CN115045972A

CN115045972A - Differential device and model vehicle

Info

Publication number: CN115045972A
Application number: CN202210631540.4A
Authority: CN
Inventors: 侯志坤
Original assignee: Foshan Zhengze Model Technology Co ltd
Current assignee: Foshan Zhengze Model Technology Co ltd
Priority date: 2022-06-06
Filing date: 2022-06-06
Publication date: 2022-09-13

Abstract

The invention discloses a differential device and a model car, wherein the differential device comprises: a housing; a differential assembly located within the housing, the differential assembly including a main drive gear member, a planetary gear set, a first gear member, a synchronizing gear member, a second gear member, and a sliding gear member; a push spring; the switching assembly is used for controlling the sliding gear piece to be meshed with or separated from the synchronous gear piece and comprises a shifting fork, a switching shaft, a switching arm, a pushing torsion spring and a driving motor, one end of the switching arm is fixed on the switching shaft, and the other end of the switching arm is connected with the driving motor; two ends of the pushing torsion spring are respectively connected to the switching arm and the shell; the pushing torsion spring is used for continuously applying force to the switching arm, so that the shifting fork continuously applies force back to the synchronous gear piece to the sliding gear piece.

Description

Differential device and model vehicle

Technical Field

The invention relates to the technical field of vehicle transmission, in particular to a differential device and a model vehicle.

Background

After the power of the engine of the vehicle is transmitted through the components such as the transmission, the transmission shaft and the like, the power is finally transmitted to a drive axle, and then the drive axle is distributed to half shafts left and right to drive wheels to rotate, wherein the drive axle is the last assembly, and the main components of the drive axle are a speed reducer and a differential mechanism. The differential is generally composed of planetary gears, a planetary carrier, a side gear and the like. The power of the engine enters the differential mechanism through the transmission shaft to directly drive the planet wheel carrier, and then the planet wheel drives the left half shaft and the right half shaft to respectively drive the left wheel and the right wheel.

When the automobile runs straight, the rotating speeds of the left wheel, the right wheel and the planet wheel carrier are equal and are in a balanced state, and the balanced state of the left wheel, the right wheel and the planet wheel carrier is damaged when the automobile turns, so that the rotating speed of the inner side wheel is reduced, and the rotating speed of the outer side wheel is increased. The differential mechanism has the function of allowing the half shafts on the two sides to rotate at different rotating speeds while transmitting power to the half shafts on the two sides, so that wheels on the two sides can run in an unequal distance mode in a pure rolling mode as far as possible, and the friction between tires and the ground is reduced. However, the differential mechanism has the disadvantage that when the vehicle encounters a bad road surface, such as sand or mud, the wheels at the other end of the differential mechanism lose power completely and are kept still as long as one wheel falls into a slip state. Therefore, when one driving wheel slips, the planet wheel carrier and the half shaft are locked into a whole, the differential mechanism loses the differential action, and the whole torque can be transferred to the driving wheel at the other side,

at present, the existing differential has a differential lock for opening or closing the differential, when the gear set of the differential is partially completely locked, the differential action of the differential is disabled, so that the wheels on both sides can obtain the same power; and differential lock on present differential mechanism usually directly makes the shift fork make a round trip to rotate and then makes the shift fork make a round trip to promote the switching dish through motor drive shift fork, and the motor needs to continue to circular telegram, makes the in-process of gear train part complete locking at the motor moreover because two tooth portions can appear died and the condition of not meshing for motor and gear train receive the damage easily.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the invention provides a differential device and a model vehicle.

