends of the gear pin (7) extend into the housing pin holes arranged on the housing (1), a planetary gear gasket (5) is sleeved on the planetary gear shaft (6), and the planetary gear gasket (5) is located between the planetary gear (4) and the inner wall of the differential housing.

5. A three planetary gear coaxial differential according to claim 4, characterized in that: The diameter size of the planetary gear shaft (6) gradually decreases from one end to the other end, and the diameter size of the end of the planetary gear shaft (6) connected to the ring body support hole (15) is smaller than the diameter size of the end of the planetary gear shaft (6) connected to the housing support hole (16).

6. A three planetary gear coaxial differential according to claim 1, characterized in that: A protruding first gear shaft part is arranged at the central position of the side end face of the first half shaft gear (3) away from the second half shaft gear (8), a first half shaft gear gasket (2) is sleeved on the first gear shaft part, the first half shaft gear gasket (2) is located between the first half shaft gear (3) and the inner wall of the housing (1), a protruding second gear shaft part is arranged at the central position of the side end face of the second half shaft gear (8) away from the first half shaft gear (3), a second half shaft gear gasket (13) is sleeved on the second gear shaft part, and the second half shaft gear gasket (13) is located between the second half shaft gear (8) and the inner wall of the end cover (9).

7. A three planetary gear coaxial differential according to claim 6, characterized in that: The second half axle gear (8) is provided with a front and rear through half axle gear shaft hole in the center position, the half axle gear shaft hole is provided with a sealing plug (12) facing one end of the first half axle gear (3), the sealing plug (12) and the inner wall of the half axle gear shaft hole are in interference fit, the half axle gear shaft hole is provided with a stop end face (17) of circular arc structure, the small diameter end of the stop end face (17) is smaller than the cross section size of the sealing plug (12), and the stop end face (17) can limit the axial position of the sealing plug (12).

8. A three-pinion coaxial differential according to claim 7, characterized in that: The sealing plug (12) comprises a framework part (18) and an elastic sealing part (19), the framework part (18) is provided with a through hole in the center position, the elastic sealing part (19) is provided with a buckle structure (21) of T-shaped structure in the center position, the buckle structure (21) passes through the through hole of the framework part (18) and is clamped on the framework part (18), the elastic sealing part (19) is tightly attached to the front end face of the framework part (18), the elastic sealing part (19) is provided with a protruding sealing ring (20) on the outer circumference, and the sealing ring (20) and the inner wall of the half axle gear shaft hole are in interference fit.

9. A three planetary gear coaxial differential according to claim 8, characterized in that: The shell (1) is provided with three planetary disc gear mounting cavities (22) on the outer circumference, one planetary disc gear can be arranged in each planetary disc gear mounting cavity (22), the three planetary disc gears are distributed at an angle of 120° and are staggered with the three planetary gears (4) on the circumference.

10. A coaxial differential for a three planetary gear according to claim 9, characterized in that: The shell (1) is provided with a lubricating mounting interface (24) on the outer circumference, and the shell (1) is provided with an oil inlet window (23) on the outer circumference.

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