KR102131630B1 - Driving apparatus for electric vehicle - Google Patents

Abstract

The present invention relates to an electric vehicle driving device. The electric vehicle driving apparatus according to the spirit of the present invention includes a driving motor and a differential gear unit disposed inside the driving motor. In addition, the differential gear unit includes a differential gear case, a side gear disposed inside the differential gear case, and a differential shaft passing through the differential gear case and connected to the side gear. At this time, a hole into which the side gear is inserted is formed in the differential shaft, and the side gear is inserted into the hole of the differential shaft.

Description

Electric vehicle driving device {Driving apparatus for electric vehicle}

The present invention relates to an electric vehicle driving device.

Recently, the development of electric vehicles using electric power as a power source has been activated by replacing automobiles using oil as a power source causing pollution. In addition, hybrid vehicles using oil and electricity as power sources are also being developed. At this time, the hybrid vehicle may be classified as one type of electric vehicle. Accordingly, it can be understood that the hybrid vehicle is included in the electric vehicle.

The electric vehicle includes a battery for supplying electric power and a driving device operated by the battery to rotate the axle. The driving device includes a driving motor that generates power through power supplied from the battery, and a gearbox that connects the driving motor and the axle. The gearbox can be understood as a device for deceleration or shifting. In detail, the power generated by the drive motor is transmitted to a gearbox, and the power transmitted from the gearbox is decelerated or shifted and transmitted to the axle.

At this time, when the size or capacity of the battery is increased, the driving efficiency of the electric vehicle may be improved. Therefore, in order to increase the size (capacity) of the battery disposed in the engine compartment of a limited size, it is necessary to reduce the volume of the driving device.

In particular, various methods for miniaturizing the drive device by changing the gear type and arrangement while maintaining the output and reduction ratio of the drive device have been proposed. For example, a method is proposed in which a differential gear, which is one component of the driving device, is built into the driving motor to reduce the volume.

In connection with the differential gear, the following prior literature has been registered.

1. Registration No.: 10-1401689 (announcement date: June 27, 2014)

2. Name of invention: Differential limit differential gear device

The prior art discloses a differential gear used in a vehicle. At this time, the differential gear is provided with a plurality of differential pinions that are engaged with each other, and rotation shafts are respectively inserted into the differential pinions.

At this time, the differential gear having such a shape is formed to have a relatively large volume. Therefore, there is a problem in that the volume of the drive motor is increased in order to place the differential gear inside the drive motor. Accordingly, there is a problem that the volume of the driving device is large and it does not secure enough space for the battery.

The present invention has been proposed to solve this problem, as the space to which the battery is mounted is maximized, the volume of the differential gear is reduced and placed in the interior of the driving motor, thereby minimizing the volume of the driving device. It is aimed at providing.

In addition, an object of the present invention is to provide an electric vehicle driving apparatus that secures a wider space in which the differential gear is disposed by arranging rotor shafts primarily connected to the driving motors on both sides of the driving motor.

In addition, an object of the present invention is to provide an electric vehicle drive device having a differential gear with sufficient rigidity in a small space so as to withstand the load of a high-power drive motor.

The electric vehicle driving apparatus according to the spirit of the present invention includes a driving motor and a differential gear unit disposed inside the driving motor. In addition, the differential gear unit includes a differential gear case, a side gear disposed inside the differential gear case, and a differential shaft passing through the differential gear case and connected to the side gear.

At this time, a hole into which the side gear is inserted is formed in the differential shaft, and the side gear is inserted into the hole of the differential shaft.

In addition, the drive motor includes a stator fixed to the housing, a rotor rotatably disposed inside the stator, and a rotor shaft coupled to the rotor and extending to both sides of the rotor.

At this time, the rotor shaft includes a first rotor shaft and a second rotor shaft spaced apart in the axial direction.

According to the present invention according to the above-described solution, there is an advantage that the volume of the differential gear can be relatively reduced and the space in which the differential gear is mounted can be relatively wide.

In detail, as the side gear is configured in such a way that it is inserted into the differential shaft, the volume of the differential gear case in which the differential gear is disposed may be reduced. Accordingly, even if the inner space of the rotor in which the differential gear case is disposed is relatively small, there is an advantage that the differential gear unit can be mounted.

