CN104648140B - Drive device for the rear wheels of a four-wheel drive electric vehicle - Google Patents

Abstract

A kind of drive device of trailing wheel for four-wheel driving electric vehicle is provided, it can minimize driving power loss during four-wheel drive, and can be produced by preventing the load based on differential gear, prevent from driving power loss during two-wheel drive.The drive device includes：First motor；Motor interior axle, it is arranged on also cross the first motor inside the first motor, and one end is connected to trailing wheel；Train of reduction gears, it is connected to the first motor；Differential gear, it includes the right differential gear for being connected to motor interior axle and the differential box for being connected to train of reduction gears；Separator input shaft, its one end is connected to the left differential gear of differential gear, and the other end is connected or disconnects with wheel hub；Wheel speed sensors；Controller, it exports the signal for separator input shaft to be connected to wheel hub；Motor driver；Second motor；Selector fork, it is connected to the second motor；And sleeve, it is connected to selector fork, and separator input shaft and wheel hub are connected to each other/are disconnected.

Description

Drive device for the rear wheels of a four-wheel drive electric vehicle

technical field

Aspects of the invention relate to a drive device for a rear wheel of a four-wheel drive electric vehicle. More particularly, aspects of the present invention relate to a driving device for a rear wheel of a four-wheel drive electric vehicle, which can synchronize the rotation speed of an input shaft based on a first motor decoupler with that of a hub based on a rear wheel, Minimizes loss of drive power during four-wheel drive by transmitting drive power to the rear wheels based on the splitter input shaft instead of the clutch, and can be achieved by connecting a differential between the reduction gear set and the splitter input shaft , to prevent load generation based on the differential device, and to prevent loss of driving power during two-wheel drive.

Background technique

Generally speaking, according to the driving mode, four-wheel drive vehicles can be divided into two-wheel drive mode and four-wheel drive mode.

First, a two-wheel drive vehicle will be described. Depending on the actual driven wheels in the engine and transmission layout, two-wheel drive vehicles are classified as rear engine rear drive (RR) systems, front engine front drive (FF) systems, or front engine rear drive (FR) systems.

Since the RR system is generally applied only to a sports car, rather than a usual passenger car or a sports utility vehicle (SUV), two-wheel drive vehicles can be roughly divided into FF system and FR system modes.

FF cars and FR cars are similar to each other in that their invention engine and transmission are mounted on the front side of the car, but the layout is different. That is, an FF car is generally constructed such that its engine and transmission are mounted on lateral sides of the car to transmit power to the front wheels through a differential unit integrally formed with the transmission. An FR car is generally constructed such that its engine and transmission are arranged in the front-rear direction of the car to transmit power from the transmission to the rear wheels through a drive shaft.

Next, a four-wheel drive vehicle will now be described. To supply the proper amount of engine drive power to the four wheels, four-wheel drive vehicles employ clutches, transmission devices, and differentials. According to the transmission method of the transmission, four-wheel drive vehicles are divided into part-time four-wheel drive vehicles and full-time four-wheel drive vehicles. In a part-time 4WD vehicle, the power to the front wheels is switched manually. In a full-time 4WD vehicle, the four wheels are driven constantly.

In a four-wheel drive vehicle, power from the engine is distributed to the front and rear wheels. As shown in FIG. 1 , electric vehicles, including hybrid vehicles, generally utilize driving power generated from a separate motor M driven by a battery B instead of driving power generated from an engine E and transmitted to rear wheels. The driving power generated from the engine E is transmitted to the transmission TM, and then applied to the front wheels through the differential device D.

FIG. 2 is a perspective view of a conventional drive device for rear wheels of the conventional four-wheel drive electric vehicle shown in FIG. 1 .

As shown in Fig. 2, this traditional driving device comprises: motor 1, it produces rotational power to drive automobile; First driving gear 2, it is connected to the rotating shaft of motor 1; First driven gear 3, it and first driving gear Gear 2 meshes; second drive gear 4, which is coaxially coupled to first driven gear 3; second driven gear 5, which meshes with second drive gear 4; clutch 6, which is coaxially coupled to The second driven gear 5, and transmits or blocks driving power; and the differential gear 7, which is connected to the clutch 6, to transmit the driving power to two wheels.

