CN112431907B

CN112431907B - Protective shell applied to differential mechanism and mounting method thereof

Info

Publication number: CN112431907B
Application number: CN202011472287.XA
Authority: CN
Inventors: 盛利; 周宁森; 王洪斌
Original assignee: Chongqing Zhong'ao Clutch Manufacturing Co ltd
Current assignee: Chongqing Zhong'ao Clutch Manufacturing Co ltd
Priority date: 2020-12-15
Filing date: 2020-12-15
Publication date: 2022-09-13
Anticipated expiration: 2040-12-15
Also published as: CN112431907A

Abstract

The invention relates to the technical field of differentials and discloses a protective shell applied to a differential and an installation method thereof. This be applied to differential mechanism's protective housing avoids appearing the not tight problem of meshing between planetary gear and the differential shaft gear, and then guarantees that planetary gear and differential shaft gear can be normal carry out work and guarantee the operation that differential mechanism can be normal, and then improves its life and reduces its cost of maintenance, and then avoids the car to appear damaging the time influence and the occurence of failure that cause in the driving process, and then improves navigating mate and crew's personal safety coefficient.

Description

Protective shell applied to differential mechanism and mounting method thereof

Technical Field

The invention relates to the technical field of differentials, in particular to a protective shell applied to a differential and an installation method thereof.

Background

The differential mechanism can realize a mechanism that left and right (or front and rear) driving wheels of the automobile rotate at different rotating speeds. Mainly comprises a left half shaft gear, a right half shaft gear, two planet gears and a gear carrier. The function is that when the automobile turns or runs on an uneven road surface, the left wheel and the right wheel roll at different rotating speeds, namely, the pure rolling motion of the driving wheels at two sides is ensured. The differential is provided for adjusting the difference in the rotational speeds of the left and right wheels. In four-wheel drive, all the wheels must be connected to drive four wheels, if the four wheels are mechanically connected, the vehicle cannot rotate at the same speed when the vehicle runs on a curve, and in order to make the curve running rotation speed of the vehicle substantially consistent, an intermediate differential is added to adjust the rotation speed difference between the front wheel and the rear wheel.

Differential mechanism is the rotation that utilizes a plurality of gears among the vehicle driving process, adjust the mechanism of drive wheel slew velocity, because the gear can rub at high-speed rotation in-process, consequently can produce a large amount of heats, untimely discharge heat from the shell can cause differential mechanism operation obstacle, present most differential mechanism protecting crust does not have good radiating effect usually, and then the inside gear of differential mechanism under the condition of long-time pivoted, can produce a large amount of heats, if the heat can not in time be got rid of can cause the phenomenon that produces the thermal expansion between the gear, and then cause the gear to damage and the gear between the phenomenon emergence of meshing not tight, and then cause the unable normal operating of differential mechanism.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides the protective shell applied to the differential mechanism and the installation method thereof, which have the advantages of well radiating heat generated by friction in the gear rotating process and the like, and solve the problems that most of differential mechanism protective shells usually do not have good radiating effect, further, gears in the differential mechanism can generate a large amount of heat under the condition of long-time rotation, and the phenomenon of thermal expansion between the gears can be caused if the heat is not timely removed.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a be applied to differential mechanism's protective housing, which comprises a housin, the casing sets up to link up from top to bottom, flange has been cup jointed to the surface mounting of casing, the upper end of casing is provided with the cap, set up threaded hole on the cap, the upper end of casing is the same set up threaded hole, threaded hole on the casing and the screw hole mutual adaptation on the cap, the inside threaded connection of screw hole has the bolt, flange's upper surface is provided with the gear wheel, equal same set up threaded hole on flange and the gear wheel, the same threaded connection in inside of screw hole has the bolt, the card hole has been seted up to the upper surface of cap, the inside rotation in card hole is connected with half axle gear, the gear groove has been seted up to the surface of casing, the inside rotation in gear groove is connected with planetary gear, the spout has been seted up to the inside of casing, the inside of spout is provided with heat dissipation mechanism.