In a first aspect, an embodiment of the present invention provides a differential device, including:

a housing;

the differential component is positioned in the shell and comprises a main driving gear part, a planetary gear set, a first gear part, a synchronous gear part, a second gear part and a sliding gear part, wherein the main driving gear part is meshed with the synchronous gear part, the synchronous gear part is sleeved on the first gear part and is meshed with the planetary gear set, the planetary gear set is respectively meshed with the first gear part and the second gear part, the sliding gear part is sleeved on the second gear part and can move along the axial direction of the second gear part, and the sliding gear part and the second gear part synchronously rotate;

a push spring within the housing for continuously applying a force to the sliding gear member toward the synchronizing gear member;

the switching assembly is used for controlling the sliding gear piece to be meshed with or separated from the synchronous gear piece and comprises a shifting fork, a switching shaft, a switching arm, a pushing torsion spring and a driving motor, the switching shaft penetrates through the shell and can rotate relative to the shell, the shifting fork is fixed on the switching shaft and abuts against the sliding gear piece, one end of the switching arm is fixed on the switching shaft, and the other end of the switching arm is connected with the driving motor; two ends of the pushing torsion spring are respectively connected with the switching arm and the shell; the pushing torsion spring is used for continuously applying force to the switching arm, so that the shifting fork continuously applies force back to the synchronous gear piece to the sliding gear piece.

The differential device according to the embodiment of the invention has at least the following technical effects: the driving motor applies force to the switching arm in a direction opposite to that of the pushing torsion spring, the driving motor and the pushing torsion spring jointly apply force to the switching arm and convert the force to the sliding gear piece by the shifting fork, and when the force to the sliding gear piece by the shifting fork is larger than the force to the sliding gear piece by the pushing spring, the sliding gear piece is separated from the synchronous gear piece; when the force of the shift fork to the sliding gear piece is smaller than the force of the pushing spring to the sliding gear piece, the sliding gear piece moves to be engaged with the synchronous gear piece.

According to some embodiments of the present invention, when the driving motor is stopped, a force applied to the sliding gear piece by the shift fork is greater than a force applied to the sliding gear piece by the push spring, the sliding gear piece being separated from the synchronizing gear piece; when driving motor opens, driving motor is right the part can be offset to the power of switching the arm the promotion torsional spring is right the power of switching the arm, so that it is right to promote the spring sliding gear spare power of exerting more than the shift fork is right sliding gear spare power of exerting, sliding gear spare move to with synchronous gear spare meshing.

According to some embodiments of the present invention, the first gear member comprises a first inner tooth portion, a first shaft and a first outer tooth portion, both ends of the first shaft are fixedly connected to the first inner tooth portion and the first outer tooth portion respectively, the first inner tooth portion is meshed with the planetary gear set, and the first outer tooth portion is meshed with the wheel of the model car.

According to some embodiments of the present invention, the second gear member includes a second inner tooth portion, a second shaft and a second outer tooth portion, two ends of the second shaft are respectively and fixedly connected to the second inner tooth portion and the second outer tooth portion, the second inner tooth portion is engaged with the planetary gear set, the second outer tooth portion is engaged with a wheel of the model car, the sliding gear member is sleeved on the second shaft, the sliding gear member can slide along an axis of the second shaft, and the sliding gear member and the second shaft rotate synchronously.

According to some embodiments of the present invention, the sliding gear member includes a sliding inner gear portion, a sliding cylinder and a sliding disk, two ends of the sliding cylinder are respectively and fixedly connected to the sliding inner gear portion and the sliding disk, the sliding inner gear portion, the sliding cylinder and the sliding disk are integrally injection-molded, the sliding inner gear portion, the sliding cylinder and the sliding disk are all sleeved on the second shaft, and the sliding inner gear portion is engaged with or separated from the synchronizing gear member.

According to some embodiments of the present invention, a fixed disk is disposed on the second shaft, the fixed disk is sleeved and fixed on the second shaft, the fixed disk is located on one side of the sliding disk, which is far away from the sliding inner tooth portion, the pushing spring is sleeved on the second shaft, the pushing spring is located between the sliding disk and the fixed disk, two ends of the pushing spring are respectively connected with the sliding disk and the fixed disk, and the pushing spring is in a compressed state.

According to some embodiments of the invention, the fork is located between the sliding inner tooth and the sliding disc, the fork abutting a side of the sliding disc adjacent to the sliding inner tooth.