In addition, as the rotor shafts are disposed on both sides of the rotor, the inner space of the rotor can be relatively wide. Accordingly, there is an advantage that the volume of the differential gear case mounted in the inner space of the rotor can be provided larger.

As a result, as the volume of the differential gear unit is reduced, there is an advantage that the size of the driving device including the driving motor can be reduced as a whole.

In addition, there is an advantage that the rigidity of the differential gear unit can be sufficiently secured as a larger differential gear unit can be mounted.

1 is a view schematically showing an electric vehicle driving apparatus according to an embodiment of the present invention.
2 is a view showing the appearance of an electric vehicle driving apparatus according to an embodiment of the present invention.
FIG. 3 is a view showing a cross-section taken along line III-III' of FIG. 2.
4 is an exploded view of a part of the configuration of an electric vehicle driving apparatus according to an embodiment of the present invention.
5 is a view showing a differential gear of an electric vehicle driving apparatus according to an embodiment of the present invention.
6 is a view schematically showing a differential gear of an electric vehicle driving apparatus according to an embodiment of the present invention in comparison with a conventional differential gear.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. It should be noted that in adding reference numerals to the components of each drawing, the same components have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing embodiments of the present invention, when it is determined that detailed descriptions of related well-known configurations or functions interfere with understanding of the embodiments of the present invention, detailed descriptions thereof will be omitted.

In addition, in describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected to or connected to the other component, but another component between each component It should be understood that may be "connected", "coupled" or "connected".

1 is a view schematically showing an electric vehicle driving apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the electric vehicle driving apparatus 1 (hereinafter, a driving apparatus) according to the spirit of the present invention includes a driving motor 10 and a gearbox. The gearbox may be understood as a configuration that transmits the driving force of the driving motor 10 to the axle.

The gear box may include a planetary gear unit 20, a differential gear unit 30 and a reduction gear unit 40. At this time, the power generated by the drive motor 10 may be transmitted to the axle along the planetary gear unit 20, the differential gear unit 30 and the reduction gear unit 40.

At this time, in the driving device 1 according to the spirit of the present invention, the differential gear unit 30 is disposed inside the driving motor 10. Further, the planetary gear unit 20 is disposed on one side of the drive motor 10, and the reduction gear unit 40 is disposed on both sides of the drive motor 10 and can be respectively connected to the axle.

In detail, the drive motor 10 includes a stator 110 and a rotor 120 disposed inside the stator 110. The stator 110 is fixedly disposed in the housing 100, and the rotor 120 is rotatably disposed. And, when power is applied to the stator 110, the rotor 120 may be rotated by electromagnetic force.

The stator 110 and the rotor 120 are provided in a cylindrical shape having a hollow inside. In detail, the stator 110 and the rotor 120 are opened inside in the axial direction (horizontal direction of FIG. 1 ). Then, the rotor 120 is disposed radially inside the stator 110, and the differential gear unit 30 is disposed radially inside the rotor 120.

In addition, the drive motor 10 includes a rotor shaft 130 extending from the rotor 120. The rotor shaft 130 may be understood as a configuration that connects the rotor 120 and the planetary gear unit 20. In particular, the rotor shaft 130 is composed of a hollow shaft, it can be rotated with the rotor 120.

The planetary gear unit 20 includes a sun gear 210, a planetary gear 200, a ring gear 220 and a carrier 230. The sun gear 210 is configured to be connected to the rotor shaft 130, and the carrier 230 is understood to be configured to be connected to the differential gear unit 30.

Further, the planetary gear 200 corresponds to a configuration connecting the sun gear 210 and the carrier 230. In detail, the planetary gear 200 may be disposed on the outer circumferential surface of the sun gear 210 to be interlocked with the sun gear 210.

In particular, the planetary gears 200 may be provided in plural, and the plurality of planetary gears 200 may be arranged spaced apart at equal intervals in a cylindrical shape. For example, three planetary gears 200 may be provided and spaced 120 degrees from the outer circumferential surface of the sun gear 210 in a circumferential direction.

In addition, the ring gear 220 is provided fixed to the housing 100. The ring gear 220 may be understood as a configuration for fixing the planetary gear 200 so that the planetary gear 200 can be rotated within a predetermined range.