Preferably, the quantity of side gear is two, and two side gear are the inside that the tooth is relative set up at the casing, and the quantity in gear groove is four, and four gear grooves are the cross setting and are in the surface of casing, and four gear grooves all extend to the inside of casing.

Preferably, four the inside of gear groove all rotates and is connected with planetary gear, is provided with the centre ring between four planetary gear, and the inside activity joint of the planetary gear of both sides has the dead lever about, and the dead lever runs through the centre ring and rotates with the centre ring and be connected, and the inside swing joint respectively of the planetary gear of both sides is in there being same dead lever around, and the dead lever does not rotate the joint with the centre ring with the one end of planetary gear contact equally, and four planetary gear are located between two half shaft gear, and four planetary gear and two half shaft gear intermeshing are connected.

Preferably, heat dissipation holes are formed in the outer surface of the shell, and a protective net is fixedly connected to the inside of each heat dissipation hole.

Preferably, heat dissipation mechanism includes the swivel becket, the swivel becket rotates to be connected in the inside of spout, and the spout is the ring form, and built-in groove has all been seted up to the inside upper and lower surface of spout, has seted up the exhaust hole on the inner wall of casing, and the exhaust hole communicates with the inside in built-in groove each other, has seted up the connecting hole on the inner wall in built-in groove, and connecting hole and louvre communicate each other.

Preferably, the swivel becket is the ring shape equally, the equal fixedly connected with fixed block in upper and lower surface of swivel becket, and the fixed block is the arc, and built-in hole has been seted up in the outside of fixed block, the inside fixedly connected with spring in built-in hole, the spring not with the one end fixedly connected with card pearl of built-in hole contact, card pearl and connecting hole mutual adaptation, fixed block sliding connection are in the inside in built-in groove.

Preferably, the diameter of the connecting hole is twice of the diameter of the heat dissipation hole.

Preferably, the inner wall of the rotating ring is provided with teeth, and the rotating ring is also in meshed connection with the side gear through the arranged teeth.

Preferably, the number of the sliding grooves is two, and the two rotating rings are respectively in meshing connection with the two side gears.

A method for mounting a protective shell applied to a differential comprises the following steps:

the first step is as follows: firstly, forging the shell, then respectively placing the two rotating rings into the sliding grooves, further enabling the fixed block to be located in the built-in groove, further placing a half axle gear into the lower end of the interior of the shell in a tooth-up mode, further respectively placing the four planet gears into the four gear grooves, further placing a second half axle gear into the upper end of the interior of the shell in a tooth-down mode, further enabling the two half axle gears to be in meshed connection with the two rotating rings, and simultaneously enabling the two half axle gears to be in meshed connection with the four planet gears;

the second step is that: then selecting three fixed rods, and further fixedly connecting one fixed rod to the insides of the planetary gears on the left side and the right side, and further fixedly connecting the other two fixed rods to the insides of the planetary gears on the front side and the rear side respectively;

the third step: and then fix gear wheel and flange through the bolt, and then fix the cap through the bolt with the upper end of casing, and then accomplish the equipment to differential mechanism, and then will assemble and install between the differential mechanism and the car actuating mechanism who accomplishes.

(III) advantageous effects

Compared with the prior art, the invention provides the protective shell applied to the differential mechanism and the installation method thereof, and the protective shell has the following beneficial effects:

1. the protective shell applied to the differential mechanism and the installation method thereof are characterized in that the rotating ring is connected with the half axle gear in a meshing manner, when the half axle gear rotates, the rotating ring is driven to rotate, the rotating ring drives the fixing block to rotate in the built-in groove, the fixing block drives the clamping bead to move in a rotating manner, when the clamping bead contacts with the inner wall of the built-in groove, the clamping bead retracts into the built-in hole, the clamping bead does not shield the connecting hole, heat produced by friction between the planetary gear and the half axle gear firstly enters the built-in groove through the exhaust hole and then is discharged out of the shell through the heat dissipation hole after being gathered through the connecting hole, and thermal expansion between the planetary gear and the half axle gear caused by the fact that the heat produced by friction cannot be effectively discharged out between the planetary gear and the half axle gear is further reduced, and then avoid appearing the not tight problem of meshing between planetary gear and the half shaft gear, and then guarantee that planetary gear and half shaft gear can be normal the work and guarantee that differential mechanism can normal operation, and then improve its life and reduce its cost of maintenance, and then avoid the car to appear damaging the time influence and the occurence of failure that cause in the driving process, and then improve navigating mate and passenger's personal safety coefficient.

2. According to the protective shell applied to the differential mechanism and the installation method thereof, the connecting holes can be shielded through the arranged clamping beads, and then when the differential mechanism does not work, the clamping beads are clamped into the connecting holes, so that the phenomenon that outside cold air enters the shell can be avoided, and then the planetary gear and the half axle gear are damaged, so that the service lives of the planetary gear and the half axle gear are prolonged, and the maintenance and replacement costs of the planetary gear and the half axle gear are reduced.

3. This be applied to protective housing of differential mechanism and installation method thereof, be the connected state through between the louvre that sets up and the connecting hole, and then when needing planetary gear and side gear to beat the oil lubrication, and then need not unpack the casing apart and lubricate it, can be directly pour into the inside of casing into lubricating oil through the louvre, and then lubricating oil flows into the inside of built-in groove through the connecting hole, and then flow through the exhaust hole, and then the centrifugal force that produces along with planetary gear and side gear's rotation can be with even dispersion of lubricating oil to planetary gear and side gear, and then improve its work efficiency, reduce the time wasted of dismantling the casing, and then reduce operating personnel's intensity of labour.

4. This be applied to differential mechanism's protective housing and mounting method, the diameter through the connecting hole that sets up is the twice of louvre diameter, and then form a bell mouth, and then make the heat can be better assemble in the inside of connecting hole, and then the diameter through the louvre is less than the diameter of connecting hole, and then make the heat when volatilizing away, speed is faster, the inside through the louvre that sets up is provided with the protection network simultaneously, and then can effectually avoid outside impurity to get into the inside of casing, and then avoid damaging between planetary gear and the side gear, and then guarantee the stability of differential mechanism during operation.

5. According to the protective shell applied to the differential mechanism and the mounting method of the protective shell, the shell cover and the shell can be quickly fixed through the arranged threaded holes and the arranged bolts, the connecting flange and the gear wheel can be quickly fixed, the working efficiency is improved, the assembling time is saved, the planetary gear can be prevented from being separated from the inside of the gear groove through the arranged fixing rod and the center ring in a rotating and clamping mode, the stability of the differential mechanism in operation is improved, and the differential mechanism can be guaranteed to normally operate and improve power.

Drawings

FIG. 1 is a schematic structural view of a protective casing for a differential according to the present invention;

FIG. 2 is a schematic view of the housing structure of the present invention;

FIG. 3 is a schematic view of the chute structure of the present invention;

FIG. 4 is an enlarged view of the structure at A in FIG. 3 according to the present invention;

FIG. 5 is a schematic view of a rotating ring according to the present invention;

FIG. 6 is an enlarged view of the structure at B in FIG. 5 according to the present invention.