According to some embodiments of the present invention, the housing is provided with a steel bar assembly, the steel bar assembly includes a connecting seat and a long steel bar, the long steel bar is inserted into the connecting seat and can slide relative to the connecting seat, the connecting seat is fixedly installed in the housing, one end of the long steel bar is connected to the driving motor, the other end of the long steel bar is connected to the switching arm, the driving motor can apply a force to the switching arm through the long steel bar, and the force applied to the switching arm by the driving motor is opposite to the force applied to the switching arm by the push torsion spring.

In a second aspect, embodiments of the present invention further provide a model vehicle including the differential device according to the embodiment of the first aspect of the present invention.

The model car provided by the embodiment of the invention at least has the following technical effects: when the differential is required to play a differential action, the driving motor is not started, so that the force of the shifting fork on the sliding gear piece is greater than the force of the pushing spring on the sliding gear piece, and the sliding gear piece is separated from the synchronous gear piece; when the differential does not play a differential role, the driving motor is started, so that the force of the shifting fork on the sliding gear piece is smaller than the force of the pushing spring on the sliding gear piece, and the sliding gear piece moves to be meshed with the synchronous gear piece.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic structural view of a differential device according to some embodiments of the present invention;

FIG. 2 is a schematic illustration of the differential device of some embodiments of the present invention from another angle;

FIG. 3 is a front view of a differential device according to some embodiments of the present invention;

FIG. 4 is a rear view of the differential device of some embodiments of the present invention;

FIG. 5 is a schematic illustration of a differential device of some embodiments of the present invention with the housing hidden;

FIG. 6 is an exploded view of FIG. 5;

fig. 7 is a schematic structural diagram of a switching assembly according to some embodiments of the invention.

Reference numerals:

a housing 100, a main driving gear member 110, a planetary gear set 120, a push spring 130, a synchronizing gear member 140, a steel bar assembly 150, a connecting seat 151, a long steel bar 152;

a first gear member 200, a first inner tooth portion 210, a first outer tooth portion 220, a first shaft 230, a first groove 231;

a second gear member 300, a second inner tooth 310, a second outer tooth 320, a second shaft 330, a second groove 331, a fixed disk 332;

a sliding gear member 400, a sliding inner gear portion 410, a sliding cylinder 420, a sliding disk 430;

switching assembly 500, fork 510, switching shaft 520, switching arm 530, pushing torsion spring 540.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, if there are first and second described only for the purpose of distinguishing technical features, it is not understood that relative importance is indicated or implied or that the number of indicated technical features or the precedence of the indicated technical features is implicitly indicated or implied.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

The embodiments of the present invention will be further explained with reference to the drawings.

According to some embodiments of the present invention, referring to fig. 1 to 7, the differential device includes a case 100, a differential assembly, a push spring 130, and a switching assembly 500; referring to fig. 5 to 6, a differential assembly is located in the housing 100, the differential assembly including a main driving gear member 110, a planetary gear set 120, a first gear member 200, a synchronizing gear member 140, a second gear member 300, and a sliding gear member 400, the main driving gear being located at the rear of the synchronizing gear member 140, the main driving gear being engaged with the synchronizing gear member 140, the planetary gear set 120 being located inside the synchronizing gear member 140 and engaged with the synchronizing gear member 140, the synchronizing gear member 140 being fitted over one end of the first gear member 200, the first gear member 200 being located at the left side of the planetary gear set 120, the second gear member 300 being located at the right side of the planetary gear set 120, the planetary gear set 120 being engaged with the first gear member 200 and the second gear member 300, respectively; when the main driving gear 110 rotates, the synchronizing gear 140 rotates along with the main driving gear 110, and the synchronizing gear 140 drives the planetary gear set 120 to rotate, the rotation of the planetary gear set 120 can respectively drive the first gear 200 and the second gear 300 to rotate, the first gear 200 and the second gear 300 can realize differential rotation, and the planetary gear differential principle is a conventional technical principle of those skilled in the art, and is not described herein again; the sliding gear part 400 is sleeved on the second gear part 300 and can move along the axial direction of the second gear part 300, the sliding gear part 400 can be engaged with or separated from the synchronizing gear part 140, the rotation of the sliding gear part 400 can drive the second gear part 300 to rotate, and the sliding gear part 400 and the second gear part 300 synchronously rotate; the push spring 130 is located in the housing 100, and the push spring 130 can continuously apply a force toward the timing gear member 140, i.e., a leftward force, to the sliding gear member 400; referring to fig. 5 to 7, the switching assembly 500 includes a shift fork 510, a switching shaft 520, a switching arm 530, a pushing torsion spring 540 and a driving motor, the driving motor is not shown in the drawings, the switching shaft 520 penetrates into the interior of the housing 100 and can rotate relative to the housing 100, the shift fork 510 is fixed on the switching shaft 520 and abuts against the sliding gear piece 400, one end of the switching arm 530 is fixedly installed on the switching shaft 520, the other end of the switching arm 530 is connected with the driving motor, one end of the pushing torsion spring 540 is connected to the switching arm 530, the other end of the pushing torsion spring 540 is connected to the housing 100, the pushing torsion spring 540 can continuously apply force to the switching arm 530 so that the switching arm 530 and the switching shaft 520 continuously have a tendency to rotate, so that the shift fork 510 fixed on the switching shaft 520 continuously applies force to the sliding gear piece 400, which is opposite to the synchronous gear piece 140, i.e., force to the right.