Accordingly, power is transmitted to the sun gear 210, the planetary gear 200, and the carrier 230. In particular, when the rotor shaft 130 is rotated, the sun gear 210 is rotated. In addition, the planetary gear 200 may rotate in conjunction with the sun gear 210 and simultaneously orbit along the inner circumferential surface of the ring gear 220. In addition, the carrier 230 may be rotated by revolution of the plurality of planetary gears 200.

The differential gear unit 30 includes a power input shaft 310, a differential gear case 320, a differential gear 300 and a differential shaft 330. It is understood that the power input shaft 310 is connected to the carrier 230, and the differential shaft 330 is connected to the reduction gear unit 40. In addition, the differential gear case 320 and the differential gear 300 correspond to a configuration that connects the power input shaft 310 and the differential shaft 330.

Accordingly, power is transmitted to the power input shaft 310, the differential gear case 320, the differential gear 300, and the differential shaft 330. At this time, the differential shafts 330 are respectively extended to both sides in the axial direction and are respectively connected to the reduction gear unit 40. And, the reduction gear unit 40 may be connected to the axle.

Hereinafter, each configuration will be described in detail with reference to the drawings of a specific driving device.

2 is a view showing the appearance of an electric vehicle driving apparatus according to an embodiment of the present invention.

2 and 3, the driving device 1 includes a housing 100 that forms an exterior. As described above, various components are disposed inside the housing 100. In addition, structures such as the stator 110 and the ring gear 220 may be fixed inside the housing 100.

The housing 100 includes a plurality of covers 102, 104, 106, and 108 that are coupled to each other. The plurality of covers 102, 104, 106, and 108 are aligned in the axial direction, and may be coupled to each other through a plurality of fastening members 101.

In the plurality of covers, the motor case 102 accommodating the drive motor 10, the intermediate covers 104 and 106 coupled to both sides of the motor case 102, and the sides of the intermediate covers 104 and 106 A case cover 108 is coupled to each.

The intermediate cover may be divided into a first intermediate cover 104 coupled to one side of the motor case 102 and a second intermediate cover 106 coupled to the other side of the motor case 102. At this time, the first intermediate cover 104 is disposed on the side where the planetary gear unit 20 is disposed, and the second intermediate cover 106 is disposed on the side where the planetary gear unit 20 is not disposed. It can be understood as.

The case cover 108 is coupled to the first intermediate cover 104 and the second intermediate cover 106, respectively. At this time, since the case cover 108 is formed in the same way, it is not classified for convenience of description.

In the case cover 108, a case cover through hole 108a to which an axle is coupled is formed. At this time, the axle may extend into the inside of the driving device 1 through the case cover through-hole 108a, and may be coupled to the reduction gear 40. In addition, the case cover 108 may be provided with an oil injection port 109 through which oil can be injected into the drive unit 1.

FIG. 3 is a view showing a cross-section taken along line III-III' of FIG. 2.

3, the drive motor 10, the planetary gear unit 20, the differential gear unit 30 and the reduction gear unit 40 are disposed inside the housing 100.

The stator 110 and the rotor 120 are included in the driving motor 10. The stator 110 is fixed to the inside of the motor case 102, and the rotor 120 is rotatably disposed inside the stator 110.

In addition, the rotor shaft 130 is coupled to both sides of the rotor 120. The rotor shaft 130 extends axially toward the intermediate covers 104 and 106. In particular, at least a portion of the rotor shaft 130 extending toward the first intermediate cover 104 may be interlocked with the planetary gear unit 20.

The planetary gear unit 20 includes the sun gear 210, the planetary gear 200, the ring gear 220 and the carrier 230. 3, the sun gear 210 is disposed outside the rotor shaft 130. Therefore, the sun gear 210 may be rotated together by the rotation of the rotor shaft 130.

In addition, the ring gear 220 is disposed between the first intermediate cover 104 and the motor case 102. As shown in FIG. 3, the ring gear 220 may be fixed by being coupled to one side of the motor case 102.

In addition, the planetary gear 220 is disposed between the sun gear 210 and the ring gear 220. 3 shows a cross section of the driving device 1, only one planetary gear 220 is illustrated, but the planetary gear 220 may be provided in plural.

In addition, the carrier 230 is coupled to the planetary gear 220 and rotates together. Further, the differential gear unit 30 may be coupled to the center side of the carrier 230 to be interlocked with each other.