In the figure: the device comprises a shell 1, a connecting flange 2, a gearwheel 3, a shell cover 4, a threaded hole 5, a bolt 6, a half axle gear 7, a clamping hole 8, a heat dissipation hole 9, a protective screen 10, a gear groove 11, a planet gear 12, a fixed rod 13, an exhaust hole 14, a sliding groove 15, a built-in groove 16, a connecting hole 17, a rotating ring 18, teeth 19, a fixed block 20, a built-in hole 21, a spring 22 and a clamping bead 23.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-6, the present invention provides a new technical solution: a protective shell applied to a differential mechanism comprises a shell body 1, wherein the shell body 1 is arranged to be vertically communicated, a connecting flange 2 is fixedly sleeved on the outer surface of the shell body 1, a shell cover 4 is arranged at the upper end of the shell body 1, a threaded hole 5 is formed in the shell cover 4, the upper end of the shell body 1 is also provided with a threaded hole 5, the threaded hole 5 in the shell body 1 is matched with the threaded hole 5 in the shell cover 4, a bolt 6 is connected with the inner thread of the threaded hole 5, a large gear 3 is arranged on the upper surface of the connecting flange 2, the threaded hole 5 is also formed in the connecting flange 2 and the large gear 3, the bolt 6 is connected with the inner thread of the threaded hole 5, and further, through the arranged threaded hole 5 and the bolt 6, the shell cover 4 and the shell body 1 can be quickly fixed, and the connecting flange 2 and the large gear 3 can be quickly fixed, so that the working efficiency is improved, the assembly time is saved;

the upper surface of the shell cover 4 is provided with a clamping hole 8, the inside of the clamping hole 8 is rotatably connected with half-axle gears 7, the number of the half-axle gears 7 is two, the two half-axle gears 7 are arranged inside the shell 1 in a tooth-opposite mode, the outer surface of the shell 1 is provided with gear grooves 11, the number of the gear grooves 11 is four, the four gear grooves 11 are arranged on the outer surface of the shell 1 in a cross shape, the four gear grooves 11 all extend to the inside of the shell 1, the opening diameter of the four gear grooves 11 in the shell 1 is larger than that in the outside, the insides of the four gear grooves 11 are rotatably connected with planetary gears 12, a central ring is arranged between the four planetary gears 12, fixed rods 13 are movably clamped inside the planetary gears 12 on the left side and the right side, the fixed rods 13 penetrate through the central ring and are rotatably connected with the central ring, the insides of the planetary gears 12 on the front side and the rear side are respectively movably connected with the same fixed rods 13, one end, which is not contacted with the planetary gear 12, of the fixed rod 13 is also rotationally clamped with the central ring, the four planetary gears 12 are positioned between the two half shaft gears 7, the four planetary gears 12 are meshed with the two half shaft gears 7 and are connected with the two half shaft gears 7, and the planetary gears 12 and the half shaft gears 7 are of the existing structure and are not described in detail herein;

the outer surface of the shell 1 is provided with heat dissipation holes 9, the inside of each heat dissipation hole 9 is fixedly connected with a protective net 10, the inner wall of the shell 1 is provided with a sliding groove 15, the sliding groove 15 is annular, the upper surface and the lower surface of the inside of the sliding groove 15 are both provided with built-in grooves 16, the inner wall of the shell 1 is provided with exhaust holes 14, the exhaust holes 14 are communicated with the inside of the built-in grooves 16, the inner wall of the built-in grooves 16 is provided with connecting holes 17, the connecting holes 17 are communicated with the heat dissipation holes 9, the diameter of the connecting holes 17 is twice of the diameter of the heat dissipation holes 9, a conical hole is formed, heat can be better gathered inside the connecting holes 17, the diameter of the heat dissipation holes 9 is smaller than the diameter of the connecting holes 17, the heat is volatilized, the speed is higher, and the protective net 10 is arranged inside the heat dissipation holes 9, therefore, external impurities can be effectively prevented from entering the shell 1, the planetary gear 12 and the half axle gear 7 are prevented from being directly damaged, and the stability of the differential during working is further ensured;