It should be noted that when the motor is not started, the torsion force continuously applied to the switching arm 530 by the torsion spring 540 is converted into the rightward force continuously applied to the sliding gear piece 400 by the shift fork 510, and the magnitude of the force is F1; the pushing spring 130 continues to apply a leftward force to the sliding gear piece 400, which force has a magnitude of F2, and satisfies that F1 > F2:

when the driving motor is not activated, the shift fork 510 can push the sliding gear member 400 to move rightward to a position separated from the timing gear member 140 and make the sliding gear member 400 abut against the inner wall of the casing 100, at which time the sliding gear member 400 remains stationary and the differential device performs a differential function.

When the driving motor is started, the force exerted on the switching arm 530 by the driving motor is opposite to the direction of the force exerted on the switching arm 530 by the torsion spring 540, the force exerted on the switching arm 530 by the driving motor is F3, and F3 is gradually increased; when F1 > F2+ F3, the sliding gear piece 400 remains stationary; when F3 is gradually increased to satisfy: with F2+ F3 > F1, the sliding gear member 400 moves to the left until it engages the synchronizing gear member 140, at which time the differential does not act as a differential.

It should be noted that when F2+ F3 > F1, during the sliding leftward movement until the synchronous gear member 140 is engaged, F3 does not gradually increase, and then F3 < F1.

It can be understood that when the driving motor is not activated, the shift fork 510 continuously applies a rightward force F1 to the sliding gear piece 400, and when the driving motor is activated, the shift fork 510 continuously applies a rightward force F1 minus F3 to the sliding gear piece 400; the fork 510 always applies a force to the sliding gear member 400 rightward whether the driving motor is activated or not.

It can be further understood that the present embodiment avoids the situation that the shifting fork 510 needs to be rotated back and forth to change the contact point with the sliding gear piece 400, and then the sliding gear piece 400 is pushed leftward or the sliding gear piece 400 is pushed rightward, so that the shifting fork 510 is easily damaged, and meanwhile, the power requirement on the driving motor is also high, which increases the energy consumption and the cost; the embodiment does not need the shifting fork 510 to rotate back and forth to further push the sliding gear piece 400 to move, the power requirement on the driving motor is not large, and the energy consumption and the cost are reduced.