The differential gear unit 30 includes the power input shaft 310, the differential gear case 320, the differential gear 300 and the differential shaft 330. As shown in FIG. 3, the differential gear case 320 and the differential gear 300 are disposed inside the rotor 120.

Therefore, the power input shaft 310 is provided to extend in an axial direction from one side of the rotor 120 to the inside of the rotor 120. In detail, one end of the power input shaft 310 is coupled to the carrier 230 and the other end is coupled to the differential gear case 320.

In addition, the differential shaft 330 extends from inside to outside of the rotor 120. At this time, the differential shaft 330 is provided as a pair extending in both axial directions. Then, the differential shaft 330 may be coupled to the reduction gear unit 40 to be interlocked with each other. At this time, the power input shaft 310 is provided as a hollow shaft so that the differential shaft 330 can be disposed therein.

The reduction gear unit 40 includes a first reduction gear 400 coupled to the differential shaft 330 and a second reduction gear 410 interlocked with the first reduction gear 400. At this time, the number of gear teeth of the second reduction gear 410 may be greater than the number of gear teeth of the first reduction gear 400. Therefore, power may be decelerated in the process of transferring from the first reduction gear 400 to the second reduction gear 410.

In addition, various ball bearings, a fixing structure, an oil passage, and the like may be further provided inside the housing 100. Such a structure is generally used and its description is omitted.

Hereinafter, the rotor shaft 130 of the driving motor 10 will be described in detail with reference to FIG. 3.

4 is an exploded view of a part of the configuration of an electric vehicle driving apparatus according to an embodiment of the present invention.

4, the rotor shaft 130 includes a first rotor shaft 132 coupled to one side of the rotor 120 and a second rotor shaft coupled to the other side of the rotor 120. 134 is included. At this time, the first rotor shaft 132 and the second rotor shaft 134 are disposed spaced apart from each other in the axial direction. That is, the rotor shaft 130 is provided in a pair of components spaced apart from each other.

In general, the rotor shaft of the drive device for an electric vehicle penetrates the interior of the rotor and extends to both sides. On the other hand, the rotor shafts 130 of the drive unit 1 for an electric vehicle according to the spirit of the present invention are spaced apart from each other and extend from each side of the rotor 120 respectively. Accordingly, the inner space of the rotor 120 may be widened by a space where the rotor shaft 130 is spaced apart.

In addition, the differential gear unit 30 disposed inside the rotor 120 may be provided in a larger volume. In detail, the differential gear case 320 is disposed inside the rotor 120. In addition, the first rotor shaft 132 and the second rotor shaft 134 are disposed on both sides of the differential gear case 320, respectively. That is, the rotor shaft 130 is not disposed between the differential gear case 320 and the rotor 120 (radial direction).

Accordingly, the differential gear case 320 may be provided with a larger volume. In addition, the differential gear case 320 and the differential gear 300 disposed therein may be formed to have sufficient rigidity.

In addition, even if the size of the drive motor 10 including the rotor 120 is reduced, it is possible to secure an internal space in which the differential gear unit 30 can be installed. Accordingly, the overall size of the driving device 1 can be reduced.

The first rotor shaft 132 and the second rotor shaft 134 correspond to a hollow shaft provided through the inside in the axial direction. The power input shaft 310 and the differential shaft 330 are disposed inside the first rotor shaft 132. In addition, the differential shaft 330 is disposed inside the second rotor shaft 132.

Hereinafter, the differential shaft disposed inside the first rotor shaft 132 is referred to as a first differential shaft 332, and the differential shaft disposed inside the second rotor shaft 134 is a second differential shaft 334 ). In addition, the first differential shaft 332 may be understood as an axis disposed inside the power input shaft 310.

In addition, the first rotor shaft 132, the first front end portion 1320 which is inserted into the interior of the rotor 120 and the first end which is the other end opposite to the first front end 1320. End 1322 is included. The sun gear 210 is coupled to the outside of the first rear end portion 1322.

At this time, the sun gear 210 is disposed inside the first intermediate cover 104. Therefore, it can be understood that the first rotor shaft 132 extends from the one side of the rotor 120 to the first intermediate cover 104.