the inner part of the sliding chute 15 is rotatably connected with a rotating ring 18, the rotating ring 18 is also in a ring shape, the inner wall of the rotating ring 18 is provided with teeth 19, the rotating ring 18 is also meshed with the half axle gear 7 through the provided teeth 19, the upper surface and the lower surface of the rotating ring 18 are fixedly connected with fixing blocks 20, the fixing blocks 20 are in an arc shape, the outer side of each fixing block 20 is provided with a built-in hole 21, the inner part of the built-in hole 21 is fixedly connected with a spring 22, one end of the spring 22, which is not contacted with the built-in hole 21, is fixedly connected with a clamping bead 23, the clamping beads 23 are mutually matched with the connecting holes 17, the number of the fixing blocks 20 is multiple, the structures of the fixing blocks 20 are the same, the fixing blocks 20 are respectively and slidably connected in the built-in groove 16, the number of the sliding chutes 15 is two, the inner structures of the two sliding chutes 15 are the same, and the two rotating rings 18 are respectively meshed with the two half axle gears 7, and then through the meshing connection of the rotating ring 18 and the half axle gear 7, and when the half axle gear 7 rotates, the rotating ring 18 is further driven to rotate, and further the rotation of the rotating ring 18 drives the fixed block 20 to rotate inside the built-in groove 16, and further the rotation of the fixed block 20 drives the clamping bead 23 to move, and further when the clamping bead 23 contacts the inner wall of the built-in groove 16, the clamping bead 23 retracts inside the built-in hole 21, at this time, the clamping bead 23 does not shield the connecting hole 17, and further the heat produced by friction between the planetary gear 12 and the half axle gear 7 enters the built-in groove 16 through the vent hole 14, and then is discharged out of the inside of the housing 1 through the heat dissipation hole 9 after being gathered through the connecting hole 17, so as to reduce the thermal expansion between the planetary gear 12 and the half axle gear 7 caused by the heat produced by friction being unable to be effectively discharged out from the planetary gear 12 and the half axle gear 7, further avoiding the problem of loose meshing between the planet gear 12 and the side gear 7, further ensuring the normal operation of the planet gear 12 and the side gear 7 and the normal operation of the differential, further shielding the connecting hole 17 by the arranged clamping bead 23, further clamping the clamping bead 23 into the connecting hole 17 when the differential does not operate, further avoiding the entry of external cold air into the housing 1, further causing loss to the planet gear 12 and the side gear 7, further prolonging the service life of the planet gear 12 and the side gear 7, further reducing the maintenance and replacement cost, meanwhile, communicating the connecting hole 17 with the heat dissipation hole 9, further avoiding the disassembly of the housing 1 for lubricating the planet gear 12 and the side gear 7 when the oil lubrication is required to be performed on the planet gear 12 and the side gear 7, can directly pour into the inside of casing 1 with lubricating oil through louvre 9, and then lubricating oil flows into the inside of built-in groove 16 through connecting hole 17, and then flows out through exhaust hole 14, and then the centrifugal force that produces along with the rotation of planetary gear 12 and side gear 7 can be with the even dispersion of lubricating oil to planetary gear 12 and side gear 7 on, and then improve its work efficiency, reduce the time of dismantling the waste of casing 1, and then reduce operating personnel's intensity of labour.

the first step is as follows: firstly, forging the shell 1, then respectively placing the two rotating rings 18 into the sliding grooves 15, further enabling the fixed block 20 to be located inside the built-in groove 16, further placing one half axle gear 7 into the lower end of the interior of the shell 1 in a tooth-up manner, further respectively placing the four planet gears 12 into the four gear grooves 11, further placing the second half axle gear 7 into the upper end of the interior of the shell 1 in a tooth-down manner, further enabling the two half axle gears 7 to be in meshed connection with the two rotating rings 18, and simultaneously enabling the two half axle gears 7 to be in meshed connection with the four planet gears 12;

the second step is that: further selecting three fixed rods 13, and further fixedly connecting one fixed rod 13 to the insides of the planetary gears 12 on the left side and the right side, and further fixedly connecting the other two fixed rods 13 to the insides of the planetary gears 12 on the front side and the rear side respectively;

the third step: and then fix gear wheel 3 and flange 2 through bolt 6, and then fix cap 4 and the upper end of casing 1 through bolt 6, and then accomplish the equipment to differential mechanism, and then will assemble and install between the differential mechanism of accomplishing and the car actuating mechanism.