It can also be understood that the pushing spring 130 continuously applies a leftward force to the sliding gear member 400, and when the sliding gear member 400 moves leftward to engage with the synchronizing gear member 140 after the motor is started, sometimes the head of the tooth portion at the left end of the sliding gear member 400 and the head of the tooth portion at the right end of the synchronizing gear member 140 are pushed against each other, and the engagement cannot be completed, and then the engagement can be completed until the synchronizing gear member 140 rotates a certain angle; if a driving motor with a large power is directly used to drive the shift fork 510 to push the sliding gear member 400 to move leftward and engage with the synchronizing gear member 140, the driving motor, the sliding gear member 400 and the synchronizing gear member 140 are damaged when the above-mentioned conditions are met, and the wear of the parts is accelerated. The present embodiment employs the pushing spring 130 to apply a leftward force to the sliding gear member 400, and the driving motor only acts to offset a portion of the force applied to the switching arm 530 by the pushing torsion spring 540, so as to indirectly control the movement of the sliding gear member 400, which can greatly reduce the power required by the driving motor and reduce the wear rate of the parts.

According to some embodiments of the present invention, referring to fig. 5 and 6, the first gear member 200 includes a first inner tooth portion 210, a first shaft 230 and a first outer tooth portion 220, the right end of the first shaft 230 is fixedly connected to the first inner tooth portion 210, the left end of the first shaft 230 is fixedly connected to the first outer tooth portion 220, the first inner tooth portion 210 is engaged with the planetary gear set 120, the first outer tooth portion 220 is used for engaging with a wheel of a model car, the synchronizing gear member 140 is sleeved on the first shaft 230 and wraps the first inner tooth portion 210, and the synchronizing gear member 140 can rotate relative to the first shaft 230; the rotation of the main driving gear 110 can drive the synchronizing gear 140 to rotate, so as to drive the planetary gear set 120 to rotate, and the rotation of the planetary gear set 120 can drive the first inner tooth portion 210 to rotate, so as to drive the first shaft 230 and the first outer tooth portion 220 to rotate, and the rotation of the first outer tooth portion 220 can drive the wheel connected with the first outer tooth portion 220 to rotate.

According to some embodiments of the present invention, referring to fig. 5 and 6, the second gear 300 includes a second inner tooth 310, a second shaft 330 and a second outer tooth 320, the left end of the second shaft 330 is fixedly connected to the second inner tooth 310, the right end of the second shaft 330 is fixedly connected to the second outer tooth 320, the second inner tooth 310 is engaged with the planetary gear set 120, the second outer tooth 320 is engaged with the wheel of the model car, the second shaft 330 is provided with a second groove 331 extending along the axial direction of the second shaft 330, the sliding gear 400 is sleeved on the second shaft 330 and the sliding gear 400 abuts against the second groove 331, the sliding gear 400 can slide along the axial direction of the second shaft 330, the sliding gear 400 rotates synchronously with the second shaft 330, it can be understood that when the sliding gear 400 is sleeved on the second shaft 330, because the sliding gear 400 is partially positioned in the second groove 331 and abuts against the second groove 331, when the sliding gear 400 rotates, the sliding gear 400 abuts against the second recess 331 and the outer arc wall of the second shaft 330 at the same time, so that the rotation of the sliding gear 400 can drive the second shaft 330 to rotate synchronously.

It should be noted that the first shaft 230 is provided with the first groove 231, i.e. the first shaft 230 and the second shaft 330 may be replaced with each other.

It can be understood that when the sliding gear member 400 is not engaged with the synchronizing gear member 140, the rotation of the main driving gear can drive the synchronizing gear member 140 to rotate, thereby driving the planetary gear set 120 to rotate, while the rotation of the planetary gear set 120 can drive the second inner tooth portion 310 to rotate, thereby driving the second shaft 330 and the second outer tooth portion 320 to rotate, and the rotation of the second outer tooth portion 320 can drive the wheel connected with the second outer tooth portion 320 to rotate; when the sliding gear member 400 is engaged with the synchronizing gear member 140, the rotation of the main driving gear can drive the synchronizing gear member 140 to rotate, the rotation of the synchronizing gear member 140 can drive the sliding gear member 400 and the planetary gear set 120 to rotate, the rotation of the sliding gear member 400 drives the second shaft 330 to rotate, the rotation of the planetary gear set 120 drives the first shaft 230 to rotate, and the differential does not play a role at this time.