In addition, the second rotor shaft 134, the second front end portion 1340 inserted into the interior of the rotor 120 and the second end portion opposite to the second front end portion 1340, the second end End 1342 is included. The second rear end 1342 is rotatably disposed in the second intermediate cover 106. In other words, the second rotor shaft 134 extends from the other side of the rotor 120 to the second intermediate cover 106.

At this time, the first rotor shaft 132 may extend longer in the axial direction than the second rotor shaft 134. This can be understood that the first rotor shaft 132 is coupled to the planetary gear unit 20.

Hereinafter, the differential gear 300 of the differential gear unit 30 will be described in detail with reference to FIG. 4.

5 is a view showing a differential gear of an electric vehicle driving apparatus according to an embodiment of the present invention. FIG. 5 is an enlarged view of the differential gear 300 and the differential shaft 330 illustrated in FIG. 4, and for convenience of description, only a part of the differential shaft 330 is illustrated.

As shown in FIG. 5, the differential gear 300 includes a pair of side gears 302 and 304, a pair of auxiliary gears 306, and an auxiliary shaft 308.

The pair of side gears 302 and 304 and the pair of auxiliary gears 306 may be rotated in cooperation with each other. Further, the pair of side gears 302 and 304 are coupled to the differential shaft 330, and the pair of auxiliary gears 306 are coupled to the auxiliary shaft 308.

The pair of side gears includes a first side gear 302 coupled with the first differential shaft 332 and a second side gear 304 coupled with the second differential shaft 334. At this time, the first differential shaft 332 and the second differential shaft 334 may be arranged spaced apart from each other on a straight line in the axial direction. In addition, the first side gear 302 and the second side gear 304 are disposed spaced apart in the axial direction facing each other.

The auxiliary shaft 308 is disposed between the first side gear 302 and the second side gear 304. Accordingly, the first differential shaft 332, the first side gear 302, the auxiliary shaft 308, the second side gear 304 and the second differential shaft 334 are sequentially arranged in the axial direction. Can be understood as

At this time, the differential shaft 330 and the auxiliary shaft 308 are disposed perpendicular to each other. That is, the auxiliary shaft 308 is disposed to extend in a radial direction perpendicular to the axial direction. The pair of auxiliary gears 306 are disposed above and below the auxiliary shafts 308, respectively. Accordingly, the upper and lower sides of the first and second side gears 302 and 304 may be interlocked with the auxiliary gear 306.

In addition, the differential gear 300 is disposed inside the differential gear case 320. That is, the differential gear case 320 is disposed inside the rotor 120, and the differential gear 300 is disposed inside the differential gear case 320.

The differential gear case 320 may be provided in a cylindrical shape having an internal space. In addition, the differential gear case 320 includes a first case 322 and a second case 324 coupled to each other. The first case 322 and the second case 324 are provided in the same shape and are arranged to face in the axial direction.

At this time, the first differential shaft 332 penetrates the first case 322 in the axial direction and extends into the differential gear case 320. In addition, the second differential shaft 334 extends into the differential gear case 320 through the second case 334 in the axial direction.

In addition, upper and lower ends of the auxiliary shaft 308 are coupled to the differential gear case 320. In detail, the auxiliary shaft 308 is disposed between the first case 322 and the second case 334. Then, as the first case 322 and the second case 334 are coupled, the auxiliary shaft 308 may be fixed.

In addition, the power input shaft 310 is coupled to the first case 322. In detail, the second case 334 and the auxiliary shaft 308 are coupled to one side of the first case 322, and the power input shaft 310 is coupled to the other side.

Therefore, the power transmitted from the power input shaft 310 is transmitted to the first case 322 and the second case 334 coupled with the auxiliary shaft 308. Then, the pair of auxiliary gears 306 coupled to the auxiliary shaft 308 is rotated, and the first and second side gears 302 and 304 engaged therewith are rotated. In addition, power may be transmitted to the first and second differential shafts 332 and 334 coupled to the first and second side gears 302 and 304.

6 is a view schematically showing a differential gear of an electric vehicle driving apparatus according to an embodiment of the present invention in comparison with a conventional differential gear. Fig. 6(a) shows a conventional differential gear, and Fig. 6(b) shows a differential gear of the present invention.