With this configuration, the conventional drive device operates as follows. When the motor 1 is driven, the power generated from the motor 1 is transmitted to the first driving gear 2 and firstly decelerated by the first driven gear 3 meshing with the first driving gear 2 .

The power decelerated for the first time by the first driven gear 3 is transmitted to the second drive gear 4 coaxially coupled with the first driven gear 3 , and is transmitted by the second driven gear 5 meshed with the second drive gear 4 . Slow down a second time.

The power decelerated for the second time by the second driven gear 5 is coaxially coupled to the second driven gear 5, and then transmitted to the clutch 6 for transmitting or blocking the driving power. The front wheels of the car are driven by power generated from a front wheel drive motor (not shown) or an engine (not shown), and the car runs. Then, if the power is transmitted by the clutch 6 for four-wheel drive, by means of the differential gear 7 connected to the clutch 6, the power is transmitted to the two rear wheels, thereby achieving four-wheel drive.

However, in the conventional driving device, since the power is transmitted using the clutch, driving power loss may occur due to slippage between friction plates in the clutch.

In addition, in the conventional driving device, since the differential gear is connected between the clutch and the rear wheels, a load originating from the differential gear may be generated during two-wheel drive using the front wheels, resulting in loss of driving power.

Contents of the invention

Aspects of the present invention provide a driving device for the rear wheels of a four-wheel drive electric vehicle, which can pass through the splitter-based The input shaft rather than the clutch transmits drive power to the rear wheels, minimizing loss of drive power during four-wheel drive.

Other aspects of the present invention provide a driving device for rear wheels of a four-wheel drive electric vehicle, which can prevent a load based on a differential device by connecting a differential device between a reduction gear set and a splitter input shaft. produced, while preventing loss of drive power during two-wheel drive.

According to one aspect of the present invention, there is provided a driving device for the rear wheels of a four-wheel drive electric vehicle, the driving device includes: a first motor for generating rotational power; an inner shaft of the motor, the inner shaft of the motor is installed on The inside of the first motor, while passing through the first motor, and one end is connected to the rear wheel; a reduction gear set, the reduction gear set is connected to the first motor; a differential device, the differential The transmission includes a right differential gear connected to the inner shaft of the motor and a differential case connected to the reduction gear set; a splitter input shaft, one end of which is connected to the left side of the differential a differential gear, the other end of which is connected to or disconnected from the hub; a wheel speed sensor, which detects the rotational speed of the wheels; and a controller, which outputs a signal for connecting the splitter input shaft to the hub a motor driver connected to the controller; a second motor connected to the motor driver; a shift fork connected to the second motor; and a sleeve that is connected to the shift fork and that connects/disconnects the splitter input shaft and the hub to each other.

The reduction gear set may include: a first driving gear connected to the first motor; a first driven gear meshed with the first driving gear; Two driving gears, the second driving gear is coaxially connected to the rotation shaft of the first driven gear; and a second driven gear, the second driven gear is connected between the second driving gear and the differential Mesh between boxes.

The second motor may be a linear motor.

The controller controls the revolutions per minute (RPM) of the first motor by comparing a wheel speed input via a wheel speed sensor with a motor speed input from an internal sensor of the first motor, thereby making the RPM based on the The rotational speed of the splitter input shaft of the first motor is synchronized with the rotational speed of the hub based on the rear wheels.

The controller may switch the mode of the first motor from RPM control to torque control after the hub and the decoupler input shaft are connected to each other.

After the hub and the decoupler input shaft are connected to each other, rotational power based on the inner motor shaft of the first motor may be directly transmitted to the decoupler input shaft through a differential gear of the differential gear .

The second driven gear may be a ring gear.

As described above, according to the present invention, it is possible to transmit driving power to the rear wheels by using the clutch input shaft instead of the clutch after synchronizing the rotation speed of the first motor-based splitter input shaft with the rotation speed of the rear wheel-based hub. Minimizes loss of drive power during four-wheel drive.

In addition, it is possible to prevent loss of driving power during two-wheel drive by preventing generation of a load based on the differential device by connecting the differential device between the reduction gear set and the splitter input shaft.