According to some embodiments of the present invention, referring to fig. 5 and 6, the sliding gear member 400 includes a sliding inner gear portion 410, a sliding cylinder 420, and a sliding disk 430, a left end of the sliding cylinder 420 is fixedly connected to the sliding inner gear portion 410, a right end of the sliding cylinder 420 is fixedly connected to the sliding disk 430, the sliding inner gear portion 410, the sliding cylinder 420, and the sliding disk 430 are integrally formed, the sliding inner gear portion 410, the sliding cylinder 420, and the sliding disk 430 are all sleeved on the second shaft 330, and the sliding inner gear portion 410 is engaged with or disengaged from the synchronizing gear member 140.

According to some embodiments of the present invention, referring to fig. 5 and 6, the second shaft 330 is provided with a fixed plate 332, the fixed plate 332 is sleeved and fixed on the second shaft 330, the fixed plate 332 is located on one side of the sliding disk 430 far away from the sliding inner tooth portion 410, that is, the fixed plate 332 is located on the right side of the sliding disk 430, the pushing spring 130 is sleeved on the second shaft 330, the pushing spring 130 is located between the sliding disk 430 and the fixed plate 332, two ends of the pushing spring 130 are respectively connected with the sliding disk 430 and the fixed plate 332, and the pushing spring 130 is in a compressed state, so that the pushing spring 130 continuously applies a leftward force to the sliding disk 430.

According to some embodiments of the present invention, referring to fig. 5 to 7, the fork 510 is located between the sliding inner gear 410 and the sliding disk 430, the fork 510 abuts against a side of the sliding disk 430 close to the sliding inner gear 410, that is, the fork 510 abuts against a left side of the sliding disk 430, and the pulling and inserting of the continuous and smooth sliding disk 430 applies a force to the right.

According to some embodiments of the present invention, referring to fig. 2, 4, 5 and 6, a steel bar assembly 150 is disposed at a rear side of the housing 100, the steel bar assembly 150 includes a connection seat 151 and a long steel bar 152, the long steel bar 152 is disposed through the connection seat 151 and can slide relative to the connection seat 151, the connection seat 151 is fixedly installed on the housing 100, one end of the long steel bar 152 is connected to a driving motor, the other end of the long steel bar 152 is connected to the switching arm 530, the driving motor can apply a force to the switching arm 530 through the long steel bar 152, and the driving motor applies a force to the switching arm 530 in a direction opposite to a direction of the force applied to the switching arm 530 by pushing the torsion spring 540.

It will be appreciated that the long steel bar 152 is a cylindrical long thin bar, and the connection of the long steel bar 152 to the switch arm 530 requires the long steel bar 152 to be bent off and inserted and tied to the switch arm 530.

In the description herein, references to the description of "some embodiments" mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A differential device for use with a model vehicle, comprising:

a housing (100);

a differential assembly located in the housing (100), the differential assembly including a main driving gear (110), a planetary gear set (120), a first gear (200), a synchronizing gear (140), a second gear (300) and a sliding gear (400), the main driving gear (110) being engaged with the synchronizing gear (140), the synchronizing gear (140) being sleeved on the first gear (200) and engaged with the planetary gear set (120), the planetary gear set (120) being engaged with the first gear (200) and the second gear (300), the sliding gear (400) being sleeved on the second gear (300) and capable of moving along an axial direction of the second gear (300), the sliding gear (400) and the second gear (300) rotating synchronously;

a push spring (130) located within the housing (100), the push spring (130) for continuously applying a force to the sliding gear member (400) towards the synchronizing gear member (140);

the switching assembly (500) is used for controlling the sliding gear piece (400) to be meshed with or separated from the synchronizing gear piece (140), the switching assembly (500) comprises a shifting fork (510), a switching shaft (520), a switching arm (530), a pushing torsion spring (540) and a driving motor, the switching shaft (520) penetrates through the shell (100) and can rotate relative to the shell (100), the shifting fork (510) is fixed on the switching shaft (520) and abuts against the sliding gear piece (400), one end of the switching arm (530) is fixed on the switching shaft (520), and the other end of the switching arm (530) is connected with the driving motor; both ends of the push torsion spring (540) are respectively connected to the switching arm (530) and the housing (100); the pushing torsion spring (540) is used for continuously applying force to the switching arm (530), so that the shifting fork (510) continuously applies force to the sliding gear piece (400) and the force is opposite to the synchronous gear piece (140).