The working principle is as follows: and then through the meshing connection of the rotating ring 18 and the half axle gear 7, and when the half axle gear 7 rotates, the rotating ring 18 is further driven to rotate, and further the rotation of the rotating ring 18 drives the fixed block 20 to rotate inside the built-in groove 16, and further the rotation of the fixed block 20 drives the clamping bead 23 to move, and further when the clamping bead 23 contacts the inner wall of the built-in groove 16, the clamping bead 23 retracts inside the built-in hole 21, at this time, the clamping bead 23 does not shield the connecting hole 17, and further the heat produced by friction between the planetary gear 12 and the half axle gear 7 enters the built-in groove 16 through the vent hole 14, and then is discharged out of the inside of the housing 1 through the heat dissipation hole 9 after being gathered through the connecting hole 17, so as to reduce the thermal expansion between the planetary gear 12 and the half axle gear 7 caused by the heat produced by friction being unable to be effectively discharged out from the planetary gear 12 and the half axle gear 7, therefore, the problem of loose meshing between the planet gear 12 and the side gear 7 is avoided, the planet gear 12 and the side gear 7 can be ensured to work normally, the differential can operate normally, the connecting hole 17 can be shielded through the arranged clamping bead 23, the clamping bead 23 is clamped into the connecting hole 17 when the differential does not work, cold air outside can be prevented from entering the shell 1 to damage the planet gear 12 and the side gear 7, the service lives of the planet gear 12 and the side gear 7 are prolonged, the maintenance and replacement costs are reduced, meanwhile, the planet gear 12 and the side gear 7 are in a communication state through the arranged heat dissipation holes 9 and the connecting hole 17, and when oil pumping lubrication is required to be carried out on the planet gear 12 and the side gear 7, the shell 1 is not required to be disassembled for lubrication, can directly pour into the inside of casing 1 with lubricating oil through louvre 9, and then lubricating oil flows into the inside of built-in groove 16 through connecting hole 17, and then flows out through exhaust hole 14, and then the centrifugal force that produces along with the rotation of planetary gear 12 and side gear 7 can be with the even dispersion of lubricating oil to planetary gear 12 and side gear 7 on, and then improve its work efficiency, reduce the time of dismantling the waste of casing 1, and then reduce operating personnel's intensity of labour.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A protective casing applied to a differential mechanism comprises a casing (1), and is characterized in that: the shell (1) is arranged to be vertically communicated, a connecting flange (2) is fixedly sleeved on the outer surface of the shell (1), a shell cover (4) is arranged at the upper end of the shell (1), a threaded hole (5) is formed in the shell cover (4), the upper end of the shell (1) is also provided with the threaded hole (5), the threaded hole (5) in the shell (1) is matched with the threaded hole (5) in the shell cover (4), a bolt (6) is connected to the inner thread of the threaded hole (5), a large gear (3) is arranged on the upper surface of the connecting flange (2), the threaded holes (5) are formed in the connecting flange (2) and the large gear (3) in the same way, the bolt (6) is connected to the inner thread of the threaded hole (5) in the same way, a clamping hole (8) is formed in the upper surface of the shell cover (4), a half shaft gear (7) is rotatably connected to the inner part of the clamping hole (8), a gear groove (11) is formed in the outer surface of the shell (1), a planetary gear (12) is rotatably connected inside the gear groove (11), a sliding groove (15) is formed inside the shell (1), and a heat dissipation mechanism is arranged inside the sliding groove (15);