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

Description of drawings

In conjunction with the accompanying drawings, the purpose, features and advantages of the present invention will be more clearly understood from the following detailed description, wherein:

Fig. 1 is a schematic diagram of a traditional four-wheel drive electric vehicle;

FIG. 2 is a perspective view of a conventional driving device for the rear wheels of the conventional four-wheel drive electric vehicle shown in FIG. 1;

3 is a cross-sectional view of a drive device for a rear wheel of a four-wheel drive electric vehicle according to an embodiment of the present invention; and

FIG. 4 is a diagram illustrating a connection device between a drive device for rear wheels and a differential device in the four-wheel drive electric vehicle shown in FIG. 3 .

detailed description

Hereinafter, examples of embodiments of the present invention will be described in detail with reference to the accompanying drawings so that they can be easily understood and used by those skilled in the art. Advantages and features of the present invention and a method of achieving them will be more readily understood by referring to the following detailed description of the preferred embodiments and accompanying drawings.

However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims. In addition, it is understood that the terms used, such as those defined in commonly used dictionaries, should not be limited to the usual dictionary meanings, but should be interpreted as having the same meaning as the present invention on the basis that the inventor can define appropriate term concepts to best express the principles of the invention. There is a meaning consistent with the meaning in the context of the technical and the present disclosure.

3 is a cross-sectional view of a driving device for the rear wheels of a four-wheel drive electric vehicle according to an embodiment of the present invention; A diagram of the connection between the drive unit and the differential unit.

As shown in Figures 3 and 4, the drive device for the rear wheels of a four-wheel drive electric vehicle according to an embodiment of the present invention includes: a first motor 11 for generating rotational power; a motor inner shaft 16 installed on the second The inside of a motor 11, while passing through the first motor 11, and one end connected to the rear wheel; the first driving gear 12, which is connected to the first motor 11; the first driven gear 13, which meshes with the first driving gear 12 ; the second drive gear 14, which is coaxially coupled to the rotating shaft of the first driven gear 13; the second driven gear 15, which meshes with the second drive gear 14; the differential device 17, which comprises a shaft connected to the motor inner The right differential gear 17b of 16 and the differential case 17a connected to the second driven gear 15; the separator input shaft 18, one end of which is connected to the left differential gear 17c of the differential device 17, and the other end is connected with the wheel hub 19 or Disconnect; wheel speed sensor 20, which detects the wheel rotation speed; controller 21, after the rotation speed of the splitter input shaft 18 based on the first motor 11 is synchronized with the rotation speed of the hub 19 based on the rear wheel, the controller 21 outputs an output for the The splitter input shaft 18 is connected to the signal of the wheel hub 19, thereby driving the rear wheels; the motor driver 22, which is connected to the controller 21; the second motor 23, which is connected to the motor driver 22; the shift fork 24, which is connected to the second A motor 23; and a sleeve 25 which is connected to the shift fork 24 and which connects/disconnects the splitter input shaft 18 and the hub 19 to each other.

The second motor 23 may include a linear motor.

The second driven gear 15 may include a ring gear.

With this configuration, the drive device for the rear wheels of a four-wheel drive electric vehicle according to an embodiment of the present invention operates as follows.

When the four-wheel drive electric vehicle is only driven by the front wheels, that is, when the rear wheels are operated as driven wheels, the sleeve 25 does not connect the hub 19 and the splitter input shaft 18 to each other, thereby preventing the splitter input shaft 18 from moving. The rotational power is transmitted to the hub 19. Accordingly, driving power loss due to resistance from the first motor 11, the reduction gear sets 12, 13, 14, and 15, and the differential device 17 can be prevented, thereby improving fuel consumption.

In the case that the rear wheels are to be driven for four-wheel drive, that is, in the case that the rear wheels are operated as driving wheels, the controller 21 drives the first motor 11 through the motor driver 22 . If the first motor 11 is driven in this way, the rotational power of the first motor 11 is decelerated by the first driving gear 12, the first driven gear 13, the second driving gear 14, and the second driven gear 15, and then the rotation difference The differential case of the transmission 17, thereby rotating the splitter input shaft 18. Next, the controller 21 controls the revolutions per minute (RPM) of the first motor 11 by comparing the rear wheel speed input via the wheel speed sensor 20 with the motor speed input from an internal sensor of the first motor 11, thereby The rotational speed of the decoupler input shaft 18 based on the first motor 11 is synchronized with the rotational speed of the hub 19 based on the rear wheel.