2. The differential device according to claim 1, characterized in that, when the drive motor is stopped, a force applied to the sliding gear member (400) by the shift fork (510) is larger than a force applied to the sliding gear member (400) by the urging spring (130), and the sliding gear member (400) is separated from the synchronizing gear member (140); when the driving motor is started, the force applied by the driving motor to the switching arm (530) can offset part of the force applied by the pushing torsion spring (540) to the switching arm (530), so that the force applied by the pushing spring (130) to the sliding gear piece (400) is greater than the force applied by the shifting fork (510) to the sliding gear piece (400), and the sliding gear piece (400) moves to be meshed with the synchronizing gear piece (140).

3. The differential device according to claim 1, wherein the first gear member (200) includes a first inner tooth portion (210), a first shaft (230), and a first outer tooth portion (220), both ends of the first shaft (230) are fixedly connected to the first inner tooth portion (210) and the first outer tooth portion (220), respectively, the first inner tooth portion (210) is meshed with the planetary gear set (120), and the first outer tooth portion (220) is meshed with a wheel of the model car.

4. The differential device according to claim 1, wherein the second gear member (300) includes a second inner tooth portion (310), a second shaft (330) and a second outer tooth portion (320), both ends of the second shaft (330) are respectively fixedly connected to the second inner tooth portion (310) and the second outer tooth portion (320), the second inner tooth portion (310) is engaged with the planetary gear set (120), the second outer tooth portion (320) is engaged with a wheel of the model car, the sliding gear member (400) is sleeved on the second shaft (330), the sliding gear member (400) can slide along an axis of the second shaft (330), and the sliding gear member (400) and the second shaft (330) rotate synchronously.

5. The differential device according to claim 4, wherein the sliding gear member (400) includes a sliding inner gear portion (410), a sliding cylinder (420), and a sliding disk (430), both ends of the sliding cylinder (420) are respectively fixedly connected to the sliding inner gear portion (410) and the sliding disk (430), the sliding inner gear portion (410), the sliding cylinder (420), and the sliding disk (430) are integrally molded, the sliding inner gear portion (410), the sliding cylinder (420), and the sliding disk (430) are all sleeved on the second shaft (330), and the sliding inner gear portion (410) is engaged with or disengaged from the synchronizing gear member (140).

6. The differential device according to claim 5, wherein a fixed plate (332) is provided on the second shaft (330), the fixed plate (332) is fitted over and fixed to the second shaft (330), the fixed plate (332) is located on a side of the sliding disk (430) away from the sliding internal tooth portion (410), the push spring (130) is fitted over the second shaft (330), the push spring (130) is located between the sliding disk (430) and the fixed plate (332), two ends of the push spring (130) are respectively connected to the sliding disk (430) and the fixed plate (332), and the push spring (130) is in a compressed state.

7. The differential device according to claim 5, characterized in that the shift fork (510) is located between the sliding inner teeth (410) and the sliding disk (430), the shift fork (510) abutting with a side of the sliding disk (430) near the sliding inner teeth (410).

8. The differential device according to claim 1, characterized in that the housing (100) is provided with a steel bar assembly (150), the steel bar assembly (150) comprises a connecting seat (151) and a long steel bar (152), the long steel bar (152) is inserted into the connecting seat (151) and can slide relative to the connecting seat (151), the connecting seat (151) is fixedly mounted on the housing (100), one end of the long steel bar (152) is connected with the driving motor, the other end of the long steel bar (152) is connected with the switching arm (530), the driving motor can apply force to the switching arm (530) through the long steel bar (152), and the force applied to the switching arm (530) by the driving motor is opposite to the force applied to the switching arm (530) by the pushing torsion spring (540).

9. A model vehicle comprising a differential device as claimed in any one of claims 1 to 8.