The differential gear 400 illustrated in FIG. 6A includes a pair of side gears 402 and 404 and a pair of auxiliary gears 406. In addition, a differential shaft 432 is connected to the pair of side gears 402 and 404, respectively. For convenience of description, a cross section of a differential shaft 432 coupled to one side gear 402 is shown.

Referring to Figure 6 (a), the differential shaft 432 is inserted into the side gear 402 is coupled. In detail, a hole into which the differential shaft 432 is inserted is formed in the side gear 402, and the differential shaft 432 is inserted into the hole of the side gear 402. Therefore, the side gear 402 is formed in an umbrella shape with a round head and a recessed rear side.

The differential gear 300 illustrated in FIG. 6B includes a pair of side gears 302 and 304 and a pair of auxiliary gears 306. In addition, a differential shaft 332 is connected to the pair of side gears 302 and 304, respectively. For convenience of description, a cross section of the differential shaft 332 coupled to one side gear 302 is shown.

Referring to (b) of FIG. 6, the side gear 302 is inserted into and coupled to the differential shaft 332. In detail, a hole into which the side gear 302 is inserted is formed in the differential shaft 332, and the side gear 302 is inserted into the hole of the differential shaft 332. Therefore, the side gear 302 is formed in a mushroom shape with a round head and a rear side protruding.

The differential gear 400 shown in FIG. 6(a) and the differential gear 300 shown in FIG. 6(b) are compared. For comparison, FIG. 6 shows a conventional differential gear 400 and a differential gear 300 of the present invention to have the same diameter and tooth thickness.

Accordingly, the side gear 402 of Fig. 6(a) and the side gear 302 of Fig. 6(b) have the same tooth surface. This tooth surface was shown with a one-dot chain line, and the same length and the same angle.

At this time, in the case of Fig. 6 (a), the tooth surface is formed from the outer peripheral surface of the differential shaft 432 to the outside. Accordingly, a tooth surface is formed in a trapezoidal shape together with the front surface of the differential shaft 432. Such a shape is formed because the differential shaft 432 is inserted into the side gear 402.

On the other hand, in the case of Fig. 6 (b), a tooth surface is formed in front of the differential shaft 332. Accordingly, the tooth surface and the differential shaft 332 are spaced apart, so that the tooth surface is formed in a substantially triangular shape. This shape is formed because the side gear 302 is inserted into the differential shaft 332.

Accordingly, the side gear 302 of FIG. 6(b) has a smaller diameter in the radial direction less than the side gear 402 of FIG. 6(a). In other words, the diameter may be reduced by the diameter of the differential shaft 432 in FIG. 6A.

And, the auxiliary gear 306 of Figure 6 (b) is spaced at a smaller interval than the auxiliary gear 406 of Figure 6 (a). In other words, the auxiliary gear 306 of FIG. 6(b) is displaced by H in the radial direction from the auxiliary gear 406 of FIG. 6(a).

Accordingly, the length of the auxiliary shaft 308 on which the auxiliary gear 306 is installed is shortened, and the radial length of the differential gear case 320 can be reduced. In other words, the differential gear case 320 may be formed with a smaller volume. Therefore, even if the space inside the rotor 120 is small, the differential gear case 320 may be disposed. In other words, larger differential gears 300 may be disposed in the same space.

In addition, the diameter R2 of the differential shaft 332 in FIG. 6B is larger than the diameter R1 of the differential shaft 432 in FIG. 6A (R2>R1). The diameter of the differential shaft 432 in FIG. 6A affects the formation of the tooth surface, as described above. Therefore, when the diameter of the differential shaft 432 is increased, the diameter of the side gear 402 is increased.

As a result, the volume of the differential gear case in which the differential gear 400 is installed becomes large, and it is difficult to mount it inside the rotor 120. That is, in FIG. 6(a), it is difficult to secure the diameter of the differential shaft 432 largely.

On the other hand, in the case of the differential shaft 332 of Figure 6 (b), it does not affect the formation of the tooth surface. In addition, it must be provided with a relatively large diameter so that the side gear 302 can be inserted into the differential shaft 332. Accordingly, a large diameter of the differential shaft 332 can be formed, and sufficient rigidity can be secured.

As a result, through the shape of the differential gear unit 30, it can be installed in a relatively small installation space, and has the advantage of being able to secure a relatively large rigidity.