the heat dissipation mechanism comprises a rotating ring (18), the rotating ring (18) is rotatably connected inside a sliding groove (15), the sliding groove (15) is annular, built-in grooves (16) are formed in the upper surface and the lower surface of the inside of the sliding groove (15), exhaust holes (14) are formed in the inner wall of the shell (1), the exhaust holes (14) are communicated with the inside of the built-in grooves (16), connecting holes (17) are formed in the inner wall of the built-in grooves (16), and the connecting holes (17) are communicated with the heat dissipation holes (9);

the utility model discloses a quick-witted, including swivel becket (18), the equal fixedly connected with fixed block (20) in upper and lower surface of swivel becket (18) is the ring shape equally, fixed block (20) are the arc, built-in hole (21) have been seted up in the outside of fixed block (20), inside fixedly connected with spring (22) of built-in hole (21), spring (22) do not block pearl (23) with the one end fixedly connected with of built-in hole (21) contact, block pearl (23) and connecting hole (17) mutual adaptation, the inside in built-in groove (16) of fixed block (20) sliding connection.

2. A protective casing for a differential gear as claimed in claim 1, wherein: the number of the half shaft gears (7) is two, the two half shaft gears (7) are arranged inside the shell (1) in a mode that teeth are opposite, the number of the gear grooves (11) is four, the four gear grooves (11) are arranged on the outer surface of the shell (1) in a cross shape, and the four gear grooves (11) all extend into the shell (1).

3. A protective casing for a differential gear as claimed in claim 1, wherein: four the inside of gear groove (11) all rotates and is connected with planetary gear (12), be provided with the centre ring between four planetary gear (12), the inside activity joint of the planetary gear (12) of the left and right sides has dead lever (13), dead lever (13) run through the centre ring and are connected with the centre ring rotation, the inside swing joint of planetary gear (12) of front and back both sides has same dead lever (13) respectively, dead lever (13) do not rotate the joint with the centre ring with the one end that planetary gear (12) contacted equally, four planetary gear (12) are located between two differential side gear (7), four planetary gear (12) are connected with two differential side gear (7) intermeshing.

4. A protective casing for a differential gear as claimed in claim 1, wherein: the heat dissipation hole (9) is formed in the outer surface of the shell (1), and a protective net (10) is fixedly connected inside the heat dissipation hole (9).

5. A protective casing for a differential gear as claimed in claim 1, wherein: the diameter of the connecting hole (17) is twice that of the heat dissipation hole (9).

6. A protective casing for a differential gear as claimed in claim 1, wherein: the inner wall of the rotating ring (18) is provided with teeth (19), and the rotating ring (18) is also meshed and connected with the half shaft gear (7) through the arranged teeth (19).

7. A protective casing applied to a differential gear according to claim 1, wherein: the number of the sliding grooves (15) is two, and the two rotating rings (18) are respectively meshed and connected with the two half shaft gears (7).

8. A method for installing a protective shell applied to a differential is characterized in that:

the first step is as follows: firstly, forging the shell (1), respectively placing two rotating rings (18) into a sliding groove (15), further enabling a fixed block (20) to be located inside an embedded groove (16), further placing one half shaft gear (7) into the lower end of the interior of the shell (1) in a tooth-up mode, further respectively placing four planet gears (12) into the interior of four gear grooves (11), further placing a second half shaft gear (7) into the upper end of the interior of the shell (1) in a tooth-down mode, further enabling the two half shaft gears (7) to be in meshing connection with the two rotating rings (18), and simultaneously enabling the two half shaft gears (7) to be in meshing connection with the four planet gears (12);

the second step is that: further selecting three fixed rods (13), further fixedly connecting one fixed rod (13) to the insides of the planetary gears (12) at the left side and the right side, and further fixedly connecting the other two fixed rods (13) to the insides of the planetary gears (12) at the front side and the rear side respectively;

the third step: and then the large gear (3) and the connecting flange (2) are fixed through the bolts (6), and further the shell cover (4) and the upper end of the shell (1) are fixed through the bolts (6), so that the differential is assembled, and the assembled differential and the automobile driving mechanism are installed.