If the rotational speed of the splitter input shaft 18 based on the first motor 11 is synchronized with the rotational speed of the hub 19 based on the rear wheel by controlling the RPM of the first motor 11, the controller 21 drives the second motor 23 to allow the sleeve 25 to When the shift fork 24 is slightly moved to the splitter input shaft 18 , the hub 19 and the splitter input shaft 18 are connected to each other, thereby transmitting the rotational power of the splitter input shaft 18 to the hub 19 .

After the hub 19 and the decoupler input shaft 18 are connected to each other in this manner, the controller 21 switches the control mode of the first motor 11 from RPM control to torque control. From the perspective of the torque-controlled differential 17, there is no speed difference between the right differential gear 17b and the left differential gear 17c. Therefore, the rotational power based on the inner motor shaft 16 of the first motor 11 is transmitted to the rear wheels, and directly transmitted to the splitter input shaft 18 through the differential gears 17b and 17c of the differential device 17, and then transmitted to the wheel hub 19, thereby drive the rear wheels.

As described above, during four-wheel drive, after the rotation speed of the splitter input shaft 18 based on the first motor 11 is synchronized with the rotation speed of the hub 19 based on the rear wheels, by using the splitter input shaft 18, the drive power is transmitted to the rear wheels, rather than clutches, thereby minimizing drive power losses.

While the present invention has been described in relation to specific exemplary embodiments, it will be understood by those skilled in the art that the invention is not limited to the disclosed embodiments, but is intended to be encompassed within the spirit and scope of the appended claims and their equivalents various modifications.

Claims (6)

1. a kind of drive device of trailing wheel for four-wheel driving electric vehicle, the drive device includes：

First motor, for producing rotational power；

Motor interior axle, the motor interior axle is arranged on the inside of first motor, also cross first motor, and one End is connected to the trailing wheel；

Train of reduction gears, the train of reduction gears is connected to first motor；

Differential gear, the differential gear includes being connected to the right differential gear of the motor interior axle and is connected to the reducing gear The differential box of wheel group；

Separator input shaft, one end of the separator input shaft is connected to the left differential gear of the differential gear, the other end It is connected with wheel hub or is disconnected；

Wheel speed sensors, the wheel speed sensors detect vehicle wheel rotational speed；

Controller, the controller exports the signal for the separator input shaft to be connected to the wheel hub；

Motor driver, the motor driver is connected to the controller；

Second motor, second motor is connected to the motor driver；

Selector fork, the selector fork is connected to second motor；And

Sleeve, the sleeve connection to the selector fork, and the separator input shaft and the wheel hub are connected to each other/ Disconnect,

Wherein, after the wheel hub is connected to each other with the separator input shaft, the controller is by first motor Pattern is switched to moment of torsion control from revolutions per minute RPM controls.

2. drive device as claimed in claim 1, wherein, the train of reduction gears includes：

First drive gear, first drive gear is connected to first motor；

First driven gear, first driven gear is engaged with first drive gear；

Second drive gear, second drive gear is coaxially connected to the rotating shaft of first driven gear；And

Second driven gear, second driven gear is engaged between second drive gear and the differential box.

3. drive device as claimed in claim 1, wherein, second motor is linear motor.

4. drive device as claimed in claim 1, wherein, the controller is by comparing by means of the wheel speed sensors Vehicle wheel rotational speed is input into the motor rotary speed input with the internal sensor from first motor to control first motor Revolutions per minute RPM, thus makes the rotating speed of the separator input shaft based on first motor and is based on the trailing wheel The synchronization of the wheel hub.

5. drive device as claimed in claim 1, wherein, it is connected to each other it with the separator input shaft in the wheel hub Afterwards, the rotational power of the motor interior axle based on first motor is directly transmitted by the differential gear of the differential gear To the separator input shaft.

6. drive device as claimed in claim 2, wherein, second driven gear is ring gear.