1: Driving device 10: Driving motor
20: planetary gear unit 30: differential gear unit
40: reduction gear unit 130: rotor shaft
300: differential gear 302, 304: side gear
320: differential gear case 330: differential shaft

Claims (15)

Drive motor; And
The differential gear unit disposed inside the drive motor; is included,
In the differential gear unit,
Differential gear case;
A side gear disposed inside the differential gear case; And
Includes; a differential shaft passing through the differential gear case and connected to the side gear;
A hole in which the side gear is inserted is formed in the differential shaft, and the side gear is inserted in a hole in the differential shaft,
In the drive motor,
A stator fixed to the housing;
A rotor rotatably disposed inside the stator; And
It is coupled to the rotor, the rotor shaft extending to both sides of the rotor; includes,
A drive device for an electric vehicle, wherein the rotor shaft includes a first rotor shaft and a second rotor shaft spaced apart in the axial direction around the differential gear case. delete According to claim 1,
The differential gear case is disposed inside the rotor,
The first rotor shaft and the second rotor shaft is a driving device for an electric vehicle, characterized in that disposed on both sides of the differential gear case. According to claim 1,
The first rotor shaft includes a first front end inserted into the rotor and a first rear end facing the first front end,
The second rotor shaft, the driving device for an electric vehicle, characterized in that it includes a second front end and a second rear end facing the second front end inserted into the rotor. The method of claim 4,
A planetary gear unit disposed on one side of the driving motor is further included,
The first rear end is a drive device for an electric vehicle, characterized in that connected to the planetary gear unit. The method of claim 4,
In the housing,
A motor case in which the stator is installed; And
Includes; intermediate cover coupled to both sides of the motor case,
The second rear end is a driving device for an electric vehicle, characterized in that it is rotatably disposed on the intermediate cover. According to claim 1,
The housing, the stator, the rotor and the differential gear case are sequentially arranged from radially outer to inner,
A drive device for an electric vehicle, characterized in that the first rotor shaft, the differential gear case and the second rotor shaft are sequentially arranged in the axial direction. According to claim 1,
The differential shaft includes a first differential shaft disposed inside the first rotor shaft and a second differential shaft disposed inside the second rotor shaft,
The side gear includes a first side gear connected to the first differential shaft and a second side gear connected to the second differential shaft. The method of claim 8,
In the differential gear unit,
A pair of auxiliary gears disposed inside the differential gear case and interlocked with the first side gear and the second side gear; And
Drive unit for an electric vehicle, characterized in that further comprises; an auxiliary shaft coupled to the differential gear case and the pair of auxiliary gears installed. The method of claim 9,
The auxiliary shaft is disposed between the first side gear and the second side gear,
The pair of auxiliary gears are spaced apart from the upper and lower sides of the auxiliary shaft,
The pair of auxiliary gears, the driving device for an electric vehicle, characterized in that the first side gear and the second side gear are interlocked in contact with the upper and lower sides, respectively. The method of claim 9,
A planetary gear unit disposed on one side of the driving motor and transmitting power of the driving motor; And
Power input shaft for connecting the planetary gear unit and the differential gear case; is further included,
The power input shaft is a drive device for an electric vehicle, characterized in that disposed between the first rotor shaft and the first differential shaft. According to claim 1,
A planetary gear unit disposed on one side of the driving motor; And
A reduction gear unit disposed on both sides of the driving motor; is further included,
Power generated by the drive motor is a drive device for an electric vehicle, characterized in that transmitted to the axle along the planetary gear unit, the differential gear unit and the reduction gear unit. The method of claim 12,
The differential shaft includes a first differential shaft and a second differential shaft extending from the inner side of the drive motor to both sides so as to be connected to the reduction gear unit,
The side gear includes a first side gear inserted into and coupled to the first differential shaft and a second side gear inserted into and coupled to the second differential shaft. Following paragraph 13,
The first differential axis and the second differential axis are spaced apart from each other on a straight line in the axial direction,
The first side gear and the second side gear are driving devices for an electric vehicle, characterized in that disposed to face each other and spaced apart in the axial direction. The method of claim 14,
A driving device for an electric vehicle, characterized in that one side of the first side gear and the second side gear protrudes toward the first differential shaft and the second differential shaft, respectively.

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